bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemocompatibility in Hemodialysis and Erythropoietin Therapy
Authors: Opatrný Karel , Vít Ladislav , Opatrná Sylvie , Polakoviĉ Vladimír , Ŝefrna Frantiŝek , Sulková Sylvie , Opatrný Karel
Published: November 2008

Abstract: Two studies designed to investigate the effect of recombinant human erythropoietin (rHuEPO) treatment of anemia in chronic dialysis patients on hemocompatibility were conducted. Study 1, whose main aim was to establish whether treatment with rHuEPO enhances coagulation activation during dialysis, included 15 patients before rHuEPO therapy at a mean hematocrit (HCT) of 22.3% and then during therapy at a HCT of 29.3%. The plasma concentrations of the thrombin‐antithrombin III complex were not higher during rHuEPO therapy than before it when performing hemodialysis with a Cuprophan membrane. No significant difference was demonstrated either in the values of activated clotting times (Hemochron), thrombocyte or white blood cell counts (Coulter S + II), or in plasma C5a concentrations (ELISA) established during dialysis sessions before and during rHuEPO therapy. In Study 2, which focused primarily on the question of whether or not rHuEPO therapy increases thrombocyte activation during hemodialysis, 8 patients on chronic dialysis were examined both before therapy at a mean HCT value of 22.1% and during rHuEPO therapy at a HCT of 31.5%, invariably during dialysis with either a Cuprophan or polyacrylonitrile (AN69HF) membrane. The plasma concentrations of beta‐thromboglobulin (ELISA) did not differ between the examinations made during rHuEPO and before rHuEPO therapy; however, statistically significant differences were found between dialysis sessions involving Cuprophan and AN69HF membranes. No significant difference between examination before and during rHuEPO was demonstrated in activated clotting time nor thrombocyte and white blood cell counts in this study either. The authors conclude that rHuEPO therapy does not enhance coagulation activation during hemodialysis, does not have an effect on thrombocyte activation, and does not influence complement activation and changes in white blood cell counts.
Separation of the Natural Atria in Experimental Implantation of Total Artificial Heart
Authors: Frazier O.H. , Matsuwaka Ryousuke , Parnis Steven M. , Furusho Nobuyuki , McGee Michael G. , Fuqua John M.
Published: November 2008

Abstract: Atrial connections in a single‐unit total artificial heart (TAH) may be difficult to make because of the rigidity of the device and the fixed position of the atrial inlets. We developed a technique to separate the natural atrial borders in an experimental implantation of a unitary TAH. In this technique, the interatrial groove was dissected to separate the posterior wall of the right atrium from the roof of the left atrium before cardiopulmonary bypass (CPB) was initiated. After initiation of CPB and cardiectomy, the atrial septum was separated completely, and the right atrial wall was reconstructed with glutaral‐dehyde‐treated autopericardium. We believe that this simple adjunctive technique provides increased mobility of the atrial cuffs and allows for an easier connection of the unitary TAH.
A New Model for Evaluation of Biocompatibility: Combined Determination of Neoepitopes in Blood and on Artificial Surfaces Demonstrates Reduced Complement Activation by Immobilization of Heparin
Authors: Mollnes Tom Eirik , Riesenfeld Johan , Garred Peter , Nordström Eva , Høgåsen Kolbjørn , Fosse Erik , Götze Otto , Harboe Morten
Published: November 2008

Abstract: An in vitro technique was developed for assessment of the biocompatibility of materials for use in clinical applications. Artificial materials were exposed to blood, and the resulting complement activation was quantified both in the plasma and on the material surface by enzyme immunoassays based on monoclonal antibodies specific for neoepitopes exposed in complement activation products. Several materials were evaluated, and the effect of surface modifications, including end–point immobilized heparin, was studied. The results revealed widely varying complement activation properties of the different materials and confirmed that heparin markedly improves biocompatibility. The present method is superior to analysis limited to either the fluid phase or solid phase since certain materials adsorb activation products (exemplified by Tecoflex) whereas others do not although activation was evident from fluid–phase assay (silicone). Furthermore, direct determination of activation–specific neoepitopes on the surface represents an improvement compared with previously described methods for detection of adsorbed components.
An Immunohistochemical Analysis of Implanted Woven Dacron and Expanded Polytetrafluoroethylene Grafts in Humans
Authors: Urayama Hiroshi , Kasashima Fuminori , Kawakami Takuhisa , Kawakami Kengo , Watanabe Yoh
Published: November 2008

Abstract: An immunohistochemical analysis was performed to clarify the healing process in implanted vascular grafts in human. Eight woven Dacron grafts and 6 expanded polytetrafluoroethylene grafts were obtained following redo surgery, limb amputation, and autopsy. The implantation periods ranged from 5 days to 148 months. The antibodies used for the analysis were specific to a‐actin (smooth muscle cells), macrophages, von Willebrand factor (endothelial cells), fibrin, elastin, collagen types 1–5, CD3 (T cells), and CD20 (B cells). At 5 and 24 days after implantation, thrombi containing red blood cells and fibrin covered the anastomotic lines and some of the luminal surfaces of the grafts. Macrophages were scattered throughout the thrombi. At 11–148 months after implantation, either a single layer of endothelial cells or a thin layer of fibrin covered the anastomotic segments of the grafts, and smooth muscle cells and collagen fibers were seen forming anastomotic intimal hyperplasia (AIH). The AIH in the grafts at 94 and 148 months after implantation was almost the same thickness and length as that in the grafts at 11–36 months after implantation. Apart from the anastomotic segments, a connective tissue matrix containing collagen fibers covered the luminal surfaces, and some thrombi were noted. Most of the collagen present was type 3, in addition to some type 1, 4, and 5 collagen. No type 2 collagen was noted. Some elastin was also detected in the AIH but not in the midportion of the grafts. Some macrophages and T cells were noted in the perigraft tissues.
Bacterial and Fungal Infection in Neonates Undergoing Venoarterial Extracorporeal Membrane Oxygenation: An Analysis of the Registry Data of the Extracorporeal Life Support Organization
Authors: Douglass Brenda H. , Keenan Andrea L. , Purohit Dilip M.
Published: November 2008

Abstract: A review and analysis of 5,001 neonatal venoarterial (VA) extracorporeal membrane oxygenation (ECMO) cases showed that bacterial and fungal infection occurred in 147 (2.9%) and 26 (0.6%) patients, respectively, with an overall incidence of 3.5%. Bivariate analysis was used to compare infected infants with controls, bacterial versus fungal groups, and bacterial subgroups with respect to patient demographics, primary diagnosis, mechanical complications, patient complications, duration of the ECMO course, and hospital mortality. Logistic regression models were constructed using variables that were statistically significant from the bivariate comparisons. Variables that remained significant after multivariate analysis included primary diagnosis of pneumonia/ sepsis, mechanical complications of oxygenator failure, rupture of raceway or tubing, clots, and patient complications of hypertension and hyperbilirubinemia. The infection group had significantly longer mean total hours on bypass and higher hospital mortality. Infants with fungal infection had a significantly higher hospital mortality rate compared with those with bacterial infection. We conclude that infection during ECMO, especially fungal infection, carries an increased risk of hospital mortality and that mechanical complications are associated with an increased risk of infection.
Monitoring the Native Cardiac Output During Femoral Venoarterial Cardiopulmonary Bypass Support
Authors: Sakamoto Tohru , Arai Hirokuni , Shimizu Masato , Suzuki Akio
Published: November 2008

Abstract: To manage postcardiotomy patients with cardiopulmonary bypass support (CPS), it is very important to evaluate the native cardiac function. In 5 postcardiotomy cases without CPS, the alternative thermodilution outputs by right ventricular (RV) injection were compared with simultaneous thermodilution outputs by standard right atrial (RA) injection. Cardiac output determined by RV injections, ranging from 3.4 to 10.1 L/min, showed close agreement with the values by RA injections (r = 0.993). Four cases with postcardiotomy profound heart failure were placed on femoral venoarterial CPS and managed with monitoring native cardiac output determined by an RV injection thermodilution method. It was very easy and reasonable to decide the pump flow relative to native cardiac output. The cardiac output determined by RV injection provides a means of accurate evaluation for the failing heart in postcardiotomy cases with venoarterial CPS and optimizes the staged weaning off CPS or the change to a pneumatic pulsatile ventricular assist device for long‐term assist.
State of the Art of Lipid Apheresis
Authors: Bosch Thomas
Published: November 2008

Abstract: Currently, 5 different lipid apheresis procedures are available for routine clinical treatment of hy–percholesterolemic patients. Unselective plasma exchange is a technically simple extracorporeal circuit, but albumin substitution fluid must be used and there is no high–density lipoprotein (HDL) recovery. Semiselective double filtration with improved size selectivity because of a small–pore secondary filter combines good elimination of low–density lipoprotein (LDL), lipoprotein (a) (Lp[a]), and fibrinogen with adequate HDL recovery; modifications such as thermofiltration, predilution/backflush, or pulsatile flow have been proposed for the improvement of this system. Three highly selective procedures are basedon immunologic or electrostatic interactions: immunoad–sorption using anti–low–density lipoprotein (LDL) antibodies, chemoadsorption onto dextran sulfate, and hep–arin–induced LDL precipitation (HELP) apheresis. The features of each system are discussed critically. Lastly, two new developments, Lp(a) immunoadsorption and LDL hemoperfusion using a polyacrylate LDL adsorber compatible with whole blood, are described
Short–and Long–Term Effects on Serum Lipoproteins by Three Different Techniques of Apheresis
Authors: Richter Werner O. , Donner Markus G. , Schwandt Peter
Published: November 2008

Abstract: Low–density lipoprotein (LDL) apheresis is applied in patients with coronary heart disease because of severe inherited forms of hypercholesterolemia, for which dietary and combined drug treatment cannot lower LDL cholesterol concentrations less than 130 mg/dl. The following article describes the changes in lipoprotein levels in a total of 19 patients undergoing weekly LDL apheresis. Immunoadsorption, operating with polyclonal antibodies against apolipoprotein B–100, was used in 6 patients. Five patients were put on heparin–induced extracorporeal LDL precipitation (HELP) therapy; 6 received dextran sulfate adsorption treatments. Under steady–state conditions a single treatment reduced LDL cholesterol by 149 ± 3 m/dl with immunoadsorption, 122 ± 2 mg/dl with HELP, and 124 ± 18 mg/dl with dextran sulfate adsorption. Lipoprotein (a) (Lp[a]) declined by 52 to 65%. Very low density lipoprotein (VLDL) cholesterol and VLDL triglycerides declined by 45 to 55% because of the activation of lipoprotein lipase and precipitation during the HELP procedure. In all procedures, there was a small reduction in the different high–density lipoprotein fractions, which had returned to normal after 24 h. The long–term HDL3 cholesterol levels increased significantly. During all procedures there was a decrease in the molar esterification rate of lecithin cholesterol acyltrans–ferase activity. All changes in lipid fractions were paralleled by changes in the corresponding apolipoprotein levels. It is concluded that all three techniques described are powerful tools capable of lowering LDL cholesterol in severe hereditary forms of hypercholesterolemia. In HELP and dextran sulfate adsorption, the amount of plasma is limited by the elimination of other plasma constituents. Immunoadsorption may thus be preferred in very severe forms of hypercholesterolemia.
Application of Computational Fluid Dynamics Techniques to Blood Pumps
Authors: Sukuma Ramakrishnan , Athavale Mahesh M. , Makhijani Vinod B. , Przekwas Andrezj J.
Published: November 2008

Abstract Present‐day computational fluid dynamics (CFD) techniques can be used to analyze the behavior of fluid flow in a variety of pumps. CFD can be a powerful tool during the design stage for rapid virtual prototyping of different designs, analyzing performance parameters, and making design improvements. Computational flow solutions provide information such as the location and size of stagnation zones and the local shear rate. These parameters can be correlated to the extent of hemolysis and thrombus formation and are critical to the success of a blood pump. CFD‐ACE, an advanced commercial CFD code developed by CFD Research Corporation, has been applied to fluid flows in rotary machines, such as axial flow pumps and inducers. Preprocessing and postprocessing tools for efficient grid generation and advanced graphical flow visualization are integrated seamlessly with CFD‐ACE. The code has structured multiblock grid capability, non‐Newtonian fluid treatment, a variety of turbulence models, and an Eulerian‐Lagrangian particle tracking model. CFD‐ACE has been used successfully to study the flow characteristics in an axial flow blood pump. An unstructured flow solver that greatly automates the process of grid generation and speeds up the flow simulation is under development.
Prediction of Hemolysis in Turbulent Shear Orifice Flow
Authors: Tamagawa Masaaki , Akamatsu Teruaki , Saitoh Keijiroh
Published: November 2008

Abstract

This study proposes a method of predicting hemolysis induced by turbulent shear stress (Reynolds stress) in a simplified orifice pipe flow. In developing centrifugal blood pumps, there has been a serious problem with hemolysis at the impeller or casing edge; because of flow separation and turbulence in these regions. In the present study, hemolysis caused by turbulent shear stress must occur at high shear stress levels in regions near the edge of an orifice pipe flow. We have computed turbulent shear flow using the low‐Reynolds number k ‐ε model. We found that the computed turbulent shear stress near the edge was several hundreds times that of the laminar shear stress (molecular shear stress). The peak turbulent shear stress is much greater than that obtained in conventional hemolysis testing using a viscometer apparatus. Thus, these high turbulent shear stresses should not be ignored in estimating hemolysis in this blood flow. Using an integrated power by shear force, it is optimimal to determine the threshold of the turbulent shear stress by comparing computed stress levels with those of hemolysis experiments of pipe orifice blood flow.
Characteristics of a Blood Pump Combining the Centrifugal and Axial Pumping Principles: The Spiral Pump
Authors: Andrade Aron , Biscegli José , Dinkhuysen Jarbas , Sousa José Eduardo , Ohashi Yukio , Hemmings Sarah , Glueck Julie , Kawahito Koji , Nosé Yukihiko
Published: November 2008

Abstract: Two well‐known centrifugal and axial pumping principles are used simultaneously in a new blood pump design. Inside the pump housing is a spiral impeller, a conically shaped structure with threads on the surface. The worm gears provide an axial motion of the blood column through the threads of the central cone. The rotational motion of the conical shape generates the centrifugal pumping effect and improves the efficiency of the pump without increasing hemolysis. The hydrodynamic performance of the pump was examined with a 40% glycerin‐water solution at several rotation speeds. The gap between the housing and the top of the thread is a very important factor: when the gap increases, the hydrodynamic performance decreases. To determine the optimum gap, several in vitro hemolysis tests were performed with different gaps using bovine blood in a closed circuit loop under two conditions. The first simulated condition was a left ventricular assist device (LVAD) with a flow rate of 5 L/min against a pressure head of 100 mm Hg, and the second was a cardiopulmonary bypass (CPB) simulation with a flow rate of 5 L/min against 350 mm Hg of pressure. The best hemolysis results were seen at a gap of 1.5 mm with the normalized index of hemolysis (NIH) of 0.0063 ± 0.0020 g/100 L and 0.0251 ± 0.0124 g/100 L (mean ± SD; n = 4) for LVAD and CPB conditions, respectively.
Membranes in Artificial Organs
Authors: Schmidt Baerbel
Published: November 2008

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.
Lipid Apheresis: From a Heroic Treatment to Routine Clinical Practice
Authors: Bosch Thomas
Published: November 2008

Abstract: Lipid apheresis has developed from a heroic treatment into a routine clinical therapy and currently is the major indication for performing extracorporeal plasma therapy. Whereas it was once reserved for patients with homozygous familial hypercholesterolemia, today it has a place in the secondary prevention of severe coronary heart disease when low‐density lipoprotein (LDL)‐cholesterol levels exceed 150 mg/dl, despite conservative treatment, in any type of primary hypercholesterolemia. Unselective plasma exchange has been replaced by a variety of selective procedures. The efficacy of the treatment can be maximized by combining LDL apheresis with the use of cholesterol synthesis enzyme inhibitors. Clinical studies have shown that drastic cholesterol reduction can result in regression of coronary atherosclerosis as well as in reduced cardiac morbidity and mortality. Technical progress comprises improved selectivity, online regeneration of adsorbers, and LDL adsorption from whole blood. Recently, a new LDL hemoper‐fusion procedure was successfully tested in a clinical pilot study; blood is passed directly over a lipid sorbent without prior plasma separation. If this system is demonstrated to be safe and effective in clinical Phase III trials, a further qualitative step in the rapid development of LDL apheresis will have been made.
Microspheres Based Detoxification System: A New Method in Convective Blood Purification
Authors: von Appen Kai , Weber Christoph , Losert Udo , Schima Heinrich , Gurland Hans‐Jürgen , Falkenhagen Dieter
Published: November 2008

Abstract: A variety of protein‐bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high‐volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module‐based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high‐velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high‐flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.
Tubular Vacuum‐Powered Blood‐Pumping Device with Active Valves
Authors: del Cañizo Juan F. , Antoranz J. Carlos , Duarte Juan , Desco M. Mar , García‐Barreno Pedro
Published: November 2008

Abstract: We propose a new vacuum‐driven blood pump having a tubular shape with active valves. This design avoids any possible problems caused by membrane breakage, thereby minimizing the risk of gas embolic events and stagnation regions. By using active valves, it is possible to ensure better flow control and minimize pressure gradients inside and outside the pump. The low cost of the pump's disposable parts enables it to be used for such applications as a ventricular assist device, a pulsatile pump device in extracorporeal circulation, a pump in hemodialysis and apheresis circuits, and a pump in extracorporeal membrane oxygenator systems.
Determinants of Ammonia Clearance by Hemodialysis
Authors: Cordoba Juan , Blei Andres T. , Mujais Salim
Published: November 2008

Abstract: Ammonia toxicity appears to contribute to the genesis of brain edema, a leading cause of death in fulminant hepatic failure. Because dialysis has been recommended for acute hyperammonemia in other conditions, we have conducted a study to analyze the determinants of ammonia clearance with the use of a single‐pass dialyzer. We have used an ionic solution with a constant concentration of ammonia to estimate clearance at different blood flow rates, at dialysate flow rates, and with different dialyzer surfaces. Once hemodialysis had been optimized, we estimated ammonia, glutamine, and urea removal by using a single‐compartment model. Our results show that the clearance of ammonia is blood flow dependent and is also influenced by dialysate flow rate and dialyzer surface. At clinically feasible conditions, ammonia can be extracted by more than 80% by setting the dialysate flow at a high rate. In addition to ammonia removal, hemodialysis allows the clearance of urea and glutamine, molecules that can be regarded as ammonia equivalents and that also undergo flow‐dependent elimination.
Long‐term Performance of Albumin Secretion of Hepatocytes Cultured in a Packed‐bed Reactor Utilizing Porous Resin
Authors: Miyoshi Hirotoshi , Yanagi Kennichi , Fukuda Hideki , Ohshima Norio
Published: November 2008

Abstract: A packed‐bed reactor utilizing the porous polymer, polyvinyl formal (PVF) resin, as a supporting material was applied for the long‐term culture of rat hepatocytes. Perfusion cultures using this reactor, as well as monolayer cultures, were performed for up to 1 week under 3 different media conditions. When serum‐free or epidermal growth factor‐containing medium was used, albumin secretion rates showed constant decreases in both the perfusion and the monolayer cultures, and approximately 10% of the activity exhibited on Day 1 was preserved at the end of the cultures. In contrast, the hepatocytes supplemented with serum‐containing medium exhibited stable ability of albumin secretion throughout the culture period under the perfusion culture condition using PVF resin. From the microscopic observation, the immobilized hepatocytes in this medium revealed round shapes, and a cluster of cell aggregates was scarcely seen.
BCX‐34: A Novel T‐Cell Selective Immunosuppressant: Purine Nucleoside Phosphorylase (PNP) Inhibitor
Authors: Wada Yoshimasa , Yagihashi Atsuhito , Terasawa Katsuhiko , Miyao Noriomi , Hirata Koichi , Cicciarelli James , Iwaki Yuichi
Published: November 2008

Abstract:We evaluated the efficacy of a new purine nucleoside phosphorylase inhibitor, BCX‐34, as an immunosuppressive agent. BCX‐34 showed a complete inhibitory effect on the proliferation of T‐cells in an in vitro system, whereas no influence was observed in B‐cell lines. In addition, it was revealed that this inhibitory effect was not due to the suppression of interleukin‐2 production. Therefore, BCX‐34 might be a potentially useful drug that can be used in combination, not competition, with cyclosporine A and FK506.
Immunomodulation in Transplantation with Photopheresis
Authors: Barr Mark L.
Published: November 2008

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti‐vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula‐tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non‐toxic immunomodulating technology in the field of transplantation.
In Vitro Function and Durability Assessment of a Novel Polyurethane Heart Valve Prosthesis
Authors: Mackay T.G. , Bernacca G.M. , Fisher A.C. , Hindle C.S. , Wheatley D.J.
Published: November 2008

Abstract While flexible‐leaflet, central‐flow prosthetic heart valves promise relief from anticoagulation therapy, they continue to be restricted by inadequate durability. In consequence, a novel trileaflet valve, made entirely from polyurethane, has been developed. A batch of 6 consecutively manufactured polyurethane valves was subjected to hydrodynamic function and accelerated fatigue testing. Computerized data acquisition and control systems have been introduced to improve valve testing methodologies. In terms of hydrodynamic function, the polyurethane valve demonstrates transvalvular pressure gradients similar to those for a bioprosthetic valve (Carpentier‐Edwards) and levels of retrograde flow significantly less than those for either the bioprosthetic valve or a bileaflet mechanical valve (St Jude Medical). The equivalent of 10 years of cycling without failure has been exceeded by all 6 polyurethane valves in accelerated fatigue tests with 2 valves remaining intact after 674 million cycles (equivalent to approximately 17 years) in continuing tests. Highspeed photography revealed considerable differences in leaflet motion between valves cycled at accelerated and physiological rates.
Hemolytic Characteristics of a Pivot Bearing Supported Gyro Centrifugal Pump (C1E3) Simulating Various Clinical Applications
Authors: Takami Yoshiyuki , Makinouchi Kenzo , Nakazawa Tadashi , Benkowski Robert , Glueck Julie , Ohara Yasuhisa , Nosé Yukihiko
Published: November 2008

Abstract Centrifugal blood pumps are playing a key role in circulatory mechanical assist systems including cardiopulmonary bypass (CPB), right and left ventricular assist devices (RVAD and LVAD), percutaneous cardiopulmonary support (PCPS), and extracorporeal membrane oxygenation (ECMO). Each of these circulatory assist systems requires specific flow and pressure conditions. In vitro hemolysis tests were performed using five compact mock loops with flow and pressure set equivalent to clinical conditions. These studies determined the hemolytic characteristics and clinical applicability of the pivot bearing‐supported Gyro centrifugal pump with an eccentric port (C1E3) compared with the Bio‐Medicus pump (BP‐80). Normalized index of hemolysis (NIH) values of the C1E3 were less than those of the BP‐80 under all conditions; in particular, they were significantly less in the CPB, LVAD, and RVAD conditions. In addition, linear correlation was observed between NIH values, rotational pump speed (RPM), total pressure head (ΔP), and flow rate (Q) with both the C1E3 and BP‐80: NIH =a(RPMI Q) + b, NIH =c(ΔP/Q) + d. However, the slopes (a and c) of these equations were smaller with the C1E3 than those with the BP‐80, which suggests that the C1E3 has decreased hemolytic characteristics when increasing the RPM and ΔP. In other words, the increase of RPM and ΔP results in less shear stress with the C1E3 than with the BP‐80. One cause of these decreased hemolytic characteristics of the C1E3 is thought to be less pump power loss against an increase of RPM and ΔP than with the BP‐80. Furthermore, the average exposure time is shorter with the C1E3 than with the BP‐80 because the priming volume of the C1E3 (30 ml) is smaller than that of the BP‐80 (80 ml). From the point of both shear stress and exposure time, the CIE3 has less hemolytic features than the BP‐80.
Therapeutic and Physiological Artificial Heart: Future Prospects
Authors: Nosé Yukihiko , Ohtsubo Satoshi , Tayama Eiki
Published: November 2008

Abstract: Current left ventricular assist devices (LVADs) have demonstrated admirable results. However, approximately one‐fourth of the patients who require LVADs suffer from right heart failure and require additional right ventricular (RV) assist devices (RVADs). The RV failure impairs the splanchnic circulation, subsequently developing into multiorgan failure (MOF). An aggressive application of a biventricular assist device (BVAD) is the best way to avoid and treat MOF because the BVAD reduces splanchnic congestion. Also, because the BVAD allows retention of the natural heart, recovery of the heart function can be expected after long‐term assist. This benefit cannot be expected from conventional total artificial hearts. Although there are no implantable clinical BVAD systems in existence today, present advanced technologies in rotary blood pumps can enable these systems to be totally implantable. So, we should focus on developing a totally implantable BVAD system. The implantable BVAD will be a therapeutic and physiological total artificial heart, and it will be a common home health care device in the near future.
Development of the NimbudPittsburgh Axial Flow Left Ventricular Assist System
Authors: Butler Kenneth , Thomas Douglas , Antaki James , Borovetz Harvey , Griffith Bartley , Kameneva Marina , Kormos Robert , Litwak Philip
Published: November 2008

Abstract: Nimbus, Inc. and the University of Pittsburgh's School of Medicine have been collaborators developing rotary blood pump technology since 1992. Currently, a major focus is on an implantable left ventricular assist system (LVAS) that utilizes an electric powered axial flow blood pump. In addition to the blood pump, a major development item is the electronic controller and the control algorithm for modulating the pump speed in response to varying physiologic demands. Methods being used in developing the axial flow LVAS include the use of computational fluid dynamic modeling of the interior flow field of the pump, flow visualization of the flow field using laser based imaging, and computer simulation of blood pump‐physiological interactions as well as an extensive in vivo test program. Results to date include successful in vivo tests of blood pumps with nonlubricated bearings and demonstrations of auto speed control using electrical current as the observable parameter.
Cora Rotary Pump for Implantable Left Ventricular Assist Device: Biomaterial Aspects
Authors: Montiès J.R. , Dion I. , Havlik P. , Rouais F. , Trinkl J. , Baquey C.
Published: November 2008

Abstract: Our group is developing a left ventricular assist device based on the principle of the Maillard‐Wankel rotative compressor: it is a rotary, not centrifugal, pump that produces a pulsatile flow. Stringent requirements have been defined for construction materials. They must be light, yet sufficiently hard and rigid, and able to be machined with high precision. The friction coefficient must be low and the wear resistance high. The materials must be chemically inert and not deformable. Also, the materials must be biocompatible, and the blood contacting surface must be hemocompatible. We assessed the materials in terms of physiochemistry, mechanics, and tribology to select the best for hemocompatibility (determined by studies of protein adsorption: platelet, leukocyte, and red cell retention: and hemolysis, among other measurements) and biocompatibility (determined by measurement of complement activation and toxicity, among other criteria). Of the materials tested, for short‐ and middle‐term assistance, we chose titanium alloy (Ti6AI4V) and alumina ceramic (Al2O3) and for long‐term and permanent use, composite materials (TiN coating on graphite). We saw that the polishing process of the substrate must be improved. For the future, the best coating material would be diamond‐like carbon (DLC) or crystalline diamond coating.
Clinical Study of Totally Roller Pumpless Cardiopulmonary Bypass System
Authors: Murakami Fumihiko , Usui Akihiko , Hiroura Manabu , Kawamura Mitsuo , Koyama Tomio , Murase Mitsuya
Published: November 2008

Abstract: We have developed a low negative pressure vacuum suction system in which cardiotomy suction is performed by the negative pressure of the venous reservoir controlled by a vacuum controller. We have employed this vacuum suction system with a centrifugal pump as a totally roller pumpless cardiopulmonary bypass (CPB) system. In this study, the clinical availability and hemocompatibility of our totally roller pumpless CPB system were evaluated by a randomized prospective study. Thirty patients undergoing aortocoronary bypass grafting were assigned to the study. Data from seventeen patients treated with a totally roller pumpless CPB system were compared with data from 13 treated with a conventional roller pump CPB system. Totally roller pumpless CPB reduces hemolysis, showing lower plasma free hemoglobin levels (81.8 ± 25.0 versus 42.0 ± 16.3 at 30 min after CPB initiation, p < 0.05). higher plasma haptoglobin levels (37.8 ± 36.6 versus 77.2 ± 31.3 at 120 min after CPB, p < 0.05), and lower blood lactate dehydrogenase (LDH) levels (1391 ± 497 versus 972 ± 187, p < 0.01) than those of CPB with a roller pump suction with no significant difference between platelet counts. Arterial blood oxygen tension after using a totally roller pumpless CPB system was slightly better than that with a roller pump (396 ± 48 versus 437 ± 43, p = 0.069): however, there was no significant difference in intubation times between groups. A totally roller pumpless CPB system provides sufficient biocompatibility for the blood to reduce hemolysis significantly and simplifies and rniniaturizes the entire CPB system to achieve good visuality and handling for control as well.
Biocompatibility of Heparin‐Coated Circuits in Pediatric Cardiopulmonary Bypass
Authors: Kagisaki Koji , Masai Takafumi , Kadoba Keisi , Sawa Yoshiki , Nomura Fumikazu , Fukushima Norihide , Ichikawa Hajime , Ohata Toshihiro , Suzuki Ken , Taketani Satoshi , Matsuda Hikaru
Published: November 2008

Abstract: In this study, we evaluated the biocompatibility of heparin‐coated circuits in pediatric cardiopulmonary bypass (CPB). Eight patients were divided into 2 groups: the control group (Group C) and heparin‐coated group (Group H). In Group H, CPB circuits, including the arterial pump, oxygenator, and cannulas were heparin‐coated. Before, during, and after CPB, blood samples were obtained to assess the platelet counts (Plat), α2‐plasmin plas‐minogen inhibitor complex (PIC), thrombin‐antithrombin III complex (TAT), C3 activation products (C3a), inter‐leukin (IL)‐6, IL‐8, and polymorphonuclear neutrophil leukocyte (PMN) elastase. There was no significant difference in Plat, PIC, or TAT between groups. Group H showed significantly low levels of C3a (during and after CPB), PMN elastase (during CPB), and IL‐6 (after CPB). These data demonstrated that in pediatric CPB, heparin‐coated CPB circuits reduced the activation of complements and the production of PMN elastase and IL‐6, suggesting the superior biocompatibility of the heparin‐coated circuits.
A New Blood Pump for Cardiopulmonary Bypass: The HiFlow Centrifugal Pump
Authors: Göbel Christof , Eilers Rolf , Reul Helmut , Schwindke Peter , Jörger Manfred , Rau Günter
Published: November 2008

Abstract: Centrifugal blood pumps are considered to be generally superior to the traditionally used roller pumps in cardiopulmonary bypass. In our institute a new lightweight centrifugal sealless blood pump with a unique spherical thrust bearing and with a magnetic coupling was developed, the HiFlow. The small design makes the pump suitable for applications in complex devices or close to a patient. Hemolysis tests were carried out in which the BioMedicus pump BP‐80 and a roller pump were used as reference. The centrifugal pump HiFlow showed the least blood trauma within the group of investigated pumps. In summary, the HiFlow pump concept with its low priming volume and limited contact surfaces shows great potential for clinical applications in cardiopulmonary bypass. Also, the possibility of using the pump as a short‐term assist device with an option of a pulsatile driving mode was demonstrated.
Vigabatrin extracellular pharmacokinetics and concurrent γ‐aminobutyric acid neurotransmitter effects in rat frontal cortex and hippocampus using microdialysis
Authors: Tong Xin , Ratnaraj Neville , Patsalos Philip N.
Published: November 2008

Purpose: To investigate the pharmacokinetic interrelationship of vigabatrin in blood and the brain (frontal cortex vs. hippocampus) and to ascertain the relationship between brain extracellular vigabatrin concentrations and concurrent γ‐aminobutyric acid (GABA) concentrations.

Methods: Sprague‐Dawley rats were implanted with a jugular vein catheter for blood sampling, and microdialysis probes in the frontal cortex and hippocampus for extracellular fluid (ECF) sampling. Vigabatrin was administered intraperitoneally at two different doses (500 and 1,000 mg/kg), and blood and ECF were collected at timed intervals up to 8 h. Rats were freely moving and behaving. Vigabatrin (sera and ECF) and GABA (ECF) concentrations were measured with use of high performance liquid chromatography (HPLC).

Results: Vigabatrin concentrations in blood rose linearly and dose‐dependently, and vigabatrin rapidly appeared in the brain as evidenced by the detection of vigabatrin in the ECF of both the frontal cortex and hippocampus at time of first sampling (15 min). However, frontal cortex concentrations were twofold greater than those of the hippocampus. Furthermore, GABA concentrations increased five‐fold in the frontal cortex but were unaffected in the hippocampus. In addition, GABA concentrations began to increase approximately 3 h after vigabatrin administration at a time when vigabatrin concentrations were in exponential decline.

Conclusions: Vigabatrin distribution in the brain is region specific, with frontal cortex concentrations substantially greater than those seen in the hippocampus. Elevation of GABA concentrations did not reflect the concentration profile of vigabatrin but reflected its regional distribution.
Six years' experience performing RHD genotyping to confirm D− red blood cell units in Germany for preventing anti‐D immunizations
Authors: Flegel Willy A. , Von Zabern Inge , Wagner Franz F.
Published: November 2008

BACKGROUND: Red blood cell (RBC) units of D+ donors are falsely labeled D− if regular serologic typing fails to detect low D antigen expression or chimerism. The limitations of serology can be overcome by molecular typing.

STUDY DESIGN AND METHODS: In January 2002, we introduced a polymerase chain reaction (PCR)‐based assay for RHD as a routine test for first‐time donors who typed D− by serologic methods including the indirect antiglobulin test. Samples were tested in pools of 20 for the RHD‐specific polymorphism in Intron 4. RHD alleles were identified by PCR and nucleotide sequencing.

RESULTS: Within 6 years, 46,133 serologically D− first‐time donors were screened for the RHD gene. The prevalence of RHD gene carriers detected by this method was 0.21 percent. Twenty‐three RHD alleles were found of which 15 were new. Approximately one‐half of the RHD gene carriers harbored alleles expressing a DEL phenotype resulting in a prevalence of 0.1 percent.

CONCLUSION: The integration of RHD genotyping into the routine screening program was practical. We report 6 years' experience of this donor testing policy, which is not performed in most transfusion services worldwide. RBC units of donors with DEL phenotype have been reported to anti‐D immunize D− recipients. We transferred those donors to the D+ donor pool with the rationale of preventing anti‐D immunizations, especially dreaded in pregnancies. For each population, it will be necessary to adapt the RHD genotyping strategy to the spectrum of prevalent alleles.
Anti‐“Mia” immunization is associated with HLA‐DRB1*0901
Authors: Chu Chen‐Chung , Ho Hsin‐Tsung , Lee Hui‐Lin , Chan Yung‐Shiu , Chang Fong‐Juan , Wang Chang‐Ling , Lin Marie
Published: November 2008

BACKGROUND: Anti‐“Mia” is one of the most important irregular red blood cell antibodies found in Taiwan. The aim of this study was to investigate whether specific HLA‐DRB1 alleles are associated with anti‐“Mia” production.

STUDY DESIGN AND METHODS: A case‐control retrospective study was performed on 68 patients showing presence of anti‐“Mia” and 219 unrelated control subjects from the Mackay Memorial Hospital. HLA‐DRB1 genotyping was carried out using sequence‐based typing method. Fisher's exact test using 2 × 2 contingency tables was used to analyze significance of the association between DRB1 polymorphisms and presence of anti‐“Mia” in patients.

RESULTS: HLA‐DRB1*0901 allele frequency in the anti‐“Mia” group (30%) was significantly higher than in the control group (16%) with an odds ratio of 2.27 (95% confidence interval, 1.44‐3.55; p = 0.0005; pc = 0.016).

CONCLUSION: HLA‐DRB1*0901 is significantly more prevalent in the anti‐“Mia” patients group than in the control group. It is suggested that cells from DR9 individuals might present processed “Mia” antigen‐allospecific peptides more effectively than cells from individuals carrying other DR phenotypes. Finally, it was predicted that two epitopes, derived from the MiIII glycophorin amino acid sequence, were likely to bind preferentially with the DR9 molecule. Further work will be necessary to determine if these epitopes are responsible for anti‐“Mia” alloimmunization.
The Initial Changes of Fat Deposits During the Decomposition of Human and Pig Remains
Authors: Notter Stephanie J. , Stuart Barbara H. , Rowe Rebecca , Langlois Neil
Published: November 2008

Abstract:  The early stages of adipocere formation in both pig and human adipose tissue in aqueous environments have been investigated. The aims were to determine the short‐term changes occurring to fat deposits during decomposition and to ascertain the suitability of pigs as models for human decomposition. Subcutaneous adipose tissue from both species after immersion in distilled water for up to six months was compared using Fourier transform infrared spectroscopy, gas chromatography‐mass spectrometry and inductively coupled plasma‐mass spectrometry. Changes associated with decomposition were observed, but no adipocere was formed during the initial month of decomposition for either tissue type. Early‐stage adipocere formation in pig samples during later months was detected. The variable time courses for adipose tissue decomposition were attributed to differences in the distribution of total fatty acids between species. Variations in the amount of sodium, potassium, calcium, and magnesium were also detected between species. The study shows that differences in total fatty acid composition between species need to be considered when interpreting results from experimental decomposition studies using pigs as human body analogs.
Developing a Spatial‐Temporal Method for the Geographic Investigation of Shoeprint Evidence
Authors: Lin Ge , Elmes Gregory , Walnoha Mike , Chen Xiannian
Published: November 2008

Abstract:  This article examines the potential of a spatial‐temporal method for analysis of forensic shoeprint data. The large volume of shoeprint evidence recovered at crime scenes results in varied success in matching a print to a known shoe type and subsequently linking sets of matched prints to suspected offenders. Unlike DNA and fingerprint data, a major challenge is to reduce the uncertainty in linking sets of matched shoeprints to a suspected serial offender. Shoeprint data for 2004 were imported from the Greater London Metropolitan Area Bigfoot database into a geographic information system, and a spatial‐temporal algorithm developed for this project. The results show that by using distance and time constraints interactively, the number of candidate shoeprints that can implicate one or few suspects can be substantially reduced. It concludes that the use of space‐time and other ancillary information within a geographic information system can be quite helpful for forensic investigation.
Stature Estimation Formulae for Nigerians
Authors: Didia Blessing C. , Nduka Ethelbert C. , Adele Okechukwu
Published: November 2008

Abstract: In stature estimation, long limbs and the stature formula of Trotter and Gleser easily come to mind. In the recent past, a lot of workers have established formulae specific to their populations using whole length of limbs, fragmented bones, circumference of long bones, and even length of the vertebrae. We have in this work used tibia length, height of subjects, and the regression models to establish formulae specific to Nigerians. We measured height and tibia length of 200 (96 male and 104 female) adult Nigerians. The tibia length was measured from upper limit of the medial condoyle to the tip of medial malleolus using a measuring tape calibrated in meters while the height of individuals were also measured using meter scales. All measurements were made by one person, to avoid interobserver error, and repeatedly until a constant value is obtained. We obtained general formulae for males and females which compares favorably with that of Duyar and Pelin, and can be relied upon.
Movement of grape mealybug, Pseudococcus maritimus, on and between host plants
Authors: Grasswitz Tessa R. , James David G.
Published: November 2008

The importance of the grape mealybug, Pseudococcus maritimus (Ehrhorn) (Homoptera: Pseudococcidae), as a pest of wine grapes, Vitis vinifera L. (Vitaceae), has increased as a result of recent reports that it is capable of transmitting at least one of the viruses associated with grapevine leafroll disease. However, its natural rate of movement between host plants – and hence its role in the epidemiology of this disease – is poorly understood. In order to better assess the risk of field spread of leafroll disease by this insect, several experiments were conducted to determine the extent to which P. maritimus can move between grape plants, both by walking and by airborne dispersal. In experiments with first instars, both field and shade‐house studies indicated that the mealybugs do not walk far and only very rarely reach adjacent plants by this means. Field trapping experiments showed that grape mealybugs can be dispersed by wind, but that there is a marked decline in numbers with increasing distance from the source plant. The implications of these observations for the field spread and management of grapevine leafroll disease are discussed.