(PDF) Author Index to Abstracts - DOKUMEN.TIPS (2024)

Abstracts

tion in basic CFD and in-vitro study was the goal of the project. Methods:Comparative investigations for 3 three-leaflet valves were performed. Thefirst valve’s leaflets were symmetrical and its generating lines were straight.The next two ones had modified, asymmetrical leaflets to work as a direc-tor for blood backflow, providing better washout around the stent and theirgenerating lines were accordingly straight and arc lines. All valves weremounted in cylinder housings for physical experiments. Researches com-prised CFD simulations with ADINA and laser visualisations on laboratorytesters. Computed and measured values of fluid velocities in selected criti-cal areas were compared. The fluid with physical features close to the bloodwas used. Results: For the first, simple valve, areas at the bottom of the stentwith low fluid velocities were observed. Very similar results for both modi-fied valves were obtained, with better washout around the stent. The 20%increase of local fluid velocities was confirmed for areas of the lowest veloc-ity values. The valve with straight generating lines had slightly betteropening field. Conclusions: Results obtained allow to state that presentedvalve modifications will significantly reduce clots formation risk in areas ofworse washout. Performing of animal experiments is necessary to verify thestatement.

O 002 DURABILITY TESTING OF A POLYMERIC BILEAFLETMECHANICAL HEART VALVE PROSTHESISD. Medart, T. Schmitz-Rode, U. Steinseifer. Helmholtz Institute for Bio-medical Engineering, Applied Medical Engineering, Aachen University andUniversity Hospital, GermanyAim: Currently, 95% of all implanted mechanical heart valve prosthesesconsist completely or at least partially of Pyrolytic Carbon. In order todevelop a mechanical heart valve prosthesis made out of alternative mate-rials a special hinge design is used to integrate tribomaterials in the highlyloaded areas of the leaflets. Methods: The wear behaviour of different mate-rial couples is investigated in vitro. Wear testing was performed using a spe-cially designed durability tester that controls the pressure difference aboutthe closed heart valve prostheses. The testing conditions were set accordingto FDA and ISO standards for heart valve testing. A qualitative assessmentof the wear behavior was performed using light microscopy and scanningelectron microscopy at intervals of 10, 40 and every following 50 millioncycles. Results: None of the investigated heart valve prostheses failed duringthe durability tests. Compared to the reference valve made out of polymericmaterials wear especially in the hinges can be reduced clearly by using acompound material. Conclusions: The wear behavior of a mechanical heartvalve prosthesis made out of polymeric materials can be optimized by aleaflet design which enables an integration of tribomaterials in the highlyloaded hinges of the leaflets. Durability tests have to go on to confirm thepromising durability behavior of the novel heart valve prosthesis.

O 003 IN VITRO CALCIFICATION OF STENTLESS BIOPROSTHE-SES: COMPARISON OF 5 GLUTARALDEHYDE FIXATED VS. 5MEDTRONIC PROTOTYPES CALLED IDEFIXM. Krings1,4, F. Everaerts2, M. Torrianni2, M. Hendriks3, B. Glasmacher1,4.1Helmholtz-Institute for Biomedical Engineering Aachen, Germany2Medtronic Heart Valves Division, Santa Ana, CA, USA 3Medtronic BakkenResearch Center, Maastricht, Nederland 4IZKF “BIOMAT”, Aachen,GermanyAim: Calcification is the main problem with respect of the long termoutcome of valve replacement by biological valves. Even the stentless valvesstill suffer by this problem. A crucial importance is the fixation method ofthe bioprostheses. The so called IdeFix method is a new carbodiimide basedmethod. We compared 5 common glutaraldehyde (GA) fixated vs. 5 IdeFixfixated porcine bioprostheses with respect to the calcification of the hearthvalves prostheses. Methods: 5 glutaraldehyde fixated bioprostheses and 5Medtronic IdeFix fixated porcine aortic heart valves were subjected toaccelerated dynamic in vitro calcification for up to 8 weeks (24 millioncycles) at HIA under nearly physiological conditions (pH 7.4, DP 100 mm Hg, calcium- and phosphate concentration in physiological range).

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Artificial Organs29(9):716–787, Blackwell Publishing, Inc.© 2005 International Center for Artificial Organs and Transplantation

Abstracts from the ESAO-IFAO Joint Congress October 5–8, 2005 Bologna, Italy*

ORAL PRESENTATIONSSubject Abstract #

Heart Valves O 001–007Artificial and Bioartificial Liver O 008–014Dialysis Detoxification O 015–021Symposium Artificial Liver O 022–027Modeling and Simulation O 028–031Dialysis O 032–035Promising Concepts O 036–042Heart Pumps O 043–049Cell Therapy O 050–056Clinical Aspects of Dialysis O 057–064Assist Devices O 065–071Bioreactors O 072–078Organ Transplantation O 079–082Polymers and Scaffolds O 083–086Symposium Tissue Engineering O 087–092Dialysis O 093–098Cardiac Assist O 099–105Nanotechnology O 106–112Extracorporeal Circulation Modeling O 113–119Heart O 120–125

POSTER PRESENTATIONSSubject Abstract #

Polymers and Scaffolds P 001–010Polymers and Scaffolds 2 P 011–020Dialysis P 021–031Heart P 032–041Dialysis 2 P 042–052Dialysis 3 P 053–062Heart 2 P 063–072Heart 3 P 073–082Organ Transplantation P 083–092Artificial Liver P 093–103Organ Transplantation 2 P 104–113Artificial Liver 2 P 114–124Tissue Engineering P 125–134Modeling P 135–144Tissue Engineering 2 P 145–154Tissue Engineering 3 P 155–162Artificial Lung P 163–172Heart and Circulation Modeling P 173–182

ORAL PRESENTATIONS

Heart Valves

O 001 COMPARATIVE STUDY OF MODIFIED POLYURETHANEVALVES FOR CARDIAC ASSIST DEVICESA. Jarosz, W. Bujok, A. Kapis, R. Kustosz. Foundation for Cardiac SurgeryDevelopment, Zabrze, PolandAim: The major problem with PU leaflets valves for heart support devicesis thrombus formation in areas of low blood washout, especially at thebottom of the stent. Various constructions of valve-housing complex wereused to reduce the risk. Evaluation of the POLVAD’s PU valve modifica-

*Reprinted with permission from the International Journal of ArtificialOrgans.

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Leaflet calcification was detected 2 dimensionally, weekly, non destructivelyby means of microradiography (7 mAs, 22 kV). The wall calcification wasdetected, fortnightly by Spiral-CT at Diagnostic Radiology at RWTH-Aachen. For the data analysis computer programs from HIA were used.Results: Wall and leaflet calcification of IdeFix-Prototypes was significantlylower compared to GA-fixated bioprostheses. There was nearly no calcifi-cation for the prototypes. For both groups there was full function of everyprosthesis until the end of test. Conclusion(s): The calcification problems ofbioprostheses seemed to be solved, especially for the in vitro testing methodat HIA. Advanced tests will show the suitability for every day use of thisfixation method.

O 004 IN VITRO THROMBOGENICITY INVESTIGATION FORMECHANICAL HEART VALVESC. Kim, K. Hamilton, H. Reul†, U. Steinseifer, T. Schmitz-Rode. HelmholtzInstitute for Biomedical Engineering, RWTH Aachen University, Aachen,GermanyBackground/Aim: After the implantation of mechanical heart valves(MHV), the risk of thrombus formation continues to be a significantproblem. Therefore it is necessary for the optimal design of MHVs to local-ize and analyze their critical areas, which can cause initial thrombus forma-tion. A test system was specifically designed and developed for the in vitrodetermination of the thrombotic effects in MHVs. Methods: This thrombo-genicity test system enables the in vitro testing of 2 types of MHVs simul-taneously with a minimal blood volume of 1 liter. The two tested MHVs areplaced in a fluid-optimized and biocompatible chamber, which is separatedfrom the air chambers by two identical and biocompatible silicone-mem-branes. With the help of periodic air pressure changes in the air chambersthe two silicone membranes can be displaced. By this displacement of themembranes, the test fluid is circulated in the chamber through two oppo-sitely positioned MHVs. During the testing, the ACT (Activated ClottingTime) is determined periodically to check the thrombogenicity potential ofthe test blood. The pressure difference up and downstream of both valvesis measured continuously to monitor the functioning of the valves. Results:The results of pressure measurements show the pressure differences up anddownstream of the MHV, which initially decrease and then increase whenthe thrombus formation begins to develop at the MHV. The regions of theinitial thrombus formation at the MHV could be observed after the test.Conclusion: The results of this test system show good correspondence to theresults of the animal tests and supply the information about the optimaldesign of the newly developed MHV.

O 005 ARTIFICIAL HEART VALVES, OSCILLATION AND SHEARSTRESSESA.A. Sakhaeimanesh. Biomedical Engineering Group University ofIsfahan, IranIntroduction: In artificial heart valves, the problems of haemolysis, plateletdestruction, thrombus formation, perivalvular leakage and endothelialdamages are directly related to the fluid dynamic characteristics of flow pastartificial heart valves. In this study the effect of oscillation on elevating tur-bulent shear stresses through the jellyfish and St. Vincent valves has beeninvestigated. Methods: In a mock circulation, flow was driven by a servo-controlled piston pump (VSI pump) that compressed the ventricle to sim-ulate the physiological flow. A model of the left ventricle and load wasincorporated with the drive unit for testing artificial valves in the aortic posi-tion under practical flow and loading conditions. Results and Discussion:Comparison between two valves revealed that at 0.5D downstream of thevalves the magnitude of shear stresses in the Jellyfish valve were muchhigher than those of the St. Vincent valve at cardiac outputs of 4, 5.5 and6.5 l/min. Furthermore, at 3D and 5D downstream of the Jellyfish valve themagnitudes of shear stresses reduced dramatically to 4 and 1 N/m2 respec-tively at cardiac output of 6.5 l/min. At 3 and 5D downstream of the St.Vincent valve, on the other hand, showed maximum shear stresses of thevalues of 49 and 16 N/m2 respectively at the same cardiac output. It ishypothesized that the cause of high shear stresses in close proximity to theJellyfish valve was due to the oscillation of the membrane which in turn gen-erated a wake downstream of the valve and produced a wide region of dis-turbance further downstream. This resulted in further pressure drag andconsequently, higher pressure drops across the valve and higher shearstresses downstream of the valve. This idea was supported by the results ofshear stress and pressure drop measurements. Maximum and mean shearstresses at 0.5D downstream of the Jellyfish valve were about twice those

of the St. Vincent valve and pressure drops across the Jellyfish valve wereup to 93% higher than those of the St. Vincent valve under steady flow ratesbetween 10 to 26 l/min. Turbulent intensities at close vicinity of the St.Vincent valve (0.5D) were much less than those of the Jellyfish valve. Thiscan be attributed to the fact that solid occluder of the St. Vincent valve didnot produce vibration in the downstream flow field which consequentlyresulted in low shear stress estimations.

O 006 3D PIV MEASUREMENTS OF PROSTHETIC HEARTVALVES FLUID DYNAMICSR. Kaminsky1,3, M. Rossi2, U. Morbiducci2,4, L. Scalise2, P. Castellini2,S. Kallweit3, P. Verdonck1, M. Grigioni4. 1Institute Biomedical Technology,Ghent University, Belgium, 2Universita Politecnica delle Marche, Ancona,Italy, 3ILA GmbH, Jülich, Germany, 4Technology and Health Department,Istituto Superiore di Sanità, Rome, ItalyThe pulsatile flow field downstream of two different mechanical prostheticheart valve models, 25 and 27 mm tissue annulus diameter, respectively, wasinvestigated by means of stereoscopic particle image velocimetry (PIV)technique. With respect to conventional PIV, that allows the measurementof the in-plane components of the velocity, the stereoscopic PIV configura-tion yields also the out-of-plane component. The availability of planar threecomponent velocity fields significantly enhances the capability of measur-ing and analysing 3D flows in a correct and detailed manner. The stereo-scopic PIV in vitro investigation was performed under pulsatile flowconditions, in a mock loop properly designed to guarantee optimal opticalaccess, and equipped with an optically clear valve housing segment to allowunobstructed laser measurements. We measured the flow at peak systole, intwo crosssectional planes parallel to the valvular plane, located 1 and 3 cmdownstream of this last, so that the out-of-plane structures in the velocityfield correspond to the main direction of the flow. This choice was suggestedby the fact that it has been widely assessed that the mixing process, as theone associated to prosthetic valves fluid dynamics, is intimately connectedwith the transient of turbulence: the streamwise vortices generated in a jetflow, in addition to ring type vortices, have been found to mix fluid streamseven more efficiently. Good statistics was assured by choosing an adequatesample size. The stereoscopic PIV technique allowed to evaluate andcompare the three-dimensionality of the flow field downstream of two pros-thetic valve models, and to catch the specific features of both the jets and the vortical structures in the chosen planes of investigation. Future aimis the characterization of the 3D flow field by means of a planar scansion ofthe flow field downstream of the valve.

O 007 CFD SIMULATION OF A NOVEL BILEAFLET MECHANI-CAL HEART VALVE PROSTHESISY. Yokoyama1, D. Medart2, C. Schmitz2, P.B. Kwant2, U. Steinseifer2,T. Schmitz-bode2, S. Takatani1. 1Institute of Biomaterial and Bioengineering,Tokyo Medical and Dental University, Tokyo, Japan, 2Institute for Biomed-ical Technologies Helmholtz-institute Aachen, Aachen, GermanyBackground/Aim: Aim of this study is the investigation of the flow fielddownstream of a novel bileaflet heart prosthesis made out of polymetricmaterials. The HIA-Bileaflet(HIA-BL) valve exhibits several special fea-tures to optimize the hydrodynamic performance of the valve. Method: Todetermine flow characteristics downstream of the novel HIA-BL, the flowwas analyzed by using: 1) Flow visualization by applying hydrogen bubbletechniques 2) Computational Fluid Dynamics(CFD) simulation in fullyopened position 3) LDA analysis of the flow field to validate CFD-data.Results: The HIA-BL valve shows an evenly distributed velocity profileacross the aortic cross section with small wakes downstream of the leaflets.Flow velocity near the aortic wall is near zero indicating that the flow reat-taches to the aortic wall after passing the HIA-BL valve without separationand recirculation. Conclusion: CFD is a strong tool to get an inside viewinto the flow field of biomedical devices. In this study, the investigation ofthe flow field downstream of the HIA-BL valve was conducted by usinghydrogen bubble techniques, CFD and LDA analysis. Results show a goodcorrelation between LDA and CFD analysis and enable a good insight viewinto the flow field downstream of the HIA-BL valve.

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Artif Organs, Vol. 29, No. 9, 2005

Artificial and Bioartificial Liver

O 008 EFFECT OF EXTRACORPOREAL LIVER SUPPORT SYS-TEMS ON SERUM CYTOKINE LEVELSV. Stadlbauer1, P. Krisper1, B. Haditsch1, R. Aigner2, R.E. Stauber1.1Department of Internal Medicine, Medical University of Graz, 2Division ofNuclear Medicine, Medical University of Graz, AustriaIntroduction: Cytokines play an important role in acute-on-chronic liverfailure (ACLF). The use of extracorporeal liver support systems may bebeneficial in ACLF. Two systems, the Molecular Adsorbents RecirculatingSystem (MARS, M) and Fractionated Plasma Separation, Adsorption and Dialysis (Prometheus, P) are currently available. MARS eliminatescytokines, but the serum levels before and after treatment did not differ(Sen 2004). The aim of this study was to compare the effect of M and Ptreatments on serum cytokine levels. Methods: Eight patients with acute-on-chronic liver failure underwent alternating treatments with either M orP in a randomized cross-over design. Thirty-four treatments (16 M, 16 P)were available for analysis. Serum samples were obtained before and aftereach treatment. IL6 was analyzed by a chemoluminescent assay (DPC), IL8,IL10, TNFa, and TNFaR were analyzed by the respective ELISA (Bio-medica). Results are given as median and range; groups were compared byt-test,Wilcoxon or Mann-Whitney test as appropriate. Results: Serum levelsof IL6 [39.8 (14.4–267) pg/ml], IL8 [234 (124–734) pg/ml], IL10 [16 (5–46)pg/ml] and TNFa-R [20.8 (9.6–50) pg/ml] were significantly elevated at thebeginning of the treatments, whereas TNFa [7.8 (3.4–13) pg/ml] levels werewithin normal range. No significant changes in IL6, IL8, TNFa, and TNFaRserum levels were found after treatment with M or P. IL10 showed a significant increase during M treatments (231 Æ 301 pg/ml, p < 0.05). Nochanges in cytokine levels between the first and last treatment could beseen. When patients who survived, were compared with those who did not,no difference was found in IL6, IL8, IL10, and TNFa levels at baseline or after treatment. However, TNFaR showed a significant increase (19.8 Æ24 pg/ml, p < 0.05) after treatment in the group of non-survivors. Conclu-sion: Neither M nor P caused any changes in proinflammatory serumcytokine levels. IL10 levels slightly increased during M but did not changeduring P. The observed lack of effect on serum cytokine levels may be dueto a high rate of cytokine production during the treatment. Further studiesare necessary to investigate the effect of extracorporeal liver supportsystems on cytokines and its clinical significance.

O 009 HYDRODYNAMIC BEHAVIOUR OF SEVERAL TYPES OFFLUIDIZED BED BIOREACTOR USED IN A BIOARTIFICIALLIVERR. Baudoin1, A. Gautier1, S.M. Coward2, B. David1, H.J.F. Hodgson2,C. Selden2, C. Legallais1. 1UMR CNRS Biomecanique et Genie Biomedical,Universite de Technologie de Compiegne, Compiegne, France, 2Centre forHepatology, Royal Free & Uni. College Med. School, London, U.K.Introduction: Fluidized bed bioreactors offer an environment of low shearstress and high mass transfer suitable for high density culture of encapsu-lated cells. They present an alternative to hollow fiber bioreactors previ-ously used in bioartificial livers tested to date. Previous results have shownthe importance of theoretical modelling of the hydrodynamic behaviour tooptimise the design of such a bioreactor. Aim: The purpose of the presentstudy was to compare experimental data collected under different condi-tions with the theoretical fluidized bed expansion laws. Methods: Differenttypes of alginate beads (diameter 0.4 mm up to 1 mm) of different concen-trations (1 to 2.2% alginate) and different densities, were perfused with avariety of fluids (saline solution, culture medium, plasma) in the bioreac-tors. The density of the beads was adjusted by the addition of 10–50 mm glassbeads at the time of encapsulation. The initial and final bed heights at arange of flow rates were measured. Results: We established both theoreti-cal and experimental curves showing the relationship between bead density(from 1025 to 1070 kg/m3), superficial perfusion velocity (from 10-4 to 10-3

m/s) and bed expansion ratio (1.12 to 3). In all the cases, the theoretical datawere confirmed by the experiments. Conclusions: The model developedhere allows for the design of a fluidised bed bioreactor that will have optimalfluidisation properties, while meeting the specifications for volume and flowrate required for use in a bioartificial liver.

O 010 ASSESSMENT OF OXYGEN AVAILABILITY IN THE AMC BIOARTIFICIAL LIVER USING COMPUTATIONAL FLUIDDYNAMICSG. Mareels1, P. Poyck2, S. Eloot1, R. Chamuleau2, P. Verdonck1. 1Institute Bio-medical Technology, Ghent University, Gent, Belgium 2Departments ofExperimental Surgery and Hepatology, AMC Academic Medical Center,University of Amsterdam, Amsterdam, The NetherlandsAim: To assess the oxygen (O2) availability in the AMC Bioartificial Liver(AMC-BAL) and to determine the effect of the plasma flow rate and theO2 content (pO2) of the culture gas on hepatocyte survival. Methods: TheAMC-BAL is a cylindrical bioreactor in which a non-woven polyestermatrix mat containing functional active hepatocytes is spirally woundaround a massive inner core. Between the windings of the spiral mat, gascapillaries are positioned to supply additional O2 to the hepatocytes. Plasmaflows in the void spaces between the mat windings and the capillaries. Twocharacteristic unit volumes of the AMC-BAL geometry are identified andcreated into three-dimensional computer models. A unit volume consists ofa piece of mat with capillaries organized either in an in-line pattern (at eachcorner) or in a triangular pattern (at two corners and one on the other sidein the middle). The mat is modeled as a hom*ogeneous porous zone with anexperimentally determined hydraulic permeability. O2 convection, diffusionand consumption is numerically solved (Fluent 6). O2 diffusivity throughthe non-woven mat is determined numerically. O2 consumption is im-plemented using non-linear Michaelis-Menten kinetics. Results: Using standard flow conditions, the triangular capillary pattern results in higheraverage O2 consumption compared to the in-line pattern, indicating ahigher possible hepatocyte survival rate within the matrix. Higher flow ratesand culture gas pO2 increase O2 consumption in a non-linear way: doublingthe standard flow rate and the culture gas pO2 increases average O2 con-sumption by 10% and 20%, respectively. Conclusions: A CFD model tostudy O2 transport and consumption in a bioreactor was developed andapplied to two unit volume models of the AMC-BAL. Simulation resultsshow that increasing flow rate and culture gas pO2 may contribute toincrease hepatocyte survival in the AMC-BAL.

O 011 BIOARTIFICIAL HUMAN LIVER CELL SYSTEMS: DATA-BASED IDENTIFICATION OF PERFORMANCE PREDICTORSM. Pfaff1, K. Zeilinger2, W. Schmidt-Heck3, R. Guthke3, S. Toepfer1,D. Driesch1, G. Pless2, P. Neuhaus2, J.C. Gerlach2,4. 1BioControl Jena GmbH,Jena, Germany, 2Division of Experimental Surgery, Charité CampusVirchow-Klinikum, Universitätsmedizin Berlin, Germany 3Leibniz Institutefor Natural Product Research and Infection Biology—Hans Knoell Insti-tute, Jena, Germany 4Departments of Surgery and Bioengineering,McGowan Institute for Regenerative Medicine, University of Pittsburgh,PA, USAAim: Data obtained from the operation of a bioartificial human liver cellbioreactor for extracorporeal liver support was analysed by reverse engi-neering methods to identify predictors of the long-term performance of thebioreactor culture. Data analysed originated from up to 86 bioreactor runswith primary human liver cells. Methods: Different network reconstructionmethods were applied to elucidate interrelations between the bioreactorperformance and the measured variables. The analysis included the recon-struction of correlation networks, rule-based networks, Bayesian networksand differential equation systems. Prior to this, cluster analysis of the vari-ables’ time courses (kinetics) was carried out to typify their dynamics.Results: The analysis yielded that no single kinetic variable of the 33 inves-tigated (15 biochemical ones and 18 amino acids) is better suited to predictall long-term bioreactor performance levels (low, medium, high) than galac-tose, followed second by urea. This can already be reliably done after 3 daysand with some error even after 1 day of bioreactor operation. Of the aminoacids at least two, methionine and leucine, are jointly required to reliablypredict all three performance levels. The network analysis also yielded thatfor high performance runs many strong correlations exist between the vari-ables’ kinetics, while for medium and low performance runs this is not thecase, i.e. there is a substantial breakdown in the network’s interconnectionswhen the system is not functioning at high performance level. Conclusion:The results obtained demonstrate the high potential of the applied reverseengineering methods to identify performance predictors and elucidatenetwork structures of bioartificial systems. The methods and results cantherefore be used to further improve predictability and reliability of thebioreactor’s operation with respect to its clinical application for extracor-poreal liver support.

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O 012 FIRST IN VITRO COMPARISON OF TWO BIOARTIFICIALLIVER SUPPORT SYSTEMS: MELS CELLMODULE AND AMC-BALP.P.C. Poyck1, G. Pless2, R. Hoekstra1,3, S. Roth2, A.C.W.A. van Wijk1,R. Schwartlander2, T.M. van Gulik1, I.M. Sauer2, R.A.F.M. Chamuleau4.1Dept. Surgery (Surgical Laboratory), 3AMC Liver Center and 4Dept.Hepatology, AMC, Amsterdam, The Netherlands; 2Dept. Surgery, CampusVirchow Klinikum, Charite Universitätsmedizin Berlin, GermanyBackground: Clinically applied bioartificial liver support (BLS) systems aredifficult to compare in terms of overall hepatocyte-specific function andtheir effect on clinical outcome. Particularly, the large variability in cell typeand isolate, test set-up, patient population, outcome parameters and differ-ences in data presentation hamper simple device comparison. In this study,two clinically applied BLS systems, the Modular Extracorporeal LiverSupport (MELS) CellModule and the AMC-bioartificial liver (AMC-BAL),have been compared in an in vitro set-up. Methods: Ten billion of freshlyisolated porcine hepatocytes were loaded in the MELS and the AMC-BAL(n = 4) and cultured for seven days at 37°C in the same culture medium.The overall in vitro functionality of both bioreactors was assessed at day 1,2, 4, and 7. Hepatocyte-specific functions (ammonia and lidocaine elimina-tion, urea and albumin production), hepatocellular cell damage (LDH andAST release) and general metabolic activity (oxygen and glucose con-sumption, and lactate production) were determined during a four hour testperiod. Results: In general, both bioreactors functioned well with anaverage decrease of 9.7% in the hepatocyte-specific functions over 7 days.Lidocaine elimination at day 1 and 2 was significantly higher in the AMC-BAL. All other parameters at all days did not differ significantly betweenboth bioreactors. Despite this observation, some trends were observed. Atendency towards a higher ammonia elimination was seen in the AMC-BALin all days, whereas a lower glucose consumption and lactate production wasobserved in the MELS at day 4 and 7. AST and LDH release showed a ten-dency to be higher at day 1 in the AMC-BAL. Conclusion: This first in vitrocomparison of two clinically applied BLS systems (MELS CellModule andAMC-BAL) shows comparable functional capacity over a period of sevendays.

O 013 STANDARDIZED BIOREACTOR FOR HEPATOCYTESWITH 3D CAPILLARY MEMBRANE STRUCTUREI. Guido, K. Affeld, J. Hengstler, A. Bauer, U. Kertzscher, L. Goubergrits,P. Scharfschwerdt, T. Timmel. Biofluidmechanics Laboratory, Clinic of Cardiovascular Surgery, Charité Universitätsmedizin Berlin, GermanyBackground: Bioartificial liver devices (BAL) are used to treat patients withend-stage liver disease and to bridge them until they either recover orreceive a transplant. In these devices, patient plasma is circulated extracor-poreally through a bioreactor that houses metabolically active hepatocytes.The goal is to maintain the hepatocytes optimally so that they carry out asmany activities as possible. In monolayer cell cultures the mass flow of gasesand nutrients can be achieved by diffusion alone. But for cultivating hepa-tocytes, a three dimensional structure is favourable. In a three dimensionalstructure transport by diffusion has to be supported by convection. This isdone in a bioreactor of a BAL which should be standardized for compari-son reasons. Standardization requires a design adapted to modern fabrica-tion methods to ensure a reliable and constant quality. Further requirementsare a microscopy window to observe the cells and scalability. Methods: ABAL with a network of artificial capillary membranes with defined pores isdesigned. The pores permit the passage of molecules needed by the hepa-tocytes. Two kinds of capillary membranes are used: Oxyplus PMP90 for gastransfer and MicroPES TF10 for transfer of nutrition molecules. The lattercapillary type is used to generate a convective flow inside the perfusionchamber of the BAL. The capillary membrane layers are mounted on baseplates made of PVC. This method permits variable stacking and thus a vari-able cell volume. The stacking of the plates is done with a semi-automatedbonding process. To find the proper spacing of the capillaries, a numericalsimulation of convective diffusion of solute transport in the BAL has beenperformed. The perfusion system for the BAL consists of a pump for theperfusion solution and a gas mixing device. Results: The calculation of theflow rate through the capillary and pores, the pressure in the perfusionchamber and the transmembrane resistance compare well with experimen-tal results. The convective diffusion leads to a more efficient and more evenoxygen distribution inside the perfusion chamber than diffusion alone.Experiments with human hepatocytes show the possibility to cultivate livercells in the newly designed bioreactor.

O 014 EARLY EXPERIENCES WITH A PORCINE AND CRYO-PRESERVED HUMAN HEPATOCYTE-BASED BIOARTIFICIALLIVER IN ACUTE HEPATIC FAILURE PATIENTSG. Azzena1, L. Valieri1, G. Resta1, A. Cariani1, M. Brogli2, P. Scoletta1,D. de Tullio1, R. Ragazzi1,A. Cavallari3, S. Faenza4,A. Santoro5, G. Gerunda6,A.D. Pinna7. 1Surgical Clinic Institute, University of Ferrara, 2RanD S.r.L.,3University of Bologna, 4Unit of Nephrology and Dialysis, S. Orsola-Malpighi Hospital, Bologna, 5Department of Surgery, University ofBologna, 6University of Modena and Reggio Emilia, 7Department ofSurgery and Transplantation, University of Bologna, ItalyBackground: Orthotopic liver transplantation (OLT) is the only effectivetherapeutic modality in severe acute hepatic failure (AHF). The scarcity oforgans for transplantation leads to an urgent necessity for temporary liversupport treatments in AHF patients. A hepatocyte-based bioartificial liver(BAL) is under investigation with the main purpose to serve as bridgingtreatment until a liver becomes available for OLT, or to promote sponta-neous liver regeneration. A novel radial-flow bioreactor (RFB) for three-dimensional, high-density hepatocyte culture was developed. A porcine (P-)and a cryopreserved human hepatocyte (H-) BALs were developed. Humanliver cells were isolated from livers unwanted for transplantation. Methods:After isolation liver cells were cryopreserved, then warmed up to 37°Cbefore loading into the RFB. 9 AHF patients in grade III-IVcoma waitingfor urgent OLT were treated: P-BAL was used 8 times in supporting for6–24 hours 7 patients, H-BAL was used for 4–6 hours on 2 patients. Results:The procedures were well tolerated; improvement of the encephalopathylevel, decrease in serum ammonia, transaminases and improvement of theprothrombin time, with full neurological recovery after OLT were found. 6of 7 patients treated with P-BAL underwent OLT, 1 died before transplan-tation. After the H-BAL procedure, 1 patient underwent OLT, 1 had spon-taneous liver regeneration. Conclusions: This initial experience confirms thesafety of fresh porcine BAL configuration and suggests its clinical efficacyas a temporary liver support system in AHFpatients. Human cryopreservedliver cells showed less viability then porcine ones; H-BAL showed appar-ently less impact on blood biochemical parameters and clinical effects onpatients. More investigations are needed to improve the viability and bio-logical activity of cryopreserved human cells isolated from organs unwantedfor transplantation.

Dialysis Detoxification

O 015 EFFECTS ON BLOOD RHEOLOGY CAUSED BY MACRO-MOLECULES AND THEIR APHERETIC ELIMINATION:RHEOSPECIFITY OF RED BLOOD CELL (RBC) AGGREGATESDEPENDING ON THE STRENGTH OF AGGREGATING FORCEST. Kirschkamp1,2,3,W.W. Goebel2,T. Perkkiö2, H. Schmid-Schönbein2. 1IZKFBIOMAT–Interdiciplinary Center for Clinical Research, University ofTechnology, 2Dept. of Physiology, University of Technology, 3Dept. of Ophthalmology, University Clinics, Aachen, GermanyBackground/Aim: The aim was to analyse the rheological properties ofstrongly aggregating RBC (inducible by alpha-2-macroglobulin) and mod-erately aggregating RBC (inducible by fibrinogen). Methods: In vitro, theRBC aggregate geometry was determined for strong and moderate aggre-gation inducing macromolecules. In vivo, the flow behaviour of RBC aggre-gates was analysed by intravital microscopy: Using network scanning, thenumber of perfused and non perfused microvessels can be determined.Results: Higher adhesive forces of strongly aggregating RBC led to a higherdeformation and packing density of single RBC within the aggregates. Invivo, only high aggregating RBC persisted in the precapillary bed and ledto a non-attendance up to 40% of nutritive capillaries. Conclusions: Ourdata support that procedures eliminating alpha-2-macroglobulin in theblood might provide more efficient improvement of overall blood fluidityin microvessels. The filtration procedure using the Diamed Rheopheresistechnique has been successfully applied for this aim.

O 016 THE USAGE OF BIOSPECIFIC HEMOSORBENT FORSELECTIVE REMOVAL OF ACTIVATED SERINE PROTEINASESIN CASE OF ABDOMINAL SEPSIS OF DIFFERENT ORIGINV.V. Kirkovsky, I.M. Rovdo, G.A. Lobacheva, A.K. Korolik. ByelorussianState Medical University, Minsk, BelarusThe imbalance in a proteinases-inhibitors system is recognized as a keyelement of pathological alterations in purulent inflammatory diseases, e.g.abdominal sepsis (AS). The rationale for application of proteinases

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inhibitors for such situation is well-known. Therefore, the usage of efferentmethods based on eliminating the active forms of proteinases from bloodseems to be promising. The aim of our work was to study the efficiency ofa biospecific antiproteinases hemosorbent “Ovosorb” in case of AS. As aligand in this sorbent was used the ovomucoid from the whites of duck eggs,immobilized in the polyacrylamide gel. Patients with AS of different originadmitted to the surgical departments in Minsk hospitals were studied. Allpatients were treated with a complex program including the surgical inter-vention, traditional drug therapy and hemosorbtion (HS). HS was carriedout for 60 min at a blood flow rate of 60–80 ml/min after general intravenousheparinization (125 ± 25 IU/kg body mass). The vein-venous type of hemo-perfusion was used. The sorbent Ovosorb in a volume of 40 ml was placedin a specially designed extracorporeal unit. The time intervals between suc-cessive HS sessions (from 4 hours to 2 days) and the number of sessionswere decided in each specific case. The laboratory assays were made of thetotal protein, albumin, urea and “middle molecules” substances (MMS) inthe blood. Also, the trypsin-like activity (TLA) and concentrations of a1-proteinase inhibitor (a1-PI) and a2-macroglobulin (a2-M) in plasmawere measured. After blood perfusion through an extracorporeal unit withOvosorb was revealed a significant reduction of TLA up to 2 times, MMSup to 50%, urea up to 30%. Also, Ovosorb has not influenced distinctly onthe concentrations of total protein, albumin, a1-PI and a2-M. These lab find-ings were accompanied by a reduction of clinical signs of endogenous intox-ication and regression of functional disorders in an overwhelming majorityof patients within the next few days after HS. The lethality in the patientstreated with biospecific hemosorbtion Ovosorb was 6.2%. As a result, wecan conclude that the biospecific antiproteinase hemosorbent Ovosorbshowed its high efficiency in the therapy of patients with AS of differentorigin and may be viewed as a tool of pathogenic therapy in AS of differ-ent origin.

O 017 CONTINUOUS HEMODIAFILTRATIOON WITH POLY-METHYL METHACRYLATE MEMBERANE HEMOFILTER(PMMA-CHDF) FOR TREATMENT OF PATIENTS WITH HYPERCYTOKINEMIA-RELATED PATHOPHYSIOLOGYH. Hirasawa, S. Oda, H. Shiga, K. Matsuda, M. Nakamura. Department ofEmergency and Critical Care Medicine, Chiba University Graduate Schoolof Medicine, Chiba, JapanBackground: We have reported that PMMA-CHDF could effectively andcontinuously remove various cytokines from blood stream of a patientmainly through mechanism of adsorption of cytokines to hemofilter mem-brane and that such removal of cytokines was associated with decrease inblood level of pro- and anti-inflammatory cytokines. Therefore we appliedPMMA-CHDF on patients with hypercytokinemia-related pathophysiologysuch as severe sepsis, septic shock, ARDS and severe acute pancreatitis(SAP) even when those patients had no renal dysfunction. Methods: 132patients with hypercytokinemia-related pathophysiology were treated withPMMA-CHDF regardless of their renal functions. Those patients included32 patients with severe sepsis and/or septic shock, 39 patients with ARDSand 32 patients with SAP, respectively. The hypercytokinemia was diagnosedwhen a patient had interleukin-6 (IL-6) blood level higher than 1000 pg/mL.PMMA-CHDF was continued until IL-6 blood level decreased to less than 100 pg/mL or until a patient showed improvement in general conditionand/or recovery from organ dysfunctions. The standard operational condi-tions of CHDF was as follows: blood flow rate 80–120 mL/min, dialysate flowrate 500–2000 mL/hr, and filtration rate 300–1000 mL/hr, respectively.Results: PMMA-CHDF could be applied even on the critically ill withbleeding tendency without causing serious adverse event. Patients receivedconventional treatment for each pathophysiological condition addition toPMMA-CHDF. In the majority of the patients blood levels of variouscytokines were decreased and general condition was improved, and organdysfunction was recovered. In septic shock patients, blood pressure wasreturned to normal range within 2 hours after the initiation of PMMA-CHDF. The survival was significantly improved among the patients whor*ceived PMMA-CHDF compared to the patients who received only con-ventional treatment. Conclusion: PMMA-CHDF may be an effective treat-ment for the patients with hypercytokinemia-related pathophysiology suchas severe sepsis septic shock, ARDS and SAP and may be applied on thosepatients even when they have no renal dysfunction.

O 018 PREVALENCE OF HEPATITIS AND HUMAN IMMUNODE-FICIENCY VIRUS INFECTION IN PATIENTS ON MAINTENANCEHEMODIALYSISM.H. Polenakovic1, A. Sikole1, M. Kalajdziska2, L. Simjanovska3,P. Dzekova1, G.D. Efremov3. 1Department of Nephrology, Clinical Centre,Medical Faculty, Skopje; 2Department of Virology, National Institute forHealth Protection, Skopje; 3Research Centre for Genetic Engineering and Biotechnology, Macedonian Academy of Sciences and Arts, Skopje;Republic of MacedoniaChronic dialysis patients remain a high-risk group for acquiring hepatitis Bvirus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus(HIV) infection. The aim of this work was investigation of the prevalenceof HBV, HCV and HIV infection in patients on chronic hemodialysis. Some200 sera from patients on maintenance hemodialysis were examined. Thefollowing markers were determined: anti-HCV antibodies, HBsAg, anti-HBs antibodies, anti-HBc antibodies, HIV-1 and HIV-2 antigens and anti-bodies. The methods used for determination were ELISA and ELFA. Fordetermination of HCV, Amplicor test kit (Roche Diagnostics), and the in-house developed RT/PCR method were applied. HCV genotypes weredetermined by dot blot hybridization using genotype specific profiles: probe1 (5¢-CGCTCAATGCCTGGA GAT-3¢), probe 2 (5¢-CACTCTATGCCCGGCCAT-3¢), and probe 3 (5¢-CGC TCAATACCCAGAAAT-3¢). Serumlevels of alanine aminotrasferase, aspartate aminotranferase and bilirubinwere also determined in each patient. Positive sera for anti-HCV were 109(54.5%); 19 (9.5%) were positive for HBsAg; 86 (43%) were positive foranti-HBs antibodies and 114 (57%) were positive for anti-HBc antibodies.Only 34 (17%) sera were negative for HBV and HCVmarkers. HCV andHBV co-infection was found in 9 patients. All 200 sera were negative forHIV-1 and HIV-2, both for antigens and antibodies. The results indicated ahigh prevalence of HCV infection among patients on hemodialysis, 96.6%being of genotype 1 and 3.4% of undetermined genotype. The prevalenceof HBV infection was also significant. Over the past 30 years, we did nothave a single HIV positive patient. The HCV infection correlated positivelywith the number of blood transfusions given to the patients, and with thedialysis duration time. The nosocomial type of transmission was probablythe dominant way of HCV spread in the dialysis unit. We would recommendstrict enforcement of the universal measures for infection control, and sep-aration of positive from the negative patients.

O 019 INTRACTABLE PRURITUS IN PATIENYS WITH HCV.PERSONAL EXPERIENCESG. Novelli, L. Poli, R. Predagostini, S. Martelli, Q. Lai, L. Novelli,G. Mennini, S. Ginanni Corradini, P.B. Berloco. II Clinica Chirurgica Universita La Sapienza, Roma, ItalyIntractable pruritus is one of the most common symptoms of chronic liverdisease, especially experienced by patients with prolonged cholestasis. It canbecome the most distressing symptom in patients affected by chronic liverdisease, causing a reduction in quality of life, interfering with daily activi-ties and leading to sleep deprivation or contributing to psychological dis-turbances up to suicide ideation. Therefore non-responding to medicaltherapy pruritus is an indication for liver transplantation. Molecular Adsor-bent Recirculating System (MARS) is an extracorporeal Acute LiverFailure (AHF) support system method using albumin-enriched dialysate to facilitate the removal of albumin-bound toxins. Veno-venous access(double-lumen catheter type) was used for blood supply. Intravenousheparin was used for blood anticoagulation for the maintenance of theextracorporeal circuit. Blood flow rate was 150 250 mL/min, depending onthe hemodynamic situation of the patient. Blood passed through an albuminnon-permeable, high flux dialysis membrane. A closed-loop dialysate circuitcontaining 600 mL 10% stored human serum albumin (Dacrion) was drivenby a roller pump of the MARS monitor at 150 mL/min. The clinical improve-ment was evaluated primarily through Child Pugh Score, Model for End-stage of Liver Disease (MELD). In each patient, liver function (AST, GGT,total and direct bilirubin, coagulation, ammoniemia, albuminemia, serumbile acid), kidney function (creatinine, sodium, potassium, azotemia, diure-sis/h), arterial pressure were evaluated before and after the treatment.Before each treatment patients underwent to abdominal ultrasound or CTscanner to exclude organic causes for the pruritus. We have observed adecrease in total bilirubin, creatinine and bile acids together with a signifi-cant improvement in Visual Analog Scale (VAS) (pt 01 score from 10 to 1;pt 02 score form 10 to 0; pt 03 score from 10 to 4; pt 04 score fro 9 to 1;

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pt 05 score from 10 to 5; pt 06 score from 9 to 1. Due to the small numberof patients results are not statistically significant.

O 020 ATHEROSCLEROTIC MARKERS IN HEMODIALYSISPATIENTSP. Dejanov1, B. Dejanova2, G. Spasovski1. 1Clinic of Nephrology, MedicalFaculty, Skopje, 2Institute of Physiology, Medical Faculty, Skopje, Republicof MacedoniaBackground/Aim: Atherosclerotic changes are common in hemodialysis(HD) patients that have influence to their quality of life, morbidity and mor-tality. The aim of this study was to examine the biochemical parameters asatherosclerotic predictors in HD patients. Methods: A number of 76 patientswere divided in 3 groups related to HD duration: I group—less than 5 years(n = 26); II group—5–10 years (n = 22) and III group-more than 10 years (n = 28) going on HD. The following biochemical parameters were deter-mined: cholesterol, triglycerides, LDL, LDL-ox antibodies, HDL, lipid per-oxidation (MDA), and biological activity of von Willebrand factor. Theinfluence of different HD membranes were also examined related to ath-erosclerosis for MDA and for von Willebrand factor biological activity:cuprophane (n = 30); polymetiymetacrilat (n = 30); hemophane (24) andpolysulphone (n = 20). Routine methods for triglycerides, cholesterol, LDL,HDL were used (Merck, Germany). Enzyme immunoassay (Biomedicagruppe, Austria) was used for LDL-ox antibodies and for MDA, fluorimet-ric method with thiobarbituric acid; for von Willebrand factor combinationassay by Dade Behring, Germany. Results: For triglycerides increased levelwas found in the III group (2.90 ± 1 mmol/L) compared to I group (2.18 ±0.9 mmol/L) with statistical significance p < 0.05. Increased level of LDL-oxantibodies was also found in the III group, 356 ± 259 mU/mL (p < 0.05).Lipid peroxidation showed statistical significance of increased level from4.62 ± 0.8 in I group to 5.40 ± 01.0 mmol/L in III group (p < 0.05). Biologi-cal activity of von Willebrand factor was also increased (p < 0.05). Regard-ing different HD membranes, polymetylmetacrilat showed the highest levelof von Willebrand biological activity (p < 0.001) and the highest level ofMDA was found in hemophan membrane (p < 0.01). Therefore polysul-phone membrane was found to be the most appropriate one. Conclusion:The increased level of MDA and LDL-ox antibodies showed increasedoxidative stress in these patients. This accelerates impairment of cell mem-brane integrity and function, leading to foam cells proliferation in smoothmuscle cells of blood vessels. Hemodialysis membranes have also impact onatherosclerotic appearance. The results showed atherosclerotic accelerationin patients going on longer HD duration.

O 021 MONITORING OF THE METABOLIC CHANGES DURINGKETOACIDOSIS USING MICRODIALYSIS TECHNIQUE. A PRE-LIMINARY INVESTIGATIONA. Ciechanowska1, J. Krzymien2, S. Sabalinska1, J.M. Wojcicki1, P. Ladyzyn-ski1, A. Ehrmann2, G. Rosinski2, B. Ziolkowski2, E. Pulawska2, W. Karnafel2,J. Kawiak1. 1Center of Excellence ARTOG, Institute of Biocybernetics andBiomedical Engineering PAS, 2Clinic of Gastroenterology and MetabolicDiseases MA, Warsaw, PolandIntroduction: Microdialysis gives possibility of review what goes on in thetissue—before any chemical events are reflected in changes of systemicblood levels. Aim: The main objective of the project is to characterizepatient’s metabolic state in ketoacidosis during application of the standardtreatment by measurements of the biochemical parameters like glucose,lactate and glycerol, in the interstitial fluid. Materials and Methods: Basicmeasurements were performed during 48 hours with sampling every 20minutes. Preliminary investigations were carried out on 7 patients aged from23 to 76. Duration of diabetes was from 0 to 14 years and glycated hemo-globin HbA1c from 9.4 to 15.5%. The study group was very diversified in clinical and biochemical respect. In the admission individual patients pH was from 6.9 to 7.3, glycemia—18.0 to 45.9 mmol/l, sodium—125 to 140 mmol/l and potassium—3.5 to 8.4 mmol/l. Results: In almost all assessedcases glucose measurements performed after initialization of treatmenthave been found to be significantly lower in the interstitial fluid than in theblood compartment. Then, after initial hydration the levels of glycemia cor-related well with the reference measurements from blood. However, in onecase glycemic course in the interstitial fluid was lower during whole moni-toring period. In almost all patients level of the lactate in the interstitialfluid reflected measurements in the blood. However, in one patient the levelof this parameter was in the interstitial fluid much higher than in the blood.Assessing glycerol level, in all cases, lack of correlation between measure-

ments in the interstitial fluid and blood has been found. Conclusion: Furtheranalysis with higher number of patients is needed to make a full descrip-tion of the patient’s metabolic changes measured in the interstitial and theblood compartments. It can be stated that application of quasi–continuousmonitoring using microdialysis technique may create completely newquality in data acquisition and can lead to change of the current standardtreatment.

Symposium Artificial Liver

O 022 ALLOGENIC HEPATOCYTE TRANSPLANTATION WITH AMINIMALLY INVASIVE TECHNIQUE. EFFECT ON CRIGLERNAJJAR SYNDROME TYPE IG. Ambrosino1, S. Varotto1, S.C. Strom2, G. Guariso1, E. Franchin, D. Miotto,L. Caenazzo, P. Carraro, D. D’Amico, L. Zancan, L. D’Antiga. 1Universityof Padova—Padova Italy; 2University of Pittsburgh, Pittsburgh, PA USAIntroduction: Children with Crigler-Najjar syndrome type 1 (CN1) are atrisk for kernicterus, despite the use of phototherapy that becomes less effec-tive after the first few years of life. Orthotopic liver transplantation is cura-tive but precludes the benefits of gene therapy possibly available in thefuture. Aim: Our aim was to partially restore uridine diphosphoglucuronateglucuronosyltransferase activity in a child with CN1 by allogenic hepatocytetransplantation (AHT) performed with an inexpensive and minimally inva-sive technique. Methods: A 9 year-old boy with CN1 was prepared withplasmapheresis, transhepatic placement of a portal catheter, immunosup-pression with tacrolimus. When a segment of a graft was available, 7.5 ¥ 109hepatocytes were isolated and, after heparinization and administration of20 mg/kg of methylprednisolone to the patient, were infused into the portalvein while he was awake. Cardiac electrical activity, central venous pressure,portal pressure, invasive blood pressure and transcutaneous oxygen satura-tion were monitored. The child was then followed as a normal graft recipi-ent on a tacrolimus/prednisolone based immunosuppression. After twoweeks from AHT phenobarbitone was added to promote the enzymaticactivity of the transplanted hepatocytes. Nocturnal phototherapy was con-tinued throughout the studied period. All the procedures were carried outon light sedation/analgesia with midazolam and ketamine. Results: Hepa-tocyte infusion was carried out with no significant variation of vital signs.The child was watching the television with his mother during the cell infu-sion. Mean bilirubin level was 46 after AHT (t-test ± 38) before, and 359mmol/l SD ± 530 mmol/l (SD p < 0.001). There were no major complicationsduring the follow up after AHT. Conclusion: Allogenic hepatocyte trans-plantation performed with a minimally invasive technique is effective andsafe, and can be used as an alternative to orthotopic liver transplant in dis-eases such as Crigler-Najjar syndrome type 1.

O 023 FIRST RESULTS IN CONTINUOUS ALBUMIN VENO-VENOUS HAEMODIAFILTRATION IN ACUTE LIVER FAILURE(ALF) IN CHILDHOODH.I.G. Ringe*, M. Zimmering**,W. Luck***, I. Sauer****. *Pediatric Inten-sive Care Unit, **Department Pediatric Nephrology, ***Department Pae-diatric Gastroenterology, ****Department Experimental TransplantSurgery, Charité Campus Virchow, Berlin, GermanyIntroduction: ALF in childhood is a life threatening condition, which is onlysurvived by 40% of the patients without liver transplantation. In adults inauxiliary liver transplantation (LTX) revealed that the remaining recipientliver has the possibility to recover. Therefore artificial detoxification systemsto compensate liver malfunction have been developed. Whether they wereuseful and safe in childhood was unknown. Method: 7 children aged 4 to 13 years were treated for severe ALF of various origin between 2000–05.They underwent Continuous Albumin Veno-Venous Hemodiafiltration(CAVVH, Baxter 11/14Ò). Depending on their age and bodyweight High-Flux-Filter with a size of 70 S (98 ml) to 100 S (138 ml) were used. Theturnover rates for hemofiltration was 400–900 ml/h. Simultaneously hemodi-afiltration was applied. 4.5% albumin solution continuously flowed againststream at turnover rates similar to hemofiltration rates. Coagulation, bloodcell count, bilirubin, bile-acid, ammonium (NH3) and blood pressure (BP)were measured and hepatic encephalopathy (HE) score was taken. Results:After 10 hours bilirubin decreased in all patients below 10 mg/dl. NH3 andbile-acid levels were lowered to normal range. In 4 patients HE could be reduced by one to two degrees 2. Two patients with HE remainedunchanged. In one case HE deteriorated. In all patients BP remained stableor rose (n = 2) during the CAVVH. Fibrinogen rose in two patients. 5

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patients were bridged to LTX (2 auxiliary). One liver recovery occurredwithout LTX and 1 after auxiliary LTX. In one case treatment was with-drawn. Two patients died after LTX. Discussion: CAVVH reduces bilirubin,bile acid, NH3 and presumably other neurotoxic and toxic substances, asthere are glutamate, prostaglandin, endotoxin and other cytokines. Thisassumption was made with regards to our observed reduction in HE score(n = 4) and increase in BP (n = 2). Two children received an auxiliary LTX.In one the remaining liver recovered. It had rising fibrinogen prior to LTXand was similar to a child that recovered without re-LTX. This suggests thatrising fibrinogen might indicate liver recovery. No criteria have been foundto distinguish without doubts whether a patient with ALF might recover ornot. Conclusion: CAVVH in children seems to be effective in ALF for bridg-ing to LTX or replacement until liver recovery.

O 024 COMPARISON OF POWDERED AND GRANULARCARBONS FOR REGENERATION OF DIALYSATE AND FIL-TRATES IN HEPATIC FAILURES.R. Ash1,2,T.A. Sullivan1, D.J. Carr1. 1HemoCleanse, Inc., 2Arnett Clinic andDialysis Center, Lafayette, IN, USABackground/Aims: The selective chemical binding of sorbents is well suitedto regeneration of dialysate and protein-containing filtrates in treatment ofhepatic failure. Most sorbents are used in granular form in columns, butseveral machines have been developed to utilize powders or very fine par-ticles of sorbents (the BioLogic-DT, Sorbent Suspension Reactor or SSR,DTPF and the Microspheres Detoxification System). We performed in vitrostudies to compare binding of hepatic failure markers by powdered sorbentsand to compare results to granular sorbents. We also constructed full sizeversions of the SSR with 0.8 micron membrane and powdered charcoal anddetermined the ability to regenerate dialysate and protein solutions atvarious flow rates. Methods: In vitro Langmuir binding curves were deter-mined for powdered charcoal (Norit A) for the following compounds:creatinine, unconjugated bilirubin, cytokines, and various amino acids.Comparison studies were done performed on a high surface area granularcarbon (MaxSorb), on the same sorbent after grinding. Comparison datawas obtained from literature for a variety of carbons including fractalcarbons (HSGD, Dr. V. Nikolaev). Hydraulic and chemical binding tests ofthe Sorbent Suspension Reactor were performed at 450 ml/min dialysateflow, and at 100 ml/min flow of 5% albumin. Results: Powdered carbon hadsignificantly higher binding of unconjugated bilirubin than any granularcarbon, and higher than granular carbons after pulverization. Fractalcarbons had lower bilirubin binding than powder but better than other gran-ular carbons. Both powdered charcoal and fractal carbons showed highbinding for many cytokines. Amino acid binding by powders showed strongselectivity for aromatic amino-acids. The SSR functioned to regeneratedialysate at 450 ml/min without any loss of permeability. Regeneration of5% albumin solution proceeded at 100 ml/min but with sieving coefficientsof 60–80%, partly improved with backflushing. Conclusions: Powdered sor-bents have ideal chemical function for regeneration of dialysate in hepaticfailure treatments, but regeneration of protein solutions is problematic.Fractal carbons or similar sorbents may be preferable for regeneration ofprotein-containing filtrates.

O 025 THE MICROSPHERES-BASED DETOXIFICATION SYSTEMFOR EXTRACORPOREAL LIVER SUPPPORTV. Weber1, I. Linsberger1, J. Hartmann1, C. Schildböck1, A. Leistner2,D. Falkenhagen1. 1Center for Biomedical Technology and ChrisitianDoppler Laboratory for Specific Adsorption Technologies in Medicine,Danube University Krems, Austria, 2Polymerics GmbH, Berlin, GermanyBackground: The Microspheres-Based Detoxification System (MDS) rep-resents a highly flexible apheresis system with broad application potentialdepending on the specificity of the adsorbents used. The aim of this studywas the development of adsorbent microparticles for extracorporeal liversupport and their characterization in an experimental set-up of the MDS.Methods: Spherical microparticles for the selective binding of bilirubin andbile acids were obtained by co-polymerization of divinyl benzene with apolar monomer. Adsorption capacity and kinetics for bilirubin and cholicacid were tested in batch experiments as well as in an experimental set-upof the MDS using pools of human plasma (2.5 L) or blood (1 L) spiked with300 mmol/L bilirubin and 100 mmol/L cholic acid. The Albuflow filter (Fre-senius Medical Care) was used for plasma separation. Experiments wereperformed with 60 mL of adsorbent corresponding to an adsorbent con-centration of 20% (v/v) in the plasma circuit. Results: The average diame-

ter of the porous adsorbents was 14.7 mm (range: 1–45 mm). The adsorbentsurface as determined by nitrogen adsorption was 561 m2/g with a lowamount of micropores (26 m2/g), which are not accessible for albumin-boundtoxins. The adsorbents were biocompatible (no cytotoxicity, no release ofhaemolytic or cytokine-inducing substances) and showed no significantadsorption of proteins or heparin. In the experimental set-up of the MDS,both bilirubin and cholic acid were removed with excellent kinetics and highefficiency. After 15 and 360 min, respectively, 1.0 mmol and 4.2 mmol of cholicacid as well as 1.1 and 4.9 mmol of bilirubin was bound per mL of adsorbent(mean data from the plasma experiments; n = 3). Conclusions: In the exper-imental MDS set-up, efficient detoxification of a 2.5 L plasma pool could beachieved with 60 mL of adsorbent which corresponds to about 10% of theamount used in conventional liver support systems. The microparticlesdeveloped in this study combine excellent binding characteristics for toxinsrelated to liver failure with high biocompatibility and are well-suited for theapplication in the Microspheres-Based Detoxification System.

O 026 USE MARS IN DIFFERENT HEPATIC ETIOLOGY IN THEACUTE LIVER FAILUREG. Novelli, M. Rossi, M. Pretagostini, F. Pugliese, F. Ruberto, L. Novelli,F. Nudo, V. Morabito, A. Bussotti, S. Corradini, S. Martelli, P.B. Berloco.II Clinica Chirurgica Universita La Sapienza, Roma, ItalyThe various definitions of acute liver failure do not accurately reflect the dif-ferences in clinical evidence and in prognosis. Liver Support Devices toimprove clinical condition before LT in 17 patients with primary non func-tion, 30 by fulminant hepatitis, 24 were affected by delayed non function, 65by acute on chronic hepatic failure. The average age of these patients wasabout 41.8 years, and the average number of application with MolecularAdsorbents Recirculating System (MARS) was about 6 (range: 1–24), themean length of application instead was about 9 h (range: 8–20). MARS treat-ment was carried out in Acute Liver Failure (ALF) patients with continuousdialysate flow similar to Continuous Veno-Venous Hemofiltration (CVVH),albumin flow <20% of hematic flow, heparin 5/10 UI/Kg. In Acute-on-Chronic Hepatic Failure (AoCHF) patients 6 to 11 hour treatments werecarried out (average 8.5) for a minimum of 3 treatments. The majority ofpatients were treated in Intensive Care Unit (ICU). Laboratory results werealso monitored and showed progressive modification: bilirubin (before treat-ment 22.37 ± 11.6 mg/dl, after treatment 11.36 ± 7.5 mg/dl) and ammonium(before treatment 238.2 ± 19 mg/dl, after treatment 115.4 ± 12 mg/dl) showedsignificant change (p < 0.01). Lactates (before treatment 3.48 ± 1.3 mmol/L,after treatment 1.76 ± 1.1 mmol/L) and creatinine (before treatment 2.36 ±0.18 mg/dl, after treatment 1.26 ± 0.67 mg/dl) also showed significant change(p < 0.02 and p < 0.04). Glasgow Coma Score (GCS) went from 8.6 ± 1.4 to 11.9 ± 3.9 (p < 0.05). A mean middle celebral artery flow (V media) wentfrom 46 cm/sec/26–59) to 73 cm/sec (52–106) showing a decrease in cele-bral edema. However these differences were not significant. InternationalNormal Ratio (INR) scores (before treatment 2.4 after treatment 1.8) alsoshowed no significant change. The MARS can be applied with tolerability forlong period. It can be used in patients with Delayed Non Function (DNF)and Fulminant Hepatitis (FH) as a bridge to transplant. In patients withDNF it’s used for waiting to complete recovery of the transplanted organ.Therefore MARS can also limit the necessity to carry out further transplants.

O 027 ARTIFICIAL LIVER SUPPORT SYSTEMS—A MEDICALAND HEALTH ECONOMIC HTA-REPORTF. Hessel*, K. Grabein*, U. Siebert+, P. Schnell-Inderst*, J. Wasem*. *Insti-tute for Health Care Management, University of Duisburg-Essen, Germany,+MGH Institute for Technology Assessment, Harvard Medical School,Boston, MA, USARationale: Artificial liver support systems (ALS) or liver dialysis is a newtherapeutic approach for patients with acute liver failure (ALF) or acute-on-chronic liver failure (ACLF). Using this technology patients should havea better chance for regaining their own liver function or for successful bridg-ing to liver transplantation. Since 2004 artificial liver support systems arereimbursed in Germany. The treatment costs are 10–15,000 EUR perpatient. Objectives: This health technology assessment report has the objec-tive to determine and summarize the scientific evidence on the medical effi-cacy and the economic effectiveness of the use of ALS in patients with ALFor ACLF. Methodology: In an extensive systematic literature search in allrelevant medical and economic data bases all published studies on ALSwere identified and systematically described. All results concerning thetreatment of ALF or ACLF were extracted and if possible synthesized to

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final recommendations on the use of ALF. Results: Three different artificialliver support systems could be identified. For the first system (BioLogic DT)neither of the identified studies reported medical or economic benefits. Forthe second system (Prometheus) no randomized controlled studies report-ing medical or economic effects are available yet. For the third system(MARS) for patients with ACLF a significant improvement of clinical para-meter and 30d-survival could be demonstrated. First health economicstudies with a very short time horizon report costs per QALY of 60,000EUR and conclude that prolonging the time horizon would improve cost-effectiveness. All studies show methodological limitations, especially con-cerning the sample size and the time horizon. Conclusion: The presentscientific evidence according to published trials on ALS does not show anymedical or economic benefit of the liver support systems BioLogic DT andPrometheus. The limited evidence for the system MARS gives hints thatACLF patients might clinically benefit from the use and that cost-effec-tiveness is acceptable. Future randomized controlled studies with largesample size and health economic models to estimate long term benefits arenecessary to confirm these results.

Modeling and Simulation

O 028 CFD ANALYSIS OF DIFFERENT BEARING GEOMETRYVARIATIONS OF THE ARROW CORAIDE LVADM. Hormes,A. Arvand, U. Horst,A. Brandt, U. Steinseifer,T. Schmitz-Rode.Helmholtz-Institute of Biomedical Engineering, Chair of Applied MedicalEngineering, University Aachen, GermanyBackground: The CorAide LVAD was developed at the Cleveland ClinicFoundation (CCF) for long term applications. Inside the CorAide, a rotat-ing impeller spins around a stator assembly. The arrangement of the rotorand the stator results in a lubricated fluid film journal bearing. Differentgeometry variations of the journal bearing have been analysed by means ofCFD. Methods: Based on a hexahedral mesh the CFD simulations havebeen performed and successfully validated by the comparison of experi-mental and numerical H-Q curves for different operating points. Due to thedifferent flow behaviours of the whole pump (WP) and the journal bearing(JB) these two regions had to be solved separately. As boundary conditionsfor the laminar JB simulation, the pressure distribution of the turbulent WPsimulation at the JB inlet and JB outlet have been set. Different geometryvariations of the JB regarding the rotor inner diameter, gap size and theangular positions of the rotor/stator have been analysed. Results: Differ-ent geometry variations of the JB have an impact on the hydraulic andhemolytic properties of the pump. Hence, a optimal geometry of the journalbearing and the exact rotor stator position of the pump can be determined.Conclusion: By means of CFD the flow behaviours, the hydraulic andhemolytic properties of the very small fluid film journal bearing could beanalysed and consequences resulting from new design improvements couldbe predicted.

O 029 TIME RESOLVED PIV FLOW FIELD STUDY OF THE BI-LEAFLET AND MONO-LEAFLET MITRAL VALVEST. Akutsu, T. f*ckuda, J. Saito. Dept. of Mech. Engineering, Kanto GakuinUniversity of Yokohama, Yokohama, JapanBackground: Fluid stresses are considered influential to the cause of hemol-ysis and thromboembolic complications. Experimental study was conductedto analyze the influence of the prosthetic heart valve designs on the flowfield using time resolved PIV system. Models and Method: Two bi-leafletvalves, the St. Jude Medical (SJM) valve with straight leaflets and the Jyros(JR) valve with curved leaflets, and two mono-leaflet valves, the Medtronic-Hall (MH) valve with straight leaflet and the Bjork-Shiley monostrut (BS)with curved leaflet, were tested in the mitral position under pulsatile-flowcondition. A sophisticated cardiac simulator in conjunction with timeresolved PIV system was used to investigate the influence of the valvedesign differences of each valve on the flow field. Results: Based on theexperimental results obtained for the bi-leaflet and mono-leaflet valves, fol-lowing general statements can be made. All valves (The SJM, JR, MH, andBS) showed distinct sideway flows immediately after the valve was opened.The small differences in hinge location and leaflet configuration in the bi-leaflet configuration generated noticeable differences on the flow, particu-larly during the opening and accelerating flow phase of the valve. Straightleaflet of the SJM valve did not deflect the flow when it fully opened, whilecurved leaflet of the Jyros valve deflected the flow sideway even the valvewas fully opened. The SJM valve generated central downward flow while

the JR valve generated central upward twin circulatory flow. Mono-leafletvalves generated drastically different flow field when valve orientation waschanged. Both valve generated simple circulatory flow field at posterior ori-entation. Similar to the bi-leaflet valve, straight leaflet of the MH valve didnot deflect the flow too much, while curved leaflet of the BS valve deflectedthe flow dramatically sideway even the valve was fully opened. Conclusions:The small differences in leaflet configuration in the bi-leaflet and mono-leaflet valves generate noticeable differences on the flow, thus affectingoverall hemodynamic performance.

O 030 DEVELOPMENT AND VERIFICATION OF VENTRICLE-SHAPED CHAMBERS FOR THE DLR ASSIST DEVICET. Schmid1, M. Stock2, S. Donisi4, W. Schiller3, D. Liepsch2, B. Laschka2,G. Hirzinger1, A. Welz3, H. Oertel4. 1Institute of Robotic Systems, GermanAerospace Center (DLR), 2Chair of Fluid Mechanics, Technical UniversityMunich, 3Heart Surgery Clinic, University of Bonn, 4Institute of FluidMechanics, University of Karlsruhe (TH), GermanyAim: In order to minimize the risk of thrombo-embolism, two types of ven-tricle-shaped pump chambers are to be developed. The chambers shouldprovide a velocity distribution similar to the human left ventricle andimprove the total efficiency of the assist device. Methods: To verify thequality of the chambers, flow visualisation with birifringend fluid and flowmeasurements with Particle Image Velocimetry and a bloodlike non-New-tonian model fluid were carried out. The chambers were compressed witha rigid pusher plate and, in a second experiment, with a hydraulic fluid. 3D-shear stress, vorticity and 3D-pathlines were calculated (Resolution:1.3 mm). Numerical flow simulation with moving boundaries was used tomodify the chamber’s geometry. Acute animal studies (pigs, n = 3) werecarried out to verify the results. Results: During filling phase, two recircu-lation zones similar to those found in the human left ventricle can beobserved, in which one rises to a dominant vortex. The degree of circula-tion inside this main vortex is significantly lower then in formerly used pumpchambers. Especially at high frequencies, the pump flow could be increasedfrom 2 l/min to 3.4 l/min, the total efficiency of the VAD from 19% to 31%.The movement of the pusher plate generates flow separation at the bottomof the chamber. During animal studies, a tendency of clots could beobserved in this region. Increased shear rates up to 1500 1/s were observedat the front of the pusher plate and downstream the inflow valve duringfilling phase. Particles are washed out at the latest of two pump cycles. Con-clusion(s): A nearly physiological flow field can be generated in the ventri-cle-shaped chamber. The improved routing of the incoming fluid clearlyincreases the hydraulic efficiency. On base of the experiments, the charac-teristic number “degree of circulation” was defined to characterize the effi-ciency of pump chambers. The disturbance of the rigid pusher plate issignificant during filling phase. It leads to less intensive vortex formationand low shear rates at the bottom.

O 031 COMPARISON STUDY ON ELASTIC PROPERTIES OF LUNGS: THE ADDED COMPLIANCE AND THE END-INSPIRATORY METHODSK.J. Palko1, M. Kozarski1, M. Darowski1, A. Rogalski1, A. Tokarz1. 1Instituteof Biocybernetics and Biomedical Engineering, Polish Academy of Sciences,Centre of Excellence ARTOG, Warsaw, PolandBackground/Aim: Measurement of elastic properties of lungs during theartificial ventilation especially under pathological conditions is of the firstimportance for the anaesthesiologists. The aim of the presented work wasto check a possibility of using the “added compliance method” in the clinics.Methods: Elaborated method of the measurement of basic mechanical para-meters of lungs was based on the RC model which is sufficient to estimatesuch parameters as the total compliance (representing their elastic proper-ties) and the total airway resistance. This method was compared to the end-inspiratory method while using the same experimental set-up. Additionally,the compliances of the model of lungs and the extra-added pneumaticcapacitances were estimated experimentally with the calibrated syringe andthe pressure sensor connected to the computer system to register the results.The computer system was also used to control the valves and to calculatethe results of the measurements. Results: Very promising results wereobtained during the study. The relative error of the measured complianceof the lungs’ model was estimated in two different cases of the measure-ment system: for airtight—leak proof (1%) and untight system (8%). Con-clusion(s): The study of the “added compliance method” indicated somepossibilities to use this method in clinics so the continuation of the study is

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needed. There is a possibility to apply the studied method in diagnostic testshowever patients’ cooperation with the medical staff would be necessary.This work was supported by a grant no. 3 T11E 008 28 from the Ministry ofScientific and Information Technology, Warsaw, Poland.

Dialysis

O 032 THIXOTROPIC CATHETER LOCKING SOLUTION DOESNOT SPILL DURING INJECTION AND REMAINS IN THECATHETERHans-Dietrich Polaschegg. Medical Devices Consultant, Köstenberg,AustriaBackground: Atrial catheters for blood access are filled with a locking solu-tion between treatments. Up to 20% of the solution spills out at when anamount equal to the filling volume is injected. This is followed by gravitydriven spillage if the locking solution density is different from blood density.This may lead to bleeding in sensitive patients but also result in clotting ofthe catheter tip. Both effects have been reported by the author at last year’sconference. Thixotropic hydrogel was tested as lock solution in a settingcomparable to the tests previously reported. In addition, basic safety aspectsunder the condition of user error (injection of the hydrogel) are addressed.Materials: Water. Cosmetic hydrogel. Food colour. PVC tubing with 2 mminner diameter mimicking a catheter. Methods: In-vitro experiments. 1.Visual observation of exchange of colourised gel-lock solution with differ-ent densities with water. 2. Quantitative measurement of the spillage ofcolourised locking solution over several hours with the help of a fibre-opticspectrophotometer and an immersion probe. Gel-lock was injected into abeaker filled with water and upstream of a 5 mm filter (mimicking lung cap-illaries) positioned in a loop operated with water. The temporary pressureincrease in front of the filter caused by this “embolisation” was recorded.Results: Gel-lock does not spill out when an amount equal to the fillingvolume is injected. It remains in the catheter and dissolves very slowly atthe tip. When injected into a fluid circuit upstream of a 5 mm filter it dis-solves within a few minutes. Conclusions: 1. Lock-solution spillage can beavoided by using thixotropic hydrogels. 2. Gel-lock injected by user errorwill dissolve rapidly in the blood stream.

O 033 EFFECT OF SUPER-FLUX CELLULOSE TRIACETATEDIALYZERS WITH LARGE PORES ON REMOVAL AND CLEAR-ANCE OF UREMIC SOLUTESR. De Smet1, A. Dhondt1, F. Galli2, S. Eloot3, M.A. Waterloos1, N. Lameire1,R. Vanholder1. 1Nephrology, University Hospital Gent, Gent, Belgium,2Internal Medicine, University of Perugia, Perugia, Italy, 3Laboratory ofHydraulics, University Gent, Belgium.Aim: Uremic solutes accumulate in ESRD-patients and interfere with bio-chemical functions. Low-flux (LF) hemodialysis (HD) is ineffective in low-ering all uremic compounds, especially protein bound. We consideredwhether super-flux (SF) cellulose triacetate membranes (CTA) withextremely large pores result in a better removal and clearance of uremicsolutes with different molecular weight (MW) and protein binding.Methods: Eleven ESRD-patients received consecutively HD with LF andSF CTA during 3 weeks. Dialysate flow, blood flow and ultrafiltration ratewere the same during all sessions. At the end of each period dialysate, pre-HD and post-HD blood were collected. The concentration of 9 uremic com-pounds was determined: urea (UR), creatinine (CR), uric acid (UA) for thenon-protein bound (non-PB), 3-carboxy-4-methyl-5-propyl-2-furanpropi-onic acid (CMPF), indole-3-acetic acid (IAA), indoxyl sulphate (IS), hip-puric acid (HA), pentosidine (PE) for the protein bound (PB) and low-MWAGE-peptides (AGEs). Reduction rate (RR), dialytic clearance (Dcl) andmass transfer-area coefficient (KoA) were calculated. Results: SF HDresulted in a significantly better RR for IS and AGEs and correlations ofRR were observed for UR with HA (r = 0.59), IS (r = 0.68), and IAA (r =0.67), (P < 0.05). Protein binding increased after LF as well as after SF HD.Dcl ranged from 20 ± 5 to 179 ± 20 mL/min for LF and from 24 ± 6 to 191 ± 24 mL/min for SF; a significant increase with SF of Dcl was found forUA, HA, IS (P < 0.05) and a trend was observed for AGEs (P = 0.090). KoAenhanced for most compounds and was relatively more important for PB-compounds and AGEs. A univariate analysis revealed that MW, proteinbinding and membrane type (pore size) tended to determine KoA (P =0.068). Conclusions: SF-CTA was moderately superior to LF-CTA in con-ventional HD setting with SF-CTA: 1) RR was enhanced, PB solutes behavemore as easy to remove non-PB solutes 2) Dcl improved for more com-

pounds in the PB group and AGEs compared to non-PB group 3) KoAincreased relatively more for PB solutes and AGEs and 4) KoA dependedof MW, protein binding and membrane pore size.

O 034 HEMODIAFILTRATION WITH SELF-DILUTIONK. Lee1,4,5, J.H. Jeong1,4,5, C.H. Mun1,4,5, J.H. Kim1,4, B.G. Min2,3,4,5. 1Interdis-ciplinary Program in Biomedical Engineering Major, Seoul National Uni-versity, 2Department of Biomedical Engineering, College of Medicine, SeoulNational University, 3Institute of Medical Engineering, Medical ResearchCenter, Seoul National University, 4Korea Artificial Organ Center, 5CancerResearch Institute, Seoul National University Hospital, Seoul, KoreaAim: The mortality due to the retention of mid-size molecules during renalreplacement therapy can be reduced by HDF. The ex-vivo and in-vivoresults of HDF with self-dilution using a multifunctional dialyzer (MFD)which was developed in the lab are described in the paper. Self-dilutionmeans there is no external on-line dilution during HDF. Methods: The MFDis composed of two independent flow paths for dialysate, which means thatthe dialysate pressure can be regulated independently in each part. Apply-ing pulsatile pump, positive pressure in one part of dialysate and negativepressure in another part were generated, while mean blood pressurethrough the MFD was maintained around zero. Therefore, both ultrafiltra-tion (UF) and back-filtration (BF) occurred simultaneously in a single dialyzer. Results: When TMP for UF and BF were 24 and -39 mmHg respectively in ex-vivo test, 200 (ml/min) of UF and 194 (ml/min) of BF wereachieved at the same time. Therefore, net volume removal rate from bloodwas 6 (ml/min). In addition, higher mid-size molecular clearance was con-firmed in the in-vivo test due to the higher UF rate than conventionalhemodialysis. Conclusion: Using a domestically designed new dialyzer, HDFwith no dilution and better physiologic conditions were achieved. Besides,the HDF with self-dilution is believed to be one of the clinical protocols forRRT.

O 035 HEMOFILTRATION SYSTEM WITH NON OCCLUSIVE PULSATILE PUMPD. Rodríguez-Martínez, I. Berenguer, S. Salom, J.F. Del Cañizo. Unidad deMedicina y Cirugía Experimental. Hospital General Universitario “Grego-rio Marañón”, Madrid, SpainAim: an hemofiltration system in which the roller pump has been replacedby a tubular non-occlusive vacuum-driven pump has been used in minipigsto test hemofiltration efficiency. Use of pulsatile pump offers advantagesover the classic ones. The size and priming volume are lower, and it couldbe placed close the patient shortening patient’s lines. The system designallows use of a postfilter valve without cause the system destruction. Thisvalve goes to increase transmembrane pressure and ultrafiltrate. The pul-satile pump prevents blood trauma compared with continuous roller pumps.Methods: hemofiltration procedures were established in minipigs (30–40 Kg). Filter was use during 4 procedures, in order to evaluate filtrationcapacity of the hemofilter (Minifilter Plus). Closing time of postfilter valvewas changed every 15 minutes during 120. Flows and pressures are acquiresand processed by means of a computerised system. Blood and ultrafiltratesamples are taking every 15 minutes. External jugular vein was catheterisedwith a double line cannula to connect system lines. Results: our results showthat ultrafiltrate volume increases if closing time of postfilter valve increasestoo, regardless of filter uses. Filtration capacity of the filter decreases withtime. Blood and liquid hemofiltration samples don’t show any significantlydifference. Conclusions: use of postfilter valve rises significantly ultrafiltraterate without flow increase. This fact permit achieve same hemofiltrationrates with lower flow.

Promising Concepts

O 036 ARTIFICIAL ELECTRONIC NOSE IS ABLE TO DETECTAND DISCRIMINATE BACTERIAL SPECIES BY THEIR SMELLR. Pregla1, F. Loke2, E. Damm1, W.R. Heizmann3, Zvi Boger4, R. Hetzer1.1Deutsches Herzzentrum Berlin, Berlin, Germany, 2Stanford University,Stanford, CA, USA 3Laborzentrum Berlin, Berlin, Germany, 4OptimalNeural Informatics, Rockville, MD, USABackground/Aim: Although “artificial organs” usually conjures up the ideaof artificial hearts, kidneys, livers etc., during the past 15 years chemosen-sors have been developed that, combined with artificial neural networks(ANN), are able to simulate the human sense of smell. We aimed to exploreone aspect of their use. A leading cause of mortality in mechanically venti-

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lated patients is pulmonary infections. We hypothesized that the smell ofpatients’ breath contains all information necessary to identify pulmonarypathogens using electronic nose (EN) technology. Methods: Firstly 10 bac-terial species were tested in pure culture on blood agar plates. Volatileorganic compounds were obtained by headspace-sampling with a Sam G3electronic nose (RST, Rostock, Germany) employing 10 metal oxide sensors(MOS). The resulting analyzable data series (1350) were fed into an elec-tronic network and evaluated. Secondly 183 breath samples collected from57 patients on consecutive days were analyzed. The EN data were pre-processed for ANN training by zero centering and unit scaling. ANNs with4, 5 and 6 hidden neurons were trained. Results: The in-vitro tests with purebacterial cultures provided reliable discrimination of the bacteria used witherror rates of less than 2%. Results were recognized within the first 20seconds of measurement. Evaluation of the patient samples indicates thatthe best results were obtained with models using 6 hidden neurons. The mostprevalent species were Enterobacter, Enterococcus and coag. neg. Staphy-lococcus with error rates of less than 9%. Even better results were obtainedusing “infected” and “non-infected” as only 2 outputs, resulting in error ratesof less than 3%. Conclusion: With the electronic nose a new artificial organis on the horizon with enormous potential for medical use as a noninvasivediagnostic tool. Although the experimental set-up and ANN training are stillcomplex, online monitoring of the smell of a patient’s breath may poten-tially give the attending physician a quick indication of the type of bacter-ial infection before the results of time-consuming laboratory tests areavailable.

O 037 INTERVERTEBRAL DISK TISSUE ENGINEERING: INFLU-ENCE OF DONOR PATHOLOGY ON CELL CULTURE RESULTSC. Eder1, R. Bartl2, J. Meissner2, M. Mickel3, H. Schöffl1, E. Falkner4,M. Ogon2. 1BioMed-Society for the Promotion of Biomedical and MedicalTechnological Research in Upper Austria, Linz, 2Orthopaedic HostpitalVienna, Speisin, Vienna, 3Carl Landsteiner Institute for Applied Cardiovas-cular Research, Vienna, 4Core Unit for Biomedical Research, Medical Uni-versity Vienna, Vienna, AustriaIntroduction: Disk degeneration is a common cause of low back pain. Tissueengineering has shown promising results regarding cartilage repair andregeneration. Aim of the presented study was to analyze the influence ofdonor pathology on cell culture results. Materials & Methods: Tissue samplesfrom patients undergoing surgery because of degenerative spine diseases orkyphotic/scoliotic changes of the spine were analyzed. Cells were harvestedby tissue digestion in 0,15% Collagenase Type II and cultured in DMEM sup-plemented with 10% FCS and 0,05 mg/ml Ascorbic Acid. Cell yield per gtissue was calculated and cell viability was determined. Cell proliferation wasanalyzed and histological characterization was performed from the originaltissue, during monolayer expansion and after three-dimensional spheroidculture. Results: Average cell yield was 13,77 ¥ 104 per g tissue after isolationof tissue deriving from patients under 18 years old and 35,150 ¥ 104 per gwhen isolating cells from older donors (p < 0,008). Mean viability was 96% inboth groups Cells deriving from degenerative spines started to proliferateimmediately after seeding while cells deriving from scoliotic spines needed alonger recovery period, but showed good proliferation features afterwards.Viability remained stable during monolayer culture and was above 95%during monolayer expansion. Histological analysis of native tissue did notreveal any significant pathology related differences. In contrast, cell culturesderiving from degenerative disks showed higher levels of Alcian Blue stain-ing, Safranin O staining (p < 0,006) and Azan staining (p < 0,001) thansamples deriving from scoliotic or kyphotic spines. Conclusions: Culture via-bilities and proliferation rates are similar and seem independent from patientage or pathology, but histological characteristics of cell cultures are different.Donor pathology should therefore be taken into account when planningintervertebral disk regeneration using tissue engineering techniques.

O 038 REGENERATION OF CANINE TRACHEAL CARTILAGEBY SLOW RELEASE OF GROWTH FACTOR FROM GELATINSPONGEY. Yamamoto1, H. Igai1, M. Gotoh1, Y. Tabata2, H. Yokomise1. 1Second Dep.Surg., Faculty of Med., Kagawa Univ., 2Institute for Frontier Medical Sciences, Kyoto University, JapanWe focused on inducing regeneration of the trachea to produce an artificialprosthesis. The first step in our attempt to produce an artificial trachea wasto induce regeneration of the tracheal cartilage. Objectives: We investigatedthe efficiency of basic fibroblast growth factor (b-FGF) or bone morpho-

genetic protein-2 (BMP-2) released from gelatin sponge in the regenerationof tracheal cartilage. Methods: A 1-cm gap was made in the mid-ventralportion of each of 10 consecutive cervical tracheal cartilages (rings 4 to 13)in 20 experimental dogs. In the control group (n = 5), the resulting gap wasleft blank. In the gelatin group (n = 5), gelatin sponge alone was implantedin the gap. In the b-FGF group (n = 5), gelatin sponge containing 100 mg b-FGF solution was implanted in the gap. In the BMP-2 group (n = 5), gelatinsponge containing 100 mg BMP-2 solution was implanted in the gap.We euthanized one of the 5 dogs in each group at 1, 3 and 6 months afterimplantation and examined the implant sites macro- and microscopically.RESULTS: In the control and gelatin groups, no regenerated cartilage wasobserved in the tracheal cartilage gap at 1, 3 and 6 months. The distancesbetween the cartilage stumps had shrunk. In the b-FGF group, fibrous car-tilage had started to regenerate from both host cartilage stumps at 1 month.At 3 and 6 months, regenerated fibrous cartilage filled the gap and had con-nected each of the stumps. The regenerated cartilage was covered withregenerated perichondrium originating from the host perichondrium. In theBMP-2 group, fibrous cartilage regenerated from both host cartilage stumpsat 1 month. The gap was filled with newly formed bone. At 3 and 6 months,newly formed bone filled the gap and had connected each of the stumpswhich was covered with regenerated fibrous cartilage. Shrinkage of the dis-tance between the host cartilage stumps was prevented in the b-FGF andthe BMP-2 groups. Conclusions: We succeeded in inducing cartilage regen-eration by using the slow release of b-FGF from a gelatin sponge, and theslow release of BMP-2 from a gelatin sponge induced the nascent bone inthe gaps in canine tracheal cartilage rings.

O 039 EXPERIMENTAL STUDY ON IN SITU TISSUE ENGINEER-ING OF THE BILE DUCT IN A CANINE MODELS. Nakashima1, T. Nakamura2, T. Yoshikawa1, S. Kin1, Y. Kuriu1, Y. Nakase1,C. Sakakura1, E. Otsuji1, A. Hagiwara1, H. Yamagishi1. 1Department ofSurgery, Division of Digestive Surgery, Kyoto Prefectural University ofMedicine, 2Department of Bioartificial Organs, Institute for FrontierMedical Sciences, Kyoto University, Kyoto, JapanBackground/Aim: Several attempts have been made in the past to replacebiliary defects with a variety of artificial materials. However, these havefailed mostly because of varying degrees of cholangitis, encrustration ofbiliary crystals, cicatrisation, and stricture formation. Therefore, we havedesigned a new type of artificial bile duct that supports host tissue regen-eration. The aim of this study is to evaluate the feasibility of using this pros-thesis as a scaffold for bile duct tissue regeneration in a canine model.Methods: Our prosthesis is composed of collagen sponge made fromporcine dermal collagen, and is reinforced with a polypropylene cylinder inorder to help overcome problems of stenosis of the prosthesis lumen. Thecommon bile duct of three beagle dogs weighing 8–10 kg was surgicallyresected (2-cm length) and then reconstructed using our prosthesis. Abiliary stent was placed on the common bile duct to prevent biliary leakageduring the initial stage of implantation. The stent was removed 2 weeks postoperation. The animals were sacrificed 3 months post surgery. Prior to this,cholangiograms were performed, and the bile duct was examined histolog-ically. Results: All three dogs survived up to the time of sacrifice—3 months.On examining the cholangiograms, there was no luminal narrowing or stric-ture formation, and contrast passed freely into the duodenum. The pros-thesis was infiltrated by the surrounding tissue and completely incorporatedby the body. Histological examination showed that tight connective tissue,including capillaries, had invaded the mesh pores. Formation of biliaryepithelium that lined the prosthesis lumen was observed to varying degrees;however, the center of the regenerated bile duct had not become reepithe-lized. Conclusions: Our prosthesis has high biocompatiblity for regen-eration of bile duct tissue in a canine model. The internal surface of theregenerated bile duct might be completely covered with biliary epitheliumin long-term survivors.

O 040 IN VITRO ANALYSIS OF APPPA MICROCAPSULES FORORAL DELIVERY: IMPACT OF MICROCAPSULES ON GI MODELFLORAF. Afkhami1, W. Ouyang, H. Chen, J. Bhathena, T. Halim, S. Prakash1. Bio-medical Technology and Cell Therapy Research Laboratory, Dept. of Bio-medical Engineering and Artificial Cells and Organs Research Centre,Faculty of Medicine, McGill University, Montreal, QC, CanadaBackground: A new membrane has been recently designed for the oraldelivery of therapeutic products; however, it has not been characterized yet.

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This study investigates the effects of the novel microcapsule on gastroin-testinal (GI) model flora and is compared with the commonly used mem-brane, alginate-poly-L-lysine-alginate (APA) for use in oral delivery.Methods: Novel APPPA microcapsules were prepared using alginate, poly-L-lysine and pectin. APPPA microcapsules were then exposed to variousGI fluids in a computer controlled in-vitro human G I model. Samples fromeach vessel analyzed by plating and formed colonies were enumerated andcompared with those obtained by plating control sample fluids. Enzymes b-galactosidase, b-glucosidase, b-glucuronidase, a-galactosidase and a-glu-cosidase were determined using spectrophotometer and UV absorbance 405 nm against a calibration curve of p-nitrophenol concentrations. Resultswere analyzed and compared with APA microcapsules formulation. Results:The impact on bacterial APPPA microcapsule on total GI microbial popu-lation; total anaerobic, total aerobic, Escherichia coli, Lactobacillus sp. andStaphylococcus sp. in each vessel was analyzed. Result shows that the pres-ence of APPPA microcapsules in the GI model does not significantly lessenthe bacterial population. Enzymatic analyses result shows no significant differences between APPPA and APA microcapsules. However, furtherinvestigations including in-vivo testing in experimental animal models arerequired. Details of these results will be discussed. Conclusion: The APPPAmicrocapsules have no significant impact on GI microbial flora making itsuitable for use in oral delivery applications. However, further research isrequired.

O 041 BLOCKED “STAR VECTOR” FOR IN VIVO GENE DELIVERYY. Zhou, Y. Nakayama. Department of Bioengineering, National Cardio-vascular Center Research Institute, Osaka, JapanBackground: The cationic polymers, which can generate nano-particles byformation of polyion complexes “polyplexes” with DNA irrespective of itssize and kind, are highly expected as one of the major non-vial vectors.However, the primary obstacle toward implementing an effective genetherapy using the cationic polymers remains their relatively inefficient geneexpression in vivo and in vitro, compared with virus vectors. Recently,we developed nano-structured hyperbranched cationic polymers, calledSTAR VECTORs, for a novel gene delivery non-viral vector. The STARVECTORs had high in vitro gene transfer activity. In this study, nano-struc-tured 4-branched, block STAR VECTOR was molecularly designed for anin vivo gene delivery. The in vitro gene expression levels of the vector andcommercially available cationic polymer vector (Exgene 500) were com-pared. In addition, in vivo transfection ability by STAR VECTOR wasexamined by measuring the lacZ expression activity in tissues of mice.Materials and Methods: The block STAR VECTOR was synthesized byiniferter-based photo-living radical block copolymerization of N,N-dimethy-lacrylamide at all terminals of the 4-branched cationic star polymer, whichwas synthesized by the similar polymerization of N,N-dimethylamino-propylacrylamide from tetrakis(N,N-diethyldithiocarbamylmethyl) ben-zene. Results: The blocked STAR VECTOR could form polyplexes by only mixing with pDNA (pGL3-control plasmid) under C/A ratio of 5. Thegene expression, examined using the luciferase activity, extremely increasedby blocking. The expression level was about several fold higher than thatwith Exgene 500. The cytotoxicity of the VECTOR was hardly detected ata C/A ratio less than 5. The VECTOR-based polyplexes (pDNA 25 mg) wereinjected to mice from jugular vein. At 48 hr after treatment, a higher levelof gene expression of b-galactosidase (lac Z) was observed in almost allorgans including liver, kidney or spleen. Conclusion: The blocked STARVECTOR is a new gene delivery polymeric vector with lower cytotoxicityand higher performance. Compared with the previously reported nonviralvectors, which were mainly used to deliver pDNA in vitro, the advantage ofour polyplexes makes them promising new agents for gene therapy in thenear future.

O 042 REGENERATIVE THERAPY FOR ISCHEMIC LIMBS BYIMPLANTATION OF CD34(+) CELLSA. Kawamura, T. Horie, I. Tsuda, K. Kukita, J. Meguro, M. Yonekawa. Sur-gical Dept. of Sapporo Hokuyu Hospital, Sapporo, JapanBackground: Rescue of ischemic limbs is either through surgery or med-ication is very difficult. Therefore, since 2001, we have performed regener-ative therapy by implanting of autologous CD34(+) cells. Methods:Ninety-two patients (25–85 yrs, male 61 : female 31) with ischemic limbs dueto mainly diabetic, ASO and maintenance dialysis were treated by trans-plantation of peripheral blood stem cell (PBSC). The PBSC suspension was

separated by apheresis technique. The detected mean CD34(+) cell numberwas 3.3 ¥ 107(M.). The suspension volume was about 60 mL and the cellswere implanted 60 to 130 points into the muscles of the ischemic limbs. Eachinjection volume was 0.5–1.0 mL. Four days prior to PBSC collection,G-CSF (Granulocyte Colony Stimulate Factor) was administrated at 5mg/kg/day for stem cell mobilization to peripheral blood. Separated cell wasimplanted without any treatment. Before and after implantation, ther-mography, plethysmography, 3D-CT and RI angiography were examined.Results: In thermography, priop to implantation, 28 limbs were a worm-redcolor and 64 were cold-blue. After implantation, 65% of the limbs becamered. In plethysmography, pulse-wave was observed in 23% cases prior toimplantation. After implantation, it was 43%. In 3D-CT, vessels were shownin 7% (6 cases), and they increased to 34% post implantation. Amputationand necrotmy was necessary in 38% of cases (35/92). Most of 35 cases waswith partial necrosis of the ischemic limbs. Conclusions: Although the effi-cacy of bone marrow implantation as a means of vascular regeneration hasbeen proved. However, it is clear the bone marrow collection is occasion-ally troublesome. The method, we have developed for the implantation ofCD34(+) cells from peripheral blood by apheresis as a means for vascularregeneration is very easy and safe. Also, its efficacy is comparable to implan-tation of bone marrow.

Heart Pumps

O 043 A MECHANICALLY NON-CONTACT AXIAL FLOW BLOODPUMPY. Mitamura1, K. Kido2, T. Yano3, D. Sakota1, N. Takahashi1, M. Kitamura1.1Hokkaido University, Sapporo, 2Tokyo Medical and Dental University,Tokyo, 3Akita Prefectural University, Honjo, Akita, JapanAim: To overcome the drive shaft seal and bearing problem a hydrodynamicbearing, a magnetic fluid seal and a brushless DC motor were employed inan axial flow pump. This enabled contact free rotation of the impellerwithout material wears. Methods: The impeller was directly connected to amotor rotor shaft. A hydrodynamic bearing was installed on the motor shaft.The motor and the hydrodynamic bearing were housed in a cylindricalmotor casing and were waterproofed by a magnetic fluid seal, mechanicallynon-contact seal. The motor and impeller assembly was fixed to a pumphousing with guide vanes. Results: Axial and radial deflections of the shaftwere less than a few micrometers for up to 8500 rpm. A flow of 5 L/min wasobtained at 8000 rpm at a pressure difference of 100 mm Hg. The bypassexperiment was performed in vitro. A pneumatic pump was used as the leftventricle. The axial flow pump was connected in parallel to the left ventri-cle as a bypass pump. With the increase of motor speed, bypass flowincreased and at 7000 rpm total bypass was obtained. The axial flow pumpworked normally under variable load conditions without active impellerposition control. Conclusion: The axial flow blood pump consisting of ahydrodynamic bearing, a magnetic fluid seal and a brushless DC motor ispromising as a long-term assist pump.

O 044 ADVANCEMENT OF AN IMPLANTABLE VENTRICULARASSIST SYSTEM USING UNDULATION PUMP UNDER MULTI-INSTITUTIONAL COOPERATIVE PROJECTK. Imachi1, Y. Abe3, Y. Mitamura2, T. Yambe1, T. Matsuda4, E. Okamoto5,M. Umezu6, I. Nemoto7, A. Mimaki8, I. Saito3. 1Tohoku Univ., Sendai, Japan,2Hokkaido Univ., 3The Univ. of Tokyo, 4Kyushu Univ., 5Hokkaido-TokaiUniv., 6Waseda Univ., 7Nemoto Project Industry Co. Ltd., 8Tonokura IkaKogyo Co. Ltd.Aim: We have been developing a fully implantable ventricular assist system(VAS) using undulation pump (UP) under multi-institutional cooperativeproject since 2002. The project is supported by the Program for Promotionof Fundamental Studies in Health Sciences of the Pharmaceuticals andMedical Device Agency (PMDA) for five years. The aim of this study is tointroduce the recent progress in this project. System: Implantable VAS iscomposed of UP, driving & control unit, internal and external batteries, tran-scutaneous energy transmission system (TETS) and transcutaneous infor-mation transmission system (tit*). UP is a kind of rotary blood pump inwhich the rotational motion of brushless DC motor is converted to undu-lation motion of a disc. UP is very compact, can produce arbitrary bloodflow pattern and a compliance chamber is not required. Results and Dis-cussion: UP having 69 mm in diameter, 35 mm thick and 331 g of weightincluding a brushless DC motor was developed. TETS with 110 mm in diam-eter of primary coil and 85 mm in diameter of secondary coil has 89% of

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DC-DC efficiency. Drive & control unit, lithium-ion internal batteries andtit* were incorporated into a case having 110 ¥ 80 ¥ 30 mm. Until now 6implantation of total system into goats weighing 35 to 48 Kg were performedwithout anticoagulant and 4 goats survived for 31.9, 31.5, 27.6, and 27.5 days,respectively. Two goats implanted only UP are surviving over 90 days and60 days, respectively. The results show the feasibility of this system.

O 045 DEVELOPMENT OF A DIPOSABLE AND IMPLANTABLE,MAGNETICALLY LEVITATED, CENTRIFUGAL BLOOD PUMPSFOR BRIDGE-TO-BRIDGE SUPPORT OF ACUTE TO CHRONICHEART FAILURE PATIENTSS. Takatani1, H. Hoshi1, K. Ohuchi1, H. Arai1, J. Asama2, T. Shinshi2,A. Shimokohbe2. 1Tokyo Medical and Dental University, Tokyo, 2TokyoInstitute of Technology, Yokohama, JapanMagnetic levitation of the impeller results in less activation of blood com-ponents leading to minimization of blood cell destruction and of blood coag-ulation in addition to longer durability of the device. We have developed atwo-degree active control mechanism in combination with a three-degreepassive control mechanism to realize a mechanically non-contact, compact,centrifugal blood pump. Active levitation of the impeller in the X- and Y-axis in combination with passive Z axis and two rotational axes was incor-porated into a disposable extracorporeal system and into an implantablelong term ventricular assist system for bridge-to-bridge circulatory supportof the heart failure patients. In the extracorporeal, disposable system, wehave attained an extremely low hemolysis index of 0.0008 g/100 L. The bloodcontacting surface treated with a MPC polymer allows at least one-monthheparin-less usage without coagulation. The dimensions of the implantablepump unit have been minimized to 65 mm diameter with 32 mm thickness,yielding the overall weight of 360 g. Both extracorporeal and implantablesystems allow various treatment options for end-stage cardiac patients.

O 046 DEVELOPMENT OF AN ULTRA-COMPACT WEARABLEPNEUMATIC DRIVE UNIT FOR VENTRICULAR ASSIST DEVICEA. Homma1, Y. Taenaka1, E. Tatsumi1, Y. Takewa1, T. Mizuno1, N. Katagiri1,H.S. Lee1, E. Akagawa1, T. Tsukiya1, K. Ota1, R. Kansaku1, Y. Kakuta1,S. Kitamura1, S. Hamada2, H. Mukaibayashi2, W. Iwaoka2, I. Shimosaki3.1National Cardiovascular Center, Osaka, 2IWAKI Co., Ltd., Saitama,3Medwill Technology, Inc., Osaka, JapanAim: The purpose of this work is to develop an ultra-compact wearablepneumatic drive unit for ventricular assist device. Methods: The drive unitconsists of a brushless DC motor, a crankshaft, a cylinder-piston, noncircu-lar gears and air pressure regulation valves. The reciprocating motion of thecylinder-piston makes the air pressure which drives the blood pump. Thenoncircular gears make systolic ratio and the air pressure regulation valvesregulate the maximum and minimum pressure in the cylinder-piston. Theweight of the drive unit is approximately 1.7 kg. Results: The drive unit was tested in an overflow type circulation mock test using a Toyobo VADblood pump of 70 mL of stroke volume. Pre-load and after-load were set at10 mm Hg and 120 mm Hg, respectively. The maximum flow rate was 7 L/minat 100 bpm. The drive unit also was examined in vivo an animal experiment.Holstein calf weighing 80 kg with the Toyobo VAD blood pump wore thedrive unit on his back. The pumping rate and the systolic ratio were set at80 bpm and 40%, respectively. The calf survived for more than 1 month ingood general condition. The bypass flow was maintained 3–4 L/min. Theelectric power consumption of the drive unit was maintained at around 12W. Conclusion: The performance of the ultra-compact wearable pneumaticdrive unit was confirmed in-vitro experiment and in-vivo animal study.These results indicate that developed drive unit has a potential to becomea mechanical circulatory support system of the human heart.

O 047 IMPLANTATION OF THE NEW MINIATURIZED MEDOSDIAGONAL PUMP AS LVAD IN SHEEPJ.D. Schmitto1, H. Dorge1, A. Tylla1, C. Siebert1, P. Ortmann1, C. Ballat1,M. Martin2, M. Akdis2, F.A. Schondube1. 1Department of Thoracic, Cardiacand Vascular Surgery, Georg August University Gottingen, 2Medos GmbHMedical Instruments, Stolberg, GermanyObjective: To evaluate the newly developed miniaturized MEDOS diago-nal pump as continuous flow LVAD for mid-term period. Material andMethods: The miniaturized MEDOS diagonal pump was implanted in 17sheep for seven days each. The inflow conduit was anastomosed to the leftatrium or apex and the outflow conduit to the descending aorta with thepump placed paracorporeal via left lateral thoracotomy. Anticoagulation

was done by intravenous heparin administration with a partial thrombo-plastin time of 100 s postoperatively. Follow-up was done by hemodynamicand echocardiographic data as well as daily blood samples. Animals werefollowed for 7 days and sacrificed for histologic examination. Results: Allanimals survived the surgical procedure and 12 sheep were pumped untilday 7 at a mean flow rate of 2.5 l/min. No relevant hemolysis was observedand hemoglobin levels remained stable (7.9 +/- 0.8 at day one to 7.5 +/-0.8 at day eight). Creatinkinase decreased to normal within days (1033 +/-507 U/l postoperatively to 27 +/- 10 U/l at day eight) and Troponin Tremained normal. Renal and liver function were slightly impaired periop-eratively, indicated by temporarily enhanced values of bilirubin and cre-atinine. Apico-aortic cannulation was significantly associated with earlybleeding complications. No significant thrombus formation occurred in thepump housing or inflow port of the pump. With atrio-aortic cannulation onlyminor emboli could be detected at autopsy. The new magnetic coupling ofthe rotor seem to further lower the small rate of thrombus formation at aslight increase of hemolysis. Wound infections did not occur. Conclusions:We conclude that the miniaturized MEDOS diagonal pump could be run asleft ventricular assist device for mid-term period and may serve as an alter-native to current technologies. The technique of atrio-aortal implantationof the inflow cannula may help to avoid bleeding and thrombembolic com-plications in sheep without significant hemolysis.

O 048 ALTERNATIVE USE OF TWO DIFFERENT VAD’S WITH ABCM CONSOLES IN PIGSD. Rodríguez-Martínez, I. Berenguer, S. Salom, A. del Cañizo*,J.F. Del Cañizo. Unidad de Medicina y Cirugía Experimental. HospitalGeneral Universitario “Gregorio Marañón”, Madrid, Spain. *Servicio deCirugía Pediátrica. Hospital General Universitario “Gregorio Marañón”,Madrid, SpainAim: to test the hemodinamical behaviour of two different VAD’s (BerlinHeart Excor and Medos VAD) with old BCM consoles (BCM 3200 andBCM 800). Methods: 6 large white pigs weighting 40–50 Kg were used totest the VAD’s. Input cannula was placed in two different ways: one troughthe left atrium by means of a left thoracotomy and other trough the apexby means of a medial sternotomy. In both cases output cannula was anos-tomosed to the aorta. Output flow and system pressures were registered bymeans of computerised system. In all cases, aortic pressure and pump flowwere properly maintained by BCM consoles despite the model of console(BCM 3200 or BCM 800). Conclusion: our results show that VAD’s can bedriven with different consoles without loss in its performance.

O 049 A TINY CENTRIFUGAL ROTARY VENTRICULAR ASSISTDEVICE (TinyPump) FOR CHILDREN AND INFANTSS. Takatani1, H. Hoshi1, K. Tajima1, J. Asama2, T. Shinshi2, K. Ohuchi1,M. Nakamura1, M. Yoshikawa3. 1Tokyo Medical and Dental University,Tokyo, 2Tokyo Institute of Technology, Yokoham, 3Ekisaikai Hospital,Nagoya, JapanA tiny centrifugal rotary ventricular assist device (TinyPump) has beendesigned for low flow circulatory support in children and infants. The designwas targeted to yield a compact and low priming volume pump with the flowrate of 0.5 to 4 L/min against the head pressure of 40 to 100 mm Hg. Theprototype TinyPump had the impeller diameter of 30 mm with six straightvanes. The impeller was supported with a needle type hydrodynamic bearingand driven with a six pole radial magnetic driver. The external pump dimen-sions were pump head height of 20 mm, diameter of 49 mm, and primingvolume of 5 ml, yielding the total weight of 150 g. In the mock circulatoryloop, the pump demonstrated the flow of 0.5–4.0 L/min against the headpressure of 40–100 mm Hg using 1/4≤ inflow and outflow cannula. Themaximum flow and head pressure of 5.25 L/min and 204 mm Hg, respec-tively, were obtained at the rotational speed of 3800 rpm. The maximumelectrical to hydraulic efficiency ranged from 15 to 25%. The index ofhemolysis was 0.0076 g/100 L which was similar to that of the BioPump BP-80. Although the TinyPump is compact and meets flow requirement of chil-dren, it has to overcome the inherent regurgitation problem that occursduring weaning process at low rpm. Further study is under progress priorto in vivo evaluation of the device.

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Cell Therapy

O 050 THE ROLE OF CELL DONOR AGE FOR THE CARDIO-VASCULAR TISSUE ENGINEERING CONCEPTS. Neuenschwander1, S. Holdener1, D. Schmidt1,2, I. Cummings1, M. Genoni2,G. Zünd1,2, S.P. ho*rstrup1,2. 1Department of Surgical Research, UniversityHospital Zurich, 2Clinic for Cardiovascular Surgery, University HospitalZurich, Zurich, SwitzerlandBackground: Saphenous vein cells can be obtained by a minor surgical inter-vention in local anaesthesia and therefore represent an attractive cell sourcefor cardiovascular tissue engineering. However, there are no “quality crite-ria” for future clinical application of tissue engineered transplants as tohuman cellular and matrix characteristics to provide maximum safety forthe cardiac surgery patient. In this study we investigate the influence of thecell donor age on the suitability for tissue engineering purposes. Methods:Sixteen primary cell lines representing typical age groups in cardiovascularsurgery were studied (AHA classification 45–54, 55–64, 65–74 and 75–85years). Monolayer cell growth was investigated for up to ten days using 96-well plates. The cells potential to grow in 3D culture was tested by seedingfive million cells per square centimetre on polyglycolic acid (PGA) stripscoated with poly-4-hydroxybutyrate (P4HB). The total cultivation time wasfour weeks. The number of cells on the scaffolds was assessed by the DNAcontent (Hoechst dye) and the tissue formation was evaluated by histolog-ical examinations and biochemical analyses (glycosaminoglycan andhydroxyproline content). Unilateral tensile stress tests were performed inorder to characterize the mechanical properties. Results: We did not finddifferences between the age groups regarding to the cell expansion as monolayers, 3D cell growth and extra cellular matrix formation nor did we findsignificant differences in the mechanical properties of the in vitro growntissues. Conclusions: The cardiovascular tissue engineering concept may be independent of cell donor age and therefore be suitable also for elderpatient populations.

O 051 UMBILICAL CORD BLOOD DERIVED PROGENITORCELLS—A NEW CELL SOURCE FOR PEDIATRIC CARDIOVAS-CULAR TISSUE ENGINEERINGD. Schmidt1, A. Mol1, S. Neuenschwander1, C. Breymann2, M. Gössi2,A. Weber1, G. Zund1, M. Turina1, S.P. ho*rstrup1. 1Department of SurgicalResearch and Clinic for Cardiovascular Surgery, University Hospital andUniversity of Zurich, 2Institute of Polymers, Swiss Institute of Technology(ETH), Zurich SwitzerlandPurpose: A substantial limitation to the surgical treatment of congenitalheart disease is the lack of appropriate growing replacement materials. Toaddress this shortcoming we focused on tissue engineered pediatric cardio-vascular replacements using umbilical cord blood derived endothelial progenitor cells (EPCs) and umbilical cord tissue derived myofibroblasts(UCMs), as a potential therapeutic new strategy for the repair of congeni-tal defects. Methods: UCMs were isolated from umbilical cord tissue, EPCsfrom 20 ml fresh human umbilical cord blood by density gradient centrifu-gation and cultured in EBM-2 medium containing growth factors. After pro-liferation and differentiation cells were analysed by immunohistochemistry.UCMs were seeded onto three-dimensional biodegradable scaffolds. Aftergrowing for 21d tissue replacements were endothelialised with EPCs.Additionally, a subgroup was mechanically stimulated in a bi-axial strainbioreactor. Analysis of the neo-tissues comprised histology, immunohisto-chemistry, extracellular matrix (ECM)- analysis and biomechanical testing.Results: Pre-seeding, EPCs showed constant endothelial phenotypes includ-ing CD31, vWF and eNOS. Histology of the replacements demonstratedlayered viable tissue formation in all samples. The seeded EPCs formed neo-endothelia with constant phenotypes. Major constituents of ECM suchas collagen and proteoglycans were biochemically detected. Stress-strainproperties of the neo tissues showed normal profiles. Conclusions: Livingengineered tissue replacements can be successfully generated from humanUCMs and EPCs. This cell sources may enable the tissue engineering of living, autologous replacement materials for early congenital cardiacinterventions.

O 052 NEW PROSPECTIVES IN MUSCLE CELL THERAPY: FROMSINGLE FIBER ISOLATION TO POLYMER SEEDINGL. Boldrin1, A. Malerba2, M. Flaibani3, E. Cimetta3, M. Piccoli1,M. Pozzobon1, C. Messina1, L. Zanesco1, P.G. Gamba1, L. Vitiello2,N. Elvassore3, P. De Coppi1. 1Stem Cell Processing Laboratory, Departmentof Pediatric Oncohematology, University of Padua, 2Department of Biology,Gene Transfer laboratory, University of Padua, 3Department of ChemicalEngineering, Tissue Engineering, University of Padua, Padova, ItalyBackground and Aim: Tissue engineering is a developing strategy to replaceor repair congenital or acquired large muscle defects and to improve theoutcome of muscle dystrophies and others genetic deficiencies. In our workwe have combined cell biology and polymer chemistry to create in vitro themost appropriate microenvironment for satellite cells in order to regener-ate muscle tissue in vivo. Methods: Following this propose, we have culturedsatellite cells using single muscle fiber technique to obtain a pure myogeniccellular population. Flexor digitorum brevis (FDB) muscles of adult GFPpositive mice were carefully removed. The single muscle fibers, obtainedafter enzymatic digestion, were plated in dishes coated with matrigel. Thesatellite cells obtained from the fibers were expanded and seeded ontopolymers. The polymers were made in PLGA (poly-glycolic acid), that dis-solves progressively when inserted into the muscles, and, according to thechemistry, designed to align the cells and to create a well organized systemto vehicle satellite cells in vivo. We performed biomolecular analysis (PCRand western blot) and we tested muscle markers expression, with immunos-taining and cytofluorimeter investigation, to affirm that our polymers are agood support, maintaining cell myogenicity. The polymers, with incorpo-rated GFP positive cells, have been introduced in tibialis anterior muscle ofisogenic wild type mice after mechanical damage. At 1, 2, 4, 8 weeks theanimals have been sacrificed and serial sections of treated muscle have beenanalyzed with immunofluorescence. Results: We observed the in vivo acti-vation of the transplanted satellite cells that were able to form fully differ-entiated muscle fibers. Furthermore the transplanted cells were also able tomigrate from the polymer to the damaged situ. Conclusions: This strategycould be used in the future as therapeutic tool for degenerative muscle dis-eases and/or for large muscle defects.

O 053 THE INFLUENCE OF DIFFERENT FREEZING MEDIA ONA PANCREATIC ISLET CELL LINE ENCAPSULATED WITHSODIUM CELLULOSE SULFATE (NaCS)V. Stadlbauer1, P. Stiegler2, S. Schaffellner2, G. Halwachs3, C. Lackner4,O. Hauser5, F. Iberer2, K.H. Tscheliessnigg2. 1Department of Internal Med-icine, Medical University Graz, 2Department of Surgery, Medical UniversityGraz, 3Department of Laboratory Medicine, Medical University Graz,4Department of Pathology, Medical University Graz, 5Institute of Virologyand Biomedicine, Veterinary University Vienna, AustriaIntroduction: The use of xenogenic islet cells is a possibility to overcomethe shortage of human donor organs for treatment of diabetes mellitus.Microencapsulation seems to be a promising method for immunoprotec-tion. Since isolation, purification, encapsulation and transplantation of isletcells are labour intensive, cryopreservation has emerged as an attractivesystem of islet banking. In this study NaCS, as a novel method for microen-capsulation of islet cells, was tested for its suitability during cryopreserva-tion. Methods: A pancreatic islet cell line (HIT-T15) was microencapsulatedin NaCS. Cells were frozen and thawed using three different freezing media(FM) containing different amounts of DMSO and glycerol (FM1 10%DMSO; FM2 40% DMSO, FM3 1M glycerol). Cell viability and cell growthwere monitored by a MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetra-zolium bromide) based cell growth kit before freezing and one week afterthawing, allowing the cells to recover. Results: Encapsulated and non-encapsulated show the same growing characteristics. The use of differentFM for cryoprotection of non-encapsulated HIT-T15 cells does not have anyimpact on cell numbers before freezing and after thawing. Cryoprotectionof encapsulated HIT-T15 cells with FM I leads to a decrease in cell numbersof 73% one week after thawing. Using FM II as cryoprotectant shows adecrease in cell numbers of 65% one week after thawing. Freezing with FMIII leads to an increase in cell numbers of 158% after thawing. Discussion:Islet banking of cells encapsulated in NaCS is possible. NaCS in combina-tion with FM containing glycerol seems to have a positive effect on cell sur-vival during islet-banking. As NaCS is less immunogenic and morebiocompatible than other materials used for microencapsulation it seems tobe a promising method for immunoisolation of islet cells to replace theendocrine pancreas in a physiological way.

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O 054 STEM CELL ENHANCED LASER MYOCARDIAL REVASCULARIZATIONS. Yang1, M. Cikirikcioglu1, J.-C. Tille2, J.-C. Pache2, A. Kalangos1,B.H. Walpoth1. 1Department of Cardiovascular Surgery, University Hospital, 2Department of Clinical Pathology, University Hospital, Geneva,SwitzerlandBackground/Aim: Cell therapy may represent a promising treatment forimproving cardiac function in end-stage heart failure. Laser revascularisa-tion induces angiogenesis and has proven useful to relieve anginal symp-toms. Our aim was to combine the two methods and to transplant syngenicbone marrow stem cells in an ischaemic and non-ischaemic rat skeletalmuscle. Methods: In 5 donor Sprague-Dawley rats bone marrow cells wereharvested. Mononuclear cell fraction was marked with PKH26 and quanti-tatively assessed by flow cytometry (FACS). These cells were immediatelytransplanted in a normal and ischaemic thigh muscle of 5 recipient Sprague-Dawley rats using the following 3 applications on each side a) cells only (1.5 Mio); b) CO2-laser only (10 W,500 ms); c) combination of a + b. Animalswere allowed to survive for one week (n = 2), 2 weeks (n = 1), 3 weeks (n = 1) and 4 weeks (n = 1). At sacrifice the 3 muscle regions were excisedfor histologic and cell evaluation (H&E, immuno-histo-chemistry andfrozen sections for immuno-fluorescence). Results: At all four time pointsPKH-marked living cells could be found and differentiated from the sur-rounding skeletal myocytes. The laser produced central necrosis, inflamma-tory reaction and focal angiogenesis. This was more pronounced in thecombined application with cells. No significant histologic differences wereseen in the ischemic compared to the non-ischemic muscle. Incubated cellssurvived and retained PKH marking in 71% at 4 weeks (FACS). Conclu-sions: Bone marrow cell transplantation combined with laser applicationshows a trend towards increased vital marked cells with more angiogenesiscompared to the other groups. Thus, cell therapy combined with laser maybe a promising method for myocardial repair.

O 055 MESENCHYMAL STEM CELL TRANSPLANTATIONIMPROVES CARDIAC FUNCTION OF FAILING HEART SUP-PORTED WITH LVADY. Takewa3, Y. Taenaka1, E. Tatsumi1, N. Nagaya2, R. Kansaku1, K. Ota1,A. Homma1, T. Mizuno1, S. Kitamura1, H. Takano1, R. Hajjar3. 1Dept. of Artificial Organs, National Cardiovascular Center Research Institute,Osaka, Japan. 2Dept. of Regenerative Medicine and Tissue Engineering,National Cardiovascular Center Research Institute, Osaka, Japan. 3Cardio-vascular Research Center, Massachusetts General Hospital, Boston, MA,USAAim: Improvement of cardiac function of failing heart supported with leftventricular assist device (LVAD) is important for increasing possibility of the bridge to recovery. We examined whether a cardiac regenerationtherapy such as mesenchymal stem cell transplantation was effective tosevere heart failure in goats supported with LVAD. Methods: Six adult goatsweighing 56.5 +/- 9.0 kg were created heart failure by infusing adriamycin(1 mg/kg) once a week for 5 weeks. All goats were instaled a pulsatile LVADand maintained systmic circulation sufficiently. Three out of six goats wereinfused autologus bone marrow-derived stromal cells (BMSC) which werepreviously cultured in vitro (BMSC group), and the rest 3 goats were notinfused them (control group). All goats were supported with LVAD for 4weeks, and cardiac function and hemodynamics were serially monitored.Results: The BMSC group recovered better cardiac function (the LV Ejec-tion Fraction (EF); from 41.8 +/- 12.8% to 47.0 +/- 14.8%) than the controlgroup did (EF; from 41.4 +/- 8.0% to 38.1 +/- 8.7%). Wall thinning of themyocardium and LV dilatation were more suppressed in the BMSC groupthan that in the control group. Conclusion: Additional regeneration therapyto severe failing heart supported with LVAD may contribute to recovercardiac function and increase the possibility of bridge to recovery.

O 056 HUMAN MESENCHYMAL STEM CELLS FROM BONEMARROW AND ALTERNATIVE SOURCES FOR THE RESCUE OFDAMAGED HEARTSC. Ventura*, G.P. Bagnara‡, S. Cantoni, C. Cavallini, F. Bianchi, F. Alviano‡,L. Pierdomenico‡, V. Fossati‡, A. Perbellini. Laboratory of MolecularBiology and Stem Cell Engineering—National Institute of Biostructuresand Biosystems, Institute of Cardiology, University of Bologna, ‡Depart-ment of Histology, Embryology and Applied Biology, University ofBologna, Bologna, ItalyLoss of cardiomyocytes due to myocardial infarction or hereditary car-diomyopathies, combined with the absence of regenerative capacity inmyocardial cells, represent causative factors in the progression toward heartfailure. Establishing ex vivo models of cardiogenesis in suitable populationsof human adult stem cells is therefore a major assignment in the perspec-tive of a cell therapy for damaged hearts. We have developed mixed estersof hyaluronan with butyric and retinoic acid (HBR) and provide evidencethat they acted as novel powerful cardiogenic agents in human mesenchy-mal stem cells (hMSCs) isolated from bone marrow (BMhMSCs), fetalmembranes (FMhMSCs), and dental pulp (DPhMSCs). HBR dramaticallyincreased the transcription of GATA-4 and Nkx-2.5, acting as cardiaclineage-promoting genes in different animal species. Exposure to HBR ulti-mately ensued in a high throughput yield of cardiomyocytes expressing -sar-comeric actinin. The differentiating a-myosin heavy chain and a sarcomericresponse was selective in nature, since HBR failed to affect the expressionof genes involved in skeletal myogenesis or neuronal specification. Thesefindings demonstrate the potential for chemically manipulating a geneprogram of human stem cell cardiogenesis without the need of gene trans-fer technologies and may set the basis for unprecedented approaches oftissue engineering and myocardial regeneration.

Clinical Aspects of Dialysis

O 057 A LOW PHASE ANGLE INDICATES A DECREASEDNUTRITIONAL STATUS IN CHRONIC DIALYSIS PATIENTSF. Dumler. William Beaumont Hospital, Royal Oak, MI, USABackground/Aim: the bioelectrical impedance phase angle provides anindex of cell membrane integrity and mass. We evaluated the relationshipbetween phase angle and nutritional and biochemical parameters in 185hemodialysis and 78 peritoneal dialysis patients. Methods: single frequencybioelectrical impedance analysis. Patient population demographics: meanage: 62 ± 14 years; 41% female; 35% black; 44% diabetic. Results:

Hemodialysis 1st Tertile 2nd Tertile 3rd Tertile

Number: 66 78 41

Phase angle (O): 3.63 ± 0.43 5.09 ± 0.54 6.75 ± 0.50

Weight (kg): 69.6 ± 15.7 76.5 ± 17.1 84.2 ± 15.4

S. Albumin (g/L): 36.9 ± 3.6 39.5 ± 2.5 40.3 ± 2.4

Fat Free Mass (kg): 51.5 ± 11.9 53.7 ± 12.9 60.5 ± 13.4

Body Cell Mass (kg): 19.9 ± 4.9 23.1 ± 5.6 28.7 ± 6.2

Peritoneal dialysis 1st Tertile 2nd Tertile 3rd Tertile

Number: 66 78 41

Phase Angle (O): 3.68 ± 0.14 5.11 ± 0.29 6.60 ± 0.21

Weight (kg): 76.8 ± 16.4 78.2 ± 14.9 87.9 ± 11.6

S. Albumin (g/L): 33.3 ± 6.2 37.3 ± 5.8 39.2 ± 3.6

Fat Free Mass (kg): 55.5 ± 15.2 57.4 ± 13.9 63.1 ± 12.8

Body Cell Mass (kg): 21.7 ± 6.1 24.9 ± 6.0 30.2 ± 6.2

Patients with a lower phase angle values had decreased body weight, BMI,BUN, serum creatinine, serum albumin and dietary protein intake valuesthan those in the higher tertile. Body composition parameters paralleled thechanges in biochemical nutrition markers (P < 0.0001 for all parametersshown above). Conclusion: these results suggest that phase angle is a usefultool for identifying dialysis patients at high risk for malnutrition.

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O 058 GLUCOSE AND METHYLGLYOXAL EFFECT ON ICODEX-TRIN PERITONEAL TRANSPORT: IN VITRO COMPARATIVESTUDIESB. Szary, K. Czyzewska. Department of Chemistry and Clinical Biochem-istry, Poznan University of Medical Sciences, Poznan, PolandBackground/Aim: Icodextrin and icodextrin plus glucose solutions havebeen used in peritoneal dialysis for the development of an effective ultra-filtration. In standard fluid glucose partly degrades to the reactive carbonylsubstances changing cell morphology and functions. The aim of the in vitrostudies was to compare the influence of glucose and its degradation product(methylglyoxal) on icodextrin diffusion rate across the peritoneal mem-brane. Methods: The parietal peritoneum from New Zealand male rabbitswas an experimental model. Tissue was placed into a modified Ussingchamber and connected with a fluid reservoir. Transfer of icodextrin (7.5 g/dL) from the mesothelial (M) to the interstitial (I) side of the peri-toneum was studied in: the control stage, after introduction of glucose (1.8 g/dL) and methylglyoxal (1 mg/dL), in separated series. The results werecalculated using mathematical model and expressed as a diffusive perme-ability coefficient (P). Results: In the control conditions the rate of icodex-trin passage from the mesothelial to the interstitial side of the peritonealmembrane was constant and mean value of P ± SEM (standard error of themean) amounted 0.194 ± 0.035 [¥10–4, cm/s]. Application of glucose causedthe increase of icodextrin transport by 94% (p < 0.005). There were nochanges of icodextrin transfer parameters after methylglyoxal introductioninto the experimental system. Conclusion: Glucose but not methylglyoxalintensifies icodextrin transport from the mesothelial to interstitial side ofthe peritoneum in vitro and it may be important for the efficiency of peri-toneal dialysis.

O 059 CAN WE IMPROVE BONE TURNOVER TROUGHOUTTREATMENT WITH DIFFERENT DIALYSATE CALCIUM CONCENTRATION?G. Spasovski1, S. Gelev1, A. Sikole1, J. Masin-Spasovska1, M. Bogdanova2,V. Amitov1, N. Stojcev1, R. Grozdanovski1, M. Polenakovic1. 1Dept. ofNephrology, 2Institute of Biochemistry, Clinical Center, Skopje, MacedoniaAim: Our study aimed to compare the effects of low (Ld) and high dialysate(Hd) calcium concentration on the evolution of adynamic bone disease indialysis patients. Methods: 52 ABD patients with parathyroid hormone(PTH) < 100 pg/ml and bone alkaline phosphatase (BAP) < 37 U/L wereequally randomised to Ld (1.25 mM) and Hd (1.75 mM) calcium concen-tration. The duration of the study was 6 months and the only phosphatebinder was calcium carbonate. Blood samples for bone markers and routinebiochemistry were taken at scheduled intervals. Results: The groups didn\’tdiffer in the mean serum total calcium (tCa) before dialysis, but it was sig-nificantly increased in Hd group after the dialysis (2.59 +/- 0.18 vs 2.44 +/-0.19; p < 0.01). Mean tCa in Ld group did not change during dialysis, whileit was markedly increased after dialysis in Hd group (2.59 +/- 0.18 vs 2.41 +/- 0.21; p < 0.01). When compared with Hd group, patients in Ld grouphad significantly lower mean ionised serum calcium (iCa) before (1.08 +/-0.02 vs 1.04 +/- 0.02; p = 0.02) and after dialysis (1.16 +/- 0.10 vs 1.09 +/-0.10; p < 0.01), respectively. A significant increase in mean postdialysis iCawas observed in Hd group (1.09 +/- 0.10 vs 1.16 +/- 0.10; p < 0.01) while nomodification was observed in Ld group. There was no difference in pre-dialysis phosphate levels and the average dose of calcium carbonate duringthe study. Mean serum levels of iPTH, bone and total alkaline phosphatasein Ld group were significantly increased at the end of the study comparedwith the baseline levels [(65.13 +/- 55.74 vs 38.63 +/- 22.96; p < 0.05);(35.35 +/- 22.46 vs 23.38 +/- 7.26; p = 0.01); (85.24 +/- 38.14 vs 59.46 +/-18.69; p < 0.01)], respectively. The most common side effects of the treat-ment with dialysate Ca of 1.25 were hypotension and cramps in 16% and17% of the dialysis sessions, respectively. Conclusion: There was an evolu-tion towards higher bone turnover in patients treated with dialysate calciumof 1.25 mM, probably by inducing a negative calcium balance and causingrepetitive stimulation of PTH secretion in each dialysis. Hence, this mightbe considered a valuable treatment for ABD patients, although this ratherbeneficial and not harmful effect should be confirmed in a long-term evaluation.

O 060 PREVENTION OF HYPERCALCEMIA IN DIALYSISPATIENTSA. Sikole, G. Spasovski, S. Gelev, R. Grozdanovski, P. Dzekova, V. Amitov,N. Stojcev. Department of Nephrology, University of Skopje, Skopje, R.MacedoniaEpisodes of hypercalcemia are frequently observed with the use of calciumcontaining phosphate binders. They can be problematic when calcitriol isindicated for control of high parathyroid hormone levels. Then, the risk foroccurrence of soft tissue calcifications could increase. This investigationcompares the efficacy and safety of lanthanum carbonate and calcium car-bonate. Twenty-two patients, initiated onto hemodialysis within 12 weeks ofrecruitment to the study, were randomized to start on either lanthanum car-bonate (10 patients) or calcium carbonate (12 patients). Lanthanum car-bonate tablets contained 250 mg lanthanum, while calcium carbonate tabletscontained 500 mg calcium. The treatment was conducted for 48 weeks.Blood samples were taken predialysis at each study visit to assess bio-chemical, hematological and bone marker parameters. We evaluated 22patients, 12 male (6 in the lanthanum group) and 10 female (4 in the lan-thanum group), aged 55 ± 10 years for the lanthanum and 57 ± 10 years forthe calcium group. Patients received 12 hours of hemodialysis treatment per week, using bicarbonate dialysate with calcium concentration of 1.75 mmol/L, and low-flux polysulfone membrane of 1.3 m2. KT/V was 1.14± 0.27 for the lanthanum and 1.1 ± 0.11 for the calcium group. The meandose of lanthanum carbonate was 1286 ± 488 mg daily. The mean dose ofcalcium carbonate was 2205 ± 1076 mg daily. Serum phosphorus levels werebelow 1.8 mmol/L in both groups throughout the study. There was adecrease in the serum calcium levels of the lanthanum group. Episodes ofhypercalcemia occurred in 50% of the patients during treatment withcalcium carbonate, but there was no occurrence of hypercalcemia duringtreatment with lanthanum carbonate (p < 0.01). Hypocalcemia occurred in70% of the patients in the lanthanum group and in only 33% of the patientsin the calcium group (p < 0.01). The serum levels of 25 hydroxyvitamin D,intact PTH, bone specific alkaline phosphatase did not change significantlyduring the study in either group. Lanthanum carbonate was well tolerated.No serious adverse events occurred during the study. We could concludethat lanthanum carbonate was an efficient and safe non-calcium containingphosphate-binding agent. Using lanthanum carbonate, one could bettercontrol hypercalcemia in dialysis patients.

O 061 SHOULD WE DIALYZE MORE FREQUENTLY OR PRO-LONGED TO REMOVE UREMIC TOXINS, OTHER THAN UREA?S. Eloot1, R. De Smet2, P. Verdonck1, R. Vanholder2. 1Institute BiomedicalTechnology, Hydraulics Laboratory, Ghent University, 2Nephrology Section,Internal Medicine, Ghent University Hospital, BelgiumAim: Because patients with renal failure retain a large variety of uremicsolutes, we investigated the influence of a personalized therapy deviatingfrom the standard dialysis scheme of three times four hours a week. Methods:This study included 6 stable hemodialysis patients undergoing a standard lowflux polysulphone dialysis (F8 and F10HPS). Blood samples were collectedfrom inlet and outlet blood lines at multiple time points during dialysis. Basedon the measured plasma concentrations, a two-pool kinetic model was cali-brated for each compound under study: urea, creatinine (CTN), guanidi-nosuccinic acid (GSA), and methylguanidine (MG). This model allowstheoretical calculations, simulating different dialysis strategies: daily shortdialysis, prolonged dialysis three times per week, daily long slow dialysis,and standard dialysis with enhanced solute clearances. For each strategy insteady state, mean and pre dialysis patient plasma concentrations were com-pared to standard dialysis. Results: Because GSA is distributed in a smallervolume (30.6 ± 4.2 L) and CTN and MG showed significantly larger distri-bution volumes (54.0 ± 5.9 L and 102.6 ± 33.9 L) compared to urea (42.7 ±6.0 L), intra- and inter-dialytic kinetic behaviors are different. Solutes distributed in a smaller volume, like GSA, take more advantage of short dailydialysis (pre and mean concentration decrease of 25.6 and 20.6% comparedto 21.4 and 15.6% for urea). Compounds distributed in a larger volume showa stronger reduction when performing prolonged dialysis (mean concentra-tion decrease of 31.8 and 31.5 for CTN and MG when compared to urea(25.7%)) or standard dialysis with increased clearance (mean concentrationdecrease of 12.8 and 15.7% for CTN and MG compared to urea (11.5%)).Daily long slow dialysis results in pre and mean concentration decreases of more than 65 and 70%, respectively. Conclusion: In conclusion, our modelconfirms the necessity for an individualized dialysis therapy approach toanswer the question of more frequently or prolonged dialysis.

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O 062 BLOOD LINES CONDUCT LEAKAGE CURRENT DURINGHEMODIALYSIS. A POTENTIAL SAFETY RISK DURING FIRSTFAILURE, ESPECIALLY FOR THE PATIENTS WITH CENTRALDIALYSIS CATHETER AS ACCESSP. Jonsson1, G. Eliasson2, B.G. Stegmayr3. Department of Biomedical Engi-neering and Informatics1, Department of Biomedical Engineering2, andDepartment of Internal Medicine3, University Hospital, Umeå1,3, and Danderyd2, SwedenHemodialysis (HD) machines are IEC-classified as I type B. When usingcentral dialysis catheters (CDC) for access there will be a close contact withthe heart. To investigate the risk for HD patients we measured the leakageof current through the tubing set during in vitro dialysis performed accord-ing to the IEC 60 601–1 regulations for class I CF. Eight runs were donewith Gambro GFS + 12 dialysers, first with saline and then with blood in theblood lines for each run. The leakage current exceeded the CF-limit (<50mA) at the top of the CDC using the test “mains on applied part” for saline(median 1008 mA, range 720–1241), for blood (median 610 mA, range449–772) and also for a “single fault condition” using saline (median 68 mA,range 35–118) or blood (47 mA, range 4–128). In “single fault condition” thehighest leakage current at the CDC (128 mA) almost exceeded the earthleakage current in normal condition. A safety risk may appear if a “singlefault” arises in the dialysis machine or another device connected to the samepatient, or during “mains contact to the patient”. Then the current flow maybe high enough to cause arrhythmia for the patient, especially when usinga CDC. These data and the use of CDC as access for dialysis indicate thatHD machines should be classified as cardiac floating rather than body.

O 063 DIALYSIS DELIVERY PROCESS CONTROLM. Alquist1, J. Hegbrant2, J.P. Bosch3. 1Gambro Corporate Research, Lund,2Gambro Healthcare Lund, 3Gambro Chief Medical Office, Stockholm,SwedenBackground: The ability to deliver dialysis in adherence to guidelines is afunction of prescription and delivery process control. Process controlagainst targets is given by the mean and the standard deviation (SD) of aprocess outcome. Methods: To assess dialysis delivery process control,spKt/V-urea (normally distributed) can be used as process outcome. Normaldistribution gives the percentage dialysis doses delivered above and belowa target. Based on delivered mean spKt/V and its variation (SD), a newmean spKt/V required to reach a specified number of treatments above atarget at current SD as well as a new SD required to reach target at currentmean spKt/V, can be calculated. EBPG guidelines recommend an spKt/Vof at least 1.4 (thrice weekly), here used as the lower target. Results: Medicaloutcome data from 2 European countries (GHcI) and US (GHc US) wasused for calculations. The countries’ mean spKt/V was 1.47, 1.44 and 1.50,and the SDs 0.22, 0.31 and 0.32, respectively. This results in 37.4%, 44.8%and 37.4% of dialyses below a target of 1.4. To reach a hypothesized goalof only 5% of treatments below target, at current SD the mean spKt/Vwould have to increase to 1.77, 1.91 and 1.93, and at current mean spKt/Vthe SDs must be reduced to 0.04, 0.02 and 0.06, respectively. With theincreased mean, 17.4%, 10.9% and 10.3% of the dialysis doses deliveredwould be in the range 1.4–1.6 and 77.6%, 84.1% and 84.7% above 1.6.However, with the reduced SDs, 95.1%, 97.7% and 91.5% would be in therange 1.4–1.6. Conclusion: Increasing the mean spKt/V would result in ade-quate dialysis for most patients. However, the dialysis doses delivered wouldin a significant number exceed the range 1.4–1.6 with 50% of delivered dosesabove the new higher means. Accordingly, this would increase treatmenttimes and costs as well as patient dissatisfaction. Finding ways to increasethe process control and to reduce the variation (SD) would be a betterapproach to assure treatment quality.

O 064 COMPLEMENTARY AND ALTERNATIVE MEDICINE(CAM) AS A DISCIPLINARY APPROACH TO LONG-TERM MAIN-TENANCE HEMODIALYSIS (HD) THERAPYT. Agishi, M. Akamatsu,Y. Okuno. Blood Purification Center, Itabashi ChuoMedical Center, Tokyo, JapanBackground/Aim: Symptoms related to the generalized amyloidosis and thearteriosclerotic obstruction, such as represented by intolerable pains andrestricted movability mainly in the multiple joints and the limbs, are themost frequently-observed disastrous ill conditions in long-surviving main-tenance HD patients. Even though not bringing the patients to immediatedeath, these which can not be ameliorated by the so-called modern scien-tific medicine currently applicable severely impair a quality of the daily life.

CAM, as a matter of fact, is a complexity of wide variety of therapeuticmodalities, some of which are not even recognized to be included in medi-cine, but sometimes show miraculous effects in the patients who can not betreated by the modern medicine. Yes, let us remind that the miracle is a termgiven to the phenomenon which can not be explained by the contemporar-ily-prevailing scientific knowledge. However, many advancing peoplesnowadays realize that the modern science is one of tools to understand thenature and has a limit to adopt. Methods: External qigong, acupuncture andartificial CO2 hot-bath have been applied to the HD patients in our center.Results: Favorite Effects are listed as follows. External qigong; A relief ofpain was obtained effectively in 100.0%(26 effective cases/26 total cases).Leg temperature was thermographically raised effectively in 96.2%(25/26)as high as 4.3°C. An extent of joint movability was widened. Improvementin plethysmography and peripheral blood flow measured by Doppler echoflowmetry was observed. Acupuncture; A relief of pain was amelioratedeffectively in 57.5%%(23/40). CO2 bath; Foot and toe necrosis improved toeven disappear effectively. Conclusion: In conclusion, CAM is recom-mended to be included as a disciplinary approach to the long-term mainte-nance hemodialysis therapy in order to improve patients’ QOL.

Assist Devices

O 065 WEARABLE PNEUMATIC BIVENTRICULAR ASSISTDEVICE WITH BELLOWS MECHANISMC.M. Hwang1, G.S. Jeong1,2, M.W. Jung1,2, J.S. Kang1,2, J.J. Lee1, Y.D. Park1,K.B. Lee1,2,3, K. Sun1,2,3,4. 1Korea Artificial Organ Center, Korea University,2Brain Korea 21 Program for Biomedical Science, Korea University,3Department of Biomedical Engineering, Korea University, 4Department ofThoracic and Cardiovascular Surgery, Korea UniversityBackground/Aim: The conventional pneumatic drivers for ventricular assistdevice (VAD) have been relatively large in size and heavy in weight.Recently, portable size drivers are developed and applied in clinical area togive the patients extended scope of activity and convenience of daily life.In this study, small size pneumatic VAD system is developed in Korea Arti-ficial Organ Center, and the design change and major problems are underoptimization process. Methods: In this wearable size pneumatic VAD,bellows mechanism is applied for pressure modulation. This bellows mech-anism enables small size and reduced weight actuator system. By ballbearing system, pusher plates can move linearly to squeeze the pusherplates. The alternating movement of pusher plates enables biventricularassist pressure generation. Pressure compensation system is also developedto prevent the pressure drop and pump function variance, which is inducedby the air leakage of pneumatically closed system. Pressure compensationsystem consists of pressure sensor, control board, air pump and solenoidvalve. The blood pumping part has heart valves, polyurethane housing anddiaphragm or blood sac,The bellows mechanism enabled smaller driver sizeof 20 ¥ 30 ¥ 8 cm3 and reduced weight of 4.0 kg including the actuator, con-troller and battery. Short range wireless monitoring is possible with blue-tooth module. This wireless monitor/controlling function will improve themobility of the patients. From the in vitro experiment result, this driver cansupport 6.5 L/min at 100 bpm. And the in vivo animal study showed goodperformance as ventricular assist device. Results and Conclusion: Thebellows and motor driven push-pull mechanism is simple for pneumaticbiventricular assist device and could have reduced size and weight for wearable device. This device is relatively small compared to conventionalpnaumatic console and can be applied wearable VAD console.Acknowledgement: This study was supported by a grant of the KoreaHealth 21 R&D Project, Ministry of Health & Welfare, Republic of Korea.(02-PJ3-PG6-EV09-0001)

O 066 HYBRID DRIVING UNIT FOR HEART ASSIST DEVICESM. Darlak, M. Gawlikowski, R. Kustosz, A. Korczak*, G. Peczkis*, Foun-dation for Cardiac Surgery Development in Zabrze, *Silesian University ofTechnology in Gliwice, PolandAim: Hydraulic centrifugal pump could be used in construction of portabledriving unit for pneumatic heart support pumps. Evaluation of functionalfeatures of the unit was the goal of the project. Methods: The electro-hydro-pneumatic converter producing a pneumatic signal using forPOLVAD pulsatile heart assist devices direct driving was developed. Thelaboratory model of driving assembly utilizing centrifugal pump with spiraloutlet channel as a source of hydraulic flow was build. For continuousenergy distribution maintenance during the work cycle, hydraulic accumu-

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lators were applied. Various parameters of pneumatic and hydraulic signalswere obtained regarding valves work and rotational pump speed combina-tions. Set of flow and pressure sensors connected to critical model pointswith PC module was used for data collecting. Power consumption was alsoexamined. Results: Control and initial parameters of the model was opti-mized for correct flow and pressure profiles in POLVAD pump output. Thetotal efficiency of the model from electrical supply to blood energy outputreached 8%, assuming power level of the POLVAD pump output about 2 W. Conclusions: Energy and hydrodynamic analysis showed, that suchassembly of electro-hydraulic-pneumatic modules can be successfully usedfor driving pneumatic blood pump. The only claim is reduction of energydissipation in consecutive converters. It can be obtained for example by useof materials with better tribologic parameters or hydraulic channels’ pro-files optimization.

O 067 ADAPTIVE TRANSCUTANEOUS ENERGY TRANSFERSYSTEM (TET) FOR IMPLANTABLE DEVICESB. Vodermayer1, R. Gruber1, T. Schmid1, W. Schiller2, G. Hirzinger1,D. Liepsch3, A. Welz2. 1Institute of Robotic Systems, German AerospaceCenter (DLR), 2Heart Surgery Clinic, University of Bonn, 3Institute forBiotechnic, MunichAim: The wireless transfer of energy into the body is a major requirementfor future implants. The adaption of transmitted energy to the actualdemand of the implant should reduce the exposure to electromagnetic radi-ation and enhance the longevity of the electronic components. Slender,coreless coils are desirable to avoid disturbance of the tissue and providesufficient circulation in the vicinity. Methods: An inductive TET with twocoils, an external control unit, external accumulator and an implantable electronic (IE) with back-packed accumulators was developed. Theimplantable, coreless coil is a flexible ring made of braided copper (diame-ter 150 mm, thickness 8 mm, weight 70 g) with integrated infrared transceiverfor data transfer. The IE provides an integrated processor for data-acquisi-tion, brushless motor control and data-communication. For IR-transmis-sion, a robust protocol was developed. The software adapts the energy tothe demand of the implant, manages charging and provides basic function-ality for adaptive implant control. The frequency is automatically adjusted(121–130 kHz) to optimise the efficiency. Results: The system was able totransmit up to approx. 50 W at 50 mm distance between the coils. Infrareddata-communication between the implant and the extra-corporal unitshowed no problems through porcine tissue (data rate: 115 kbit/s). Thecontrol algorithm for the power adaption was able to balance all major andminor electrical disturbances. The maximum efficiency of the system wasapprox. 78% at 5 mm distance between the coils and 61% at 10 mm. A hor-izontal and/or vertical displacement of the coils of 20 mm led to a decreasein efficiency of approx. 5%. Higher distances (>25 mm) reduced the effi-ciency to approx. 50% and led to increased temperature of the external con-verter. No warming was measured between the coils under any operatingcondition. Conclusion: The TET showed reliable transmission even at highhorizontal and vertical displacements. Transmitted energy was automati-cally adapted to the demand, high power requirements were effectivelycompensated. The temperature of the implanted components did not exceedcritical values. Animal studies showed no impact to the tissue near the coils.

O 068 THE NEW CRITERION OF PULSATILE BLOOD FLOWESTIMATION BASED ON EXTRACORPOREAL HEART ASSISTDEVICE POLVADM. Gawlikowski1, R. Kustosz1, T. Pustelny2, M. Darlak1. 1Artificial HeartLab., Foundation for Cardiac Surgery Development, Zabrze, 2Physics Insti-tute, Silesian University of Technology, Gliwice, PolandAim: Commonly used criterion for flow pulsation quality estimation is theenergy equivalent of pressure (EEP) related to mean arterial pressure(MAP). During in-vitro investigations of extracorporeal heart assist devicePOLVAD there was observed, that some of unphysiological flows had phys-iological EEP/MAP ratio. To achieve closer to physiological flow classifica-tion, other criterions were defined and compared with EEP/MAP ratio.Methods: To physiological pulsatile flow estimation there were defined fol-lowing ratios: shape ratio Ks and pick ratio Kp The in-vitro experimentswere performed on heart assist device POLVAD connected through theinlet and outlet cannulas to the physical Windkessel’s model. The dataacquisition system was registered pressure at the end and flow through theoutlet cannula. By analysis of these waveforms the following ratios werecalculated: mean arterial pressure (MAP), energy equivalent of pressure

(EEP), shape ratio (Ks) and pick ratio (Kp). The investigations were per-formed for different driving pressures and pump work frequency. Results:For typical non physiological pulsatile flows the EEP/MAP = 1.22 ± 0.04,for physiological pulsatile flows EEP/MAP = 1.64 ± 0.14. There was a groupof flows with physiological pulsation shape, for which EEP/MAP ratio wasrelatively low (1.32, 1.37, 1.26). The statistical analysis of shape ratio Ks andpick ratio Kp indicated, that for physiological pulsatile flows Ks = 2.76 ± 0.3and Kp = 0.51 ± 0.09. For unphysiological pulsatile flows one or both of theseratios are out of range. Conclusions: Except the EEP/MAP ratio the usefulcriterion for qualification the blood flow pulsation can be shape and pickratios estimation. The flow is physiological pulsatile when Ks � 2.7 and Kp � 0.51. If one or both of these parameters are out of optimal values,the flow maintains pulsation but become less physiological.

O 069 SEMI-AUTOMATIC DETECTION OF CHARACTERISTICPOINTS OF CARDIOVASCULAR SYSTEM ELEMENTS PROSTHE-SES TEST CONTROL SINGNALSP. Kostka1,2, Z. Nawrat1. 1Foundation for Development of Cardiac Surgery;2Technology University of Silesia, Institute of Electronics, Gliwice, PolandBackground: Pneumatic and hydraulic pressure and flow signals, measuredon working cardiovascular element prosthesis during the test, describe itstemporal hydrodynamic conditions. Because of nature of signals describingbiological objects, they often can be time-varying, transient, non-stationaryand affected by multi-sources noise. It makes in some situations character-istic points of pressure-flow curves unseen in time domain and automaticdetection of these important instants is very difficult or even not possible.Methods: Time-frequency (T-F) analysis approach is proposed, wheresignals are decomposed into adaptive, frequency sub-bands, using wavelettransform (WT), which is known as a suitable tool for biomedical non-stationary signal analysis. The most significant WT component is furthersmoothed using the Savitzky-Golay filter and then adaptive threshold dis-criminates the localization of characteristic points e.g. the VAD full ejection(FE) or full fill moments (FF). Results & Conclusion: The most represen-tative Mallat decomposition level was estimated as details d1 and d2, whichcorrespond to the highest frequency bands. Next result group showed theperformance of automatic FE and FF pressure and flow curves peaks detec-tion between 70–85% accuracy. Elaborated software allows on humanexpert intervention on every stage of procedure to make decision of peakplacement in case of more complex cycles.

O 070 MULTI-TYPE SENSOR TEST PROCEDURES OF POLISHCARDIAC SURGERY TELEMANIPULATOR-ROBIN HEARTFAMILYP. Kostka1,2, Z. Nawrat1, S. Pietraszek2, Z. Malota1. 1Foundation for Devel-opment of Cardiac Surgery; 2Technology University of Silesia, Institute ofElectronics, Gliwice, PolandBackground: Performance evaluation of three versions of Robin Heart-polish telemanipulator for usage in cardiac surgery, base on registration andanalysis of the real robot arm trajectory is presented. The basic task con-sisting in mapping the hand movements of surgeon (operator) into tool armmovement was characterized as well as additional important function (e.g.scaling, tremor removing) and parameters describing whole system wereestimated. Methods: Signal recorded from motor optical encoders, gyro-scope and accelerometer sensors, placed directly on the arm to record themotor axis and real external trajectory were the source of informationallowed to elaborate the wide spectrum of tests: •1.comparison of synchro-nized recorded trajectory of user tool and robot arm to estimate the scalingfactor, time delay and the filtering, •2.vibration analysis in several placedincluding the robot tool tip, •3.the hystheresis and repeat tests for both arms•4.assessment of control systems computational efficiency for given task.Sophisticated signal processing methods were used to extract useful infor-mation from original sensor signals. Results & Conclusion: The usage oftechnological top semiconductor sensors for acceleration and angle veloc-ity measurements opened the new field of robot dynamic properties studywith special application to medical robot trajectory evaluation.

O 071 TRIBOLOGICAL ANALYSIS OF BLOOD IMMERSEDMECHANICAL BEARINGS IN ROTARY BLOOD PUMPSM. Akdis, M. Martin, H. Reul† (†passed away on Nov. 3, 2004). HelmholtzInstitute for Biomedical Engineering, Aachen, GermanyBackground: Long-term durability of a rotary blood pump mainly dependson hematological and tribological limitations of the pump system that are

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primarily related to blood immersed rotor bearings, since these types ofbearings are likely associated with low flow velocities, frictional heat andproceeding wear. Therefore, extensive tribological studies have to be per-formed on the rotor bearings to estimate the potential life time of the VADsystem. Methods and Results: The Microdiagonal Pump is a miniature sizemixed flow rotary blood pump, which incorporated blood immersed bear-ings in its initial design. To elucidate the tribological behaviour of the rotorbearings a series of wear studies and bearing temperature analyses havebeen performed and evaluated. Wear studies revealed a degressive charac-teristic depending on bearing material and operating conditions. Unless thewear rate exceeds a critical value sufficient rotor stability was observed.Bearing temperature was mainly affected by thrust loads and washout flows.Conclusions: Bearing tribology plays a major role in long-term durability ofa rotary VAD system and has to be carefully investigated prior to clinicaluse.

Bioreactors

O 072 MICROWAVE TREATMENT COMBINED WITH PULSATILECIRCULATION CAN COMPLETELY REMOVE CELLS AND a1–3GALACTOSE ANTIGENK. Iwasaki1, S. Ozaki2, T Kawai3, Y. Moriyama3, Y. Ohzeki2, M. Umezu3.1Institute for Biomedical Engineering, Waseda University, 2Department ofCardiovascular Surgery, Ohashi Hospital, Toho University, 3Major in Inte-grative Bioscience and Biomedical Engineering, Graduate School ofWaseda University, Tokyo, JapanAim: We previously showed that a novel microwave treatment combinedwith pulsatile circulation successfully produced cell-free heart valve tissues.Thick and dense aortic valves were completely decellularized along withmaintaining natural structures. The aim of this study is to develop thesecond-model decellularization device that treats valves in a sterile condi-tion. Moreover, a1–3 galactose antigen which is a crucial cause of hypera-cute immuno-rejection in tissue transplantation from pig to human wasexamined. Methods: The second device consists of an air-contactless pul-satile circuit and a microwave irradiation unit. Heart valves were mountedinto a chamber and incorporated in the circuit. Based on the design thatmicrowave irradiation unit can be rotated around the valve chambers,hom*ogeneous decellularization of heart valve tissue was realized. 1 wt% ofdeoxycholic acid was used, and aortic as well as pulmonary valves weretreated for 24 hours. Results: The examination of decellularized tissues val-idated that the whole processes of tissue treatment were sterile and not con-taminated. Hematoxylin Eosin staining showed that cell nuclei werecompletely removed from both aortic and pulmonary valves. Moreover,immuno-staining result successfully showed a1–3 galactose antigen waseliminated by the novel treatment. Tensile tests indicated that mechanicalproperties of decellularized tissues were comparable to native tissues.Decellularized aortic valves were endothelialized by a pulsatile bioreactor,and, are under animal experiments. Conclusion: The novel treatment suc-cessfully produced cell-free aortic heart valves without a1–3 galactoseantigen. These valves are considered quite safe and promising for futureclinical application.

O 073 DEVELOPMENT OF SMALL-CALIBER “BIOTUBE” VAS-CULAR GRAFTS: PRELIMINARY ANIMAL IMPLANTATIONSTUDYT. Watanabe1,2, H. Huang1, K. Hayashida1,2, Y. Okamaotoy, Y. Nemoto3,K. Kanda2, H. Yaku2,Y. Nakayama1. 1Dept. of Bioengineering, National Car-diovascular Center Research Institute, Osaka, 2Dept of CardiovascularSurgery, Kyoto Prefectural University of Medicine, Kyoto, 3Bridgestone Co.Tokyo, JapanBackground: We are developing functional autologous tubular tissues,named “BIOTUBEs”, as ideal small-caliber vascular grafts that have growthpossibility without immunological rejection. BIOTUBEs are constructed by“in body tissue architecture” technology under the novel concept of regener-ative medicine. In this study, with some modification to improve surgical han-dlings in anastomosis, the autologous BIOTUBEs were practically implantedto the carotid arteries of rabbits and exposed to the hemodynamic conditionsin vivo. Materials and Methods: Silicone rods (diameter: 2 mm, length:20 mm) were covered with polyurethane sponge tubes (length: 3 mm) at theirboth ends as “reinforcement cuffs”. The assembled scaffolds were placed intodosal skin pouches of rabbits (Japanese White rabbit, 2 kg). After 1 month,BIOTUBEs formed around the scaffolds were bilaterally implanted to the

carotid arteries of the same rabbits. Results: The obtained BIOTUBEs had hom*ogeneous thin connective tissue walls (thickness: ca. 0.1 mm) mostlyconsisting of collagen and fibroblasts,high burst strength (>2000 mm Hg),andequivalent compliance to that of native arteries. The interstices of the “cuff”sponge tubes were occupied and covered with the same connective tissues toform seamless organisms with BIOTUBEs. Due to the reinforcement byimpregnated cuffs, end-to-end anastomosis between the BIOTUBEs and thenative arteries was very easy. Angiographic observations up to 2 monthsshowed no formation of aneurysms or rupturing. Little thrombus formed on the luminal surfaces that were partially covered with endothelial cells.Morphological investigation revealed that hierarchical vascular wall struc-ture with circumferential orientation of collagen and integrated cells wasconstructed. Conclusion: BIOTUBEs could be very practical substitutes forsmall caliber arteries, which are implantable by conventional microsurgerytechniques. Further study is ongoing to investigate morphological and physi-ological changes of the implanted BIOTUBEs in vivo.

O 074 DEVELOPMENT OF “IN BODY TISSUE-ARCHITEC-TURAL” AUTOLOGOUS HEART VALVE (BIOVALVE): SCAFFOLDDESIGN, PREPARATION METHOD AND PERFORMANCEK. Hayashida1,2, H. Huang1, K. Kanda2, H. Yaku2, Y. Nakayama1. 1Depart-ment of Bioengineering, National Cardiovascular Center Research Insti-tute, Osaka, 2Department of Cardiovascular Surgery, Kyoto PrefecturalUniversity of Medicine, Kyoto, JapanBackground: We attempt “in body tissue architecture” technology based ontissue-encapsulation mechanism to prepare several autologous tissues forimplantation as a new concept of regenerative medicine. For example, func-tional autologous vascular tissues were successfully produced in animals’bodies. In this study, as an extension of the technology, trileaflet heart valvesconsisting of autologous connective tissues with polymeric support scaffoldswere developed. Materials and Methods: Crown-shaped compliant microp-orous polyurethane (PU) tubes (5–20 mm in internal diameter) with 3notches were specially designed as scaffolds for valves. The scaffolds, someof which were reinforced by metallic stents, were inserted with silicone rodsand then implanted into dorsal subcutaneous pouches of Wister rats or NewZealand White rabbits for 4 weeks. Formed tissues were examined histo-logically and mechanically. The function of the valvular tissue was evaluatedunder a pulsatile flow loading circuit in vitro. Results: Upon implantationuniform thin films of connective tissues were formed as three leafletsbetween the 3 notches of the PU crowns in each size of the scaffold in bothanimals. The leaflets mostly consisted of collagen-rich extracellular matri-ces and fibroblasts, and tightly connected to the PU scaffold, interstices ofwhich were occupied by similar tissues. The tensile strength of the leafletswas equivalent to that of porcine aortic valve. Under the flow circuit (ret-rograde pressure: 50 mmHg), good coaptation of three leaflets withoutmajor regurgitation was observed. Conclusion: Autologous “BIOVALVES”were produced in animals’ bodies. Implantation of the designed PU scaf-folds automatically induced functional valvular tissue formation withoutany complex cell processing and assembling. They can be ideal valves withgrowth ability and no immunological rejection.

O 075 NON EQUILIBRIUM O2-DISSOCIATION CURVES (ne-ODC):EFFECT OF PCO2, SHEAR RATE AND HEMATOCRITS. Salimi, A. Henseler, K. Mottaghy. Department of Physiology RWTHAachen University Hospital, GermanyAim: Blood gas transfer is a dynamic process depending on the relationshipbetween O2-saturation and Po2 as well as further physical and biochemicalparameters. Blood gas status is conventionally delivered by laboratoryanalysis of blood samples. However, this method is a static procedure underequilibrium conditions. Therefore it can not reveal the dynamic propertiesof the in vivo situation with a contact time of <0.5 s. We recently demon-strated the principle applicability of our new device generating ne-ODCunder defined shear rates and blood gas contact time. Here we report onthe effect of Pco2, shear rate and hematocrit, which are important physio-logical parameters in connection with the relationship between Po2 and O2-saturation. Methods: The shear flow is realized by means of two co-axialcylinders. The shear rate of blood in the gap between the two cylinders isset by rotational speed of the inner cylinder and gap width and radii of bothcylinders. The outer cylinder is gas permeable. At the top of the gap twosensors register the O2 status continuously: Po2 electrochemically and O2-saturation by means of two wave length laser diodes. The course of Po2 andO2-saturation as a function of contact time of blood and oxygen is regis-

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tered continuously, allowing the plot of the non equilibrium O2-Dissocia-tion Curves for a chosen contact time. Results: Results show that increaseof shear rate has a significant influence on the O2-saturation as a functionof time up to shear rates of 500 s-1. Changes of Pco2 cause a less emphasizedright shifting as it is known from the usual O2-Dissociation Curve underequilibrium conditions, especially for Pco2-values <50 mm Hg. Lower hema-tocrit values e.g. Hct = 25% lead to shorter oxygen saturation times thanhigher values. Conclusion: These results demonstrate again the fact that thene-ODC delivers relationships and effects, which can not be obtained withusual O2-Dissociation Curves, since this new method considers additionallythe deformability of red blood cells under physiological shear flow condi-tions. Therefore the ne-ODC should be preferred towards the steady stateODC, so that the different influences on O2-saturation can be evaluated ina more physiological way, thus it would be more suitable for clinical appli-cations e.g. in intensive care or for patients with RBC diseases.

O 076 THE SLIDEREACTOR—EVALUATION OF A HOLLOWFIBER BASED BIOREACTOR SUITABLE FOR LIGHTMICROSCOPYR. Schwartlander, J. Schmid, E. Katenz, X. Cheng, G. Pless, X. Gong,F. Vondran, P. Neuhaus, I.M. Sauer. Chirurgische Klinik, Charité Univer-sitätsmedizin Berlin, GermanyAim: Most bioartificial liver support systems are based on hollow fiber cap-illaries within modified dialysis cartridges or more sophisticated bioreactorconstructions. However, these systems are unsuitable for direct follow up ofre-organization or growth of liver tissue. Therefore little is known about thehistological course of the cells in these bioreactors. Aim of the study wasthe development and evaluation of a simple hollow fiber based bioreactorsuitable for light and video time-lapse microscopic observation. Methods:The SlideReactor is based on hollow fiber capillaries, silicone tubes withLuerLock-to-tube connectors providing access to the areas and silicone forassembling the parts. In order to enable cell adhesion, one slide consists ofadhesive cell culture plastic ware, for the top glass microscope slides areused. The system is gamma sterilised. The perfusion system comprises theSlideReactor, a medium reservoir with probe heads for continuous deter-mination of pH-, O2- and temperature levels, a circulation pump and a sil-icone tube oxygenator all situated in a heating unit. The SlideReactor wascharged with primary human liver cells and cell lines (HepG2, HuH7, C3A).During culture the cells were analyzed via time-lapse video microscopy.After culture termination and a first evaluation by phase contrastmicroscopy the cells were fixed, stained and analyzed by immuno-fluores-cence microscopy. As control, cells were cultured in standard monolayertechniques. Results: The experiments show the feasibility of this concept:The SlideReactor’s cell compartment is ideal for video time-lapsemicroscopy of the different cell types. Cell divisions, movement and growthof the cells can be recorded. Morphology as well as growth was compara-ble to the controls, regarding the cell lines even better. The performedimmuno histology proved the viability and functionality of the cells. Actinfilaments, cytokeratines and nuclei showed normal structural appearance.Conclusion: The SlideReactor may serve as simple tool to evaluate the cell-to-cell and cell-to-hollow fiber interaction. The device enables characteri-zation of cell behaviour under controlled conditions and analysis of theinfluence of several parameters on the cell viability and tissue integrity.

O 077 EVALUATION OF BIAXIAL CELL STRETCHING DEVICEFOR CARDIOVASCULAR TISSUE ENGINEERINGA. Szentivanyi, G. Rau, B. Glasmacher, M. Klein*, A. Ghodsizad*.Helmholtz-Institute for Biomedical Engineering, RWTH Aachen Univer-sity and *University Hospital DuesseldorfBackground: Cardiovascular tissue engineering relies on physiologicalmechanical stimulation for correct phenotypic differentiation of culturedcells. In order to simulate the cardiovascular environment in vitro, a devicefor applying physiological cyclic tensile strains to cell cultures has beendeveloped and built. The strain field generated by this device has been char-acterized using surface marker imaging techniques as well as in cell cultureexperiments. Methods: Microvasular endothelial cells (CDC:HMEC-1)were cultured to confluent monolayers on hydrophilized and collagencoated silicone substrates and strained for up to 144 hrs. at 11% averagetensile strain. Endothelial cell response to strain and fluid shear stress wereseparated by selective disruption of the actin-/microtubule cytoskeleton.Cell orientation in the monolayer was visualized by PFA fixation and sub-sequent silver nitrate staining. For more detailed analysis of the tensile

strain field, actin cytoskeleton morphology was visualized by rhodamine-phalloidin staining. Results: Analysis of the generated strain field delineatedseparate areas of uniaxial and biaxial strain on the silicone membrane. Fluidshear stresses were found to be turbulent over most of the membranesurface and elicited no significant reorientation of cells. Conclusion andOutlook: The cell straining device developed and built at the HelmholtzInstitute is thus suitable for application in cardiovascular tissue engineer-ing. In a second stage, the cell stretching device will be fitted with a modulefor applying an additional pulsatile pressure profile synchronized with theapplied strain field.

O 078 BONE TISSUE ENGINEERING: COMBINATION OF MESENCHYMAL STEM CELLS (MSCs) AND NOVEL 3DALINATE/GELATIN/b-TCP HYBRID SCAFFOLDSY. Mohammadi1, H. Mirzadeh2, F. Moztarzadeh3. 1Biomaterials Department,Iran Polymer and Petrochemical Institute (IPPI),Tehran, 2Biomedical Engi-neering Department, Amirkabir University of Technology, 3Materials andEnergy Research Center, Tehran, IR IranBackground/Aim: Increasing demand for bone graft materials and the prob-lems associated with available graft materials continues to stimulate bonegraft materials research. In Tissue Engineering, an appropriate scaffold pro-vides a solid framework for cell attachment, migration, differentiation, andproliferation, so acts like natural extra-cellular matrix (ECM). Bioceramics,as well as synthetic and natural polymers which are associated with cellgrowth and adhesion have been used as matrices for bone tissue engineer-ing. In order to imitate the natural bone, in the present work novelbiodegradable 3D polymer/ceramic constructs were developed and the pro-liferation and osteogenic differentiation of the incorporated MSCs wereexplored. Methods: In this study, based on a biomimetic approach, algi-nate/gelatin/b-TCP composite scaffolds were fabricated by solid-liquidphase separation and a subsequent freeze-gelation process. In vitro, rat-MSCs were seeded in the hybrid scaffolds for 42 days and the osteogenicpotential of these matrices was characterized by histology, ALP, MTT assayand SEM observations. Moreover, in vivo assays were performed by implan-tation of proper acellular scaffolds on sheep femur. Results: The compositescaffolds created in this study exhibited a highly interconnected macrop-orosity, with a macropore size of 200–500 mm and over 85% porosity. More-over, increasing b-TCP resulted in improving mechanical properties andenabled cells to show the highest cell number and ALP activity whilst themorphology of scaffolds became heterogeneous. Conclusions: The resultsindicated the benefits of using aforementioned materials as tissue engi-neering scaffolds for the regeneration of new bone. Furthermore, Rat MSCswere successfully incorporated with a high cell density in the scaffolds,remained viable for an extended period of time, proliferated extensively,and showed evidence of osteogenic differentiation.

Organ Transplantation

O 079 COMPARATIVE STUDY OF THE HYPOTHERMIC PRESER-VATION AND PULSATILE PERFUSION EFFECTS IN AUTO-TRANSPLANTED ISCHEMIC KIDNEYSI. Berenguer*, G. Pedemonte, D. Rodríguez-Martínez*, A. Alvarado**,C. Martinez***, J.F. Del Cañizo*, E. Lledó-García. Urology Dept. HospitalGeneral Universitario Gregorio Marañón. *Experimental Medicine &Surgery Dept. Hospital Gregorio Marañón. **Pathology Dept. HospitalGregorio Marañón. ***Pharmacy Service. Hospital Gregorio Marañón.Madrid, SpainAim: To evaluate the hemodynamical consequences in autotransplantedischemic kidneys which have been either cold-storaged or perfused with aself-designed vacuum pump. Methods: 16 Minipigs (25–35 kg) were usedand divided in four groups: Group A (n = 4) nephrectomy + autotransplant,Group B (n = 4) 45 minutes of warm renal ischemia + nephrectomy + auto-transplant, Group C (n = 4) 45 minutes of warm renal ischemia + 60 minutesof hypothermic conservation in UW Viaspan at 4°C + nephrectomy + auto-transplant, and Group D (n = 4) 45 minutes of warm renal ischemia + 60minutes of pulsatile perfusion with Belzer at 4°C + nephrectomy + auto-transplant. Renal flow, perfusion pressure and renal vascular resistance wererecorded on real-time during 60 minutes by means of flow and pressuretransducers applied to the renal artery. All the procedure was controlledand registered by a computer system. Results: There seem to be a tendencyto obtain lower values of renal vascular flow and higher values of renal vas-cular resistance in ischemic kidneys in relation to their non-ischemic coun-

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terparts. Pulsatile hypothermic perfusion was related to better dynamicpost-transplant results in comparison to cold storage, but by the time theseresults are not still significant. Conclusion(s): Our pulsatile cold perfusionsystem seems to be a better preservation method in ischemic kidneys. More-over, it could be used as a evaluation system of the organ microvascularquality. Warm ischemia seems to produce an important deleterious in organsfor transplant.

O 080 COMBINED LIVER KIDNEY TRANSPLANTATION: S.ORSOLA EXPERIENCEG. Mosconi, M.P. Scolari, G. Feliciangeli, G. Liviano, D. Arcangelo, A. Bus-caroli, F.D. Addio, A. Faenza°, A.D. Pinna*, S. Stefoni. Nephrology, Dialy-sis, Renal Transplantation Unit—*Liver and Multivisceral TransplantUnit—°Renal Transplantation Surgery Unit -S.Orsola University Hospital,Bologna, ItalyBackround: Combined liver kidney transplantation (LKT) has the poten-tial to provide a complete recovery of both liver and kidney organ failure.Literature reports an increase in LKT in the last few years and an improve-ment in patient and graft survival. Our aim is to evaluate our experience.Results: Fifteen patients underwent LKT from 1997 to 2005. The averageage at the time of LKT was 50 ± 9 years (range 34–63 years). The patients(pts) were affected by a viral (9), alcoholic (1), polycystic (2), cholangitis (1),cholestatic (1) or amyloidotic (1) chronic hepatopathy. Chronic renal failurewas due to a polycystic kidney disease (4), IgA nephropathy (2), Intersti-tial nephropathy (2), glomerulonephritis (4), amyloidosis (1), vascularnephropathy (1), ESRD (1). Twelve pts were on RDT, 3 pts had mild tomoderate chronic renal failure. Two pts had previously been transplanted(kidney), two other pts were polytransfused. All the pts were selected byblood group identity and a crossmatch before transplantation was per-formed. Histocompatibility matching (HLA) was not included in the selec-tion criteria. No case of delayed graft function was observed. The meanfollow up was 23 ± 32 months (range 1–99 months). Only one patient hadan episode of acute rejection in the first year. At the moment twelve ptsshow normal hepatic and renal function. At the beginning of our experiencetwo pts in bad clinical condition died within one month because of septi-caemia and pulmonary infection. One patient died because of a pulmonarymalignancy after 7 years; in the three pts deceased both liver and kidneywere functioning well. Discussion: Our results, as in the literature, confirmthe efficacy of LKT. Incidence of allograft rejection was less than 10%, sig-nificantly lower than that reported for isolated kidney transplantation. Weobserved that good nutritional status seems to prevent surgical and earlyinfectious complications. It is important to assess experience in order tooptimize the efficacy of LKT.

O 081 THE EVOLUTION OF UNTREATED SUBCLINICAL ANDBORDERLINE REJECTIONS AT FIRST MONTH KIDNEY ALLO-GRAFT BIOPSY IN COMPARISON WITH HISTOLOGICALCHANGES AT 6 MONTHS PROTOCOL BIOPSIESJ. Masin-Spasovska1, G. Spasovski1, S. Dzikova1, G. Petrusevska2,B. Dimova2, L. Lekovski3, Z. Popov3, N. Ivanovski1, M. Polenakovic1. 1Dept.of Nephrology, 2Dept. of Pathology, 3Dept. of Urology, University of Skopje,MacedoniaAim: The aim of our study was to identify subclinical and borderline rejec-tions (SR/BR) and histological markers of chronic allograft nephropathy(CAN) and their possible impact on graft function. Methods: 28 pairedkidney allograft biopsies at 1 and 6 months were reviewed according to theBanff scoring scheme. Serum biochemistry was taken at scheduled intervals.Results: At first month BR was shown in 32% and SR in 10% of the patients.At 6 months the proportion of these findings was 21% and 36%, respec-tively. The mean CAN score (sum of histological markers for chronicity)increased significantly at 6 months biopsy, 1.57 ± 1.36 vs. 4.36 ± 2.32 (p <0.01). When divided according to the donor’s age (<55> years), older donorsgroup had mean CAN score of 1.58 ± 1.35 which increased to 4.68 ± 2.08 (p < 0.05) at 6 months biopsy. At 6 months biopsy the proportion of patientswith BR and SR was significantly higher in older donor group in compari-son with the younger donors group 13/19 (68.4%) vs. 3/9 (33.3%). Thegroups differed significantly in calculated creatinine clearance (cCrcl) at 6months, what was not the case at first month. When compared according tochronicity index (CI<5>), i.e. the sum of the total scores at 1-month biopsy,BMI and GFR of the donors in the low CI group was significantly higherand the donors tended to be younger. There was a higher number ofepisodes of AR in high CI group 8/14 (57.14%) in comparison with the low

CI group 2/14 (14.28%). High CI group had mean CAN score of 2.36 ± 1.15at 1 month, which increased to 5.14 ± 1.99 at 6 months biopsy (p = 0.01). Inlow CI group the proportion of these changes have also been increased from0.79 ± 1.12 to 3.57 ± 2.38, p = 0.02 at 6 months biopsy. Conclusion: Onemonth biopsy may be valuable for determining of BR/SR and its possibleimpact on the outcome of the renal allograft function. Our findings suggesthigher susceptibility for histological deterioration in older donors popula-tion. However, the presence of an untreated BR and SR in the youngerdonors pool leads to a rapid impairment of the graft function throughoutan accelerating process of chronic allograft nephropathy.

O 082 THE IMPROVEMENT OF IMMUNOLOGIC FUNCTION IN DIABETIC MICE AFTER LANGERHANS ISLETS XENOTRANSPLANTATIONE. Godlewska, M. Antosiak, T. Orlowski. Institute of Biocybernetics andBiomedical Engineering, Polish Academy of Science, Warsaw, PolandAim: The immune function in diabetes mellitus is abnormal. Autoagressionagainst pancreatic islet cells is present and immune response to foreign anti-gens is weak. Normalization of carbohydrate metabolism by exogenousinsulin or by islet allotransplantation improves these defects. To provewhether xenogenic Islet grafts may also be effective appropriate experi-ments were preformed. Results obtained in healthy animals. Methods: Theskin graft survival in BALB/c mice with streptozotocin diabetes were esti-mated during: 1) diabetic hyperglycemia and 2) euglycemic period, inducedby i.p. transplantation of 1000 WAG rat islets encapsulated according to SunAPA method. The recipients were divided in following groups: A) naivehealthy mice (control): 8 transplanted twice with WAG skin grafts (NSS); 8transplanted with WAG free islets followed by skin graft (NIS); and B) dia-betic mice: 20 transplanted twice with WAG skin grafts (DSS); 7 trans-planted with WAG free islets followed by skin graft (DIS); 13 transplantedwith encapsulated WAG islets followed by skin graft (DES).The length ofthe second skin graft survival served as criterion of the degree of hostimmune response. Results: In group DSS the survival time (days) of boththe 1st (8.5 ± 0.5) and the 2nd (7,3 ± 0.4) skin grafts were longer than ingroup NSS (7.8 ± 0.9; 5,5 ± 0.8). The period of euglycemia in group DISanimals was short (5.2 ± 2.0 days) and graft survival of skin transplantedduring recurrence of hyperglycemia (8.5 ± 0.19) was the same as in groupDSS recipients. Diabetic mice transplanted with encapsulated islets devel-oped long-lasting normoglycemia and no difference was found between sur-vivals of skin transplanted in groups NSS and DES (5.9 ± 0.14). Conclusion:Successful transplantation of APA encapsulated islet xenografts successfullyrestored not only euglycemia, but also immune response of host to skinxenografts.

Polymers and Scaffolds

O 083 HET-CAM TESTING COMBINED WITH HISTOLOGY: ARAPID AND SIMPLE METHOD FOR BIOMATERIAL SELECTIONC. Eder1,2, E. Falkner2,3, H. Schöffl2, S. Nehrer1, UM Losert3. 1Dept. ofOrthopaedic Surgery, Medical University Vienna, 2zet-Centre for Alterna-tive and Complementary Methods to Animal Testing, Linz, 3Core Unit forBiomedical Research, Medical University Vienna, AustriaIntroduction: The HET-CAM (Hen Egg Test-Chorionallantoic Membrane)test has originally been validated for toxicity and irritation studies and isunder increasing attention for biomaterial evaluation purposes. The highvascularity of the CAM and the rapid development of connective tissue andvessel system offer an interesting environment for tissue reaction studies.Materials & methods: Various biodegradable scaffolds were applied ontothe CAM on incubation day 7 and maintained in ovo for 3 days prior todigital documentation, macroscopical biocompatibility evaluation and sub-sequent histological analysis. A collagen sponge, two different CollagenType I/III scaffolds (Chondro-Gide, Bio-Gide) and a Collagen Type II mem-brane (Chondrocell) were tested. Results: Collagen sponge: Macroscopicanalysis demonstrated extreme rapid degradation, spontaneous bleedings inthe surrounding of the implant and a vessel retraction from the implanta-tion site. Histological analysis showed a foreign body control. Chondro-Gide: Macroscopic evaluation showed excellent integration andbiocompatibility patterns which were confirmed by histology. A tissue reac-tion was not observed and the scaffold showed excellent angiogenetic prop-erties. Bio-Gide: Macroscopic observation showed excellent integration andsignificant induction of angiogenesis, which was confirmed by histology. Aninflammatory infiltrate was observed. Chondrocell: Macroscopic evaluation

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showed good integration of the biomaterial, which was confirmed by his-tology. Histological evaluation demonstrated good biocompatibility pat-terns, the absence of an inflammatory infiltrate and good angiogeneticproperties. Conclusions: Applying a biomaterial to the chorionallantoicmembrane allows the evaluation of tissue integration, angiogeneticresponse and tissue reaction to the implant, allowing a rapid and cheap com-parison of different biomaterials and facilitating biomaterial selection for invivo experimentation.

O 084 BIODEGRADABLE HYBRID SCAFFOLDS WITH INTER-CONNECTED NETWORKS FOR BONE TISSUE ENGINEERINGY. Mohammadi1,2, H. Mirzadeh1,2*, F. Moztarzadeh2,3, E. Jabbari4.1Biomaterials Department, Iran Polymer and Petrochemical Institute(IPPI), 2Biomedical Engineering Faculty, Amirkabir University of Tech-nology, 3Materials & Energy Research Center, Tehran, Iran, 4Department ofChemical Engineering, University of South Carolina, Columbia SC, USAAim: Although major progresses are made in the field of bone regenerativemedicine in the last few years, current therapies, i.e. autografts, allograftsand synthetic materials still have several limitations. In bone tissue engi-neering (BTE), however, a scaffold prolongs the cell survival, providesinitial mechanical stability, supports tissue ingrowth, and assists in tissuestructure formation and ultimately it must be replaced by a regeneratedextracellular matrix to form a normal and completely natural bone tissue.Hence, it is obvious that an appropriate 3D scaffold should be an essentialcomponent for a BTE strategy. Methods: In this work, a novel 3Dbiodegradable porous hybrid biomaterial consisting of poly(lactide-co-gly-colide) (PLGA), b-tricalcium phosphate (b-TCP, an osteoinductive biore-sorbable bioceramic), and chitosan (CS, an osteoconductive biodegradablenatural polymer) was developed. Macroporous PLGA/b-TCP scaffoldswere prepared by combining PLGA and b-TCP cement particles with sagercrystals as porogen through the process of freeze-extraction/particulateleaching. Afterwards, the macroporous PLGA/b-TCP scaffolds were im-mersed in the CS/b-TCP aqueous solution under vacuum. The CS solution-containing PLGA scaffolds was frozen to induce solid-liquid phaseseparation and then freeze dried to completely remove the solvent andenable the formation of CS/b-TCP sponges in the pores of PLGA/b-TCPscaffolds. Results: Our results showed that the prepared scaffolds are highlyporous, with porosities larger than 80%, and have interconnected pores.Moreover, the microstructure of the composite scaffolds could be easily controlled by varying the concentration of PLGA and/or CS solutions,the content of b-TCP, the size of the porogen crystals, and the quenchingtemperature. Conclusion: In vitro evaluations revealed that the compositescaffolds have good biocompatibility. The PLGA/CS/b-TCP hybrid net-works would serve as useful 3D porous scaffolds for BTE.

O 085 CHARACTERISATION OF THE BIODEGRADATION OFMAMMALIAN SILICONE-PROSTHESESA. Janke1, N. Unbehaun2, L. Kovacs2, B. Glasmacher1. 1Helmholtz-Institutefor Biomedical Engineering, Aachen, 2Department for Plastic Surgery,Munich, GermanyBackground: Although there are doubts about the reliability of siliconebreast implants, plastic surgery is still the trend. Problems like the buildingof a fibrous capsule, inflammation, skin redness or even bleeding and realrupture of the implants are common. The influence of implantation time onthe biodegradation of the material is not yet cleared, but diffusion of notcross-linked silicone oligomers and lipid infiltration play a decisive part init. Methods: The study is based on the investigation of 99 explanted siliconemammalian prostheses of 8 different manufacturers with an implantationperiod between 3 months and 36 years. Textured and smooth prostheseswere filled with silicone gel, saline and sojaoil. Up to now, 67 explanted sil-icone breast prostheses were analysed according to ASTM 703-96 andASTM 1708-79. 11 native silicone gel-filled textured implants of a particu-lar manufacturer were used as reference materials. An additional extractivepre-treatment of samples was added, to take into account a possible siliconediffusion or lipid infiltration. Results: The results of the tensile tests showeda slight decrease in tensile strength and elongation at break with texturedimplants. Smooth surface implants exhibited a more indefinite behavior. Acorrelation between state of the implant with explantation or degree offibrous capsules was not found. The amount of extractable substances is with17.3% remarkably higher for smooth implants compared to 8.3% for tex-tured prostheses. Thermal and chemical analysis of the extracts is subject ofstill ongoing tests.

O 086 REPLACEMENT OF THE RAT AORTA WITH FULLYDEGRADABLE SYNTHETIC VASCULAR PROSTHESISM. Cikirikcioglu1, G. Bowlin3, Y.B. Cikirikcioglu1, J.-C. Tille2, J.-C. Pache2,A. Kalangos1, B.H. Walpoth1. 1Department of Cardiovascular Surgery,University Hospital, Geneva, 2Department of Clinical Pathology, UniversityHospital, Geneva, Switzerland, 3Biomedical Engineering, Virginia Com-monwealth University, Richmond, VA USABackground/Aim: Vascular tissue engineering necessitates degradablematerials as scaffold. Our purpose was to evaluate biocompatibility andthrombogenicity of biodegradable poly-dioxanone (PDS) grafts in the rataorta replacement model. Methods: PDS was chosen as material after thefollowing screening steps: Biomechanical strength, surgeon’s handling,degradation, cell ingrowth and tissue reaction in the rat subcutaneousimplantation model. All PDS grafts were manufactured by electrospinning.In 15 Sprague Dawley rats, 1 mm ePTFE grafts (n = 6) and 1 mm PDS grafts(n = 9) [bare,external wrapped or mixed with slow degradable poly-lacticacid (PLA)] were interposed in the infrarenal abdominal aorta. The proxi-mal and distal anastomoses were performed with 10/0 interrupted nylonsutures using an operative microscope. Patency was assessed with intraop-erative transit time flow measurement. At conclusion of the study, digitalsubstraction angiography was performed and grafts were harvested for mor-phologic as well as scanning electron microscopic examination. Results:After three weeks of implantation, PDS showed comparable patency rates(overall, 89%) to ePTFE grafts (83%). However, saccular aneurysm for-mation was found in all unwrapped patent PDS grafts. This was preventedwith external wrapping (in 3 animals grafts were wrapped with non-degrad-able woven matrix, ePTFE or external nylon electrospinning) or combina-tion of PDS with PLA (n = 3). Conclusions: The patency rate at 3 weeks ofelectrospun PDS 1 mm grafts was 87% and comparable to ePTFE grafts(83%). However, if the prosthesis was manufactured with only biodegrad-able PDS, aneurysm formation was seen in all cases. This could be preventedby external wrapping or combining PDS with PLA. Thus, PDS-based poly-mers may be promising materials for vascular tissue engineering.

PATENCY ANEURYSM(3 WEEK) FORMATION

Native ePTFE (n = 6) 5/6 0/6

Bare PDS (n = 3) 2/3 2/2

External supported PDS (n = 3) 3/3 0/3

PDS mixed with PLA (n = 3) 3/3 0/3

Symposium Tissue Engineering

O 087 IN VITRO CARDIOMYOCYTE DIFFERENTIATION OFAMNIOTIC FLUID STEM CELLSS. Bollini1,A. Chiavegato2, M. Pozzobon1, M. Piccoli1, E. Slanzi1, F. Castello1,G.M. Zanon3, M. Carli1, S. Sartore2, P. DeCoppi1,3. 1Stem Cell ProcessingLaboratory, Department of Pediatric Oncohematology, University ofPadua, 2Experimental Biomedical Science Department, University ofPadua, 3Division of Paediatric Surgery, University of Padua, Padova, ItalyBackground and Aim: Amniotic fluid represents a new attractive source ofstem cells for cellular therapy applications. Isolation of amniotic fluid stemcells (AFSCs) is easy to perform and can be obtained by widely acceptedprenatal diagnosis method. AFSCs show low immunogenecity, clonogenicand self-renew properties and are pluripotent in vitro and in vivo. The aimof this study was to assess AFSC cardiomyocyte differentiating potential invitro. Methods: Human AFSCs were isolated from amniocentesis samplesfollowing informed consent; rat GFP-positive AFSCs were obtained fromGFP-transgenic pregnant Sprague-Dawley rats. AFSCs were immunosortedfor the expression of stem cell antigen c-kit and then co-cultured in vitrofor 10 days with neonatal cardiomyocytes isolated by 2/3-days old Wistarrats. hAFSC were labelled with fluorescent intracellular marker CMFDA.Cells were analyzed at 4-7-10 days for GFP/CMFDA and sarcomeric struc-tural proteins, such as troponin I, expression by immunofluorescence.Co-cultured hAFSC were also analyzed by RT-PCR, using human cardiacspecific primers for GATA-4, NKX 2.5, MLC-2V and a-MHC genes.Results: After 4 days in co-colture, few rat and human AFSCs were foundinside cardiomyocyte beating areas showing contractile activity. Immunos-

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taining analysis revealed 5% of AFSCs expressing cardiomyocyte markerssuch as troponin I or MHC. At 4 days co-coltured hAFSCs showed mRNAexpression for cardiac transcriptional factors GATA-4 and NKX 2.5 and sar-comeric proteins MLC-2V and a-MHC. Conclusions: Human and rat AFSCshowed the potential to differentiate into cardiomyocytes in vitro. Furtherstudies are necessary to improve the low efficiency of differentiation processand to explore the in vivo potential of AFSC.

O 088 PRODUCTION OF BIOLOGICALLY ACTIVE RECOM-BINANT HUMAN BMP-2 FOR TISSUE ENGINEERING APPLICATIONSP.C. Bessa1,2, A.J. Pedro1, M. Casal2, R.L. Reis1. 13B’s Research Group–Biomaterials, Biodegradables and Biomimetics, University of Minho,2Department of Biology, University of Minho, Braga, PortugalBackground/Aim: Bone morphogenetic protein-2 (BMP-2) is a powerfulcytokine with strong ability to induce bone and cartilage formation. In thiswork, we aimed to obtain human recombinant BMP-2 in a soluble, pure andbiologically active form by means of developing a new and simple bacteriaexpression system. Methods: The sequence coding for mature rhBMP-2 wascloned in a pET-25b vector and expressed in BL21DE3 E. coli strain. Theprotein was obtained soluble and further purified by high affinity chro-matography. Biological activity was preliminary characterized by alkalinephosphatase activity (ALP), MTS cell viability test and Van Kossa staining,after 1 and 2 weeks of cell culture using 2 different mesenchymal stem cellprimary cultures. Results: Recombinant BMP-2 was purified to a degree ofmore than 95%. Yields were of around 60 mg/L shake flask. The purifiedprotein showed biological activity as levels of ALP activity were significantlyincreased and changes in morphology could be clearly observed. Prelimi-nary Van Kossa staining also shows indication of bone mineral node for-mation. Conclusion(s): The new method presented herein shows to be a promising way for obtaining large yields of active rhBMP-2 which may be useable for diverse tissue engineering applications. Knowledgments:Portuguese Foundation for Science and Technology for the PhD grantSFRH/BD/17049/2004; European STREP Project HIPPOCRATES(NMP3-CT-2003-505758). This work was carried out under the scope of theEuropean NoE EXPERTISSUES (NMP3-CT-2004-500283).

O 089 IN VIVO STEM CELL SEEDING OF SYNTHETIC VASCU-LAR GRAFTSM. Cikirikcioglu1, S. Yang1, J.C. Tille2, A. Kalangos1, B.H. Walpoth1.1Department of Cardiovascular Surgery, University Hospital, Geneva,2Department of Clinical Pathology, University Hospital, Geneva,SwitzerlandBackground/Aim: Patency of small synthetic grafts is inferior to autologousgrafts, mainly due to missing endothelialisation. Multi-potent bone-marrowstem-cells (BMSC) have shown to differentiate into endothelial cells. Ouraim was to assess the safety and efficacy of intra-operative BMSC trans-planted on ePTFE grafts. Methods: Sixteen syngenic Sprague-Dawley rats(350 g) were used as BMSC donors (n = 8) and cell-seeded vascular BMSCgraft recipients (n = 4), as well as controls (n = 4), receiving only the un-seeded ePTFE graft. BMSC were isolated, labelled and immediatelyinjected in the ePTFE graft. Seeded and control grafts were implanted inthe rat infra-renal aorta. Animals survived for 3 weeks and patency wasassessed by angiography. Histology and frozen sections were performedafter DAPI nucleus staining to quantify the transplanted BMSC. Neo-endothelialization was evaluated by morphometry. Results: From eachdonor, a mean of 5 Mio marked cells were obtained (FACS) and immedi-ately injected into the graft. After BMSC injection scanning electronmicroscopy and histology showed transplanted cells in the superficial layersof the graft. At conclusion of the study, patency rate was excellent (100%)and similar in the seeded and un-seeded grafts. Macroscopically, a mild peri-graft inflammation was found in the cell-injected grafts. The neo-endothe-lialization was low and similar in both groups. More cellular ingrowth wasfound in the BMSC grafts and transplanted cells were found after 3 weeks.Conclusions: Intraoperative bone-marrow stem-cell seeding of a syntheticporous vascular graft is safe since no thrombosis or immunologic reactionswere seen. The transplanted, labelled BMSCs were present in the graft after3 weeks of implantation and efficacy may be related to the number andapplication of the transplanted cells. Thus, this one-step procedure has to befurther evaluated for vascular graft seeding with autologous bone-marrowstem-cells in man.

O 090 TISSUE ORGANIZATION ACCELERATION TECHNOLOGYIN VIVO IN REGENERATIVE MEDICINE: A WING-ATTACHEDROD AS A NOVEL SCAFFOLD FOR “BIOTUBE” GRAFTS FABRICATIONO. Sakai1,2, Y. Zhou1, A. Ametani3, K. Kanda2, H. Yaku2, Y. Nakayama1.1Dept. of Bioengineering, National Cardiovascular Center Research Insti-tute, Osaka, 2Dept. of Cardiovascular Surgery, Kyoto Prefectural Universityof Medicine, Kyoto, Japan, 3Medical Device Group, Nippon Cable SystemInc. Hyogo, JapanBackground: Recently we developed functional autologous vascular tissues(BIOTUBEs) in animals’ body by “in body tissue architecture” technologyunder the new practical concept of regenerative medicine. However, it tookmore than 3 months to form reliable tissues for implantation. In this study,“wing-attached rods” were designed as novel scaffolds to accelerateBIOTUBE fabrication. Materials and Methods: Two kinds of scaffolds wereconstructed. One was composed of a silicone (Si) rod (3–6 mm in diameter,20 mm in length) partly connected with one poly(ethylene terephthalate)film (20 ¥ 10 mm) as a “wing”. Another was a Si rod with two wings con-nected by 180 degrees. The scaffolds were implanted into dorsal subcuta-neous pouches of Wister rats or New Zealand White rabbits. After twoweeks, the scaffolds encapsulated by thin hom*ogeneous tissues were har-vested. After removal of “wings”, connective tissue membranes formed onthe wings were rolled up and laminated on the tubular tissues formedaround the Si rods. The assembled tissues were re-implanted in subcuta-neous pouches of the same animals for another 2 weeks. Results: Afterprimary implantation, the thickness of formed connective tissues mostlyconsisting of collagen and fibroblasts was less than 100 mm. Upon secondaryimplantation, laminated tissue membranes were tightly connected withtubular tissues around the Si rods. Histological investigation revealed thatthe tubular tissues were full of angiogenesis between the volute layers.Spindle shaped cells were regularly oriented in circumferential directionjust like native vascular tissues. Rapture strength was over 2000 mm Hg.Conclusion: By designing the scaffold shape (wing-attached rod) and devel-opment of fabrication method (tissue rolling), “BIOTUBE” fabricationprocess was significantly accelerated. The finally obtained tubular tissueswithin 1 month were thicker and stronger than those formed on simple Sirods after 3 months of implantation.

O 091 TISSUE ENGINEERING IN VITRO: DIFFERENTIATION OFSTEM CELLS TO CARDIOMYOCYTESL.L. Lukash, D.A. Bazika, N.V. Belyaeva, O.A. Kovalenko, O.V. Pidpala,A.P. Yatsishina. Institute of Molecular Biology and Genetics of NationalAcademy of Sciences of Ukraine, Ukrainian Center of Radiation Medicineof Health Ministry of UkraineAim: The purpose was obtaining of pluripotent mesenchyme stem cell linesand cardiomyogenic differentiation of progenitor cells in vitro. Methods:Primitive progenitor cells with good growth properties have been isolatedfrom fetal and adult tissues of human and murine origin of different age.Then six mesenchyme-like cell lines have been established. We obtainedmuscle cells with a help of method of direct differentiation at complex com-bination of growth factors and conditioned medium. Results: We haveshown the differentiation of human and mouse mesenchyme-like cells tomuscle cells with high efficiency. According to immunophenotyping mem-brane anti-smooth muscle antigen A144+ was present on the cellular surfacein more than 80% of cells from the probes after cardiomyogenic inductionas well as in the mixed cell population isolated from heart tissue. At specialconditions areas with spontaneous rhythmical contractile activity have beenobserved. The rhythms of beating in the medium with calcium were differ-ent and regularly slower than in vivo. Conclusions: Establishment of a car-diomyocyte differentiating system may become a tool for understandingcardiac development and function. The variations between human andmurine model may represent the differences between the species, the celllines and some yet undetermined factors. Another attractive application ofthose cells is cellular cardiomyoplasty as a new therapeutic strategy ofcardiac insufficiency.

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O 092 LPS-INDUCED GENE EXPRESSION IN HUMAN MONO-CYTES AND ENDOTHELIAL CELLS IN AN EXPERIMENTALMODEL FOR GRAM-NEGATIVE SEPSISK. Hellevuo1, E. Rossmanith1, E. Knapp2, D. Klein2, D. Falkenhagen1.1Center for Biomedical Technology and Christian Doppler Laboratory forSpecific Adsorption Technology in Medicine, Danube University Krems,2Institute of Virology, University of Veterinary Medicine, Vienna, AustriaBackground: Adsorptive extracorporeal therapy is a treatment option forpatients suffering from sepsis and multi-organ failure. Identification ofpathophysiological mediators is a prerequisite for successful therapy devel-opment. We have developed a cell culture-based model for sepsis in orderto identify potential targets for specific adsorption therapy. In this study, weinvestigated gene expression changes in THP-1 cells (human monocyte cellline) and HUVECs (human umbilical vein endothelial cells) induced byendotoxin (LPS), the major component in Gram-negative bacteria. The aimwas especially to identify mRNAs that code for secreted proteins. Methods:The cells were stimulated by 10 ng/ml of LPS in the cell culture model. LPS-induced changes in the mRNA profile of both cell types were analyzed usingoligo-based microarrays (10 K) in dye-swap experiments. The microarrayresults were confirmed with real-time PCR analysis. Bioinformatic analyseswere carried out to identify potential secreted proteins. Results: LPSinduced mRNA levels of several genes that are known to play a role inGram-negative sepsis, thus validating the experimental cell culture model.Interestingly, new potential mediators and adsorption targets were also dis-covered. Based on sequence analysis, the gene products of the identifiedmRNAs are secreted proteins and related to complement cascades. Con-clusions: A cell culture-based model combined with microarray and real-time PCR analyses is a useful approach to identify novel mediators andpotential adsorption targets in Gram-negative sepsis.

Dialysis

O 093 THE PROCEDURE OF PROXIMAL ARTERIAL FEEDING:AN EFFECTIVE TREATMENT FOR ACCESS RELATED ISCHEMIAJ. Zanow, H. Scholz. Department of Vascular Surgery, Queen Elisabeth Hos-pital Berlin, GermanyBackground: Ischemia distal to an arteriovenous (AV) access for hemodial-ysis is a potentially devastating complication that can be difficult to manage.Recommended operative management includes ligation, banding and theincreasingly used distal revascularisation interval ligation (DRIL) method.We present procedure of proximal arterial feeding (PAF) as another option.Here the arterial inflow is proximalized by lengthening of the AV access tonext upper arterial level using a 4 or 5 mm PTFE graft. Methods: An exper-imental simulation of access related ischemia to compare the efficiency ofdifferent options for treatment was conducted. A silicone model of arterialsystem for the whole arm was made. This model was worked in an artificialcircuit filled with a glycerine water solution at blood viscosity. The simula-tion of an AV access, an distal ischemia characterized by defined distal arte-rial pressure (<40 mmHg) and flow (<15 ml/min), collateral flow to forearmand the different options for treatment was achieved. A simultaneous mea-surement of pressure and flow at different positions was possible. A reviewof clinical data and results of intraoperative measurements of PAF was per-formed. Results: Experimental study demonstrated the usability of theapplied model for the simulation of an access related ischemia. All simu-lated methods of treatment led to marked increase of distal pressure. ThePAF method was more effective to increase distal perfusion at an accessflow over 380 ml/min compared to the DRIL procedure. The increase ofdistal arterial pressure at PAF was less dependent on collateral flow. Duringlast six years we performed procedure of PAF in 29 cases. 83% had com-plete and 13% a substantial relief of ischemic symptoms. The primarypatency rate was 82% at 1 year. Conclusions: An useful model to simulateaccess related ischemia was established. Here the PAF demonstrated a clearbetter improvement of distal perfusion compared to DRIL method. Clini-cal results support the idea. The PAF is less extensive than DRIL procedureand does not sacrifice the natural arterial continuity.

O 094 BIDIALYSIS ON LINE: A NEW SOLUTION FOR IPERCATA-BOLIC OR HIGH BODY WEIGHT HEMODIALYSIS PATIENTSG. Splendiani, S. Condò, R. Colombo,A. Fierro, L. Nannini, C. Cucchi. Dept.of Nephrology Policlinico Tor Vergata, RomeBackground: We just experimented, in patients with high body weight, thesimultaneous use of two cuprophan hemodialyzers in sequence (DFS) in

hemodialysis, each one connected separately to fresh dialysate and we con-cluded that there was an advantage in urea clearance, osmolarity stabilityand reduction of side effects. The principal aims of this new study was, usingboth diffusion and convection technique, obtain an increase in soluteremoval, without side effects, the patient’s well being and without increaseof global costs. Methods: We used two hemodialyzers in sequence, each oneconnected separately to fresh dialysate, the first was a low flux polysulphone,the second was an high flux polysulphone with a reinfusion on line of 200 ml/min between the first and the second hemodialyzers. We studied tensymptomatic ipercatabolic patients with high body weight and comparedthe results to conventional haemodialysis. Results: After the first hemodia-lyzers modification of smalls molecules occurred in the plasma composition.In the second hemodialyzer, smalls molecules depuration continued and weobtained also a b2 microglobulin removal. The Kt/V increased from 1.11 to1.9 (79%). Conclusion: We conclude that Bidialysis on line is an advantagein blood purification and reduction of side effects in ipercatabolic or highbody weight patients.

O 095 IMPACT OF TEMPERATURE AND SOLUTE CONCENTRA-TION DIFFERENCES ON DIALYSATE PARTIONING IN THEGENIUS DIALYSIS SYSTEMS. Eloot1, A. Dhondt2, R. Vanholder2, P. Verdonck1. 1Institute of BiomedicalTechnology, Hydraulics Laboratory, Ghent University, 2Nephrology Section,Internal Medicine, Ghent University Hospital, BelgiumThe Genius single-pass batch system, containing a closed loop dialysatecircuit with a container of 75 L prepared and preheated dialysate, gains moreinterest and applications. In the container, fluid separation of spent andfresh dialysate is maintained during dialysis based on density differences.Because density is mainly determined by temperature and concentration,the present study was undertaken to investigate the relative contribution ofconcentration and temperature differences on dialysate partitioning. First,in vitro measurements were performed mimicking clinical dialysis and usingan open tank of 30 L dialysate to replace the patient. The density of spentdialysate was manipulated by varying the urea load in the fictitious patient,thus varying its solute content (g/L urea), and by warming it at the containerentrance (spontaneous cooling or heating until equal temperatures at con-tainer inlet and outlet). Solute concentrations were determined at the con-tainer inlet and outlet at different time points during in vitro dialysis, whiletemperatures were monitored continuously. Secondly, for a better under-standing of all impacting factors, numerical simulations (Fluent 6) were per-formed to visualize the variation of temperature and urea concentrationinside the container for the different in vitro tested dialysis sessions. Ureamixing in the container was enhanced for a spent dialysate temperatureapproaching the temperature of the fresh dialysate, and for lower urea con-centrations in the spent dialysate. Our numerical technique offers a betterinsight in the relative importance of the impacting factors determiningdialysate mixing, and allows predicting dialysis adequacy with therapiesdeviating from the standard 4 hours.

O 096 CLINICAL USE OF ARTIFICIAL HEART TECHNOLOGY TO PULSATILE PUMPS FOR LIFE-SUPPORT SYSTEM ANDHOME-DIALYSIS/FILTRATIONB.G. Min1,5, Y.S. Won2,5, K.K. Lee3,5, H.S. Son4,5, J.S. Shin4,5, K. Sun4,5. 1Dept.of Biomedical Engineering, Seoul National University, Seoul, 2Dept. of Tho-racic and Cardiovascular Surgery, Soonchunhyang University, Bucheon,3Dept. of Department of Veterinary Medicine, Cheju National University,Cheju, 4Dept. of Thoracic and Cardiovascular Surgery, Korea University,Seoul, 5Korea Artificial Organ Center, Seoul, KoreaBackground: We have developed many mechanical circulatory supportsystems for last twenty years. Various models of VAD, artificial heart andartificial valve were developed, and were applied to animal tests and clini-cal trials. Recently a fully implantable pulsatile BiVAD,AnyHeart, has beendeveloped and applied in a patient for 12 days. AnyHeart’s technologies areapplied to the development of a pulsatile flow extracoporeal life supportsystem (T-PLS) and pulsatile hemofiltraion. Methods and Results: T-PLShas simple blood circuit, biocompatible dual blood sacs, four polyurethanevalves, automation control algorithm and alternating mild pushing mecha-nism. T-PLS provides a physiologically suitable pulsatile blood perfusion forpercutaneous heart-lung bypass. T-PLS has a steady drainage and a pulsatileoutflow with dual blood sacs. Pulsatile blood flow by T-PLS showed thebetter peripheral perfusion in kidney and coronary artery over non-pulsatileblood pump systems. T-PLS has been used as a pulsatile extracorporeal life

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support system and cardiopulmonary bypass pump (central and percuta-neous cannulations) in 110 surgical patients (CABG and Valves) and 50emergency patients (cardiogenic shocks, hemoperfusion). In acute cardio-genic shock or arrest cases, T-PLS’s consecutive application are useful forthree-stage treatments from emergency life-saving, to surgery of PTCA orCABG, then, to the long-term recovery support. Also, the pulsatile bloodpump technology is used for research on the renal replacement treatmentand artificial liver support system. Comparative animal tests of pulsatile and non-pulsatile flow showed advantages of pulsatile blood perfusionsystem with higher rate of toxin removals in the hollow-fiber membranesystem. The pulsatile hemofiltration machine for home-renal cares systemwith higher convection effects are developed and evaluated in animal experiments.

O 097 CONSECUTIVE PATHOGENETIC HEPARIN TREATMENTOF PREDIALYSIS NEPHROTIC SYNDROME NS) PATIENTS—THEDYNAMICS OF HYPERLIPOPROTEINEMIAYu B. Kovaliv. Nephrology Clinic, National Medical University, Lviv,UkraineNephrotic dyslipidemia is a risk factor for the development of systemic ath-erosclerosis and glomerulonephritis (GN) progression. We summarize ourown 10-year experience in the treatment of predialyzed pts with NS usingLMWH and conventional heparin (CH) monotherapy (MT) as 10-daycourses: first LMWH (90 aXa IU/kg b.w. s/c twice a day), then CH (2,5–3mg/kg b.w. s/c 4 times a day); the influence of these 2 heparins on variousclinical, coagulologic, biochemical, immunologic and lipidemic parameterswas investigated before and directly after 10 days of MT courses with eitherLMWH, CH-MT (immediately after LMWH-MT: group I) or CH-MT alone(group II). Lipid-lowering influence of LMWH-MT was observed in 50,5%,while such an effect of CH-MT—in 43% and 42,8%, resp. in I-II groups. InNS pts with acute GN the LMWH-MT also decreased the elevated TG(69%), LDL (56,6%) and Chol. (60%) levels more frequently, than CH perse (resp. in 50%, 52% and 43%). The hypocholesterinemic impact ofLMWH-MT we confirmed even in pts with primary high Chol. (up to 2–3fold) content, while the decrease or normalization of TG was stated pre-dominantly (86,6%) in pts with the latter parameter not exceeding 4,2mmol/l. LMWH-MT induced normalization (58,9%) or positive dynamics(41,1%) of hyperlipoproteinemia type (praecipue from IIb) almost twicemore frequently (64,7%) than CH-MT. On the other hand, CH-MT twicemore frequently than LMWH-MT increased the HDL content in I-II groupsof pts (p < 0,02, p < 0,05 resp.) as well as the coefficient of atherogenicity:82,8% of pts constantly showed the normal HDL value. During LMWH-MT the latter parameter continued to fall while during CH-MT, on the contrary, kept increasing (p < 0,05). Predictors of the beneficial effect ofmentioned heparin therapy prove to be individual TG and HDL contents:decrease of the former and elevation of the latter during such a manage-ment. These anticoagulants have also a positive influence on lipid peroxi-dation. LMWH-MT in the proposed 10-day therapy mode will find anindication for the initial treatment option of NS pts, whereas a consecutiveCH-MT diminishes an undesirable effect of LMWH-MT on HDL content.

O 098 INFLUENCE OF PERITONEAL DIALYSIS MODALITY ON THE PREVALENCE OF PERITONITIS AND EXIT SITE INFECTIONSF. Dumler, N. Khazai. William Beaumont Hospital, Royal Oak, MI, USABackground/Aim: the frequency of cycler assisted peritoneal dialysis(CCPD) is increasing because of greater patient preference and its capa-bility for prescription optimization. Of note, previous observations suggestthat peritoneal dialysis modality influences the prevalence of peritonitis andexit site infections, with patients on cyclers (CCPD) being at greater/lesserrisk than those using manual techniques (CAPD). The aim of this study wasto better define the influence of modality (CCPD and CAPD) on risk ofdeveloping exit site (ES) or peritoneal (PF) infection. Methods: a 96 monthprospective infection surveillance of all peritoneal dialysis patients (N =212) treated at a single center. Results: a total of 40 patients (10 CADP and30 CCPD) developed positive peritoneal (PF) or exit site (ES) cultures.

Conclusions: Our results indicate that: 1) CCPD is associated with a higherprevalence of infectious complications than CAPD; 2) the distribution oftypes of infections is similar in both modalities; 3) Enterococcus and gramnegative infections are less common in CCPD than CAPD.

Cardiac Assist

O 099 CHRONIC HEART FAILURE INDUCED BY MULTIPLESEQUENTIAL CORONARY MICROEMBOLIZATIONS IN SHEEPJ.D. Schmitto, H. Dorge, R. Wachter, P. Ortmann, C. Siebert, C. Ballat,R. Waldmann-Beushausen, H. Post, B. Pieske, F.A. Schondube. Departmentof Thoracic, Cardiac and Vascular Surgery, Georg August University Gottingen, GermanyAlthough a large variety of animal models for acute ischemia and acuteheart failure exist, valuable models of chronic heart failure are scarce. Wetested wether ischemic cardiomyopathy and systolic heart failure can bereproduced experimentally by coronary microembolization in sheep. Sheep(n = 5, 85 ± 6 kg) were anaesthetized, and a 5 F sheath was implanted intothe left carotid artery. The left main coronary artery was catheterized underflouroscopic guidance, and a bolus injection of polysterol microspheres (90 mm, n = 12.500) was performed. Microembolization (ME) was repeatedup to three times in two week intervals until the animals started to developstable clinical signs of heart failure. Clinical and echocardiographic datawere analyzed at baseline (base) and at 3 months (3 mo) after the first ME.All animals developed heart failure, as indicated by increased heart rate(HR) and respiratory rate (RR) at rest and pronounced ascites (Figure 1).LV end-diastolic diameter (LVedD) increased significantly, while EF did notchange (Figure 2). Histologic analysis demonstrated patchy fibrosisthroughout the anterior septum and the free LV wall. We conclude that lossof contractile myocardium after coronary ME can induce LV dilation andneurohumeral activation without a change in LV EF. EF is an insensitiveparameter of this special phenotype of LV damage and dysfunction. Thepresent model may prove suitable in experimental work on heart failureand left ventricular assist devices.

O 100 RECOVERY-DIRECTED LEFT VENTRICULAR ASSISTDEVICE (RDLVAD): INFLUENCE OF ITS MAIN COMPONENTS ONLEFT VENTRICULAR UNLOADINGF. Miyawaki, Y. Takano, D. Satoh, S. Takahashi, M. Hamasaki. Tokyo DenkiUniversity, Saitama, JapanBackground/Aim: RDLVAD makes a failing heart eject blood through avalved apical conduit into a low-pressure afterload-controlling chamber(ACC) made of compliant material, and sends blood from the ACC to theaorta with a continuous-flow type pump, thus achieving LV unloading. Evenexcessive suction never draws blood from LV directly because of interposi-tion of the apical valve and collapsible ACC between LV and the pump,thereby ensuring ventricular relaxation and filling. We investigated the influ-ence of the apical valve and ACC on LV unloading. Methods: Three apicalbileaflet valves were made: 9, 13 and 18 mm in internal diameter. Fourrubber balloons of different sizes were used as an ACC. Their compliances(Cp) depended on their volumes because the elastic moduli of the rubberwere almost identical. The effect of each of 12 combinations made between3 valves and 4 ACCs on a failing heart was studied. After Forrester subset

CAPD CCPD

Patients with + cultures: 10 30*

Median episodes/pt: 2.6 5.6*

Positive ES cultures: 50% 54%

per patient months 32 17*

Positive PF Cultures: 50% 46%

per patient months 20 10*

Staph aureus: 24% 41%*

Staph epidermidis: 23% 29%

Enterococcus: 16% 3%*

Gram negative: 18% 13%*

(*P < 0.01).

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IV heart failure was reproduced in a mock circulation, RDLVAD was con-nected to the mock LV with a 23-mm aortic valve and a 28-mm mitral valve.The heart rate was 100 bpm; the systolic phase was one third of the cardiaccycle. Measurements were repeated 5 times in each setting. Results: 1) The9-mm apical valve was too small to achieve LV unloading. 2) The 13-mmvalve was still too small for even the very compliant ACCs to show any sig-nificant LV unloading. 3) In the case of 18-mm valve, whose opening areawas 60% of that of the aortic valve, the ACC Cp became influential in LVwork. Although the ACC with the lowest Cp (0.1–2.9 mL/mm Hg) had noeffect on LV unloading, the second-stiffest ACC (Cp: 0.1–6.2) showed a sig-nificant unloading. The remaining two ACCs yielded excellent reduction inLV pressure work. Because they had a high Cp of 22 mL/mm Hg within arange of 0 to 4 mm Hg, they kept the ACC pressure very low even duringsystole, indicating that they removed the burden of isovolumic contractionfrom LV and only imposed ejection work. Thus, the RDLVAD made thefailing LV produce a flow of 6.2 L/min by a mean systolic LVP as low as 27mmHg. Conclusion: To make the ACC compliance effective in LV unload-ing, the valve with an opening area of 60% or more was needed. The ACChighly compliant within a range of low pressure contributed to furtherreduction in LV pressure work.

O 101 IN VITRO ANTI-THROMBOGENIC SCREENING OF BIO-MATERIALS UNDER PRACTICAL PULSATILE CIRCULATIONK. Iwasaki1,Y. Takeuchi2, M. Eguchi2, K. Ishihara3, M. Umezu2. 1Institute forBiomedical Engineering, Waseda University, Tokyo, 2Major in IntegrativeBioscience and Biomedical Engineering, Graduate School of Waseda Uni-versity, Tokyo, 3Department of Material Sciences, Graduate School of Engi-neering, The University of Tokyo, Tokyo, JapanAim: We have been pursuing to establish reliable in vitro anti-thrombogenictest methodology using an original pulsatile circulation system. In this study,anti-thrombogenic properties of four different materials were compared instatic and pulsatile flow environments. Methods: The pulsatile circulationsystem can produce hemodynamically identical pressure and flow wave-forms. In every pulsatile experiments, two identical circuits were preparedand filled with blood from one pig to form comparative study. Activ-ated clotting time (ACT) was adjusted to 240 sec using heparin, and the pulsatile tests were terminated in one hour circulation. In parallel, anti-thrombogenicity of 2-methacryloyloxyethyl phosphorylcholine (MPC),Miractran (A segmented polyurethane), Biospan, and PVC were comparedby static tests in 10 minutes at the ACT of 300 sec. Results: Anti-thrombogenic properties were examined using SEM, gold-colloid immuno-labeling, ELISA, and Micro BCA techniques. Static test results showed that protein adsorptions such as fibrinogen, Albumin, and IgG were highlysuppressed in MPC and Biospan as compared to Miractran. PVC was worstamong four materials. MPC was most inert in terms of total quantity ofprotein adsorption. The differences in protein adsorption as well as plateletadhesion were distinct in pulsatile tests. MPC and Biospan showed excel-lent anti-thrombogenicity, whereas MPC is much easier to handle. More-over, there seemed to be a slight difference in protein adsorption amountsbetween housing and moving diaphragm of VAD. Conclusion: The dataabove indicated that our original in vitro test method is quite useful andeffective for screening anti-thrombogenicity of biomaterials as well ascardiac devices in practical pulsatile situations.

O 102 VIABLE BIOENGINEERED VASCULAR SMOOTHMUSCLE GRAFTS–A PROMISING TOOL FOR USE IN SURGICALLEFT VENTRICLE RESTORATIONP. Wilczek1,2, A. Baranska1, Z. Religa1, R. Przybylski2, J. Nozynski1,2,M. Zembala2. 1Heart Prosthesis Institute Biotechnology Laboratory,Zabrze, 2Silesian Centre of Heart Disease, Zabrze, PolandBackground/Aim: Left ventricle surgical restoration is a promising therapyin patients with ischemically altered akinetic or dyskinetic ventricle. Resec-tion of aneurysm simultaneously with the use of an endoventricular patchmay improve the cardiac function because of the chamber size, strain andshape restoration. But the use of a nonviable synthetic patch can limit thistherapy. The aim of the study was to construct a viable patch based on anacellular scaffold seeded with autologous vascular smooth muscle cells.Method: Autologous muscle cells were isolated from human vein. The mor-phology of the cells was confirmed microscopically. The acellular scaffoldwas prepared from pericardium tissue by Typsin/EDTA combined with SDSincubation. Smooth muscle cells were then harvested from the culturedishes, seeded on the acellular scaffold and cultured for 1 week. The effi-

ciency of cells upgrowth on the scaffold was confirmed microscopically.Anaxial tensile test was used to test the biomechanical properties of thenative and treated tissue. Results: The isolated cells had a smooth musclecell morphology. After 1 week’s culture, smooth muscle cells seeded on theacellular scaffold formed a regular, confluent monolayer. Unaxial tensiletest demonstrated similar biomechanical properties of the native andtreated tissue. Conclusion: The preliminary results demonstrate that an acel-lular scaffold can be effectively seeded with smooth muscle cells and can bea promising source for viable endoventricular patch preparation. Viable bio-engineered smooth muscle grafts do not allow restoring the chamber shapeand size, but may actively stimulate the cardiac function improvementprocess.

O 103 CHANGES IN THE EXTRACELLULAR MATRIX OF CAR-DIOMYOCYTES BY ELECTRICAL MICROCURRENT APPLICA-TION. A POSSIBLE NOVEL APPROACH FOR THE TREATMENTOF HEART FAILUREJ. Mueller1, B. Kapeller2, K. Macfelda2. 1Berlin Heart, Berlin, Germany;2Medical University Vienna, Vienna, AustriaObjective: The application of cardiac assist devices has revealed that in asubset of patients even end-stage heart failure can be reversed to normal or nearly normal cardiac function. Generally, by mechanical unloading,improvement of myocyte function was observed to be more pronouncedthan of the extracellular matrix. The composition of different types of col-lagens in the extracellular matrix seems to play a decisive role for the func-tion of the entire myocardium. Investigations on the myocardial levelrevealed that the normalization of the extracellular matrix function wasfound most important and preconditions for a successful reverse remodel-ing process. As known from dermatology and orthopaedics, electricalmicrocurrent application can modulate the collagen composition (collagenI and III) of the extracellular matrix. As a first step of a three step project(cell culture, pre-clinical trial, clinical trial) we investigated the effect of elec-trical microcurrent on cardiomyocytes and the extracellular matrix undercell culture conditions. Methods: The influence of low (50 mA) and high (100 mA) microcurrent on cultured cardiomyocytes from adult rats was com-pared to cultured cardiomyocytes without application of microcurrent(control). Changes in the cell proliferation; collagen I, III; in MMP 2, 3, 8,9, 13, 14, 16; TIMP 1, 2; IL-1b, 6; TNF-a; TGF-b; GM-CSF; connexin 40, 43,45 were measured. Results: After 90 h of cultivation, compared to thecontrol cultured cardiomyocytes proliferation increased by 70% under lowmicrocurrent application. Collagen I synthesis decreased by 35% (lowmicrocurrent) and collagen III increased by 100% (high microcurrent). TheMMPs (3, 8, 9, and 16) expression showed a significant decrease at highmicrocurrent application. The TIMPs remained unaffected. IL-6 was suppressed by high microcurrent. TNF-a, IL-1b and GM-CSF were notdetected at all. High microcurrent leads to a reduced IL-6 and TGF-bexpression. As sign for the viability and functionality of the myocytes theconnexin 40, 43, and 45 showed the most pronounced increase when stim-ulated by low microcurrent. Conclusion: Microcurrent application on cardiomyocytes can influence the components and dependent cellularprocesses of the extracellular matrix significantly by its amplitude.Microcurrent does not induce an inflammatory process, however, accountsfor a reduction of pro-inflammatory cytokines. So it may be conceivable toinfluence the affected extracellular matrix by electrical microcurrent to nor-malize their function in patients with heart failure which remains to be ver-ified in pre-clinical and clinical trials.

O 104 A NOVEL TECHNIQUE USING ECHOCARDIOGRAPHY TO EVALUATE VENOUS CANNULA PERFORMANCE IN CPBCARDIAC SURGERYD. Jegger, P.-G. Chassot1, M.-A. Bernath1, J. Horisberger, M. Jachertz,I. Seigneul, M. Nordien, P.-G. Tozzi, D. Delay, L.K. von Segesser. Depart-ment of Cardiovascular Surgery, 1Department of Anesthesiology, UniversityHospital of Lausanne, SwitzerlandObjective: Echocardiography has never been used to evaluate venouscannula performance. Also, little progress has been made in venous cannuladesign. Therefore, we designed a self expandable Smartcanula (SC) andanalysed its performance capability using echocardiography. Methods:Mean (Vm) and maximum (Vmax) velocities, pressure drop (DPCPB), flowand diameter were obtained from doppler imaging for the control (CC, n =6) and SC (n = 7). LDH and Free Hb were also compared. Comparison wasmade between the two groups using the student’s t-test with statistical sig-

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nificance established when p < 0.05. Results: Age for the SC and CC groupswere 61.6 ± 17.6 years and 64.6 ± 13.1 years respectively. Weight was 70.3 ±11.6 kg and 72.8 ± 14.4 kg respectively. BSA was 1.80 ± 0.2 m2 and 1.82 ±0.2 m2 respectively. CPB times were 114 ± 53 min and 108 ± 44 min respec-tively. Cross clamp time was 59 ± 15 min and 76 ± 29 min respectively (p =NS). Free-Hb was 568 ± 142 U/l vs 549 ± 271 U/l post CPB for the SC andCC respectively (p = NS). LDH was 335 ± 73 mg/l vs 354 ± 116 mg/l for theSC and CC respectively (p = NS). Vm was 89 ± 10 cm/s (SC) vs 63 ± 3 cm/s(CC),Vmax was 139 ± 23 cm/s (SC) vs 93 ± 11 cm/s (CC) (all p < 0.01). DPCPB

was 30 ± 10 mm Hg (SC) vs 43 ± 13 mm Hg (CC) (p < 0.05). Conclusions:The Smartcanula provides superior flow characteristics compared to the CC.No detrimental effects were observed concerning blood damage. Echocar-diography was effective in analysing venous cannula performance.

O 105 FIRST EXPERIENCE WITH A NEW MYOSTIMULATORFOR MUSCULAR CARDIAC ASSISTP. Klapproth1, M. Großherr2, B. Keding1, C. Hansen1, D. Thalmann1,H.H. Sievers1, N.W. Guldner1. 1Clinic of Cardiac Surgery, 2Clinic of Anaes-thesiology, University of Lübeck, GermanyBackground/Aim: The efficacy of muscular cardiac assist depends stronglyon the contractility of the muscle. Up to now, caused by frequent muscleuse, a transformation of an initially mixed type-II/type-I-fiber muscle resultsa in weak and slow 100% type-I fiber muscle. A new myostimulator, whichavoids muscle’s overusage is to test in a chronic animal model evaluating,if the mixed fiber type composition got maintained after a period of 6 monthof electrical stimulation. Methods: Myostimulator’s controller software isoptimized to avoid muscle overusage by considering former stimuli. Animalexperiments were carried out in n = 5 African Bour goats implanting anintrathoracic training device called “frog”, as control serves n = 6 goats with“classical”, uncontrolled stimulation pattern. Muscle’s mechanical perfor-mance was measured once a week; muscle’s fiber characterisation was doneby analysing the myosin heavy chains. Results: Initial myosin heavy chainfiber composition in both groups was type-II: 67% ± 18.8% vs. type-I:31.3% ± 6.2%. After 6 month of stimulation, 100% type-I fibers werearchived in the control group accompanied with weak and slow muscle contractions. End stage stroke volumina SV was less than 10–15 ml. The newmyostimulator stimulated group demonstrates mixed fiber composition withtype-II to type-I fibers of 37.4% ± 17.4% resp. 58,5% ± 18,0% with fasterand stronger contraction and end stage stroke volumina of up to 50 ml.Conclusion: By means of the new myostimulator with its reduced muscleusage, a mixed fiber composition was achieved. In consequence only an on-demand muscular cardiac assist device seems practicable.

Nanotechnology

O 106 NANOSTRUCTURED BIOMATERIALS WITH ELECTRO-SPINNINGC. Reindl1, M. Stoiber1, H. Schmallegger3, L. Huber3, A. Nigisch3,H. Bergmeister4, G. Weigel3, H. Schima1,2. 1Center for Biomed. Eng. andPhysics, 2LBI for Cardiosurgical Research, 3Department of CardiothoracicSurgery, 4Core Unit for Biomed. Research, Med. Univ. Vienna, AustriaAim: The design of artificial scaffolds that mimic the structure of the extracellular matrix is a promising way to enhance biocompatibility. Electro-spinning is a process to fabricate fibres in the nanometer range out of syn-thetic and natural polymers. In this technique fibres are formed bysubjecting a polymer solution to a high electrical field. The aim of this workwas to determine the spinning parameters for different fibre materials andto generate defined orientated fibers. Methods: Electrospinning was donewith an electrostatic field of 10–30 kV at 15 cm gap between the syringe andthe target. The fibres were collected on a specially designed aluminium spec-imen holder, which could be rotated at varying speeds. Additional elec-trodes could be activated to modulate the electric field. Polyurethane,Collagen, Elastin and Fibrinogen were used in a pilot study. Scanning elec-tron microscopy was used to examine the orientation of the fibers. Results:Depending on the rotational speed of the specimen holder, the orientationof the fibres could be varied. A parallel aligned orientation of poly-etherurethane fibres was achieved at a circumferential speed of 20 m/s. Firstresults showed no considerable influence of the electric modulation.Polyurethane, collagen I and III, and fibrinogen exhibited better spinningproperties than Elastin. Conclusion: Electrospinning is a useful techniqueto produce nano-structured surfaces. Modifications in the process allow tovary the orientation and consistence of the fibers.

O 107 DEVELOPMENT OF pH-RESPONSIVE POLYMERIC CAR-RIERS FOR SITE-SELECTIVE DELIVERY OF THERAPEUTICSV. Bulmus1, Y. Chan1, T. Davis1, L. Barner1, P. Stayton2, A.S. Hoffman2.1Centre for Advanced Macromolecular Design (CAMD), The University ofNew South Wales, Sydney, Australia, 2Department of Bioengineering, Uni-versity of Washington, Seattle, WA, USABackground/Aim: Recent studies addressing the site-selective delivery chal-lenge of drugs have utilised environmental-stimuli to release the drugsselectively to a particular body compartment. We have developed two dif-ferent polymeric systems offering acid-triggered release of therapeutics to intracellular targets. Methods: One of the systems is composed of PEGcoated nanoparticles crosslinked with a novel acid-cleavable crosslinker.The second system is composed of a soluble hydrophobic polymer with acid-cleavable side chains of PEG grafts and attached therapeutics. Results: Anovel acid-cleavable crosslinker was synthesised and copolymerized withbutyl acrylate and PEG to form crosslinked nanoparticles. The particleswere stable at neutral pH such as blood pH while they hydrolysed quicklyat slightly lower pHs such as those present at intracellular vesicles andextracellular sites of tumours. Accordingly they exhibited low-pH-depen-dent release of the encapsulated hydrophobic drugs in-vitro. In the secondstudy a soluble polymeric system composed of a hydrophobic backbone wassynthesized. PEG grafts and an antisense oligonucleotide were attached tothe backbone via acid-cleavable bonds. The system was found to be veryefficient to deliver the oligonucleotide drugs to macrophage-like cells. Con-clusion: The results provide preliminary evidence to support the value ofthese novel polymer systems for the intracellular and tumor site-selectivedelivery of various drugs such as small interfering ODNs, peptides and smallmolecular hydrophobic drugs.

O 108 MULTIFUNCTIONAL SURFACES BY COLLAGEN COU-PLING TO NANOTEXTURED TITANIUM IMPLANTSM. Morra, C. Cassinelli, M. Fini1, N. Nicoli Aldini1, G. Giavaresi1,R. Giardino1. Nobil Bio Ricerche srl., Villafranca d’Asti, 1Istituti OrtopediciRizzoli, Experimental Surgery Department, Bologna, ITALYAim: Titanium artificial dental roots and artificial vertebral disks rely oninterfacial osteointegration for efficient function. Surface modificationapproaches to enhance osteointegration are presently based on the controlof surface topography or on ceramic coatings. Surface-linking of biologicalmolecules that can direct events at the tissue/implant interface is a promis-ing new approach to osteointegration. Multifunctional surfaces that coupleadvanced topography modification with biochemical modification can resultin significant improvements of osteointegration rate. The aim of this workis to present surface chemico-physical characterization and results of in vivotesting of titanium implants showing nano-porous surface topography(pores < 1 micron diameter) biochemically modified by the covalent cou-pling of Type I collagen. Methods: Nano-porous surface topography wasobtained by anodization in galvanostatic conditions. Collagen coupling tonanostructured surfaces was obtained by deposition from propene glow-dis-charge plasma, followed by acrylic acid grafting and collagen coupling. Invivo experiments and histological evaluations were performed in rabbit tra-becular bone (4 weeks model), that is still the most challenging type of bonein dental implantology and the more directly relevant in spine artificial disks integration. Results: Surface characterization by scanning electronmicroscopy, atomic force microscopy and x-ray photoelectron spectroscopyconfirm that the treated implant surface shows a hom*ogenous distributionof pores below 1 micron diameter, and a hom*ogeneous, nanometers-thickcoating of collagen molecules. As shown by Atomic Force Microscopy, thesurface layer swells and shrinks as a function of ionic strength, confirmingthat surface-linked molecules maintain conformational freedom. Histo-morphometry evaluation shows that both bone-to-implant contact and boneingrowth at interface are increased on collagen coupled surfaces, with animprovement >60% over the mean value of the uncoated control. Conclu-sion: The described biochemical approach to surface modification of Tiyields a significant improvement of osteointegration rate in trabecular bone,as evaluated by histomorphometry.

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O 109 BIOMATERIAL SURFACE MODIFICATION BY THE THINTiN LAYER DEPOSITIONR. Kustosz1, R. Major2, B. Major2, W. Waldhauser3, J.M. Lackner3, E.Czarnowska4. 1Foundation of Cardiac Surgery Development, Zabrze,Poland, 2Polish Academy of Sciences, Institute of Metallurgy and MaterialsSciences, Cracow, Poland, 3Joanneum Research ForschungsgesellschaftGmbH, Laser Center Leoben, Austria, 4The Children Memorial HealthInstitute, Department of Pathology, Warsaw, PolandAim: Polyurethane is in clinical use as a blood contacting material. Gener-ally, polymeric biomaterials degrade, because body constituents attack thebiomaterials directly or through other device components, sometimes withthe intervention of external factors. Thus it was the reason to modify thesurface to separate PU from body fluids. Methods: Titanium nitride thinlayers were fabricated by pulsed laser deposition with the Nd:YAG laser on biologically applied polyurethane. Transmission electron microscopy(TEM) studies considered layers 250 nm and 50 nm thickness. Finiteelement modeling was performed to establish the temperature distributionin the substrate and in the layer as well as a model of the crack formation.Biocompatibility examinations focused on the material contact with thehuman fibroblast. The fibroblasts were obtained from healthy donors. Cellsfrom the 2–3 passage of the initial culture were moved to the surface of theinvestigated materials in the amount of 1.5 ¥ 105 cells/ml. Results: TEMexaminations revealed columnar structure for the 250 nm thick layers. Suchlayers were observed to be brittle. The model of crack formation consideredslight temperature differences between the layer and the substrate andthermal expansion. In order to improve the coatings elasticity, the layerthickness was reduced to 50 nm, which limited the deposition mechanism tothe early stage. TEM cross-section observation revealed elastic propertiesof the thin layers. Tribological examination revealed good adherence to thesubstrate and toughness increscent. Biocompatibile investigations revealedhigh percentage of alive cells after 48 hour test. Conclusions: The early studyconfirm successful PU modification with depositing of TiN nano-layer whichhas crystalline structure, is biocompatible, well adhered to the polymer andflexible. The technology has been applied in heart assist pump construction.Acknowledgment: The work was supported by the State Committee for Sci-entific Research of Poland under Project: PBZ-KBN-082/T08/2002/ andPBZ-KBN-100/T08/2003.

O 110 TRANSDERMAL DELIVERY OF INSULIN FROM SYN-THETICAL MATRIX: EXPERIMENTAL INVESTIGATION ANDCLINICAL STUDIESE.G. Kuznetsova, O.M. Kuryleva, L.A. Salomatina, V.I. Sevastianov. TheResearch Center for Biomaterials, Research Institute of Transplantologyand Artificial Organs, Moscow, RussiaAim: A possibility of transdermal insulin administration from transdermaltherapeutic system (TTS) in vitro and in pilot clinical trial has been inves-tigated. Methods: The non-woven material (10 cm2) was filled with the emul-sion, which contains insulin (100 IU) and hydrophilic-lipophilic emulsifier asinsulin enhancer. In vitro studies of diffusion of insulin from TTS throughnon-preserved rabbit skin were carried out in the Franz diffusion cells.Insulin was labelled with fluoresceine isotiocyanate. The amount of pene-trated insulin were registered by spectrophotometer Cecil 5000 (UK) at 495 nm. The trial clinical tests were carried out for patients with non-insulin-dependent and insulin-dependent diabetes mellitus. Blood glucosewas measured with blood glucose meter. Results: The insulin diffusion ratein experiments have reached the value (82 ± 14)·10-3 IU·cm-2·h-1. Theoreti-cally, using transdermal therapeutic system with 12 cm2 working areaallowed to reach therapeutic effective insulin rate equalled to ~1.0 IU/h.Results of clinical trials for one patient with Type I diabetes are following.Before transdermal insulin application the average glucose level make up:morning -3.4 +/- 1.0 mmol/L, afternoon -7.0 +/- 2.7 mmol/L, evening -12.3 +/- 1.9 mmol/L. The morning dose of carried over insulin was reducedduring application of transdermal insulin patch. Average glucose level makeup in this case: morning -4.5 +/- 1.9 mmol/L, afternoon -6.3 +/- 1.2 mmol/L,evening -9.7 +/- 0.3 mmol/L. The level of glucose was more stable duringtwo days of insulin transdermal application then in comparison with injec-tion. The therapeutic effect of insulin TTS application for patient with TypeII diabetes was similar. The depressed dose of carried over injection insulinwas compensated by applying insulin TTS. Conclusion: The obtained resultsallow to suggest insulin TTS in therapy for patients with insulin-dependentand insulin-non-dependent diabetes mellitus.

O 111 PLATELET ADHESION ON NANOSTRUCTURED SUR-FACES (NSS) FORMED BY ION-PLASMA METHODSE.A. Remeeva1, I.B. Rozanova1, V.M. Elinson2, V.I. Sevastianov1. 1ResearchCentre for Biomaterials, Scientific Research Institute of Transplantologyand Artificial Organs, Moscow, 2“MATI”–Russian State Technological Uni-versity, Moscow, RussiaAim: The main goal of the study was to investigate the quantitative andmorphological characteristics of platelet adhesion on materials with NSS.Methods: NSS on polyethyleneterephtalate (PET) have been formed bytreatment of initial surface by ions of chemically active and noble gases.Modification was carried out using two methods: by deposition of carbonfilms from directed ion-plasma flows and by magnetron precipitation ofhighly dispersed Al layer. The physicochemical properties of NSS have beenanalyzed by means of AFM, SEM, EDXA and contact angle measurements.Platelet adhesion patterns were investigated by SEM after 15 minutes ofincubation with platelet rich plasma. The parameters of platelet adhesionwere studied depending on hydrophilicity degree and surface structuredimensions. Results: Preliminary treatment of PET by ion bombardmentand a–C:H film deposition leads to the increase in the dimensions of char-acteristic relief features. The correlation between platelet adhesion andcontact angle value was not found for all samples. While the total plateletnumber for nanoscaled surfaces (3 ∏ 8 nm diameter of globules) decreasedcompared to untreated PET and the amount of strongly activated cells wasslightly lower. As for the PET samples with the Al(Al2O3) film, more plateletadhered together with a large number of fully spread platelets was observed.At the same time the SEM study of these surfaces showed the presence ofmicro globules (0.4 ∏ 0.7 mkm diameter). It is likely that the presence ofsuch type of structure provokes the platelet attachment. Conclusion: Thenumber and morphology of platelet adhered depend on the dimensions ofsurface structure rather than hydrophilicity of modified PET. The ion bom-bardment decrease the number of platelet adhered whereas the Al(Al2O3)film deposition provokes their attachment and spreading.

O 112 PRELIMINARY STUDY OF DIALYSATE REGENERATIONTHROUGH POLYURETHANE NANOFIBROUS MEMBRANE IN-VITRO TESTJ.H. Kim1,4,5, H.G. Yoon1,4,5, K.S. Lee1,4,5, B.G. Min2,3,4,5. 1InterdisciplinaryProgram in Biomedical Engineering Major, Seoul National University,Seoul, 2Department of Biomedical Engineering, College of Medicine, SeoulNational University, Seoul, 3Institute of Medical Engineering, MedicalResearch Center, Seoul National University, Seoul, 4Korea Artificial OrganCenter, Seoul, 5Cancer Research Center, Seoul National University Hospi-tal, KoreaAim: The conventional hemodialysis uses a single pass flow of dialysaterequiring large volume of purified water about 140 L. Thus, we would utilizethe regeneration and recirculation of a small volume of dialysate by intro-ducing electrospun polyurethane nanofibrous membrane that removes urea.Methods: The 5 L (250 mg/dL urea concentration) of simulated dialysatewas recirculated for 1 hour and dialysate samples to measure urea removalwere obtained in the dialysate reservoir every 10 min. To remove urea indialysate, nanofiber hemofilter including 8 wt% of electrospun polyurethanenanofibrous membrane was used. Results: When dialysate flow rate wasmaintained about 500 ml/min, approximately 10% of urea in simulateddialysate flow was removed. Conclusion: From this study, we are positive asto the regeneration of dialysate through nanofibrous membrane. In futurestudy, it will be essential that we utilize more suitable polyurethane nanofi-brous membrane to increase urea filtration efficiency.

Extracorporeal Circulation Modeling

O 113 ON-LINE EVALUATION OF VASCULAR ACCESS FLOW INHEMODIALYSIS PATIENTSA. Ciandrini1, C.A. Lodi2, R. Galato3, M.C. Miscia3, S. Cavalcanti1. 1Dept. ofElectronics, Computer Science and Systems, University of Bologna, 2R&DMonitor Division, Gambro Dasco S.p.A., Medolla, 3Nephrology Division,San Carlo Clinic, Paderno Dugnano, ItalyBackground/Aim: The on-line monitoring of vascular access flow (Qa)during hemodialysis treatment is considered useful to allow the early detec-tion of stenosis evolving. We suggest a new method to predict Qa usinginformation usually available during the treatment. In particular, we usedthe difference of pressures between arterial (Paf ) and venous (Pvf ) accesspoints, evaluated at different blood pump flows. Hereafter an in-vivo vali-

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dation test is presented. Methods: Fourteen patients with native artero-venous fistula treated with Integra dialysis machine (Gambro Dasco,Medolla, Italy) were enrolled from S. Carlo Clinic (Paderno Dugnano,Italy). During each session, the blood pressures at arterial and venous dripchambers and the effective blood pump flow (Qbreal) by means of TransonicHemodialysis Monitor were acquired at different values of blood flowsetting (Qbset). Paf and Pvf were then evaluated through a mathematicalmodel of extra-corporeal circuit. Access flow (QaTrans) was measured withTransonic according to the Krivitski method. Finally, the fistula pressure gra-dient (Pf = Paf - Pvf ) was calculated for the different Qbset values andanalysed as a function of the correspondent values of Qbreal. Results: Theexperimental trend of Pf was positive for low Qbset values but it becamenegative for high Qbset values. We defined the value of Qbreal at which Pfbecomes negative as Qbinv. We supposed that Qbinv is related to the fistulahemodynamics in such a way that it can provide information on Qa. Themean QaTrans measured and the mean Qbinv computed were 778 ± 441 ml/minand 208 ± 88 ml/min, respectively (N = 18). The linear regression betweenQaTrans and Qbinv (QaTrans = 0.152*Qbinv + 90.39) presented a good correla-tion (r2 = 0.67, p < 0.001). Then, the access flow evaluated with regressionline was 826 ± 336 ml/min, with a mean prediction error of 6 ± 34%. Con-clusion(s): The on-line method of Qa estimation highlighted a good corre-lation between the access flow estimated and the one measured withKrivitski method. The originality of our method consists in the use of pres-sure values usually available from dialysis machine without the necessity ofsupplementary device.

O 114 COMPUTER SIMULATION OF PLATELET DEPOSITION INEXPERIMENTAL BLOOD FLOW BETWEEN PARALLEL PLATESN. Filipovic1,2, M. Kojic1,2, A. Tsuda2. 1University of Kragujevac, Kragujevac,Serbia and Montenegro, 2Harvard University, Boston, USABackground: Thrombosis and thromboembolism are important from anengineering perspective because they are significant sources of morbidityand mortality in cardiovascular device patients. Design of implants requiresmodeling and simulation of an artificial material and blood flow. The con-tinuum-based method suffers from a major drawback in that the model doesnot describe the behavior of individual blood constituents (e.g., platelets,RBCs, white blood cells). To overcome limitations of the continuum-basedmethods, we use a more fundamental “Lagrangian” discrete particle dynam-ics (DPD) approach that has recently been developed, as a superior.Methods: This method treats colloidal fluid components (e.g., plasma andblood cells in our case) as discrete mesoscopic (micron size) elements thatmove according to Newton’s law. The size of each Voronoi element is smallenough to allow tracking of each constituent of the colloidal fluid, but sig-nificantly larger than the size of atoms so that, in contrast to the moleculardynamics (MD) approach, detailed atomic level analysis is not required.Central to the DPD method is the use of Voronoi space tessellation suchthat mesoscale elements can be considered as clusters of atoms. Results: Totest applicability of DPD method in modeling platelet accumulation weselected simple blood flow conditions for which experimental data are avail-able. Hubbell and McIntire (1986) measured platelet accumulation on a col-lagen wall after 120 s from heparinized whole human blood, flowing betweenparallel plates under steady conditions, with an entrance point platelet con-centration of 2.0 ¥ 10 ml. Our results for platelet accumulation closely matchthe results experimentally recorded by Hubbell and McIntire. These resultsare also in agreement with the numerical continuum-based solution of thediffusion-controlled transport of platelets over a very reactive surface. Con-clusions: The results of the new numerical DPD method show that the maincharacteristics of platelet accumulation on a collagen wall can be repro-duced with the proposed simulation. For development of artificial organslike valves and vessels this method can be applied to critical regions whereit is likely that deposition of platelet will occur.

O 115 ALGORITHM OF CONTROL OF MEMBRANE BLOODPUMP FOR AUTOMATIC MODEN. Kulikov1, D. Sukhov1, O. Khrupachev1, V. Tolpekin2, E. Gasanov2.1Moscow Aviation institute, Moscow, 2Scientific-research institute oftrasplantology and artificial organs, Moscow, RussiaBackground/Aim: Realization of the control of the implantable artificial leftheart-ventricle drive in all modes of its functioning. Methods: VAD is amembrane blood pump, having brushless DC motor drive with roller screwmotion converter. On the converter’s rod there is a pusher effecting thepump’s membrane. For the drive’s control an algorithm based on Frank-

Starling law is used. This allows to archive maximum filling of the pumpwith blood and it’s evacuation controlled by position of the drive’s pusherand blood pump membrane. Position of the pusher and the membrane insystole phase is uniquely defined by the signals from electromotor rotor’sposition sensor. In diastole phase the extent and the rate of the pump fillingwith blood is fixed by optical or magnetic position sensor of the pump’smembrane. Results: Pre-production VAD models were produced. Completetechnical tests on the hydrodynamic test bench were performed. A set ofmedical-biological tests on animals has been done with successful result.Conclusion: The usage of the algorithm provides VAD functioning in semi-automatic, automatic and in possible abnormal modes with optimal hom*o-dynamic and minimum energy spending for keeping acceptable thermalbalance of the implanted system.

O 116 COMPARTMENTAL DESCRIPTION OF FLUIDS ANDSOLUTES TRANSPORT DURING PERITONEAL DIALYSISM. Galach1, A. Werynski1, B. Lindholm2. 1Institute of Biocybernetics andBiomedical Engineering, PAS, Warsaw, Poland, 2Divisions of Baxter Novumand Renal Medicine, Department of Clinical Science, Karolinska Institutet,Stockholm, SwedenBackground: Solute and fluid transport during peritoneal dialysis can besimulated using various models which were developed in the past (i.e. three-pore model or membrane model). These models were very helpful in under-standing the principles of peritoneal dialysis however they do not includeprocesses in the peritoneal interstitium. Methods: The theoretical modelwhere interstitium was included as a separate compartment was proposed.Description of the transport between dialysate, interstitium and blood wasbased on three-pore model extended by the description of fluid uptake byabsorption due to the Starling forces in addition to the absorption by lym-phatics. The mathematical model describing transport of fluids and solutesduring peritoneal dialysis was implemented using program Matlab. Themodel was verified using data from 20 single six hour dwell studies usingstandard glucose 3,86% dialysis fluid in patients on continuous ambulatoryperitoneal dialysis performed in Divisions of Baxter Novum and RenalMedicine, Department of Clinical Sciences, Karolinska Institutet, Stock-holm, Sweden. Results: There was a good agreement between simulationsof the model and experimental data. Also, the estimated parameters of thefluid and solute transport coincided with the parameter values taken fromliterature. With the help of the presented model it is possible to simulatethe behavior of the macromolecular volume marker during passage fromperitoneum to blood as well as change of the values of fluid or solute absorp-tion rates from peritoneal cavity in time. Conclusions: The developed modelseems to provide efficient description of the fluid and solute transportduring peritoneal dialysis as well as fluid and solute absorption from peri-toneal cavity. The model explains not only the discrepancy between fluiduptake and lymphatic absorption, but also between disappearance of themarker from dialysate and its appearance in blood. However, this modelstill requires verification and confirmation as far as the experimental dataof solute concentration in the interstitium during treatment are concerned.

O 117 A NEW MATHEMATICAL MODEL FOR PROFILED-HFRL. Colì, M. Ursino, O. Baraldi, G. Cianciolo, M.L. Soverini, G. Donati,D. Mezzopane, A. Chiarini, C. Raimondi, S. Stefoni. Nephrology, Dialysisand Renal Transplantation Unit, S. Orsola University Hospital Bologna.Department of Electronics, Computer Science and Systems, University ofBolognaBackground: HFR is a dialysis technique effective in patients with MIA 2M related complications. Profiled Dialysis is a dialysis-Syndrome and tech-nique for the treatment of intradialytic hypotension and disequilibrium syn-drome, based on the use of dialysate sodium and ultrafiltration profilesautomatically elaborated “a priori” by a mathematical model of solutes andfluids intradialytic kinetics. Profiled-HFR is a HFR in which dialysatesodium and ultrafiltration are modulated according to profiles elaboratedby the same mathematical model of Profiled Dialysis. Aim of this work isto present the mathematical model and validate its predictive capacityduring Profiled-HFR. Methods: The mathematical model was first derivedand then applied to determine “a priori” individual dialysate sodium andultrafiltration profiles. Data predicted by the model (intradialytic urea,sodium, potassium, osmolarity) were compared with those obtained “invivo”, analysing the correspondence of values in all considered time inter-vals. Measurements have been performed on 10 sessions of Profiled-HFRin 10 patients (one per patient) with mean age 65 ± 15 years, dry body weight

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79 ± 5.3 kg, systolic pressure 101 ± 6 mmHg. During each session studiedevery 30¢ urea, sodium, potassium and osmolarity blood values were mea-sured and compared with those predicted by the model. The correspon-dence between values was statistically evaluated. Results: Analysis of resultsdemonstrated that the model is able to simulate solutes and osmolaritykinetics during the Profiled-HFR sessions. The comparison between themodel prediction and the “in vivo” blood values of urea, sodium, potassiumand osmolarity showed standard deviations lower than those of laboratorymeasurement errors: respectively 1.8, and 0.2 mEq/l for sodium and urea,0.3 g/l for urea and 4.3 mOsm/l for osmolarity. Conclusions: Results suggestthat the model can be used “a priori” to achieve a satisfactory prediction ofsolutes and fluids kinetics and for the automatical elaboration of sodiumand ultrafiltration profiles during Profiled-HFR. The Profiled-HFR allowsto combine the clinical effects of HFR with the stabilizing effect of Profileron intradialytic hypotension.

O 118 COMPARISON OF DIFFERENT METHODS FOR CALCU-LATION OF KT/V AS PARAMETER OF DIALYSIS DOSES. Abbas, S. Stiller, H. Mann. Institute for Applied Nephrology, Aachen,GermanyThere are different methods available for calculation of Kt/V as a parame-ter of dialysis dose which are based on different assumptions, different waysof data acquisition and different methods of calculation. Therefore it isdubious if different methods give comparable results. In this study 4 differ-ent methods for calculation have been compared: On-line clearance mea-surement (Fresenius), Dialog (B. Braun), Efficacy-1.0 (Janssen-Cilag) andformal urea kinetics (Stiller/Mann). Samples for calculation were taken in105 patients at three days of hemodialysis therapy during one week. Addi-tionally consecutive measurements have been done during a longer periodof time. Results:The various methods give results which differ by 25% (Kt/V1,16–1,44) in one treatment. Correlation of the data of different methods isnot always significant. There is also considerable dependence on the daywithin one week and technique how blood samples were taken. Conclusion:Different methods for evaluation of Kt/V give very different results. Inorder to compare dialysis dose in different units only one validated methodof testing Kt/V should be applied.

O 119 UREA KINETIC MODELING OF ADEQUACY INDICESFOR BIMODAL DIALYSISM. Debowska1, J. Waniewski1,2, A. Werynski1, B. Lindholm2. 1Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland, 2Divisions of Baxter Novum and Renal Medicine, Department of Clinical Sciences,Karolinska Institutet, Stockholm, SwedenAim: Bimodal dialysis (BMD), i.e., the combination of peritoneal dialysis(PD) and hemodialysis (HD), offers the advantage of slow continuous ultra-filtration (UF) in PD with superior small solute removal in HD (Kawanishi,2002, McIntyre, 2004). As KT/V for different dialysis modalities can not beadded the aim of this study is the comparison of alternative dialysis ade-quacy indices (fractional solute removal, FSR, defined as total removed ureaamount over maximal urea mass within the body, and equivalent renal clear-ance, EKR) calculated for BMD. Methods: BMD (PD: 4 exchanges ofdialysate every six hours for 5 days per week, HD: 3-hour sessions twice perweek in days without PD) was simulated and compared with the singletherapy, CAPD or HD (3 sessions per week). FSR, EKR, and the profile ofurea concentration in extracellular compartment of patient body were cal-culated. Results: Solute removal (assessed by FSR) was 24% higher in BMDin comparison with CAPD. There was also a substantial difference in EKRwith values of 6.4 ml/min in CAPD and 11.6 ml/min in BMD. CAPD, as asole therapy, was characterized by negligible fluctuations and high level oftime averaged urea concentration (1 mg/ml). At the end of three HD ses-sions urea concentration was four times smaller than the initial value, andtime averaged concentration was 0.65 mg/ml. BMD therapy partially elimi-nated fast changes in solute concentration and allowed to keep time averageconcentration of 0.61 mg/ml. Conclusions: Bimodal dialysis offers the com-bined advantages of both PD and HD modalities. Urea kinetic modelingusing indices FSR and EKR can aid to plan and assess dialysis dose.

Heart

O 120 A NOVEL CONDENSED CARDIOPULMONARY BYPASSCIRCUIT FOR SMALL CHILDRENY. Tsuruhara, Y. Shiokawa, N. Hayashi. Department of Pediatric CardiacSurgery, Kumamoto City Hospital, Kumamoto, JapanBackground/Aim: We have developed a novel condensed pediatric car-diopulmonary bypass (CPB) circuit with a minimized priming volume toreduce hemodilution that can adversely affect fluid balance and organ func-tion. Here we describe our new system in detail and the clinical observa-tions. Methods: The core apparatus of the circuit is the Shieldpack, whichwas newly released by Terumo Corp. and was customized to our current per-fusion system. The feature of the circuit is a clear sterilized hard-shell domethat houses an oxygenator, a venous reservoir, and a heat exchanger inside.The dome is placed directly contacting with the surgical table to minimizethe distance between the heart and the reservoir, whereas perfusionists caneasily handle the apparatus inside the dome. All components including abubble trap and an ultrafiltration circuit are ideally assembled usingminimal-length tubing. The CPB flow was maintained between 2.5 to 3.0 L/min/M2 with gravity drainage under moderate hypothermia. In paral-lel with the introduction of the new circuit, we raised the acceptable lowesthematocrit value during CPB by 3%. We applied this circuit to 62 consec-utive children with congenital heart defects weighing 11 kg or less (groupS), and the clinical observations were compared with those of former 79consecutive children weighing 11 kg or less with conventional CPB circuit(group C). The median age of the patients was 5.4 months (7 days to 4.4years), the median body weight was 5.4 kg (2.5 to 11 kg), and no differenceswere found between the groups. Results: There was no unfavorable com-plication with the new circuit. In the cases with bloodless priming, meanpriming volume were 180 +/- 7.2 ml (166 to 208 ml) in group S (n = 32) and232 +/- 51 ml (200 to 559 ml) in group C (n = 45) (P < 0.0001). Consequently,post CPB/pre CPB hematocrit ratio as an indicator of hemodilution was sig-nificantly preserved in group S (0.65 +/- 0.12) as compared with group C(0.53 +/- 0.09, P < 0.0001). Although the requirement for blood transfusionwas not reduced, mean lowest hematocrit during CPB was higher in groupS (22.0 +/- 4.5) than goup C (16.2 +/- 4.0%, P < 0.0001). Conclusion: Ournew circuit brought about reduced hemodilution during CPB, and conse-quently could contribute to more preserved organ function during and afterCPB in small children.

O 121 AUTOPSY FINDINGS IN PATIENTS AFTER POSTCAR-DIOTOMY EXTRACORPOREAL MEMBRANE OXYGENATIONA.J. Rastan1, N. Lachmann1, N. Doll1,T. Walther1, C. Wittekind2, F.W. Mohr1.1Heart Center, 2Institute of Pathology, University Leipzig, GermanyBackground: To assess causes of death including clinical sensitivity, con-comitant diseases and postoperative complications in ECMO patients.Methods: Between 1/00 and 12/04 1.079/17.403 pts. (6.2%) died after cardiacsurgery. 115 of these pts. had premortem postcardiotomy ECMO circula-tory support. Autopsy was performed in 63 (54.8%) consecutive ECMO pts.Clinical and post-mortem data were prospectively recorded and comparedconcerning causes of death and postoperative complications includingvenous and arterial thromboembolisms and EuroSCORE relevant diseases.Results: Mean survival was 17.8 d. ECMO weaning rate was 59.5%. Causeof death were cardiac in 61.9%, multi-organ failure/sepsis in 9.5%, cerebralin 4.8%, respiratory in 9.5%, fatal pulmonary embolism in 9.5%, technicalin 2.4%, and mediastinitis in 2.4%. Unexpected causes of death were found in 24 patients (38.1%) including myocardial infarction (6), acute heartfailure (8), fatal pulmonary embolism (4), pneumonia (4) and severe cere-bral bleeding (2). Premortem unknown concomitant diseases were found in51 patients (80.9%) with therapeutical relevance in 18 patients (28.6%) andled to EuroSCORE alterations in 50.8%. Preoperative additive (logistic)EuroSCORE significantly changed from 12.1 (34.6%) to 12.7 (39.1%) afterautopsy evaluation (p = 0.02). Clinically unrecognized complications werefound in 61 patients (96.8%). These were acute cerebral ischemia (9), acutepancreatitis (4), gastrointestinal ischemia (5), pneumonia (9) and throm-boembolic events (see table). Conclusions: Autopsy reveal major discrep-ancies between clinical and post-mortem examination in ECMO patients.The true incidence of thromboembolic events is highly underestimated byclinical assessment.

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Clinical AutopsyThromboembolic event findings findings

Overall venous thrombosis 3 (4.8%) 33 (52.4%)Upper extremity thrombosis 0 27 (42.9%)Lower extremity thrombosis 0 9 (14.3%)Caval & right heart thrombus formation 0 9 (14.3%)Overall arterial embolism 3 (4.8%) 15 (23.8%)Upper extremity arterial embolism 0 0Lower extremity arterial embolism 0 6 (9.5%)Left heart thrombus formation 3 (4.8%) 12 (19.0%)Fatal pulmonary embolism 4 (6.3%) 6 (9.5%)Non fatal pulmonary embolism 2 (3.2%) 24 (38.1%)Minor cerebral embolism 8 (12.7%) 21 (33.3%)Splenic infarction 0 4 (6.3%)Renal infarction 0 5 (7.9%)

O 122 MORE THAN 2 YEARS ON MECHANICAL CIRCULATORYSUPPORTT. Drews, M. Jurmann, R. zu Dohna, M. Pasic, Y. Weng, R. Hetzer.Deutsches Herzzentrum Berlin, GermanyBackground/Aim: As experience has been gained with mechanical circula-tory support (MCS), the application of long-term MCS has become ofincreasing interest. This study presents the long-term results of 16 patientson mechanical circulatory support (MCS) for more than 2 years. Methods:Sixteen patients who have been supported with an MCS system for morethan 2 years were studied. There was 1 patient on biventricular (BerlinHeart Excor) and 15 patients on left ventricular circulatory support (6Novacor, 4 Berlin Heart Incor, 4 Berlin Heart Excor and 1 Lion Heart).They received assist device implantation between July 1994 and February2003 at a mean age of 49 years (20–72 years). The diagnosis in 10 patientswas dilatative cardiomyopathy (CMP) and in 6 ischemic CMP. Results: Sofar these patients have a mean support time of more than 3 years (1158 days,range 788–1863 days). Sixteen patients have been supported by a device formore than 2 years, 7 for more than 3 years, 5 for more than 4 years and 1for more than 5 years. There were 5 assist-device related complications with4 cases of pump exchange (3 Novacor, 1 Berlin Heart Incor) and 1implantable controller exchange (Lion Heart). All patients were dischargedduring time on MCS and 15 patients (94%) have been at home for morethan 1 year. In total, 6 patients could be transplanted, 5 patients died, 1 wasweaned and 4 are still on the device. Conclusions: Our experience showsthat long-term MCS can be used with an acceptable quality of life and anacceptable rate of complications. It ensures the survival of these patientsand reintegration into the family.

O 123 INITIAL CLINICAL EXPERIENCE WITH THE CORAIDECARDIAC ASSIST SYSTEMA. El-Banayosy1, L. Arusoglu1, M. Rinaldi2, M. Morshuis1, L. Golding3,D. Cobaugh1, L. Kizner1, R. Koerfer1. 1Heart and Diabetes Center NRW,Bad Oeynhausen, Department of Thoracic and Cardiovascular Surgery,Ruhr-University Bochum, Germany, 2Clinico San Matteo, Universita Pavia,Italy, 3Cleveland Clinic Foundation, Cleveland, OH, USABackground/Aim: The increasing demand for long-term mechanical circu-latory support (MCS) has led to the development of long-term implantableblood pumps. One of them is the Arrow CorAide left ventricular assistsystem (LVAS), an electrically powered, magnetically levitated third gener-ation assist device. Here we report the initial experience of the Europeanclinical feasibility trial with this system which was started in 2/2005.Methods: From 2/2005 until 6/2005 6 patients (pts) received the CorAide asbridge to transplantation for low cardiac output. All pts were male. Under-lying cause for the LOS was ICM in 5 pts and DCM in 1 pt. All pts wereprior to implant on at least 2 inotropes, 4 pts have had former cardiacsurgery, 3 had an AICD, 2 were on IABP support. All relevant hemody-namic data as well as pump data and adverse events are collected and ana-lyzed. Results: All pts are presently surviving with a duration of support of5–127 days. The 2 pts longest supported are at home (1 at 127 days postimplant and the other 118 days post implant). All surgical implantationswere easy and uneventful. In the first 24 hours postoperatively 2 pts requiredreoperation, the first for bleeding due to coagulopathy, the other for cannularepositioning. Another pt developed a late tamponade requiring drainage.2 pts suffered from right heart failure necessitating treatment with Ilome-dine inhaler. No pt developed thrombemboli or hemolysis. Pump functionwas without problems. The automatic control mode is in use in 5 pts. The

average flow ranges from 4.1 L/min–5.8 L/min, with a mean flow of 5.0 ±0.7 L/min. With exercise flows increase up to 8.0 L/min. Average motorpower is 4.4 ± 0.4 Watts. Conclusions: Our initial experience shows that theCorAide is a reliable and safe device which so far has shown excellent pumpfunction and has reduced problems, which are commonly associated withMCS, like hemolyses, infections or thrombemboli.

O 124 MECHANICAL STRESS ACTIVATES PLATELETS AT ASUBHEMOLYSIS LEVELI. Bakir, P. Luyten, H. Bollen, V. Leunens, B. Meyns. Center for Experi-mental Surgery, Leuven, BelgiumBackground: Thrombo-embolic complications are common in patientstreated with ventricular assist devices and probably due to chronic bloodtrauma. We sought to identify the relationship between platelet damage andhemolysis as a consequence of mechanical stress by blood pumps. Materialand Methods: Blood of six healthy adult Dorset sheep was drawn and testedin a hemoresistometer device. In each experiment blood, anticoagulated byhirudin, of the same animal was exposed to shear rates of 775 s-1, 1.550 s-1,2.325 s-1, 3.100 s-1, 3.875 s-1 and 4.650 s-1 for a duration of 15 minutes. Shearexposed blood was immediately fixed by paraformaldehyde for preciseplatelet counting. Hemolysis was determined by the level of free hemo-blobin in plasma. Results: In all animals, hemolysis (triangles) increased sig-nificantly from a shear rate of 3.100 s-1. Platelet count (squares) droppedimmediately (contact, low shear), dropped a second time at a shear rate of2.325 s-1 and increased slightly as soon as hemolysis starts. The latter is dueto interference of shared red blood cells. At higher shear rates, hemolysisincreases further and platelets are lost.

O 125 LEFT VENTRICLE LOAD IMPEDANCE CONTROL BYAPICAL VAD CAN HELP HEART RECOVERY AND PATIENT PERFUSIONM. Arabia1, F. Colacino1, F. Moscato1, F. Piedimonte2. 1Mechanical Engi-neering Dept, Univ. of Calabria, Rende, 2Automation Dept, Univ. of Rome,Tor Vergata, Rome, ItalyBackground/Aim: Left ventricle (LV) unload exerted by apical vad resizesheart, shifts pressure-volume (PV) loop toward low volumes, and increasesflow rate. Afterload (A) or, better, load impedance (ZL) control canstrongly improve the Starling function as well as the heart mechanical oper-ation. This study is concerning with the dependence between ZL and theconsequent benefits, and it is based on the LV elastance, E(t), Guyton’s cir-culatory, and pulsatile vad models. Methods: E(t) parameters can be evalu-ated by using a pulsatile vad to properly modify A or ZL and to know flowand pressure in apical cannula; by varying A or ZL the differential valuesof the max activation and passive elastance curves can be estimated. Theidentified E(t) will allow to drive the vad in order to select an appropriatelow end systolic LV volume by properly controlling A or ZL, thus balanc-ing the LV stroke volume which depends on the circulatory system controls.By knowing pressure and flow into the cannula and the E(t), the LV PVloop is known as well. From E(t) and PV loop depend the LV mechanicalefficiency, wall stresses, Starling relation. A possible heart operation modecan be then selected by a proper control of A or ZL, thus satisfying clinicaltargets. Results: Computer experiments allowed to optimize the efficacy ofthis method and confirm its feasibility. Conclusions: Passive diastole inactual pulsatile VAD does not allow A or ZL control. Good results for heartrecovery are achievable, but commercial VADs must be improved, particu-larly in their functional properties.

POSTER PRESENTATIONS

Polymers and Scaffolds

P 001 EVALUATION OF HYDROSTATIC PRESSURE ON CHON-DROCYTES METABOLISM ON A BIODEGRADABLE POLY-URETHANE SCAFFOLDS. Karbasi1,2, H. Mirzadeh*1, F. Orang1, J.P.G. Urban3. 1Amirkabir Univer-sity of Technology, Faculty of Biomedical Engineering, Tehran, Iran, 2Bio-medical Engineering Department, School of Medicine, Isfahan Universityof Medical Science, Isfahan, Iran, 3Disc Group, University Laboratory ofPhysiology, Oxford University, Oxford, UKAim: One of the imminent applications of tissue engineering is the repairand replacement of osteoarthritic or damaged articular cartilage. In thismethod, the tissue is repairing by chondrocytes [1] or stem cells [2] with

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matrix synthesis on a biodegradable scaffold. Methods: Hydrostatic pres-sure is one of the key factors that control chondrocytes metabolism. In thisresearch, the effect of hydrostatic pressure was investigated on lactate production and GAG (glycosaminoglycane) content in chondrocytes. Thechondrocytes were seeded on Degrapol® scaffold, as a biodegradable polyesterurethane scaffold (DBS), and 4 MPa was applied to the samplesfor 4 h per day as a cyclic (1 HZ, Sinusoidal) load. Results: Our resultsshowed that hydrostatic pressure could increase the amount of GAG, lactateand rate of lactate production as a significant cartilage metabolism on DBS.Conclusion: the presence of hydrostatic pressure for in vitro experiments isa good stimulation for chondrocyte metabolism; because normally the artic-ular cartilage is under hydrostatic pressure. It seems likely that this type ofscaffold (DBS) has good potential for tissue engineering of articular carti-lage under different physical conditions.

P 002 DIFFUSIVELY TRANSPARENT ALBUMIN COATING OFMASS-FRACTAL CARBONIC HEMOSORBENTSV.V. Sarnatskaya1, V.G. Nikolaev1, S.V. Mikhalovsky2. 1Institute of Experi-mental Pathology, Oncology and Radiobiology NAS, Kiev, Ukraine,2Brighton University, Brighton, UKGood hemocompatibility is an important requirement for modern carbonichemosorbents and is achieved by the coating of carbonic surface with dif-ferent polymers particularly with human serum albumin. However, albumin,as well as other coatings, decreases the capacity of carbonic matrix towarda number of toxic compounds and metabolites, specially of hydrophobicnature. In the report, the data concerning diffusively-transparent coating formass-fractal HSGD hemosorbents on the base of pH- and ligand-inducedHSA conformers are presented. It is shown that by optimization of tertiarystructure of albumin one may achieve practically total diffusive trans-parency in despite of massive (up to 950 mg/g) albumin coating of highlyporous carbonic matrices and high adsorptive activity toward such albumin-bound ligands, as nonconjugated bilirubin, bile acids, phenols, 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF). That way allows to obtaincombined protein-carbonic hemosorbents completely preserving uniqueabsorptive properties of mass-fractal matrices, that bind tens-fold higherhydrophobic poisons, than conventional activated carbons usually used forpurification of blood plasma and total blood.

P 003 TITANIUM PHOSPHATES FOR OSTEOINTEGRATIONE.A. Krylova1, A.A. Ivanov1, S.E. Krylov1, I.G. Plahchina1. 1N.N. EmanuelInstitute of Biochemical Physics RAS, RussiaThis work presents some results concerning the size-controlled TitaniumPhosphates (TP) microparticles produced by coprecipitation from biopoly-mers (BP) solutions with the use of soluble precursors salts by means of dif-ferent ratio between components. The synthesis and properties of filmscontaining BP and inorganic TP microparticles is studied so as determinethe optimal film matrix for bone tissue recovery. The BP employed includecollagen, chitosan. The reaction was completed at pH of 7.2. After process-ing the samples were dehydrated and studied by X-ray, DTA and IR-analy-sis. The comparison of the infrared spectra showed that films have thestructure with all basical characteristic peaks of the hydroxyapatite and withsome additional peaks concerning to interactions between BP and TP. Ourresearch is focused on studying the structure of this films. In order toobserve such structures, we used both transmission (TEM) and scanning(SEM) electron microscopy. The TP films synthesized using this route wasfound to be micro-sized TP (1–2 mkm).

P 004 DEHP INCREASES FLUIDITY OF MEMBRANE GEL-PHASE MICRODOMAINS AND ENHANCES STORE-OPERATEDCALCIUM ENTRY IN HUMAN GRANULOCYTESS. Palleschi1, B. Rossi1, G. Severini1, L. Diana1, L. Silvestroni2,G. Splendiani3. 1Dept of Hematology, Oncology & Molecular Medicine,Istituto Superiore di Sanità, Rome, 2Dept of Medical Physiopathology,University “La Sapienza”, Rome, 3Dept of Nephrology and Dialysis,University “Tor Vergata”, Rome, ItalyBackground/Aim: Di(2-ethylhexyl)phthalate (DEHP) is a commonly usedplasticizer in PVC medical devices for extracorporeal circulation. SinceDEHP is not covalently bound to the plastic matrix it can easily migrateinto biological fluids. DEHP is known to inhibit major Ca2+-mediated poly-morphonuclear leukocytes (PMNL) functions such as chemotaxis and bac-tericidal activity. Being PMNL Ca2+ signalling apparatus intimatelyassociated with highly-ordered lipid microdomains, and considering the high

lipophylicity of DEHP, we investigated the plasticizer effects on PMNLmembrane fluidity and intracellular free calcium concentration ([Ca2+]i).Methods: Blood samples were collected from healthy volunteers and PMNLwere isolated by centrifugation on Percoll density gradient. The fluorescentprobes Laurdan and Fura-2 were used to assess membrane fluidity and[Ca2+]i, respectively. Results: Laurdan spectroscopy indicated that, in therange 4 ∏ 42°C, gel and liquid-crystalline phase lipid domains coexist in theplasma membrane of PMNL. DEHP dose-dependently increased fluidity ofgel-phase domains up to induce transition into liquid-crystalline phase. Theplasticizer was also able to significantly increase the Ca2+ influx resultingfrom the intracellular Ca2+ store depletion. The latter effect was time- anddose-dependent with maximum reached at 15 min and a DEHP/cells ratio≥ 0.0005%/10Ÿ6 *ml. Neither DAG-activated calcium channels nor PKC-dependent mechanisms were involved in the phenomena observed. Bovineserum albumin addition totally abolished the plasticizer effect on [Ca2+]i.Conclusions: The present findings show that DEHP partitions into PMNLmembrane thereby i) fluidifying the highly-ordered, gel-phase lipid domainsand ii) interfering with store-operated Ca2+ entry. Since fundamental cellsignalling events are localized in highly ordered lipid domains, we suggestthat DEHP intercalation into the cell membrane may play a role in the plasticizer toxicity.

P 005 NOVEL TITANIUM COATING OF ePTFE GRAFTS: FRIENDOR FOE?B.H. Walpoth1, M. Cikirikcioglu1, N. Sedelnikov2, E. Khabiri1, A. Antal1,T. Tatar1, S. Da Cruz1, J.-C. Tille3, O.M. Hess4, A. Kalangos1. 1Department of Cardiovascular Surgery, University Hospital, Geneva, Switzerland,2Institute Ginalmazzoloto, Moscow, Russia, 3Department of Clinical Path-ology, University Hospital, Geneva, 4Swiss Heart Center, Bern, SwitzerlandBackground/Aim: Patency of small synthetic bypass grafts is inferior toautologous grafts. Titanium coating of vascular grafts has been shown todecrease thrombogenicity, enhance biocompatibility and to promote adhe-sion of endothelial cells, resulting in improved patency. The aim of this studywas to test the short term patency and endothelialisation of novel coatingof ePTFE grafts with titanium. Methods: Bilateral carotid graft interposi-tion was performed in 5 pigs (ePTFE, 4 mm ID, 50 mm long). The 10 graftswere either uncoated (n = 5), or titanium coated (n = 5). Each pig served asits own control. Anastomosis quality was assessed by intraoperative flowmeasurement, Doppler ultrasonography and selective angiography at day0,7,30. At the end of the study (30 ± 3 days), grafts were excised for histol-ogy and scanning electron microscopy. Computed morphometry was carriedout to determine intimal hyperplasia and percentage of cellular graft cov-erage. Results: At 1 month, patency rate was 80% for native and titaniumcoated grafts. Quantitative angiography did not show any significant differ-ence between the groups. Morphometry revealed a significantly higher cel-lular coverage (CD 31+ cells) for titanium coated (84 ± 19%) than uncoatedgrafts (48 ± 26%, p < 0.001). There was a trend (Table) towards increasedintimal hyperplasia in titanium coated (254 ± 68 mm2/mm) compared touncoated grafts (172 ± 95 mm2/mm). Conclusions: Patency rates were similarin ePTFE and titanium coated grafts at one month. However, titaniumcoating showed a significant improvement in neo-endothelialization com-pared to uncoated grafts. Thus, titanium coating of ePTFE grafts may be apromising solution to improve results in small synthetic vascular grafts.

Native TitaniumePTFE coated ePTFE P**(n = 4)* (n = 4)*

Whole graft 60 ± 57 94 ± 61 0.112

Anastomoses 172 ± 95 254 ± 68 0.051(proximal+distal)

Middle of 27 ± 23 68 ± 58 0.175the graft

Whole graft 48 ± 26 84 ± 19 0.001

Anastomoses 98 ± 5 100 ± 0 0.705(proximal+distal)

Middle of 39 ± 16 77 ± 25 0.002the graft

Inti

mal

hype

rpla

sia

(mm

2 /(mm

)

Neo

-en

doth

elia

lco

vera

ge (

%)

*Only patent grafts were evaluated, **Mann Whitney U test.

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P 006 IN VITRO BIOACTIVITY OF POLY (epsilon-CAPROLACTONE)-APATITE (PCL-AP) SCAFFOLDS FOR BONETISSUE ENGINEERING: THE INFLUENCE OF THE PCL/AP RATIOP. Taddei, M. Di Foggia, C. fa*gnano. Dipartimento di Biochimica “G. Moruzzi”, Sez. di Chimica e Propedeutica Biochimica, Università diBologna, Bologna, ItalyBackground/Aim: Porous POLY (epsilon-CAPROLACTONE) (PCL) isused as long-term bioresorbable scaffold for bone tissue engineering. Thebone regeneration process can be enhanced by addition of apatites (AP).This study was aimed at evaluating the influence of the PCL/AP ratio onthe in vitro degradation and bioactivity of composites. Methods: Thesamples (synthesised at the Istituto per la Tecnologia dei Materiali Com-positi-CNR, Napoli) had the following PCL/AP wt/wt ratios: 50/50, 60.5/39.5and 74.5/25.5. The in vitro biodegradation was investigated under sterileconditions at 37°C in different media: saline phosphate buffer at pH 7.5(SPB), 0.01 M NaOH solution, simulated body fluid at pH 7.5 (SBF) andesterase in SPB. The samples were analysed by Raman spectroscopy, ther-mogravimetry (TG) and differential scanning calorimetry (DSC). Results:Raman and DSC analyses of the undegraded samples showed that the crys-tallinity degree of the PCL component was decreasing along the series:50/50 > 60.5/39.5 > 74.5/25.5. After 28 days of treatment, the samples showed different degradation patterns and extents depending on the degra-dation medium, the starting PCL crystallinity and composite composition.Weight measurements, Raman and TG analyses revealed deposition of anapatitic phase on all the composites immersed in SBF. Conclusions: All thesamples displayed a good bioactivity; the sample which showed the mostpronounced apatitic deposition was 50/50, i.e. that containing the highestamount of AP.

P 007 INDUCTION OF GRANULATION TISSUE INSIDE LACTICACID-CAPROLACTONE COPOLYMER CUBES IN THE THORACICCAVITY OF RABBITS AFTER PNEUMONECTOMYS. Chang1, Y. Yamamoto1, H. Igai1, N. Misaki1, M. Gotoh1, T. Okamoto2,T. Kushibiki3, Y. Tabata3, H. Yokomise1. 1Second Department of Surgery,Faculty of Medicine, Kagawa University, 2Respiratory Surgery, f*ckui RedCross Hospital, 3Institute for Frontier Medical Sciences, Kyoto University,JapanBackground: Post-pneumonectomy empyema is still a major problem in thefield of general thoracic surgery. All surgical procedures currently employedfor treating chronic empyema are based on two major concepts: clearing ofthe empyema cavity and closing of the resulting dead space. Although manydifferent surgical techniques are available for closing of the dead space,most of them have a detrimental outcome in terms of respiratory functionor cosmetic considerations. In the present study, we investigated whetherlactic acid-caprolactone (LA-C) copolymer cubes could induce granulationin the thoracic cavity of rabbits after pneumonectomy and evaluated theeffect of basic fibroblast growth factor released slowly from gelatin micros-pheres (FGF-GMS). Materials and Methods: Six control rabbits underwentpneumonectomy alone, four underwent pneumonectomy followed by place-ment of LA-C cubes in the post-pneumonectomy cavity, and six underwentpneumonectomy followed by placement of LA-C cubes and sprinkling ofFGF-GMS within the cavity. Results: The control rabbits showed no growthof granulation tissue. On the other hand, a fibrous collagen layer coveredall of the implanted LA-C cubes. Induction of granulation tissue was limitedinside the LA-C cubes, starting from their periphery, and continued for 3months in the LA-C group but gradually diminished in the LA-C + FGFgroup. Inflammatory cells invaded the LA-C cubes along the septa that sep-arated the pores. FGF-GMS encouraged the invasion of fibroblasts into thepores and accelerated thickening of the covering fibrous layer. Conclusion:We attempted to induce the regeneration of host tissue in an uninfected tho-racic cavity after pneumonectomy using bioabsorbable materials with orwithout added growth factor. Our final aim is to achieve closure of the post-pneumonectomy empyema cavity by stimulating host tissue regenerationwith LA-C cubes. However, as a first step, we focused on histological eval-uation of granulation tissue, and the effects of different treatments usingLA-C in the thoracic cavity.

P 008 UroMaix COLLAGEN SCAFFOLDS FOR URINARY TRACTRECONSTRUCTIONC. Becker1, I. Heschel2, T. Läufer1, G. Jakse1. 1Department of Urology,University Hospital and Medical Faculty, Aachen, 2Matricel GmbH,Herzogenrath, GermanyBackground: Reconstruction of bladder and ureter tissue is indicated incases of injury, stenosis, infection or tumor. Substitution by ileum, colon orpure synthetic polymers causes a variety of complications. Biohybrid tissueresembling the structural and functional multilayered wall architecture ofthe urinary conduit may help to overcome the current problems. Aim: Wehave designed and validated new collagenous matrices (UroMaix) for invitro-colonisation with primary urinary tract cells. Methods: Medicallyapproved bovine collagen-I was subjected to a new freeze-drying processfor unidirectional solidification. Bladder tissue was prepared from porcineorigin. Cells were isolated by microdissection and enzymatic digestion fol-lowed by incubation in selective growth media. Urothelial and smoothmuscle cells were seeded in a density of 5*10Ÿ5 cells/cmŸ3 scaffold and biohybrids were incubated in a batch culture system for up to 14 days.Cellular increase was measured by mitochondrial activity assay and topographical orientation of cells was visualized immunohistochemically.Results: Three double layered matrices (UroMaix) with increasing crosslinkings were produced. Each layer exhibited orientated and hom*ogenouspore structures. Urothelial cells showed maximum attachment on the thinsmooth layer of UroMaix-1 and a significant increase of living cells duringthe first 9 days of culture. Thereafter, cellular amount decreased, due to thedegradation process of the low cross linked matrix. No attachment ofurothelial cells occurred on the other prototypes. Smooth muscle cellsshowed similar behaviour on the bulky cavernous layer of UroMaix-1 butsignificant higher increase of living cells on the higher cross linkedUroMaix-2 and -3. During the incubation period, both urothelial andsmooth muscle cells retained their phenotypes as demonstrated by transla-tional expression of CK-18 and myosin-hc respectively. Conclusion:UroMaix scaffolds support attachment and proliferation of urinary tractcells. A combination of smooth layer of UroMaix-1 and cavernous layer ofUroMaix-2 will optimise cocolonisation. The elastomeric properties of thecollagenous matrices offer attractive applications in tissue engineering ofthe urinary tract regarding its mechanical demands in consequence of flu-iddynamic processes.

P 009 MULTISLICE SPIRAL COMPUTED TOMOGRAPHY (MSCT)FOR CORONARY ARTERY CALCIFICATIONS IN HEMODIALYSISPATIENTSG. Cianciolo, L. Colì, G. Donati, M.L. Soverini, E. Persici, O. Baraldi,R. *Fattori, V. *Russo, E. Tampieri, A. Chiarini, S. Stefoni. Nephrology,Dialysis and Renal Transplantation Unit, *Radiology Unit, S.Orsola University Hospital BolognaBackground: MSCT is a new non invasive tool to measure coronary arterycalcifications and can show a developing cardiovascular disease. The rela-tionship between coronary artery calcifications and cardiovascular riskfactors was evaluated in a group of 36 stable HD patients. Methods: 21males and 15 females, age 60.3 ± 13.8 years, were considered. Age on HDtreatment was 60.8 ± 66.2 months (range 1–245). All the patients underwentto MSCT to evaluate the coronary calcification score according to Agatston.hom*ocysteine, CRP, albumin, lipid profile, PTH, calcium, phosphorus wereevaluated before the midweek HD session. A correlation test was carriedout between cardiovascular risk factors and calcification score. Patientswere grouped by age on HD: 0–12 months (group A = 11 patients), 13–60months (group B = 14 patients) and > 60 months (group C = 11 patients).Results: For all patients considered coronary calcification score mol/l, CRP0.8 ± 0.36 mg/dl, was 1267.3 ± 1790.3 Agatston, hom*ocysteinemia 31.5 ±33.9 albumin 4.0 ± 0.5gr/dl, total cholesterol 164.0 ± 65.4 mg/dl, HDL 46.6 ±14.4 mg/dl, LDL 72.0 ± 33.3 mg/dl, triglycerides 200.0 ± 152.6 mg/dl, PTH372.8 ± 308.9pg/ml, calcium 9.0 ± 0.7 mg/dl, phosphorus 5.3 ± 1.7 mg/dl. Ingroup A (age 61.5 ± 14.1 years) calcification score was 423.6 ± 613.8 Agat-ston. In group B (age 63.7 ± 14.3 years) calcification score was 432.7 ± 536.2Agatston. In group C (age 52.5 ± 9.2 years) calcification score was 3432.2 ±2292.9 Agatston (p = 0.02 vs group A, p = 0.02 vs group B). As regards hom*o-cysteine, CRP, albumin, lipid profile, PTH, calcium and phosphorus, no dif-ference was found in the three groups. Correlation between calcificationscore and HD age was r = 0.7, between age on starting HD and 0.6, betweenserum calcium and calcification score r = 0.3, calcification score r = no cor-relations were found between calcification score and PTH, hom*ocysteine,

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LDL, CRP. Conclusions: MSCT coronary angiography permits reliabledetection of calcifications in HD patients. The calcification score was sig-nificantly high in HD patients as compared with the general population, thepatients with higher HD age show higher calcification score. No correlationwas found with the other considered cardiovascular risk factors.

P 010 CONFOCAL LASER SCAN MICROSCOPY (CLSM) FOR PO-TENTIAL MICROCAPSULE MEMBRANE CHARACTERIZATIONW. Ouyang, F. Afkhami, H. Chen, S. Prakash. Biomedical Technology andCell Therapy Research Laboratory, Department of Biomedical Engineeringand Artificial Cells and Organs Research Centre, Faculty of Medicine,McGill University, Montreal, QC, CanadaBackground/Aim: Confocal laser Scanning microscopy (CLSM) providesresearchers with the ability to optically section specimens that fluoresce orhave been tagged with fluorescent probes. This technology provides withvery high light microscope resolution obtainable. Previous applications ofCLSM on coarervating system studies used fluorescent markers to label thepolymers and thereafter identified their distribution by CLSM. The methodsof labeling include simply blending and covalently linking. In this study, forthe first time fluorescent marked coating materials and CLSM has been usedto detect APPPA microcapsule membranes thickness and other microcap-sule structural properties and compared with APA microcapsules. Method:Fluorescent marked membrane formulations were prepared. For this 0.1%FT-dextran (FD-2000, Mw = 2000 KD) with 0.1% PLL solution, 0.1% pectinsolution and 0.1% alginate solution were mixed in ratio of 1 : 9. 2 andAPPPA and APA microcapsule were prepared. Fluorescent marked micro-capsules were analyze using Zeiss LSM 510 Laser Scanning ConfocalImaging System (Carl Zeiss, Jena, Germany). The images were performedusing LSM 510 software. Results: Result shows CLSM can be applied tostudy microcapsule membranes. In particular in layer by layer microcapsulecan be analyzed. LSM analysis of the CLSM images reveals clear APPPAand APA microcapsules membrane microcapsule diameter and membranethickness. Results showed that the diameter of microcapsules: APPPA is 584 ± 8 mm,APA is 575 ± 20 mm; there are not big difference between APPPAand APA when prepared in same batches. Result shows that APPPA micro-capsule membrane has a thickness of 8.40 ± 1.56 mm in 10¥ magnificationsand 7.37 ± 1.0 mm in 40¥ magnifications. The APA, microcapsule membranethickness was found 5.40 ± 0.98 mm at 10¥ magnification and 4.82 ± 0.41 mmin 40¥ magnifications. The result shows that APPPA microcapsule is thickerthan the membrane of APA microcapsule. Conclusion: The membrane ofmicrocapsules was successfully visualized and analyzed under CLSM.

Polymers and Scaffolds 2

P 011 ELECTOSPUN NANOFIBROUS POLYURETHANE MEM-BRANE AS HEMOFILTRATION MEMBRANEH.G. Yoon1,5,6, K.S. Lee1,5,6, H. Choi1,6, J.H. Kim1,5,6, E.B. Shim2, B.G. Min3,4,5.1Interdisciplinary Program in Medical and Biological Engineering Major,Graduate School, Seoul National University, Seoul, 2Department ofMechanical engineering, Kangwon National University, Chuncheon,3Department of Biomedical Engineering, College of Medicine, SeoulNational University, Seoul, 4Institute of Medical Engineering, MedicalResearch Center, Seoul National University, Seoul, 5Cancer Research Insti-tute, Seoul National University, 6Korea Artificial Organ Center, Seoul,KoreaAim: This study introduces PU nanofibrous membrane prepared by elec-trospinning and is applied PU nanofibrous membrane to the experiment ofin vitro ultrafiltration. Methods: To measure Quf of PU Nanofibrous mem-brane, we have used distilled water as a simulated blood in this experimentand controlled the pressure of inner blood reservoir by occluding outlet ofthe simulated blood, as a result, TMP was occurred. Ultrafiltration rate ofdistilled water was measured through nanofiber membrane. Results: AtTMP, 50 mmHg, Quf value was around 100 ml/min in conventional hemofil-ter but in nanofiber hemofilter, the value of that was approximately 500 ml/min which is around 5 times bigger than conventional hemofilter.Conclusion(s): A nanofibrous PU membrane was prepared by electrospin-ning, and its performance as hemofiltration membrane was evaluated. Theuse of nanofibrous PU membrane was much less TMP value and much moreQuf value compared with conventional hemofilter. It will be a good appli-cation to the hemofiltration field in the further study.

P 012 DEVELOPMENT OF NOVEL DRUG-ELUTING MICRO-POROUS COVERED STENTS: COATING OF STATINY. Nakayama1, S. Nishi2, H. Ishibashi-Ueda3, M. Shiomi4, Y. Okamoto5.1Dept. of Bioengineering & 3Dept. of Pathology, National CardiovascularCenter, Osaka, 2Dept. of Neurosurgery, Takatsuki Red Cross Hospital,Osaka, 4Institute of Experimental Animals, Kobe University School of Med-icine, Kobe, 5Bridgestone, Yokohama, JapanPurpose: We have been developed covered stents with an open cell-struc-tured cover film immobilized with drugs for the next generation of drugeluting stents (DES). In this study, novel covered stents, in which its luminalsurface was immobilized with argatroban and its outer one was immobilizedwith simvastatin, were developed. Whether the stents prevent thrombus for-mation and neointimal hyperplasia after stenting is evaluated. Materials andMethods: Segmented polyurethane film was formed among the strut withpre-dilation of 2 mm in diameter by dip-coating method, subsequentlymicropored by laser processing (diameter; 0.1 mm, distance; 0.25 mm). Arga-troban (1 mg/cm2) for luminal surface, and simvastatin (0.14–1.4 mg/cm2) forouter surface were coated on the covered film from their methanol solu-tions. The stents mounted on a PTA balloon were deployed by dilation ofthe balloon (3 mm) in carotid arteries (diameter: 2.5 mm) from femoralarteries of Watanabe heritable hyperlipidemic (WHHL) MI rabbits (n = 4for each group). Results: Angiography immediately after implantationshowed that all arteries were patent with no sign of intraluminal defects. Atone month of implantation one half of covered stents without drug as acontrol group were occluded. On the other hand, in the drug coating group,all affected arteries were patent. Histological evaluation showed that fewinflammatory cells around the cover film and no significant neointimal thick-ening were observed. Luminal surface of the stents covered with confluentendothelial cells. Interestingly, drug eluting from the stents decreasedplasma cholesterol levels. Conclusion: The developed covered stents withdifferential drug-coatings of argatroban and simvastatin are effective in pre-vention of neointimal thickening with marked suppression of inflammatoryresponse.

P 013 DEVELOPMENT OF DRUG-ELUTING, SELF-EXPANDABLE COVERED STENTSY. Nakayama1, Y. Miura2, Y. Zhou1, K. Hayashida1, Y. Okamoto3,H. Ueda-Ishibashi4, T. Ishibashi2. Department of 1Bioengineering & 4Pathology, National Cardiovascular Center, Osaka, 2Department of Radi-ology,Tohoku University Graduate School of Medicine, Sendai, 3BrigestoneCo. Yokohama, JapanBackground: We have been developed balloon-expandable covered stentswith an open cell-structured cover film immobilized with drugs for the nextgeneration of drug eluting stents (DES). In this study, covered stents withself-expandability were newly developed. Materials and Methods: Coverfilm (10 mm) made of segmented polyurethane was formed around the strutof self-expandable NiTi stents (Sendai stent, diameter: 4–6 mm, length:20–30 mm, Piolax Co.) by dip-coating method, and subsequently the film wasmicropored by eximer laser ablation (pore diameter: 100 mm, pore interval:250 mm). After coating of FK506 (0.14 mg/cm2) on the outer surface of thecover film, the covered stents were mounted into an 8Fr delivery catheter,and were deployed in bilateral iliac arteries of beagle dogs (12 kg) fromcarotid arteries. Results: The covered stents were easily delivered from an8Fr delivery catheter without any tearing and delamination of cover film.Since the cover film was extremely thin the expanded shape of the stents wasmaintained with no shrinkage at room temperature. In addition, there was no breaking even upon curving the stents. The stents could be smoothlymanipulated in the blood vessels, and no differences in handling were notedirrespective of the presence of covering. After one month of implantationangiographs of all the stents showed patent with no significant intimal hyper-plasia. Histological evaluation showed that few inflammatory cells aroundthe cover film and no significant neointimal thickening were observed.

P 014 TISSUE RESPONSE TO NATURAL AND SYNTHETIC BIOMATERIALS: ANALYSIS OF THE EARLY PHASE TISSUEREACTION USING THE HET-CAM ASSAYC. Eder1,2, E. Falkner2,3, H. Schöffl2, S. Nehrer1, U.M. Losert3. 1Dept. ofOrthopaedic Surgery, Medical University Vienna, 2zet-Centre for Alterna-tive and Complementary Methods to Animal Testing, Linz, 3Core Unit forBiomedical Research, Medical University Vienna, AustriaBackground: Biodegradable scaffolds are crucial for transplantation oftissue engineered products. Animal models for scaffold evaluation usually

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cover the mid-term and late tissue reactions while the early phase tissueresponse is not documented. The HET-CAM test was used to compare theearly phase tissue reaction of a synthetic (Hyalograft C) and a natural scaf-fold (Chondrocell) material. Methods: Samples were applied onto the chori-onallantoic membrane of 7 days old fertilized and incubated chicken eggsand incubated for 3 days in ovo followed by digital documentation and his-tological analysis. Results: Samples were completely integrated into the con-nective tissue of the CAM and showed different degradation stages: TheHyalograft C scaffolds were disintegrated into single fibres while the Chon-drocell scaffolds maintained their original shape. The synthetic materialinduced an inflammatory tissue response and thrombus formation in singlevessels was observed. Fibrous tissue in the surrounding of the biomaterialshowed a beginning incapsulation of the implant. The normal CAM struc-ture was altered and atypical cells were observed. The collagen implant onlyprovoked a mild tissue response indicated by the presence of single lym-phocytes within the scaffold. CAM structure was not altered and atypicalcells or vessel thrombosis were not observed. Conclusion: Although thelong-term impact of these observations remain to be evaluated, CAMtesting is a valuable tool for short term analysis and intermediate in vitro/invivo biomaterial characterization.

P 015 EXTRACARDIAC CONDUITS IN CHILDREN: SUPERIORDURABILITY OF DECELLULARIZED SYNERGRAFTS TO STAN-DARD CRYOPRESERVED ALLOGRAFTSJ.W. Brown, M.M. Ruzmetov, M.D. Rodefeld, M.W. Turrentine. Section ofCardiothoracic Surgery, Indiana University School of Medicine, Indianapo-lis, IN, USA.Objective: The ideal choice for valved reconstruction of the right ventricu-lar outflow tract (RVOT) in patients is undetermined. The limited avail-ability and durability of cryopreserved allografts as extracardiac conduitshas led to the development and use of new conduits. The aim of this reviewis to evaluate the short-term follow-up after extracardiac RVOT recon-struction with a novel decellularized hom*ograft valve conduit (Syner-Graft,SG)(CryoLife) and compare it with standard cryopreservedpulmonary hom*ografts (CPH)(CryoLife) of the same size in a similar appli-cation. Methods: Between November 2001 and May 2004, 13 patientsreceived SG valved conduits for RVOT reconstruction. Preoperative diag-noses were: reconstruction of RVOT after previous tetralogy of Fallot orpulmonary atresia repair (n = 10), Rastelli operation (n = 2), and truncusarteriosus repair (n = 1). The mean size of SG conduit is 25 + 5 mm (range,12 to 30 mm). These 13 SG conduits were compared to 15 CPH conduitsimplanted since 2000. Results: All patients are well on follow-up from 2 to 44 months (mean 17.4 + 8.3months) with no deaths or reoperations.Echocardiography revealed mild or no pulmonary insufficiency (PI) in100% of patients. The calculated mean peak systolic RVOT gradient byechocardiography was 18.6 + 3.7 mmHg. One patient has right lower pul-monary artery branch stenosis with a peak gradient of 61 mmHg. A com-parison of outcomes of RVOT reconstruction with SG and CPH conduitson follow-up in non-Ross patients are shown.

P 016 CHANGES IN THE PORCINE PERICARDIUM STRUCTUREAFTER STABILIZATION WITH TANNIC ACIDA. Turek1, B. Cwalina1, Z. Nawrat2, J. Nozynski2. 1Dept. of Biophysics, Med.Univ. of Silesia, Sosnowiec; 2Foundation for Development of CardiacSurgery, Zabrze, PolandBackground: Tannic acid (TA) modifies extracellular matrix thus leading tostabilization of collagen-rich tissues. We searched possibility of enhance ofthe tissue structure integrity due to its cross-linking by TA, and simultane-ous prevention of the tissue natural features. Methods: The porcine peri-cardium tissues were treated with 2% TA water solution for 4, 24 and 48hours (temp. 4°C). Changes in structure stability were investigated usingSDS-PAGE electrophoresis. Gel was stained with silver. Electrophoregramswere analysed using software package Scangel 1.45 (Kucharczyk T.E. Co).Structural elements were observed in the light-microscope Polyvar 2 (Leica)under magnification 400¥. Tissues were stained with Harris haematoxylinand erythrosine (H&E) or aldehyde fuchsine. The preparation-documenta-tion has been performed using Quantament 500 Plus System. Results: TA-stabilization did not cause significant qualitative changes in electrophoreticprofiles as compared with native tissue. However, decrease in amounts ofpeptides extracted from modified tissues was noted. Although morpholog-ical elements seemed to be correctly prevented, changes in the TA-treatedtissues structure were observed under magnification 400¥. Elongation ofconnective fibres was visualised after H&E staining of tissues whereaselastic fibres indicated similar effect after staining with aldehyde fuchsine.Conclusions: TA-treatment of the porcine pericardium tissue results inhigher stability of its structure simultaneously allowing prevention of thetissue morphology.

P 017 DEVELOPMENT OF A NOVEL PASS-THROUGH ANTI-INFECTIVE CATHETER SYSTEMG. Gabel, K. Affeld, U. Kertzscher. Biofluidmechanics Laboratory, Clinic ofCardiovascular Surgery, Charité—Universitätsmedizin Berlin, GermanyBackground: In the context of spreading multi-resistant bacteria manyefforts are made to fight this development. Catheters with bioactive sub-stances lead to antibiotic resistance development which makes them effec-tive only for a short period of time. Objective of this study is to check thefeasibility of a new concept, which is the excretion of substances from thesurface of an indwelling catheter. This principle is successfully applied byamphibians, which constantly are threatened by biofilms. Biofilms are adefensive measure of microbes, which attach to a surface and create thisprotective layer. They are, however, defenceless on the side where theyattach. The new concept makes use of this by the perfusion of the microp-orous surface. Methods: Preliminary studies were conducted using a micro-porous lipophilic Polypropylene tube with 2 mm pore diameter. Gardenmould was used for inoculation of the tube surfaces. Flow of mineral oilwith rates of 15 and 150 ml/min were achieved by closing the distal tube endand attaching the proximal end to a roller pump. This was compared with2 additional experiments using either tap water perfusate or no perfusate.The biofilm development was assessed by alcian blue staining. Results:5-day experiments showed superior performance of the oil-perfused tubes.No biofilm was observed on their surface. Tap-water showed only minimalbiofilm reduction in comparison to non-perfused tube surfaces. Conclusions:These promising results encourage further pursuit of this approach. It isassumed that oil-perfusion through the lipophilic surface produces an oilfilm which firmly adheres to the catheter and forms an impenetrable barrieragainst microbes. Future studies will include a hydrophilic surface perfusedwith a water based substance possibly containing antibiotics. This wouldapply for a central venous catheter application. Accompanying evaluationof the potential of this concept to suppress specific biofilm maturation stageslike initial adhesion, colony-forming and polysaccharide-matrix generationwill be done.

P 018 ANASTOMOSIS OF ePTFE GRAFTS WITH RUNNING ORINTERRUPTED SUTURES: ANGIOGRAPHIC AND MORPHOMET-RIC RESULTSE. Khabiri1, M. Cikirikcioglu1, J.-C. Tille2, S. Da Cruz1, A. Kalangos1,B.H. Walpoth1. 1Department of Cardiovascular Surgery, University Hospital, Geneva, 2Department of Clinical Pathology, University Hospital,Geneva, SwitzerlandBackground/Aim: Vascular anastomoses are normally performed byrunning suture technique. Interrupted sutures may improve the compliancemismatch and reduce the purse string effect. The aim of this study is to

Medianpeak

Median Median RVOT PIage follow- gradient (moderate

(mo) up (mo) (mm Hg) or severe) Explant

SG 132 12 18.5 0 0(n = 13)

CPH 124 14 40 8 3(n = 15)

P = NS P = NS P = 0.03 P = 0.02 P = 0.05

Conclusions: These data demonstrate excellent results with the SG valveconduits for RVOT reconstruction in children and adults. The SG valve con-duits may serve as an available alternative for RVOT reconstruction forolder patients, particularly since early insufficiency is less severe. Questionsof long-term durability and significance of echocardiographic stenosisremain unanswered.

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compare the angiographic and morphologic effect of running versus inter-rupted sutures for the anastomosis of small diameter ePFTE grafts.Methods: Bilateral carotid artery graft interposition was performed in 6 pigs(ePTFE, 4 mm diameter). The 12 grafts were anastomosed either withrunning (n = 6), or interrupted (n = 6) technique with 7/0 polypropylenesuture. Selective carotid angiography was performed to evaluate anasto-motic stenosis after surgery and before sacrifice. At the end of the study (31 ± 3 days), the grafts were excised for histology and scanning electronmicroscopy. Computed morphometry was carried out to determine intimalhyperplasia at the anastomosis. Statistics were performed using MannWhitney U test. Results: At 1 month, all grafts were patent. Quantitativecarotid angiography (QCA) showed no significant difference between thetwo groups postoperatively early and late (Table). However, the runningtechnique showed a trend for more stenosis and more pronounced increasefrom the early to the late angiogram. This is also reflected by the intimalhyperplasia formation. Conclusions: Patency rate was excellent and similarin the running and interrupted suture technique of ePTFE grafts. Angiog-raphy showed only a trend to more purse string effect which increased bytime with intimal hyperplasia. Thus, interrupted suture technique may beuseful to limit stenosis and intimal hyperplasia at the anastomosis of smallsynthetic vascular grafts. P 020 SUTURELESS VASCULAR ANASTOMOSES USING A

BIODEGRADABLE STENTY. Nakano1,2, Y. Hori1, A. Sato2, T. Watanabe2, S. Takada2, H. Goto2,A. Inagaki1, S. Satomi2. 1Tohoku University Biomedical EngineeringResearch Organization, 2Division of Advanced Surgical Science and Tech-nology, Graduate School of Medicine, Tohoku University, Sendai, JapanBackground/Aim: We previously reported a sutureless anastomotic devicewith a nitinol stent to reduce the technical demands of vascular anasto-moses. We therefore hypothesized that the use of a biodegradable stentwould be preferable because the stent would disappear leaving nothing inthe lumen. The aim of this study was to evaluate the feasibility and efficacyof a new sutureless anastomotic device with a bioabsorbable stent in swinemodels. Methods: The abdominal aorta of a pig was resected over a 2 cmlong portion and then was reconstructed by an end-to-end anastomosisusing an expanded polytetrafluoroethylene (ePTFE) graft. The proximalanastomosis was carried out with a poly (L-lactic acid) (PLLA) stent. Distalanastomosis was performed with a 6–0 polypropylene running suture ascontrol. At 4 weeks after surgery, angiograms were done, and the animalswere sacrificed and evaluated histologically. Results: This sutureless anas-tomotic procedure required much less time than traditional suturing tech-niques. An angiogram showed the patency of the graft, and no sign of eitherstenosis or leakage. A histological examination confirmed the healing of theaorta to the graft with minimal neointimal hyperplasia. The PLLA stent stillremained in the neointima at this time point. Conclusion(s): Suturelessanastomosis with a PLLA stent appears to be a feasible and effectivemethod. Further studies with more cases and long-time follow-up are nec-essary for future clinical application.

Dialysis

P 021 EFFECT OF THE HFR ON-LINE TECHNIQUE ON hom*o-CYSTEINE PLASMA LEVELS: CORRELATION WITH NUTRI-ONAL-INFLAMMATORY STATUSS. De Angelis°, M. Dessì1, M. Ferrannini°, A. Naticchia°, G. Splendiani°.°Nephrology and Dialysis Service, 1Department of Laboratory Medicine,University Hospital “Tor Vergata” Rome, ItalyBackground: Total plasma hom*ocysteine (tHcy) is grossly elevated in HDpatients, related to a hypothesized defective Hcy renal metabolism, as well asto the loss of water-soluble vitamins in the dialysis fluid. Besides folic acidtherapy and vitamin B12 supplementation both fail to normalize tHcy levelsin the majority of patients. Procedures using diffusive techniques have showna poor influence on tHcy levels. More effective resulted the procedures usingthe hemodiafiltration (HDF) techniques, such as acetate free-biofiltration(AFB), and high-flux or super-flux dialyzers. Analogous better results we achieved using Hemodiafiltration reinfusion (HFR) on line (doublechamber hemodialfiltration with regenerated ultrafiltrate reinfusion).Methods: Our aim was to observe the effect of the HFR on line technique on removing Hcy and the possible correlation with nutritional-inflammatorystatus in 61 HD patients,(M/F = 32/29), with a mean age of 49.5 ± 7.4 years,and dialytic age of 28.5 months (range 8 to 144).As for dialysis procedures 40 patients were undergoing standard diffusive hemodialysis, while 21 wereundergoing HDF techniques (10 on AFB and 11 on HFR on line). tHcy

1 mm grafts 2 mm grafts(n = 8) (n = 8)

P

Patency 7/8 8/8 NS

Flow (ml/min) 14 ± 1 13 ± 1 NS

Proximal aorta 103 ± 8 114 ± 13 NS(% diameter)

Middle graft 57 ± 6 98 ± 4 0.001(% diameter)

Distal aorta 78 ± 4 94 ± 9 0.005(% diameter)

Intimal hyperplasia 11 ± 9 10 ± 16 NS(mm2/mm)

Endothelial coverage 440 ± 233 659 ± 239 0.008(mm)

P 019 IMPROVED ENDOTHELIALISATION IN WELL MATCHEDePTFE GRAFTSM. Cikirikcioglu1, Y.B. Cikirikcioglu1, J.-C. Tille2, A. Kalangos1,B.H. Walpoth1. 1Department of Cardiovascular Surgery, University Hospital, Geneva, 2Department of Clinical Pathology, University Hospital,Geneva, SwitzerlandBackground/Aim: Intimal hyperplasia and endothelialisation correlateinversely with shear stress and flow characteristics. Therefore, mismatchbetween native artery and graft diameter may affect intimal hyperplasia for-mation and endothelial coverage. The aim of this study is to compare mis-matched (1 mm) and well matched (2 mm) ePTFE grafts after implantationin the rat abdominal aorta with regard to angiographic dimensions and mor-phologic changes. Methods: In 16 male Sprague Dawley rats (415 ± 60 gr),1 mm (n = 8) and 2 mm ePTFE (n = 8) grafts were interposed in theinfrarenal abdominal aorta. The proximal and distal anastomoses were per-formed with 10/0 interrupted nylon sutures with an operative microscope.Anastomosis quality was evaluated intra-operatively with a transit timeflowmeter. Animals were followed for 3 weeks and angiography was per-formed via right carotid artery before sacrifice. We measured midgraft, prox-imal and distal aorta diameters using quantitative abdominal aortography(QAA). Grafts were then harvested for computed morphometric analysis.Statistics were performed using Mann Whitney U test. Results: Intraoper-ative flow amounts were similar for two groups. After 3 weeks of implan-tation patency rate was 87% and 100% for 1 mm and 2 mm ePTFE grafts,respectively. Graft diameter was significantly smaller for 1 mm compared to2 mm grafts (Figure). Intimal hyperplasia was similar for both groups butendothelial coverage was significantly better in well matched 2 mm grafts(Table). Conclusions: In well-matched grafts we find a significantly betterendothelialisation. This may influence long-term results despite early similarpatency rates.

Interrupted RunningP

(n = 6) (n = 6)

Anastomotic stenosis at 21 ± 2 29 ± 10 0.108early angiography (%)

Anastomotic stenosis at 25 ± 9 35 ± 10 0.096late angiography (%)

Intimal hyperplasia 169 ± 100 241 ± 172 0.281(mm2/mm)

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levels concentrations was determined using HPLC. PCR amplification ofDNA was performed for the caracterization of the C677-TT genotypes.Prognostic inflammation nutritional index (PINI) was assessed to accountfor inflammation and/or malnutrition. Results: The genotype frequency were 0.30, 0.54 and 0.16 for CC, CT and TT carriers respectively. The corre-sponding mean Hcy levels in mmol/L were 29.7 ± 4.5, 68.5 ± 9.8, 112.7 ± 37.8.After a month tHcy levels were lower in the AFB and HFR groups, in spiteof similar MTHFR genotype, compared to HD standard group. About thecorrelation between PINI values and dialysis procedure 13 patients (32.5%)undergoing standard HD have a pathological PINI (PINI > 1), whereas all 11patients on HFR have normal PINI, such as 7 patients on AFB. Conclusions:HFR on-line seems to be the only hemodiafiltration able to reduce tHcylevels in HD patients more effectively than other techniques, perhaps reducing micronutrients loss and influencing a lower inflammatory responseof the patient to the dialytic procedure.

P 022 REMOVAL OF LOW MOLECULAR WEIGHT TOXINS WITH INTERMEDIARY ON-LINE HEMODIAFILTRATION (MID-DILUTION HDF)L. Bibiano, P. Freddi, G. Gaffi, A.M. Ricciatti, G.M. Frascà. Nephrology,Dialysis and Transplantation Unit,“Ospedali Riuniti” Hospital,Ancona, ItalyBackground/Aim: It’s has been shown that HDF increases the cardiovas-cular stability and decreases morbility and mortality thanks to a betterremoval of a vast range of uremic toxins. Since both “pre” and “post” HDFhave several disadvantages, the Mid-Dilution technique (MD HDF) hasbeen proposed with the aim of performing both “pre” and “post” HDF withthe same device. The present cross-over randomized study compares theeffectiveness of MD-HDF vs a high flux-HD. Methods: Ten patients havebeen treated for two weeks with medium-flux HD (MF-HD). Then theywere randomized in two groups: a) High-flux bicarbonate HD; b) MD-HDF.After 8 weeks of treatment the pts were treated for 8 additional weeks withthe other technique. B2-microglobulin, urea, creatinine and phosphoruswere evaluated at the beginning of the study and at the end of each periodof treatment. Results: The removal% of b2-microglobulin proved signifi-cantly higher (p < 0.05) by the MD-HDF (71 + 8) as compared to the HF-HD (61 + 4). No significant difference for the removal of urea, creatinin andphosphorus was observed between the two techniques. Conclusions: Theexclusive configuration of the dialyzer for MD-HDF allows to perform ahigh efficiency HDF with a meaningful improvement in the removal ofmiddle molecules.

P 023 UREMIC TOXIN REMOVAL AND ALBUMIN LOSS INPREDILUTION ONLINE HEMOFILTRATION: COMPARISON OFMEMBRANE SELECTIVITYV. Giancaspro, V.A. Lozupone, M. Bozzi, F. Petrarulo. Struttura complessadi Nefrologia e Dialisi, Ospedale Di Venere, Bari, ItalyPurpose: On-line predilution hemofiltration (HF) is applied for treatingESRD patients to improve hemodynamic stability, but also to enhance theremoval of middle molecule uremic toxins, e.g. b2-microglobulin (b2m; MW12kD) and complement factor D (fD; MW 24kD). The removal of solutesby HF depends on the blood and filtration flow rates but also on the hemofil-ter sieving characteristics. We compared the removal of urea, b2M and fDin predilution HF, and the possible loss of albumin, by two synthetic high-flux dialyzers with membranes made of similar polymers and having com-parable surface areas. Methods: In a short-term cross-over study design, 8stable patients (age 41–75 y, BW 50–67 kg) were treated with predilution HF(AK200ULTRA) using Polyflux 210H (2.1 m2, Gambro) and FX100 (2.0 m2, Fresenius) dialyzers in randomized order. Treatment time, Qb, andsubstitution fluid infusion rate were similar, being 348 ± 4 ml/min, 236 ± 10min, and 19 ± 2 L/h respectively. Filtrate samples were collected by using asplit-flow technique. B2m was measured by nephelometry, fD by ELISA,and albumin by immunonephelometry. Results: Solute removal character-istics (mean ± SD) are summarized in the table.

Polyflux 210H FX 100 PUrea reduction, % 62 ± 6 59 ± 9 n.s.B2m reduction, % 78 ± 4 77 ± 4 n.s.B2m mass removed, mg 186 ± 30 189 ± 29 n.s.fD mass removed, mg 26 ± 9 18 ± 6 0.002Albumin mass lost, g 1.3 ± 0.7 2.6 ± 1.8 0.006ratio b2m/albumin, ¥10–3 174 ± 77 107 ± 78 —ratio fD/albumin, ¥10–3 23 ± 9 9 ± 5 —

Conclusions: The two filters provided similar removal of urea and b2m. Agreater removal of factor D by the Polyflux filter, together with a lower lossof albumin, indicates that the asymmetric three-layer structure of thePolyflux membrane (based on polyamide/polyarylethersulfone) offersgreater sieving selectivity than the uniform sponge structure of the FX100polysulfone membrane. This may have important implications in the searchfor optimal removal of large uremic solutes by convective therapies, avoid-ing a possibly harmful loss of albumin.

P 024 USE OF OXYGENATED DIALYZING FLUID WITH PUL-STILE PUMP SYSTEMK.H. Lee1,4,5, B.G. Min2,3,4,5. 1Interdisciplinary Program in Medical and Bio-logical Engineering Major, Graduate School, Seoul National University,Seoul, 2Department of Biomedical Engineering, College of Medicine, SeoulNational University, Seoul, 3Institute of Medical and Biological Engineer-ing, Medical Research Center, Seoul National University, Seoul, 4CancerResearch Institute, College of Medicine, Seoul National University, Seoul,5Korea Artificial Organ Center, KoreaBackground: One of the major problems in the operation of hemodialyzerfilter process is hemodialyzer membrane fouling. During hemodialysis thereis a tendency for the hemodialyzer membrane fouling phenomenon tooccur. In order to decrease the fouling phenomenon in hemodialyzer mem-brane, a novel oxygenated dialyzing fluid process was proposed and evalu-ated by various tests with a pulsatile flow pump. Methods: Positive andnegative pressure pulses with an appropriated waveform, are produced bya pulsatile flow pump system (T-PLS). The dialysis sessions were performedwith T-PLS system. The oxygenated dialyzing fluid was injected to agitatethe hemodialyzer membrane. The dialysate fluid and oxygenated dialyzingfluid were pumped through the hemodialyzer membrane. The oxygenateddialyzing fluid was injected unidirectional flow with micro agitationmachine. Results and Conclusions: This study was designed to examine theprocess of oxygenated dialyzing fluid and blood during hemodialysis in apulsatile flow pump. The oxygenated dialyzing fluid processes by which thisreduced fouling phenomenon and the improved hemodynamics are affectedare being evaluated. The functional relation between oxygenated dialyzingfluid and blood of hemodialyzer was interested, these results implicate oxy-genated dialyzing fluid with micro agitation machine, particularly pulsatilepump (T-PLS), as the hemodialyzer membrane property significantlychanged in hemodialysis.

P 025 OXIDATIVE STRESS IN HAEMODIALYSIS PATIENTS: ACOMPARISON OF THREE DEPURATIVE TECHNIQUESS. Palleschi1, S. De Angelis2, G. Severini1, L. Diana1, B. Rossi1, V. Papa1,G. Splendiani2. 1Dept of Nephrology and Dialysis, Tor Vergata University,Rome, 2Dept of Hematology, Oncology and Molecular Medicine, IstitutoSuperiore di Sanità, Rome, ItalyBackground/Aim: Oxidative stress (OS) has been implicated in the devel-opment of long-term complications in haemodialysis patients. The aim ofthis study was to critically evaluate established and emerging biochemicalevidences of OS in patients on different depurative treatments. Methods:Vitamin A (VitA), E (VitE) and C (VitC), uric acid (AU), reduced thiols(SH), plasma antioxidant potential (BAP and OXYAds, commercial kits),malonyldialdehide (MDA), lipid hydroperoxides (d-ROMs, commercialkit), proteins, cholesterol and triglycerides have been analyzed in 31 patientson bicarbonate-haemodialysis (HD, n = 10), hemodiafiltration (HDF, n = 10)or peritoneal dialysis (PD, n = 11). Results: An imbalance between lipophilicand hydrophilic antioxidant factors was found, as witnessed by high VitA,normal VitE and low VitC and SH levels in all the subjects. However, plasmaantioxidant potential was not impaired and it was significantly related eitherwith VitA (rs = 0.363) and VitE (rs = 0.414). Though all patients showed highMDA levels, d-ROMs values were significantly increased only in DPpatients, with HDF patients showing significantly lower values. Dialysis pro-cedure did not modify both VitA and VitE levels but it significantly affectedVitC (-46%, -46% in HD and HDF, respectively), AU (-72, -77%), SH(+45%, +51%), BAP (-14%, -17%), MDA (-14%, -20%) and d-ROMs(+17%, +21%). Significant correlations were found between MDA and d-ROMs (rs = -0.410) and MDA and VitA (rs = 0.388). Conclusions: Theseresults indicate that non-enzymatic, plasma antioxidant potential is not sig-nificantly impaired in haemodialysis patients and that lipophilic factors playa key role in the antioxidant defence. Plasma lipid peroxidation (LPO)decreases by increasing dialysis efficiency (PD > HD > HDF) suggesting thepresence of high-MW pro-oxidant solutes. Nonetheless, plasma redox status

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is altered mainly due to diffusible, low-MW solutes. MDA level reliabilityas an index of LPO in uremia is also questioned.

P 026 SMARTCAT: A NEW DOUBLE LUMEN HIGH FLOW CEN-TRAL VENOUS CATHETER. THE FUTURE IN HEMOFILTRATIONI. Mallabiabarrena1, G. Mucciolo1, A. Mucciolo1, S. Taub2, L.K. vonSegesser1. 1Cardiovascular Surgery Department, CHUV, Lausanne, 2CorafloLLC, Lausanne, SwitzerlandBackground: central venous catheters (CVC) have been in wide used astemporary or long term means of vascular access in hemofiltration. In recentyears, the increasing number of patients with acute need for dialysis haswidened the market for CVC, promoting competition and improvedcatheter design Moreover, the demand of high flow rates for CVC hasincreased in the era of high-flux dialysis. The double lumen SmartCat CVCprototype, is based on a self-expanding structure. The technology owned byCoraflo LLC (http://www.coraflo.com) has already proven better per-formance in cardio-vascular applications. Therefore, SmartCat CVCs willprovide lower arterial and venous pressure drop vs. blood flow rate ratio(DP/Q), for a given vascular access aperture. Methods: we have comparedpressure drop/blood flow ratio in SmartCat 11.5F ¥ 15cm prototypes (n = 3)against concentric double lumen (n = 3) Standard 11.5F ¥ 15cm CVCs avail-able in the market. Arterial (inflow) and venous (outflow) pressure valueswere measured and monitored in a continuous way for different liquid flowrates. Pressure and blood flow rates were measured at pump speeds from50 to 600 ml/min in increments of 100 ml/min. Experiments using water asliquid phase were carried with an in-vitro bench. These CVCs were alsotested using blood as liquid phase. That for, catheters were implanted for ashort time in the left jugular vessel of an animal, corroborating the betterperformance of SmartCat prototypes. Results: following table shows liquidflow rate (Q [ml/min]) vs. arterial (DPa) and venous (DPv) pressure drop[mmHg] averaged values for in-vitro tests with water.

no capsules and d) “empty” capsules containing neither activated charcoalnor bacteria. Results: Microcapsules containing activated charcoal and liveL. acidophilus bacterial cells showed the largest decrease in creatininelevels, from 0.63 mmol/L to 0.31 mmol/L in 48 hours. Capsules containingonly L. acidophilus showed a modest decrease of creatinine from 0.73 mmol/L to 0.54 mmol/L, while the “empty” capsules showed slightdecrease due to diffusion kinetics and entrapment, reducing creatinine from0.66 mmol/L to 0.55 mmol/L. Conclusion: Previous literature reports thatactivated charcoal adsorbs creatinine. This adsorption capacity may beamplified by its combination with L. acidophilus. These results establish thepossibility of combining live bacterial cells and adsorbent as a potentialadjunctive therapy for renal failure patients. Further research however isrequired.

P 028 ASCITES-APHERESIS: A NEW AUTOMATIZED DEVICEFOR ULTRAFILTRATION AND REINFUSION OF REFRACTORYASCITES IN CIRRHOSISS. Landini*, F. Bortoluzzi, D. Tempesta, A. Vitalba, A. Saggioro. *Depart-ment of Nephrology, Umberto I°Hospital Venice-Mestre, Department ofGastroenterology, Umberto I°Hospital Venice-MestreBackground/Aim: Ascites is a common complication of chronic liverdisease. Large volume paracentesis is a common, safe and effective, but oldand not refined treatment. The administration of albumin is recommendedto prevent hyponatremia, hypovolemia and renal insufficiency, but is enableto restore all proteins drained; is expensive and potentially infective. Rein-fusion of concentrated ascites has been demonstrated safe and effective.Many attempts have been made in order to develop simple and safe pro-cedures for recovery proteins loss. Several technical drawbacks and someclinical complications hindered long term experience. Methods: A newdevice, LIVE-SMART (Medica), planned for extracorporeal ultrafiltrationand completely automatized, draws the ascitic fluid through a polisulphonhemofilter (Medisulfone). H2O and salts are removed; proteins, becomingmore and more concentrated, are collected in a steril bag and reinfuse inperitoneum or in vein. 4 pts with refractory ascites and 2 pts with recurrentascites were treated. Results: We performed 56 treatments removing anaverage of 7.76+/-0.58 liters, 634 mEq NA+ and the mean amount of of pro-teins reifused was 29+/-4 gr. The mean time to fit out the Live-Smart was 8 min and 125 min for the whole procedure. Ultrafiltration was successfullyand easy conducted in all patients. No significant differences were detectedin hepatic function tests and coagulation parameters, platelets count hemo-globin levels. The urine output increased in spite of reduction of 50% ofFurosemide. A transient decrease in mean arterial pressure and pyrexia (3cases) were observed. The cost of the procedure is similar to the infusion ofcommercial albumin. Conclusions: Ascites concentration and reinfusion isa safe and effective treatment. LIVE_SMART, as completely automatized,makes the procedure easier, safer, faster and feasible for repeated chronicambulatory treatments.

P 029 “WRITING TECHNIQUE” AND COMPLIANCE TO TREAT-MENT IN REGULAR DIALYSIS TREATMENT (RDT) PATIENTSF. Selloni1, L. Solano2, P. Freddi1, A.M. Ricciatti1, L. Bibiano1, G. Gaffi1,G.M. Frascà1. 1Nephrology, Dialysis and Transplantation Unit, “OspedaliRiuniti” Hospital, Ancona, 2Dynamic and Clinical Psychology Department,“La sapienza” University, Roma ItalyBackground/Aim: Aim of this study was assess the efficacy of James Pen-nebaker’s writing technique to improve compliance to treatment in hemodi-alyzed patient with different levels of alexithymia and different attachmentstyles. This simple, inexpensive and fast method already proved effective inother clinical settings but has not been tested in RTD pts. Methods: Duringclinical setting in the period October 2004-April 2005, 19 patients on RDTwere divided into two groups: Group 1, 10 pts underwent: a) self-providingquestionnaire (ASQ,TAS 20, SCL 90); b) expressly drawn-up form in orderto point out dialytic parameters required for the study; c) three writing ses-sions during three consecutive dialysis. Group 2: 9 pts used as control under-went procedure a) and b) only. Results: The patients showed on average, ainsecure outdistance attachment style, with medium-high alexithymia scoreand a trend to increase over time. Writing technique failed to improve thecompliance to treatment in our pts. Conclusions: Several factors may havecontribute to these results and the study needs to be extended to a widernumber of pts.

Artif Organs, Vol. 29, No. 9, 2005

ml/ SmartCat Standard CVCmin 11.5F ¥ 15 cm 11.5F ¥ 15 cm

Q DPa [mm Hg] DPv [mm Hg] DPa [mm Hg] DPv [mm Hg]

50 -4.9 7.27 -1.86 10.2 ± 1.8

300 -55.24 ± 3.8 44.18 ± 1.3 -78.8 ± 1.2 76.5 ± 0.9

600 -170.8 ± 2.91 122.13 ± 3.2 -217.5 ± 0.3 216 ± 0.5

Conclusions: in-vitro benchmarking clearly shows the outstanding perfor-mance of the SmartCat CVC when compared to standard catheters. Smart-Cat allows a higher blood flow rates for a given pressure drop values, whichallows for shorter blood filtration sessions, thereby reducing overall cost oftreatment.

P 027 ACTIVATED CHARCOAL AND PROBIOTIC BACTERIA INMICROCAPSULES FOR CREATININE REDUCTION—ADJUNCTTHERAPY FOR KIDNEY FAILURET. Halim, W. Ouyang, H.M. Chen, C. Martoni, F. Afkhami and S. Prakash.Biomedical Technology and Cell Therapy Research Laboratory, Dept. ofBiomedical Engineering and Artificial Cells and Organs Research Centre,Faculty of Medicine, McGill University, Montreal, CanadaBackground: This project revisits conventional methods of oral administra-tion of biochemically active particles as an adjunct therapy in kidney failure.Current therapeutic protocols in kidney failure such as dialysis and perfu-sion methods entail side effects, compromise the quality of life of kidneyfailure patients and are time consuming. Prolonging inter-dialytic intervalsmay potentially be achieved with oral delivery of uremic adsorbents in com-bination with probiotic bacteria that had been conditioned for urea metab-olism. The uremic analyte of interest is creatinine. Methods: USP gradeactivated charcoal and Lactobacillus acidophilus were microencapsulated inCalcium-alginate capsules and coated with 0.5% (w/v) chitosan membrane.The capsules were then immersed in a gastric intestinal model simulatingconditions of the small intestine containing additional uremic waste. Thesupernatant is periodically sampled over 48 hours and analyzed for creati-nine concentrations. Comparisons were made between microcapsules containing a) L. acidophilus, and b) activated charcoal and bacteria L.acidophilus. Two negative controls set up include: c) gastric fluid containing

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P 030 DEVELOPMENT OF AN IMMUNOADSORPTION WALLFOR THE PREVENTION OF DIALYSIS RELATED AMYLOIDOSISY. Tsung-Hua. Department of Chemical Engineering, Cheng Shiu Univer-sity, Kaohsiung, TaiwanA stationary phase based on polyacrylamide is a suitable matrix for animmunoadsorption wall. In order to produce a functional stationary phase,we have developed a partially incomplete two-stage polymerization methodto immobilize immunoadsorbent on the exterior surface of a polyacry-lamide gel phase. Preliminary in vitro investigations using anti-beta-2-microglobulin antibodies have shown effective removal of the representative middle molecular weight toxin, i.e., beta-2-microglobulin.Thus, it is of promise to prevent or halt the progress of the dialysis relatedamyloidosis by application of such an immunoadsorption wall. In addition,it is also anticipated that the immunoadsorption wall could be tailored toperform versatile tasks for blood purification.

P 031 MASS-FRACTAL CARBONIC PYROPOLYMERS FORREMOVAL OF TIGHTLY PROTEIN-BOUND TOXINSV.G. Nikolaev, V.V. Sarnatskaya, L.A. Yushko, A.S. Sidorenko,K.I. Bardakhivskaya, A.V. Nikolaev. Institute of Experimental Pathology,Oncology and Radiobiology NAS, Kiev, UkraineActivated charcoals are well-known as a potent material for removal offree-diluted and protein-coupled substances from blood plasma and wholeblood. Nevertheless tightly albumin-bound “hepatic” and uremic toxins like unconjugated bilirubin (UB) and 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF) having association constants of the order of106–108 M-1 still remain practically unaccessible for hemocarboperfusiontechnique as well as for modern dialysis and ultrafiltration. In this presen-tation the new type of carbonic adsorbents—carbonic pyropolymers (CP)with mass-fractal structure of their internal surface describing as a crossec-tion of multilayer nano-tubes have been compared with convential syntheticactivated carbons for the removal of protein-bound metabolites from syn-thetic mixtures and whole plasma. It was demonstrated that in parallel withenhancement of the fractality level evaluated with Small Angle NeutronScattering (SANS) the capacity of CP towards UB removing from albumin-containing media is growing 0,7–98 mg/g correlating with the sharp increas-ing of CMPF, indoxyl sulphate, hippuric acid, phenols, bile acids andproinflammatory cytokines adsorption. Micro-calorimetric studies ofhuman serum albumin extracted from blood plasma of patients with heavyforms of hepatic and renal insufficiency demonstrated an essential restora-tion of normal molecular conformation and complex-forming function ofthis plasma protein due to the effective removal of albumin-bound ligandsfrom blood plasma or whole blood perfusion through mass-fractal carbonicpyropolymers.

Heart

P 032 DESIGN AND IMPLEMENTATION OF ACTUATOR HEADOF CARDIOPULMONARY BYPASS PUMP, T-PLSH. Choi1,4,5, H.G. Yoon1,4,5, D.W. Lee1,4,5, K.H. Lee1,4,5, B.G. Min2,3,4,5,6. 1Inter-disciplinary Program in Biomedical Engineering Major, Seoul National University, Seoul, 2Department of Biomedical Engineering, College of Medicine, Seoul National University, Seoul, 3Institute of Medical Engineer-ing, Medical Research Center, Seoul National University, Seoul, 4KoreaArtificial Organ Center, Seoul, 5Cancer Research Center, Seoul NationalUniversity Hospital, 6NewheartBio. Co., Ltd., Dongan-Gu, Anyang-Si,Gyeonggi-Do, KoreaAim: A new pulsatile, portable cardiopulmonary bypass system (T-PLST,NewheartBio, Korea) has been developed and it generates a physiologicpulsatile blood flow without another device. A pulsatile flow is produced byactuator pendulum speed (rpm) periodically. However, there is a concernthat the previous actuator head causes too much fatigue stress on the bloodsacs (Silicone tubing) of Pump pack. Also, more blood output volume isrequired. Methods: Thus, New designed actuator head was applied to theblood sac and tested. To determine silicone tubing pressure internalsresponse, and structural integrity, simulation was performed by FiniteElement Method. Finally, real teat was done to compare the previous oneand the new one in terms of blood sac life span and blood output volume.Results: Experimental and Simulation results were compared so that theperformance of the new designed actuator head was better than that of theprevious one. Conclusion: the fatigue stress on the blood sac was dramati-

cally decreased and blood output volume was reasonably increased by thenew designed actuator head.

P 033 DEVELOPMENT OF A NEWLY-DESIGNED ARTIFICIALMYOCARDIAL ASSIST DEVICE USING BIOMETALY. Shiraishi1, T. Yambe1, K. Sekine1, N. Masumoto2, J. Nagatoshi3, S. Itoh3,E. Okamoto4, Y. Saijo1, Q. Wang1, H. Liu1, S. Nitta1, S. Konno1, D. Ogawa5,P. Olegario5, M. Yoshizawa5, M. Higa5, A. Tanaka6, H. Miura5, F. Sato5,M. Uematsu3, T. Tanaka3, Y. Park3, T. Fujimoto7, K. Tabayashi5, H. Sasada5,M. Umezu3 and D. Homma6. 1Institute of Development, Aging and Cancer,Tohoku University, Sendai, Japan, 2Nippon Institute of Technology, Saitama,3Waseda University, Tokyo, 4Hokkaido-Tokai University, Sapporo, 5TohokuUniversity, Sendai, 6f*ckushima University, f*ckushima, 7Shibaura Instituteof Technology, Tokyo, 8Toki Corporation, Tokyo, JapanAim: The authors have been developing a newly-designed totally-implantable artificial myocardium using a covalent shape-memory alloyfibre (Biometal, Toki Corporation), which is attached onto the ventricularwall and is also capable of supporting the natural ventricular contraction.Methods: The alloy fibre was employed and an artificial myocardium wasfabricated. The prototype structure of the device was designed based on“parallel link” mechanism which was capable of controlling displacementaccurately. The fibre was driven by Joule heating synchronising with naturalventricular contraction. Results: Hemodynamic functions were examined in a mock circulatory system as well as on animal experiments in goats.Mechanical contraction was achieved against the afterload of 80 mmHg ina mock system and the increase of the cardiac function was also observedin hircine. Conclusion: The material of the fibre has a long durability per-formance against cyclic contraction for over 1 billion cycles because of itsnano-structure composed of the matrix of Ni-Ti alloy crystal. Then it wassuggested that the newly-developed artificial myocardium might be effec-tive for cardiac support from the outside of heart.

P 034 A NEW MYOSTIMULATOR AVOIDING MUSCLE FAILUREFOR MUSCULAR CARDIAC ASSIST?P. Klapproth1, J. Otten2, T. Büter2, R. Schirmer2, P. Maczinowski2,M. Großherr3, H.H. Sievers1, N.W. Guldner1. 1Clinic of Cardiac Surgery,University Lübeck, 2Faculty of Applied Science, University of AppliedScience, Lübeck, 3Clinic of Anaestesiology, University Lübeck, GermanyBackground/Aim: In the field of muscular cardiac assist, one major problemis the increasing inefficacy of muscle by frequent usage and muscular failure;inefficacy due to electrical induced muscle fiber transformation into slowand weak type-I fibers and muscular failure seen as fatty degeneration. Aimis the development of a new myostimulator, which maintains muscle’s fasttwitching fibers (type-II) and power delivery over time and the avoidanceof destruction. Methods: The fully implantable myostimulator consists,beside of standard analogue & digital circuits, of two microcontrollersrunning with in C language written software. Additionally, the implant isequipped with a RF telemetry module for transcutaneous communi-cationwith a patient control unit. Results: Myostimulator’s software is designedto prevent the permanent usage of muscle. Therefore a stimulation historytable of the last hours is build and mean stimulation rate is calculated. Ifmean stimulation rate exceeds a predefined boundary, the software reactsa.) by reducing the amount of stimulation impulses per stimulus and b.) bygiving telemetrically this information to patient’s control unit with the aimthat patient reduces physical activity. Conclusion: A new myostimulator isdesigned to evaluate, if muscle’s fast twitching fibers (type-II) got main-tained and muscular failure could become avoided. In this approach, thetotal amount of muscle stimulation per day got reduced; an on-demand stimulation followed by phases of rest is regarded as sufficient to maintainmuscle’s power delivery over time.

P 035 A NOVEL DEVELOPMENT OF A NEWLY PERCUTANEOUSSYSTEM FOR IMPLANTABLE VAD SYSTEM IN THE DESTINA-TION THERAPYT. Mizuno1, E. Tatsumi1, Y. Nemoto2, Y. Nakayama3, S. Saito2, Y. Okamoto2,T. Tsukiya1, Y. Takewa1, A. Homma1, S. Kitamura1, Y. Taenaka1. 1ArtificialOrgans, National Cardiovascular Center Research Institute, 2ChemicalProducts Division, BRIDGESTONE Co., 3Bioengineering, National Car-diovascular Center Research InstituteDriveline infection is a serious major problem for the patients with animplantable VAD system. They are important points for preventing this typeof infection to secure the percutaneous devices to the subcutaneous tissue

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and to close the skin at the exit site. We developed the novel percutaneoussystem to connect between an outer surface of percutaneous driveline andsubcutaneous tissue for encouraging subcutaneous tissue ingrowing, aimingto destination therapy using implantable VAD system. This system mainlyconsists of porous segmented polyurethane with the three-dimensionalreticulated structure, has tissue-like flexibility and sufficient mechanicalstrength. In the manufacturing process, these porous diameters are freelycontrolled between 0.2 and 1.0 mm. The purpose of this study was to inves-tigate tissue-compatibility of this newly material. The test materials whichinserted into the silicon tubes (these porous diameters were 500, 300, 150,and 50 micrometer) implanted into subcutaneous tissue of an adult goat.After 30 days implantation, we extirpated all samples and investigatedpathologically. The lengths of the granulated tissue which infiltrated into thetest tube were 7.2 ± 1.2, 6.6 ± 0.6, 5.4 ± 0.9, and 4.0 ± 0.7 mm (n = 5). Eachinfiltrated tissue included the mature connective tissue and the neovescu-larization, and did not include inflammatory or necrotic foci in the test tubes.In conclusion, the newly developed material may be a suitable to connect-ing method between the percutaneous driveline and subcutaneous tissue fordestination therapy with implantable VAD system.

P 036 DESIGN OF BLDC MOTOR CONTROLLER WITH INSTAN-TEOUS TORQUE CONTROL FOR TWIN-PULSE LIFE SUPPORTK.H. Yoon1,5, S.W. Choi1,2,5, S.M. Lee1,5, B.G. Min2,3,5. 1InterdisciplinaryProgram in Medical and Biological Engineering Major, Graduate School,Seoul National University, Seoul, 2Department of Biomedical Engineering,College of Medicine, Seoul National University, Seoul, 3Institute of Medicaland Biological Engineering, Medical Research Center Seoul National University, Seoul, 4NewheartBio Co., Ltd., 5Korea Artificial Organ Center,KoreaAim: Many researchers showed the benefits of pulsatile flow, but it is diffi-cult to make pulsatile blood pump satisfying sufficient Energy EquivalentPressure (EEP). Twin-Pulsatile Life Support (T-PLS: Newheartbio. Co. Ltd)is commercially available device for Extracorporeal Life Support (ECLS),and shows good performance for pulsatile blood perfusion. But the motordriving system of T-PLS is limited to pumping speed control that it couldnot regulate the pump pressure as the arterial/venous pressure is fluctua-tion. Methods: Newly designed T-PLS motor control architecture is a PIC-based feedback control, namely the actuator position control for one strokevolume regulation. The influence of inlet pump pressure and outlet pumpto the torque is experimentally measured and the torque/pump pressureequation is induced. The micro controller compensate current loss by torquedisturbance based on the induced equation. Three-phase inverter module isespecially designed using three Hall-effect sensors and a current sensor. Theactuation position is obtained by rotary encoder (Autonics co.) and it usedas output results of reference input. Results: The actuator position con-troller for T-PLS is settled, and the angle position of ratary encoder outputfollows the reference sinusoidal input in 0.68s. The frequency response is3.17 Hz, and it stably follow the reference input to 187.2 beat/sec. Conclu-sion: Newly designed BLDC motor controller shows that it could use asprepump pressure regulator. If the regulating actuator reference input isgenerated in any emergency situation, T-PLS motor controller could followthe input and it could be a good solution for avoid the suction situation.

P 037 REMOTE OPTICAL HEART BEAT MONITOR FROMMECHANICAL VIBRATIONSL. Scalise1, U. Morbiducci1,2, M. De Melis1, M. Grigioni2. 1Dept of Mechan-ics, Università Politecnica delle Marche, Ancona, 2Technology and HealthDept, Istituto Superiore di Sanità, Rome, ItalyMonitoring heart beat and in general cardiac activity is a typical taskrequested in clinical environment. A non contact method that could allowto monitor a subject’s heart beat without any contact with the skin, from adistance, could represent a future tool in a large number of fields, alsooutside the clinics. To do this, we developed a radical new approach, laserDoppler vibrometry, by means of which we measured the velocity and dis-placement of the external surface on several cardiovascular sites. Themethod could be used to monitor a person’s heartbeat from several dis-tances away, without any electrical connections. In particular, we pointed alaser beam (about 1.5 m distance) at a point on the chest wall and anotherlaser beam at a point on the external carotid. ECG and vibratory signalsfrom the chest wall and carotid were simultaneously recorded. To stress thelimits of the VCG signals as quantitative marker of the autonomic activity,heart rate variability (HRV) descriptors (as from time and spectral analy-

sis) were calculated on ECG recordings, and on the newly derived quanti-ties extracted from the vibratory signals both from carotid and chest. HRVindexes obtained from these districts agreed with the rate derived fromECG recordings. Our comparison concludes that the proposed approach issuitable for HRV analysis in both the two investigated sites of measurement.VCG appears promising as non-contact method to monitor the cardiacactivity in subjects under specific conditions. Potential applications of VCGinclude remote monitoring of burns victims who cannot be touched, of incu-bated newborns, of workers subjected to hazardous conditions, and ingeneral when electrodes could not be applied.

P 038 SYNCHRONIZATION OF THE UNDULATION PUMP VEN-TRICULAR ASSIST DEVICE WITH NATURAL HEARTBEATI. Saito1,T. Chinzei1,Y. Abe2,T. Isoyama2, S. Mochizuki2,T. Ono2,A. Kouno2,N. Mitsumune1, N. Taniguchi2, A. Sugino2, W. Shi2, H. Nakagawa1 and K. Imachi2. 1Research Center for Advanced Science and Technology, TheUniversity of Tokyo, 2Graduate School of Medicine, The University ofTokyo, Tokyo, JapanThe undulation pump ventricular assist device (UPVAD) may be driven ina pulsatile flow mode, synchronized with natural heartbeat. The UPVAD isof a volume displacement type which delivers blood by undulation move-ment of a disk inside the pump. The fast response characteristics of thedevice not only can generate a pulsatile flow, but also can adjust the phaseagainst natural heartbeat for better performance. The device is operated inboth co-pulse assist flow and counter pulse assist flow. The preliminary resultsuggested that co-pulse assist flow is preferable than the other in terms offlow amount. This study was supported by the Program for Promotion ofFundamental Studies in Health Sciences of the Pharmaceuticals andMedical Devices Agency (PMDA).

P 039 APPLICATION OF TRADITIONAL AXIAL PUMP DESIGNTHEORY ON VENTRICULAR ASSIST DEVICE DESIGNY. Wang, X. Song, C. Ying. Department of Engineering Physics, TsinghuaUniversity, Beijing, ChinaBackground/Aim: The sizes of implantable heart pumps are far from theapplicable ranges of traditional industrial pump design theories. It is ques-tionable to simply take advantage of those design theories in the heart pumpdesigns. The aim of this study is to investigate how those theories can beapplied in the miniature pump design. Methods: An implantable heartpump, which will work between the left ventricle and the aorta and provide100 mm Hg pressure rise, has been designed and studied in this article. Byusing the traditional pump design theories and procedures, the head coeffi-cients, blade length, blade angels, hub and shroud diameters are determinedin the initial design. This gives the basic geometric information of the heartpump. Computational Fluid Dynamics (CFD) has been used to ensure andoptimize the performance. CFD simulation can help study the 3-D fluidfields, adjust the parameters from the design theories, and finalize the design.Pressure-flow rate (P-Q) curves are calculated and flow vectors and shearstresses are presented. Results: The traditional pump design theories arehelpful to provide the reasonable ranges for some primary geometric para-meters, such as the dimensions and the angels, and to calculate the efficien-cies. CFD simulations show more fluid details to analyze the performanceof the heart pump. The vortices and high shear stress regions can be mini-mized by adjusting the both operational and geometric parameters. Con-clusion: The traditional pump design theories can only be used for the initialdesign of miniature heart pumps. The parameters must be adjusted andfinalized by means of CFD.

P 040 DESIGN AND IMPLEMENTATION OF ACTUATOR HEADOF CARDIOPULMONARY BYPASS PUMP, T-PLSH. Choi1,4,5, H.G. Yoon1,4,5, D.W. Lee1,4,5, K.H. Lee1,4,5, B.G. Min2,3,4,5,6. 1Inter-disciplinary Program in Biomedical Engineering Major, Seoul National Uni-versity, Seoul, 2Department of Biomedical Engineering, College ofMedicine, Seoul National University, Seoul, 3Institute of Medical Engineer-ing, Medical Research Center, Seoul National University, Seoul, 4KoreaArtificial Organ Center, Seoul, 5Cancer Research Center, Seoul NationalUniversity Hospital, 6NewheartBio. Co., Ltd., Dongan-Gu, Anyang-Si,Gyeonggi-Do, KoreaAim: A new pulsatile, portable cardiopulmonary bypass system (T-PLS,NewheartBio, Korea) has been developed and it generates a physiologicpulsatile blood flow without another device. A pulsatile flow is produced byactuator pendulum speed (rpm) periodically. However, there is a concern

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that the previous actuator head causes too much fatigue stress on the bloodsacs (Silicone tubing) of Pump pack. Also, more blood output volume isrequired. Methods: Thus, New designed actuator head was applied to theblood sac and tested. To determine silicone tubing pressure internalsresponse, and structural integrity, simulation was performed by FiniteElement Method. Finally, real teat was done to compare the previous oneand the new one in terms of blood sac life span and blood output volume.Results: Experimental and Simulation results were compared so that theperformance of the new designed actuator head was better than that of theprevious one. Conclusion: the fatigue stress on the blood sac was dramati-cally decreased and blood output volume was reasonably increased by thenew designed actuator head.

P 041 EVALUATION OF HEMODYNAMIC EFFECT OF PRES-SOTHERAPY USING IMPEDANCE CARDIOGRAPHYT. Palko1, M. Szwast1, G. Cybulski1, M. Darowski2, M. Kozarski2, K.J. Palko2,K. Gorczynska2. 1Institute of Precision and Biomedical Engineering,Warsaw University of Technology, Warsaw, 2Institute of Biocybernetics andBiomedical Engineering, Polish Academy of Sciences, Centre of ExcellenceARTOG, Warsaw, PolandBackground/Aim: A pressotherapy based on sequential compression oflower extremities using external pneumatic cuffs is efficient method for non-invasive support in chronic venous and lymphatic disease. The pressother-apy, with pressures below end-diastolic blood pressure values causesincrease lymph and venous flows while pressure wave in the cuffs “moves”in the direction of the heart. The aim of presented study was to assess howthis type of pressotherapy influences cardiac output. Methods: The appara-tus developed in the Institute of Biocybernetics and Biomedical Engineer-ing, Polish Academy of Sciences was used. Changes of stroke volume duringpressotherapy were analysed by impedance cardiographic method. It wastested on 11 healthy volunteers of age 23–26 and one person of age 57. Theexaminations were done at two different pressures in cuffs: lower pressureof 50 mmHg (below diastolic pressure) and higher pressure of 80 mmHg(nearly diastolic pressure). For measurement of impedance signal a specialconstruction of digital reograph (own design) was used. Original computerprogram for data processing was prepared. Results: The results receivedduring this study show that stroke volume increases during pressotherapybut blood arterial pressure and heart rate are stable. Conclusion(s): Thepressotherapy caused increase of the total blood flow proportionally tostroke volume. The work was supported by the Foundation for PolishScience and grant Eureka E! 2939—CAVASCREEN.

Dialysis 2

P 042 DOES A REDUCTION OF ADHESION MOLECULES BYLDL-APHERESIS HAVE A ROLE IN THE TREATMENT OFSUDDEN HEARING LOSS?A. Ramunni1, N. Quaranta2, M.T. Saliani1, R.A. Fallacara2, R. Ria3,G. Ranieri3. 1Section of Nephrology, Department of Internal and PublicMedicine, 2Otolaryngology Clinic “G. Lugli”, Department of Ophtalmologyand Otorhinolaryngology, 3Section of Internal Medicine, Department ofBiomedical Sciences and Human Oncology, University of Bari, ItalyBackground: Sudden hearing loss (SHL) is a highly disabling affliction thatcan severely affect the subject’s social and relational life. Although the eti-ology of the complaint is still debated, it is thought that microcirculationdisturbances conditioned by an endothelial dysfunction may be the mainpathogenetic mechanism. Adhesion molecules favoring interaction betweenthe leukocytes and the endothelial cells are early markers of endothelialdamage. Methods: We describe a case of SHL on the right side that had norecovery of hearing after three days of standard treatment and that under-went a single session of LDL/fibrinogen apheresis, with the Heparin Extra-corporeal LDL Precipitation (HELP) system (BBraun). Results: A hearingtest performed 12 hours after treatment showed recovery on the right, to aPTA of 47 dB HL from a right-sided hearing loss of 70–80 dB HL. Seventy-two hours after the apheresis the patient showed normal right-sided hearing(PTA 23 dB HL) and normal speech discrimination (100% at 50 dB HL). Inthis patient, in addition to reducing LDL cholesterol and fibrinogen (57.6%and 51.4%, respectively), the circulating adhesion molecules (sE-selectin,sVCAM-1 and sICAM-1), previously present in higher than normal con-centrations, were reduced by the treatment (29.5%, 12.6% and 19.7%,respectively). Conclusion: The resolution of hearing loss resulting from one

session of LDL/fibrinogen apheresis together with a significant reduction ofLDL cholesterol, fibrinogen and also of the circulating adhesion moleculessuggest that all these components may have a role in the genesis of the disturbance.

P 043 BRAIN NATRIURETIC PEPTIDE AND DIALYSIS EFFI-CIENCY IN AUTOMATED PERITONEAL DIALYSIS PATIENTSF. Fabbian, F. Malacarne, M. Russo, A. Storari, V. Orlandi, L. Catizone.Renal Unit, St. Anna Hospital, Ferrara, ItalyBackground: It has been established that brain natriuretic peptide (BNP)is a marker of cardiac disease, however data about peritoneal dialysispatients are scarce. Methods: We carried out a cross-sectional study inves-tigating 22 subjects on automated peritoneal dialysis (APD). They were 13males, were aged 60 ± 15 years and have been on renal replacement therapyfor 18 (range 3–108) months. Weight, blood pressure, albumin, calcium,phosphate and their product, degree of anaemia and its treatment, Kt/V,protein catabolic rate and BNP were measured while smoking, diabetes,ischaemic heart, cerebrovascular, peripheral vascular diseases history wasevaluated. Results: In 11 patients BNP was within the normal referencevalue (<100 pg/ml) and in the group suffering of symptomatic coronary ath-erosclerosis was higher than in patients with no cardiac symptoms (953 ±1510 vs 93 ± 76 pg/ml, p = 0.0021). Moreover LnBNP was inversely relatedto Kt/V (r = -0.415, p = 0.05) and phosphorus levels (r = -0.421, p = 0.05)whilst the hormone did not show any relationship with any other parame-ter investigated. Conclusions: Peritoneal dialysis is not a factor influencingBNP plasma levels. In APD patients BNP is associated to cardiac diseasebut it could be also inversely related to dialysis efficiency and phosphoruslevels.

P 044 HEMODIALYSIS PATIENTS: FETUIN-A AND INFLAMMA-TION-NUTRITION STATEM. Manni1, G. Splendiani2, A. Balducci1, M. Morosetti3, D. Mantella2,S. De Angelis2, A. Naticchia2, A. Vega2, M.R. Dessì4, G. Coen2. 1Dept. ofNephrology S. Giovanni Addolorata Hospital; 2“Tor Vergata” University;3G.B. Grassi Hospital, Ostia and 4Dept. of Laboratory Med. “Tor Vergata”University, Rome, ItalyMalnutrition and inflammatory state is common in hemodialysis (HD)patients.

Fetuin-A is a negative acute reactive protein, synthesized in the liver,varying inversely to CRP and a1-acidglycoprotein and it is considered amarker of cardiac risk factor. In HD patients serum levels of Fetuin-A arelower than normal.Aim of the study was to evaluate the relationship betweenFetuin-A and the deranged inflammatory-nutritional status in a populationon HD. 120 patients (77M/43F, age 59.1 ± 13.1 years, HD age 63.5 ± 61.8months) were enrolled for evaluation of serum Fetuin-A, the lipid profile,nutritional and inflammatory markers, Hb concentration, BMI and Kt/V.

Serum Fetuin-A levels were lower than normal (0.328 ± 0.11 g/L; vn 0,519± 0.15 g/L) and were correlated to prealbumin (p < 0.0001), triglycerides (p < 0.001), serum cholesterol (p < 0.05), non-HDL cholesterol (p < 0.01),BMI (p < 0.05) and Hb (p < 0.05).

Multiregression analysis with Fetuin-A as dependent variable selected thefollowing variables: prealbumin (p < 0.0001), KT/V (p < 0.02) and Hb (p <0.04). By dividing the patients in tertiles of serum Fetuin-A levels, CRP wassignificantly higher in the lower compared to the second and third tertiles.Therefore, Fetuin-A, prealbumin and CRP were strongly associatedmarkers, showing a strict link between Fetuin-A and inflammatory andnutritional markers. In conclusion, Fetuin-A in hemodialysis patients ismainly associated with inflammatory-nutritional parameters, which areknown to favor atherogenesis and anemia. Increased cardiac mortality inHD patients with low levels of Fetuin-A is probably a direct consequenceof malnutrition, inflammation and anemia (MIA syndrome), the severity ofwhich is highlighted by the levels of Fetuin-A.

P 045 PREVALENCE OF HEPATITIS C AND HEPATITIS B VIRUSINFECTION IN DIALYSIS PATIENTSP. Dzekova1, A. Sikole1, A. Slavkovska2, Lj. Simjanovska2, G. Efremov2,I. Nikolov1, M. Polenakovic1. 1Department of nephrology, Clinical Centre,Skopje, R. Macedonia, 2Research Center of Genetic Engineering and Biotechnology, Macedonian Academy of Science and Arts, Skopje,R. MacedoniaBackground: hemodialysis patients are at particularly high risk for hepati-tis C (HCV) and hepatitis B (HBV) virus infection because of the exposure

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to blood products, infected patients and contaminated equipment. The highprevalence of HCV infection in dialysis patients is of great concern becausethese patients have a higher mortality than HCV negative patients. Aim: toevaluate the prevalence of HCV and HBV infection among patients onhemodialysis at our dialysis unit, till April, year 2005. Patients and Methods:our study was made on 178 patients (113 men and 65 women, mean age 54.8years and mean time on dialysis 86 months). The presence of HCV anti-bodies and of HBs Ag was determined by ELISA III. The presence orabsence of the viral particles in serum in HCV antibody positive patientswas assessed by reverse-transcriptase PCR (HCV RT-PCR). Typing of HCVRNA positive patients was performed using Allel Specific Oligonucleotide(ASO) Hybridization. Results: from 178 patients, 114 (64%) were anti-HCVpositive and 64 (36%) were anti-HCV negative. Anti-HCV positivity wassignificantly associated with dialysis duration (p < 0.00), number of trans-fused blood products (p < 0.03), levels of serum aminotransferases (p <0.00), and levels of bilirubin (p < 0.01), but not with the age of the patients.Among 114 anti-HCV positive patients, 55 (48%) patients were HCV RNApositive and 59 (52%) patients were HCV RNA negative, underwent spon-taneous viral clearance. Almost all HCV RNA positive patients were geno-type 1 (96.4%), only 2 patients were genotype 4 (3.3%). HBs Ag positivitywas found at 23 (12.9%) patients and it was significantly associated onlywith serum levels of bilirubin (p < 0.01). Co infection with HCV and HBVwas present at 2 (1.12%) patients. Conclusion: the prevalence of HBV infec-tion is 12.9% in our dialysis unit, although the isolation of HBsAg positivepatients on separate machines and preventive vaccination. There is highprevalence of HCV antibodies positive patients (64%) with statistically sig-nificant association with dialysis duration, number of blood products trans-fusions, levels of serum aminotransferases and bilirubin. The absence ofHCV RNA at 52% of anti-HCV positive patients, indicates spontaneousclearance of the virus, suggesting that both viral and host genetic factorshave impact on the outcome of HCV infection.

P 046 INTIMAL-MEDIA THICKNESS IS RELATED TO CORO-NARY ARTERIES DAMAGE IN HEMODIALYSIS PATIENTSF. Fabbian1, G. Cacici2, L. Franceschini2, M.M. Conte3, C. Vassanelli2,L. Catizone1, A. Lupo3. 1Renal Unit, St. Anna Hospital, Ferrara, 2Depart-ment of Cardiology, OCM, Verona, 3Department of Nephrology, OCM,Verona, ItalyBackground: Data relating ultrasonography (US) of carotid artery (CA) tocardiovascular events in hemodialysis patients (HDP) are scarce. Methods:We carried out a cross-sectional study relating US of CAs to coronaryangiography in 33 HDP (age 55 ± 12 years, 22 male, 7 diabetic), who havebeen on renal replacement therapy (RRT) for 41 ± 48 months (range 2–192).21 underwent coronary angiography in order to complete clinical evalua-tion for kidney transplantation waiting list, whilst 12 because of ischemicheart disease (IHD). Intima-media thickness (IMT) of CAs and presenceof plaques were measured with US and were related to the degree of coro-nary stenosis and to cardiovascular risk factors. HDP were divided into twogroups depending on mean IMT (group 1 IMT = <0.9 mm, n = 18; group 2IMT >0.9 mm, n = 15). Results: Group 2 was older (60 ± 8 vs 50 ± 12 year,p = 0.01), had higher frequency of IHD (53 vs 16%, p = 0.02) and had higherprevalence of HDP with coronary artery stenosis = >75% in right (60 vs22%, p = 0.02), left anterior descending (46 vs 16%, p = 0.06) and left cir-cumflex coronary (60 vs 11%, p = 0.05) than group 1. The differences in themean percentage of stenosis of the three major coronary arteries were notstatistically different in the two groups. None of the HDP had carotid steno-sis greater than 50%. IMT sensibility and specificity in detecting the pres-ence of hemodinamically significant coronary stenosis were 64 and 68%respectively. Conclusions: Measurement of IMT as a simple, non-invasiveexamination could be a helpful tool in the screening of HDP who need tounderwent coronary angiography.

P 047 CARDIOVASCULAR STATE IN A PATIENT WITH PRIMARYAMYLOIDOSIS, ROLE OF BRAIN NATRIURETIC PEPTIDEF. Fabbian1, V. Orlandi1, S. Sergio2, N. Stabellini1, C. Molino1, M. Russo1,L. Catizone1. 1Renal Unit, St. Anna Hospital, 2Internal Medicine, St. AnnaHospital, Ferrara, ItalyBackground: Cardiac involvement occurs in up to 50% of patients withprimary amyloidosis and is associated with a very poor prognosis. Brainnatriuretic peptide (BNP) has been recently proposed as a guide for thetreatment of heart failure patients. Although it is well known that in uremiathe prevalence of heart failure is high, there are a few data about cardio-

vascular monitoring of patients with AL amyloidosis on renal replacementtherapy. Case: A 64 year old Caucasian man was admitted because ofnephrotic syndrome in July 2003. Renal diagnosis was primary amyloidosis.Melphaln and prednisolone were given but renal function worsened and inApril 2004 standard bicarbonate hemodialysis was started. In March 2004thalidomide was added to his therapy. During the follow-up ejection frac-tion was stable and was 65%, on the contrary E/A ratio gradually increasedand overtook 1. BNP plasma levels were increased and the values recordedduring the follow-up were 2505 pg/ml in October 2003 (normal referencevalues <100), 1827 in April 2004, 4006 in June 2004, >5000 in September2004, 3750 in January 2005 and 1920 in April 2005. The decrease in BNPconcentration was related to the prescription of acetate free biofiltration(AFB) which was started in February 2005 and cardiovascular stateimproved. Conclusion: It has been reported a powerful prognostic deter-minant in AL amyloidosis of BNP whose expression is increased in ven-tricular myocytes of patients with cardiac involvement. BNP levels appearto be very useful in order to monitor cardiovascular status of patients withamyloidosis. AFB could have a role in improving cardiovascular state inthese patients.

P 048 DIAGNOSIS AND TREATMENT OF RENAL OSTEODYS-TROPHY IN R. MACEDONIAG. Spasovski1, S. Gelev1, V. Zdravkovska2, V. Tomanovski3, L. Trpenovski4,K. Ivanovski5, T. Bajraktarova6, P. Janakievska7, M. Damjanovski8,J. Neskovski9, E. Karceva-Sarajlia10, T. Petrovska11, K. Filkovska12,S. Matovic13, V. Luseva14, D. Jordanovski15, M. Zafirovska16. 1Dept. ofNephrology, Clinical Center Skopje, HD Units: Zelezara2, Struga3, MilitaryHospital4, Kumanovo5, Stip6, Bitola7, Prilep8, Gostivar9, Strumica10,Delcevo11, Kavadarci12, Tetovo13, Gevgelija14, Veles15, K Palanka16

Aim: Our study reports the diagnosis and treatment of ROD in our country.Methods: All 18 HD Centers were invited to fill in a questionnaire. 16Centers replied on this ROD survey including the data from 588 pts. Thefirst part of the questionnaire was related to the clinical data while secondfocused on the last determination of serum biochemistry: calcium (Ca),phosphate (P), parathyroid hormone (PTH) and osteocalcin (OC). Finally,the data on current therapeutical practice for dialysate Ca concentration,phosphate binders and vit. D and parathyroidectomy (PTx) were collected.Results: The provided information on 588 pts. represents 57.3% of ourhemodialysis population. The serum Ca concentration between 2.1 and 2.4mM was found in 40% of patients, <2.1 mM in 19.9% and >2.4 mM in 40.1%of the patients. An ideal phosphate control <1.8 mM was achieved in 67%and CaxP product <4.4 was calculated in 71.1% of the patients. For PTH,the ideal was considered to be between 150 and 250 pg/ml in 13.6% ofpatients. A relatively small proportion had an interval between 250 and 450 pg/ml, i.e. 12.5%. PTH above 450 pg/ml considered as hyperparathyroidbone disease was found in 31.1% of the patients, but the largest part ofpatients with PTH <150 pg/ml considered for an adynamic bone disease(ABD) was calculated in 42.8% of the patients. This condition was also con-firmed with findings of OC <23 ng/ml in 63.6% of the study population. PTxwas performed in only 7% of patients and dialysate Ca concentration of1.25 was used in only 6.1% of the population. Calcium carbonate was usedin 95.6% of patients, with a dose between 0.5 and 3 gr/day in most of thepatients (72.1%). Vit. D (1–2 mg/week) was prescribed in almost half of thepatients (47.4%). Conclusion: This analysis gives useful information for the existing gap between diagnosis and treatment of ROD in our country.The use of high (1.75 mM) dialysate Ca concentration, calcium carbonateand vit. D treatment might be associated with development of ABD.

P 049 ANTIOXIDANT THERAPY BY ORAL VITAMIN E ANDVITAMIN E-COATED DIALYZER IN CAPD AND HEMODIA-LYZED PATIENTSM. Mydlík1, K. Derzsiová2, O. Rácz1, A. Sipulová1, E. Lovásová1. 1MedicalFaculty, University of P.J. Safárik, Kosice, 2University Hospital of L. Pasteur,Kosice, Slovak RepublicAim of the study was to investigate the influence of oral vitamin E (400mg/day) in CAPD patients and vitamin E-coated dialyzer in hemodialyzed(HD) patients on antioxidant defense parameters. Patients and Methods: In14 CAPD and 14 HD patients erythrocyte (ER) superoxide dismutase(SOD), glutathion peroxidase (GPX), catalase (CAT), (spectrophotometricassays from RANDOX), plasma (P) malondialdehyde (MDA) and P or ERvitamin E (VE), (spectrofluorometric assays) were investigated at the begin-ning and at the end of the CAPD (after 6-week of oral treatment with VE

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400 mg/day) and HD study (after 3-month using a modified vitamin E-coated dialyzer, Terumo CL-E15NL). The same parameters were investi-gated 6 resp. 10 weeks (10W) after the end of the studies. Results:

Parameter CAPD (week) HD (month)0 6 0 3 10W

SOD(U/gHb) 925 ± 190 915 ± 190 818 ± 153 880 ± 131** 879 ± 125GPX(U/gHb) 38 ± 14 35 ± 11 49 ± 13 52 ± 14 48 ± 16CAT(U/gHb) 4.5 ± 1.2 4.5 ± 1.5 4.9 ± 0.8 5.5 ± 1.2 5.4 ± 1.3MDA(mmol/L) 2.6 ± 0.5 2.3 ± 0.4* 2.9 ± 0.4 2.3 ± 0.4** 2.9 ± 0.3aP-VE(mmol/L) 33.6 ± 9 49.3 ± 15** 25.9 ± 3 33.6 ± 4** 28.6 ± 4aER-VE(mmol/L) — — 6.7 ± 0.8 7.4 ± 0.7* 6.9 ± 0.7b

Normal Range: SOD: 990 ± 85, GPX: 45 ± 10, CAT: 4.8 ± 0.6, MDA: 2.12 ±0.4, P-VE: 23.5 ± 5, ER-VE: 7.7 ± 1.1, *p < 0.05, **p < 0.01-versus at thebeginning of the study, bp < 0.05, ap < 0.01-versus at the end of the study.Conclusions: 1. Six-week treatment with oral VE in CAPD patients and 3-month using a vitamin E-coated dialyzer in HD patients led to the signifi-cant decrease of plasma MDA and to the significant increase of P-VE andER-VE in HD patients. 2. No significant changes of ER antioxidantenzymes—SOD, GPX and CAT were found during studies. 3. Ten-weekinterruption of the use of vitamin E-coated dialyzer led to the increase ofP-MDA and to the decrease of P and ER-VE near to the values at thebeginning of the study. 4. Our study confirms the beneficial effect of oraladministration of VE (400 mg/day) and dialysis membrane with VE againstoxidative stress in CAPD and HD patients.

P 050 THE EFFECT OF CHRONIC INFLAMMATION ON THENUTRITIVE STATUS OF PATIENTS TREATED BY CHRONICHEMODIALYSISA. Sikole, P. Dzekova, G. Severova, N. Stojcev, V. Amitov, R. Grozdanovski.Department of Nephrology, Clinical Centre, Medical Faculty, University ofSkopje, R. MacedoniaPatients with end-stage renal disease treated by chronic hemodialysis expe-rience poorer quality of life and higher rate of morbidity and mortality com-pared to the general population. A number of studies indicated thatmalnutrition, present in 18–75% of the dialysis population, significantly cor-related with the rate of morbidity and mortality. They also suggested thatmalnutrition in patients on dialysis was not solely caused by the low proteinand calorie intake, but could also result from the state of chronic inflam-mation. The aim of the study was to assess the effect of chronic inflamma-tion on the nutritive status in a cohort of patients treated with chronicintermittent hemodialysis at our dialysis unit. We assessed 154 patients: 61female and 93 male. Their mean age was 54.7 ± 12.8 years, with mean dial-ysis duration of 84 months (range 7–288 months). They received standardbicarbonate hemodialysis 12 hours per week, with a low-flux polysulfonemembrane of 1.3m2. Single pool KT/V for the group averaged 1.2 ± 0.2, andthe mean dietary protein intake was 1.07 ± 0.1 g/kg/day, as measured by theprotein catabolic rate. A number of laboratory parameters were routinelymonitored and among them were CRP and serum albumin levels. The nutri-tive status was assessed through the anthropometrical parameters: bodymass index (BMI), triceps skin fold thickness (TSF), mid-arm muscle cir-cumference (MAMC). The biochemical and anthropometric parametersindicative for the nutritive status of the patients revealed low normal reference values for the whole group. There was a negative correlationbetween CRP and serum albumin concentration in women and men. Wefound no correlation between CRP and MAMC in both women and men,no correlation between CRP and TSF, and CRP and BMI. So, no influenceof the state of chronic inflammation on the anthropometric parameters ofthe nutritive status was found. However, there was a negative effect ofchronic inflammation on the serum albumin levels i.e. on the visceral proteinmass. Our group of patients was relatively well nourished (PCR = 1.07 ±0.1 g/kg/day). It is possible that adequate nutrition could overcome the negative effect of chronic inflammation on the nutritive status.

P 051 THE ROLE OF AN INTERNATIONAL APHERESIS REG-ISTRY FOR THE ESTABLISHMENT OF APHERESIS THERAPYB.G. Stegmayr1, L. Guillevin2, J.M. Korach3, G. Rock4, R. Norda5,W. Ramlow6. Chairman, WAA Registry Committee1, President WAA2, rep-resentatives for the development of national registries in France3, Canada4,Sweden5, and for WAA6

Since apheresis may be performed in many different ways for many differ-ent indications world wide the World Apheresis Association (WAA)

decided to start a registry. The aim of the registry is to improve knowledgeabout indications, techniques and adverse events to optimize informationand therapy of the patients. In addition the knowledge will be helpful forindustry to further develop devices and bring them into market. In Decem-ber 2002 WAA launched such world-wide apheresis registry to gain insightinto the extent of treatment, adverse events, and to facilitate contacts amongcentres when treatment indications are rare and experience limited.Apheresis procedures to collect stem cells and other blood products,intended for clinical application, should also be able to enter. Since thenseveral centres and countries have entered the registration procedure. Eachcentre at the end of the year gets a file of their own data for own statistics.We now cordially invite also other centres to join the registry. Please, alsoinform colleagues at other centres in your country to join. E-mail andaddress lists of colleagues in your country who have not registered will bewelcomed. The site is at: http://www.iml.umu.se/medicin/ Go to WorldApheresis Registry; Present version: Login code to test the Registry is:al61tms (AL61TMS). New version: Login codes to test the Registry is:testversion and: v9pzYM (don’t change user code). Then apply for a spe-cific login code for your centre. We welcome you to this registry for yourinput of data. You will not be charged any registration fee. At the momentthe site is also under development to facilitate registrations and feed back.In the future the registry is planned to include information about indica-tions, techniques and various interactive approaches.

P 052 WORLD APHERESIS REGISTRY- REPORT OF 2004 DATAB. Stegmayr1, J. Ptak2, B. Wikström3, G. Berlin4, C.G. Axelsson5,A. Griskevicius6, P. Centoni7, G. Liumbruno7, J. Audzijoniene6, K. Mokvist3,B. Nilsson Sojka8. Departments of Nephrology1,3 and Blood Bank orApheresis Centers2,4,5,6,7,8 in Umea1,8, Uppsala3, Linkoping4, Orebro5,Sweden, Ostrava2, Czech Republic, Vilnius6, Lithuania, and Livorno7, ItalyCentres from 12 countries have applied for a login code to the WAA aphere-sis registry. Of these 9 centres from 4 countries have been actively enteringdata during 2004. Registered are at the moment a total of 347 patients (55%women, mean age 54 y, and 45% men, mean age 52 y). Main indications wereneurological (33%), vasculitis (9%), and lipid apheresis (8%). In 92% of thepatients therapeutic apheresis was performed while in 8% retrieval of com-ponents was the reason. A total of 1808 procedures were registered. Morethan 88% of the patients had acute indications. Access was mainly byperipheral vessels (65%), central dialysis catheter through jugular route(11%) or subclavia (9.4%) while femoral vein and AV fistula were used in4.3 versus 0.5% of occasions. Anticoagulation was performed by ACD(80.5%), CPD citrate (2.5%), ACD and heparin (7%), ACD and LMWheparin (4%) and only heparin (5.8%). Replacement fluids for therapeuticapheresis removing plasma was mainly by albumin (85%) while plasma(22%) and cryoprecipitate poor plasma (5%) was used to less extent.Adverse events (AE) were registered in 6% of procedures. Distribution wasfor mild AE (1.4%), moderate (3.4%) and severe (0.6%). In 21 treatmentsthere were 2 AEs while in 2 patients there were 3 AEs. Most frequent AEswere hypotension (35%), tingling around the mouth (24%), chill and fever(5.5%) and urticaria (5.5%). There were significant differences between thecentres. The incidence of hypotension varied between 0.36–3.23% betweencentres. There was no significant difference in severe AEs between thecentres. Main procedure used was centrifugation technique for conventionalplasma exchange by centrifugation or filtration, while other modes wereleukapheresis, erythrapheresis, platelet apheresis, LDL-apheresis, photo-pheresis and adsorption. Conclusion: Data from the registry show thatcentres have various approaches to apheresis. One can learn from eachothers experience to reduce side effects and improve efficacy.

Dialysis 3

P 053 IMMUNOLOGICAL BASIS OF APPLICATION OFHEMOSORPTION, ULTRAFILTRATION AND DIRECT BLOODOXYGENATING IN PSORIASIS TREATMENTV.N. Korol. National Medical University, Kiev, UkraineBackground/Aim: to carry out immunological appraisal of the effectivenessof application of the combined method of extracorporeal therapy includingsimultaneous realization of hemosorption, ultrafiltration and direct bloodoxygenating (HS, UF, Ox) in the treatment of complicated and spread formsof psoriasis. Methods: while carrying out the methods HS, UF and Ox bloodoxygenating was done through oxygenator under pressure of 50,5–80,9 kPa.Oxygenated blood came to the massexchange element with hemosorpent

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where sorption was carried out. Simultaneously ultrafiltration with remov-ing 2–6 l of ultrafiltrate and adequate introduction of substituting solutionswas done. The speed of hemoperfusion was 64–96 ml/min, the volume of circulating blood is 2–3 VCB.

P 054 DETOXIFYING ACTION OF CERULOPLASMIN IN ACUTERENAL FAILUREM.V. Osikov, L.V. Krivohizhina, E.V. Makarov. Chelyabinsk State MedicalAcademy, Chelyabinsk, RussiaBackground/Aim: Accumulation of toxic substances in the organism iscrucial in pathogenesis of renal failure. Ceruloplasmin (CP), a copper-con-taining glycoprotein of human blood plasma, is a multyfunctional protein,bearing abiblity to stabilize cell membranes, inhibit lipoperoxidation, stim-ulate haemopoesis. The goal of this research was to investigate influence ofCP on endogenous intoxication in acute renal failure (ARF). Methods:Experiments were carried on 40 white male rats. ARF was induced by sub-cutaneous injection of mercury chloride (8 mg/kg). ARF was verified withcreatinine and urea levels measurements. CP (NPO “Immunopreparat”,Ufa, Russia) was injected i.p. in summary dose 20 and 60 mg/kg (20 mg*3times). Rats were sacrificed on 5th day. Endogenous intoxication was eval-uated by level of “low and middle weight substances” (LMWS) and Lowry-positive substances (LPS), in plasma and erythrocytes, after treatment ofsamples with 15% trichloroacetic acid and centrifugation. Results: Singleinjection of CP (20 mg/kg) did not alter endogenous intoxication (p > 0,05)in ARF. Probably this dose is too low. Three-times injection of CP lead tosignificant shanges: concentration of LMWS in plasma decreased (p < 0,05),level of LPS left unchanged. Concentration of LMWS and LPS in erythro-cytes, by contrast with plasma, was elevated significantly (p < 0,05). Con-clusions: Ceruloplasmin in 60 mg/kg dose shows detoxifying action in acuterenal failure, while 20 mg/kg dose in insufficient. This effect is mediated viadecrease of toxic substances in plasma, and their redistribution on surfacesof erythrocytes. Probably, this is due to stabilisation of erythrocyte cell mem-branes by antioxidant action of ceruloplasmin.

P 055 SIGNIFICATIVE REDUCTION OF “POST-PUMP SYN-DROME” WITH CONTINUOUS INTRA-OPERATIVE VENO-VENOUS HEMOFILTRATION (CVVH) WITH HIGH VOLUMES OFEXCHANGE 35 ML H-1 KG-1 VERSUS 20 ML H-1 KG-1 DURINGCARDIOPULMONARY BY-PASS (CPB)R. Luciani*, C. Simon°, G. Punzo*, P. Menè*. *Nephrology Unit Sant’Andrea Hospital Rome, °Cardiac Surgery Unit Sant’Andrea HospitalRome, ItalyBackground: Cardiac surgery needs the use of CPB: this practice is con-nected with a clinical condition called “Post Pump syndrome”. It dependson several factors: width of extracorporeal circuit, fast modifications of bodytemperature, surgery trauma, ischemia/riperfusion. Clinically it is charac-terized by reduction of pulmonary compliance with increased peri-alveolarfluids similar to adult distress respiratory syndrome (ARDS), by extensionof mechanical ventilation time and Intensive Care Unit length of stay. TheAim of the Study is to demonstrate the power to lower post CPB systemicinflammatory response with “post-pump syndrome”, using an intraopera-tive CPB circuit connected with a monitor for CVVH with different doseof ultrafiltration (20 ml h-1 kg-1), (35 ml h-1 kg-1). Methods: We examined20 patients who underwent isolated coronary artery bypass grafting(CABG): they were randomly assigned into 2 groups: group 1 CABG withCVVH 35 ml h-1 kg-1 substitution liquid rate (n = 10; 6M-4F; mean age 58 ± 8), group 2 CABG with CVVH 20 ml h-1 kg-1 substitution liquid rate(n = 10; 5M-5F; mean age 65 ± 7) CPB management: Dideco Terumo coated,oxygenator Avant D903-Capiox RX 25 coated with integrated cardiotomy,Stockert SIIImonitor; CVVH with Prisma Hospal monitor, AN69 M100 preset filter, no heparin, blood flow = 150 ml/min, ultrafiltration rate 500 ml/h.Connection between the circuits was achieved by joining arterial blood line(CVVH) with venous blood line (CPB), and venous blood line (CVVH)with cardiotomy suction reservoir. We measured the time (hours) neededto remove mechanical ventilation, to reach PaO2/PAO2 > 0,36 and ICUlength of stay. Results: Mechanical ventilation time: Group 1: 4,8 h ± 0,6 h,Group 2: 7,2 ± 0,3 h p < 0,01. PaO2/PAO2 > 0,36: Group 1: 1,8 ± 0,2 h, Group2: 5,2 ± 0,8 h p < 0,01. ICU h: Group 1: 22,7 ± 9,5 h, Group 2: 51,9 ± 10 h p <0,05. Conclusions: Our study demonstrates that an intraoperative CVVHwith high volume of exchange (35 ml h-1 kg-1) is able to reduce mechani-cal ventilation time and ICU length of stay, with a significative improvementof arterial/alveolar exchange.

P 056 DISTRIBUTION OF THE TRANSMEMBRANE PRESSUREALONG THE MEMBRANE SYSTEM AS A CRUCIAL FACTOR FOR EFFICIENCY OF THE MEMBRANE BLOOD OR PLASMATREATMENTA. Ciechanowska1, J.M. Wojcicki1, J. Hartmann2, S. Sabalinska1,D. Falkenhagen2. 1Institute of Biocybernetics and Biomedical EngineeringPAS, Warsaw, Poland, 2Center of Biomedical Technology, Donau University,Krems, AustriaIntroduction: An automatic change of direction of the fluid transportthrough the membrane, along the membrane system become a new methodfor efficient blood/plasma treatment. In the first available systemsblood/plasma flows through capillaries of a single module. Pump in thesecond circuit, outside the membrane, generates a high flow rate, whichintroduces a pressure gradient along the capillaries inducing filtration alongthe first part of the filter and backfiltration along the second part. Anotherpossible realization of such a membrane system refers to utilization of twodifferent types of membrane—plasma separator and plasma fractionation.In both realizations one of the most important factors deciding about suc-cessful performance of the system, is position of the turning point of thetransmembrane pressure (“0” point). Aim: The main objective is to assesinfluence of the fluid viscosity and flow rates in the primary and the sec-ondary circuits on “0” point position along the system during the in-vitrostudy. Results: Experiments were carried out for fixed overall resistance ofthe system (combination of the geometrical dimensions of filters, connec-tors and tubings). Obtained results indicated that the placement of the “0”point is most sensitive to viscosity changes. For example, 2.4 times increaseof the fluid viscosity in the first circuit in comparison with the second oneled to shift of the “0” point toward system outlet by 9 cm i.e. by 20% of thetotal length of the membrane system (TM). Influence of the flow rates hasbeen found to be much lower. Twofold decrease of the flow rate in theprimary circuit led to shift of the “0” point by 1.2 cm (2.6% of TM) and five-fold increase of the flow rate in the secondary circuit—by 2.5 cm (5.5% ofTM). Conclusion: The proper design of the membrane system operatingbased on the automatic change of direction of the fluid transport throughthe membrane, is crucial in terms of the system efficiency. Proper design,especially of the two stages membrane system, should include compensa-tion of the possible changes of the viscosity for example by adjustable geo-metrical dimensions of the system.

P 057 INFLAMMATION AND VASCULAR ACCESS: FAV vs CVC vsPTFEL. Colì, G. Cianciolo, G. Donati, C. Raimondi, D. Mezzopane, E. Persici,E. Tampieri, M.L. Cappuccilli, M. Flachi, S. Stefoni. Nephrology, Dialysis andRenal Transplantation Unit, S. Orsola University Hospital, Bologna, ItalyAim: several studies in ESRD patients have shown that CRP is outcomepredictor and is associated with cardiovascular death. In ESRD patientsamong the causes of inflammation also the vascular access is a possibletrigger. Aim of the study was to evaluate if the different vascular access(native fistula, PTFE, permanent catheter) influence the level of inflamma-tion and, as a consequence of repeated activation, the markers of cellularsenescence and apoptosis in mononuclear cells on ESRD patients. Methods:32 patients with native A-V fistula (Group A) n°10 patients with PTFE graft(Group B) n°28 patients with a permanent catheter (Group C) wereselected for the study. The 3 groups were hom*ogeneous in terms of age, sex,HD schedule, indexes of extracorporeal clearance, comorbidities,. Toexclude the effect of the membrane on the inflammation indexes we use inall patients a PS membrane with different permeability indexes: FX8 in stan-dard HD (low-flux), FX80 in HDF session (high-flux) maintaining the samekind of treatment. The checking session was performed after 2 sessions withthe PS membrane. The parameters evaluated were: PCR, fibrinogen, com-plement, albumin, IL 6, IL 10, IL 4, IL 5, CD 14, CD 32, CD 95. Results:Both HD patients with PTFE graft or with a permanent catheter showedhigher levels of CRP (Group A 0.38 ± 00.04, Group B 1.01 ± 0.04, Group C0.88 ± 0.03, p = 0.02, 0.04) and a higher intradialytic increase of IL6 levels(Group A 74 ± 11%, Group B 310 ± 28, Group C238 ± 25, p = 0.02, 0.01) ifcompared with those founded in patients with native A-V fistula. We did’ntfind any significative difference on the albumin levels among the 3 groups.Conclusions: vascular access represents an underestimated source of inflam-mation in HD patients. Even if the vascular access reflects the clinical con-ditions of the patients, it could, per se influence, by the inflammation process,the clinical outcome of ESRD patients.

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P 058 ENHANCED MEMBRANE CLEANING PROCESS APPLIEDHEMODIALYSIS DIALYZER REUSE SYSTEM USING ULTRA-SONIC WAVESS.M. Lee1,5, S.W. Choi1,2,5, K.H. Yoon1,5, B.G. Min3,4,5. 1Interdisciplinary Pro-grams in Biomedical Engineering, College of Engineering, Seoul NationalUniversity, 2Department of Biomedical Engineering, Seoul National Uni-versity Hospital, 3Department of Biomedical Engineering,College of Med-icine, Seoul National University, 4Institute of Medical and BiologicalEngineering, Medical Research Center, Seoul National University, 5KoreaArtificial Organ Center, KoreaAim: Several advantage of dialyzer reuse has been reported. In presentreusing process, however, the water containing endotoxin is used to diluteconcentrated disinfectant solution or improper mixing and dilution of dis-infectant which causes risk of pyrogenic. Ultrasonic cleaning technique isone of proper manner for membrane wash out process. Therefore, we inves-tigated the cleaning effect of ultrasonic for dialyzer of hemodialysis.Methods: Four used dialyzer was immersed in the bath filled with 6L water,ultrasonic of 50 kHz, 132 kHz and 1 MHz was irradiated respectively and onebath was used for comparison. All ultrasonic power was adjusted at 600 Wso the baths have 1 W/cm3 power and pure-water (type3) was flowedthrough membrane for 30minutes. After this experiment is ended, volumeof ultrafiltration (UF) under 120 mm Hg at blood inlet condition was mea-sured for 100 sec. Results: 132 kHz frequency of ultrasonic waves was themost effective among the others. Conclusion: The cleaning effect using ultra-sonic waves varies with its frequency. We found that 132 kHz was properfrequency to enhance dialyzer cleaning process. We confirmed membranewas cleaned more than 80% according to UF volume measurement.

P 059 EFFICACY AND SAFETY OF LOW MOLECULAR HEPARIN (ENOXAPARIN) COMPARED WITH UNFRACTION-ATED HEPARIN IN HEMODIALYSISS. Gelev, K. Zafirovska, Gj. Selim, G. Spasovski, R. Grozdanovski.Department of Nephrology, Clinical Center, Skopje, R. MacedoniaBackground: Although standard systemic heparinization for hemodialysisis relatively safe and effective, long-term unfractionated heparin use is asso-ciated with bleeding and metabolic side effects. Low molecular weightheparin (enoxaparin sodium) is considered as an effective, safe and conve-nient alternative to conventional heparin anticoagulation in hemodialysispatients. Aim: The aim of this present study is to compare the safetyas wellas the therapeutical and clinical effects of enoxaparin with unfractionatedheparin in our hemodialysis patients. Materials and Methods: In an openlabel, randomized, parallel group study, we treated 26 patients with enoxa-parin sodium and 28 patients with unfractionated heparin during hemodial-ysis sessions (12 weeks/36 hemodialyses) to control intrahemodialysisanticoagulation. Enoxaparin was given as a single bolus dose of 2000 or 4000units, and heparin was given as an initial dose of 1250 to 4000 units followedby 625–1000 units per hour. Anticoagulation was monitored by visualinspection of the dialysers and lines every 30–60 min. Results: There wereno significant differences in the assessment of adverse events (grades 0–3)including local bleeding (0,009 vs 0,011), local allergic reactions (0,001 vs0,005), presence of local hematoma (0,012 vs 0,003), and pain at the punc-ture sites (0,854 vs 0,916), between the groups. No changes in serum lipidsand platelet number were observed during the study with either anticoag-ulant. Also, there were no significant differences between the groups in theassessment of efficacy parameters (grades 0–3) including frequency anddegree of fibrin/clots formation in both, dialysers (0,993 vs 1,066) and bloodlines (0,356 vs 0,281), measurement of compression time needed to stopbleeding at the dialysis puncture sites (0,785 vs 0,756) and presence of hem-orrhagic events between dialyses (0,001 vs 0,024). But, this equivalent effi-cacy was accompanied by a significantly lower (p < 0,05) dose of enoxaparin(3749,77 IU vs 4496,04 IU). Conclusions: The results from this study suggestthat a significantly lower single bolus dose of enoxaparin sodium used as ananticoagulant during hemodialysis is an effective, safe and very convenientalternative to sodium heparin.

P 060 BLOOD RHEOLOGICAL CHARACTERIZATION BY CREEPTESTS TO OPTIMIZE EXTRACORPOREAL BLOOD TREATMENTDEVICES: PRELIMINARY INVESTIGATIOND. Gabriele1, P. Fata1, G. Catapano1, B. de Cindio1, R. Bonofiglio2. 1Univ ofCalabria, Rende, 2Annunziata Hospital, Cosenza, ItalyAim: Diseases treated by EC detoxification processes often alter the rheo-logical properties of patient’s blood. Nonetheless, devices are generally

designed assuming that blood is Newtonian or has viscometric properties ofthe “standard” man. Blood viscosity has long been correlated to its struc-ture. However, blood is a complex fluid and viscometry accounts only forits “liquid” behavior. New rheological techniques account also for the fluid“solid-like” behavior. Fluid deformation measurements under constantstress (creep) characterize well weakly structured fluids as blood. In thiswork, we report on a preliminary investigation to validate creep tests forblood rheological characterization. Methods: Blood and serum from healthyand diseased persons were subjected to creep tests on a RheometricsDSR200 rheometer with parallel plates (f = 40 mm). Tests were performedat 0.09 Pa stress, 37°C, and constant gap. The low stress value preventedblood damages. The deformation-to-stress ratio (i.e., compliance) was mea-sured vs. time. Viscosity was estimated, for validation purposes, as the reci-procal slope of the curve at steady state. Results and Conclusion: Testsperformed on healthy blood yielded viscosity differing for sex and hemat-ocrit in agreement with literature data at same shear rate. No significant dif-ferences were found for serum. In addition, creep tests yielded quantitativeinformation on blood elasticity. Preliminary tests on diseased patient’sblood yielded rheological characteristics that could be correlated to thealtered blood structure caused by the disease. Work performed with a grantfrom MIUR-PRIN 2004 research project.

P 061 THE EXPERIMENTAL STUDY OF DIAYZER REPROCESS-ING WITH PULSATILE FLOWJ.H. Jeong1,4,5, K.S. Lee1,4,5, C.H. Mun1,4,5, J.H. Kim1,4,5, B.G. Min2,3,4,5. 1Inter-disciplinary Program in Biomedical Engineering Major, Seoul National Uni-versity, 2Department of Biomedical Engineering, College of Medicine, SeoulNational University, 3Institute of Medical Engineering, Medical ResearchCenter, Seoul National University, Seoul, 4Korea Artificial Organ Center,5Cancer Research Center, Seoul National University Hospital, KoreaAim: Dialyzer reuse, first described in the 1960s, had many advantages ofeconomical and clinical aspects. Especially, home hemodialysis system needsreuse of dialyzer. To construct a new home hemodialysis system using pul-satile pump, a study on dialyzer reuse with pulsatile pump is required. [Theexperimental results of rinsed dialyzers (TORAY BS-1.6L; Toray, Japan)using pulsatile pump that are used in a local dialysis center are described inthis paper.] Methods: Dialyzer rinsing was performed by two methods, firstone was Back washing by reverse ultrafiltration; distillation water was deliv-ered by a large blood sack and a small blood sack into dialysate and bloodinflow lines, respectively. Dialysate part pressure was set higher than bloodpart by using valve. Another one was Push and Pull; distillation water wastransported by a large blood sack into dialysate inflow line and distillationwater was drained by a small blood sack from blood outflow line. Duringrinsing, pump rate was 30 beat/min for 30 minutes. Results: In back washingmethod, UFR (ultrafiltration rate) increased from 23% to 59% and bloodvolume increased from 31% to 68% due to the rinsing. In push and pullmethod, UFR was enhanced from 17% to 75% and blood volume increasedfrom 31% to 66%. Conclusion: In these experiments, High TMP (trans-membrane pressure) generated in a moment by pulsatile pump is effectivedialyzer rinsing. Hence, we validated that dialyzer rinsing could applied intopulsatile pump.

P 062 HOW TO PREVENT HYPOTENSION IN HEMODIALYSISG. Casagrande1, U. Teatini2, G. Romei2, F. Miglietta1, R. Fumero1,M.L. Costantino1. 1Dept. of Bioengineering, Politecnico di Milano,2ASL G. Salvini, Ospedale Caduti Bollatesi, Milan, ItalyBackground: It is well accepted that end stage renal disease patients(ESRD) need a tailored dialysis treatment. The amount of fluid stored bythe patients during the interdialytic period is displaced both into the vas-cular compartment and the interstitial space in different percentagedepending on the patients characteristics. The aim of this work is to find anindex able to detect the fluid distribution at the beginning of the treatmentand its relationship with the patient behaviour during dialysis. Methods: Thedata of 80 dialysis sessions were analysed. Systemic pressure, blood com-position (hematocrit, total proteins content), blood volume % (BVM) andweight loss were repeatedly recorded. Patient weight and total proteincontent at the end of a session and at the beginning of the subsequent oneplay a fundamental role in the determination of the hydration index HI thatwas introduced as a novel instrument to study the patient hydration.Results: Two groups of patients were identified on the basis of different HIvalues. Each group is characterised by a distinct response in term of plasmarefilling during haemodialysis. At the beginning of the treatment plasma

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refilling rate is greater for the group of patients characterised by high HIvalues, while for the other group the onset of plasma refilling is delayed.Conclusions: The index HI enables the evaluation of the proneness of thepatient to hypotension at the beginning of each treatment. A customizeddialysis treatment might be performed by using other indexes of easy andfrequent evaluation during the treatment together with HI, so to preventadverse episodes such as hypotension.

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P 063 TACHYARRYTHMIA CONTROL MACHINET. Yambe1, S. Maruyama2, E. Asano3. 1Institute of Development, Aging &Cancer, Tohoku University, Sendai, 2Institute of Fluid Science, Tohoku Uni-versity, Sendai, Japan, 3Children’s Hospital of Michigan, Detroit, USATachyarrhythmia limited the patient’s quality of life. In the patients withtachyarrhythmia, accessory pathway formed reentry, so, surgical operationwas performed to cut the pathway. However, there is a possibility of the complication in the surgical procedure and interventional ablation. In thisstudy, new tachyarrhythmia control method was invented and reported. Inthis system, electrical cooling elements was inserted in the pericardiumthrough the small incision aand attached to the accessory pathway. When thepatients feels tachycardia, the switch was pushed by the patients. By switchon, the accessory pathway is cooled and a tachyarrhythmia attack is con-trolled.A battery is used in a patient with few attacks.Transcutaneous energytransmission system (TETS) is used in a patient with a frequent attack. Inthis system, if a patient feels a tachcardia, TETS will be used. Outer coil will be attached to the inner coil under the skin. Energy is supplied and aaccessory pathway is cooled. Now, we are studying the diagnosis algorithmfor the various kinds of tachyarrhythmia. If diagnosis is possible, the auto-matic control of tachycardia attack will become possible. It is expected thatit becomes good news for the patient of tachyarrhythmia.

P 064 EFFECT OF WEANING PROCESS OF MECHANICAL CIRCULATORY SUPPORT ON CIRCULATORY AUTONOMICNERVOUS SYSTEM EVALUATED BY POWER SPECTRAL ANALYSIS OF ARTERIAL PRESSURE WAVEST. Tsutsui, T. Kuwabara*, O. Shigeta, Y. Sakakibara, Y. Sankai*. Institute ofClinical Medicine and Institute of System Science & Engineering Mechan-ics, University of Tsukuba, JapanAim: It has been regarded that the power density values of high frequency(0.15 to 0.4 Hz) and low frequency (0.04 to 0.15 Hz) components of systemicarterial pressure represent the function of autonomic nervous system activ-ity. In this study, the power spectral analysis of systemic arterial pressurewas adopted for evaluation of the stress on circulatory control system ofpatients during mechanical circulatory support. Methods: In 35 patients, sys-temic arterial pressure signals were acquired every 2 hours at 100 Hz for 6minutes. power spectral analysis was carried out, and power density valueswere observed in 15 patients with mechanical circulatory support includingIABP (Intraaortic Balloon Pumping) alone in 11 patients, PCPS (Percuta-neous Cardiopulmonary Support) with or without IABP in 4 patients, andin 20 patients without mechanical circulatory support. Results: The nor-malized power spectral component in low frequency (LFAnorm) showedmarked depression (below 0.1) during weaning from mechanical circulatorysupport in 10 patients. There was significant negative correlation betweenthe duration of marked depression of LFAnorm and the LFAnorm valueon begining of weaning from mechanical circulatory support. On the con-trary, marked depression of LFAnorm was not observed in cases withoutmechanical circulatory support. Conclusions: Marked LFAnorm depressionon weaning from mechanical circulatory support indicated the stress onautonomic nervous system during the process. Sustained depression ofLFAnorm values was known to be related to poor prognosis. The powerspectral analysis of systemic arterial pressure offers a reasonable tool forevaluation of the stress on circulatory control system of patients with cir-culatory assist devices.

P 065 LASER BASED MEASUREMENT TECHNIQUES APPLIEDTO THE STUDY OF PROSTHETIC MECHANICAL HEART VALVESFLUID DYNAMICSM. Rossi, U. Morbiducci, L. Scalise. Department of Mechanics, UniversitàPolitecnica delle Marche, Ancona, ItalyThe fluid dynamic analysis applied in the bioengineering field could be seenas an useful tool for the investigation of some peculiar features of mechan-

ical devices implanted in the cardiovascular system and for the compre-hension of the functionality of these devices in order to reach a higherdegree of performance and subsequently to assure a better clinical outcomefor the patient. This study investigates the flow velocity field downstream ofa prosthetic mechanical heart valve using both laser Doppler anemometry(LDA), 2D and stereoscopic particle image velocimetry (PIV). The mainfeatures of LDA are the small measurement volume, the high temporal res-olution and repeatability of measurements. Although being a single-point,time-consuming technique, LDA is still the technique of choice for a high-accuracy fluid dynamic analysis of prosthetic heart valves. PIV is recentlyused in alternative to LDA. It is basically a full field measurement techniquethat furnishes measurement of instantaneous velocity vectors in a flow field,thus allowing us to map the entire velocity flow field. As well as LDA, PIVtechnique do not perturb the flow to be investigated. This essential prop-erty allows much more rapid results, and has gained sufficient temporal andspatial resolution to estimate velocity fields, depending on the degree ofinstability in the flow, provided that sufficient images are available to esti-mate the mean flow. We present a comparison of PIV two-dimensional andstereoscopic measurements to LDA measurements, performed under pul-satile, repeatable flow conditions in a mock loop properly designed to guar-antee optimal optical access. Comparisons of mean velocity obtained by thethree techniques are in good agreement except for where there is instabil-ity in the flow. This suggests that the test bench design guarantee the possi-bility to carry out measurements using both the “gold standard” (LDA) andthe more advanced techniques (2D and stereoscopic PIV) in investigatingthe flow characteristics associated with mechanical heart valves.

P 066 A PROBLEMS IMPLANTING CARDIOVASCULAR PROSTHESESA. Tedesco, G. Pallotti, M.C. Pallotti, M.G. Pallotti. Department of Surgicaland Anaesthesiological Sciences, Departiment of Clinical Medicine andApplied Biotechnology, Faculty of Medicine and Surgery University ofBologna “Alma Mater Studiorum”, Bologna, ItalyAim: to study the problems involved in implanting prostheses in the car-diovascular system and the possibility to patient survival. Discussion: whena graft is implanted into the cardiovascular system the first response byrecipient and the prosthetic device is made by the blood. Therefore, the keyquestion arising with these implants is what effects will be generated in thebody. Initially the system must adapt to the new circuit generated by the implantation of the prosthesis. The systolic wave travels throughout thepatient’s body into the cardiovascular system to generate the blood flow inthe vessels to transport the oxygen to all tissues throughout the body. Thiseffect goes on day by day, with a continuous harmonious movement deform-ing the structure of the vessel walls. The possibility of rejection must beinvestigated to eliminate in particular to exclude biochemical and geneticmatter, but the biomechanical properties of the prosthesis must also bestudied to avoid undesiderable side effects. Conclusion: the completedinvestigation addresses all types of prostheses used in for implantation inthe cardiovascular system.

P 067 STEREO-PIV MEASUREMENTS ON PROSTHETIC HEARTVALVE: COMPARISON BETWEEN PULSE DUPLICATORSM. Grigioni1, G. D’Avenio1, U. Morbiducci1, K. Hamilton2, C. Del Gaudio1.1Technology and Health Department, Istituto Superiore di Sanità, Rome,Italy, 2Helmholtz-Institute, Aachen, GermanyBackground/Aim: Even though international normatives for testing cardio-vascular devices exist since many years, there is not a unique way to applythem. In particular, pulse duplicators (PDs) for testing heart valves havebeen designed and built according to different concepts. In this work, wepresent measurements made on the same prosthetic device, with two widelyused PDs. Methods: The valve (a Sorin Bicarbon of 27-mm nominal size) wasmounted in the aortic section of each PD. The Sheffield University PD andthe RWTH Aachen PD were selected as physical models of the circulation.A glassblown aorta, realized in agreement to the actual anatomy of healthyindividuals, was positioned downstream of the valve, realizing the conditionof geometric similarity. The measurements, carried out with a solution of suitable kinematic viscosity, addressed the velocimetric study of the down-stream flow field by means of the stereo-PIV technique, capable of providingthe complete 3D velocity field as well as the entire Reynolds stress tensor. Aseries of 12 experimental phases, distributed along the cardiac cycle, waschosen to characterize the valve behaviour at the plane intersecting the valveaxis. Results: The well-known profile of three jets exiting the bileaflet valve

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in the plane crossing the leaflets was found with both experimental series. Acharacteristic phase effect was found, with the flow fields obtained on twoPDs (Sheffield University and RWTH) due to a phase lead dependent onPD. The extent of the vortex in the Valsalva sinus was much larger in theRWTH PD, on account of the different duration of the swirling motion in theventricular chamber, caused in turn by both the elasticity of the ventricle andits geometry. Conclusion: The comparison of the hemodynamical behavioursof the same bileaflet valve tested in two PDs clearly demonstrated the rele-vance of the way in which the valve performance itself is affected by themock-loop.A phase delay was observed in the valve mounted on the PD witha rigid ventricular chamber, highlighting the role of the local compliance, aswell as the geometric disposition of the upstream chamber with respect tothe valve axis, in determining the kinematic behaviour of the valve.

P 068 A NOVEL METHOD FOR MEASURING THE TORQUEACTING ON CARDIOVASCULAR IMPLANTS IN NMR SCANNERSG. D’Avenio1, R. Canese2, F. Podo2, M. Grigioni1. 1Dept. of Technology andHealth, ISS, Rome, 2Dept. of Cell Biology and Neurosciences, ISS, Rome,ItalyBackground/Aim: The use of NMR techniques is widespread in the clinicalfield and is becoming a tool also in the study of pathologies of heart andlarge vessels. The growing need for high resolution in very short time in MRinvestigation calls for increasing static fields. Moreover, magnetic fields upto 3.0 T are becoming commonplace in hospitals and the installation ofsystems at > 3T is increasing in research institutes. The question arises if car-diovascular implants such as mechanical heart valve prostheses can with-stand such increasing static fields. We propose a novel method for measuringthe torque acting on prosthetic implants subjected to the high static mag-netic fields of NMR scanners. Methods: The torque measurements havebeen performed with a torsion balance, realized with a thin copper wire(whose diamagnetic properties render it suitable for this task), mounted onthe scanner’s cradle. The contact between valve and torsion wire is ideallypoint-like, so that the global torque is the sum of the contributions of twotorsion bars. The deflection angle is calculated from the laser spot projectedon a graduated scale by the device under test. The torque is readily calcu-lated from the deflection angle and the geometrical parameters of the set-up. Mechanical valves of different type and brand have been tested in thesmall bore system Varian Inova 200/183 operating at 4.7 T. Results: Themethod has proved to be very sensitive, with respect to the other approachesfollowed in this type of characterization of prosthetic implants. A series ofmeasurements on the same valve, repeated with different torsion wire diam-eters, has confirmed that the method is reliable and yields repeatable results.In general, the measurements have confirmed the safety of the tested valves,previously reported at smaller magnetic fields. Conclusion: The proposedmethod for torque measurements is capable of providing a quantitativeevaluation of the interaction between prosthetic device and NMR scanner’smagnetic field. Such information, besides being valuable for confirming thesafety of a diagnostic investigation at a given magnetic field on an implantedpatient, can be used for deriving functional parameters for the predictionof the device-field interaction that could occur at higher static levels.

P 069 MECHANICAL APPROACH FOR PROGRAMMINGOPTIMAL PACING IN PACEMAKERS WITH LASER DOPPLERVIBROMETRY TECHNIQUE: PRELIMINARY CLINICAL RESULTSL. Scalise1, U. Morbiducci1,2, M. De Melis1, M. Grigioni2, G. Corbucci3,P. Bocconcelli4, A. Pierantozzi4. 1Department of Mechanics, UniversitàPolitecnica delle Marche, Ancona, 2Technology and Health Department,Istituto Superiore di Sanità, Rome, 3Vitatron Medical Italia, Bologna,4Division of Cardiology, St. Salvatore Hospital, Pesaro, ItalyTo achieve adequate mechanical performance of the myocardium withpacing it is essential to maintain good mechanical synchronization of theheart chambers. For this purpose, optimal programming of the paced atrio-ventricular and interventricular delay is needed, mainly in atrio-biventricular pacing. Several criteria are available to assess the effect ofpacemaker programming, the most widely applied makes use of Echocar-diography plus ECG. The vast majority of patients with three chamberspacemakers are not optimized with Echo because it is a time-consuming,expensive, operator-dependent method. Moreover, Echo procedure for syn-chronization is based on the observation of few cardiac cycles. To overcomethis drawback, we developed a radical new approach by means of which wemeasured, using laser Doppler vibrometry, the motion’s properties of theexternal surface of the human chest. The method, named vibrocardiogra-

phy (VCG), was previously tested to monitor without any electrical con-nections the heartbeat in healthy subjects. In particular, we pointed a laserbeam (about 2.5 m distance) at a point on the chest wall corresponding tothe apex of the left ventricle of a subject with a biventricular pacemakerimplanted. Echo, ECG, and VCG signals were simultaneously recorded. Wecarried out measurements in correspondence of four different pacing strate-gies: biventricular, only left ventricular, only right ventricular pacing, spon-taneous rhythm. One minute of VCG recording was segmented and theaveraged beat was extracted (on about 60 heart beats). Preliminary resultsclearly state, on the basis of Echo observations, the possibility of devising aprocedure for automatic determination of optimal pacing programmingonly by VCG signals. Moreover, VCG could be used to evaluate the pacingstrategy to be used for the optimal mechanical resynchronization of ven-tricular chambers in patients with heart failure. Our first clinical trial sug-gests that VCG approach to heart mechanics evaluation may be a reliablemethod of strategy optimization during pacing.

P 070 LINEAR BLOODPUMP—A NEW CONCEPT FOR FLUIDPROPAGATION IN CARDIAC ASSIST DEVICES OR TOTAL ARTIFICIAL HEARTM. Grossmann1,W. Juettner2, J. Landrath3, F.A. Schoendube1. 1Thoracic Car-diovasc Surgery, Georg-August University, Goettingen, 2Industrial Com-puter Science, FH Wolfsburg, Wolfsburg, 3Electrical Drive Engineering, FHHannover, Hannover, GermanyLong-term cardiac support and total artificial heart with displacement orrotary blood pumps is still crucial due to blood cell damage, hemolysis,thrombus formation or postoperative bleeding. We propose a new conceptthat is not in need of membranes or rotating properties, but aims to mimicthe displacement of an inlet valve against an outlet valve in the naturalcardiac cycle. In addition, the new concept allows the use of Carbon at allblood-contact surfaces combined with a nearly laminar flow profile. Weinvestigated the construction and performance of a linear induction motor,which can be controled by different parameters during one cycle. At the endof a tube (diameter 3 cm, length 10 cm) an outlet valve is fixed and a secondvalve moves within the tube against this valve, driven by a magnetic linearmotor (see figure). With this design the mean energy loss is calculated toapproximately 3 W at a flow rate of 4.8 l/min against a load of 16 kPa. Asthe gap between inner wall of the tube with carbon surface and the movingpiston can be reduced to at least 1 micrometer a laminar flow of low vis-cosity results. The blood pump can be designed for high frequencies and low displacement volumes making cardiac assist for new-borns and infantsfeasible.

P 071 SELF-MANAGEMENT PROTOCOL FOR A MOVING-ACTUATOR TYPE ARTIFICIAL HEARTK.W. Nam1, J. Chung1, S.W. Choi1, K. Sun2, B.G. Min3. 1InterdisciplinaryProgram in Medical and Biological Eng. Major, Graduate School, SeoulNatl’ Univ (SNU), 2Korea Artificial Organ Center, Korea Univ., 3Dept. ofBiomedical Eng., College of Medicine, SNUAim: After the surgical implantation of an artificial heart, a patient whoequips the artificial heart must be discharged from a hospital as soon as pos-sible and live a normal life style. However, there always exists a possibilityof abnormal operation of the implanted device during discharging period.Therefore, for the safe of the outpatient, continuous operating status mon-itoring protocol for the patient-equipped artificial heart is needed. In this study, we developed a self-management protocol for an outpatient who equipped a moving-actuator type pulsatile artificial heart, AnyHeart.Methods: Developed self-management protocol consists of 5 parts; first,motor current based abnormal pumping status detection part that analyzesa motor current signal and detects preset abnormal pumping statuses;second, pump resuming part that restarts the blood pumping operationusing backup motor driver when the blood pump stopped abnormally by anabrupt electronic part error in main motor driver; third, self-diagnosis partthat analyzes each electronic parts in the main motor driver and identifieswhere the error occurred; fourth, remote alarming part that transmits analarm message to preset authorized staffs to notify them of an abnormalpumping status occurrence and its likely cause; and fifth, remote monitor-ing part that transmits real-time operating data to a remote monitoring com-puter that is connected with the controller via a cellular link. Using thisremote monitoring protocol, authorized persons can connect to the patient-equipped artificial heart controller anytime and anywhere if the outpatientis in the service available area of cellular phone network. Results: Results

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of in vitro performance experiments showed that the developed protocolcan detect simulated abnormalities in motor current signal, manage theoperating status of the blood pump at emergency, transmit an alarmmessage, and construct a monitoring link with a remote computer as desired.Conclusion: The developed self-management protocol showed satisfactoryperformance during in vitro experiments. By applying this self-managementprotocol we hope that system reliability and patient safety will be substan-tially improved. Acknowledgment: This study was supported by the BK 21project.

P 072 EFFECT OF CARDIOVASCULAR DEVICES ON HEARTFAILURE IN A MOCK CIRCULATION LOOPD.L. Timms1, K. McNeil1, M.J. Pearcy2. 1The Prince Charles Hospital,2Queensland University of Technology, Brisbane, AustraliaBackground/Aim: This purpose of this study was to evaluate the hemody-namics of a combined systemic and pulmonary mock circulation loop repro-ducing many different types of heart disease. Methods: Systemic andpulmonary circulation loops were connected in series to reproduce thehuman cardiovascular system. The system incorporated beating left andright pneumatic hearts as well as arterial and venous compliances and resis-tances to reproduce a pulsatile hemodynamic environment. The modifica-tion of cardiac and vascular parameters provided the opportunity to mimicmany types of heart disease. The ability to insert and evaluate mechanicalcardiovascular devices to correct these diseases is provided, with theirrestoring effect on pathological hemodynamics easily evaluated. Results:Normal physiological conditions of rest and exercise were initially producedto validate the loop performance against accepted hemodynamic data.Many forms of heart disease were then induced. Varying degrees left-right-and bi-ventricular heart failure were demonstrated, resulting in theexpected combination of pulmonary and/or systemic hypertension. Con-genital septal defects were recreated by valve actuation, with associatedhemodynamics recorded. The insertion of a left ventricular assist device pro-vided evidence of reduced pulmonary pressure and thus congestion. Con-clusion: This compact rig can effectively reproduce the pathological effectof common types of heart disease on the complete cardiovascular system.This provides a suitable environment to provide valuable device perfor-mance feedback prior to expensive in-vivo animal trials.

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P 073 NUMERICAL ANALYSIS AND EXPERIMENTAL VALIDA-TION OF AN INNOVATIVE FLUID FILM BEARING FOR ROTARYBLOOD PUMPSM. Akdis, M. Hormes, M. Martin, H. Reul†. †passed away on Nov. 3, 2004.Helmholtz Institute for Biomedical Engineering, RWTH Aachen, GermanyBackground: Rotary blood pumps have significantly gained interest as longterm implantable ventricular assist devices for the treatment of cardiacinsufficiency. Major risks associated with rotary blood pumps includehowever thrombus formation due to either stagnant flow or temperaturerise as well as increased hemolysis rates due to high shear flow in criticalpump regions such as blood contacting rotor bearings. Methods and Results:A new fluid film bearing based on the Lomakin-Effect has been developedand validated by means of CFD analysis and experimental studies. In con-trast to conventional hydrodynamic bearings this innovative approachenables larger gap sizes and therefore reduces the risks of hemolysis andthrombosis. In vivo studies revealed excellent hemocompatibility of thepump and bearing concept. Conclusions: Based on this bearing technologya mixed flow rotary blood pump is currently being prepared for clinicalapplications that will serve as a cost-efficient midterm to long-term VADsystem.

P 074 NUMERICAL ANALYSIS FOR DESIGNING A NEW AORTICCANNULAT. Fujimoto1, M. Aruga1, S. Nakano1, N. Kabei2, M. Yoshida3, M. Umezu3.1Shibaura Institute of Technology, Tokyo, 2Saitama Cardiovascular and Res-piratory Center, Saitama, 3Waseda University, Tokyo, JapanBackground: We have been developing a newly designed aortic cannulawhich can be used for left ventricular bypass. Two rectangular sheets ofnylon were used to make the cannula. These two sheets were welded inter-mittently at 8-mm intervals using an ultrasonic welder. The cannula isdesigned so that it is folded to a small outer diameter (5 mm) when insertedinto the aorta through the skin. After being positioned in the aorta, the

space between the sheets is filled with air to expand the diameter of thefolded cannula up to 17 mm. The cannula was fixed into a mock circulatorysystem, through which physiological saline was perfused, and experimentswere conducted to evaluate the characteristics of the cannula. From theresults of the experiments, two problems were revealed as follows; (1)Decrease in the inner diameter of the cannula when it is expanded, (2)Fragility at the welded spots. The purpose of this study is to find some cluesto solve these problems. Method: It is necessary to reveal the relationshipbetween the air pressure in the space between the sheets and the transfor-mation of the cannula. In order to reveal the relationship, numerical analy-sis was conducted using a FEM computer application. In the 2 dimensionalanalyses, changes in the diameter of the cannula in expanded condition werecalculated when the thickness of the sheets was increased. In addition,stresses on the sheets were calculated in the 3 dimensional analyses. Results:When the thickness of the inner sheet was increased up to 90 mm from 45 mm, the inner diameter was shown to extend by 1.4 mm in the 2 dimen-sional analyses. There is a continuous increase in the stress on the weldedspot of the sheets accompanied by corresponding increment of the air pres-sure in the space between the sheets. Conclusion: These analytical resultssuggest that these problems will be solved by changing the conditions offabrication such as the thickness of the material, the welding interval, theair pressure to expand the cannula, and so on. We are remaking the cannulaon basis of the results to be used for left ventricular bypass in clinical use.

P 075 METHOD TO DETERMINE INTRAVENTRICULAR PRES-SURE AND SHEAR STRESS BY DOPPLER COLOR ECHOCAR-DIOGRAPHY AND ITS APPLICABILITY TO VENTRICULARASSIST DEVICESJ.C. Antoranz1,2, M.M. Desco1,2, R. Yotti3, J.L. Rojo4, J. Bermejo3. 1DeptFísica Matemática y Fluidos, LMAI, UNED, 2Unidad de Medicina y CirugíaExperimental, Hospital General Universitario Gregorio Marañón, HGGM,3Departamento de Cardiología No Invasiva, HGUGM, 4ETSIT, Universi-dad Carlos III, Campus de Leganés, Madrid, SpainBackground: One of the most important problems in the design of VAD isto know the magnitude of the shear stresses and the temporal derivative ofthe intraventricular pressure (dpdt) inside the pump. All these physical mag-nitudes are related to the destruction of erythrocytes and platelets by,approximately, a cubic power law. We propose a method already developedby our group to study the intraventricular gradients in patients to get non-invasive cardiac indexes. Methods: High-fidelity micromanometers wereplaced surgically in the left ventricle of eight minipigs, and synchronic colorDoppler echocardiographic images and pressure signals were obtainedduring different hemodynamic conditions. Color-Doppler m-mode record-ings are digitally postprocessed with a software algorithm which decodesflow velocity and fits a bivariate spatio-temporal tensor-product smoothingspline. Temporal and spatial derivatives are then analytically calculatedfrom the fitted velocity data, allowing to solve the one-dimensional Euler’sequation. Results: Both techniques for measuring pressure differencesbetween three intraventricular locations (the apex, the mid-cavity and theoutflow tract) give the same results. Conclusions: Intraventricular gradientsare accurately measured by Doppler echocardiography. The method is suit-able for determining pressure temporal as well as transversal spatial veloc-ity derivatives inside the VAD, and consequently stress tensor and dpdt.

P 076 FLOW EVALUATION OF STENTS AND FILTERS INCAROTID ARTERY MODELSD. Liepsch1, G. Berger2. 1University of Applied Sciences, 2Kinikum rechtsder Isar der TU München, GermanyBackground: Stent implantation treatment of cardiovascular disease is notwithout risk as clots can be transported into the brain. Restenosis occurs in10–20% of cases. Alterations to flow behavior can lead to clotting and re-stenosis. Studies show the importance of flow behavior, shear rate and shearstress, the interaction between the fluid and the vessel wall and the bloodcells. Changes in flow rate can create physiologically abnormal velocity fluc-tuations. Higher velocity fluctuations and flow separation can lead to shearstresses and recirculation zones, where platelets aggregate or adhere to thewall. Similar processes arise just after implantation of stents. We studiedfour types of stents (a self-X stent, a Wall stent, a covered stent and animproved covered stent) in a silicon rubber model of a carotid artery to testthe influence of variations in stent design, especially the direction and meshof the wires, the in- and outflow, the stretching, surface roughness and theposition of the stent, on flow behavior. Of special interest were flow differ-

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ences between the covered and uncovered stents, the flow resistance, theposition of stent in the arterial model and the entrance flow angle. Methods:Silicon rubber models of the carotid bifurcation were prepared, having acompliance similar to the vessel wall of a common carotid artery. Themodels are transparent and elastic and duplicate the inner surface of theartery wall. The filters were tested with and without particles. The fluid wasa mixture of polyacrylamide and water, and dimethylsulfoxide and waterexhibiting the viscoelastic flow behavior of human blood with a hematocritof 45% at 37°C. The velocity was measured with a one-component He-NeLDA. Discussion: The because the uncovered wires extend into the stentshould not be implanted at 90° cross section at the outflow and disturbedthe flow. A longer stent should be set, so that the wire at the end doesn’treach into the lumen. No significant changes in flow rate were found in theempty, Self-X, covered and improved covered stents. However, a reductionof flow disturbances at the outflow in the improved covered stent was found.The position and the length of the stent are important, because shorterstents influence the flow behavior strongly and give rise to re-stenosis, espe-cially in arteries with smaller diameters.

P 077 MODEL OF ARTERIAL AND PERIPHERAL CIRCULATIONWITH LOCAL REGULATION AND FILTRATION THROUGH CAPILLARY MEMBRANE FOR THE STUDY OF VASOMOTIONAND ASSISTED CIRCULATIONE. Lanzarone, G. Baselli, R. Fumero, M.L. Costantino. Department of Bio-engineering, Politecnico di Milano, Milan, ItalyBackground: Arterial models used to simulate patients in particular condi-tions are often passive models, without the adaptation to physiological orpathological conditions. So they can’t describe both the always present vaso-motion and the difference in behaviour during clinical applications likeextra corporeal circulation or dialysis. Methods: These phenomena areinvestigated with a lumped parameter model of the systemic arterial circu-lation, made by 63 RCL segments of large arteries, with the characteriza-tion of viscoelastic wall behaviour, and 30 peripheral districts in whichperipheral vasomotion, due to myogenic and methabolic controls, wasstudied and was associated to the interstitial liquid exchange through cap-illary membrane. Blood properties were also variable, depending on tem-perature, hematocrit and proiteinic concentration; Fahareus-Lindqvisteffect was considered. Parameters alterations deriving from pathological orclinical conditions, like during extra corporeal circulation, were studied.Results: A remarkable autoregulatory activity of peripheral districts wasfound: peripheral blood flow keeps constant over a wide pressure range and,when regulated, oscillates around the physiological value. The presence ofcontinuous flow, fall in blood temperature, hematocrit reduction, oxygenconsumption alteration and proteinic concentration reduction are consid-ered to account extra corporeal circulation conditions and simulate alteredbehaviour in these conditions, particularly the difference between a contin-uous and a pulsatile flow and the peripheral edema onset. Conclusion: Thismodel adapts to the pathological or clinical conditions in order not to usean arterial tree derived from physiological conditions when these conditionsaren’t present.

P 078 2D PIV STUDY OF THE FLOW DOWNSTREAM TWO PRO-TOTYPES OF A NEW MONOLEAFLET ARTIFICIAL AORTICHEART VALVE PROSTHESISR. Kaminsky1,2,3, K, Kramm1, H.J. Weber2, A.P. Simons2, S. Kallweit3,P.R. Verdonck1. 1Hydraulics Laboratory, Institute of Biomedical Technology,Ghent University, Belgium; 2Laboratory of Artificial Organs and Cardio-vascular Engineering, University of Applied Sciences Aachen, DivisionJuelich, 3ILA GmbH, Juelich, GermanyAim: Monoleaflet artificial heart valve prosthesis are commonly used forheart valve replacement. Although there are different designs commerciallyavailable, the optimal hemodynamical solution is still not available. The different flow pattern among these heart valve prosthesis are related to the miscellaneous geometry of the hinges, occluder and the housing ring. Inthis experimental study the flow downstream of two new prototypes ofmonoleaflet aortic heart valve (University of Lodz, Poland) were investi-gated by means of 2D Particle Image Velocimetry (PIV). Methods: The pro-totypes, Valve 01 and Valve 02, were mounted into the mock aorta of thecommercially available heart valve simulator Vivitro Superdupr (VivitroSystem Inc., Victoria). The major difference between the valves is theiropening angle. The maximum opening angle of the Valve 01 is 70° and ofthe Valve 02 is 54°. A standard 2D PIV system (ILA GmbH, Juelich) was

coupled to the traverse unit allowing various position in axis perpendicularto the measured plane. Left ventricular and aortic pressure were monitored(Setra Systems, Boxborough) and simultaneously a volume flow was quan-tified using electromagnetic flowmeter (Vivitro System Inc., Victoria). PIVmeasurements of the flow velocities past the valve plane were performedboth in longitudinal axis at the central plane orthogonal to the plane of thehinges and at the lateral plane with an offset of 6 mm parallel to the centralplane. The pulse duplicator rate was set to 75 bpm (rest conditions) and to162 bpm (exercise conditions). For each investigated plane and heart rate a10 msec sampling rate and 100 double cross-correlation images for the PIVperformance were acquired. Results: Comparison of the flow pattern con-firms that the opening angle and maximum velocities are higher for Valve01 both a rest and during exercise.

P 079 STEREO PARTICLE IMAGE VELOCIMETRY ON MECHAN-ICAL HEART VALVE PROSTHESISK. Hamilton1, G. D’Avenio2, U. Morbiducci2, U. Steinseifer1, M. Grigioni2.1Helmholtz-Institute, Aachen, Germany, 2Instituto Superiore di Sanità,Rome, ItalyBackground: Low hemolysis and low thrombogenicity are importantrequirements for biomedical devices (e.g. cardiac assist devices and mechan-ical heart valves). To ensure the fulfillment of those requirements it is essen-tial to gain profound knowledge about the flow behaviour in these devices.In the present study the flow downstream of a bi-leaflet mechanical heart valve prosthesis (TAD 27), was investigated by Stereo Particle Image Velocimetry (Stereo-PIV). Methods: A circulatory mock-loop wasemployed as a hydraulic model of the left human circulatory system to gen-erate physiological pressure and flow conditions in aortic valve position. Arealistic glass blown aortic root model was used to mimic anatomic condi-tions. As test fluid a sodium-iodine-water-glycerine solution was used, fea-turing blood analogue dynamic viscosity and matching the refractive indexof the glass blown aortic root model. Alumin (10 mm) was added to seed thefluid. Results: The aortic cross section flow field was investigated at differ-ent time instances of the heart valve cycle. 3-dimensional velocity compo-nents (u, v, w) were evaluated including the calculation of Reynold’s shearstress, vorticity and turbulent kinetic energy. Conclusion(s): The visualisa-tion of the 3-dimensional flow field downstream a mechanical heart valveby Stereo-PIV provides the best opportunity to examine the non-stationaryflow behaviour during a heart valve cycle. Flow stagnation may be locatedfor thrombosis prediction. Furthermore calculated shear stresses give anindication on erythrocyte exposure, hence, haemolysis potential of the flowassociated to the heart valve.

P 080 ASSESSMENT OF HYDRODYNAMIC PROPERTIES OFHEART VALVES FOR ARTIFICIAL HEARTK.H. Kim1,3, G.S. Jeong1,3, M.W. Jung1,3, C.B. Ahn1,3, J.J. Lee2, C.M. Hwang2,3,Y.T. ka*wk3,4, H.S. Son3,4, Y.F. Fang3,4, K. Sun2,3,4. 1Biomedical Engineering ofBrain Korea 21 Program, Korea University, 2Department of BiomedicalEngineering College of Medicine, Korea University, 3Korea Artificial OrganCenter, Korea University, 4Department of Thoracic and CardiovascularSurgery, College of Medicine, Korea UniversityBackground/Aim: Hydrodynamic properties are important element of heartvalves. Polymer heart valves are advantageous to mechanical heart valves,by low thrombogenic surface modification, higher compliance, and low cost.In this study, the comparative evaluation of mechanical heart valves andpolymer heart valves were produced by in vitro mock circulation test forartificial heart application. Methods: In this study, Bjork Shiley monoleafletvalve and Sorin bicarbon bileaflet heart valve, floating type monoleafletpolymer valve and trileaflet polymer valve were used for in vitro evalua-tion. Donovan type mock circulation system was used for the in vitro test.For the pulsatile flow generation, the pneumatic ventricular assist consoleand blood pump, developed in our group, were connected with the mockcirculation system. The pressure at distal and proximal position of the heartvalves were measured and stored in lap top computer via analog-digital con-verter. Results: Across the mechanical heart valves, the pressure drop washigher in monoleaflet heart valve than bileaflet heart valve. As for the float-ing type polymer heart valve, the pump output was lower than both of themechanical heart valves. The regurgitation of the mechanical heart valveswas higher than polymer heart valves. Conclusion: The floating typepolymer valve showed resistance than mechanical heart valves, which maybe due to the peripheral flow characteristics, the floating leaflet supportingframe increases the flow resistance under same condition. Polymer valves

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were superior to mechanical heart valves in regurgitation, due to the com-pliant property of the polymer leaflet and close contact to the frame andreduce the leakage volume. For the design of polymer heart valve, the pres-sure drop and flow resistance have to be take into account. Acknowledge-ment: This study was supported by a grant from the Korea Health 21 R&DProject, Ministry of Health &Welfare, Republic of Korea. (02-PJ3-PG6-EV09-0001).

P 081 TRADITIONAL PUMP DESIGN THEORY IN HEART PUMPDESIGN AND CFD ANALYSISY. Wang, C.T. Ying. The Department of Engineering Physics, Tsinghua UniversityA ventricular assist device (VAD) has been designed and studied in thisarticle, which is designed according to the traditional axial pump designtheory and adjusted by mechanism and computational fluid dynamic (CFD).The main design progress is reached by the design theory, including headcoefficient, blade length, blade angel, hub diameter, shroud diameter and soon. Another way to finish the progress, CFD is also used, which help usdeciding the blade number, and adjust the parameters from the designtheory. The procedure in stationary conditions are studied and presented.Pressure, flow rate, flow vector and stress are studied in the way of CFDsimulation. The simulation environment is fluent which is supported byFluent Inc. Key words: Ventricular Assist Device, traditional pump designtheory, CFD simulation.

P 082 HISTORY OF BLOOD PUMP DEVELOPMENT AT THEHELMHOLTZ INSTITUTE AACHENM. Akdis, H. Reul†. †passed away on Nov. 3, 2004. Helmholtz Institute forBiomedical Engineering, RWTH Aachen, GermanyAccording to the REMATCH study mechanical circulatory support systemsprovide significant advantages over medical therapy options for the treat-ment of congestive heart failure. Worldwide, a series of blood pumps arebeing developed that are either in developmental stage or have alreadyentered the clinical arena. Through a 15 year R&D work at the HelmholtzInstitute Aachen (HIA) various blood pump concepts have been workedout and realized as marketable products, ranging from pulsatile VAD andTAH systems to different types of rotary blood pumps. Development of dis-placement blood pumps have focused on different activating principles suchas pneumatic and electromechanic systems, whereas rotary blood pumpstudies have concentrated on various bearing concepts such as shaft seals,blood immersed mechanical bearings and non-contact bearings. Validationof each pump type included numerical analysis based on CFD as well asexperimental studies on in vitro and in vivo performance of the pumpsystem in question. The aim of this paper is to summarize the performedresearch work at the HIA and to transfer the acquired experiences forfuture applications of blood pumps with a special focus on bearing conceptsand long-term applications.

Organ Transplantation

P 083 EFFECTS OF FTY720 ON LYMPHOCYTE SUBSETSEXPRESSING DIFFERENT HOMING RECEPTORS IN KIDNEYTRANPLANTATIONM.L. Cappuccilli, D. Conte, M. Ortolani, P. Todeschini, M. Piccari,G. Mosconi, M.P. Scolari, S. Stefoni. Institute of Nephrology, Dialysis andRenal Transplantation, S. Orsola University Hospital, Bologna, ItalyBackground/Aim: FTY720 (FTY) is a novel immunosuppressant able todetermine peripheral blood lymphopenia through lymphocyte homing, amechanism of migration of circulating lymphocytes from peripheral bloodto secondary lymphoid organs.The study was designed to investigate thepathway of FTY-driven homing during the first month following kidneytransplantation. Methods: Ten consecutive kidney recipients, transplantedat our centre in 2004, were included in the present investigation: 5 patientsreceiving FTY were compared with 5 controls treated with MMF (bothdrugs in combination with CsA and steroids). The lymphocyte subsets andthe surface expression on peripheral T cells of homing receptors CCR5,CCR7, CXCR4, CD62L, CD49d and CD11a were evaluated by flow cytom-etry. Differences between pre-transplant (day 0: prior to drug administra-tion) and post-transplant (day 1, day 4, day 7, day 14 and day 30) valueswere analyzed by Student’s paired t-test. Results: In patients treated withFTY, the decline of circulating lymphocytes was significant during the entiremonth, to the maximum extent after the first oral dose of FTY (day 0:

1465.0 ± 167.3 cells/ml vs day 1: 209.3 ± 60.9 cells/ml; p < 0.001). A significantreduction of all lymphocyte subsets, except NK cells, was observed. The T cytotoxic/suppressor (CD3+CD8+) and B (CD3-CD19+) cells remaineddecreased until day 7, afterward returning to baseline (pre-transplantvalue), whereas the decline of T helper lymphocytes (CD3+CD4 +) was sig-nificant during the whole monitoring period. Concerning homing receptors,our data seem to support the hypothesis that T helper cells expressingCD62L are the main target of FTY: in all our assays, the absolute counts ofCD4+CD62L+ lymphocytes were reduced to a greater extent comparedwith total CD4+ cells. Besides, the T-cells bearing the other surface markersfollowed a fairly parallel course with overall CD4+ or CD8+ lymphocytes.In the patients receiving MMF, the total lymphocytes declined significantlyat day 1, returning to the baseline within day 4. All the lymphocyte subsetsexpressing the surface markers studied here showed a similar decline to thatof overall lymphocytes. Conclusions: Our results seem to indicate that theeffects of FTY are differential in the T-cells subsets and they depend on spe-cific homing receptors.

P 084 SURGICAL ASPECTS ON DOUBLE KIDNEY TRANSPLAN-TATION IN OUR EXPERIENCEB. Nardo1, V. Pacilè1, R. Bertelli1, P. Beltempo1, R. Montalti1, L. Puviani1,G. Cavallari1, M. Licursi1, G. Fuga1, S. Stefoni2, A. Faenza1. 1Department ofSurgery, ICU and Transplantations, 2Nefrology, Dialysis and TransplantationUnit, University of Bologna, ItalyBackground/Aim: Double-kidney transplantation is performed usingorgans from marginal donors with an histological score not suitable forsingle kidney transplantation. The aim of the study is to verify the resultsobtained with double-kidney transplantation in term of graft and patientsurvival and complications. Methods: Between september 2001 and sep-tember 2004, 16 double-kidney transplantation were performed in ourcenter. The recipients’ mean age was 62,6 ± 3,2 and they were 2 female and14 male. The indications for the kidney transplantation were: polycysticdisease (3 patients), chronic glomerulonephritis (12 patients) and refluxnephropathy (1 case). The mean number of mismatches for HLA A, B eDR was 3,6 ± 1,1. The donors’ mean age was 65 ± 8,8 and ten of them hadat least one risk factor for the renal function (hypertension, smoke, dia-betes), with a mean creatinin clearance of 82,4 ± 32,7 mL/min, computedwith co*ckcroft and Gault formula. The kidneys were all perfused withCelsior solution and the mean cold ischemia time was 17,6 ± 2,7 hours. Inall cases a kidney biopsy was performed to evaluate the damage and themean biopsy score was 4,25 ± 0,45. Immunosuppressive therapy for allpatients included anti-IL-2 receptor antibodies, corticosteroids, tacrolimusand mofetil micophenolate. Results: Eight patients had a good renal post-operative function while the other eight had an acute tubular necrosis. Twoof the patients who had a severe acute tubular necrosis, never had a recov-ery of the renal function. There was only one episode of acute rejection,while the incidence of urinary complications was 31,2%; there were two sur-gical revisions for intestinal perforation. The graft and recipient survival was78,1% and 100% and 78,1% and 93,7% at 3 and 36 months. Conclusions:Double-kidney transplantation is a safe way to face the organ shortage.Moreover the score used in this study is useful to determine whether akidney should be refused or suitable for single or dual-kidney transplanta-tion. The results of our initial experience are encouraging, but this series aretoo small in number to consent a conclusive statement.

P 085 VARIATIONS OVER TIME IN QUALITY OF LIFE INKIDNEY TRANSPLANT PATIENTSK. Mattarozzi1, P. Todeschini2, G. Cangini1, C. Campi1, G. Mosconi2,C. Cipolli1, S. Stefoni2. 1Department of Psychology, University of Bologna,2Nephrology, Dialysis and Renal Transplantation Unit, S. Orsola UniversityHospital, BolognaBackground/Aim: The increasing rates of long-term survival for kidneytransplanted patients make of interest not only to establish how much theirquality of life (QOL) is improved, but also how it varies over time. Health-related QOL is a multidimensional construct: therefore, we ascertained howits main components vary, by comparing the scores obtained at SF-36 HealthSurvey by patients awaiting for transplantation with those obtained bytransplanted patients. Methods: The health-related QOL was measured bymeans of MOS SF-36 Health Survey on 45 dialyzed patients awaiting trans-plantation and 45 successfully transplanted patients (i.e., without rejectionor further dialysis), 18 of whom had undergone transplant 3 months before,18 of whom 18 months before and 9 from 60 or more months before. All

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patients examined were not cognitively impaired or moderately depressed,as indicated by their scores at Mini Mental State Examination and BeckDepression Inventory. Results: The scores of the 8 scales of SF-36 were sep-arately analyzed using a one-way ANOVA. Significant differences betweengroups of patients were observed on the scales of Physical functioning, Role-physical and General Health. Post-hoc pairwise comparisons showed thatthe scores of 18-months transplanted patients were higher (and, thus, QOLwas better) than those of all other groups for Physical functioning, Rolephysical and General Health. Moreover, the scores also of 3-months trans-planted patients were higher than those of non-transplanted patients. Con-clusions: With the caution suggested by the cross-sectional nature of thestudy and the small amounts of patients assessed, the present findings indi-cated that a) only some components of QOL are perceived (all related tophysical dimensions) as improved by transplanted patients and, b) for alimited period of time, as after 5 or more years no component of SF-36 oftransplanted patients resulted significantly better with respect to dialysedpatients. Further studies are needed to corroborate these indications as wellas to enlighten why psychosocial dimensions are perceived as not substan-tially improved.

P 086 PROTOCOL BIOPSIES IN KIDNEY TRANSPLANT RECIPI-ENTS: HISTOLOGICAL FINDINGS AND ALLOGRAFT FUNCTIONAT 1-YEARG. Spasovski1, J. Masin-Spasovska1, S. Dzikova1, G. Petrusevska2,B. Dimova2, L. Lekovski3, Z. Popov3, N. Ivanovski1, M. Polenakovic1. 1Dept.of Nephrology, 2Dept. of Pathology, 3Dept. of Urology, University of Skopje,MacedoniaAim: The findings of chronic allograft nephropathy (CAN) before deterio-ration of the graft function and histological changes of subclinical or bor-derline rejection (SR/BR) remain uncertain, especially concerning thepossibility for pulse corticosteroid therapy. Our study aimed to identifySR/BR and histological markers of CAN in protocol kidney biopsies andtheir possible impact on graft function. Methods: 20 paired kidney allograftbiopsies performed at 1 and 6 months were reviewed according to the Banffscoring scheme and serum samples taken at scheduled intervals. Results:10% of the biopsies showed no lesions. At first month BR was shown in35% and SR in 10% of the patients. At 6 months the proportion of thesefindings was even higher, namely, 40% and 30%, respectively. Mean CANscore (sum of histological markers for chronicity) increased significantly onthe 6-month biopsy, 2.15 ± 1.5 vs 4.3 ± 2.47 (p < 0.01). Mean calculated cre-atinine clearance deteriorated from 1 to the 6 month value (71.9 ± 17.2 vs63.2 ± 22.6; p < 0.05), but significantly improved at 12 months after the trans-plantation (63.2 ± 22.6 vs 69.4 ± 23.6; p < 0.01). When divided according toa progressive rise in serum creatinine above 200 mcmol/L, or in absolutevalue more than 20% in the interval from 6 to 12 months, the group withgreater progression (n = 5) had significantly increased BMI at 12 months,higher percentage (40%) of experienced DGF and a trend toward olderdonor age (67.6 ± 9.9 vs 56.9 ± 14.3 years; p = 0.09). The mean CAN scoreon the 6 month biopsy in this group was significantly higher (6.2 ± 1.9 vs 3.7± 2.3; p < 0.04) compared to the group with a stable creatinine, with pre-dominant histological changes on glomerular and vascular structures (cg:0.8 ± 0.45 vs 0.2 ± 0.41; p = 0.04 and cv: 1.6 ± 0.55 vs 0.73 ± 0.7; p = 0.02,respectively). Conclusion: 1 and 6 months biopsy may be valuable to deter-mine SR and BR and to prognosticate the outcome of renal allograft func-tion. The presence of delayed graft function and a progressive rise in BMIassociated with an untreated histological finding of BR and SR at 1 and 6months, might lead to a rapid impairment of the graft function acceleratingthe process of chronic allograft nephropathy.

P 087 NEPHROLOGICAL INDICATIONS IN COMBINED LIVERKIDNEY TRANSPLANTATIONG. Mosconi, M.P. Scolari, G. Feliciangeli, M. Piccari, G. Comai, D. Conte,L. Borgnino,A. Falaschini, S. Stefoni. Nephrology, Dialysis and Renal Trans-plantation Unit, S. Orsola University Hospital, Bologna, ItalyIntroduction: In isolated liver transplantation pre-transplant renal failure isa major mortality risk; there are no guidelines at the moment to establishwhen combined liver kidney transplantation (LKT) is necessary. Nephro-logical evaluation is often required to assess simultaneous kidney trans-plantation. Results: Fifteen patients (pts) underwent LKT on our Unit from1997 to 2005; twelve were on RDT and three pts with a mild or moderatechronic renal failure. We report the case of two pts who underwent LKT in2004 affected by chronic renal failure, who were not yet on RDT. At

the moment of LKT the first patient (polycystic disease) had a GFR of 29 mL/min, the second (vascular nephropathy and diabetes), had a GFR of33 mL/min. After LKT they recovered renal function without DGF: Crea-tinine (Creat.) 1,3 after 14 days and 0,9 mg/dL after 2 days respectively. Arenal scintigraphy Tc¨C99 DMSA was performed to evaluate the trans-planted kidney contribution in renal function. During follow-up in bothcases normal renal function (Creat. 1,3 mg/dL and 0,9 mg/dL) is mainly dueto the transplanted kidney. In particular in the first case the scintigraphyperformed after 9 months demonstrated a contribution of 80,5% from thetransplanted kidney, 9,1% from the right and 10,4% from the left nativekidneys. In the second case, 3 months after LKT, the functional contribu-tion resulted as 73%, 11% and 16% respectively. Discussion: The contro-versy over LKT when kidney failure does not require RDT demonstratesthat more experience is needed. In our experience it is probable that thenephron mass of the transplanted kidney is able to maintain residual renalfunction and avoids the need of hemodialysis in the early post transplantperiod. As in other combined transplantation programs (heart-kidney,kidney-pancreas), with irreversible chronic renal failure a GFR <35 m L/min(before transplant) is proposed, as could be indicated for LKT.

P 088 GENETIC FACTORS AND RISK OF ACUTE REJECTION INKIDNEY TRANSPLANTM.L. Cappuccilli, D. Conte, G. La Manna, G. Comai, G.D. Mina,L.C. Borgnino, M.P. Scolari, S. Stefoni. Institute of Nephrology, Dialysis and Renal Transplantation, S. Orsola University Hospital, Bologna, ItalyBackground/Aim: Genetic factors other than HLA have been reported tobe associated with Acute Rejection (AR), that still remains an importantcause of graft loss after renal transplantation. The purpose of the presentstudy is the identification of genotypes potentially correlated with the indi-vidual susceptibility to AR by the analysis of polymorphisms in genes codingfor cytokines and apoptosis mediators. Methods: The patients enrolled inthis study underwent kidney transplantation at the Institute of Nephrologyof the St. Orsola University Hospital of Bologna between 1998 and 2002(follow-up: 28 „b 12 months). The AR group consisted of 29 patients whoexperienced at least one AR episode, whereas the control group (non-AR)comprised of 41 kidney recipients without any rejection episode. The diag-nosis of AR was based on biochemical and clinical parameters and con-firmed by positive biopsy where possible. The two groups were comparablefor sex, age, therapy, cold ischemia time and number of HLA-DR mis-matches. Genotype analysis was performed by Restriction Fragment LengthPolymorphism for IL-10 (A-1082G, -C-819T, C-592A) and perforin (in2/C+ 645G) and Primer Extension/denaturing High-Performance Liquid Chro-matography for granzyme B (Q48R) and serine proteinase inihibitor-9 (T + 207C). By variance analysis (ANOVA and Student\’s t-test), the vari-ables that showed significant differences between AR and non-AR grouphave been identified. Results: In this investigation, the polymorphisms ofapoptosis genes do not seem to influence AR episodes. In contrast, the heterozygous genotype for IL-10/G¡V1082A polymorphism showed a sig-nificantly higher frequency in the non-AR group (p < 0.005), thus suggest-ing a potential protective role in the occurrence of AR. When consideringthe sinergistic effect of the three SNPs of IL-10 gene on the cytokine pro-duction, the high/intermediate producer genotypes was inversely correlatedwith serum creatinine levels: this data seems to indicate a positive effect ofhigh/intermediate production on graft function. Conclusions: Our resultsconfirm that genetic factors may influence the individual susceptibility toAR episodes, especially emphasizing a role of cytokine polymorphisms inthe outcome of kidney transplantation.

P 089 PRELIMINARY RESULTS OF A CLINICAL RANDOMIZEDSTUDY COMPARING CELSIOR AND HTK SOLUTIONS INKIDNEY PRESERVATION FOR TRANSPLANTATIONB. Nardo1, R. Bertelli1, E. Capocasale2, M.P. Mazzoni2, R. Montalti1,R. Dalla Valle2, N. Busi2, P. Beltempo1, L. Puviani1, V. Pacilè1, G. Fuga1,A. Faenza1. 1Department of Surgery, ICU and Transplantations, Universityof Bologna, 2Department of Surgery and Transplantation, University ofParma, ItalyBackground/Aim: A prospective, randomized, multicenter open clinical trialwas performed to compare the HTK and Celsior preserving solutions inkidney preservation. Herein, we report the preliminary data collected fromtwo Italian centers to compare the kidney postoperative function tests, themain post-operative complications and the early graft and patient survivalof liver recipients transplanted with organs preserved in CEL or HTK solu-

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tion. Methods: We analyzed the data collected from two transplant center.Twenty-one donors were randomized and the kidneys preserved with HTK(n = 15) and Celsior (n = 15) solutions and perfused in situ via aorta andportal vein. Main donors’, recipients’ and grafts’ parameters, as well askidney function tests, post-operative complications and graft and patientsurvival have been evaluated. Results: The groups were comparable withregard to donor, graft and recipient characteristics, except for the numberof HLA missmatches which is higher in HTK group and for mean dopamininfusion in the donor which is higher in Celsior group. The incidence ofAcute Tubular Necrosis (NTA) and Delayed Graft Function (DGF) inCelsior and HTK were (2 vs 2) and (0 vs 1) respectively. No differences wereobserved for acute rejection or urinary postoperative complications. The 3-month graft and patient survival rates were 80% and 86.7% in Celsior and80% and 100% in HTK. The 3-years graft and patient survival rates were80% and 86.7% in Celsior and 73.3% and 93.3% in HTK. Conclusions: Toour knowledge this is the first report comparing Celsior and HTK preser-vation solutions in clinical kidney preservation. The two solutions demon-strated similar efficacy in kidney preservation in term of early renal functionin the range of CIT considered. A definitive evaluation comparing Celsiorand HTK solutions in clinical preservation must await completion of thetrial.

P 090 COMBINED LIVER KIDNEY TRANSPLANTATION: A CASEREPORT WITH PREFORMED ANTI-HLA ANTIBODIESG. Mosconi, G. Feliciangeli, F. D’Addio, A. Zanetti, M. Piccari, S. Faenza*,G. Ercolani*, A. Faenza°, A.D. Pinna*, S. Stefoni. Nephrology, Dialysis,Renal Transplantation Unit—*Liver and Multivisceral Transplant Unit—°Renal Transplantation Surgery Unit-S.Orsola University Hospital,Bologna, ItalyIntroduction: A pre-transplant positive crossmatch is a contraindication forkidney transplantation, unlike in liver transplantation. In combined liverkidney transplantation (LKT) it is hypothesized that the liver can protectthe kidney from allograft rejection through immunological mechanisms stillnot defined. Case Report: We report the case of a 35 year-old woman witha chronic renal failure in RDT and severe gastrointestinal tract compres-sion due to a haematoma following a spontaneous liver rupture. The patientwas affected by amyloydosis and was treated with a bone marrow allo-transplantation in 2001. The liver rupture was surgically untreatable so aLKT was proposed. She had had more than 20 blood transfusions becauseof the liver rupture. The PRA was 80–100% (CDC) with specific anti-HLAantibodies (ELISA). A compatible donor regarding blood group and sizewas found. The crossmatch before transplantation was positive for B and Tcells (score 8): an emergency liver transplant was carried out. The cross-match immediately after liver reperfusion showed a diminished positivity(score 6) for T cells. After 6 hours it resulted negative for T and slightly pos-itive for B cells (4): the kidney was transplanted (ischemia time 23 h). Theimmunosuppressive therapy was: alemtuzumab, steroids, and tacrolimus.The renal function was immediately recovered with creatinine 1 mg/dL after2 days. On the 9th day a rejection episode was treated successfully byincreasing steroid therapy for 5 days (i.v. bolus). At discharge hepatic andrenal function were normal and they are still stable after 1 year. Discussion:This case showed the efficacy of LKT even in more complex immunologi-cal situations. Different mechanisms are hypothesized to explain the pro-tective role of liver on the kidney in LKT: production of HLA solubleantigens, microchimerism, preformed antibodies adsorption and immuno-modulation of T cells response. This case confirms experimental data andhighlighted in vivo and in humans that crossmatch can change from posi-tive to negative after liver transplantation and so gives highly sensitizedpatients the possibility of undergoing LKT.

P 091 A COMPARATIVE STUDY OF RENAL PRESERVATIONFOR THE PREVENTION OF ISCHEMIA/REPERFUSION INJURY:MACHINE PERFUSION VERSUS COLD STORAGE IN A PORCINEAUTOTRANSPLANT MODELD. Conte1, M.L. Cappuccilli1, G. La Manna1, B. Nardo2, L. Puviani2,P. Beltempo2, M. Piccari1, R. Bertelli2, V. Pacil2, G. Mosconi1, M.P. Scolari1,A. Faenza2, S. Stefoni1. 1Institute of Nephrology, Dialysis and Renal Trans-plantation, St. Orsola University Hospital, 2Department of Surgery andTransplantation St. Orsola University Hospital, Bologna, ItalyBackground/Aims: Different studies have demonstrated how organ preser-vation by machine perfusion is able to reduce the incidence of DelayedGraft Function, thus minimizing ischemia/reperfusion injury in kidney

transplant. In spite of this advantage, such a method of preservation is stillpoorly applied in Europe. This study was designed to compare the degreeof tissue damage after preservation by hypothermic machine perfusion orcold storage (both in Belzer solution). Methods: A total of 8 Large Whitefemale pigs comparable for weight and age underwent the following exper-imental protocol: 1) nephrectomy after warm ischemic time ranging from10 to 30 min; 2) organ preservation by hypothermic machine perfusion in 4pigs (HMP group) or cold storage in the other 4 pigs (CS group); 3) auto-transplantation of the preserved kidney with immediate contralateralnephrectomy. At each different step general parameters, histological fea-tures and ATP content per milligram of tissue (from biopsy of the preservedkidney) were evaluated. Results: The main characteristics of the two groups(HMP vs CS) are reported below. Pig weight (Kg): 28.5 ± 3.9 vs 29.3 ± 5.4;Kidney weight (g) before preservation: 111.5 ± 4.4 vs 116.2 ± 26.7; Kidneyweight (g) after preservation: 111.2 ± 5.6 vs 93.0 ± 16.9; Warm ischemia time(min): 14.2 ± 11.0 vs 14.2 ± 11.0; Cold ischemia time (hours): 14.0 ± 10.9 vs14.1 ± 10.4; Reperfusion time (min): 24.1 ± 12.0 vs 24.1 ± 12.0. In this model,a remarkable finding was the amount of ATP available to the cells afterpreservation that resulted significantly higher in HMP group than in CSgroup:ATP [mg/mg] = -15.2 ± 2.4 (HMP) vs -73.1 ± 1.7 (CS), p = 0.007. Con-clusions: The present model suggests that organ preservation by machineperfusion is able to lessen cellular impairment in comparison with coldstorage. According to our data, machine perfusion may help to preventischemia/reperfusion injury and to control microstructural damage in transplantation.

P 092 THE FIRST CASE OF URETERAL DUPLICATION IN ACOMBINED LIVER-KIDNEY TRANSPLANTATIONB. Nardo1, R. Montalti1, V. Pacilè1, R. Bertelli1 P. Beltempo1, G. Cavallari1,L. Puviani1, M. Licursi1, S. Stefoni2, A. Cavallari1, A. Faenza1. 1Departmentof Surgery, ICU and Transplantations, 2Nefrology, Dialysis and Transplanta-tion Unit, University of Bologna, ItalyBackground/Aim: Kidneys transplantation with ureteral duplication mayrepresent a doubled risk factor in terms of ureteral stenosis or necrosis withurinary leakage usually from the site of ureteroneocystostomy. The inci-dence of complete duplication appears very low being 0.19%. We report theuse a kidney with ureteral duplication in the specific setting of multiorgantransplantation since it could be considered a adjunctive risk factor for uro-logical complications. Methods: The recipient was a 67-year-old man, suf-fering from a terminal renal insufficiency. He was also affected by cirrhosisHCV-related. The patient was waiting the combined transplantation for 27months and in the last two months his hepatic function dramatically wors-ened. The donor was a 53-old-year man who died of non-traumatic sub-aracnoid haemorrhage. A good HLA compatibility was observed betweendonor and recipient. During harvest both kidneys presented a completeureteral duplication. So the ureters were freed together with a wide cuff ofperiureteral tissue and dissected distally. No vascular abnormalities werenoted during the removal of both kidneys. The grafts were flushed with Uni-versity of Wisconsin solution and stored in the same solution. Results: Theliver was reperfused after 9 hours of cold ischaemia. Subsequently thekidney was vascularized after 15 hours of cold ischaemia. Urine productionoccurred immediately after revascularization. Two separated uretero-neocystostomies with a single antireflux technique were performed.Cyclosporine and steroids were given. Post-operative course was unevent-ful and liver and kidney function were normal. The 7-day cystography was normal. The 6, 12, 24 months ultrasonography showed no signs ofhydronephrosis or hydroureter. After 28 months a renal cancer was diag-nosed and the patient underwent a right nephrectomy. The liver-kidneyrecipient had an excellent hepatic and renal function for 84,7 months. Hedied of malignancy from de novo tumor. Conclusions: On the basis of thisexperience a kidney with an ureteral duplication, while rare, can be satis-factory used also in the combined liver-kidney transplantation.

Artificial Liver

P 093 MARS AS REPLACEMENT THERAPY OF THE LIVERDETOXIFYING FUNCTION IN ACUTE ON CHRONIC LIVERFAILURER. Marangoni, L. Unit, S. Giuseppe. Hospital, Milan, ItalyBackground: The efficacy of MARS (Molecular Adsorbent RecirculatingSystem) as replacement therapy of the liver detoxifying function has alreadybeen reported in the literature. Methods: Based on these findings 10 patients

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affected by acute on chronic liver failure (4 affected by chronic hepatitis C,4 by primary biliary cirrhosis, 1 by autoimmune cholangitis, 1 by primarycirrhosis) have been treated by MARS. Together with other clinical signs,the patients lamented severe pruritus, refractory to pharmacological therapyand showed scratching skin lesions. MARS treatment has been performedwith the following modalities: 4 sessions in 4 consecutive days; session time:6 hours; blood flow: 200 ml/min; albumin flow: 200 ml/min; dialysate flow (inthe albumin dialyzer): 500 ml/min; heparin 750 U/hour (on the average); nobody weight loss, because no patient showed fluid overload and renal failure.At the beginning and at the end of each session have been determined:bilirubin, bile acids, cholinesterase, alkaline phosphatase, ammonia, pro-thrombin activity,AST,ALT, GGTP. Results: After the cycle of MARS treat-ment the following statistically significant differences have been observed:decrease of bilirubin (p £ 0.00001), bile acids (p £ 0.00001), ammonia (p £0.0001), alkaline phosphatase (p £ 0.002); increase of cholinesterase (p £0.0001) and prothrombin activity (p £ 0.002); no change of AST, ALT andGGPT; disappearance of the severe pruritus after the third MARS treat-ment. It is deserving of pointing out that at the end of each session biliru-bin, bile acids and ammonia plasma levels showed significant decrease incomparison with the starting values. One month after the end of the treat-ment cycle blood parameters appeared unchanged in 8 patients and slightlymodified in 2, clinical conditions were satisfactory, pruritus was still absentand the scratching lesions were on the way of recovery. Conclusion: Theseresults confirm that MARS is a very efficient method in the replacement ofthe liver detoxifying function.

P 094 MODIFICATION OF TNF-a AND IL-6 IN PATIENTSTREATED WITH MOLECULAR ADSORBENT RECYCLINGSYSTEM (MARS)G. Ambrosino, A. Naso, U. Cillo, S. Basso, P. Feltracco, P. Carraro, G. Zanus,A. Brolese, M. Plebani, G.P. Giron, D. D’Amico. University of Padova,Padova ItalyAim: The goal of the study has been to evaluated the cytochines TNF-aAND IL-6, variations and their clinical significance in patients with acuteon chronic liver decompensation treated by MARS. Patients and Methods:Seventeen patients (aged between 18 and 60) with acute on chronic liverdiseases (cirrhosis) were treated by MARS (TERAKLIN, Germany). Allpatients were in a transplant waiting list. The diagnosis was based on thestandard examinations previewed by the National Protocol. The indicationsto MARS treatment were: bilirubine > 250 mm/L, encephalopathy (HE)stage II-III, Serum creatinine (crs), >1.5 mg/dl. Patients with sespsis, preg-nancy, severe coagulopathy, were excluded. MARS treatment has consistedin 3 consecutive days treatment (6 hours each one) followed by 3 treatmentone on the other day. Before, during and after treatment, IL-6, Tnf-a,Bilirubin, liver function tests and renal tests were measured. Blood pressurewas taken 3 times during treatments. The neurological status was verifiedbefore and after each treatment. Results: IL-6 increased during each treat-ment while TNF-a significant decreased (T Test—p < 0.001). This result wasmore evident in the first 3 days (continuos treatment), while during treat-ment in the alternative days, IL-6 was not significant high. Bilirubin signif-icant decreased (Pre treatment 560 ± 159 mmo/L range 340–720; postTreatment 421 ± 197.98 (range 290–607), Creatinine decreased respect tothe pre treatment value (p < 0.01). Encephalopathy passed from stage IIIto stage II. Blood pressure was stable during treatment (120/70 mm Hg ±15). Four patients died for MOF. All of these patients were out of the pro-tocol and treated by compassion scope. Il-6 and TNF-a had a controversialanswer: Il-6 increased in 1 patient while did not increased in the other 3.TNF-a increased in all 4 patients and never decreased. Severe pruritus disappear in 3 patients (biliary cirrhosis) after 5 treatments. Discussion:These results are evident because liver failure is a clinical syndrome thatresults from loss functional liver cell mass below a critical level. Cytochinesplay a crucial role in liver diseases, and the monitoring of their levels may be an usefulness indicator of response to treatment. Conclusion:MARS seems to be safe and useful and our brief experience suggest its useon these kind of patients. The mortality can be high if the indications arewrong and patient is already in an non recoverable (end-stage disease)status. Detoxification is an important action to promote and favouring liverregeneration, but liver should have a sufficient reservoir to respond to theinjuries.

P 095 A NEW MATHEMATICAL MODEL FOR BILIRUBIN KINET-ICS DURING MARS SESSIONSE. Magosso1, M. Ursino1, L. Colì2, L. Bolondi3, S. Stefoni2. 1Dept. of Elec-tronics, Computer Science and Systems, 2Nephrology, Dialysis and Trans-plantation Unit, 3Liver Unit, Division of Internal Medicine, University ofBologna, ItalyBackground: MARS (molecular absorbent recirculating system) representsone of the most promising techniques for extracorporeal liver replacement.In this system, a fixed volume of albumin circulates in a closed loop circuit,receiving toxins from blood. Albumin dialysis using MARS has been exten-sively investigated in a number of clinical studies. However, a quantitativedescription of its depurative capacity is still lacking. Aim of this work is topresent a mathematical model of bilirubin kinetics during MARS dialysisand to validate this model on real data measured during clinical sessions.Methods: The model includes four compartments: two for the patient,describing the intracellular and extracellular pools, and two for the albuminextracorporeal circuit. Equations in each compartment represent masspreservation, mass exchange between compartments, and kinetic of biliru-bin-albumin chemical reactions. Measurements have been performed on 8sessions in 5 patients. For each session, bilirubin concentration has beenmeasured every hour in blood and at two points (before and after the adsor-bent columns) in the albumin circuit. Results: Simulation results demon-strate that the model is able to simulate bilirubin kinetic in blood and in the albumin extracorporeal circuit quite well (SD of error in blood =1.53 mg/dL) by using a single set of parameters for all trials. The accuracyfurther improves (SD = 0.98 mg/dL) if three parameters characterizing thedepurative efficacy of the circuit are individually estimated in each session.These parameters represent the dialysance of the filter, and the initial andfinal clearance of the adsorbent columns. Conclusions: The present studyrepresents the first attempt to describe bilirubin kinetics during MARS ses-sions using a multicompartmental model. Results suggest that the modelcan be used “a priori”, (i.e. using a single set of parameters) to achieve asatisfactory prediction of bilirubin depuration. The possibility to achieve “aposteriori” estimation of a few parameters of the system may be exploited,in future works, to investigate the dependence of these parameters on theoperative conditions and/or on patient individual state, thus arriving attreatment optimization.

P 096 ALBUMIN LIVER DIALYSIS (MARS)—TREATMENT INACUTE ACETAMINOPHEN POISONINGSP. Hydzik, T. Gawlikowski, K. Ciszowski, J. Pach. Clinical ToxicologyDepartment, Jagiellonian University Medical Collage, Kraków, PolandBackground/Aim: From the toxicology point of view late N-acetyl-cysteine(NAC) administration in acute acetaminophen intoxications (more than 15hours post-ingestion), does not prevent liver injury. In the same way serumacetaminophen concentration is not sufficient to determinate hepatotoxiceffect (Rumack-Mathew nomogram). No reliable and useable early criteriaare known to indications for albumin liver dialysis (MARS). Most often weused King’s College of London Criteria (due to acetaminophen) or Clichycriteria. Those criteria were build to indicate most severe poisoned patientswith acute liver failure who will not survive without liver transplantation.Methods: We present a series of 5 cases of acute late acetaminophen poi-sonings occurred in young patients (mean age 28 years). All patient haveingested hepatotoxic acetaminophen dose (mean dose 18.8 grams). Themean time from ingestion of acetaminophen to the hospital admission was50 hours and mean serum acetaminophen level in 4 cases was 101.26 mg/l.In one case no plasma acetaminophen level was founded during admission.All patients were considered for MARS treatment, especially with regardto encephalopathy signs (Io/IIo according West Haven criteria), jaundice,prothrombin time and factor V. Before concrete application and use of theMARS therapy we avoid administration of fresh frozen plasma (FFP), toeliminate masking the clinical signs of the synthetic liver dysfunction. Insevere coagulopathy, MARS therapy was performed without need of anti-coagulation (systemic heparin). Results: In every case the only one, 8 hoursduration therapy was performed. The full recovery with improving patientsgeneral status and with normalization of the liver function was observed.MARS therapy effectively decreased plasma ammonia level with improve-ment encephalopathy degree, decrease plasma total bilirubin level andprobably stimulated prothrombin synthesis. Conclusion(s): There are stillfew data in MARS therapy in patients with acute acetaminophen intoxica-tions leading to acute liver failure. The place of MARS should be furtherexplored. Our experience indicate to applied MARS therapy much more

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earlier, before the patient will fulfil all requirements which are useful in livertransplantology.

P 097 ECONOMIC EVALUATION AND SURVIVAL ANALYSIS OF THE LIVER DIALYSIS SYSTEM MARS IN PATIENTS WITHALCOHOLIC LIVER DISEASEF. Hessel1, S. Mitzner2, J. Wasem1. 1Institute for Health Care Management,University of Essen, 2Department of Nephrology, University of Rostock,GermanyObjective: of this study was to determine survival, costs and cost-effective-ness of the artificial liver support system MARS in patients with acute-on-chronic liver failure and an underlying alcoholic liver disease. Methods: All13 patients treated with MARS at Rostock University Hospital from 1999to 2001 were compared to 23 controls controlling for age, sex, length andseverity of disease. Inpatient hospital cost data were extracted frompatients’ files and hospital’s internal costing. During the two year follow uppatients and treating GPs were contacted to collect data about medicaloutcome, resource use and survival. Results: Mean two year survival timein MARS group was 511d, 263d in controls. Kaplan-Meier analysis showsadvantages of MARS-patients but no significant difference (Logrank: p =0.11). Direct medical costs per patient from a perspective of the Germanhealth care system were 33,634EUR for MARS-patients and 8,520EUR forcontrols. There was no difference in health related quality of life (EQ-5Dand SF 12). The incremental costs per life-year gained were 37,064EURwithin a time horizon of 2 years. Modelling long time costs and survival overa 20 years period based on the empirical data of the study there is a lessthan 5% survival probability and costs per life year gained of 13.000 EUR.Conclusion: The trade-off between medical benefit and higher costs has to be made, but already after two years an acceptable cost-effectiveness of MARS can be observed. Prolonging the time horizon improves cost-effectiveness-ratios.

P 098 ACUTE LIVER FAILURE: FRACTIONATED PLASMA SEP-ARATION/ADSORPTION (FPSA) AND HIGH-FLUX HEMODIALY-SIS (HD)-BRIDGING THERAPY TO LTXG. Junge, S. Kohler, L. Schewior, I. Sauer, A. Pascher, P. Neuhaus. Trans-plantationschirurgie Charite-Berlin—GERMANYBackground/Aim: Evaluate safety, tolerability and efficacy of FPSA/HD inbridging management of pts diagnosed with ALF which is characterized byaccumulation of both water-soluble and poorly water-soluble toxins. Theaccumulation is believed to be responsible for the development of associ-ated end-organ dysfunctions (kidney, circulation, brain). FPSA/HD sepa-rates removal of poorly water-soluble (albumin-bound) and water-solubletoxins into two modules: an upstream fractionated plasma separation andadsorption (FPSA) circuit for poorly water-soluble toxins and a down-stream high-flux hemodialysis for water-soluble toxins. Methods: 25male/female patients with ALF listed for high urgency LTx were enrolledto treatment group and subsequently in a 1 : 1 randomization compared tostandard medical procedure in a total of 50 patients. Group A (n = 25)received standard medical treatment plus FPSA/HD. Group B (n = 25)received standard medical therapy. FPSA/HD was given at day 1, 2, 3, 5 oruntil LTx for a maximum of 8 days. Inclusion criteria were age > 18 years,MELD-Score > 30 with a diagnosis of drug/chemical, poison, viral, or idio-pathic ALF. Results: Entry demographic, etiology, and laboratory informa-tion were not different between the 2 groups. MELD-Score in all pts wasabove the normal cut-off of 40 (mean 44). Pts survival at POD 5 was 90%in group A. Mean duration of therapy was 3 courses of 6.5 hrs. Meanammonia pre/post FPSA/HD was 145 vs. 62 mmol/l (max. 289 mmol/l); meanBilirubin 28.2 vs. 12.4 mg/dl (max. 46.4 mg/dl); BUN 145 vs. 48 mg/dl (max.260 mg/dl); Kreatinin 3.8 vs. 1.4 mg/dl (max. 6.1 mg/dl); initial ICG plasmadisappearance rate (PDR) was 5.6%/min, 15 min retention (R15) was44.4%; at POD 5 PDR was 16.1%/min and R15 17.0%. Mean norepineph-rine/h pre/post FPSA/HD was 1.2 mg/h vs. 0.2 mg/h and need for mechani-cal ventilation was 100 vs. 30%. Moreover FPSA/HD has proven to behighly biocompatible, so there was no activation, as platelet counts and clot-ting factors remained unchanged. Conclusion: The data suggests that theprincipal effect of FPSA/HD therapy was to allow patients with ALF tosurvive while awaiting LTx. The transplant related death rate was signifi-cant lower in Group A.

P 099 BIOLOGICAL CHARACTERISTICS OF IMMORTALIZEDHUMAN HEPATOCYTE (HepLL) AFTER TRANSPLANTATION INSPLEEN OF BALB/c NAKED MICEL.L. Li, Y.M. Zhang, J. Li, G.P. Sheng, H.Y. Yu. Department of InfectiousDisease, The First Affiliated Hospital, College of Medicine, Zhejiang Uni-versity, Hangzhou, Zhejiang, P.R. ChinaAim: To investigate the biological characteristics of new established immor-talized human hepatocyte (In our previous study, it was established by trans-ferring Simian Virus 40 large T (SV40LTag) into hepatocytes isolated fromthe liver of a normal male donor. After culture and selection, one resultinghepatocyte line which showed the immortalized characteristics in vitro andmaintained highly differentiated liver function with the morphological char-acteristics of normal human hepatocyte was named as HepLL.) After trans-plantation in the spleen of BALB/c naked mice. Method: BALB/c nakedmice were randomly divided into two groups. HepLL cells were transplantedinto the spleen of mice in group A with left liver lobe resected while mice ingroup B received the same amount of HepLL cells without the removal of left liver lobe. 1, 3, 7, 15 and 30 days after transplantation, spleens wereexamined by the methods of pathology and immunohistochemistry to studythe distribution and prolification (Ki-67, a represented mark of prolificationwas determined ) of HepLL cells in the spleen. Expression of glycogen,AFP and HEP (a kind of specific marker of hepatocytes) were detected.Meanwhile, heart, liver, lung, kidney and omentum were examined by HEand immunohistochemical method (HEP was detected) to determine themigration of human-derived hepatocytes. Results: HepLL cells could survivefor more than 30 days after transplantation. They proliferated and expressedHEP, restored glycogen, without the expression of AFP. After transplanta-tion of days 30, the prolification ability of HepLL transplanted in spleen is stronger in group which left liver lobe was resected then in group which it wasn’t resected. HepLL cells, which were transplanted into the spleen,could migrate and integrate into the host liver, and then proliferated in theliver for a long time. Conclusion: HepLL cells transplanted into spleen canmaintain their biological characteristics in vivo while they migrate into theparenchyma of host liver. Resection of the left liver lobe created beneficialmicroenvironment for the proliferation of HepLL cells.

P 100 THREE DIMENSIONAL CELL CULTURE IMPROVES SYN-THETIC ACTIVITY OF HEPG2 CELLS IN VITROA. Kinasiewicz, E. Banasiuk, J. Kawiak, A. Weryñski. Institute of Biocy-bernetics and Biomedical Engineering, Polish Academy of Sciences,Warsaw,PolandCurrently, there is no ideal cell source for bioartificial liver device. Numberof primary human hepatocytes is limited. Animal cells are suspected toimmunize recipient and to transmit some viruses (PERV). The aim of ourstudy was to assess the influence of culture conditions of hepatocyte cell line(human hepatoma cell line, HepG2) on their metabolic activity. Cells werecultured in standard plates as monolayer and in the Martigel as a 3D culturemodel. Albumin synthesis, urea production, glucose concentration inmedium were measured during the experiment. Lidocaine was used toassess detoxification activity of HepG2 cells. Lidocaine and MEGX (mainLidocaine metabolite) were measured with HPLC. Albumin synthesis wassignificantly higher in Matrigel than in monolayer culture. 3D culture inMatrigel improved urea production by HepG2 cells (2,70 ± 0,27 vs. 1,53 ±0,28 mg/dL/24 h; n = 5; p < 0,05). The detoxification experiments revealedthat HepG2 cells do not metabolize lidocaine neither in monolayer nor in3D culture.

Our experiments indicated that 3D culture significantly improves meta-bolic activity (albumin and urea synthesis) of human hepatoma cells(HepG2). Because of unlimited proliferation capacity these cells can beobtained in high amounts. 3D culture does not influence detoxification activity connected with CYP450. HepG2 cells are able to produce highamounts of albumin and can function as a protein source in bioartificial liver.

P 101 EVALUATION OF A HYBRID ARTIFICIAL LIVERMODULE WITH A HEPATOCYTES ORGANOIDH. Mizumoto1, K. Aoki1, K. Ishihara1, K. Noda1, K. Nakazawa2,T. Kajiwara1,K. Funatsu1. 1Dept. of Chem. Eng., Kyushu Univ., 2Dept. of ChemicalProcesses and Environments, The Univ. of Kitakyushu, f*ckuoka, JapanAim: As a new hybrid artificial liver (HAL), we developed a HAL moduleincluding hepatocyte organoids that formed outside of hollow fibersarranged regularly in the module. The efficacy of our HAL was evaluatedby applying to the liver failure rat. Methods: We developed a module equip-

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ping many hollow fibers arranged regularly. 3.0 ¥ 108 rat hepatocytes wereimmobilized outside of hollow fibers by centrifugal force to induce forma-tion of hepatocytes organoid. For animal experiments, we designed a wholeblood extracorporeal circulation system including this module. The modulewas applied for 1 hour to a rat with liver failure induced by a two-thirdpartial hepatectomy and temporary hepatic ischemia (HAL group). Thesame system without hepatocytes in the module was also applied to ahepatic failure rat as control group. Results: The ratio of spontaneous recov-ery in this liver failure model was 80%. In the animal experiments, bloodammonia rapidly increased in the control group. All rats died in the middleof treatment or immediately after treatment in control group. On the otherhand, in the HAL group, the increase of blood ammonia was completelysuppressed. Liver weight increased and reached to normal level. In conse-quence, all rats completely recovered. Conclusion: These results indicatedthat our HAL had potential functions not only to selectively metabolizeaccumulated injurious substances, but also to supply necessary factors forthe recovery of a damaged liver and body.

P 102 DEVELOPMENT OF A NOVEL HYBRID ARTIFICIALLIVER WITH ORGANOID-SHEETT. Kusumi1, K. Ishihara1, H. Mizumoto1, K. Nakazawa2, T. Kajiwara1,K. Funatsu1. 1Dept. of Chem. Eng., Kyushu Univ., f*ckuoka, 2Dept. of Chemical Processes and Environment, The Univ. of Kitakyushu,Kitakyushu, JapanAim: For the development of a hybrid artificial liver, an organoid formationtechnique in vitro may be required to express high liver-specific functionsfor long term. Moreover, it is equally important to control the thickness ofan organoid physically because a dead cell layer due to oxygen exhaustionwill be generated inside the organoid of more thickness than 100 mm. Tosatisfy these requirements, we have developed a novel hybrid artificial liverwith sheet-shaped organoid (organoid-sheet). Methods: We designed amodule which consisted of medium flow channels and cell filling spaces.Each space was separated by porous flat membranes and was piled up byturns. The thickness of each space was controlled less than 100 mm by spacer.7.0 ¥ 107 rat hepatocytes were immobilized in the module, which was per-fused with 10.7 ml/min medium flow rate. Cell viability, histological analy-sis, and liver-specific functions were evaluated. Results: Cell viability washighly maintained in the organoid-sheet controlled less than 100 mm inthickness, where a dead cell layer was not observed during culture period.The module achieved high cell density of 4.5 ¥ 107 cells/cm3—module andexpressed high liver-specific functions, such as ammonia removal andalbumin secretion. Conclusions: Our results showed that this novel modulewith organoid-sheet might be effective to develop a hybrid artificial liver.

P 103 EVALUATION OF A BIOARTIFICIAL LIVER BASED ONNONWOVEN FABRIC BIOREACTOR WITH PORCINE HEPATO-CYTES IN FULMINANT HEPATIC FAILURE PIGSL. Li, W. Du, Y. Zhang, J. Li, X. Pan, J. Chen, H. Cao, Y. Chen, Y. Chen. KeyLaboratory of Infectious Diseases, Ministry of Health, Department of Infec-tious Diseases, the First Affiliated Hospital, Zhejiang University School ofMedicine, Zhejiang, ChinaBackground/Aims: Fulminant hepatic failure (FHF) is associated with ahigh mortality rate in the absence of orthotopic liver transplantation. Abioartifical liver (BAL) device may improve survival by bridging patients toliver transplantation or to regeneration of their own livers. We currentlydeveloped a novel BAL system based on a nonwoven fabric bioreactor con-taining porcine hepatocytes. In this study, we investigated the efficacy of ourBAL system in pigs with FHF as a preclinical test. Materials and Methods:The porcine FHF model was induced with intravenous administration of D-galactosamine at a dose of 1.25 g/kg body weight. Eighteen hours after D-galactosamine injection, ten FHF pigs were divided randomly into: (1) aBAL group (n = 5), in which pigs received BAL treatment with 1.2 to 1.5–109

hepatocytes for a duration of 6 hours and (2) a control group (n = 5), inwhich pigs received BAL treatment without hepatocytes. Parametersrelated to liver function and animal survival up to 168 h were determined.Results: In the BAL group, blood ammonia and plasma lactate levels werelower, and serum glucose levels and Fischer index were higher than thosein the control group. The survival time of FHF pigs in the BAL group wassignificantly prolonged (96 ± 27 h) compared with the control group (53 ±14 h). Conclusions: The BAL system based on nonwoven fabric bioreactorcontaining porcine hepatocytes appears to be effective in treatment of FHFin pigs.

Organ Transplantation 2

P 104 PERIPHERAL NERVE REGENERATION USING A POLYG-LYCOIC ACID-COLLAGEN TUBE, COMPARISON WITH AN AUTOGRAFTS. Itoi, K. Endo, Y. Inada, S. f*ckuda, A. Nakada, S. Ichihara, T. Nakamura.Department of Bioartificial Organs, Institute for Frontier Medical Sciences,Kyoto University, Kyoto, JapanBackground/Aim: We have developed a bioabsorbable polyglycolic acid(PGA) tube filled with collagen sponge (PGA-collagen tube) as a nerveconnective guide. The aim of this study was to compare its effectiveness withthat of an autograft in terms of nerve regeneration across a gap. Methods:The PGA-collagen tube was implanted into 24 male Wistar rats across a 10-mm gap in the left sciatic nerve. The right sciatic nerve was reconstructedwith the autograft harvested from the left side, as a control. Results: Elec-trophysiological studies reveal the tendency that functional nerve recoveryafter reconstruction with a PGA-collagen tube was faster when comparedwith nerve reconstruction using an autograft. However for up to 12 weekspost surgery there are no differences between PGA-collagen tube side andautograft side. Histologically, axonal regeneration after reconstruction withautograft was faster when compared with nerve reconstruction using aPGA-collagen tube. At four weeks postoperatively, axonal regenerationoccurs only in autograft side but not in PGA-collagen tube side. The myeli-nated axons on the PGA side were larger in diameter and in count thanthose on the autograft side. Conclusion: The PGA-collagen tube has thepotential to be an effective alternative to conventional autografting for therepair of some peripheral nerve defects, though there are unexpected dis-crepancies between electrophysiological and histological findings.

P 105 EPILEPSY STOP MACHINET. Yambe1, S. Maruyama2, E. Asano3. 1Institute of Development, Aging &Cancer, Tohoku University, Sendai, 2Institute of Fluid Science, Tohoku Uni-versity, Sendai, Japan, 3Children’s Hospital of Michigan, Detroit, MI, USA0.5–1% of the general population have the epilepsy (NIH Consensus Panel,1990). Seizures cannot be controlled by medications in 20% of epilepsypatients. A third of these patients need the surgical resection of epilepticfocus for the control of the attacks. However, surgical resection of a part ofbrain have a risk of complications. There is a patient who feels a sign beforethe convulsions of epilepsy. When feeling a sign, there is a treatment, whichperforms a vagal nerve stimulus. However, a stimulus of a vagal nerve is nota trustworthy treatment. We had invented the method of cerebral partialcooling and applied for the patent (2004-304964). By this method, if apatient feels the sign of the attack of epilepsy, a switch will be pushed.Control switch was implanted under the skin. By switch on, the focus ofepilepsy is cooled and a convulsion attack is prevented beforehand. Abattery is used in a patient with few attacks. Transcutaneous energy trans-mission system (TETS) is used in a patient with a frequent attack. In thissystem, if a patient feels a sign, TETS will be used. Outer coil will beattached to the inner coil under the skin. Energy is supplied and a focus iscooled. Now, we are studying the prediction algorithm of epilepsy. If pre-diction is possible, the automatic control of epilepsy will become possible.It is expected that it becomes good news for the patient of epilepsy.

P 106 DEVELOPMENT OF MOVING ESOPHAGEAL STENTUSING ARTIFICIAL PERISTALTIC MOTIONK. Sekine1, T. Yambe1, Y. Saijo1, Y. Shiraishi1, Y. Hori2, M. Watanabe1,Q. Wang1, H.J. Liu1, H. Matsuki3, F. Satoh3, T. Maeda 4, D. Honma4, S. Nitta1.1Institute of Development, Aging and Cancer, Tohoku University, Sendai,2Biomedical Engineering Research Organization, Tohoku University,Sendai, 3Department of Electrical and Communication Engineering, Grad-uate School of Engineering, Tohoku University, Sendai, 4Toki Corporations,Tokyo, JapanBackground: For patients of esophageal cancer, the lost of such functioncause the low quality of life. To solve this problem, we have studied aboutan artificial peristaltic motion using helicoidal shape memory alloy (SMA).At this paper we have developed a moving esophageal stent using SMA tosupport drinking. Methods: A shape memory alloy (SMA) was used as aartificial muscles around the biogenic esophagus pipe to make the peristal-sis. We use a special SMA, Bio Metal Helix 150 (BMX150; Toki Corpora-tion, Tokyo, Japan). BMX150 has a high potential characteristics of amaximum systole-diastole ratio about 200% and at the maximum systolicforce of 0.4 N. Outer side of the pipe was covered by Ni-Ti made stent and

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fixed to the pipe. The moving esophageal stent was inserted into the esoph-agus of the goat and observed the behavior in endoscope. Results and Con-clusion: The moving esophageal stent could have shown good performancesas a peristalsis device in vivo. But, farther investigation, e.g. artificial occlu-sion, or biocompatible esophagus canal, should be needed for the develop-ment of artificial esophagus device.

P 107 A MODEL OF THE SWEAT SECRETION FROM A SWEATGLANDP. Foltynski, P. Ladyzynski, K. Migalska-Musial, J.M. Wojcicki. Institute ofBiocybernetics and Biomedical Engineering, Polish Academy of Sciences,Warsaw, PolandAim: There are some commercially available methods of monitoring ofsweat secretion from a skin (average measurements), but there is only oneimplemented method of monitoring of a single sweat gland activity. Thismethod is based on measurement of electric conductivity of perfusion solu-tion flowing over the outlet of sweat gland. In order to verify the responseof the measurement system to secretion of fixed sweat amount it was nec-essary to develop a model of sweat gland secretion. Methods: The modelconsists of metal-acrylic body, rod with pit, coupler, photo-barrier and step-ping motor with computer interface. The model is controlled by a PC com-puter via parallel port. The NaCl water solution (10 mmol/L) was usedinstead of sweat. The model delivers fixed amount of sweat solution in eachworking cycle. Results: First trials with the model reveled that response ofthe measurement system depended on placement of the probe over thesweat solution outlet of the model. Next trials reveled that proper perfu-sion solution mixing with sweat was crucial in getting maximal outputresponse. Other experiments showed that the response shape to excretionof the same amount of sweat was depending on its ejection intensity. Con-clusions: The developed model of the sweat secretion from sweat glandenabled quality analysis of the newly developed measurement system. Mea-surements of the sweat secretion from the single sweat gland could bringnew diagnostic information as well as could be used during monitoring ofefficiency of the applied therapy.

P 108 A TNFa POLYMORPHISM MAY BE INVOLVED IN THEPROGRESSION OF HCV-RELATED CHRONIC LIVER DISEASEAND IN HEPATOCELLULAR CARCINOMA DEVELOPMENTV. Cerreta1, L. Gramantieri2, R. Giannini2, S. Bondini2, R. Righini1,P. Chieco1, L. Bolondi2. 1Centro di Ricerca Biomedica Applicata (CRBA),2Dipartimanto di Medicina Interna e Gastroenterologia, Bologna, ItalyBackground: In recent years, it has been shown that variants of genes encod-ing immunoregulatory proteins may contribute to the overall variability ofliver diseases progression. It is questioned if the inappropriate ratio of pro-inflammatory and anti-inflammatory cytokines may determine differentoutcomes. Since polymorphisms within cytokine genes play a role incytokine production, the aim of our study was to ascertain if genetic poly-morphisms in different citokines may be associated with a different pro-gression of HCV-related chronic liver disease. Methods: Genomic DNAfrom 162 patients (81 males, 81 females) sharing the same ethnic back-ground was studied by Single Base primer Extension (SBE) combined withDenaturing High Performance Liquid Chromatography (DHPLC). Patientswith HCV-related chronic liver disease enrolled into the study included 71chronic hepatitis, 34 liver cirrhosis without hepatocellular carcinoma (HCC)and 57 cirrhosis with HCC. The mean age of patients with chronic hepati-tis was similar to that of patients with cirrhosis, with and without HCC (71years). Eight polymorphisms were analyzed: IL1b + 3953, TNFa-308 and -238, IL10-1082, -819 and -592, TGF1b-800 and IL6-174. Allele frequencieswere compared for liver cirrhosis vs. chronic hepatitis; liver cirrhosis withHCC vs. patients without HCC; and with respect to the sex. Results: TheTNFa-308GG genotype occurred significantly more often in cirrhoticpatients with HCC (n = 57) than in cirrhotic patients without HCC (n = 34),(OR 5.5 p = 0.004). In our series it was observed that 60.4% of males and39.6% of females were cirrhotic (n = 91), (p = 0.003). Females with cirrho-sis and HCC (n = 36) more frequently had the IL10-592CC genotype ascompared with patients with chronic hepatitis (n = 45), (OR 4.1 p = 0.002).No associations were observed between the other polymorphisms analyzedand the outcome of liver disease. Conclusions: These data suggest thatTNFa-308GG genotype is associated with HCC development in patientswith HCV-related liver cirrhosis. Moreover, female patients with IL10-592CC genotype showed a higher susceptibility to progression to liver cir-rhosis and HCC development.

P 109 IMPACT OF CYTOKINES AND APOPTOSIS MOLECULESPOLYMORPHISMS ON CHRONIC ALLOGRAFT NEPHROPATHYN. Lanci, M.L. Cappuccilli, G. La Manna, G. Comai, M. Ortolani, F. Bianchi,L.C. Borgnino, M.P. Scolari, S. Stefoni. Institute of Nephrology, Dialysis andRenal Transplantation, S. Orsola University Hospital, Bologna, ItalyBackground/Aim: Chronic Allograft Nephropathy (CAN) is the main causeof long-term kidney graft loss. The objective of our work is the identifica-tion of genetic risk profiles for CAN by studying the influence of polymor-phisms in genes coding for cytokines (IL-6 and TGF-£]) and apoptosismediators (Fas, Granzyme B and Serine Proteinase Inihibitor member 9).Methods: The study included 158 kidney recipients transplanted at ourcentre between 1997 and 2003 (follow-up: 28 ,,b 12 months), 30 of them withCAN (CAN group) and 128 with long-term stable graft function (no-CANgroup). The diagnosis of CAN was based on clinical, biochemical and his-tological criteria according to information derived from literature. Thepatients in the two groups were matched for sex, donor and recipient age,HLA-mismatches, cold ischemia time and therapy. The patients were geno-typed by RFLP (Restriction Fragment Length Polymorphism), PrimerExtension/denaturing High-Performance Liquid Chromatography anddirect sequencing. Differences between continuous variables were evalu-ated by two-tailed Student\’s t-test and by ANOVA. To estimate the risk ofCAN associated with gene variants, odds ratios were calculated by multipleregression analysis. Results: In our population of kidney allografts, theminumum serum creatinine level achieved (not sporadically) after trans-plantation was significantly higher in CAN group than in no-CAN group(1.50¡Ó0.44 mg/dl vs 1.31¡Ó0.30 mg/dl, p < 0.005), thus confirming the pre-dictive role of such a parameter. Moreover, certain combinations of Fas andIL-6 gene polymorphisms seem to have a protective effect against CAN.Eighteen patients of the no-CAN group typed as IL-6/-174 GG and Fas/-670 GG, whereas this allelic association was never found in patients affectedby CAN. Multivariate analysis showed a 0.79-fold reduced risk of CAN inthe carriers of this combination in comparison to other genotypes (OR =0.79; 95% C.I. = 0.72–0.86). Conclusions: The study points out the role ofgene polymorphisms as predictors of CAN after kidney transplantation.Larger prospective studies are needed to clearly define the potential bene-fits of genotyping in the risk stratification and in the optimization of thera-peutic and immunosuppressive interventions.

P 110 ANGIOTENSIN II HAS GENOTOXIC IMPACT ON HUMAN(HK-2) AND ANIMAL (LLC-PK1) KIDNEY CELLS BUT NOT ONHUMAN (HL60) OR MOUSE (L5178Y) LYMPHOMA CELLSP. Rutkowski1, N. Schupp1, U. Lakner1, J. Vienken2, A. Heidland3,H. Stopper1. 1Institute for Toxicology and Pharmacology, University ofWuerzburg, Germany, 2Fresenius Medical Care Bad Homburg, 3Departmentof Internal Medicine, University of Wuerzburg, GermanyBackground/Aim: Angiotensin II (ANG II) is a potent vasoconstrictoryhormone and exerts proinflammatory and oxidative effects. It plays a fun-damental role in the development of renal insufficiency, atherosclerosis andcongestive heart failure. The ANG II-induced oxidative stress is caused byactivating NADPH-oxidase via the AT1 receptor. Oxidative stress is animportant factor of genomic damage and may lead to deleterious conse-quences, including atherosclerosis and cancer development. The aim of thisstudy was to elucidate the impact of ANG II on the genomic integrity ofkidney and blood cells. Methods: Genotoxic effects of ANG II were mea-sured in human kidney (HK-2) and human lymphoma cells (HL60), pigkidney cells (LLC-PK1) and mouse lymphoma cells (L5178Y) by themicronucleus frequency (MN) test and single cell gel electrophoresis—comet assay (CA). Induction of oxidative stress by ANG II was shown byflow cytometry measurement. The presence of the AT1 receptor in thetested cell lines was analyzed by the reverse transcription-polymerase chainreaction (RT-PCR). To attenuate the ANG II action, co-incubation with theAT1 receptor blocker candesartan was performed. Results: In all tested celllines the presence of the AT1 receptor was confirmed. However, there wasno impact of ANG II on lymphoma cells as measured by CA and MN fre-quency test. In both human and pig kidneys cells ANG II caused a dose-dependent DNA damage. We noticed that ANG II enhances oxidative stressas measured by flow cytometry. These effects were abolished using the AT1receptor blocker candesartan. Conclusion: ANG II is a genotoxic agent andcauses a dose-dependent DNA damage in kidney cells, while lymphomacells were resistant.

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P 111 GENOTOXICITY OF hom*oCYSTEINE AND ITSDERIVATESK. Kobras1, J. Vienken2, A. Heidland3, H. Stopper1. 1Dept. of Toxicology,University of Wuerzburg, 2Fresenius Medical Care, Bad Homburg, 3Dept.Of Internal Medicine, University of Würzburg, GermayBackground: In patients with end-stage renal failure genomic damage isenhanced. One of the most probable reasons is the accumulation of uremictoxins in the blood of patients. This study focuses on the effects of the uremictoxin hom*ocysteine (Hcy) and its derivate hom*ocysteine-thiolactone (Hcy-T) because elevated levels have been correlated with an increase of micronu-cleus frequency in healthy persons. Methods: The genotoxic capacity of Hcyand Hcy-T was tested in mouse lymphoma L5178Y cells. The cytotoxicity,number of micronuclei, induction of DNA damage (comet assay) and theapoptotic effect were evaluated. Additionally the impact of Hcy on cell division was analyzed by FACS. Results: A dose-dependent increase in cyto-toxicity and micronucleus frequency was observed in a concentra-tion rangeof 1–10 mM Hcy and Hcy-T. In parallel the number of apoptotic cellsincreased.Additionally these compounds exhibited a strong effect on mitosis.No effect could be observed in comet assay at several time points after treat-ment. Conclusion: At millimolar concentrations, the uremic toxins Hcy/Hcy-T induced genotoxicity in L5178Y cells. The consequences of these find-ings in the physiological context of ESRD patients needs to be elucidated.

P 112 PLASMA TOTAL hom*oCYSTEINE AND CARDIO-VASCULAR RISK IN PATIENTS SUBMITTED TO LIVER TRANSPLANTATIONG. Bianchi1,3, F. Nicolino1, G. Passerini1,3, G.L. Grazi2, P. Zappoli1,R. Graziani1, A. Berzigotti1, R. Chianese1,3, V. Mantovani3, A.D. Pinna2,M. Zoli1. 1Dip. di Medicina Interna, Cardioangiologia, Epatologia, Univer-sità di Bologna, 2Centro Trapianti di Fegato e Multiorgano, Università diBologna, 3Centro di Ricerca Biomedica Applicata, Azienda Ospedaliera,Policlinico S. Orsola-Malpighi, Bologna, ItalyBackground: Patients submitted to orthotopic liver transplantation (OLT)show an increased rate of cardiovascular events. OLT subjects have highhom*ocysteine (Hcy) levels, but no data are available on the association ofHcy with cardiovascular events. Methods: In a cross-sectional analysis, 230subjects were studied at least 6 months after OLT (159 on cyclosporine, 71on tacrolimus). Routine laboratory data and total Hcy were recorded, aswell as the history of diabetes, hypertension, dyslipidemia, overweight. Car-diovascular events occurring in a follow-up of 2–36 months were registered.Results: OLT subjects had higher-than-normal Hcy (median 16.7 mmol/L)without difference between the two immunosuppressive agents. The preva-lence of Hcy > 15 mmol/L was also similar, and significantly correlated withcreatinine levels. 28 arterial events occurred in 25 patients during follow-up. Deep vein thromboses occurred in 2 patients, splanchnic vein throm-boses in 4. Cardiovascular events were frequently associated to high Hcyand hypertension. Cox regression analysis showed that high Hcy was significantly associated with arterial events. Conclusion: High Hcy may beinvolved in the pathogenesis of cardiovascular events in OLT patients. Theusefulness of Hcy-lowering therapy remains to be verified.

P 113 hom*oCYSTEINE AND CARDIOVASCULAR RISK INPATIENTS WITH INTESTINAL TRANSPLANTATIONG. Bianchi1,3, E. Pompignoli2, A. Lauro2, G. Passerini1,3, R. Chianese1,3,V. Mantovani3, A. Pinna2, M. Zoli1. 1Dip. di Medicina Interna, Cardioangi-ologia, Epatologia, Università di Bologna, 2Centro Trapianti di Fegato eMultiorgano, Università di Bologna, 3Centro di Ricerca Biomedica Appli-cata, Azienda Ospedaliera, Policlinico S. Orsola-Malpighi, Bologna, ItalyBackground: Transplanted patients show an increased rate of cardiovascu-lar events and, among cardiovascular risk factors, high plasma hom*ocysteine(HHcy) has an indepedent role. No data are available about HHcy preva-lence in subjects with intestinal transplant (ITX) as effect of immunosup-pressive drugs. Methods: 21 subjects, with ITX dating 6 months or more(median 29 months), receiving Tacrolimus (FK) as major immunosuppres-sive agent, were studied. Total Hcy, assayed on chromatography, routine lab-oratory data, history of diabetes, hypertension, dyslipidemia, overweight andcardiovascular events, were recorded. Results: ITX subjects showed HHcy(median 19 mmol/L); 75% of ITX patients had Hcy >15 mmol/L. The sameprevalence was observed for patients with mild kidney failure (creatininelevels above 1.7 mg/dl). Total hom*ocysteine plasma levels were related toFK serum levels (R = 0.305, P < 0.01). Conclusion: HHcy is frequently foundin ITX patients. Its role in the genesis of cardiovascular events and the use-fulness of a Hcy lowering therapy needs further study.

Artificial Liver 2

P 114 ALPHA-1-ACID GLYCOPROTEIN AS DETOXIFYINGAGENT IN ACUTE HEPATIC FAILUREE.V. Makarov, M.V. Osikov, L.V. Krivohizhina. Chelyabinsk State MedicalAcademy, Chelyabinsk, RussiaBackground/Aim: Detoxifying therapy in acute hepatic failure (AHF),which is a devastating complication of various liver diseases, is patho-genetically sound, thus stimulating development of new pharmacologicalpreparations bearing minimal negative effects. Alpha-1-acid glyco-protein(AGP, orosomucoid), an acute phase reactant, is shown to reduce endoge-nous intoxication in severe burns and is promising detoxifying agent. Theaim of this investigation was to study the influence of AGP on endogenousintoxication in acute hepatic failure. Methods: Experiment was carried outon 40 white male rats. AHF was induced by i.p. injection of 2 ml/kg carbontetrachloride and confirmed by bilirubine, ALT and AST measurements.AGP (Chelyabinsk Blood Transfusion Station, Chelyabinsk, Russia) wasadministered 200 mg/kg i.p. Rats were sacrificed after 48 hours since AHFinduction. Endogenous intoxication was evaluated by level of “low andmiddle weight substances” (LMWS) and Lowry-positive substances (LPS),in plasma and erythrocytes, after treatment of samples with 15%trichloroacetic acid and centrifugation. Results: AHF leads to markedendogenous intoxication: LMWS and LPS in plasma and erythrocytes werehigher than in intact rats (p < 0,05). AGP administration leads to reduction(p < 0,05) of LMWS in plasma, without changes of LPS. AGP did not alterlevels of LMWS and LPS in erythrocytes. Conclusions: AGP shows to bedetoxifying agent in acute hepatic failure. This action is mediated via reduction of LMSW in plasma, probably due to acceleration of their renal clearance. AGP cannot modify levels of endogenous intoxicaton in erythrocytes.

P 115 INFLUENCE OF HUMAN FETAL LIVER EXTRACT ON HEPATOCYTE NUCLEARITY IN CCl4-INDUCED LIVER CIRRHOSISA.M. Malysheva, E.L. Kurenkov,V.E. Ryabinin, S.I. Grobovoy. Chelyabinskstate medical academy, Chelyabinsk, RussiaBackground/Aim: Recently, treatment of chronic liver diseases by means offetal tissues and cell preparations acquired increasing attention. The goal ofthis investigaton was to study the cellular composition of human fetal liverextract (HFLE, 8–10 weeks gestation) and its influence on hepatocytenuclearity in rat model of liver cirrhosis. Methods: Liver cirrhosis (LC) inwhite rats was induced by 2-month administration of carbon tetrachloride(CCl4), with subsequent treatment by HFLE for 2 weeks. Histological andcytological evaluation was done in Romanovsky-Giemsa stained imprintsmears. Results: HFLE treatment lead to recovery of liver parenchyma dueto tissue growth and formation of false lobules. Frequency of micronodularmonolobular cirrhosis in treated rats was 40% less than in CCl4 group. Thisfact indicates reversibility of LC to a certain extent. Regenerative potencyof liver was assayed by hepatocyte nuclearity. In non-treated rats most ofhepatocytes were mononuclear, in treated rats—bi- and three-nuclear. Thispolynuclearity phenomena reflects elevation of liver regenerative capacityas a response on HFLE administration. Cytologically, HFLE consists of fourmain cell types: hepatocytes (29%), stroma cells (16%, including fibroblast-like and lymphocyte-like cells), non-differentiated cells (18%), erythro-caryocytes (all other nucleated cells, 37%). Active liver regeneration isprobably due to erythrocaryocytes and hepatocytes, containing specificgrowth factors and cytokines. Conclusions: Our investigation confirms pos-itive effects of HFLE cells (8–10 weeks gestation) in liver cirrhosis. Furtherelucidation of molecular mechanisms of HFLE action is of high theoreticaland therapeutical importance.

P 116 ISOLATED HEPATOCYTES Vs CLUSTER HEPATOCYTES.IN VITRO PROLIFERATION OF RAT HEPATOCYTES AFTER 30DAYS CULTUREG. Ambrosino*, S.M.M. Basso*, S. Varotto*, E. Zardi†, A. Picardi†,D.F. D’Amico*. *Dept of Surgery and Gastroenterological Sciences, Uni-versity of Padova, Padova, †University Campus Bio Medico, Roma, ItalyBackground and Aim: Hepatocytes transplantation is considered a promis-ing alternative and an effective aid to whole organ transplantation forhepatic failure. Thus, the limited growth of the transplanted cells has beenthe major problem, being the primary requirement of cells in a liver supportsystem the preservation of their in vivo metabolic functions. The aim of this

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study was to compare two different models of hepatocytes isolation inculture: isolated hepatocytes (Group G1) and hepatocytes in clusters (60%hepatocytes, 40% non-parenchymal cells and extracellular matrix) (GroupG2). To test functional activity of hepatocytes, both synthetic and metabolic,production of albumin and benzodiazepine transformation into metaboliteswere tested. Results: G2 showed a high albumin secretion, while a decreaseafter 15 days culture in G1 was noted. Diazepam metabolites were higherin G2 respect to G1 in all samples, but had statistical significance at days 14and 21 (p < 0.01). The glycogen content, after 30 days of culture, was verylow in G1 (14.2% ± 4.4%), while in G2 was 72.1% ± 2.6% (p < 0.01). MTTwas positive in G2, while negative in G1. Conclusion: Our data suggest theeffectiveness of a culture technique with extracellular matrix and non-parenchymal cells to prolong functional activity of hepatocytes. We showedthat isolated hepatocytes maintain their functional activity for a period sig-nificantly reduced, when compared to hepatocytes in cluster and not com-pletely purified. We confirmed the role of extracellular matrix, as crucialcomponent to favorite hepatocytes exchanges and interactions, to promotecellular homeostasis, to maintain polarization and physiological morphol-ogy of hepatocytes.

P 117 EFFECT OF MATRINE ON THE EXPRESSION OFCYTOCHROME P-450, 2A6, AND 2B6 OF PRIMARY HUMAN HEPATOCYTESX. Gong1,2, E.A. Effimova1, F.W.R. Vondran1, X. Cheng1,3, R. Schwartlander,A.K. Nüssler1, D. Yang2, P. Neuhaus1, I.M. Sauer1. 1Klinik für Allgemein-,Viszeral-und Transplantationschirurgie, Charité—Campus Virchow, Univer-sitätsmedizin Berlin, Berlin, Germany 2The First Affiliated Hospital of JinanUniversity, Guangzhou, China, 3Zhejiang Cancer Hospital, Hangzhou,ChinaBackground: Matrine is an extract of the Chinese herb Sophora. It has reg-ularly been used as a hepatoprotective drug in Chinese hospitals and provento be effective when it was applied to patients suffering from hepatitis.However, the mechanisms of its efficacy have not yet been determined. Inthis study, we observed the effect of Matrine on the expression ofCytochrome P-450, 2A6, and 2B6 of primary human hepatocytes in vitro.Methods: Isolation of human liver cells was performed from specimengained after partial liver resection using a typical 2-step-perfusion-technique. The isolated liver cells were kept in monolayer culture for 5 daysin Williams medium E medium. After stimulation of the hepatocytes for 72 h with Phenobarbital (2 mM) or matrine in different concentrations (7,14 and 140 mg/L), the CYP-2A6 and CYP-2B6-associated ethoxycoumarin-O-deethylation (ECOD) was investigated. The protein expression of CYP-2A6 and CYP-2B6 was detected by Western Blot assay, collecting samplesat 12 h, 24 h and 72 h after the hepatocytes were stimulated by matrine asmentioned above. Results: The result of ECOD-assay was summarized asfollow: Matrine and Phenobarbital both increased the ECOD-associatedCYP enzyme activity. Time and dose dependent CYP-2A6 and CYP-2B6protein expression in human hepatocytes cultured with different concen-trations of matrine were seen. There was no significant difference amongthe four groups of CYP-2A6 and CYP-2B6 proteins expression (Control, 7,14 and 140 mg/L Matrine) after 12 h and 24 h stimulation with matrine. 72 hafter stimulation, the expression of CYP-2A6 and 2B6 in the group of 140mg/L matrine was higher than in the other groups. Conclusion: Accordingto the results of the study, we consider that the induction of the proteinexpression of CYP-2A6 and CYP-2B6 is one of the important pharmaco-logical mechanisms of matrine.

P 118 HEPATOCYTE TRANSPLANTATION IN GUNN RATS:IMPROVEMENT IN BILIRUBIN METABOLISMS. Tomat1, E. Gringeri2, F. Calabrese3, C. Giacometti3, P.P. Parnigotto4,U. Cillo2, P. Burra1. 1Department of Surgical and Gastroenterological Sciences, Section of Gastroenterology, 2Department of Surgical and Gas-troenterological Sciences–Section of Surgery, 3Department of Pathology,4Department of Pharmaceutical Sciences University of Padova, Padova,ItalyHepatocyte transplantation could be an alternative to whole organ trans-plantation for patients with inherited defects of hepatic metabolism, buttransplanted cells should maintain their function. The aim of this study wasto investigate the metabolic activity of hepatocytes transplanted into Gunnrats, genetically incapable to coniugate bilirubin. Livers from 20 Wistar male rats were digested by collagenase, 8 ¥ 106 hepatocytes were isolated.hom*ologous acellular matrix (HAM) was prepared by multiples rat liver

slices. Hepatocytes were seeded on HAM and cultured for 3 days. AlbuminmRNA was detected by PCR analysis to assess hepatocyte function. In 12rats (group 1) hepatocyte-HAM sandwich were transplanted into a subcu-taneous cavity of Gunn’s back, HAM was implanted in the same site in 12rats (group 2) and 10 rats (group 3) were sham-operated. No immunosup-pression was used. Tail blood samples were collected before surgery andweekly thereafter for 10 weeks to assess bilirubin levels. Animals were alter-natively sacrified at week 4 or week 8 after surgery. Liver and patches werehistological examined. Bilirubin serum levels were similar in group 2 and 3compared with basal levels during 10 week time. On the contrary, a signif-icant decrease in bilirubin levels was observed from week 4 to 7 comparedto the basal value (p < 0.05) in hepatocyte-HAM sandwich transplanted rats.Histology showed mild granulomatosis and lymphocytic inflammation in the patches of group 1 and 2 at week 4, but not at week 8. Cholestasis wasobserved in 3/6 patches only from hepatocyte-HAM sandwich transplantedrats. Hepatocyte seeded on HAM and transplanted in vivo into Gunn ratsin the absence of immunosuppression maintain the metabolic function.

P 119 TIME-COURSE MAINTENANCE OF SPECIFIC FUNC-TIONAL ACTIVITY IN CULTURED HUMAN HEPATOCYTESE.A. Katenz1, F.W.R. Vondran1, X.B. Gong1, X.D Cheng1, R. Schwartlander1,A.K. Nussler2, P. Neuhaus1, I.M. Sauer1. 1Department of General-,Visceral-, and Transplantation Surgery, Charité, Campus Virchow Clinic,Universitätsmedizin Berlin, Germany, 2Fresenius-Biotech, Bad-Homburg,GermanyBackground/Aim: Primary human hepatocytes serve as a suitable model forbiomedical research and clinical application. The permanent loss of impor-tant liver-specific functions during culturing and limited availability of thehuman hepatocytes demands to define the feasible period of using the cul-tured cells for basic research and clinical application. Methods: Cell isola-tion was performed using a modified two-step perfusion technique followedby density gradient centrifugation. Human hepatocytes were cultured 7 daysunder standard monolayer conditions. Transaminase leakage, proteincontent, albumin and urea formation as well as 7-ethoxyresorufin-O-dealkylase (EROD), 7-ethoxycoumarin-O-deethylase (ECOD), and UDP-glucoronyltransferase activity were assessed. Time course expression ofCYP enzymes was measured by Western Blot analysis. Results: Isolatedhuman liver cells were analyzed from 39 liver specimen obtained after sur-gical resections. After 24 hours of adaptation, 7 days functional period witha low leakage of transaminases and sufficient albumin and urea productionwas observed. However on 5th day of the culture phase I and phase IImetabolism activity were observed only at minor basal level. CYP proteins1A1, 1A2, 2A6, 2B6, 2E1, 3A4 were expressed after 36, 48 hour of culture.At 96 hours post cell isolation most of the cells showed no more expressionof CYP proteins. Conclusion: Progressive decline of liver specific activity inculture confine the useful period to the few days and necessitate the devel-opment of preservation methods for primary human hepatocytes.

P 120 CRYOPRESERVATION OF PRIMARY HUMAN HEPATO-CYTES—PROTECTIVE EFFECT OF TREHALOSE?F.W.R. Vondran, E. Katenz, X.B. Gong, X.D. Cheng, R. Schwartlander,P. Neuhaus, I.M. Sauer. Department of General, Visceral, and Transplanta-tion Surgery, Campus Virchow, Experimental Surgery and RegenerativeMedicine, Charité, Universitätsmedizin Berlin, GermanyBackground/Aim: Large numbers of primary human hepatocytes arerequired for basic research and regenerative medicine. The inappropriatesupply and logistics may be overcome by long term preservation techniquessuch as cryopreservation. We investigated the cryoprotective effect of thedisaccharide trehalose. Methods: Liver samples from patients undergoingpartial hepatectomy were used to isolate hepatocytes by a two-step enzy-matic perfusion technique. At first, the optimal cryoprotective concentra-tion of trehalose was evaluated: primary human liver cells obtained fromidentical donors (n = 3) were frozen with standard cryopreservation solu-tion (culture medium with 10% FCS and 10% DMSO) and varying con-centrations of trehalose (0 to 0.3 M). For subsequent experiments (n = 9)two groups were compared: a control group (no trehalose) vs. the test group(0.2 M trehalose). Following thawing, cell number and viability were deter-mined. Cell culture on multi-well plates was used to investigate specificparameters: plating efficiency, protein content, enzyme leakage (AST,LDH), albumin and urea formation, phase I and II metabolism and a cellproliferation assay. Results: The dose finding study revealed 0.2 M trehalosewith the best overall outcome and thus this concentration was applied for

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subsequent experiments. During these, we found significant improvement(p = 0.004) of the test group in post-thaw viability (62.9 ± 13 vs. 46.9 ± 11%[mean ± SD]) and plating efficiency (41.5 ± 18 vs. 17.6 ± 13%, p = 0.001).On all days of cell culture, results of the proliferation assay and the proteincontent were better in the test group, the latter being significant. Comparedto the control group, the application of trehalose resulted in a significantlyhigher rate of albumin synthesis for most days of culture and a significantly(p < 0.001) lower leakage of AST on day 1. No significant differences wereseen for urea formation, leakage of LDH nor phase I and II metabolism.Conclusion: Trehalose as an additional cryoprotective seems superior tostandard freezing medium containing DMSO only. Best results and thus thehighest cryoprotective effect were found with 0.2 M of trehalose in the cryopreservation solution.

P 121 LARGE-SCALE ISOLATION AND CRYOPRESERVATIONOF HUMAN HEPATOCYTES FROM ALL WHOLE LIVERS UNSUIT-ABLE FOR TRANSPLANT; HEPATOCYTE BANK IS A REALITYA. Cariani, G. Resta, L. Valieri, G. Anania, S. Occhionorelli, S. Ascanelli,G. Cavallesco, G. Azzena. Dept. of Surgery, University of Ferrara, ItalyBackground: Isolated human hepatocytes would represent an ideal in vitromodel for biomedical research. Primary hepatocytes are widely studied assuch, or engineered for clinical applications such as cell transplant andbioartificial livers. An adequate source is required for the various applica-tions, and also for emergency use. Banking is therefore necessary and thusalso a structure able to isolate and store large quantities of such cells. Mate-rials: 30 whole livers obtained by our centre over a period of approximately10 months were used in this study. Metabolic functions have been studied,comparing fresh and cryopreserved cells activities. Results: Our data show that the ATP content and glycogen, both in fresh (ATP = 7.54 ±1.99 nanomol/1 E + 06 cells; glycogen = 9.33 ± 3.03 mg/dl E + 06 cells) andcryopreserved cells (ATP = 6.28 ± 2.82 nanomol/1 E + 06 cells; glycogen =6.58 ± 3.25 mg/dl E + 06 cells) is, on average, lower than that reported in lit-erature; a reduction in metabolic activity, between 24 and 48 hours of singlelayer culture albumin and urea content (-37 and -34%) have beenrecorded; the production of phenacetin metabolites remained constant.Even if the cellular yield, after thawing, is relatively low (20–25% of initialviable cells), using numerically consistent whole organs, a sufficiently highnumber of viable cells (enough to compensate handling and storage costs)can be extracted. Conclusions: Our data indicate that both fresh and cry-opreserved hepatocytes, extracted from any organ, demonstrate the specificmetabolic activities of protidosynthesis and ureosynthesis and phase I andII enzymatic activity. The possibility of using, in a dedicated structure(Bank), whole organs considered unsuitable for transplant for isolation ofhepatocytes is confirmed. The complexity of the organisation necessary forrecruitment and the experience required for isolation of hepatocytes fromorgans unsuitable for transplant have thus far limited this research; howevernowadays this represents the only realistic solution for obtaining humanhepatocytes in large quantities. These results represent a concrete startingpoint from which many potential applications of the hepatocytes in variousfundamental areas of research and clinical application can be envisaged.

P 122 PORTAL VEIN ARTERIALIZATION INCREASES LIVERREGENERATION IN ACUTE LIVER FAILURE INDUCED BYEXTENDED HEPATECTOMY OR TOXIN ADMINISTRATION INTHE RATB. Nardo1, P. Caraceni2, Puviani1, R. Montalti1, R. Bertelli1, P. Beltempo1,V. Pacilè1, M. Licursi1, A.M. Pertosa2, M. Domenicali2, M. Pariali3,M. Bernardi2, A. Cavallari1. 1Department of Surgery and Transplanta-tions, 2Department of Internal Medicine, Cardioangiology and Hepatology,3Biomedical Research Center, University of Bologna, ItalyBackground/Aim: We aimed to determine whether an additional supply ofoxygenated blood achieved by portal vein arterialization (PVA) is protec-tive in rat ALF caused by hepatectomy or toxin administration. Methods:ALF was induced in SD rats by performing an extended hepatectomy or bygiving i.p. 1 ml/kg CCl4. Afterwards, rats were divided to receive PVA, byconnecting the left renal artery to the splenic vein with a stent following leftnephrectomy and splenectomy, or to left nephrectomy and splenectomyonly (control rats). Hepatocyte regeneration was assessed by calculating themitotic index, the bromodeoxy uridine (BrdU) incorporation and the ratioliver/body weights. Liver injury was evaluated by the serum ALT level andnecrotic cell count. The 10-day survival was assessed in separate groups ofrats. Results: As expected, the PVA procedure significantly increased pO2

and oxygen saturation in the portal blood compared to controls (pO2: 63 ±1.6 vs 39 ± 2.9 mmHg; O2 sat.%: 93.1 ± 0.7 vs 67.0 ± 0.5). PVA significantlyimproved survival compared to controls in both ALF models (90% hepa-tectomy: 90 vs 30%; CCl4: 100 vs 40%). Accordingly, in the toxic ALF, serumALT levels and cell necrosis were significantly reduced by PVA (at 24 h:843 ± 344 vs 1493 ± 562 U/L and 32 ± 7 vs 64 ± 15%). The BrdU stainingwas significantly greater in PVA than control rats in both experimentalmodels. Similar results were obtained when the mitotic index was measured.The ratio liver/body weight after hepatectomy recovered significantly fasterin arterialized rats. Finally, when PVA was performed in healthy rats, all theparameters studied were not significantly affected. Conclusions: These dataindicate that the additional supply of arterial oxygenated blood throughPVA promotes a rapid and extensive regeneration leading to a fasterrestoration of liver mass after partial hepatectomy and resolution of toxic-induced massive liver necrosis in rats. Thus, this technique may represent anovel tool for optimizing hepatocyte regeneration during acute liver failure.

P 123 PERSPECTIVES OF ARTIFICIAL LIVER AND XENO-TRANSPLANTATIONK. Naruse. Division of Artificial Organs & Transplantation, Department ofSurgery, University of Tokyo, Tokyo, JapanTo treat patients with metabolic organ failure, liver or kidney transplanta-tion and blood purification therapy, including plasmapheresis, hemodiafil-tration, and bioartificial liver support, are available. We developed a methodof xenogeneic direct hemoperfusion and cross plasma perfusion, in whichplasma is exchanged between the blood circuit of the patient and that of ahepatic functioning unit, through which immunologically free whole humanblood is perfused. From the aspects of efficacy and epidemic safety, the bestsystem of bioartificial liver support for clinical use is considered to be extra-corporeal whole liver system in cross plasma perfusion. On the other hand,it is possible that the combination therapy of hemodiafiltration and theadministration of human serum albumin and anticoagulant factors, whichminimizes the economic and medical resource costs through the develop-ment of transgenic livestock that secrete human pharmaceuticals systemi-cally, will become a more desirable and practical treatment for patients withsevere liver failure. Furthermore, xenotransplantation is a promising pro-cedure for severe hepatic or renal failure patients considering severe short-age of donor organs. We investigate the most practical method of treatmentfor hepatic failure, and introduce our new strategy for xenotransplantation.

P 124 CONTRIBUTION OF HIGH FLUX DIALYSIS TO BILIRUBINREMOVAL IN EXTRACORPOREAL LIVER SUPPORT THERAPYA. Jung1,2, P. Krisper3, B. Haditsch3, R. Stauber4, H. Holzer3, D. Schneditz1.1Inst. of Physiol., 3Div. of Nephrol. & Hemodialysis, 4Div. of Gastroenterol.& Hepatol., Medical Univ. of Graz, Austria 2Dept. of Medical Physics, AGHUniv. of Science & Technol., Krakow, PolandBackground/Aim: Conjugated bilirubin (cb) is significantly bound toalbumin and poorly cleared by conventional hemodialysis (HD). Efficientremoval of cb is possible by fractionated plasma separation and adsorption(FPSA) (Krisper et al., J Hepatol 2005). This technique is realized in thePrometheus system (FMC, Germany) where the blood treated by FPSA issubsequently passed through a high flux dialyzer (FX50) for HD. It was the aim of this study to determine the FX50 contribution to total clearance(Cl-t) of cb during ELS. Methods: Five treatments provided for 3 acute-on-chronic liver failure patients were studied. cb was measured after 0.5, 2, 4,6 and 8 h in the inflow of FPSA and outflow of FX50 to determine totalclearance (Cl-t) as well as in the FX50 inflow to determine FX50 clearance(Cl-FX). Cl was determined for plasma flow. There was no ultrafiltration.Results: Clearances (m L/min) and the relative contribution of Cl-FX rela-tive to Cl-t (Cl-rel, %) at different times are summarized in Tab. 1.

Time 0.5 2 4 6 8 P

Cl-t 25.2 ± 2.0 21.2 ± 2.6 14.5 ± 2.2 11.9 ± 1.7 12.6 ± 1.3 < 0.05

Cl-FX 6.4 ± 2.3 6.3 ± 3.2 4.4 ± 2.3 4.9 ± 1.2 4.0 ± 4.1 n.s.

Cl-rel 25 ± 9 30 ± 16 30 ± 17 41 ± 12 32 ± 33 n.s.

Conclusion(s): While Cl-t decreased during ELS probably because of satu-ration in the adsorbers, Cl-FX remained constant throughout the treatmentproviding approximately 30% of Cl-t. Thus, even though FX50 is designedfor the removal of water soluble solutes during ELS it importantly con-

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tributes to clearance of protein bound solutes such as cb. This may be dif-ferent for unconjugated bilirubin which is stronger bound to albumin.

Tissue Engineering

P 125 HET-CAM BIOMATERIAL EVALUATION GIVES COMPA-RABLE RESULTS TO IN VIVO MODELS REGARDING BIO-COMPATIBILITY PATTERNSC. Eder,1,2, E. Falkner2,3, C. Chiari-Grisar1, H. Schöffl2, U.M. Losert3,S. Nehrer1. 1Dept. of Orthopaedic Surgery, Medical University Vienna,2zet—Centre for Alternative and Complementary Methods to AnimalTesting, 3Core Unit for Biomedical Research, Medical University Vienna,AustriaIntroduction: The HET-CAM (Hen Egg Test-Chorionallantoic Membrane)test system offers a simple and rapid model allowing biocompatibilitytesting of scaffold materials and the simulation of transplantation experi-ments. To investigate whether these data are comparable with data acquiredin animal models, a meniscus regeneration experiment was repeated usingthe HET-CAM assay. Material and Methods: The meniscus implant wasaseptically cut into 5 ¥ 5 mm pieces, which were applied onto the CAM. Thesamples were incubated in ovo for 3 days followed by digital documenta-tion and histological evaluation. The meniscus devices were tested in asheep model by the Dept. of Orthopaedic Surgery, Medical University ofVienna, and data of blood and synovial analyses as well as histological slideswere supplied for comparison. Results: Analysis of the sheep knee jointshowed a good integration and a vascularization of the implant after 1month. HET-CAM analysis revealed a firm attachment of the samples afterthree days and a high vascularization. A synovial hypertrophia observed inthe sheep was visible as hypertrophia of the reticular connective tissue inthe CAM model. Both models showed an inflammatory response and aforeign body tissue reaction. Analysis of synovial smears indicated the pres-ence of lymphocytes in the synovia. Lymphocytosis was also observed in theCAM vessels surrounding the implant. Conclusion: Fertilized, 10 days oldchicken eggs can show a tissue response similar to an animal model. Bio-compatibility and -incompatibility can be tested prior to in vivo implanta-tion. The routine application of the HET-CAM test allows the exclusion ofunsuitable prototypes and facilitate the selection of the best biomaterial foranimal experimentation.

P 126 IN VITRO AND IN VIVO ANALYSIS OF PROTEIN INTER-ACTIONS WITH DIFFERENT STARCH-BASED BIOMATERIALSC.M. Alves1,2, A. Marques1,2, R.L. Reis1,2, J.A. Hunt3. 13B’s Research Group,U. Minho, Braga, 2Dep. Pol. Eng., U.Minho, Guimarães, Portugal. 3Clin.Eng., UKCTE, U. Liverpool, Liverpool, UKAim: In this study we proposed both to analyse in vitro protein adsorptionisotherms, the kinetics and competition of human protein adsorption and toanalyse the in vivo adsorption and protein diffusion onto starch-based bio-materials (SBB). Methods: Biodegradable polymeric blends of corn starchwith cellulose acetate (SCA), ethylene vinyl alcohol (SEVA-C), polycapro-lactone (SPCL) and the TCPS control were investigated. Human SerumAlbumin (HSA) and Fibronectin (HFN) labelled with fluorescent Alexa®Probes were used to prepare single and binary protein systems. The differ-ent SBB were incubated up to 7 h at 37°C and analysed by Fluorimetry andlaser scanning confocal microscopy. SBB implanted in Wistar rats wereimmunostained for key proteins. Images were acquired and protein diffu-sion analysed. One-way ANOVA with post hoc Tukey statistical analysis ofthe results was performed. Results: In the study of single proteins, SCA andSPCL demonstrated comparable adsorption constants, isotherms andkinetic profiles. For competitive systems an increase of both HSA and HFNadsorption for SCA was observed, while SEVA-C demonstrated a positiveeffect only for HSA and SPCL only for HFN. This indicates that there wasan influence of substrate composition on the behaviour of different proteins.In vivo assays demonstrated the formation of a substantial fibronectin layerwhilst smaller proteins managed to diffuse into the bulk of the implantedmaterials. Conclusions: In vitro protein adsorption was modulated by theproteins and the surface and bulk chemistry of the materials. In vivo resultsshowed the variation distribution and range of the different proteins in andon the materials as well as the effect of degradation on protein diffusion.Acknowledgements: FCT, Portugal (SFRH/BD/11188/2002), partial fundingthrough FEDER, POCTI and EU funded Project HIPPOCRATES (NMP3-CT-2003-505758). This work was carried out under the scope of the Euro-pean NoE EXPERTISSUES (NMP3-CT-2004-500283).

P 127 CHITOSAN/POLYESTER SCAFFOLDS SEEDED WITHBOVINE ARTICULAR CHONDROCYTES FOR CARTILAGETISSUE ENGINEERINGJ.T. Oliveira*1,2,3, V.M. Correlo1,2, A. Crawford3, J.L. Mundy3,M. Bhattacharya4, N.M. Neves1,2, P.V. Hatton3, R.L. Reis1,2. 13B’s ResearchGroup, Biomaterials, Biodegradables and Biomimetics, University ofMinho, Braga; 2Department of Polymer Engineering, University of Minho,Guimarães, Portugal; 3Centre for Biomaterials and Tissue Engineering,School of Clinical Dentistry, University of Sheffield, Sheffield, UK; 4Depart-ment of Biosystems Engineering, University of Minnesota, MN, USABackground/Aim: The objective of the present work was to develop a car-tilage tissue engineered construct, by combining a chitosan-poly[butylenesuccinate (PBS)] blended fiber scaffold, with bovine articular chondrocytes.Methods: Chitosan was blended with PBS and processed into fibers, usingan extrusion based methodology, forming a porous scaffold which showedgood interconnectivity and adequate mechanical properties. Bovine articu-lar chondrocytes were seeded under a dynamic environment and the con-structs were cultured for 6 weeks. Construct quality was evaluated using aroutine in-house methodology for cartilage tissue engineered constructs.Results: Presence of hyaline cartilage specific extracellular matrix (ECM)components was confirmed using different methods, such as alcian and toluidine blue, and collagen type II, among others. Conclusion: These novelscaffolds may be suitable for a tissue enginnering approach to cartilagerepair, and should be considered for further studies. Acknowledgements:Portuguese Foundation for Science and Technology (FCT) for PhD scholarship SFRH/BD/17135/2004; the work was carried out under thescope of the European NoE EXPERTISSUES; partial funding by Integrated Project GENOSTEM.

P 128 HUMAN HEMANGIOBLAST FROM BONE MARROW GEN-ERATES IN VITRO HEMATOPOIETIC , ENDOTHELIAL ANDMESENCHYMAL LINEAGESM. Pozzobon1, M. Vittoria Gazzola1, R. Destro1, M. Piccoli1, A. Ditadi2,L. Boldrin1, L. Masiero1, E. Slanzi1, I. Andrè-Schmutz2, L. Zanesco2,M. Cavazzana2, C. Messina1, P De Coppi1. 1Stem Cell Processing Labora-tory and Cord Blood Bank, Department of Pediatric Oncohematology and Department of Pediatric Surgery, University of Padova; 2CR2 INSERMU429 Hopital Necker-Enfants Malades, Paris, FranceBackground and Aim: Many adult tissues contain populations of stem cellsthat have capacity for renewal after trauma, disease, or aging. Bone marrowis the major source of adult hematopoietic stem cells. Moreover, the adultbone marrow contains mesenchymal stem cells, which contribute to theregeneration of mesenchymal tissues such as bone, cartilage, muscle, adiposeand stroma. Antibodies against different membrane antigens have been pro-posed to isolate a specific stem cell population for therapeutic use. It isalready known that the antigen CD133 defines a population of primitiveand immature cells that shows hematopoietic and endothelial capacity.Theaim of our study was to further evaluate the plasticity of CD133+ humanprogenitor cells. Methods and Results: Cells from bone marrow were iso-lated by immune selection method using the anti CD133+ magnetic beads,then plated and expanded on petri dishes. Hence, to confirm their stem cellpotentiality, selected cells were differentiated in vitro into hematopoieticlineages and into bone, muscle, and adipose tissues. Qualitative methods ofimmunohistochemistry such as alkaline phosphatase, von kossa and oil ored hightligth the differentiation capability. Semiquantitative PCR andquantitative citofluorimetric analisys confirmed these findings. Conclusion:In conclusion, preliminary results suggest that, since CD133+ have thepotential to differentiate in several cell types both from the hematopoieticand mesenchymal lineages, they could be a good cell source for therapeu-tic application.

P 129 EXPERIMENTAL ASSESSMENT OF SURGISIS GOLD ASGRAFT FOR NEOINTESTINE REGENERATION IN A RAT MODELF. Gazzotti*, L. Ansaloni*, P. Bonasoni°, F. Catena*, S. Gagliardi*,D. Santini°, M. Taffurelli*. *U.O. di Chirurgia d’Urgenza, Policlinico S. Orsola-Malpighi, Università di Bologna, °Servizio di Anatomia Patoli-gica, Policlinico S. Orsola-Malpighi, Università di Bologna, ItalyAim: Surgisis is an extracellular matrix already used in tissue engineering.The aim of this study was to evaluate the feasibility of using Surgisis as ascafford for small bowel regeneration in a rat model. Methods: A 3-cmlength tubular Surgisis graft was interposed with bilateral anastomosis in

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the median tract of an isolated ileal loop of Sprague Dawley rats used toconstruct an ileostomy. The grafts were harvested and analyzed at each ofthe time-points ranging from 12 weeks to 24 weeks after operation usinghistology and immunohistochemistry. Results: Macroscopic examinationfound no adhesion in the surrounding area of neointestine by 24 weeks, andno stenosis was visible. The shrinkage of neointestine was indicated from20% to 40%. Histologic and immunohistochemical evaluation showed thatat 12 weeks, the luminal surface was covered completely by a mucosal layerwith distinct bundles of smooth muscle cells in the neointestine. At 24weeks, the neointestine wall showed 3 layers of mucosa, smooth muscle, andserosa. Conclusions: The preliminary study shows that Surgisis allow rapidregeneration of mucosa and smooth muscle and might be a promising mate-rial for the creation of neointestine.

P 130 INFLUENCE OF G-CSF ON THE STATE OF VISCERALORGANS IN ACUTE TOXIC AFFECTIONV.N. Zaporozhan, E.L. Kholodkova, D.M. Pikhtyeyev, N.N. Perepelyuk.Odessa State Medical University, Odessa, UkraineBackground/Aim: It is known there is the possibility to use the granulocyte-colony stimulating factor for stem cells activation. It is also known the acti-vated stem cells are directed into the center of damage to realize theirregenerative potentials there. The study of morphological damages of inter-nal organs of rats as a result of action of antracycline antibiotic with subse-quent correction by granulocyte-colony stimulating factor was the purposeof this work. Methods: Animals were parted on 3 groups, one of which(control group—10 animals) got physiological solution. Second group ofanimals, experimental, singly got intraabdominal injection of adriblastin ina dose of 10 mg/kg. Third group of animals, also experimental, were injectedby granulocyte-colony stimulating factor three times in a dose of 100 mkg/kgon the 5–6–7th days after adriblastin introduction. Pathom*orphologicalexamination of heart, liver and kidneys were conducted. Results: The resultsof our researches showed that introduction of adriblastin was accompaniedby the dystrophic and toxic changes of myocardium, liver, kidneys. Thechanges were identical, both in acute and in chronic phases of experiment.At the same time the state of internal organs of animals getting cytokinetherapy after toxic influence was characterized by less degree of expressionof pathological changes, presence of processes of regeneration and devel-opment of compensatory-adaptative reactions. Conclusion: Thus, it is possi-ble to speak about the positive effect of the use of granulocyte-colonystimulating factor on the morphofunctional state of visceral organs after thetoxic influence.

P 131 RED CELL LOADING BY APPLICATION OF SHEARSTRESS ON THE STROMAG. Casagrande1, F. Arienti2, A. Mazzocchi2, M.L. Costantino1, R. Fumero1.1Dept. of Bioengineering, Politecnico di Milano, Milan, 2SIMT IstitutoNazionale per lo Studio e la Cura dei Tumori, Milan, ItalyBackground: Human erythrocytes have a remarkable capacity to undergoreversible membrane swelling with the opening of pores. In the literatureresealed erythrocytes have been proposed as carriers and bioreactors suit-able for being used in the treatment of various diseases. This work is aimedat investigating the possibility of inducing pores formation in the stroma bythe application of mechanical stress, namely shear stress. Methods: Prelim-inary experiments were performed by using a dedicated experimental set-up filled with erythrocytes suspended in PBS containing different molecularweight FITC-dextran that was chosen as diffusive molecule to check stromapores dimensions. The applied stresses were sub-haemolytic. At set timesamples of the suspension were withdrawn from the experimental set-up toevaluate the red blood cells dextran uptake. Flow cytometry and stereooptical microscopy analyses were used. Results: Computer processing of theanalyses outcomes revealed a percentage of cells with significant uptake.Microscopy observations showed that fluorescence-labelled test molecule isable to enter red blood cells. The size of the pores is at least 60 Å that cor-responds to the Stoke’s radius of the biggest test molecule. Conclusions:During each experiment molecular uptake increases with mechanical stress,but optimal mechanical stress value could not yet be identified because theerythrocytes of each donor reacted differently to mechanical stress. Thispreliminary results encourage further studies.

P 132 THE ROBIN HEART CHOREOGRAPHY AND TOOLS FORAOROBAS OPERATIONZ. Nawrat1,2, P.3 Kostka 1,3. 1Foundation for Cardiac Surgery Development,Zabrze, 2Silesian Medical Academy, Zabrze, 3Silesian University of Tech-nology, Zabrze, PolandCardiac treatment, including surgery and artificial organs AO, has madetremendous advances in the last 10 years. New surgery tools (also roboti-cally assisted) allows to introduce minimally invasive cardiac surgery MISthrough “ports”, preserving the integrity of the thoracic cavity. The bloodpumps and valve protheses are more effective and durable but we have’tgot the really permanent AO—it needs service (control of elements), repa-ration. Aim of this work is study of the robot application for AO serviceand implantation. Within the framework of the project created by FCSD,the first in Europe telemanipulators for cardiac surgery, three kinds ofRobin Heart RH prototypes were performed from 2000 to 2003. Ourrealised consequently plans include carrying out of a robotically assisted less invasive procedures to implant VADs, TAHs, valve etc. Based on Robin Heart project development, currently our team works on systemAORobAS—Artificial Organs Robotically Assisted Surgery artificialorgans implantation, services, repair, exchange, removing. The expansion ofminimally invasive surgery MIS techniques for cardiac surgery implicateheart prostheses design and construction. Methods: The computer & phys-ical model for study the choreography and new tools for polish robot havebeen performed. The special physical model for testing the robot in quasioperating room reality have been created. Conclusion: The new models ofrobot tolls and the effectiveness of task realization and optimization ofchoreography have been established. In our team the first work on theassumption for heart pump and valve special for robot & MIS applicationis done and special tools of robot is constructed. The development of thisidea causes changes in requirements for blood pumps construction. Itshould be repairable folding device, with special dimension and the tech-nology for quick mounting of this part to whole pump inside the chest mustbe designed. The study shows the need of new approach on both surgerytools and methods and also the design of AO when the surgical fileds arecombination of soft tissue and hard devices. Additionally, it will change thealso comprehension of man as organism—organeom-contains especiallycreated through peoples biological and technical elements workingtogether.

P 133 CT SCAN ANALYSIS OF THE PULMONARY DISTRIBU-TION OF PERFLUOROCARBON DURING TOTAL LIQUID VENTILATIONP. Bagnoli1,2, G.B. Fiore1, O. Travetti3, C.M. Mocchi3, A. Monaco3, T. Anzani1,F. Acocella3, M. Di Giancamillo3, R. Fumero1, M.L. Costantino1. 1Dept. ofBioengineering, Politecnico di Milano, Milan, 2Dept. of Mechanical Engi-neering, Politecnico di Torino, Turin, 3Dept. of Clinical Veterinary Sciences,Medical Veterinary Faculty, Università degli Studi, Milan, ItalyAim: Liquid Perfluorocarbons (PFC) have linear attenuation coefficientsimilar to those of the contrast agents commonly used in radiology. In thisstudy the pulmonary distribution of PFC in a rabbit model during TotalLiquid Ventilation (TLV) was evaluated. Methods: Spiral thorax CT scans(120 kV, 175 mA, ST 1.00 s, 4 mm thickness/index, 1.00 pitch) were run duringconventional gas ventilation (GV) on 6 adult New Zealand rabbits (bodyweight 3.2 ± 0.5 kg). Scans were performed during respiratory apnoea at endexpiration and end inspiration. The same acquisitions were run while theanimals were TLV-ventilated with PFC FC77 (3M) and repeated duringanimal weaning (after TLV) to evaluate PFC evaporation timing. Results:CT images show that about 10 min after TLV starts the PFC is hom*oge-neously distributed in trachea, bronchi, and alveoli. The attenuation level isalways positive (from 330 to 453 Hounsfield Unit (HU) during expirationand from 408 to 533 HU during inspiration). During the weaning from TLVPFC gradually evaporate from the lung, and after 1 hour lungs appear to becompletely empty. Conclusion: The PFC demonstrated to fill and distendthe airways, showing excellent properties as contrast medium and allowinggood anatomic details.

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P 134 REIMBURsem*nT OF HIGH-PRICED NEW EMERGINGMEDICAL TECHNOLOGIES IN A DRG-BASED HOSPITAL CARESYSTEMF. Hessel, S. Greß, J. Wasem. Institute for Health Care Management, Uni-versity of Duisburg-Essen, GermanyRationale: Newly developed, already licensed, high-priced medical devicesfor critically ill patients impose additional costs especially on the hospitalsector. In countries with a DRG-based reimbursem*nt system there are noeconomic incentives for hospitals to use the new technologies as long as theadditional cost are not compensated. Objectives: The objective of this paperis to analyse the structures of the German health care system which areinvolved in the implementation of new high-priced medical technologies thehospital sector in the reimbursem*nt system and to determine key factorsof a successful implementation. Methodology: The institutions involved inthe determination of the catalogue of reimbursed items based on the justnewly introduced German DRG-system are described and examined. Illus-trated by two examples the launching of newly emerging medical devicesfor inpatient treatment is analysed: Immunoadsorption for patients withdilated cardiomyopathy and a artificial liver dialyses system for patientswith acute liver failure. Both diseases show a high mortality of up to 50%,significantly improvable by the new technology. In both cases the use leadsto additional costs of 13–20,000 EUR per patient treated. Investigated para-meters were the number and quality of studies published, the involvementof health technology assessment institutions, the adjustment of the reim-bursem*nt system in a time frame allowing the survival of the company, andthe dissemination of the technology. Results: and conclusions: Involvementof objective institutions like the Federal Committee (GemBA) or the Insti-tute for Reimbursem*nt in the hospital sector (INEK) is necessary toprevent implementation of new technologies without adequate medical effi-cacy and economic effectiveness. For positive recommendations a criticalmass of clinical and health economic studies is prerequisite. But in timeadjustment of the reimbursem*nt catalogue, e.g. as new DRG or additionalpayment to existing DRGs, seem to be crucial for implementation of a newcostly technology. Slow decision processes can delay if not prevent the useof useful new therapeutic technologies. Although according to the Germanlaw cost effectiveness should be considered in reimbursem*nt decisions, sofar it did not play a relevant role in reimbursem*nt decisions in the hospi-tal sector.

Modeling

P 135 A NEW MATHEMATICAL APPROACH MODELINGTHROMBIN GENERATIONS. Orfao1, G. Jank1, K. Mottaghy2. 1Dept. of Mathematics 2 RWTH Aachen-University, 2Dept. of Physiology, Aachen-University Hospital, GermanyBackground/Aim: The plasma coagulation system is a biochemical chainreaction where inactive proenzymes are converted to active enzymes in acascade pattern. One of the problems encountered in the modeling ofthrombin generation in plasma, is that neither the reaction mechanism northe reaction constants and initial concentrations are precisely known. There-fore, these quantities are taken as unknown parameters in the theoreticalmodel and are estimated by fitting experimental data. In the literature thereare two different mathematical models for approaching a part of the bloodcoagulation mechanism. Both models comprise a stiff system of non-lineardifferential equations. We aimed to analyze both systems after linearization,to steer or influence the system and to calculate the period of time for it toattain a final equilibrium as a basis for a model extension. Methods: Systemsof differential equations, linearization and parameter identification. Fastand slow mode decomposition. Results: The time needed for the steeredsystem to achieve a certain equilibrium was calculated for each control sub-stance with a confidence level of 95%. The extension made preserved sta-bility of system. Conclusions: Linearization preserved the global behaviorof the system and a decomposition into fast and slow modes eases the treat-ment of the stiff system, allowing the study of the dynamic regulation ofblood coagulation reaction and its control. Further, the mathematical modelseems to be a helpful tool in addition to experimental blood coagulationinvestigations.

P 136 ALTERNATIVES TO ANIMAL SERUM FOR CELLCULTURE—2005E. Falkner1,2, H. Appl2, C. Eder2,3, H. Schöffl2, U.M. Losert1. 1Core Unit forBiomedical Research, Medical University Vienna, 2zet-Centre for Alterna-tive and Complementary Methods to Animal Testing, 3Department ofOrthopaedic Surgery, Medical University Vienna, Vienna, AustriaThe cultivation of cells in vitro is an essential tool for biomedical researchand production purposes. For many tasks the supplementation of mam-malian cell culture media with serum (-components) of animal originremains still standard, providing for e.g. nutrition, shear protection, growthfactors and cytokines. Because of undefined/varying composition, risk ofcontamination with prions/viruses/bacteria, the cost factor and also animalwelfare considerations concerning the production of sera, the change toserum free alternatives is promoted by regulatory authorities, the industryand the research community in general. A growing number of alternativesexists for cell lines and primary cultures: chemically defined media, addi-tives of non-serum origin, non-animal derived proteins and also optimizedadaption/sampling/processing protocols and production systems/bioreac-tors for serum-free usage of all scales. A regularly updated product guide(currently 1/2005) can be downloaded as PDF or HTML for free at:http://[emailprotected]. Serum Free Media: Serum free media do not requiresupplementation with serum, nevertheless they may contain various unde-fined proteins and/or protein hydrolysates. Protein Free Media: Supportinggrowth and expression without the presence of proteins, protein-free mediahave eliminated many of the concerns regarding animal proteins in mediasupplementation. Some animal origin materials may remain in the protein-free product, such as amino acids. Chemically Defined Media: All compo-nents have a known chemical structure, resulting in consistent productperformance and the elimination of lot-to-lot performance variability.

P 137 HELICAL FLOW AS FLUID DYNAMIC INDEX FOR THEIDENTIFICATION OF SITES PRONE TO ATHEROGENESIS INAORTOCORONARY BYPASSU. Morbiducci1, A. Redaelli2, R. Ponzini2,3, M. Nobili2, M. Grigioni1. 1Tech-nology and Health Dept, Istituto Superiore di Sanità, Rome, 2Departmentof Bioengineering, Politecnico di Milano, Milan, 3CILEA, ConsortiumInteruniversitary, Milan, ItalyA thorough understanding of blood dynamics in human vessels is of greatinterest, since it is made the local flow behavior of blood certain to beresponsible of the formation of atherosclerotic plaques and of phenomenasuch as atherogenesis and endhotelial damage. Oscillation of shear stress atthe wall were considered relevant for any change in physiological mechan-ical stimuli to the mechano-sensor endothelial cells. To identify the rela-tionships between peculiar blood flow patterns and physiopathologicalevents, the knowledge of detailed haemodynamics data in vessels becomestopical. From this viewpoint, a lively interest arises from the presence ofhelical flow patterns as observed in several vessels. The main purpose of thestudy was to verify if helical flow may be a signature of the blood dynam-ics of vein graft anastomosis. We investigated on the existence of a rela-tionship between helical flow structures and vascular wall indexes ofatherogenesis in models of aortocoronary bypass with different geometricfeatures. In particular, we checked for the existence of a relationshipbetween the degree of helical motion and the magnitude of oscillating shearstress in four conventional hand-sewn proximal anastomosis geometries. Todo it, we designed a computational approach to simulate realistic graft fluiddynamics, including aortic compliance and proper aortic and graft flow rates.A quantitative method was applied for the evaluation of the level of helic-ity in the flow field associated to the four bypass models investigated. Alinear inverse relationship was found between oscillating shear index andthe helical flow index. The results obtained support the hypothesis that anarrangement of the flow field in helical patterns may elicit a damping in wallshear stress temporal gradients at the proximal graft. Helical flow might playa significant role in preventing plaque deposition. From the results obtainedfor helical flow quantification index in vein graft models, it was shown thatthe level of risk for the activation of both mechanical and biological path-ways bringing to atherosclerotic plaque growth, can be discriminated likethe oscillating shear index does. Therefore, results confirm that helical flowconstitutes an important flow signature in vessels.

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P 138 INFLUENCE OF BLOOD FLOW WAVEFORM CREATED BY UPVAD ON ENDOCARDIAL VIABILITY RATIO ANDMYOCARDIAL TISSUE PERFUSIONS. Konno1,Y. Shiraishi1, K. Sekine1,Y. Saijo1,T. Yambe1, S. Nitta1, K. Imachi2,K. Takiura2, K. Tabayashi3, A. Iguchi3, M. Yoshizawa4, D. Ogawa4,P. Olegario4, A. Tanaka5, I. Saito6, S. Mochizuki6, T. Chinzei6, Y. Abe6.1Institute for Development, Aging and Cancer, Tohoku University, Sendai,2Tohoku University Biomedical Engineering Research Organization(TUBERO), Tohoku University, Sendai, 3Department of Thoracic and Cardiovascular Surgery, Tohoku University School of Medicine, Sendai,4Infomation Synergy Center, Tohoku University, Sendai, 5Faculty of Sym-biotic Systems Science, f*ckushima University, f*ckushima, 6GraduateSchool of Medicine, University of Tokyo, Tokyo, JapanBackground: Undulation Pump Ventricular Assist Device (UPVAD) is oneof the most compact VAD systems at present and capable of generating pul-satile blood flow by the mechanism of undulation-type actuater. In thisstudy, the influence of blood flow waveform on the blood supply to themyocardium during cardiac support by UPVAD was examined. Endocar-dial Viability Ratio (EVR), an index of oxygen supply-demand balance inthe myocardium, was calculated under the pulsatile flow as well as contin-uous flow condition. The index was also compared to myocardial tissue per-fusion to evaluate the effect of changes in blood flow waveform created byUPVAD more quantitatively. Methods: Acute animal experiments wereconducted using 5 healthy adult goats. The in-flow canula of UPVAD wasinserted into the apex and the out-flow portion was connected to thedescending aorta. Time-series data of LV pressure and Aortic pressure wasrecorded simultaneously to calculate EVR while UPVAD was driven bothin pulsatile mode and in continuous mode. A laser doppler appliance wasattached to the surface of the myocardium to measure tissue blood perfu-sion during UPVAD support. Results: Effective hemodynamic support byUPVAD was achieved, and EVR was increased by approximately 10%when UPVAD was driven in pulsatile mode compared to continuous mode.It was suggested that myocardial tissue perfusion might also be increasedby pulsatile UPVAD support. Conclusion: A pulsatile blood flow waveformwould be more beneficial for myocardial oxygen supply than continuousblood flow during cardiac support by UPVAD.

P 139 THE SYSTEM OF DIAGNOSIS AND THERAPY OF RESPI-RATORY DISTURBANCES IN STUTTERINGB. Stankiewicz1, B. Adamczyk2, M. Darowski1, K. Zielinski1, M. Guc1. 1Insti-tute of Biocybernetics and Biomedical Engineering, Centre of ExcellenceARTOG, Polish Academy of Sciences, Warsaw, 2Institute of Physics, MariaCurie-Sklodowska University, Lublin, PolandAim: The aim of the study was to assess the breathing process during stut-tering on the basis of the registration of the capnographic curve duringspeaking and rest respiration. The usefulness of the computer systemcreated by the authors for the assessment has been tested. Methods: Theparameters of the CO2/time curve: 1. the end-tidal concentration of CO2

(MCO2); 2. the area of respiratory cycle, i.e. integrated CO2/time signal(SCO2); 3. the average emission of CO2 (ECO2 = SCO2/tcycle), were taken forthe detection and estimation of respiratory disturbances in stuttering. More-over, simultaneous analysis of the capnographic and acoustic signal of anutterance was used to calculate a speech ergonomics factor (FE). Duringthe test, short fluent utterances and simulations of stuttering were recorded.Results: The average values of the ECO2, SCO2, MCO2, obtained for utter-ances, referred to those of rest respiration, were several times (2–5) higherfor stuttering than for fluent utterances. The speech ergonomics factors (FE)were 20% lower for stuttering than for fluent utterances. Conclusion: Theelaborated system detects and effectively recognizes respiratory distur-bances during stuttering. An efficiency test of the therapeutic part of thesystem will be made in the future. Acknowledgements: The study has beensupported in 2004–2005 as grant no. 3 T11E 01727 of the Ministry of Scienceand Information Society Technologies and the Foundation for PolishScience.

P 140 MATHEMATICAL MODELING OF THE CRF PATIENT’SCARDIOVASCULAR RESPONSES DURING PROFILEDHEMODIALYSISK.M. Lim1,2, H.J. Ko3, J.Y. Park1,2, J.C. Kim1,2, J.S. Park1,2, B.G. Min1,2,E.B. Shim4. 1Interdisciplinary Program in Medical and Biological Engi-neering Major, Graduate School, Seoul National University, Seoul, 2KoreaArtificial Organ Center, 3Department of Mechanical Engineering. KumohInstitute of Technology, 4Department of Mechanical Engineering. KangwonNational University, KoreaAim:This study developed a numerical simulation model that can predict theresponse of the cardiovascular system to hemodialysis. Particular attentionwas given to the influence of the sodium profile during treatment. The modelconsists of a closed-loop 12-lumped-parameter representation of the cardio-vascular circulation connected to set-point models of the arterial barore-flexes and cardiopulmonary baroreflexes and three-compartment body fluidand two-compartment solute kinetics models (hemodialysis system model).Method: The hemodynamics of the cardiovascular system are represented as electric circuits with resistors, capacitors, diodes, etc., all of which areassumed to be linear. Once perturbation owing to hemodialysis treatmentgenerates a pressure change in the blood vessels, then control mechanisms(autoregulation system) are triggered by data from arterial and cardiopul-monary baroreceptors. These then work on the systemic arterial resistance,heart rate, and systemic venous unstressed volume. The hemodialysis modelincludes the dynamics of solutes in the intracellular and extracellular pools,and fluid balance equations for the intracellular, interstitial, and plasmavolumes. The model parameters are largely based on literature values.Result: The upward concavity sodium profile is better than the other profilewhich are linear profile and downward concavity profile for preventinghypotension during hemodialysis treatment. Results: The best sodiumprofile for CRF patient’s cardiovascular system stability is the upward con-cavity shape profile. Conclusion: We presented the results of numerical sim-ulation of three different dialysate sodium profiles. In each case, the plasmasodium profile was calculated first using the inverse algorithm, and then thepercentage change of each compartment pressure, heart rate, and ventricularcompliance during hemodialysis were determined. A presumably bestsodium profile is also suggested by the computational model.

P 141 CRITICAL ISSUES ABOUT BLOOD TRAUMA: EVALUA-TION OF MATHEMATICAL MODELSM. Grigioni, U. Morbiducci, G. D’Avenio, C. Del Gaudio, G. Di Benedetto.Technology and Health Dept, Istituto Superiore di Sanità, Rome, ItalyThe main cause of blood damage today in extracorporeal systems andimplantable medical devices is by mechanical damage on blood corpuscles.Artificial organs are normally tested in vitro before in vivo experiments andclinical trials. However, such assessments are not uncontroversial, due to thecomplexity of the in vitro experiments, involving contact of blood with arti-ficial surfaces. Then, it would be of advantage to have a physically consis-tent mathematical model for blood trauma prediction. Red cells damagepredictive models could furnish critical information on both the design andthe evaluation of artificial organs, because their correct usage and imple-mentation are thought to provide clear and rational guidance for theimprovement of safety and efficacy. However, the setting of a theoreticalblood damage models could clash with the complexity of the in vitro set up design. To date, applicable blood damage models have proven to be not completely agreed. The currently adopted power-law shear-inducedhaemolysis prediction models lacks with elements related to the cumulativeeffect of previously applied stress magnitudes, or are not correctly applied.In this study the involved phenomena are identified and the mathematicalliterature on models is reviewed and critically analyzed. The inherentrequirements for modeling mechanical damage to red cells in a physicallyconsistent are dealt with. The aim of the critical analysis consists in provid-ing the background framework towards the assessment and the evaluationof medical devices in terms of blood trauma potential. Moreover, an alter-native model could be proposed where a mechanical quantity was defined,able to describe the blood damage sustained by red cells under unsteadystress conditions, taking into account the load history for erythrocytes. Theproposed formulation predicted the same trend as the available experi-mental data. The obtained results have to be considered a preliminary val-idation of the basic hypothesis of this modified red blood cell damageprediction model. To date, the necessity to design further experiments toovercome inherent limitations of in vitro current systems, to get the time-varying shear stress completely under control, is mandatory.

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P 142 PULSE WAVE PROPAGATION IN SEMI-INFINITE BLOODVESSEL WITH INSERTIONI. Selezov1, G. Pallotti2, P. Pettazzoni2, O. Zvonareva3. 1Department of WaveProcesses, NASU, Kiev, Ukraine, 2Faculty of Medicine and Surgery. Uni-versity of Bologna, Italy, 3Transport University, Dnepropetrovsk, UkraineAim: Heart pulse propagation in blood vessel in the presence of insertionat some distance from the input is investigated. Methods: It is assumed thatthe vessel material is viscoelastic and fluid is viscous. The correspondingproblem is stated and solved by using the Laplace transform in time with aconsequent numerical inversion. Calculations for the radial vessel displace-ment and shear effort are presented and analyzed. Result and Conclusion:In this paper viscous properties of both the vessel and blood are taken intoaccount. The motion of viscoelastic vessel is described by the Kirchhoff-Love shell theory, the blood motion by the equations averaged over thecross-section. Earlier in the similar statement the problems have been con-sidered for a semi-infinite uniform vessel and for jointed vessels. This modeldemonstrates the attenuation and delay of pulse with increasing distancefrom the input and the concentration of shear effort at running the pulse tothe insertion. The existence of the transition junction zone yields a concen-tration of biomechanical stresses and a transport of substance. The latter inthis turn, can lead to pathological changes and thrombus formation.

P 143 ABOUT A NON LINEAR MATHEMATICAL MODEL FORALVEOLAR DIFFUSIONP. Pettazzoni1, F. Albanesi1, E. Caroli2, G. Belmonte3, M. Fabbri3, L. Fasano4,A.M.G. Pacilli3, G. Pallotti3. 1Faculty of Medicine and Surgery, Univer-sity of Bologna, 2INAF/IASF-Bologne, 3Departement of Clinical Medicine and Biotechnology Applied-University of Bologna, 4Hospital S. Orsola-Malpighi, Bologna, ItalyAim: The volume of the alveoli apparently increase and decrease during thebreathing cycle. The convection is dominant in the trachea and bronchi;while at the alveoli level, because the area of the section increase and thevelocity decrease, the diffusion become the dominant process. The aim ofthis study is the formulation of a bio-mathematical description of thisprocess. Methods: If the cross-sectional area A(x) increase with an expo-nential law with coefficient m, the solution of the equation of the motion isgiven by:

where h = U-k·m, and a = h2/(4k), U = U(x,t) the velocity and k = k(x,t) thediffusion coefficient of the gas, m the coefficient of the cross-section expo-nential law and under the following starting conditions for the concentra-tion C(x,t): C(0,t) = 1 and C(x,0) = Co. Results and Conclusion: Thismathematical model of the alveolar diffusion, established the relationshipbetween the lung diffusion capacity and a representative physical propertyof the alveolar region termed effective diffusity. The boundary conditionsinfluence the lung diffusing capacity. This fact makes the lung’s diffusingcapacity, clinically measured via the single breath test, to be a parametersufficient only to establish a diffusion abnormality, but insufficient to dis-tinguish among different reason of respiratory diseases.

P 144 BLOOD GLUCOSE PREDICTION IN TYPE I DIABETICSTHROUGH MATHEMATICAL MODELV. Canonico, D. Fruttini, M. Morettini, M. Massi Benedetti, E. Sarti,P.G. Fabietti. DIMI Dept. of Internal Medicine, University of Perugia, ItalyAim: A mathematical model of insulin-glucose dynamics and kinetics intype I diabetics, already developed and tested on experimental data, is usedto predict the blood glucose course following external inputs such aschanges in the infusion rate of exogenous insulin, meals and i.v. glucoseadministration. Methods: In the model structure a coefficient representinginsulin sensitivity in glucose metabolism is the only model parameter sub-jected to changes over time. At every step of the discrete-time model theestimation of the insulin sensitivity coefficient realises a fine tuning againstpatient response. The model response is then computed to obtain a predic-tion of glucose levels in the future steps. The method has been tested off-line on experimental data collected on 10 type I diabetic patients undercontinuous insulin infusion and blood glucose measurement. Results: RMSerror between computed and experimental data never exceeded 0.6 mmol/l,thus showing a satisfactory correspondence between predicted and actual

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values. Conclusion: The method offers an eligible basis for developing a pre-dictive control of blood glucose during normal life. Model simulation andestimation procedure, performed at convenient time intervals (~5 min), canbe programmed in a wearable or implanted microprocessor unit to performcontinuous blood glucose control during normal life.

Tissue Engineering 2

P 145 CELL AND TISSUE PREPARATIONS IN REGENERATIVEMEDICINE: TREATMENT OF BURN DISEASEYu.V. Gladkikh1, G.S. Lobyntseva1, A.V. Yelskaya2, L.L. Lukash2,G.P. Kozinets3, Yu.P. Rubizov1, O.N. Kovalenko3, A.V. Voronin4,D.V. Lobyntsev1, V.Yu. Gladkikh1. 1Institute of Cell Therapy, 2Institute ofMolecular Biology and Genetics of the National Academy of Sciences of*ckraine, 3Schupikov Academy of Postgraduate Medical Education, 4The 2nd

Clinical Hospital of Dneprovskiy district, Kiev, UkraineBackground: Now, alongside with traditional methods of the burn diseasetreatment physicians began to apply biological preparations of complexaction directed to restoration of homeostasis of patients, processes of repa-ration and regeneration of the damaged skin sites and clinical course as awhole. Methods: We have added to the usual treatment regimen a complexof biological preparations, application of which included mechanisms ofphysiological regeneration and inflammatory proliferation in the field of theburn wound. Cryopreserved stem cells of cord blood were introduced intra-venously and drop-by-drop, cryopreserved tissues of chorion were used ascoverage for the wound surface straight away after necroectomy, cryopre-served fragmented placental tissue within ointments and cultivated allo-genic keratinocytes and fibroblasts were used for single skin sites duringsepticotoxic period. Results: The wound surface debridemented by the bio-logical preparations remained clean, without evident plasmorrhea. On sites,which were processed with embryonic epithelial cells and closed by cryop-reserved tissue of chorion, healing of the wound occurred much faster. Thepresence of stem cells within chorion and placenta did not exclude an oppor-tunity of their migration and proliferation in the field of the wound. We havenoticed a formation of specialized granular tissue and connective-tissueelements. There were no complications connected to graft rejection. Con-clusion: Inclusion of biological preparations in the treatment regimen of theburn disease allows: to stabilize hematologic and biochemical indexes, tostimulate reparative and regenerative processes in an organism, to reduceterms and severity of infectious—inflammatory process, to remove or lowermanifestations of secondary complications, to change character of thewound healing and to achieve an engraftment of autologous skin withoutdevelopment of autoimmune reactions, which make biological preparationsunique and irreplaceable in combustiology.

P 146 ON-LINE MONITORING OF HUMAN EPITHELIAL CELLSBEHAVIOUR EXPOSED TO CYTOTOXIC NECROTIZING FACTORTYPE 1 (CNF1)P. Filippini1, L. Falzano2, V. Contrusciere1, C. Del Gaudio1, C. Fiorentini2,M. Grigioni1. 1Technology and Health Department, Istituto Superiore diSanità, 2Department of Drug Research and Evaluation, Istituto Superioredi Sanità, Rome, ItalyBackground: The analysis of cell impedance temporal variations can represent a novel tool to integrate routinely and well-established laboratoryinvestigational techniques, such as scanning electron microscopy (SEM) orfluorescence assay. The effect of cytotoxic necrotizing factor type 1 (CNF1),a protein toxin from a pathogenic strain of E.coli,was investigated on epithe-lial cells (HEp-2) to evaluate the related time dependent response by meansof cell-substrate impedance sensing (ECIS) set-up. Methods: HEp-2 cellswere inoculated into electrode wells (5000 cells/well), each well in duplicate.After 24 hours fresh medium was replaced, two wells were exposed to CNF1(10-10 M) and two wells were treated with only fresh medium and wereassumed as control. Each well contains a detecting gold electrode (250 mm)as a sensing element for the cell-substrate impedance measurement. Theexperiment was performed for 48 hours. Results: The impedance signal wasanalyzed by means of its components: resistance and capacitance. The mea-sured resistance of the control case showed a quite linear increasing duringthe first 30 hours due to cell spreading and proliferation, then a constantsignal was measured with slight fluctuations super-imposed that can beascribed to cellular micromotility. CNF1 treated HEp-2 cells showed a linearincreasing resistance up to about 24 hours, not different in magnitude

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from the control signal, then a pronounced increasing in the resistance withlarge fluctuations was detected. Conclusion(s): Fluorescence micrographs showed a marked re-arrangement of the actin cytoskeleton in CNF1 treatedHEp-2 cells, which appeared multinucleated as well, moreover cortical actin(ruffles) highlighted the cell enlargement. These dramatic changes in cellularmorphology were also confirmed with the ultrastructural analysis performedby SEM. The high resistance value acquired during the experiment, withrespect to the control case, can be related both to the increment of HEp-2cells area, covering the detecting electrode, and to the decrease of the dis-tance between the cell membrane ventral side and the electrode itself.

P 147 IN VITRO PULSATILE FLOW LOADING CAN DIFFEREN-TIATE EMBRYONIC STEM (ES) CELLS TO VASCULAR WALLCELLSH. Huang1, K. Qin2, K. Yamamoto2, J. Ando2, J.K. Yamash*ta3, H. Itoh3,K. Kanda4, H. Yaku4, Y. Okamoto5, Y. Nemoto5, Y. Nakayama1. 1NationalCardiovascular Center, 2Tokyo University, 3Kyoto University, 4Kyoto Prefectural University, 5Bridgestone Co. Japan.Aim: This study evaluated the possibility of differentiation from embryonicstem (ES) cells to vascular wall cells by physical (mechanical) stress loadingin vitro. Results: Flk1-positive cells (ca. 30%)-containing cell mixture,derived from murine ES cells, was added into a compliant microporous tubemade of segmented polyurethane. The compliance of the tube was close tothat of the human artery (the stiffness parameter = 57.2 (n = 5, SD < 5%)).The luminal surface of the tube was fully covered with the cells by pre-incu-bation for two days in the presence of vascular endothelial growth factor(VEGF). Upon 2 days of additional incubation without VEGF under staticcondition, layering of the grown cells, almost all of which were smoothmuscle actin (SMA)-positive cells, only on the luminal surface of the tubewas observed. The cells were flat, polygonal and randomly oriented. On theother hand, after 2 day-incubation under weak pulsatile flow simulatinghuman venous systems (wall shear stress (WSS); -0.98 ~ 2.2 dyn/cm2, cir-cumferential strain (CS); 4.6 ~ 9.6 ¥ 104 dyn/cm2) without VEGF, cells at thesuperficial layer are regularly oriented in the direction of the pulsatile flow.The oriented cells exhibited endothelial-like appearance indicating plateletendothelial cell adhesion molecule 1 (PECAM1)-positive. In addition, thecells ingrown to the interstices in deeper layer showed smooth muscle-likeappearance indicating SMA-positive. Differentiation to two different celltypes and segregation of incorporated ES cells may be simultaneouslyencouraged by the combination of WSS and CS. Conclusion: Even withoutthe existence of cell growth factors such as VEGF or PDGF, ES-derivedVPCs differentiated to both EC like cells and SMC like cells simultaneouslyunder pulsatile flow condition in vitro. It is expected that the monoblocbuilding of hierarchically structured hybrid vascular prostheses composedof several vascular wall cell types is possible by physically synchronized dif-ferentiation of ES cells.

P 148 BONE GRAFTS WITH PLATELET GEL AND AUTOLOGOUSSTEM CELLS IN TIBIAL OSTEOTOMIES: RANDOMIZED STUDYD. Dallari, C. Stagni, A. Cenacchi, P.M. Fornasari, A. Giunti. Istituto Ortopedico Rizzoli, Bologna ItaliaAim: Orthopedic surgery may be adversely affected by an inadequate repairreaction, which might compromise the success of surgery. Large bonedefects occur as a result of trauma, tumors, infection or removal of ortho-pedic implants. Synthetic or biological substitutes are currently used for thetreatment of bone defects and non-unions. Tissue engineering techniquesare promising tools for bone reconstruction using autologous osteogeniccells. The aim of this study was to assess the in vivo effects of lyophilizedbone grafts, autologous platelet rich plasma (PRP) and autologous bonemarrow stromal cells (BMSC) on bone repair processes after tibialosteotomy for genu varum. Methods: The study protocol was approved bythe Institutional Ethical Committee on human research and was performedin compliance with human studies with the Helsinki Declaration of 1975 asrevised in 1996. Thirty patients, divided into 3 groups by the generation ofrandom sampling numbers, were treated by valgus osteotomy for genuvarum with a minimum correction of 8 mm and fixation using a titaniumplate (TITAN plate Citieffe). The age of the patients averaged 48.9 ± 10.2years (range 25–59 years). The groups were thus divided: Group 1:lyophilized bone chips. Group 2: lyophilized bone chips + PRP, obtainedfrom venous blood (450 g) the day before surgery. Group 3 lyophilized bonechips + PRP + BMSC (Buffy coat). At six weeks X-rays, MRI and needlebiopsies were carried out. The tissue underwent morphological and

microstructural tests. Results: The results confirmed that the use of PRP andBMSC as adjuvant for the lyophilized bone aid bone repair and graft inte-gration. Activated PRP significantly enhanced BMSC differentiationtoward an osteoblastic phenotype. Morphological and morphometric testsshowed that at six week the newly formed bone of group 3 had bettermechanical properties. Radiographic evaluation suggests a faster integra-tion of bone graft in Group 2 and Group 3 with differences statistically sig-nificant at 6 and 12 weeks after surgery. Conclusions: This study shows thatthe use of platelet gel and packed autologous medullary cells combined withlyophilized bone chips produces a faster and mechanically stronger recov-ery of bone stock in the treatment of bone defects.

P 149 EXPRESSION OF MARKERS FOR METANEPHRIC DIF-FERENTIATION INDUCED BY BUTYRIC AND HYALURONICESTERSF. Bianchi,1, G. La Manna1, S. Cantoni2, C. Cavallini2, I. Scarlata2,M.L. Cappuccilli1, E. Persici1, M.P. Scolari1, A. Perbellini2, C. Ventura2,S. Stefoni1. 1Institute of Nephrology, Dialysis and Renal Transplantation,S. Orsola University Hospital, Bologna, 2Laboratory of Molecular Biologyand Stem Cell Engineering—National Institute of Biostructures and Biosys-tems, at the Institute of Cardiology, University of Bologna, Bologna, ItalyBackground/Aim: The recent identification of molecular phenotypes ofrenal progenitors in metanephric mesenchyme (Cadherin 11, CD24, RAR-alpha, Stererolyl-CoA desaturase 2, 14–3-3 ƒ°, Ewing sarcoma hom*olog) hasallowed the utilization of synthetic compounds that have been demonstratedto promote transdifferentiation of metanephric mesenchyme. Hyaluronanmonoesters with butyric acid alone (HB) and its mixed esters with retinoicand butyric acid (HBR) have been used, based on their internalizationthrough the hyaluronan CD44 receptor, and the consequent increase of tran-scription factor accessibility to target cis-acting regulatory sites, associatedwith the histone deacetylase inhibitory action of the butyrate moiety. Thestudy was designed to assess whether these novel differentiating agents mayinduce transdifferentiation into renal progenitors of mesenchymal stem cellsisolated from fetal membranes of human term placenta. Methods: The cellswere grown in monolayer culture in Dulbecco’s minimal Eagle’s mediumwith 10% fetal bovine serum. HB or HBR were added at the concentrationof 1.5 g/l to the medium and the cells were cultured for 7 days. Eventual variations in gene expression profile involving the markers of metanephricdifferentiation have been analyzed by Real-time RT-PCR. Results: The differentiation of mesenchymal stem cells induced by HBR was effective in producing a high throughput of cardiogenesis, but not in metanephric differentiation. In contrast, cell treatment with an association of HB provedeffective in increasing the gene expression of selected markers formetanephric differentiation. Conclusions: These results suggest the utiliza-tion of synthetic compounds for the manipulation of a gene program ofnephrogenic and nephro-specific genes, thus providing a potential approachfor the cell regeneration after kidney damage.

P 150 USING SMOOTH MUSCLE CELL-SEEDED COLLAGENSCAFFOLDS IN TISSUE ENGINEERING OF SMALL INTESTINEY. Nakase. University of Medicine Kyoto, JapanAim: Previous studies aimed to regenerate small intestine with autologoustissues using collagen sponge as a scaffold, but the regenerated intestinelacked a smooth muscle layer. To regenerate the smooth muscle layer, colla-gen scaffolds seeded with autologous smooth muscle cells (SMC) were usedin this study in a canine model. Materials and Methods: Autologous SMCfrom stomach wall were isolated and cultured. Two types of scaffolds werefabricated: in SMC (+) group, cultured SMC were mixed with a collagen solu-tion and poured into a collagen sponge and in SMC (-) group, SMC were notused. Both scaffolds were implanted as patch grafts into defects created inisolated ileal loops. Animals were sacrificed at 4, 8, and 12 weeks; for the lasttime point, the ileal loop had been reanastomosed at 8 weeks. Samples wereexamined by histologic, immunohistochemical, and transmission electronmicroscopic analyses. Results: At 4 weeks, the graft site was infiltrated bynumerous myofibroblasts in both groups. In the SMC (+) group, theimplanted SMC were sparsely distributed among the numerous myofibrob-lasts present in the graft site. The SMC (+) group had considerably highernumber of blood vessels in the graft site when compared with that in theSMC (-) group. At 8 weeks, in the SMC (-) group, the luminal surface wascovered with a monolayer of mucosal epithelial cells and had a thin musclarismucosae. In the SMC (+) group, the luminal surface was covered with aregenerated epithelial cell layer that had a villus-like configuration. The

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implanted SMC were multilayered and formed a thicker smooth musclelayer. In the SMC (-) group, no significant changes were observed in theregenerated mucosa and thickness of the muscularis mucosae betweenexaminations at 8 and 12 weeks. On the other hand, in the SMC (+) group, theluminal surface was covered completely by a well-developed epithelial layerhaving numerous villi at 12 weeks. The implanted SMC were observed in thelamina propria and formed a smooth muscle layer. Transmission electronmicroscopic analyses revealed that SMC that were only seeded in the colla-gen sponge were in a synthetic state. On the other hand, after 12 weeks,implanted SMC changed their phenotype from the synthetic state to con-tractile state. Conclusion: Implanted SMC formed smooth muscle layer and possibly accelerated epithelization of the luminal surface. Thus, it wasconcluded that collagen sponge scaffolds seeded with autologous SMC hadpotential application for small intestine regeneration.

P 151 MORPHOLOGICAL AND CELLULAR VIABILITY CHAR-ACTERIZATION OF ELECTROSPUN PCL SCAFFOLDSC. Del Gaudio1,2, P. Filippini1, V. Contrusciere1, S. Lora3, A. Bianco2,M. Grigioni1. 1Technology and Health Department, Istituto Superiore diSanità, Rome, 2Department of Chemical Science and Technology, Univer-sity of Rome “Tor Vergata”, Rome, 3Institute of Organic Synthesis and Photoreactivity, C.N.R., Legnaro, ItalyBackground: The introduction of bioresorbable polymers can represent animprovement in tissue engineering, specifically to support the regenerationof failing pathological structures, e.g. heart valves and vascular segments.Samples of electrospun poly(e-caprolactone) (PCL) scaffolds, manufacturedmodifying several set-up parameters, were evaluated. Methods: PCL wassolved in tetrahydrofuran (THF) and in a mixture of tetrahydrofuran anddimethylformamide (THF-DMF [1 : 1]) and processed by means of electro-spinning using three different needles (1.2, 1.5, 1.6 mm diameter) to producefive different samples. Morphological investigation was conducted by meansof scanning electron microscopy (SEM) to evaluate the resulting polymericarrangement and to determine the average diameter of fibers. Citotoxicitywas assed via an MTT test on cultured human umbilical endothelial cells(HUVEC) with medium withdrawn from eluted samples in completemedium for 7 days at 37°C and 5% CO2. Finally HUVEC cultures on PCLscaffolds were evaluated using SEM. Results: SEM analysis showed thepresence of beads for two scaffolds while a random mesh with a ratheruniform diameter fiber distribution was obtained for solvent solution THF-DMF and a needle of 1.2 mm, the average diameter being 0.435 ± 0.220 mm.For all the investigated scaffolds, MTT colorimetric assay highlighted anunsignificant difference in the citotoxicity evaluation with respect to acontrol case. Conclusion(s): Electrospinning technique represents a validand current available methodology to produce polymeric scaffolds for tissueengineering. The random arrangement of micro-fibers can furnish the suit-able environment for cellular culture. The preliminary results here pre-sented highlighted the technical reliability to perform cell culture onbioresorbable electrospun polymer manufactured with the modification ofseveral experimental variables. Acknowledgements: This work was partiallysupported by Ministero Istruzione Università Ricerca (PNR 2001–2003,FIRB art.8).

P 152 USING SMOOTH MUSCLE CELL-SEEDED COLLAGENSCAFFOLDS IN TISSUE ENGINEERING OF SMALL INTESTINEY. Nakase1,2, A. Hagiwara1, T. Nakamura2, S. Kin1,2, S. Nakashima1,2,Y. Ikada3, and H. Yamagishi1. 1Department of Surgery and RegenerativeMedicine, Kyoto Prefectural University of Medicine, Kyoto, 2Institute forFrontier Medical Science, Kyoto University, Kyoto, 3Faculty of MedicalEngineering, Suzuka University of Medical Science, Mie, JapanBackground: Previous studies aimed to regenerate small intestine withautologous tissues using collagen sponge as a scaffold, but the regeneratedintestine lacked a smooth muscle layer. To regenerate the smooth musclelayer, collagen scaffolds seeded with autologous smooth muscle cells (SMC)were used in this study in a canine model. Methods: Autologous SMC fromstomach wall were isolated and cultured. Two types of scaffolds were fabri-cated: in SMC (+) group, cultured SMC were mixed with a collagen solutionand poured into a collagen sponge and in SMC (-) group, SMC were notused. Both scaffolds were implanted as patch grafts into defects created inisolated ileal loops. Animals were sacrificed at 4, 8, and 12 weeks; for the lasttime point, the ileal loop had been reanastomosed at 8 weeks. Samples wereexamined by histologic, immunohistochemical, and transmission electronmicroscopic (TEM) analyses. Results:At 8 weeks, in the SMC (-) group, the

luminal surface was covered with a monolayer of mucosal epithelial cells andhad a thin musclaris mucosae. In the SMC (+) group, the luminal surface wascovered with a regenerated epithelial cell layer that had a villus-like configu-ration and the implanted SMC were multilayered. At 12 weeks, in the SMC(-) group, no significant changes were observed in the regenerated mucosaand the muscularis mucosae between at 8 and 12 weeks. On the other hand,in the SMC (+) group, the luminal surface was covered completely by a well-developed epithelial layer having numerous villi. The implanted SMC wereobserved in the lamina propria and formed a smooth muscle layer. TEManalyses revealed that SMC that were only seeded in the collagen spongewere in a synthetic state. On the other hand, at 12 weeks, implanted SMCchanged their phenotype from the synthetic state to contractile state.Conclusion: Implanted SMC formed smooth muscle layer and possiblyaccelerated epithelization. Collagen sponge scaffolds seeded with autolo-gous SMC had potential application for small intestine regeneration.

P 153 TISSUE ORGANIZATION ACCELERATION TECHNOLOGYIN VIVO IN REGENERATIVE MEDICINE: PROMOTION OFANGIOGENESIS BY CONTROL-RELEASED NICOTINEO. Sakai1,2, K. Kanda2, H. Yaku2, T. Sato3, Y. Nakayama1. 1Dept of Bioengi-neering, National Cardiovascular Center Research Institute, Osaka, 2Deptof Cardiovascular Surgery, Kyoto Prefectural University of Medicine, Kyoto,3Dept. of Cardiovascular Control, Kochi Medical Shool, Kochi, JapanBackground: To improve the patency of small caliber artificial grafts,enhancement of tissue reconstruction and endotherialization at the luminalsurfaces is indispensable. It has recently been reported that nicotine couldinduce angiogenesis by activating nicotinic acetylcholine receptors(nAchRs) on the surface of endothelial cells, which stimulates their prolif-eration and the subsequent formation of blood vessels. In this study, we eval-uated tissue formation with angiogenesis promoted by release of nicotinefrom gelatinous matrix in vivo. Materials and Methods: Microporouspolyurethane (PU) sponge scaffolds (6 ¥ 2 ¥ 1 mm) were impregnated withan aqueous solution (ca. 20 ml) of photocurable gelatin (20 wt %) with orwithout nicotine (0.1 wt %), which were subsequently photoirradiated for10 min. Non-treated, gelatin-coated and nicotine-impregnated sponges wereimplanted into dorsal subcutaneous pouches of Wister rats for up to 4 weeks.After predetermined period, tissue formation in and around the spongeswas examined histologically. Results: Nicotine was easily impregnated intophotocurable gelatinous matrix coated on the PU sponges upon photoirra-diation. After implantation, all PU sponges were coved with connectivetissues by one week. In non-treated PU sponges, little angiogenesis wasobserved in the connective tissues and inside of the sponges after 4 weeksof implantation. The PU sponges coated with gelatin without nicotine werecovered with inflammatory hypertrophic tissue absent of angiogenesis. Onthe other hand, angiogenesis was remarkably observed at the connectivetissue in the nicotine-impregnated PU sponges by 2 weeks. Conclusion:Angiogenesis was promoted by nicotine released from gelatinous matrixsignificantly. Nicotine impregnation could be the supportive technique toproduce small caliber artificial grafts with high patency.

P 154 IN VIVO VALVE REGENERATION AFTER RASPING PROCEDUREK. Hayashida1,2, K. Kanda1, T. Inoue1, A. f*ckumoto1, K. Doi1, H. Yaku1,Y. Nakayama2. 1Department of Cardiovascular Surgery, Kyoto PrefecturalUniversity of Medicine, Kyoto, 2Department of Bioengineering, NationalCardiovascular Center Research Institute, Osaka, JapanBackground: A very unique debridement technique for valvuloplasty,rasping procedure, has been applied for clinical cases since 1986. Its suc-cessful intermediate to long-term surgical results were reported by Kita-mura, et al. (Ann Thorac Surg 2000). The purpose of this study is to evaluatethe effects of the rasping procedure on the mechanical and morphologicalintegrity of human aortic valve leaflets in vitro. Methods: We used 3 sets offresh human aortic valve leaflets extirpated during valve replacement. Thethickened lesions of some leaflets were rasped with an electric rasper. Thetreated and untreated leaflets were dissected to the circumferential andradial directions. Each sample was evaluated mechanically by tensile stresstesting, and histologically by HE and EVG stains. Results: In every set ofsamples, the maximum force load to rupture (gf) of the treated leaflet wasequivalent to that of the untreated. On the other hand, significant increasein the strain (%) and decrease in the slope of the curves were observed aftertreatment. These indicated that the treatment significantly improved exten-sibility of the leaflets in both circumferential and radial directions. Mor-

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phological evaluations showed that hypertrophic fibrous and hyalinizedtissue layers were well excised by rasping treatment. Especially in the casesof degenerative changes, the elastic fiber layers were perfectly preservedafter rasping. Conclusions: This is the first study to evaluate the humanvalvular tissues after rasping procedure in vitro. The rasping procedure is avery useful technique for valvuloplasty, which significantly improves themechanical property of the human aortic valve leaflets with no decrease intheir tensile strength.

Tissue Engineering 3

P 155 BEHAVIOR OF SKELETAL MUSCLE CELLS AND CAR-DIOMYOCTES ON EXTRACELLULAR MATRIX COMPONENTS—AN ESSENTIAL COMPROMISE FOR CARDIAC TISSUE ENGI-NEERING PURPOSESK. Macfelda, B. Kapeller, U.M. Losert. Core Unit for Biomedical Research,Medical University Vienna, Vienna, AustriaBackground: Myocardial cell transplantation in patients with heart failureis emerging as a potential therapeutic option to augment the function ofremaining myocytes. Nevertheless further investigations on the basic issuessuch as ideal cell type continues to be evaluated. Therefore the aim of ourstudies was to compare the performance of skeletal muscle cells and car-diomyocytes in respect of their proliferation rate and viability on differentextracellular matrix components (EMC). Methods: Rat cardiomyocytes(RCM) and Rat skeletal muscle cells (RSMC) were cultured on EMC suchas Collagen Type I, IV, Laminin, Fibronectin and Gelatine. The componentswere used as “double coating”. Proliferation rates were determined by pro-liferation assays on day 1, 2, 4 and 8 after inoculation of the cells. Results:The most essential result is that Collagen type I enhances the proliferationrate of RSMC but decreases the proliferation of RCM significantly. Thiseffect is independent of the second EMC used for the double coatingstudies. Other EMCs also influence the cellular behaviour whereas thesequence of the EMCs is essential. Conclusions: Results obtained with ourstudies reveal the significant different proliferation behaviour of RCM andRSMC under ident conditions. As skeletal muscle cells are also used in hearttissue engineering models these results are essential and should be investi-gated in further studies to prove the applicability of skeletal muscle cells forheart tissue engineering purposes.

P 156 IN SITU TISSUE ENGINEERING FOR THE SKELETALMUSCLE REGENERATION USING A COLLAGEN SCAFFOLD IN ARABBIT MODELS. Kin1,2, A. Hagiwara1, Y. Nakase1,2, Y. Kuriu1, S. Nakashima1,2,T. Yoshikawa1, C. Sakakura1, E. Otsuji1, T. Nakamura2, H. Yamagishi1.1Department of Surgery for Functional Regulation of the Digestive System,Kyoto Prefectural University of Medicine, Graduate School of MedicalScience, 2Department of Bioartificial Organs, Institute for Frontier MedicalSciences, Kyoto University, Kyoto, JapanAim: The aim of this study is to regenerate skeletal muscle for reconstruc-tion the levator ani muscle. Currently various operations are performed on patients with lower rectal cancers to preserve anal function, butabdominoperineal excision with permanent colostomy is still mostly per-formed patients with tumor infiltrating the levator ani muscle. To developnew operation method of avoiding colostomy, regeneration of the skeletalmuscle is one of the essential factors to recover patient’s anal function.Material and Methods: Thirty-six Japanese white rabbits were used. Adefect was created on both the vastus lateralis muscle. These rabbits weredivided into 3 groups. (A) The defect covered with the fascia without insert-ing a collagen scaffold. (B) The defect was filled with a collagen sponge andcovered it with the fascia. (C) The defect was filled with a collagen gel andcovered it with the fascia. At time point to 24 weeks after surgery their siteswere evaluated macroscopically and histologically. Results: The collagenscaffold had disappeared completely before 3 weeks and could reduce thecontracture of the muscle defect and the adhesion between the surface ofthe defect and the fascia. Moreover, the collagen gel scaffold seemed toenable the regenerating myotubes to mature through the control of theinflammatory reaction. But the regeneration of the muscle was not histo-logically completed in any group. Conclusion: In this study histologicallysufficient regeneration was not evident in any group, but control rabbitsshowed severe scar formation and contracture. Inclusion of the collagenscaffold appeared necessary to prevent this. Moreover, the collagen gel scaf-

fold enabled the regenerating myotubes to mature, therefore it was seemedthat it might be possible to regenerate the resected levator ani muscle functionally.

P 157 IMPEDENZIOMETRIC ANALYSIS OF FIBROBLASTCULTURE FOR TISSUE ENGINEERING: PRELIMINARY RESULTSC. Del Gaudio1,2, P. Filippini1, V. Contrusciere1, S. Lora2, M. Grigioni1. 1Tech-nology and Health Department, Istituto Superiore di Sanità, Rome, 2Insti-tute of Organic Synthesis and Photoreactivity, C.N.R., Legnaro, ItalyBackground: Tissue engineering represents a promising investigational fieldto assess the possibility to reproduce functional devices as substitutes offailing pathological structures, e.g. heart valves and vascular segments. Theevaluation of eventual cytotoxicity of polymeric scaffolds for cell culturerepresents a relevant issue. An alternative approach based on the mea-surement of impedenziometric response of fibroblast culture is presented.Methods: Poly(e-caprolactone) (PCL) biodegradable scaffolds were manu-factured by means of electrospinning to obtain a randomly arranged meshsuitable for cell culture. Scanning electron microscopy (SEM) was per-formed to evaluate fibers morphology and arrangement. Two circularsamples (12 mm diameter) of biodegradable scaffolds, obtained by solvingPCL in tetrahydrofuran (THF) and in a mixture of tetrahydrofuran anddimethylformamide (THF-DMF [1 : 1]), were bathed for 7 days in completemedium. Successively, fibroblasts were cultured with withdrawn medium ininstrumented wells, equipped with a detecting gold electrode (250 mm diam-eter), to monitor the impedenziometric response for 40 hours. The obtainedresults were compared to a control case: cells cultured in fresh completemedium. Light microscopy was performed to visualize cells distribution onmonitoring electrodes. Results: Electrospun scaffold, manufactured bymeans of THF-DMF solvent solution, highlighted regular fibers distributionwith an average diameter of 0.435 ± 0.220 mm, while in the scaffold obtainedwith THF solvent beads formation can be identified. Normalized impeden-ziometric signals showed similar temporal trends for withdrawn polymericmedium and control case. Cell distribution on electrodes can be related tothe magnitude of the acquired signals. Conclusion(s): Cell impedance analy-sis can represent a novel and alternative methodology for evaluating cellviability. Preliminary results here presented seem to show that the two sol-vents used to produce PCL biodegradable scaffolds via electrospinning donot substantially influence fibroblasts response with respect to a controlcase. Acknowledgements: This work was partially supported by MinisteroIstruzione Università Ricerca (PNR 2001–2003, FIRB art.8).

P 158 HEAD-MOUNTED OPERATING MICROSCOPY SYSTEMFOR ANGIOGENESIS RESEARCHE. Falkner1,2, C. Eder3,4, H. Appl2, U.M. Losert2, H. Schöffl4. 1Core Unit forBiomedical Research; Medical University Vienna, 2zet-Centre for Replace-ment- and Complementary Methods to Animal Testing, 3Department ofOrthopaedic Surgery, Medical University Vienna, 4BioMed-Society for thePromotion of Biomedical and Medical Technological Research in UpperAustria, Vienna, AustriaThe HET-CAM (Hen Egg Test-Chorioallantoic Membrane) angiogenesistest system was standardized for validation by use of a head-mounted oper-ating microscope for both experimental procedures and digital documenta-tion. Today HET-CAM test procedures, documentation and interpretationare usually performed macroscopically with a common hand-held camera.This modus makes it difficult to recognize fine structures and risks genera-tion of artefacts due to bleeding, membrane rips, contamination with bac-teria/yeasts and cooling the in vivo test system below the critical incubationtemperature of 37°C. Reproducibility of generated data is therefore oftenunsatisfactory. Head-mounted microscopy systems offer improved resolu-tion and can also be used in class I/II safety cabinets, minimising the risk ofcontamination and permitting testing of substances potentially hazardousfor the staff. To establish a Standard Operating Procedure (SOP), CAM dis-section and specimen application procedure protocols as well as the tech-nical equipment must be standardised. Miniature head-mounted M5 testedby the authors enables the operating microscopes like the Varioscope userto analyse objects difficult to access with the required magnification andoperating distance and to manipulate them precisely. Automatic sensorsdetect the object continuously and adjust the optics, documentation is dig-itally performed from the experimenter’s visual angle, zoom is stagelesslyvariable, the pivoting radius is 72°. This kind of optical vision enhancementis used in operating theatres/dental clinics and manufacture/quality

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control of precision M5 allows standardisation of CAM experimental procedures/components. Varioscope following Good Laboratory Practice (GLP) rules.

P 159 THE DIDECO “PLURICELL SYSTEM”: A MEDICALDEVICE FOR THE EX-VIVO EXPANSION OF HEMATOPOIETICSTEM CELLSG. Astori1, V. Adami2, G. Mambrini1, L. Bigi1, M. Cilli3, A. Facchini4,E. Falasca2, W. Malangone2, I. Panzani1, A. Degrassi5. 1DIDECO srl Mirandola (MO), 2SB Technology, Udine, 3Servizio Modelli Animali, IstitutoNazionale Ricerca sul Cancro, Genova, 4Laboratorio di Immunologia eGenetica, Istituti Ortopedici Rizzoli, Bologna, 5DPMSC, Universita’ degliStudi di Udine. ItalyBackground/Aim: The Dideco “Pluricell System” is a commercially avail-able CE-marked device composed by an expansion chamber and a kit ofcertified reagents for the ex-vivo expansion of hematopoietic stem cells. Wehave expanded seven umbilical cord blood (UCB) samples following themanufacturer’s instructions. To verify the ability of expanded cells to suc-cesfully engraft the bone marrow (BM) of irradiated mice, two groups ofNOD-SCID mice have been transplanted with unexpanded and nonex-panded cells from the same UCB, and the BM was analysed for the pres-ence of human cells after six weeks. Methods: UCB CD34+ cells wereselected using the MACS progenitor cell isolation kit and ex-vivo expandedin Pluricell. Mice were irradiated at 300 cGy using a 137Cs source. Pheno-typical characterization of cells was performed by FACS. Results: Theaverage UCB volume was 61.6 ± 8.8 ml and the mean nucleated cell content1090.5 ± 189.9 ¥ 106. Percentage and number of CD34+ cells were 0.37 ±0.13% and 3.9 ± 1.2 ¥ 106. After separation, CD34+ purity was 82 ± 11%.The mean number of cells seeded in Pluricell was 760.000. The mean NCand CD34+ fold expansion at 12 days were 230.4 ± 91.5 and 21.0 ± 11.9respectively. The expanded cells were constituted for the majority ofmyeloid and megakaryocytic progenitors. The CD34+ antigen reached themaximum level at day 12 (7.5 ± 2.0%). Conclusions: Both groups of miceshowed successful engraftment. Interestingly, the percentage of human cellsin the mice BM was higher in the group receiving expanded cells (3.4 ±2.01%) compared to the group receiving unexpanded cells (1.5 ± 0.66%) (p < 0.00018). Analysis of lineage-markers for human myelomonocytic,megakaryocytic, B, T, CD34 and erythroid cells, gave evidence that all thelineages were represented in the BM of mice. The Dideco Pluricell allowsan efficient expansion scale-up; moreover, the use of a CE-marked deviceprovided with certified reagents, could facilitate the use of expanded cellsin the clinical setting.

P 160 PVA DEVICES COMPOSED OF PANCREATIC RAT ISLETSSEEDED ON hom*oLOGOUS ACELLULAR PANCREATICMATRIXE. De Carlo1, S. Vigolo1, M.T. Conconi2, S. Lora2, N. Sicolo1, C. Martini1,P. Maffei1, G. Tamagno1, R. Vettor1, P.P. Parnigotto2. 1Department of Medicaland Surgical Sciences, Clinica Medica III, University of Padova, 2Instituteof Organic Synthesis and Photoreactivity, CNR, Legnaro (Padova), 3Depart-ment of Pharmaceutical Sciences, University of Padova, ItalyBackground/Aim: The survival of pancreatic islets represent a key step toguarantee the success of cell-based therapies for type I diabetes. Nowadays,several evidences suggest that acellular matrices are able to support theadhesion and growth of many cell types. Moreover, the immunoisolation oftransplanted cells is needed to avoid rejection responses. In this study wehave evaluated whether i) islets seeded on acellular pancreatic matrix(APC) and inserted in tubular structures of poly(vinyl alcohol) (PVA) couldmaintain a long-term function in vitro, and ii) PVA devices could controlglycemic levels of streptozotocin (STZ)-treated rats. Methods: Rat pancre-atic islets were obtained by collagenase digestion and seeded on hom*olo-gous APC prepared with a detergent enzymatic method. Then the cultureswere inserted into PVA tubular membranes. Glucose-induced acute insulinrelease was evaluated by RIA until 6 weeks from seeding. PVA tubulardevices containing 1.5 ¥ 103 islets cultured on APC were subcutaneouslyinserted in twelve male Wistar rats, previously treated with STZ. Bloodglucose and insulin levels were measured daily and every week, respectively.The animals were sacrificed 6 weeks after the surgery and immunofluores-cence was performed on paraffin sections using anti-insulin and -glucagonantibodies. Results: In vitro glucose-induced insulin release was maintaineduntil 6 weeks. In vivo all implanted animals exhibited a reversal of hyper-

glycaemia and insulin levels were higher in comparison with non implantedSTZ rats. Moreover, several islets expressing both insulin and glucagon werepresent inside the implants. Conclusion(s): Our results demonstrate thatAPC, an organ-specific biological substrate, may be useful in order toimprove in vitro and in vivo islet function and survival.

P 161 DYNAMIC IN VITRO ASSAYS OF A HOLLOW FIBER BIO-ARTIFICIAL PANCREAS WITH RAT ISLETS AND beta-TC-3CELL LINEA.I. Silva, M. Mateus. Centre for Biological and Chemical Engineering,Instituto Superior Técnico, Lisboa, PortugalBackground/Aim: A bio-artificial pancreas (BAP) construct was estab-lished, enabling an easy in vitro follow-up and modelling of BAP responseto system changes (cellular, molecular, structural). The device was seededwith rat islets of Langerhans or beta-TC-3 mouse insulinoma cells, co-immobilized with agarose beads. The level of insulin secreted by the encap-sulated islets or beta-cells was assessed. Methods: The device consists of a6.5 cm-long made of 100 kDa polysulphone hollow fibre in a glass casing,inserted in a closed medium re-circulation circuit. Islets or beta-cells wereinserted in the annular space between the membrane and the glass walls,together with agarose microspheres, and cultured until a cellular responsewas detectable. Islets culture medium was CMRL-1066 with low glucose(6.7 mM) and glucose challenges were performed with high glucose medium(20 mM) for 7–8 h periods. For beta-TC-3 cells, the culture medium was HighGlucose DMEM (25 mM). Glucose stimulus occured for 2 h with DMEMlow glucose (5.55 mM), followed by 2 h with High Glucose DMEM. Therewas a previous 2 h-washing step. Insulin released through the membranewas quantified by ELISA. Results: Fifty islets inserted in the BAP annularspace remained functional for 9 days, presenting a measurable response tohigh glucose levels, with a peak of insulin concentration detected on day 4 (average insulin released 0.36 pg/mL/beta-cell). Under similar conditions,1 ¥ 10Ÿ7 b-TC-3 cells presented measurable concentrations of insulin for 7days, with a maximum average release of 3.4 ¥ 10Ÿ-3 pg insulin/mL/beta-cellon day 3, at the end of the stimulus. The use of isobutyl-methylxanthineenhances the increase of insulin released from these cells up to 12-fold. Con-clusions: Islets of Langerhans and beta-TC-3 cells are equivalent biologicalmodels for the study of a hollow fibre bio-artificial pancreas, achieving com-parable levels of insulin release under similar conditions and over the sametime. Although beta-TC-3 cells cannot replace the islets of Langerhans asglucose level regulators in vivo, they provide a good source of fast growing,insulin-producing cells, ideal for in vitro studies of membrane and systemstructure and behaviour under different experimental conditions.

P 162 ESTABLISHING ECMO IN A UNIVERSITY CLINIC—OUREXPERIENCEJ.M. Kahn1, H.M. Müller1, W. Marte2, A. Wasler1, K.H. Tscheliessnigg1.1University Clinic of Surgery, MedUni Graz, 2University Clinic of Anaes-thesiology, MedUni Graz, Graz, AustriaObjectives: Although ECMO (extracorporeal membrane oxygenation) is awell-established therapy for respiratory failure in neonates, application inadults is discussed controversially. Generally accepted recommendations forapplication of ECMO in adults do not exist. In recent literature the survivalrate of patients with ARDS (acute respiratory distress syndrome) andECMO-therapy is stated with 50%. Material and Methods: Since Septem-ber 2004 10 patients with ARDS have been placed on ECMO in our hos-pital. In 8 patients veno-arterial (VA), in 2 cases veno-venous (VV) ECMOwas established. Indications were: 1) peritonitis with ARDS 3 weeks afterliver transplantation (VA), 2) pulmonal leptospirosis (VA), 3) septic pul-monary embolism (VA), 4) atypical pneumonia (VA), 5) aspiration (VA),6) nearly-drowning (VV), 7) pericardial tamponade with shock- lung (VA),8) right heart failure after heart transplantation (VA), 9) CPR because ofpostpartal bleeding (VV), 10) chronic thromboembolic PH (VA). ThepaO2/FiO2-ratio was less than 100 in all patients prior to the beginning ofECMO-therapy. Results: 7 out of 10 patients (70%) could be weaned fromECMO successfully. 3 patients (patient 4), patient 5), patient 8)) died fromtheir primary disease. In three cases (patient 2), patient 4), patient 8)) sur-gical re-intervention was necessary due to bleeding, in one patient a switchof the canules from left-femoral to right-femoral had to be performed dueto femoral venous thrombosis. The average maintenance of ECMO-therapywas 5 days. Conclusions: ECMO has been proven to be a successful conceptin the therapy of ARDS, when conventional strategies have failed. An inten-

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sive preparation and interdisciplinary collaboration between anaesthesiol-ogists, cardiotechnicians and surgeons is necessary for a successful estab-lishment of this therapeutic option.

Artificial Lung

P 163 OVER TWO MONTHS OF CONTINUOUS CARDIOPUL-MONARY SUPPORT IN GOATS USING A NOVEL PEDIATRICEXTRACORPOREAL MEMBRANE OXYGENATION SYSTEMWITHOUT SYSTEMIC HEPARINIZATIONK. Ota1, E. Tatsumi1, Y. Taenaka1, N. Katagiri1, T. Mizuno1, R. Kansaku1,Y. Kakuta1, H. Lee1, T. Tsukiya1, A. Homma1, E. Akagawa1, M. Sato2,H. Tanaka2, K. Sakai3, T. Matsuda3. 1Department of Artificial Organs,National Cardiovascular Center, Osaka; 2Toyobo Co., Ltd., Osaka;3Dainippon Ink and Chemicals Inc., Tokyo, JapanBackground/Aim: We developed an excellent anti-thrombogenic ECMOsystem for child. It consists of a compact oxygenator made of leaklessspecial hollow fiber membrane (Platinum Cube NCVC 2000, membranesurface area: 0.4 m2, priming volume: 45 mL), and a sealless durable cen-trifugal pump (Jostra RotaFlow). The entire blood-contacting surface iscoated with our heparin coating technique T-NCVC coating that impartshigh anti-thrombogenicity. The aim of this presentation is to demonstratethat the newly constructed system has high anti-thrombogenicity and long-term durable performance. Methods: We firstly examined possible heparinelution from the circuit that may cause severe hemorrhagic complicationsin pediatric ECMO. Venoarterial ECMO for 24 hours was undertaken intwo young goats (20 and 25 kg), and the levels of eluted heparin and theother clotting factors were measured. Systemic anticoagulantion was notconducted even at the time of cannulation. Secondly, we put this system intoprolonged heparinless ECMO in two young goats (20 and 30 kg) to evalu-ate its durable performance. Results: In first experiment, the blood heparinconcentration was always less than detectable level. The ACT and APTTlevels were kept normal for 24 hours. In secondary cases, the system couldbe continuously perfused for 9 and 7 weeks until elective termination.Bypass flow was maintained at around 1.5 L/min. The O2 and CO2 trans-fer rates were 70–90 ml/min and 30–60 ml/min, respectively. Plasma leakagefrom the oxygenator did not occur. The levels of ACT, APTT, and plateletscount were kept within physiological limits. In postmortem, a small amountof thrombus originating from the centrifugal pump was observed at theinflow of the oxygenator fiber bundle, whereas the other parts of the circuitincluding the inside of the fiber bundle were completely free from throm-bus formation. Conclusion: The newly developed system has an ability tobe used for long-term pediatric ECMO without heparinization.

P 164 MODELLING OF TWO-PHASE FLOW DURING PULSATILEPULMONARY AIRWAYS REOPENINGB. Kuraszkiewicz, M. Darowski. Institute of Biocybernetics and BiomedicalEngineering PAS, Warsaw, PolandBackground: Pulmonary airway reopening requires a semi-infinite bubbleto penetrate the fluid obstruction and to separate airway walls. This processmay damage epithelial tissue by the application of mechanical stress (shearand normal) as the bubble progress through the obstruction. Pulmonary sur-factant reduces these stresses, but during steady reopening the surface ten-sions are higher than equilibrium. In presented paper it is hypothesised thatpulsatile reopening may reduce venitor—induced lung injury by optimizingsurfactant transport through fluid mechanical and surface—structure inter-actions. Premature infants may have under—developed lungs that do notproduce adequate surfactant that is required for normal lung function. Thisis known as Respiratory Distress Syndrome (RDS). Mechanical ventilationnecessary to sustain these infants can potentially cause severs damage tothe sensitive lung tissue. Aim/Hypothesis: The coupling between unsteadyflow and surfactant adsorption dynamics can be used to optimize surfactanttransport during airway reopening, thereby minimizing damage to the lung.Method: The movement of a bubble through a pulmonary airway can bemodelled (simply) by the propagation of an air bubble down a 2-D, rigid—walled channel. The system is composed of a channel filled with a Newton-ian fluid that is driven by a downstream volume flux. In presented paperpulsatile motion of a semi-infinite gas bubble of surface tension (g) in a hor-izontal channel of width (2R), filled with a liquid of viscosity (m), was mod-elled. It was modelled the mechanical response of the system to a volumeflux (Q(t)) with mean (Q0) and oscillatory component (Qw) with frequency

(w). The behaviour is characterized by the average capillary number (Ca),relating viscous to surface tension forces, and the oscillatory forcing mag-nitude (Caw). The dimensionless frequency (W) relates oscillatory—forcingand viscous—draining time scale. The presented problem was described byevaluation equations with kinematics condition. Conclusions: A preliminarymodel of pulsatile pulmonary airway reopening was described. It is a toolfor finding an optimal oscillation frequency that will maximize surfactanttransport at the air—liquid interface and thus will reduce ventilator—induced lung injury.

P 165 THE NCVC ULTRA-DURABLE HEPARINLESS ECMOSYSTEM: CURRENT STATUS OF DEVELOPMENTE. Tatsumi1, Y. Taenaka1, N. Katagiri1, T. Mizuno1, K. Ota1, T. Tsukiya1,A. Homma1, Y. Takewa1, M. Sato2, H. Tanaka2, K. Sakai3, T. Matsuda3.1National Cardiovascular Center, Osaka, 2Toyobo Co., Ltd., Osaka, 3Dainip-pon Ink and Chemicals Inc., Tokyo, JapanBackground: ECMO is the only option in treating the patients with lifethreatening severe respiratory failure. The current ECMO system, however,has two major limiting barriers to its extensive use: 1) poor antithrombo-genicity that necessitates systemic heparinization, 2) poor durability espe-cially due to plasma leak from microporous membrane oxygenator. At theNational Cardiovascular Center (NCVC) of Japan, an ultra-durable heparin-less ECMO system has been developed. Methods: The system consists of acompact leakless oxygenator (PlatinumCube-NCVC series), and a seallessdurable centrifugal pump (RotaFlow). The oxygenator is made of specialhollow fiber membrane in which micropores are blind-ended at the blood-contacting surface to prevent plasma leakage. Membrane area and primingvolume are: 0.4 m2 and 45 ml in S-type, 0.8 m2 and 95 ml in M-type, and 1.3 m2

and 130 ml in L-type, respectively. The entire blood-contacting surface is coated with a novel heparin material (T-NCVC coating) that impartsextremely potent antithrombogenicity. Heparinless veno-arterial bypassECMO was carried out in chronic animal experiments using 15 goats weigh-ing from 20–60 kg (2 for S-type, 3 for M-type, and 10 for L-type). Systemicanticoagulation was not conducted at all, except for one-shot heparin injec-tion at cannulae insertion. Results: Heparinless ECMO could be run for upto 3 months (34–92 days) until elective termination. Bypass flow was main-tained between 1.5–3.0 L/min. Gas-exchange function was kept stable at sufficient level for provided blood flow. Plasma leak was not observed in anycase. Platelet count, ACT, APTT, and fibrinogen were kept normal, and theblood heparin level was always less than measurable level. Hematologicaland blood chemical data also remained normal. In postmortem examination,some clots were seen at the marginal area of the inlet and outlet of oxygena-tor, but the fiber bundle was always surprisingly clean. The other parts of thecircuit were completely free of thrombus. Conclusion: The results of thisstudy indicate that our ECMO system has an ability to be used for a periodof months long-term support with minimal or no systemic heparinization.

P 166 ANALYSIS OF BLOOD FLOW IN ARTIFICIAL LUNG BY X-RAY COMPUTED TOMOGRAPHYF. Kohori, K. Sakai. Department of Chemical Engineering, Waseda Uni-versity, Tokyo, JapanBackground/Aim: Performance of an artificial lung mainly depends onblood flow state. Channeling of blood flow and contact failure betweenblood and membrane impair performance of the artificial lung. Moreover,the stagnation of the blood flow makes the thrombus. In short, the bloodflow must be uniform in artificial lung. The purpose of this study is to elu-cidate optimal conditions to develop uniform blood flow. Therefore, x-raycomputed tomography (CT) was used for the analysis of the flow state inan artificial lung. Methods: The actual blood flow state in the commerciallyavailable artificial lung was measured with the X-ray CT. Cylindrical artifi-cial lung, HPO-20H (Senko medical, Tokyo), was used. First as primingoperation, the glycerol solution of which the viscosity was almost equal toblood was flowed. Secondly, the glycerol solution which contains the X-raycontrast media was flowed by the switching of three-way co*ck. Hounsfieldnumbers, which show the absorptivity of the X-ray, were measured at 15points in the hollow-fiber-filling part. The X-ray contrast media, Iopamiron370 (Nihon Schering, Osaka), was used. The flow rate was changed from 1L/min to 5 L/min at each 1 L/min. Results: At the low flow rate (1–2 L/min),the Hounsfield number gradually rises, while it fluctuates. The instability ofthe Hounsfield number indicates the stagnation of the test solution. Theunstable flow accumulates the possibility of generating the thrombus, and

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the use at the low flow rate can not be very much recommended. At theflow rate of 3 L/min, the Hounsfield number keeps rising, which indicatesthe test solution doesn’t stagnate. However, it is observed that the climbingspeed of the Hounsfield number at the upper part is smaller than other part.In short, the test fluid is difficult to infiltrate in the upper part of the artifi-cial lung. From time course of the Hounsfield number at high flow rate (4–5 L/min), the test solution flows more uniformly than other flow rate.From this fact, high flow rate prevent stagnation and channeling in artificiallung. Conclusions: Flow conditions in artificial lung are different by flowrates. Therefore, the optimum artificial lung must be selected from the view-point of flow rate. Especially, attention is necessary in the low flow rate, sincestagnation and channeling are easily generated.

P 167 ARTIFICIAL TRACHEA DEVELOPMENT USINGOMENTUMJ.H. Kim. Biomedical Engineering, SungKeunKwan University School ofMedicine, Seoul, KoreaBackground/Aim: Prerequisites for successful trachea reconstruction arebiocompatible material and reepithelialization of trachea epithelial layer.The reepithelialization achieved from use of self-originated cells that cul-tured by in vitro. But the agelong in vitro culture for obtaining adequateamount of cells can cause functional depression and phenotype abnormal-ity. And, after trachea transplanting operation, there are not sufficient bloodvessels to cell growth. To solve these problems, we used omentum for cellculture and blood vessel formation. It is consisting of very wide adiposemembrane and many small blood vessels. Our preceding experiment haveidentified that omentum culture are prior to in vitro culture in terms ofblood vessel formation and ECM constructs. Methods: 1. Trachea prosthe-sis with skin epithelial cell Abdominal skin patches were harvested frommongrel dog. The epithelial cells were separated and cultured in vitro forthree weeks, and then seeded onto a porous PLGA-Polypropylene pros-thesis framework. 2. Trachea prosthesis culture on omentum and transplantto trachea The prosthesis was wrapped with the great omentum of the samedog and placed in the peritoneal cavity for one week. Complete surgicalresection and replacement of a thoracic tracheal segment (5 cm in length,just above the carina) was then performed using the prosthesis. 3. SEM andhistological analysis by H/E staining To identify scaffold pore and cellculture status, the PLGA scaffold and cell cultured-PLGA scaffold werefixed in 2.5% glutaraldehyde. Luminal surface of replaced trachea wasobserved to evaluate incorporation of mesh-PLGA scaffold with host tissueand surface character. Results: Reepithelialization and blood vessel forma-tion and trachea reconstruction were achieved well. The omentum cansupply nutrients and oxygen and cover cell-material component that diffi-cult to be covered by skin or muscle flap. Also it make fibrosis basis thatrequired cell growth, so the basis play an important role in epithelial cellgrowth and differentiation and solve air-leakage that is another very impor-tant point of trachea reconstruction. Conclusion: We concluded that use ofomentum for trachea reconstruction is reconstruction of efficient and effec-tive method and this method can be used in other internal organ.

P 168 ASSESSMENT OF THREE PEDIATRIC ENDOTRACHEALTUBES OF DIFFERENT DESIGN BASED ON FLOW RESISTANCEAND WORK OF BREATHING MEASUREMENTSB. Stankiewicz1, M. Darowski1, M. Rawicz2, J. Glapinski1, M. Michnikowski1,A. Rogalski1. 1Institute of Biocybernetics and Biomedical Engineering,Centre of Excellence ARTOG, Polish Academy of Sciences, Warsaw,2Department of Anaesthesiology and Intensive Care, Warsaw Medical University, Warsaw, PolandAim: We have compared resistances to 100% oxygen flow of 3 pediatricuncuffed endotracheal tubes of various design: a standard (one-diameter),Cole and a newly designed cone tube. We have calculated correspondingresistive works of breathing (RWOBs), resulted from using them. Methods:The flow (0–30 Lpm) resistance was measured across each tube andrepeated for 4 and 3.5 mm ID. The RWOB for every tube was determinedfrom the simulation of an intubated, spontaneous breathing infant. The pressure/volume loop was generated for virtual lungs and CPAP circuit bythe specially designed software and subsequently, RWOB was calculated.Results: The resistance of cone tubes to 20 Lpm 100% oxygen flow was20–40% (according to 4, 3.5 mm I.D.) and 0–10% lower than standard, andCole tubes, respectively. The RWOB’s of virtual infant intubated with coneand Cole tubes were comparable and 10% lower with a standard tube. Con-

clusions: Intubation of a virtual infant with the cone and Cole tubesdecreased the flow resistance and RWOB. Intubation with the cone tube ofgentle shape should be associated with lower number of periglottic trauma,compared to the Cole tube. The work has been supported by the Founda-tion for Polish Science.

P 169 FUNCTION COURSE OF THE RETENTION TIME INHOLLOW FIBER BUNDLESA. Kashefi, B. Oedekoven, K. Mottaghy. Dept. of Physiology, RWTH-Aachen, University Hospital, GermanyAim: As a first approach the flow through hollow fiber (HF) bundles e.g. inoxygenators can be ideally described as bulk flow and hom*ogenous con-centration. Due to phenomena as shunt flows and dead water zones occa-sionally occurring in practice when liquids pass the space outside thebundles a mathematically flow description is rather difficult and inaccurate.Non adequate perfusion leads to insufficient mass transport performancedue to non optimal retention time distribution (RTD). Therefore an exper-imentally detection of the RTD is necessary to construct, improve or tocheck quality of mass exchange devices based on hollow fiber bundles.Methods: An experimental set-up was developed for HF modules. It con-sists of a hard shell reservoir, a pump with pulsatile or non pulsatile modes,and the module. At the module inlet and outlet pressures and temperaturesare monitored continuously. The liquid at defined flow rates and known tem-perature is pumped through the system. The parameters are registered bya conventional PC and data processing program. Depending on specialdemands different liquids such as water, glycerol, plasma, whole blood areused. Based on pulse marking by hot or ice water the course of tempera-ture changes at the inlet and outlet are measured at various flow rates.Results: RTD is calculated by using the measured data. Afterwards the devi-ations from the desired RTD of the hollow fiber module are evaluated bymeans of the dispersion model. Conclusion: Calculated deviations togetherwith RTD deliver additional knowledges in combination to the pressuredrop registration of HF-devices (oxygenators etc.). The Beside qualitycontrol purposes knowledge of RTD and dispersion grade are a new toolfinding mathematical descriptions of hollow fiber modules for designing ofnew devices.

P 170 DEVELOPMENT OF A HIGHLY INTEGRATED EXTRA-CORPOREAL MEMBRANE OXYGENATOR–DESIGN AND PERFORMANCEA. Strauß1, D. Henzler2, H. Reul1†, U. Steinseifer1, T. Schmitz-Rode1. 1Chairof Applied Medical Engineering, Aachen University, 2Anaesthesia Clinic,University Hospital Aachen, GermanyBackground: Extracorporeal membrane oxygenation (ECMO) should beable to support patients with acute respiratory distress syndrome (ARDS)for weeks or more. But these systems, consisting of basic components liketubes, pump, oxygenator, and heat exchanger, have high priming volumesand large blood contact surfaces and thus entail the risks of hemolysis,thrombosis, bleeding complications, and plasma leakage. It is at this pointthat the previously mentioned disadvantages can prove crucial. Moreover,handling of ECMO is very extensive. Aim: Our project is aimed to mini-mize the components of a ECMO system and to integrate them altogetherinto a small, compact device with reduced blood contact surface and lowpriming volume, minimizing above mentioned disadvantages. Methods: Aminiaturized, reusable rotary blood pump is placed into the center of anoxygenator. This particular configuration allows a compact design withoutheat exchanger. In vitro experiments with porcine blood have been carriedout to evaluate functionality and performance of this highly integratedextracorporeal membrane oxygenator (HEXMO). Results: The integratedblood pump ensures sufficient blood flow at relevant pressures. Due to con-vective heat exchange between blood pump and blood stream heat loss tothe environment is compensated. The Hemolysis of the HEXMO systemlies within physiological ranges. The particular gas- and blood flow path pro-vides efficient gas transfer. Conclusion: HEXMO presents a promising,manageable and economical ECMO system. The compact design enablessafe and sure operation as well as convenient handling, especially in criticalsituations. Future activities will be related to in vivo testing and furtherdesign improvements.

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P 171 CONVENTIONAL VERSUS DIFFERENTIAL VENTILATIONOF OLDER PATIENTS WITH HEALTHY LUNGS IN THE LATERALPOSITION-COMPARISON WITH THE USE OF VIRTUAL LUNGST. Golczewski, M. Darowski. Centre of Excellence ARTOG, Institute ofBiocybernetics and Biomedical Engineering PAS, Warsaw, PolandBackground: Smallest bronchiole are the part of the lung tissue and thustheir diameter depends on lung volume. If the volume is smaller than theclosing capacity (CC), bronchiole practically close the lung. CC increaseswith age. If it starts to be comparable with FRC, a lung, esp. the lower, i.e.dependent lung (DL) in the lateral position (LP), may be closed at the end of each expiration. Aim: analysis of total and each lung ventilation in hori-zontal position (HP) and LP. Method: Pressure (PCV) and Volume (VCV)controlled ventilations were used for virtual lungs simulating older patient(increased CC). Results: Despite that ventilation was adjusted correctly inHP and total ventilation might not change in LP, blood oxygenation fell dramatically in LP. During conventional PCV, DL either did not open oropened for too short time. VCV was much worse: independent lung (IL) hadto “work” to open DL for a short time and then a part of effete air movedfrom IL to DL, which had to decrease significantly total blood oxygenation(perfusion is greater in DL). Although PEEP improves DL ventilation, itforces IL too much. Differential ventilation, causing that ventilation of onelung was independent of another lung ventilation, improved significantlyeffects of ventilation. PEEP only for DL made ventilation of both lungsentirely correct. Conclusion: It seems the differential ventilation has to beused for all older patients being in LP; otherwise IL has to be ventilated toointensively, which causes baro- or volutrauma hazard. The work was done inthe frame of Eureka project E!3126 MULTIRESPI.

P 172 LUNGS VENTILATION HYBRID SUPPORT (LVHS) CONCEPTAIMED AT EASING THE NOCTURNAL MOTORIC DEFICIENCYM. Pokora, M. Darowski, J. Glapinski. Bioflows Dept, Institute Biocyber-netics Biomed Eng, Warsaw, PolandBackground: Different requirements for optimal relief of the brain and theremaining body segments during nocturnal bio-restoration create systemicneuro-somatic conflict represented by health-threatening periods of relativeimmobility causing sleep motoric deficiency (SMD). Method: To reducesome awkward effects of the SMD phenomenon by exposing the humanbody to harmonic motion—a motorized hybrid system for sleep oscillatorystimulation (SOS) is under investigation. Results: Reports reviewed confirmlarger number of sudden deaths and acute health crises linked to breathingand circulation that occur during the night, and in the morning, if comparedwith afternoon and evening fatalities. On the contrary, laboratory experi-ence with growth of cell cultures and with organs function in rabbits anddogs corroborates positive influence of rocking on condition of the biologictissue. Also clinically confirmed are assistive features of the rocking bedsused in polio, especially for breathing and quality of sleep due to apnea pre-vention. These findings may indicate that regular beds are too static tosecure equally safe regeneration of the whole body. Conclusions: Study sug-gests that the exposure to gentle, harmonic, rocking-like inertial impactsduring nocturnal body bio-restoration may bring health benefits to the user.The method may also prove to be helpful in states of long-lasting immobil-ity. Improvement in breathing, conditioning of functions of inner organs andnervous system, as well as reduction of sleeplessness may be achieved innorm and perhaps also in selected pathologies. The experimental device isbeing tested. Potential LVHS/SOS applications are in intensive care unitsas well as a new active bed for prevention, subject the individual acceptance.

Heart and Circulation Modeling

P 173 TIME RESOLVED PIV TECHNIQUE FOR HIGH TEMPORALRESOLUTION MEASUREMENTS OF PROSTHETIC HEARTVALVES FLUID DYNAMICSR. Kaminsky1,3, M. Rossi2, U. Morbiducci2,4, L. Scalise2, P. Castellini2,S. Kallweit3, P. Verdonck1, M. Grigioni4. 1Institute Biomedical Technology,Ghent University, Belgium, 2Universita Politecnica delle Marche, Ancona,Italy, 3ILA GmbH, Jülich, Germany, 4Technology and Health Department,Istituto Suepriore di Sanità, Rome, ItalyArtificial heart valves have been used since four decades to replace diseasednative valves and have saved millions of lives. Unfortunately, nowadaysthese devices are less than ideal and lead to many complications, many ofthem directly related to the fluid mechanics associated with the various

prosthetic valve designs. PIV measurements with high temporal resolutionis an accepted experimental tool to compare the quality of the blood flowacross heart valves. The evolution of the flow field downstream of two dif-ferent mechanical prosthetic heart valve (PHV) commercial models (abileaflet and a monoleaflet valve) was investigated in a mock-up by meansof the time-resolved 2D PIV technique. The combination of a Nd:YLF high-repetition-rate double-cavity laser with a high frame rate CMOS cameraallows the detailed, highly temporal resolved (up to 10000 fps depending onthe resolution) acquisition of the unsteady flow downstream of the twoinvestigated valve models. Our results show the monoleaflet valve charac-terized by a strong unsteady and asymmetric flow pattern, while the flowfield downstream of the bileaflet valve shows a more hom*ogeneous andsymmetric flow pattern leading to a lower degree of turbulence. The fluiddynamics of PHVs is particularly complex, with high spatial gradients andReynolds shear stresses, especially as far as mechanical heart valves are concerned. The fine-scale characteristics of such flows (e.g. turbulence pro-duction, vortex shedding, flow separation, stasis) calls for very accurateexperimental techniques, in terms of both spatial and temporal resolution.This last can be reached by applying time-resolved PIV. The highly tempo-ral revolved analysis we performed allows to study the evolution of the vor-tical structures in the flow field during the cardiac cycle and their survivaldownstream of the valve, with two wakes clearly visible downstream of thebileaflet valve, and a strongly inhom*ogeneous vorticity distribution for themonoleaflet model. It can be realistically expected that characterization ofthe new velocimetric techniques will help designers in improving PHV per-formance.

P 174 THE IMPORTANCE OF CORRECT GEOMETRY OFVENOUS ANASTOMOSIS AT VASCULAR ACCESS GRAFTS—PROVEN BY CFDU. Krueger, H. Scholz. Department of Vascular Surgery, Queen ElisabethHospital Berlin, GermanyBackground: The failure of arteriovenous grafts is often related to theirpoor hemodynamic performance, which leads to the development of anas-tomotic intimal hyperplasia. In an effort to address this topic, the Venaflovascular graft (BARD, Phoenix, Arizona, USA) was developed. The bulb-like shape of the venous end is the basic idea of the Venaflo. The positivefunctional properties of the Venaflo graft are closely connected with thecorrect design of the venous anastomosis. A not or wrong trimmed Venafloresults in a hooded anastomotic design. The hooded and a correct trimmedVenaflo anastomosis were compared. Methods: By using ComputationalFluid Dynamics (software CFX 5.6, ANSYS Ltd. USA), the flow patterns,static pressure and the wall shear stresses were calculated. As boundary con-ditions, the no-slip condition was assigned to all rigid walls. A time-depen-dent mass flow profile with Reynolds numbers of 1389 (systolic) and 648(mean) was specified as the inlet boundary condition. The distal outlet wasset to one third of the inlet mass flow; the velocity components at the prox-imal outlet were left free in order to obtain zero gradients of all variablesin the flow direction. The use of a non-Newtonian incompressible fluid con-sidered the effect of shear thinning. Results: In the hooded Venaflo anas-tomosis, the velocity levels near the floor are higher compared to the correctVenaflo anastomosis. A large region of boundary layer separation isobserved at the inner wall, the retrograde flow movement formed a vortexin both forms. The vortex is more developed in the correct Venaflo anasto-mosis. In general, very slow velocities in the hood region of the hooded anas-tomosis characterize the diastolic period. The velocity vectors of the highvelocity jet show the impact against the vein floor in hooded Venaflo. Here,the exposed areas as well as the duration of high wall shear stress are higher.On the other hand, the velocity vectors demonstrate the soft diversiontoward the proximal outlet in the correct trimmed Venaflo. Conclusions:The correct Venaflo graft performs significantly better, whereas the impactof the blood stream at the vein floor caused a stagnation point at the hoodedanastomosis. Risk of thrombosis occurring in the dead water regionincreases.

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P 175 HYDRODYNAMICS OF AORTIC CANNULAE DURINGEXTRACORPOREAL CIRCULATION: AN EVALUATION OF FLOWPATTERN AND SHEAR STRESS IN IN-VITRO MODELM. Minakawa1, I. f*ckuda1, J. Yamazaki2, T. Igarashi2, N. Funakoshi2,K. f*ckui1, H. Yanaoka2, T. Inamura2. 1Department of Surgery I, HirosakiUniversity School of Medicine, 2Department of Intelligent Machines andSystem Engineering, Faculty of Science and Technology, Hirosaki Univer-sity, Hirosaki, JapanBackground/Aim: Atheroembolism due to aortic perfusion is a critical com-plication in cardiovascular surgery using extracorporeal circulation (ECC).The objectives of this study are to visualize flow pattern in the aortic archduring the ECC, and to evaluate shear stress on the aortic wall. Methods:Two types of glass aortic arch models were made using optical modelingmethod based on the computed tomography image of a healthy adult manand the patient with aortic arch aneurysm. Water contained tracer was per-fused into the models at the rate of 4 L/min by a centrifugal pump throughthe aortic cannulae connected to the ascending aorta on these models. Flowpattern and velocity from the aortic cannulae were analyzed by particleimage velocimetry system. Additionally, strain rate tensor was visualized toestimate the magnitude of wall shear stress. Five different types of cannu-lae were evaluated: curved and straight end-hole cannulae, dispersioncannula and multiple jet-stream cannulae (SELECT 3D, Sarns Soft-flow).Results: Large vortices and helical flow were found in each cannula. Thehigh velocity (over 100 cm/sec) jet from the end-hole cannulae reached tothe arch vessels or posterior wall of the ascending aorta with the increasedstrain rate tensor. In the dispersion and SELECT 3D cannulae, cannular jetwas streaming along the inner curvature of the aortic arch, but neither highvelocity stream nor increased strain rate tensor was not found near the archvessels. In the Soft-flow cannula, strain rate tensor along the inner curva-ture and near the arch vessels was smaller than other cannulae. In the aorticarch model, neither increased rate of strain nor high velocity streamline wasobserved in dispersion or multiple jet-stream cannulae, while cannular jetfrom curved end-hole cannulae reached beyond the arch branches to thedistal aortic arch wall without attenuating. Conclusion: Multiple jet-streamcannulae was characterized with the lower shear stress on the aortic archwall, and will contribute to decreasing the prevalence of intraoperativestroke during the ECC.

P 176 TIME DEPENDENT CFD STUDY IN A THREE-DIMENSIONAL REALISTIC MODEL OF AORTIC ARCHC. Del Gaudio, U. Morbiducci, G. D’Avenio, M. Grigioni. Technology andHealth Department, Istituto Superiore di Sanità, Rome, ItalyBackground: A three-dimensional time dependent numerical simulation hasbeen carried out in a geometric model of aortic arch complete of a realis-tic aortic root and of the major branches in order to investigate the loca-tion of wall shear stress values relevant to vessels’ lesions and to analyzethe incidence of the implemented blood rheological models on vascular walldamage prediction. Methods: The aortic arch was modeled on the basis ofgeneral geometric features available in literature to take into account thedegree of curvature and the off-planarity shape. A plug time-dependentaxial velocity profile was imposed at the inlet section of the aortic root fora peak Reynolds number of 2200, based on the inlet diameter, and Womer-sley number of 20.4 Two different rheological models for blood were set andinvestigated, considering the evolving fluid as having a non-Newtonian anda Newtonian behaviour. Wall shear stress indices were calculated and com-pared, to evaluate differences in the prediction of the risk for the activationof pathways leading to atherogenesis. Results: Wall shear stress patternshighlighted high values in correspondence of the curvature of the aortic archand between the branch entrance locations, while velocity patterns resultedin highly skewed morphology in several transversal sections along the inves-tigated model. Moreover, averaged wall shear stress on selected regionsshowed lower values for the Newtonian case with respect to the non-New-tonian case; averaged oscillating shear index did not show significant dif-ferences for both blood models. Conclusion(s): The study here presentedshowed the model and a basic investigation of the fluid dynamics in theaortic arch and in its major branches. The complexity of the unsteady veloc-ity field in the vessels and the wall shear stress distribution along the modelgive the possibility to investigate particular regions prone to vascularlesions. Results could suggest a higher probability in the arterial wall injurypredicted by using a Newtonian model, based on the usually agreed assump-tion that vascular districts of high oscillating and low wall shear stress canbe prone to vascular lesions.

P 177 OPTIMALIZATION OF SURGICAL LEFT VENTRICULARRECONSTRUCTION IN PATIENTS WITH ISCHEMIC HEARTFAILURE USING MODELING METHODZ. Malota1, Z. Nawrat1,2, P. Kostka1, T. Kukulski3. 1Foundation of CardiacSurgery Development, Zabrze, 2Medical University of Silesia, Katowice,3Silesian Center of Heart Diseases, Zabrze, PolandDespite of significant improvement in the management of acute myocardialinfarction, congestive heart failure (CHF) remains one of the main reasonof the overall death in general population. CHF leads to the ventricularvolume increase and the change of shape from the elliptical one to circular.Surgical ventricular restorarion (SVR) has been developed lately in severalcardiosurgery centres around the world as an effective method of reducingthe volume and set up the proper shape of the left ventricle (LV) by cuttingor sewing up of the postinfarcted myocardial segments.The goal of thisproject is to elaborate the method of optimization of the surgical ventricu-lar reconstruction. This method will consist of in vitro examinations as wellas computer and physical simulations for individual patient based on hisdiagnostic data. During the period of project it should be possible to createthe expert–advisory system allowing individual and precise reconstructionof the left ventricle. This should also help a surgeon to plan the strategy ofreconstructive operation that may improve an outcome of patients postSVR. One of the project results is going to be computer environment fordiagnostic data analysis as well as 3-D heart models creating. The dynamicanalysis (tensions and myocardium movements) and blood flow computersimulation inside the ventricle will be carried out. Regional analysis of themyocardial wall deformation will be carried out using imaging data derivedfrom magnetic resonance (MRI) and ultrasound deformation (SRI) tech-niques. During the Menicanti procedure, the final left ventricular shape andvolume is is obtained by means of the balloon-sizer (Mannequin TM)inserted into the left ventricle. The above project will verify also this ven-tricular prototype and the methodology of patient/balloon matching.Finally, the modelling of shape, volume and dynamics of the left ventriclewill help more precisely and individually restore the damaged ventricle postmyocardial infarction and thus improve the early and long term results inischemic heart failure patients.

P 178 THE HEMOLYSIS TEST OF PULSATILE BLOOD PUMP,T-PLSH. Choi1,4,5, J.Y. Hong6, D.W. Lee6, K.H. Lee1,4,5, H.G. Yoon1,4,5

B.G. Min2,3,4,5,6. 1Interdisciplinary Program in Biomedical EngineeringMajor, Seoul National University, 2Department of Biomedical Engineering,College of Medicine, Seoul National University, Seoul, 3Institute of Medical Engineering, Medical Research Center, Seoul National University,4Korea Artificial Organ Center, 5Cancer Research Center, Seoul NationalUniversity Hospital, 6NewheartBio. Co., Ltd., Dongan-Gu, Anyang-Si,Gyeonggi-Do, KoreaAim: During heart surgery, a cardiopulmonary bypass pump is generallyused as a nonpulsatile blood flow generator such as centrifugal pump, biopump and roller pump. We developed a new pulsatile, portable cardiopul-monary bypass system (T-PLS, NewheartBio, Korea) which generates aphysiologic pulsatile blood flow without another device. It can also producea pulsatile flow by actuator pendulum speed (rpm) periodically. However,there is a problem that this pulsatile flow may induce added hemolysis as aresult of the repeated acceleration and deceleration of rpm. Methods: Thus,a hemolysis study of the pulsatile flow of the T-PLS was conducted. Con-forming to ASTM (American Society For Testing and Materials), three dif-ferent conditions were simulated: left ventricular assist device (LVAD),cardiopulmonary bypass (CPB), and percutaneous cardiopulmonary sup-port (PCPS). The beating rate of the T-PLS was set at 40 bpm, with repeti-tion of the same pendulum speeds being set to obtain the same average flowas that of the nonpulsatile mode. Results: The results were then comparedwith the nonpulsatile mode of the roller pump (Sarns 8000) and the non-pulsatile BioMedicus BP-80 (Bio-N) pump. The hemolysis results of the T-PLS were comparable to or better than those of the Bio-N, and no exces-sive hemolysis was observed, compared to the Sarns 8000. Conclusion:As a result of that, the T-PLS had an excellent hemolytic characteristic andgenerated no excessive hemolysis in most clinical usage conditions. In accor-dance with our experiences, these results suggest the effectiveness of thenewly designed pulsatile ECLS system to patients with severe cardiacfailure.

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Artif Organs, Vol. 29, No. 9, 2005

P 179 SYSTEM DESIGN FOR CPB & HF CONCURRENT TREAT-MENT WITH T-PLSJ.H. Mun1,4, K.M. Lim1,4, J.C. Lee1,4, B.G. Min2,3,4. 1Interdisciplinary Programin Medical and Biological Engineering Major, Graduate School, SeoulNational University, 2Department of Biomedical Engineering College ofMedicine, Seoul National University, 3Institute of Medical and BiologicalEngineering, Medical Research Center, Seoul National University, 4KoreaArtificial Organ Center, Korea University, Seoul KoreaBackground/Aim: Septic shock has high mortality in Emergency Room.Many methods are treated to prevent deaths of Septic shock. Fast removalof Endotoxin is necessary for recovery of patients by preventing Multior-gan failure. To reduce the mortality, nowadays concurrent treatment of CardioPulmonary Bypass (CPB) & Ultrafiltration (UF) are executed byMasanori Fujita et al. We designed different style blood line circuit for T-PLS (Twin Pulsatile Life Support) system and have tried to do CPB &Haemofiltration (HF) simultaneously with T-PLS. Methods: We made par-allel and countercurrent Sub-line for filtration. We tried 5 times. At first, weused Polyflux 6S Hemofilter (made by Gambro) two times. Next, we usedPan-06 Hemofilter (made by Asahi) two times. Last time, we installed flowcontrollers at front and back of filter. Results: When we did the Masanori’sstyle with T-PLS pump, we couldn’t get enough blood flow through filtra-tion part. So we made different blood line circuit for CPB & HF with T-PLS. It is based on the idea that we supposed Main Blood line from femoralvein to femoral artery is a natural blood line. We got too much (over 500 ml/min at total 1.2 L/min) Blood flow through Filtration part withPolyflux 6S. Because Filter’s resistance was lower than the blood inlet resis-tance and the Pump suction influenced Hemofilter. We got good Blood flow(200 ml/min) with Pan-06. And we could control the flow and Filtration ratewith installed controllers. Conclusion: We made and tested different styleblood line circuit for concurrent treatment of CPB & HF with T-PLS andcould control Ultrafiltration rate and ratio of Subline Blood flow (HF part)with small flow controllers. Most of all, this blood line circuit is more simplebecause we just use one pump. Simple system is essential in EmergencyRoom because rapid treatment can drop mortality. Acknowledgment: Thisstudy was supported by a grant of the Korea Health 21 R&D Project,Ministry of Health & Welfare, Republic of Korea. (02-PJ3-PG6-EV09–0001)

P 180 BLOOD FLOW ESTIMATION OF PULSATILE EXTRACO-POREAL LIFE SUPPORT SYSTEM WITH MINIMAL MEASURE-MENT AND MATHEMATICAL MODELINGS.W. Choi1,4, K.W. Nam1,4, K.H. Yoon1,4, S.M. Lee1,4,5, B.G. Min 2,3,4,5. 1Inter-disciplinary Program in Biomedical Engineering Major, Seoul National Uni-versity, 2Department of Biomedical Engineering, College of Medicine, SeoulNational University, 3Institute of Medical Engineering, Medical ResearchCenter, Seoul National University, 4Korea Artificial Organ Center, 5CancerResearch Center, Seoul National University Hospital, KoreaBackground/Aim: The pulsatile Extracorporeal Life Support System, T-PLS, has high pulsatility in outflow and high internal compliance to reducepressure change at its inlet port. Its mechanism is similar to human heartand brings 10% energy equivalent pressure (EEP) increment in in-vivoexperiment. But, high pulsatility and compliance of T-PLS make the esti-mation and control of its outflow difficult. Because, the pulsatile blood flowcan cause momentary low venous pressure and abrupt vein collapse. Inaddition, the high internal compliance of T-PLS can decreases the negativeinlet pressure that induces blood inflow from the patient’s vein so that theinflow can be decreased according to the decrement of patient’s venousreturn amount and venous pressure. the mathematical model of T-PLSinflow mechanism gives convenient method to estimate blood inflow.Methods: We constructed the mathematical model of T-PLS inflow mecha-nism and compared its results with that of in-vitro experiments. Results: InIn-vitro experiments, the venous pressure affected to the previouts flow esti-mation but, new flow estimation can expect the veinous pressure and com-pensate the effect of unknown venous pressure in the flow estimation.Conclusion: The inflow estimation was improved by the minimal measure-ment of inlet pressure and relationship between inlet pressure and operat-ing conditions.

P 181 EXPERIMENTAL VALIDATION OF COMPUTATIONALFLUID DYNAMICS BY THE USE OF OIL FILM METHODM. Stoiber1, S. Pirker3, C. Reindl1, L. Huber1, P. Gittler3, H. Schima1,2. 1Centerfor Biomed. Eng. and Physics, 2LBI for Cardiosurgical Research, Med. Univ.Vienna, 3Inst. of Fluid Mech. and Heat Transfer, J. Kepler Univ. Linz,AustriaAim: Today Computational Fluid Dynamics (CFD) is used for simulatingflow in many applications. The quality of the results however depends onvarious factors, like grid quality, boundary conditions and the computationalmodel of the fluid. For this reason, it is important to validate the accom-plished computation with experimental results. In this work a comparisonof numerical simulation with the oil flow method for different applicationswas performed. Methods: The investigations were accomplished at variousgeometries such as a bended tube and a magnetically levitated rotary bloodpump for the rotor vanes. The oil film for the experimental validation wascomposed of black oil color and varnish and applied with a brush. After adrying time of few minutes the measuring setup was filled with fluid andkept running for a short period of time. In the numerical simulation colorabrasion was displayed with a special post-processing tool by means of wallattached pathlines. Results: With proper choice of the numerical parame-ters, the computer simulations and the oil film method demonstrated goodcorrelation. For the pump impeller the calculation and the experimentshowed similar flow patterns with backflow and stall zones. Depending onthe flow rate it was necessary to adjust the viscosity of the oil color by addingmore or less varnish, to determine the amount of washed away oil film. Thetime of operation also influenced the clarity (i.e. intensity) of the flowpattern. Conclusion: The oil film method represents a fast and simpleapproach to validate numerical simulations of fluid flow. The experimentallygenerated near wall flow patterns can be easily compared with the solutionof the CFD Analysis.

P 182 NOVEL AND UNIFIED SOLUTION FOR HYBRID MODELSOF CARDIOVASCULAR AND RESPIRATORY SYSTEMSM. Kozarski*, G. Ferrari+, M. Darowski*, K. Górczynska*, C. De Lazzari+,K.J. Palko*,A. Tokarz*, G. Tosti+. *PAN Institute of Biocybernetics and Bio-medical Engineering, Center of Excellence ARTOG, Warsaw, Poland,+CNRInstitute of Clinical Physiology, Section of Rome, ItalyBackground/Aim: In mathematical models of cardiovascular and respira-tory systems their mechanical properties may be described by their imped-ances defined as a ratio of blood or air pressure drop and correspondingflow in any point of these systems. This approach gave rise to a family ofnew models defined as hybrid. The aim of this paper is to present someapplications of this method in cardiovascular and respiratory modelling.Methods: The hybrid models (numerical-physical) have been built as a con-nection of physically different parts: numerical—existing as a computerprogram and physical—built up of hydraulic, pneumatic and/or electricalelements. These physically different signal environments have beenmatched by special interfaces (impedance converters). Hybrid model devel-opment has been based on a mathematical model implemented as a numer-ical lumped model in a form of a computer program. Then a chosen sectionof the numerical model has been replaced by an equivalent physical section(hydraulic or pneumatic) of the same mechanical impedance, to permitassist devices testing. The electro-hydraulic and electro-pneumatic inter-faces (converters) have been made using electrically controlled flow andpressure sources. Results: The converters were tested separately: we foundthat accuracy of conversions is better than 1%. Linearity of both flowsources (pneumatic and hydraulic) as a function of control voltage is betterthan 0.1%. Two examples of application of the discussed hybrid models andsome experimental results (static and dynamic characteristics) have beenpresented. The hybrid circulatory system model proved to be suitable to theIABP investigations and the hybrid lungs simulator to respiratory supportstudies. Conclusions: The developed hybrid models are flexible, accurateand they enable modelling complex biological mechanical structures neces-sary in simulating different pathological cardiopulmonary conditions andthe corresponding mechanical support. In vitro verification of the modelsevidenced that they comply with the assumptions. Acknowledgments: Thework was sponsored by the Foundation for Polish Science (FNP) within theTechne Project.

Abbas S, O 118Abe Y, O 044, P 038, P 138Acocella3 F, P 133Adamczyk B, P 139Adami V, P 159Affeld K, O 013, P 017Afkhami F, O 040, P 010, P 027Agishi T, O 064Ahn CB, P 080Aigner R, O 008Akagawa E, O 046, P 163Akamatsu M, O 064Akdis M, O 047, O 071, P 073, P 082Akutsu T, O 029Albanesi F, P 143Alquist M, O 063Alvarado A, O 079Alves CM, P 126Alviano F, O 056Ambrosino G, O 022, P 094, P 116Ametani A, O 090Amitov V, O 059, O 060, P 050Anania G, P 121Ando J, P 147Andrè-Schmutz I, P 128Ansaloni L, P 129Antal A, P 005Antoranz JC, P 075Antosiak M, O 082Anzani T, P 133Aoki K, P 101Appl H, P 136, P 158Arabia M, O 125Arai H, O 045Arienti F, P 131Aruga M, P 074Arusoglu L, O 123Arvand A, O 028Asama J, O 045, O 049Asano E, P 063, 105Ascanelli S, P 121Ash SR, O 024Astori G, P 159Audzijoniene J, P 052Axelsson CG, P 052Azzena G, O 014, P 121

Bagnara GP, O 056Bagnoli P, P 133Bajraktarova T, P 048Bakir I, O 124Balducci A, P 044Ballat C, O 047, O 099Banasiuk E, P 100Baraldi O, O 117, P 009Baranska A, O 102Bardakhivskaya KI, P 031Barner L, O 107Bartl R, O 037Baselli G, P 077Basso S, P 094Basso SMM, P 116

Baudoin R, O 009Bauer A, O 013Bazika DA, O 091Becker C, P 008Belmonte G, P 143Beltempo P, P 084, P 089, P 091, P 092, P 122Belyaeva NV, O 091Berenguer I, O 035, O 048, O 079Berger G, P 076Bergmeister H, O 106Berlin G, P 052Berloco PB, O 019, O 026Bermejo J, P 075Bernardi M, P 122Bernath M-A, O 104Bertelli R, P 084, P 089, P 091, P 092, P 122Berzigotti A, P 112Bessa PC, O 088Bhathena J, O 040Bhattacharya M, P 127Bianchi F, O 056Bianchi F, P 109, 149Bianchi G, P 112, P 113Bianco A, P 151Bibiano L, P 022, P 029Bigi L, P 159Bocconcelli P, P 069Bogdanova M, O 059Boger ZO, 036Boldrin L, O 052, P 095, P 108 P 128,Bollen H, O 124Bollini S, O 087Bonasoni P, P 129Bondini S, P 108Bonofiglio R, P 060Borgnino L, P 087Borgnino LC, P 088, P 109Bortoluzzi F, P 028Bosch JP, O 063Bowlin G, O 086Bozzi M, P 023Brandt A, O 028Breymann C, O 051Brogli M, O 014Brolese A, P 094Brown JW, P 015Büter T, P 034Bujok W, O 001Bulmus V, O 107Burra P, P 118Buscaroli A, O 080Busi N, P 089Bussotti A, O 026

Cacici G, P 046Caenazzo L, O 022Calabrese F, P 118Campi C, P 085Canese R, P 068Cangini G, P 085del Cañizo A, O 048Canonico V, P 144

Cantoni S, O 056, P 149Cao H, P 103Capocasale E, P 089Cappuccilli ML, P 057, P 083, P 088, P 091, P 109,

P 149Caraceni P, P 122Cariani A, O 014, P 121Carli M, O 087Caroli E, P 143Carr DJ, O 024Carraro P, O 022, P 094Casagrande G, P 062, P 131Casal M, O 088Cassinelli C, O 108Castellini P, O 006, P 173Castello F, O 087Catapano G, P 060Catena F, P 129Catizone L, P 043, P 046, P 047Cavalcanti S, O 113Cavallari A, O 014, P 092, P 122Cavallari G, P 084, P 092Cavallesco G, P 121Cavallini C, O 056, P 149Cavazzana M, P 128Cenacchi A, P 148Centoni P, P 052Cerreta V, P 108Chamuleau R, O 010Chamuleau RAFM, O 012Chan Y, O 107Chang S, P 007Chassot P-G, O 104Chen H, O 040, P 010Chen HM, P 027Chen J, P 103Chen Y, P 103, P 103Cheng X, O 076, P 117Cheng XD, P 119, P 120Chianese R, P 112, P 113Chiari-Grisar C, P 125Chiarini A, O 117, P 009Chiavegato A, O 087Chieco P, P 108Chinzei T, P 038, P 138Choi H, P 011, P 032, P 040, P 178Choi SW, P 036, P 058, P 071, P 180Chung J, P 071Cianciolo G, O 117, P 009, P 057Ciandrini A, O 113Ciechanowska A, O 021, P 056Cikirikcioglu M, O 054, O 086, O 089, P 005,

P 018, P 019Cikirikcioglu YB, O 086, P 019Cilli M, P 159Cillo U, P 094, P 118Cimetta E, O 052de Cindio B, P 060Cipolli C, P 085Ciszowski K, P 096Cobaugh D, O 123Coen G, P 044

Author Index to Abstracts

Artificial Organs29(9):788–793, Blackwell Publishing, Inc.© 2005 International Center for Artificial Organs and Transplantation

788

AUTHOR INDEX TO ABSTRACTS 789

Artif Organs, Vol. 29, No. 9, 2005

Colacino F, O 125Coli L, O 117Colì L, P 009, P 057, P 095Colombo R, O 094Comai G, P 087, P 088, P 109Conconi MT, P 160Condò S, O 094Conte D, P 083, P 087, P 088, P 091Conte MM, P 046Contrusciere V, P 146, P 151, P 157Corbucci G, P 069Corradini S, O 026Correlo VM, P 127Costantino ML, P 062, P 077, P 131, P 133Coward SM, O 009Crawford A, P 127Cucchi C, O 094Cummings I, O 050Cwalina B, P 016Cybulski G, P 041Czarnowska E, O 109Czyzewska K, O 058

D’Addio F, O 080, P 090D’Amico D, O 022, P 094D’Amico DF, P 116D’Antiga L, O 022D’Avenio G, P 067, P 068, P 079, P 141, P 176Da Cruz S, P 005, P 018Dalla Valle R, P 089Dallari D, P 148Damjanovski M, P 048Damm E, O 036Darlak M, O 066, O 068Darowski M, O 031, P 041, P 139, P 164, P 168,

P 171, P 172, P 182David B, O 009Davis T, O 107De Angelis S, P 021, P 025, P 044De Carlo E, P 160De Coppi P, O 052, P 128De Lazzari C, P 182De Melis M, P 037, P 069De Smet R, O 033, O 061Debowska M, O 119DeCoppi P, O 087Degrassi A, P 159Dejanov P, O 020Dejanova B, O 020Del Cañizo JF, O 035, O 048, O 079Del Gaudio C, P 067, P 141, P 146, P 151, P 157,

P 176Delay D, O 104Derzsiová K, P 049Desco MM, P 075Dessì M, P 021Dessì MR, P 044Destro R, P 128Dhondt A, O 033, O 095Di Benedetto G, P 141Di Foggia M, P 006Di Giancamillo M, P 133Diana L, P 004, P 025Dimova B, O 081, P 086Ditadi A, P 128Doi K, P 154Doll N, O 121Domenicali M, P 122Donati G, O 117, P 009, P 057Donisi S, O 030Dorge H, O 047, O 099Drews T, O 122

Driesch D, O 011Du W, P 103Dumler F, O 057, O 098Dzekova P, O 018, O 060, P 045, P 050Dzikova S, O 081, P 086

Eder C, O 037, O 083, P 014, P 125, P 136,P 158

Effimova EA, P 117Efremov G, P 045Efremov GD, O 018Eguchi M, O 101Ehrmann A, O 021El-Banayosy A, O 123Eliasson G, O 062Elinson VM, O 111Eloot S, O 010, O 033, O 061, O 095Elvassore N, O 052Endo K, P 104Ercolani G, P 090Everaerts F, O 003

Fabbian F, P 043, P 046, P 047Fabbri M, P 143Fabietti PG, P 144Facchini A, P 159Faenza A, O 080, P 084, P 089, P 090, P 091,

P 092Faenza S, O 014, P 090fa*gnano C, P 006Falasca E, P 159Falaschini A, P 087Falkenhagen D, O 025, O 092, P 056Falkner E, O 037Falkner E, O 083, P 014, P 125, P 136, P 158Fallacara RA, P 042Falzano L, P 146Fang YF, P 080Fasano L, P 143Fata P, P 060Fattori R, P 009Feliciangeli G, O 080, P 087, P 090Feltracco P, P 094Ferrannini M, P 021Ferrari G, P 182Fierro A, O 094Filipovic N, O 114Filippini P, P 146, P 151, P 157Filkovska K, P 048Fini M, O 108Fiore GB, P 133Fiorentini C, P 146Flachi M, P 057Flaibani M, O 052Foltynski P, P 107Fornasari PM, P 148Fossati V, O 056Franceschini L, P 046Franchin E, O 022Frascà GM, P 022, P 029Freddi P, P 022, P 029Fruttini D, P 144Fuga G, P 084, P 089Fujimoto T, P 033, P 074f*ckuda I, P 175f*ckuda S, P 104f*ckuda T, O 029f*ckui K, P 175f*ckumoto A, P 154Fumero R, P 062, P 077, P 131, P 133Funakoshi N, P 175Funatsu K, P 101, P 102

Gabel G, P 017Gabriele D, P 060Gaffi G, P 022, P 029Gagliardi S, P 129Galach M, O 116Galato R, O 113Galli F, O 033Gamba PG, O 052Gasanov E, O 115Gautier A, O 009Gawlikowski M, O 066, O 068Gawlikowski T, P 096Gazzotti F, P 129Gelev S, O 059, O 060, P 048, P 059Genoni M, O 050Gerlach JC, O 011Gerunda G, O 014Ghodsizad A, O 077Giacometti C, P 118Giancaspro V, P 023Giannini R, P 108Giardino R, O 108Giavaresi1 G, O 108Ginanni Corradini S, O 019Giron GP, P 094Gittler P, P 181Giunti A, P 148Giuseppe S, P 093Gladkikh VYu, P 145Gladkikh YuV, P 145Glapinski J, P 168, P 172Glasmacher B, O 003, O 077, O 085Górczynska K, P 182Gössi M, O 051Godlewska E, O 082Goebel WW, O 015Golczewski T, P 171Golding L, O 123Gong X, O 076, P 117Gong XB, P 119, P 120Gorczynska K, P 041Goto H, P 020Gotoh M, O 038, P 007Goubergrits L, O 013Grabein K, O 027Gramantieri L, P 108Grazi GL, P 112Graziani R, P 112Greß S, P 134Grigioni M, O 006, P 037, P 067, P 068, P 069,

P 079, P 137, P 141, P 146, P 151, P 157, P 173,P 176

Gringeri E, P 118Griskevicius A, P 052Großherr M, O 105, P 034Grobovoy SI, P 115Grossmann M, P 070Grozdanovski R, O 059, O 060, P 050, P 059Gruber R, O 067Guariso G, O 022Guc M, P 139Guido I, O 013Guillevin L, P 051Guldner NW, O 105, P 034Guthke R, O 011

Haditsch B, O 008, P 124Hagiwara A, O 039Hagiwara A, P 152, P 156Hajjar R, O 055Halim T, O 040, P 027Halwachs G, O 053

790 AUTHOR INDEX TO ABSTRACTS

Artif Organs, Vol. 29, No. 9, 2005

Hamada S, O 046Hamasaki M, O 100Hamilton K, O 004, P 067, P 079Hansen C, O 105Hartmann J, O 025, P 056Hatton PV, P 127Hauser O, O 053Hayashi N, O 120Hayashida K, O 073, O 074, P 013, P 154Hegbrant J, O 063Heidland A, P 110, P 111Heizmann WR, O 036Hellevuo K, O 092Hendriks M, O 003Hengstler J, O 013Henseler A, O 075Henzler D, P 170Heschel I, P 008Hess OM, P 005Hessel F, O 027, P 097, P 134Hetzer R, O 036Hetzer R, O 122Higa M, P 033Hirasawa H, O 017Hirzinger G, O 030, O 067Hodgson HJF, O 009Hoekstra R, O 012ho*rstrup SP, O 050, O 051Hoffman AS, O 107Holdener S, O 050Holzer H, P 124Homma A, O 046, O 055, P 035, P 163,

P 165Homma D, P 033Hong JY, P 178Honma D, P 106Hori Y, P 020, P 106Horie T, O 042Horisberger J, O 104Hormes M, O 028Hormes M, P 073Horst U, O 028Hoshi H, O 045, O 049Huang H, O 073, O 074, P 147Huber L, O 106, P 181Hunt JA, P 126Hwang CM, O 065, P 080Hydzik P, P 096

Iberer F, O 053Ichihara S, P 104Igai H, O 038, P 007Igarashi T, P 175Iguchi A, P 138Ikada Y, P 152Imachi K, O 044, P 038, P 138Inada Y, P 104Inagaki A, P 020Inamura T, P 175Inoue T, P 154Ishibashi T, P 013Ishibashi-Ueda H, P 012Ishihara K, O 101, P 101, P 102Isoyama T, P 038Itoh H, P 147Itoh S, P 033Itoi S, P 104Ivanov AA, P 003Ivanovski K, P 048Ivanovski N, O 081, P 086Iwaoka W, O 046Iwasaki K, O 072, O 101

Jabbari E, O 084Jachertz M, O 104Jakse G, P 008Janakievska P, P 048Jank G, P 135Janke A, O 085Jarosz A, O 001Jegger D, O 104Jeong GS, O 065, P 080Jeong JH, O 034, P 061Jonsson P, O 062Jordanovski D, P 048Juettner W, P 070Jung A, P 124Jung MW, O 065Jung MW, P 080Junge G, P 098Jurmann M, O 122

Kabei N, P 074Kahn JM, P 162Kajiwara T, P 101, P 102Kakuta Y, O 046, P 163Kalajdziska M, O 018Kalangos A, O 054, O 086, O 089, P 005, P 018,

P 019Kallweit S, O 006, P 078, P 173Kaminsky R, O 006, P 078, P 173Kanda K, O 073, O 074, O 090, P 147, P 153,

P 154Kang JS, O 065Kansaku R, O 046, O 055, P 163Kapeller B, O 103, P 155Kapis A, O 001Karbasi S, P 001Karceva-Sarajlia E, P 048Karnafel W, O 021Kashefi A, P 169Katagiri N, O 046, P 163, P 165Katenz E, O 076, P 120Katenz EA, P 119Kawai T, O 072Kawamura A, O 042Kawiak J, O 021, P 100ka*wk YT, P 080Keding B, O 105Kertzscher U, O 013, P 017Khabiri E, P 005, P 018Khazai N, O 098Kholodkova EL, P 130Khrupachev O, O 115Kido K, O 043Kim C, O 004Kim JC, P 140Kim JH, O 034, O 112, P 011, P 061, P 167Kim KH, P 080Kin S, O 039, P 152, P 156Kinasiewicz A, P 100Kirkovsky VV, O 016Kirschkamp T, O 015Kitamura M, O 043Kitamura S, O 046, O 055, P 035Kizner L, O 123Klapproth P, O 105, P 034Klein D, O 092Klein M, O 077Knapp E, O 092Ko HJ, P 140Kobras K, P 111Koerfer R, O 123Kohler S, P 098Kohori F, P 166

Kojic M, O 114Konno S, P 033, P 138Korach JM, P 051Korczak A, O 066Korol VN, P 053Korolik AK, O 016Kostka P, O 069, O 070Kostka P, P 132, P 177Kouno A, P 038Kovacs L, O 085Kovalenko OA, O 091Kovalenko ON, P 145Kovaliv YB, O 097Kozarski M, O 031, P 041, P 182Kozinets GP, P 145Kramm K, P 078Krings M, O 003Krisper P, O 008Krisper P, P 124Krivohizhina LV, P 054, P 114Krueger U, P 174Krylov SE, P 003Krylova EA, P 003Krzymien J, O 021Kukita K, O 042Kukulski T, P 177Kulikov N, O 115Kuraszkiewicz B, P 164Kurenkov EL, P 115Kuriu Y, O 039Kuriu Y, P 156Kuryleva OM, O 110Kushibiki T, P 007Kustosz R, O 001, O 066, O 068, O 109Kusumi T, P 102Kuwabara T, P 064Kuznetsova EG, O 110Kwant PB, O 007

Lachmann N, O 121Lackner C, O 053Lackner JM, O 109Ladyzynski P, O 021, P 107Lai Q, O 019Lakner U, P 110La Manna G, P 088, P 091, P 109, P 149Lameire N, O 033Lanci N, P 109Landini S, P 028Landrath J, P 070Lanzarone E, P 077Laschka B, O 030Läufer T, P 008Lauro A, P 113Lee DW, P 032, P 040, P 178Lee H, P 163Lee HS, O 046Lee JC, P 179Lee JJ, O 065, P 080Lee K, O 034Lee KB, O 065Lee KH, P 024, P 032, P 040, P 178Lee KK, O 096Lee KS, O 112, P 011, P 061Lee SM, P 036, P 058, P 180Legallais C, O 009Leistner A, O 025Lekovski L, O 081, P 086Leunens V, O 124Li J, P 099, P 103Li L, P 103Li LL, P 099

AUTHOR INDEX TO ABSTRACTS 791

Artif Organs, Vol. 29, No. 9, 2005

Licursi M, P 084, P 092, P 122Liepsch D, O 030, O 067, P 076Lim KM, P 140, P 179Lindholm B, O 116, O 119Linsberger I, O 025Liu H, P 033Liu HJ, P 106Liumbruno G, P 052Liviano D’Arcangelo G, O 080Lledó-García E, O 079Lobacheva GA, O 016Lobyntsev DV, P 145Lobyntseva GS, P 145Lodi CA, O 113Loke F, O 036Lora S, P 151, P 157, P 160Losert UM, O 083, P 014, P 125, P 136, P 155, P

158Lovásová E, P 049Lozupone VA, P 023Luciani R, P 055Luck W, O 023Lukash LL, O 091, P 145Lupo A, P 046Luseva V, P 048Luyten P, O 124

McNeil K, P 072Macfelda K, O 103, P 155Maczinowski P, P 034Maeda T, P 106Maffei P, P 160Magosso E, P 095Major B, O 109Major R, O 109Makarov EV, P 054, P 114Malacarne F, P 043Malangone W, P 159Malerba A, O 052Mallabiabarrena I, P 026Malota Z, O 070, P 177Malysheva AM, P 115Mambrini G, P 159Mann H, O 118Manni M, P 044Mantella D, P 044Mantovani V, P 112, P 113Marangoni R, P 093Mareels G, O 010Marques A, P 126Marte W, P 162Martelli S, O 019, O 026Martin M, O 047, O 071, P 073Martinez C, O 079Martini C, P 160Martoni C, P 027Maruyama S, P 063, P 105Masiero L, P 128Masin-Spasovska J, O 059, O 081, P 086Massi Benedetti M, P 144Masumoto N, P 033Mateus M, P 161Matovic S, P 048Matsuda K, O 017Matsuda T, O 044, P 163, P 165Matsuki H, P 106Mattarozzi K, P 085Mazzocchi A, P 131Mazzoni MP, P 089Medart D, O 002, O 007Meguro J, O 042Meissner J, O 037

Menè P, P 055Mennini G, O 019Messina C, O 052, P 128Meyns B, O 124Mezzopane D, O 117, P 057Michnikowski M, P 168Mickel M, O 037Migalska-Musial K, P 107Miglietta F, P 062Mikhalovsky SV, P 002Mimaki A, O 044Min BG, O 034, O 096, O 112, P 011, P 024,

P 032, P 036, P 040, P 058, P 061,P 071, P 140,P 178, P 179, P 180

Mina GD, P 088Minakawa M, P 175Miotto D, O 022Mirzadeh H, O 078, O 084, P 001Misaki N, P 007Miscia MC, O 113Mitamura Y, O 043, O 044Mitsumune N, P 038Mitzner S, P 097Miura H, P 033Miura Y, P 013Miyawaki F, O 100Mizumoto H, P 101, P 102Mizuno T, O 046, O 055, P 035, P 163, P 165Mocchi CM, P 133Mochizuki S, P 038, P 138Mohammadi Y, O 078, O 084Mohr FW, O 121Mokvist K, P 052Mol A, O 051Molino C, P 047Monaco A, P 133Montalti R, P 084, P 089, P 092, P 122Morabito V, O 026Morbiducci U, O 006, P 037, P 065, P 067, P 069,

P 079, P 137, P 141, P 173, P 176Morettini M, P 144Moriyama Y, O 072Morosetti M, P 044Morra M, O 108Morshuis M, O 123Moscato F, O 125Mosconi G, O 080, P 083, P 085, P 087, P 090,

P 091Mottaghy K, O 075, P 135, P 169Moztarzadeh F, O 078, O 084Müller HM, P 162Mucciolo A, P 026Mucciolo G, P 026Mueller J, O 103Mukaibayashi H, O 046Mun CH, O 034, P 061Mun JH, P 179Mundy JL, P 127Mydlík M, P 049

Nagatoshi J, P 033Nagaya N, O 055Nakada A, P 104Nakagawa H, P 038Nakamura M, O 017, O 049Nakamura T, O 039, P 104, P 152, P 156Nakano S, P 074Nakano Y, P 020Nakase Y, O 039, P 150, P 152, P 156Nakashima S, O 039, P 152, P 156Nakayama Y, O 041, O 073, O 074, O 090, P 012,

P 013, P 035, P 147, P 153, P 154

Nakazawa K, P 101, P 102Nam KW, P 071, P 180Nannini L, O 094Nardo B, P 084, P 089, P 091, P 092, P 122Naruse K, P 123Naso A, P 094Naticchia A, P 021, P 044Nawrat Z, O 069, O 070, P 016, P 132, P 177Nehrer S, O 083, P 014, P 125Nemoto I, O 044Nemoto Y, O 073, P 035, P 147Neskovski J, P 048Neuenschwander S, O 050, O 051Neuhaus P, O 011, P, O 076, P 098, P 117, P 119,

P 120Neves NM, P 127Nicoli Aldini N, O 108Nicolino F, P 112Nigisch A, O 106Nikolaev AV, P 031Nikolaev VG, P 002, P 031Nikolov I, P 045Nilsson Sojka B, P 052Nishi S, P 012Nitta S, P 033, P 106, P 138Nobili M, P 137Noda K, P 101Norda R, P 051Nordien M, O 104Novelli G, O 019, O 026Novelli L, O 019, O 026Nozynski J, O 102Nozynski J, P 016Nüssler AK, P 117Nudo F, O 026Nussler AK, P 119

Occhionorelli S, P 121Oda S, O 017Oedekoven B, P 169Oertel H, O 030Ogawa D, P 033, P 138Ogon M, O 037Ohuchi K, O 045, O 049Ohzeki Y, O 072Okamaotoy Y, O 073Okamoto E, O 044, P 033Okamoto T, P 007Okamoto Y, P 012, P 013, P 035, P 147Okuno Y, O 064Olegario P, P 033, P 138Oliveira JT, P 127Ono T, P 038Orang F, P 001Orfao S, P 135Orlandi V, P 043, P 047Orlowski T, O 082Ortmann P, O 047, O 099Ortolani M, P 083, P 109Osikov MV, P 054, P 114Ota K, O 046, O 055, P 163, P 165Otsuji E, O 039, P 156Otten J, P 034Ouyang W, O 040, P 010, P 027Ozaki S, O 072

Palko KJ, P 182Pach J, P 096Pache J-C, O 054, O 086Pacil V, P 091Pacilè V, P 089, P 092, P 122, P 084Pacilli AMG, P 143

792 AUTHOR INDEX TO ABSTRACTS

Artif Organs, Vol. 29, No. 9, 2005

Palko KJ, O 031, P 041Palko T, P 041Palleschi S, P 004, P 025Pallotti G, P 066, P 142, P 143Pallotti MC, P 066, P 066Pan X, P 103Panzani I, P 159Papa V, P 025Pariali M, P 122Park JS, P 140Park JY, P 140Park Y, P 033Park YD, O 065Parnigotto PP, P 118, P 160Pascher A, P 098Pasic M, O 122Passerini G, P 112, P 113Pearcy MJ, P 072Peczkis G, O 066Pedemonte G, O 079Pedro AJ, O 088Perbellini A, O 056, P 149Perepelyuk NN, P 130Perkkiö T, O 015Persici E, P 009, P 057, P 149Pertosa AM, P 122Petrarulo F, P 023Petrovska T, P 048Petrusevska G, O 081, P 086Pettazzoni P, P 142, P 143Pfaff M, O 011Picardi A, P 116Piccari M, P 083, P 087, P 090, P 091Piccoli M, O 052, O 087, P 128Pidpala OV, O 091Piedimonte F, O 125Pierantozzi A, P 069Pierdomenico L, O 056Pieske B, O 099Pietraszek S, O 070Pikhtyeyev DM, P 130Pinna A, P 113Pinna AD, O 014, O 080, P 090, P 112Pirker S, P 181Plahchina IG, P 003Plebani M, P 094Pless G, O 011, O 012, O 076Podo F, P 068Pokora M, P 172Polaschegg H-D, O 032Polenakovic M, O 059, O 081, P 045, P 086Polenakovic MH, O 018Poli L, O 019Pompignoli E, P 113Ponzini R, P 137Popov Z, O 081, P 086Post H, O 099Poyck P, O 010Poyck PPC, O 012Pozzobon M, O 052, O 087, P 128Prakash S, O 040, P 010, P 027Predagostini R, O 019Pregla R, O 036Pretagostini M, O 026Przybylski R, O 102Ptak J, P 052Pugliese F, O 026Pulawska E, O 021Punzo G, P 055Pustelny T, O 068Puviani L, P 084, P 089, P 091, P 092Puviani P 122

Qin K, P 147Quaranta N, P 042

Rácz O, P 049Ragazzi R, O 014Raimondi C, O 117Raimondi C, P 057Ramlow W, P 051Ramunni A, P 042Ranieri G, P 042Rastan AJ, O 121Rau G, O 077Rawicz M, P 168Redaelli A, P 137Reindl C, O 106, P 181Reis RL, O 088, P 126, P 127Religa Z, O 102Remeeva EA, O 111Resta G, O 014, P 121Reul H, O 004, O 071, P 073, P 082, P 170Ria R, P 042Ricciatti AM, P 022, P 029Righini R, P 108Rinaldi M, O 123Ringe HIG, O 023Rock G, P 051Rodefeld MD, P 015Rodríguez-Martínez D, O 035, O 048, O 079Rogalski A, O 031, P 168Rojo JL, P 075Romei G, P 062Rosinski G, O 021Rossi B, P 004, P 025Rossi M, O 006, O 026, P 065, P 173Rossmanith E, O 092Roth S, O 012Rovdo IM, O 016Rozanova IB, O 111Ruberto F, O 026Rubizov YuP, P 145Russo M, P 043, P 047Russo V, P 009Rutkowski P, P 110Ruzmetov MM, P 015Ryabinin VE, P 115

Sabalinska S, O 021, P 056Saggioro A, P 028Saijo Y, P 033, P 106, P 138Saito I, O 044, P 038, P 138Saito J, O 029Saito S, P 035Sakai K, P 163, P 165, P 166Sakai O, O 090, P 153Sakakibara Y, P 064Sakakura C, O 039, P 156Sakhaeimanesh AA, O 005Sakota D, O 043Saliani MT, P 042Salimi S, O 075Salom S, O 035, O 048Salomatina LA, O 110Sankai Y, P 064Santini D, P 129Santoro A, O 014Sarnatskaya VV, P 002, P 031Sarti E, P 144Sartore S, O 087Sasada H, P 033Sato A, P 020Sato F, P 033Sato M, P 163, P 165

Sato T, P 153Satoh D, O 100Satoh F, P 106Satomi S, P 020Sauer I, O 023, P 098Sauer IM, O 012, O 076, P 117, P 119, P 120Scalise L, O 006, P 037, P 065, P 069, P 173Scarlata I, P 149Schaffellner S, O 053Scharfschwerdt P, O 013Schewior L, P 098Schildböck C, O 025Schiller W, O 030, O 067Schima H, O 106, P 181Schirmer R, P 034Schmallegger H, O 106Schmid J, O 076Schmid T, O 030, 067Schmid-Schönbein H, O 015Schmidt D, O 050, O 051Schmidt-Heck W, O 011Schmitto JD, O 047, O 099Schmitz C, O 007Schmitz-bode T, O 007Schmitz-Rode T, O 002, O 004, O 028, P 170Schneditz D, P 124Schnell-Inderst P, O 027Schöffl H, O 037, O 083, P 014, P 125, P 136,

P 158Schoendube FA, P 070Scholz H, O 093, P 174Schondube FA, O 047, O 099Schupp N, P 110Schwartlander R, O 012, O 076, P 117, P 119,

P 120Scolari MP, O 080, P 083, P 087, P 088, P 091,

P 109, P 149Scoletta P, O 014Sedelnikov N, P 005Seigneul I, O 104Sekine K, P 033, P 106, P 138Selden C, O 009Selezov I, P 142Selim Gj, P 059Selloni F, P 029Sergio S, P 047Sevastianov VI, O 110, O 111Severini G, P 004, P 025Severova G, P 050Sheng GP, P 099Shi W, P 038Shiga H, O 017Shigeta O, P 064Shim EB, P 011, P 140Shimokohbe A, O 045Shimosaki I, O 046Shin JS, O 096Shinshi T, O 045, O 049Shiokawa Y, O 120Shiomi M, P 012Shiraishi Y, P 033, P 106, P 138Sicolo N, P 160Sidorenko AS, P 031Siebert C, O 047, O 099Siebert U, O 027Sievers HH, O 105, P 034Sikole A, O 018, O 059, O 060, P 045, P 050Silva AI, P 161Silvestroni L, P 004Simjanovska L, O 018Simjanovska Lj, P 045Simon C, P 055

AUTHOR INDEX TO ABSTRACTS 793

Artif Organs, Vol. 29, No. 9, 2005

Simons AP, P 078Sipulová A, P 049Slanzi E, O 087, P 128Slavkovska A, P 045Solano L, P 029Son HS, O 096, P 080Song X, P 039Soverini ML, O 117, P 009Spasovski G, O 020, O 059, O 060, G, O 081,

P 048, P 059, P 086Splendiani G, O 094, P 004, P 021, P 025, P 044Stabellini N, P 047Stadlbauer V, O 008, O 053Stagni C, P 148Stankiewicz B, P 139, P 168Stauber R, P 124Stauber RE, O 008Stayton P, O 107Stefoni S, O 080, O 117, P 009, P 057, P 083,

P 084, P 085, P 087, P 088, P 090, P 091, P 092,P 095, P 109, P 149

Stegmayr B, P 052Stegmayr BG, O 062, P 051Steinseifer U, O 002, O 004, O 007, O 028, P 079,

P 170Stiegler P, O 053Stiller S, O 118Stock M, O 030Stoiber M, O 106, P 181Stojcev N, O 059, O 060, P 050Stopper H, P 110, P 111Storari A, P 043Strauß A, P 170Strom SC, O 022Sugino A, P 038Sukhov D, O 115Sullivan TA, O 024Sun K, O 065, O 096, P 071, P 080Szary B, O 058Szentivanyi A, O 077Szwast M, P 041

Tabata Y, O 038, P 007Tabayashi K, P 033, P 138Taddei P, P 006Taenaka Y, O 046, O 055, P 035, P 163, P 165Taffurelli M, P 129Tajima K, O 049Takada S, P 020Takahashi N, O 043Takahashi S, O 100Takano H, O 055Takano Y, O 100Takatani S, O 007, O 045, O 049Takeuchi Y, O 101Takewa Y, O 046, O 055, P 035, P 165Takiura K, P 138Tamagno G, P 160Tampieri E, P 009, P 057Tanaka A, P 033, P 138Tanaka H, P 163, P 165Tanaka T, P 033Taniguchi N, P 038Tatar T, P 005Tatsumi E, O 046, O 055, P 035, P 163, P 165Taub S, P 026Teatini U, P 062Tedesco A, P 066Tempesta D, P 028Thalmann D, O 105

Tille J-C, O 086, O 089, P 018, P 019, O 054,P 005

Timmel T, O 013Timms DL, P 072Todeschini P, P 083, P 085Toepfer S, O 011Tokarz A, O 031, P 182Tolpekin V, O 115Tomanovski V, P 048Tomat S, P 118Torrianni M, O 003Tosti G, P 182Tozzi P-G, O 104Travetti O, P 133Trpenovski L, P 048Tscheliessnigg KH, O 053, P 162Tsuda A, O 114Tsuda I, O 042Tsukiya T, O 046, P 035, P 163, P 165Tsung-Hua Y, P 030Tsuruhara Y, O 120Tsutsui T, P 064de Tullio D, O 014Turek A, P 015Turina M, O 051Turrentine MW, P 015Tylla A, O 047

Ueda-Ishibashi H, P 013Uematsu M, P 033Umezu M, O 044, O 072, O 101, P 033, P 074Unbehaun N, O 085Unit L, P 093Urban JPG, P 001Ursino M, O 117, P 095

Valieri L, O 014, P 121van Gulik TM, O 012van Wijk ACWA, O 012Vanholder R, O 033, O 061, O 095Varotto S, O 022, P 116Vassanelli C, P 046Vega A, P 044Ventura C, O 056, P 149Verdonck P, O 006, O 010, O 061, O 095, P 173Verdonck PR, P. 078Vettor R, P 160Vienken J, P 110, P 111Vigolo S, P 160Vitalba A, P 028Vitiello L, O 052Vittoria Gazzola M, P 128Vodermayer B, O 067von Segesser LK, O 104, P 026Vondran F, O 076Vondran FWR, P 117, P 119, P 120Voronin AV, P 145

Wachter R, O 099Waldhauser W, O 109Waldmann-Beushausen R, O 099Walpoth BH, O 054, O 086, O 089, P 005, P 018,

P 019Walther T, O 121Wang Q, P 033, P 106Wang Y, P 039, P 081Waniewski J, O 119Wasem J, O 027, P 097, P 134Wasler A, P 162Watanabe M, P 106

Watanabe T, O 073, P 020Waterloos MA, O 033Weber A, O 051Weber HJ, P 078Weber V, O 025Weigel G, O 106Welz A, O 030, O 067Weng Y, O 122Weryñski A, P 100Werynski A, O 116, O 119Wikström B, P 052Wilczek P, O 102Wittekind C, O 121Wojcicki JM, O 021, P 056, P 107Won YS, O 096

Yaku H, O 073, O 074, O 090, P 147, P 153, P 154Yamagishi H, O 039, P 152, P 156Yamamoto K, P 147Yamamoto Y, O 038, P 007Yamash*ta JK, P 147Yamazaki J, P 175Yambe T, O 044, P 033, P 063, P 105, P 106,

P 138Yanaoka H, P 175Yang D, P 117Yang S, O 054, O 089Yano T, O 043Yatsishina AP, O 091Yelskaya AV, P 145Ying C, P 039Ying CT, P 081Yokomise H, O 038, P 007Yokoyama Y, O 007Yonekawa M, O 042Yoon HG, O 112, P 011, P 032, P 040, P 178Yoon KH, P 036, P 058, P 180Yoshida M, P 074Yoshikawa M, O 049Yoshikawa T, O 039, P 156Yoshizawa M, P 033, P 138Yotti R, P 075Yu HY, P 099Yushko LA, P 031

Zafirovska K, P 059Zafirovska M, P 048Zancan L, O 022Zanesco L, O 052, P 128Zanetti A, P 090Zanon GM, O 087Zanow J, O 093Zanus G, P 094Zaporozhan VN, P 130Zappoli P, P 112Zardi E, P 116Zdravkovska V, P 048Zeilinger K, O 011Zembala M, O 102Zhang Y, P 103Zhang YM, P 099Zhou Y, O 041, O 090, P 013Zielinski K, P 139Zimmering M, O 023Ziolkowski B, O 021Zoli M, P 112, P 113zu Dohna R, O 122Zünd G, O 050Zund G, O 051Zvonareva O, P 142