bluuebunny/crossref_metadata_2025 huggingface dataset:
Behavior of Endothelial Cells Cultured on Silastic and Dacron Velour Under Flow Conditions In Vitro: Implications for Prelining Vascular Grafts with Cells
Authors: Eskin Suzanne G. , Navarro Lydia T. , O'Bannon William , DeBakey Michael E.
Published: November 2008

Summary: Tissue‐cultured bovine aortic endothelial cells were subjected to flow in an in vitro circulatory loop designed to simulate the flow and pressure conditions in the aorta. The cells were cultured under stationary conditions on tubes of fibronectin‐coated Silasticr̀ or of Dacronrr̀ velour. The tubes were then added to the flow loop, which circulated complete tissue culture medium in a pulsatile mode. Light microscopy and cell counts showed that the cells not only remained adherent for up to 2 weeks under flow conditions, but also underwent hypertrophy and proliferation in response to the flow regimen.
Experimental Results for Chronic Left Ventricular Assist and Total Artificial Heart Development
Authors: Nosé Yukihiko , Jacobs Gordon , Kiraly Raymond J. , Golding Leonard , Harasaki Hiroaki , Takatani Setsuo , Murabayashi Shun , Sukalac Ronald W. , Kambic Helen , Snow Jeffrey
Published: November 2008

Summary: After more than 20 years of research on the artificial heart, it is now accepted that the pneumatically actuated total artificial heart can maintain near‐normal physiology in experimental animals for several months. Such systems are clinically acceptable for short‐term application (a few months) in patients waiting for a suitable heart transplant. However, realistically, a cardiac prosthesis that has the capability of being totally implantable for over 2 years must be available. Based on this premise, our group initiated the development of a mechanically actuated total artificial heart, capable of coupling with either a thermal or electrical actuation system. Since 1977, under the National Institutes of Health chronic left ventricular assist program, we have used two different pusher‐plate pumps and electrical systems. Taking advantage of technology generated in these programs, we began developing a prosthesis to replace the total cardiac function. This paper is a summary of both the chronic left ventricular assist and total artificial heart development progress in this laboratory.
Development and Evaluation of a Long‐Term, Implantable, Electrically Actuated Left Ventricular Assist System: THI/Gould LVAS
Authors: Norman John C. , McGee Michael G. , Fuqua John M. , Igo Stephen R. , Turner Stephen A. , Sterling Rosalyn , Urrutia Carlos O. , Frazier O. H. , Clay Warren C. , Chambers Jack A.
Published: November 2008

Summary: A long‐term, impĺantable, electrically actuated left ventricular assist system (THI/Gould LVAS) is being developed and characterized in vitro and in vivo for utilization in patients with end‐stage heart disease. This system consists of five major components: a long‐term, implantable blood pump (THI E‐type ALVAD); an electrical‐mechanical energy converter (Gould Model V); a control unit with batteries; a volume compensation system; and an external power supply and monitoring unit. Two of these components (blood pump and electrical‐mechanical energy converter) have been integrated, and are undergoing chronic in vivo evaluations in calves. Thus far, 44 pneumatically and electrically actuated THI/Gould LVAS evaluations have been performed. This experience has resulted in >6.5 years of actuation in vivo, with durations exceeding 1 year. System in vivo performance in terms of durability, mechanical reliability, hemodynamic effectiveness, and biocompatibility has been satisfactory. Demonstration of long‐term (2‐year) effectiveness in supporting the circulation is the ultimate goal.
Implanted Artificial Heart with Radioisotope Power Source
Authors: Shumakov Valeriy I. , Griaznov Georgiy M. , Zhemchuzhnikov Genri N. , Kiselev Iuriy M. , Osipov Anatoliy P.
Published: November 2008

Summary: An atomic artificial heart for orthotopic implantation was developed with the following characteristics: volume, 1.2 L; weight, 1.5 kg; radioisotope power, 45 W; operating life, up to 5 years; hemodynamics, similar to natural hemodynamics. The artificial heart includes a thermal drive with systems for regulating power, feeding steam into the cylinders, return of the condensate to the steam generator, and delivery of power to the ventricles and heat container. The artificial heart is placed in an artificial pericardium partially filled with physiologic solution. It uses a steam engine with two operating cylinders that separately drive the left and right ventricles. There is no electronic control system in the proposed design. The operation of the heat engine is controlled, with preservation of autoregulation by the vascular system of the body. The separate drives for the ventricles is of primary importance as it provides for operation of the artificial heart through control of cardiac activity by venous return. Experimental testing on a hydromechanical bench demonstrated effective autoregulation.
Assisted Circulation in Cardiac and Respiratory Insufficiency
Authors: Shumakov Valeriy I. , Tolpekin Vladimir E. , Pisarevskii Averiy A.
Published: November 2008

Summary: Intra‐aortic counterpulsation with a balloon pump (IABP) was used in 63 patients with cardiogenic shock, heart failure after surgery with artificial circulation, internal lacerations of the myocardium, or unstable angina. It was found that the IABP was most efficient in conditions related to myocardial ischemia. Use of arteriovenous perfusion (in 11 patients) or artificial ventricles is indicated in severe perturbations of the pumping function of the heart. As experience has shown, cardiologic and heart surgery patients usually have multiorgan insufficiency. For this reason, it is necessary to use other artificial organs in complex treatment: artificial lungs, kidneys, livers, etc.
Prospects for Using Implanted Systems of Assisted Circulation and Artificial Heart with a Radioisotope Power Source (Biomedical, Thermal, and Radiation Aspects)
Authors: Kiselev Iuriy M. , Dubrovskii Georgiy P. , Mosidze Tengiz G. , Bazhanov Alexander Iu.
Published: November 2008

Summary: The capacity of dogs to diffuse heat (up to 50 W) from an artificial heart and to tolerate prolonged intracorporeal ionizing radiation from a radioisotope power source (238Pu) was investigated, using electrical models of vascular blood heat exchangers that permit reproduction of elimination and heat transmission in autonomous systems. It was shown that up to 50 W can be discharged at temperatures of the wall‐blood interface that do not exceed 43d̀C. Clotting indexes, concentration of total protein, hemolysis, and serum enzyme activity during 1‐1.5 months of heating remained within physiologically normal limits. A specific power load of up to 1.5 W/kg at ambient temperatures of 18–20d̀C revealed no evidence of changes in heat production. By measuring the distribution of power of the dose absorbed around a 45‐W plutonium source it was possible to estimate dose loads on critical organs and to assess overall risk of death from malignant tumors induced by radiation over a 10‐year period: 6–12% for males and 8–14% for females. It is not very probable that use of the artificial heart with a radioisotope power source will be limited by thermal and radiational effects.
Biomedical Aspects of Cardiac Massage in Experiments and Clinical Practice
Authors: Egorov Titsian L. , Zimin Nikolai K. , Kormer Arkadiy Ia. , Lektorskii Boris I.
Published: November 2008

Summary: Despite current successes in modern cardiology and heart surgery, the problem of restoring and maintaining cardiac function in cases of sudden arrest or ventricular insufficiency is still urgent. Different methods of mechanically assisting the heart and replacing its pumping function exist, and direct mechanical cardiac massage (DMCM) is one of the more important. Experimental results with dogs and calves on 2‐to 4‐h DMCM, cardiac massage lasting for up to 48 h, subsequent restoration of cardiac activity, and cardiac massage during experimentally induced myocardial infarction permitted clinical application in patients with myocardial infarction complicated by ventricular fibrillation. DMCM also permits extension of the possibilities of obtaining and transplanting donor organs. It is one of the variants for solving the problem of total and partial replacement of the pump function of the heart, and now makes it possible to solve some important problems in transplantation and cardiac resuscitation.
Double‐Blind Evaluation of Plasmapheresis in Schizophrenic Patients: A Pilot Study
Authors: Schulz S. Charles , van Kammen Daniel P. , Waters Robert , Klein Harvey G. , Balow James E. , Bunney William E.
Published: November 2008

Abstract: Interest in the effects and possible mechanisms of hemodialysis on schizophrenic patients has led to a double‐blind evaluation of the effects of plasmapheresis on symptoms of schizophrenia. Also, plasmapheresis was felt to be an invaluable tool for investigating the autoimmune theory of schizophrenia. Patients (n = 10) in the study fulfilled Research Diagnostic Criteria for schizophrenia and were randomly assigned to either sham or active plasmapheresis. They were blindly assessed by staff psychiatrists and nurses. Evaluation of the behavioral ratings revealed no significant decrease in psychosis for either the active or sham group. Also, no individual responding patient was identified. This finding complements our group's early negative results of a hemodialysis experiment and casts doubt on a simple autoimmune hypothesis of schizophrenia.
Influence of Hemodialysis on Monoamine Oxidase Kinetics in Platelets from Chronic Schizophrenic Patients
Authors: Wahlund L. O. , Smedby Y. , Sääf J. , Schulman A. , Ross A. B. , Wetterberg L.
Published: November 2008

Abstract: Platelet monoamine oxidase (MAO) activity in seven chronic schizophrenic patients undergoing hemodialysis treatment was studied. The treatment was performed in a double‐blind crossover design. A significant increase in MAO activity was observed after 5 h of active dialysis, whereas inactive dialysis did not significantly alter the enzyme activity. The increase in MAO activity could be explained by the observed significant decrease in apparent Km values for the amine (phenethylamine) studied. During a treatment period of 8 weeks, the MAO activity was not significantly altered with either active or sham dialysis. No relation between clinical ratings and platelet MAO activity was observed. Plasma from the seven patients was collected before and after 5 h of active or inactive dialysis and incubated with rat brain mitochondrial MAO (RBM‐MAO). No difference was noted in the RBM‐MAO‐activity‐regulating properties of the plasma sampled during either sham or active dialysis.
A Noninvasive Determination of Fistula Blood Flow in Dialysis Patients
Authors: Bouthier J. D. , Levenson J. A. , Simon A. C. , Bariety J. M. , Bourquelot P. E. , Safar M. E.
Published: November 2008

Abstract: Arteriovenous fistula (AVF) blood flow was evaluated in 32 dialysis patients using a pulsed Doppler velocimeter with two dominant features: a range‐gated time system and a double transducer probe. With the proposed apparatus, the observation angle between the ultrasound beam and the vessel axis was known. In radial AVF, blood flow was 728 ± 53 ml/min and was negatively correlated with the age of the AVF (r=‐0.62; p<0.01). In brachial AVF, blood flow was 778 ± 152 ml/min. In bovine heterograft AVF, blood flow was 1,225 ± 125 ml/min. In the overall population, a negative relationship was observed between the diameter of the fistula and the blood flow velocity (r=‐0.57; p<0.01). The study describes an accurate noninvasive method for the determination of fistula blood flow in dialysis patients, which may be helpful in the follow‐up of the regional hemodynamics of this vascular access.
Plasma Exchange for Treatment of Intractable Psoriasis
Authors: Maeda Kenji , Shinzato Torn , Naotsuka Masaaki , Usuda Masatsune , Sezaki Ryozo , Niwa Toshimitsu , Kawaguchi Shunsuke , Saito Akira , Yamanaka Naoki , Ohta Kazuhiro
Published: November 2008

Abstract: Hemofiltration and plasma exchange, using a plasma separator with membranes, were used in 14 psoriatic patients. The efficacies of the treatments were compared. Among the patients, 13 were treated with hemofiltration and/or direct hemoperfusion, 5 experienced complete remission, 5 improved, and 3 remained unaffected. In these 3 cases, plasma exchange was performed. The first patient, who suffered from psoriasis pustulosa with arthropathica, achieved complete remission with only two treatments of 2‐L plasma exchange. Joint pain was also eliminated. Both skin lesions and joint pain were markedly improved in the second patient, who suffered from psoriasis vulgaris with arthropathica. The third patient showed marked improvement with only two plasma exchanges, and is under continuing observation.
Production of Thiobarbituric Acid‐Reactive Material During Experimental Cardiopulmonary Bypass in Cows
Authors: Fleming J. S.
Published: November 2008

Abstract: Increased levels of thiobarbituric acid (TBA)‐reactive material were found in the plasma of cows during experimental cardiopulmonary bypass. The levels of TBA‐reactive substance decreased during the postoperative period to levels statistically lower (50%; p < 0.001) than the preoperative values. The increased TBA reactivity of the plasma is indicative of lipid peroxidation during the perfusion period, owing either to exposure of the blood to increased Po2 or to oxygen radical formation. Activation of phagocytic cells by membrane contact and complement activation can induce phagocytic killing processes with the release of oxygen radicals. Although the absolute neutrophil count increased during the perfusion period, convincing correlation with the TBA reactivity was not found, and the origin of the TBA‐reactive material remains speculative.
Autoclave Sterilization of Polypropylene Plasma Separator
Authors: Sato Hiroshi , Watanabe Koichi , Minezawa Teruo , Hori Masatake
Published: November 2008

Abstract: A water‐prefilled, autoclave‐sterilized plasma separator (PS) was developed to improve handling procedures prior to use. Two types of polypropylene membranes differing in pore size were used to evaluate the effect of the autoclaving on various parameters. Their performance was evaluated by an in vitro filtration study using bovine blood. The membrane with the larger pore size showed a significantly (p < 0.05) higher filtration rate, although the sieving coefficients for proteins were similar to those for the membrane with the smaller pore size. The water‐prefilled PS with autoclave sterilization showed filtration and sieving properties similar to those of the nonautoclaved PS. Its performance suggests that it might be acceptable for clinical study.
Red Blood Cell Deformability and Secondary Hyperparathyroidism in Uremic Patients on Maintenance Hemodialysis
Authors: Docci D. , Turci F. , Salvi P. , Pretolani E.
Published: November 2008

Abstract: The possible relationship between red blood cell (RBC) deformability and secondary hyperparathyroidism (HPT) in 23 patients on maintenance hemodialysis was examined. Secondary HPT was evaluated by means of serum biochemistry (parathyroid hormone, calcium, phosphorus, and alkaline phosphatase) and radiographic examinations. This study showed that RBC deformability is markedly reduced in hemodialyzed patients when compared with normal controls. No significant correlation between RBC deformability and the hemato‐chemical changes associated with secondary HPT was found. No difference in RBC deformability was observed as far as the activity (alkaline phosphatase) and the severity (radiographic findings) of secondary HPT are concerned. Effective treatment of secondary HPT by either pharmacological means (1α, 25‐dihydroxycholecalciferol therapy) or surgical removal was not associated with consequent improvement in RBC deformability. It is concluded that secondary HPT is probably not a major factor influencing RBC deformability in uremic patients on maintenance hemodialysis.
Leukopenia, Hypoxemia, and Complement Activation During a Single Hemoperfusion
Authors: Taccone‐Gallucci Massimo , Pericone Roberto , de Carolis Caterina , Fontana Luigi , Mazzarella Valentina , Morosetti Massimo , Casciani Carlo Umberto
Published: November 2008

Abstract: White blood cell count, acid‐base balance, Po2, and complement function in five uremic patients undergoing a single hemoperfusion employing activated charcoal coated with methacrylate were studied. After 20 min on hemoperfusion, a marked leukopenia [ranging from 6,080±526 to 3,740±1,124 (p<0.02)] and hypoxemia [ranging from 106±13.8 to 80.2±11.9 mm Hg (p<0.02)] were observed. At the same time, total hemolytic complement decreased from 135±15.7 to 123±14.7 U/ml (p< 0.001) and alternative pathway activity from 38.1±5.1 to 33.1±6.7 U/ml (p <0.005). C3 and B cleavage fragments were detected in the samples tested, thus demonstrating the activation of the complement alternative pathway. After 60 min, the different parameters tended to increase but did not reach the baseline levels. A direct correlation between the degree of leukopenia and the reduction of Po2 throughout the hemoperfusion period was found. pH, Pco2, and HCO3 did not change throughout the hemoperfusion period. The results demonstrate that complement activation, leukopenia, and hypoxemia occur during hemoperfusion.
Enzymatic Detoxification Using Lipophilic Hollow‐Fiber Membranes: I. Glucuronidation Reactions
Authors: Brunner G. , Tegtmeier F.
Published: November 2008

Abstract: A lipophilic hollow‐fiber membrane preparation was used in the enzymatic detoxification of lipophilic toxins. Native enzymes were circulated on one side of the lipophilic membrane, while the toxin‐containing media (blood, serum, waste fluids, etc.) were circulated inside the hollow fiber. Lipophilic substances that accumulate in and penetrate the lipophilic membrane were converted by the corresponding enzymes. Phase II detoxifying enzymes converted the lipophilic toxins to hydrophylic compounds that made a rediffusion of these molecules back to the blood impossible. Glucuronidation reactions were catalyzed by a crude preparation of solubilized uridine‐5′‐diphosphate‐glucuronyltransferase (EC 2.1.1.9) with a specific activity of 10.0 nmol/min/mg protein in the presence of uridine‐5′‐diphosphoglucuronic acid (acceptor: phenol as reference substrate). Clearance rates of phenol, 1‐naphtol, 2‐naphtol, and p‐cresol were measured, respectively, to be 141, 195, 300, and 251 pmol/ h/mg protein/cm2 hollow fiber. The advantage of this technique lies in the possibility of using highly active, soluble enzyme preparations and a fully utilizable cofactor supply. The lipid membrane ensures the absence of immunological hazards, while mass transfer of the toxin is not impaired.
Development of Polyetherurethane Sheet Embedded with Powdered Charcoal for Use in Hemoperfusion
Authors: Kawanishi Hideki , Nishiki Masayuki , Sugiyama Masafumi , Cho Tuneo , Tsuchiya Taro , Ezaki Haruo
Published: November 2008

Abstract: This article describes the development of a polyetherurethane sheet embedded with powdered charcoal (UPC) for use in a hemoperfusion system. The UPC was 200 μm thick and the release of microparticles could be limited. The powdered charcoal used was selected for optimum pore size distribution and particle size (10–40 μm) to provide a maximum adsorption of bilirubin. The results of an in vitro adsorption test with this material showed an adsorption of bilirubin approximately 14 and 6 times higher than those by bead‐type charcoal and XAD‐7, respectively. Jaundiced dogs were subjected to direct hemoperfusion through a UPC column containing 36 g powdered charcoal. Effective decreases in bilirubin were observed, giving the maximum removal amounts of 78% in conjugated bilirubin and 76% in unconjugated bilirubin.
Ex Vivo Preclinical Evaluation of Membrane Plasma Separators
Authors: Matsubara S. , Wojcicki J. M. , Sueoka A. , Horiuchi T. , Matsugane T. , Starre J. J. , Smith J. W. , Malchesky R S. , Nosé Y.
Published: November 2008

Abstract: Four different types of hollow‐fiber membrane plasma separators, constructed of cellulose acetate, polyvinyl alcohol, polyethylene, and polymethylmethacrylate membranes, were evaluated in ex vivo dog perfusions under conditions simulating their clinical use. An arteriovenous (A‐V) fistula constructed in the dogs for blood access enabled repeated access to be achieved without surgical intervention. All modules produced transient leukopenia and a reduction of platelet counts. The polymethylmethacrylate module showed minimum reductions of white blood cell counts and CH50. The early leukocyte count reduction in membrane plasmapheresis is most likely related to the magnitude of complement activation by the membrane, as is seen with hemodialysis.
Heart Substitution: Transplantation and Total Artificial Heart. The Texas Heart Institute Experience
Authors: Cooley Denton A.
Published: November 2008

Abstract: Two methods of heart substitution have been used at the Texas Heart Institute: cardiac transplantation and the total artificial heart (TAH). Cardiac transplantation is an effective means of saving patients with end‐stage heart disease and, since the introduction of the immunosuppressive agent cyclosporine, survival has increased significantly. In a recent series from July 1982 to May 1984, 25 patients underwent cardiac transplantation at the Texas Heart Institute. Nineteen of these patients are alive, in Functional Class I, and leading normal lives.

A major disadvantage of cardiac transplantation is that it cannot be used on an emergency basis for postcardiotomy patients. In this situation, TAH has been used twice (1969 and 1981) as the first stage to maintain circulation prior to subsequent cardiac transplantation. In both instances, the TAH functioned well until a satisfactory donor was found. This demonstrates the feasibility of the two‐staged concept and encourages further development of cardiac prostheses.
Hypotensive Effect of Plasma Exchange in Immune Complex Nephritis
Authors: Puccini R. , Fommei E. , Meconi P. , Moriconi L. , Palombo C. , Pasquariello A. , Ferri C. , Cioni L. , Ghione S.
Published: November 2008

Abstract: The effect of plasma exchange (PE) on blood pressure (BP) in 20 hypertensive patients (9 with mixed cryoglobulinemia, 7 with systemic lupus erythematosus, and 4 with idiopathic glomerulonephritis) was evaluated retrospectively. In each PE 1.5–2.5 L of plasma was replaced with an equal volume of 4% albumin polysaline solution. The frequency of PE was three times per week for the first 2 weeks and twice per week subsequently. Sixteen patients were on hypotensive treatment at the onset of PE. Their systolic/diastolic BP was 171 ± 4.7/ 102 ± 3.0 mm Hg (x̄± 1 SEM). After 4 weeks, BP decreased to 141 ± 2.8/89 ± 2.3 mm Hg (p < 0.001), although in 10 patients antihypertensive drug therapy had been reduced or discontinued. The most marked decrease of BP occurred after the first week (152 ± 5.3/92 ± 2.9 mm Hg), and this decrement correlated remarkably well with pressure levels before PE despite the great heterogeneity of the individual patients (for diastolic BP, r = 0.87, p < 0.001; for systolic BP, r = 0.60, p < 0.01). A mild decrease of serum creatinine was observed during PE, but its time course was different from that of BP, and did not correlate with this parameter.
Double‐Blind Randomized Trial of the Effect of Ticlopidine in Arteriovenous Fistulas for Hemodialysis
Authors: Fiskerstrand C. E. , Thompson I. W. , Burnet M. E. , Williams P. , Anderton J. L.
Published: November 2008

Abstract: The antiplatelet drug ticlopidine was assessed as an agent for improving the patency of Brescia‐Cimino arteriovenous fistulas as access for hemodialysis. In a double‐blind randomized study over 1 month, two of six fistulas in the ticlopidine group and five of nine in the placebo group failed. A further one placebo and two ticlopidine patients still had functioning fistulas at the time of withdrawal for technical reasons from the trial. Ticlopidine appears, therefore, to enhance the efficacy of Brescia‐Cimino fistulas, at least in the short term.
Erythroid Progenitor Growth in Erythrocytosic Transplanted Patients
Authors: Lamperi Silvano , Carozzi Silvia
Published: November 2008

Abstract: In 55 patients who underwent renal transplantation, erythrocytosis (E) was observed in 6. In all patients, the growth of erythroid progenitors [burst‐forming unit erythroid (BFU‐e)], using mononuclear blood cells, was evaluated in in vitro cultures. The results showed a significant increase of serum erythropoietin (s‐Ep) in erythrocytosis and in nonerythrocytosis patients with a subsequent decrease when hematocrit (Hct) and hemoglobin (Hb) reached high levels, showing a recovery of a feedback control system. Notwithstanding the diminution of s‐Ep, six patients demonstrated further progressive rise of the Hct and Hb to a final state of E. The in vitro BFU‐e cultures from these patients showed a noticeable sensitivity to progressively reduced doses of Ep and also the capacity to develop a few colonies when the medium was Ep‐free. These results were not verified using peripheral blood depleted of monocyte and/or T lymphocyte cells. Therefore, in transplanted patients with erythrocytosis, it is possible that particular cellular interactions stimulate an early hyperproliferation of BFU‐e with a greater Ep sensitivity and at least partly the capacity to grow also in the absence of Ep.
Utilization of Activated Carbon Hemoperfusion to Assist Recovery of Ischemically Damaged Canine Liver Allografts
Authors: Toledo‐Pereyra Luis H.
Published: November 2008

Abstract: The sensitivity of liver allografts to even minimal periods of ischemia currently limits the duration of hepatic preservation prior to liver transplantation. This study evaluates the role of activated carbon hemoperfusion (ACH) for assisting the recovery of canine livers ischemically damaged by a 20‐min occlusion of the portal vein and hepatic artery prior to organ harvesting. Animals in Group I (n = 5) receiving damaged liver allografts without ACH survived a mean (±SD) of 18.0 ± 13.5 h. One ACH treatment given to recipients immediately after liver transplantation in Group II (n = 5) resulted in improved survival to a mean of 3.8 ± 2.16 days (p < 0.05). The best survival was obtained after three ACH treatments in Group III (n = 6) on days 0, 1, and 2 (26.6 ± 27.1 days) (p < 0.05). These results indicate that ACH may be helpful in assisting the recovery of ischemically damaged liver allografts after transplantation.
Theoretical Formulation of Sieving Coefficient Evaluation for Membrane Plasma Separation
Authors: Weryński Andrzej , Malchesky Paul S. , Lewandowski Jan J. , Waniewski Jacek , Wójcicki Jan , Piatkiewicz Wojciech
Published: November 2008

Abstract: Three different sieving coefficient definitions were theoretically investigated. It has been shown that the local sieving coefficient, characterizing membrane property, can be calculated under specified assumptions from input — output measurements. In contrast, the evaluation of the device sieving coefficient, useful in kinetic modeling, is validated in a situation in which calculation of the local sieving coefficient is connected with substantial error. The relationship between different sieving coefficient definitions is also given.
Can Plasma Concentration of Middle Molecules Contribute to Assessment of Adequate Dialysis Treatment?
Authors: Válek Albert , Spustová Věra , Lopot František , Erben Josef , Dzúrik Rastislav
Published: November 2008

Abstract: The aim of this study was to confirm or to reject whether plasma concentrations of individual fractions of middle molecular weight substances can become parameters for an adequate dialysis treatment and whether there exists a relation between that and some symptoms and signs in patients on regular dialysis. No changes in clinical condition, plasma concentration of middle molecules, or metabolic state after 5 years of short‐time dialysis schedule were established. No difference was found in the plasma concentration of middle molecules after 6 months of continuous ambulatory peritoneal dialysis and in patients undergoing hemodialysis treatment. There was also no difference in glomerular filtration rate, blood urea concentration, dialysis index, and duration of regular dialysis treatment in patients with a middle molecular fraction 2 level lower and higher than 5.5 U/L. Elimination of fractions 2–4 and 6 by a 1‐m2 Cuprophan coil dialyzer was similar to the elimination of creatinine. Only patients with acute respiratory infection had a fraction 2 higher than controls. Neither conventional parameters nor plasma concentrations of middle molecules can be indicators of an adequate dialysis. The well‐being of patients and their metabolic state are the only criteria.
Colostomy Control Device
Authors: Numanoglu Ihsan
Published: November 2008

Abstract: Temporary or permanent colostomy produces many difficulties such as continuous fecal flow, odor, skin irritation, rash, edema, and uncleanliness. Efforts to resolve these difficulties have not had much success. The present work describes the development of a new colostomy control device and its successful application to eight patients. The device is removable and allows the patients to empty their bowels naturally. Following the bowel movement and cleaning of the stoma, the device is reapplied. The patient remains continent and experiences a psychological uplift from being able to feel the urge for bowel movements. The application of the device is easy and leads to no complications.
Phonocardiographic Evaluation of Total Artificial Heart Valve Movement. Correlation with Pressure Waveforms
Authors: Anderson Fred L. , Pantalos George M.
Published: November 2008

Abstract: Two categories of inflow and outflow valve closure sounds are present in the Jarvick‐7 model of the Utah total artificial heart. A presystolic inflow valve closure sound occurs at the end of ventricular filling, resulting from a transient rise in intraventricular pressure above that in the atrium. A second inflow valve closure sound follows, associated with the onset of mechanical systole with a rapid rise in intraventricular pressure. A mid‐ to late systolic outflow valve closure sound occurs at the end of ventricular ejection, resulting from a transient fall in intraventricular pressure below that in the aorta. A second outflow valve closure sound follows, associated with the onset of mechanical diastole with a rapid fall in intraventricular pressure. Under operating conditions where either ventricular filling or ejection is not complete, the presystolic and midsystolic sounds are absent. Thus, regulated heart driver parameters as well as preload and afterload to the extent that they influence ventricular filling and emptying will determine the presence and sequence of valve sounds.
Repeated Membrane Plasma Separation with On‐Line Sorbent Treatment of Plasma in the Conscious Rat
Authors: Ryan Calvin J. , Pusey Charles D. , Aslam Mohammed , Gaylor John D. S. , Maini Roshan , Courtney James M.
Published: November 2008

Abstract: Repeated membrane plasma separation with on‐line sorbent treatment of plasma was performed in unrestrained and conscious rats, thus avoiding the possible effects of repeated stress and exposure to anesthetic agents. The procedure was well tolerated, even after four consecutive perfusions. Blood flow was 0.7 ml/min, with a transmembrane pressure of 18.6 mm Hg and plasma filtration rate of 0.21 ml/min. This allowed 12 ml of plasma (>1 plasma volume) to be treated within 1 h. Levels of albumin, immunoglobulin G, and C3 remained constant during each perfusion and were not significantly different from those of animals subjected to control procedures. Results obtained from filtrate were comparable at 15 and 60 min with values obtained from whole blood, with sieving coefficients of ˜1. Leukocyte, erythrocyte, and thrombocyte counts remained unchanged during each plasma perfusion. A progressive rise in leukocyte counts occurred following successive perfusions, but this was true also of animals subjected to control procedures.
Technical Requirements for Rapid High‐Efficiency Therapies
Authors: Keshaviah Prakash , Luehmann Doug , Ilstrup Karen , Collins Allan
Published: November 2008

Abstract: Significant reductions in treatment time are possible with rapid high‐efficiency hemodialysis and hemodiafiltration, provided the therapies are implemented so as to maintain adequacy of solute and fluid removal without compromising patient comfort. The key technical elements necessary for such implementation include high blood flow rates, higher efficiency dialyzers/diafilters, ultrafiltration control systems, and bicarbonate as the buffer source. In addition, hemodiafiltration requires schemes to ensure sterility and nonpyrogenicity of the infusion fluid and appropriate balancing of the rates of ultrafiltration and reinfusion. In general, rapid high‐efficiency therapies are technically more complex than standard therapy, and rapid hemodiafiltration appears to be more complex than rapid hemodialysis. The technology required for rapid hemodialysis currently exists, but it needs to be fine‐tuned and integrated for routine application.
Internal Jugular Vein Cannulation with Two Silicone Rubber Catheters: A New and Safe Temporary Vascular Access for Hemodialysis. Thirty Months' Experience
Authors: Canaud B. , Beraud J. J. , Joyeux H. , Mion C.
Published: November 2008

Abstract: Temporary and immediately usable vascular access is a vital need in treating uremic patients. Subclavian vein cannulation, although a major progress, has been associated with significant morbidity and mortality. Accordingly, for the last 2.5 years the authors have been developing an alternative technique consisting of internal jugular vein cannulation (IJVC) with two silicone rubber catheters with a long‐term, proved biocompatibility. One hundred sixty‐five pairs of cannulas were inserted in 153 patients. Mean duration of use was 57 days (1 day to 17 months). More than 3,000 high‐performance hemodialysis sessions were performed. IJVC handling and care were easily managed by nurses. A low incidence of complications was observed: two thrombosis episodes, four skin infections with three septicemia, one air embolism, and one anaphylactoid reaction. No death was related to the technique itself. IJVC offers a new, safe, and reliable temporary vascular access immediately usable for all kinds of extracorporeal treatment.
Vascular Prostheses Performance Assessment of Vascular Prosthesis Failure
Authors: Wesolow Adam
Published: November 2008

Abstract: During 30 years of active participation in clinical vascular surgery and the screening and development of vascular prostheses, >450 different fabrications have been evaluated. Vascular prosthesis retrieval and analysis during this period of time have been systematized, and >40 different causes of failure of vascular prostheses have been classified into six classes: failure of diagnosis, error of implantation, patient contribution, complications of healing, fabrication failure, and infection. Such analyses allow for scientific evaluation, testing development, and the elaboration of performance standards so badly needed at present. Such a task is being organized by American Society for Testing and Materials (ASTM) Subcommittee F04.04 on Cardiovascular Materials and Devices and will require the active participation of all knowledgeable individuals.
Successful Declotting of Arteriovenous Grafts with Local Infusion of Urokinase in Hemodialyzed Patients
Authors: Docci D. , Turci F. , Baldrati L.
Published: November 2008

Abstract: Local infusion of urokinase was used in 15 cases of thrombotic occlusion of polytetrafluoroethylene grafts in 10 hemodialyzed patients. The treatment was successful in all patients except one in whom recurring thrombosis occurred because of junctional stenosis at the venous anastomosis. No relevant side effects were observed. Follow‐up data show that such treatment can significantly prolong the survival of arteriovenous grafts in hemodialyzed patients with otherwise difficult access to the circulation.
Some Achievements from the Soviet‐American Cooperation in Circulatory Assistance and the Artificial Heart: 1981–1984
Authors: Shumakov V. I.
Published: November 2008

Abstract: The U.S.S.R. and United States have cooperated on artificial heart research and development since 1974. The exchange of information and developmental models of the artificial heart continued in the years 1981–1984. Soviet and American scientists also continued to meet regularly on specific projects relating to a variety of activities, including the testing of different heart models and biomaterials and experiments with implantation. Three symposia have been held to share research results and identify additional research problems. Joint collaboration has been both expedient and effective and has accelerated research in this area.
Alterations in Select Immunologic Parameters Following Total Artificial Heart Implantation
Authors: Stelzer Gregory T. , Ward Richard A. , Wellhausen Samuel R. , McLeish Kenneth R. , Johnson George S. , DeVries William C.
Published: November 2008

Abstract: We examined select immunologic parameters in three recipients of a total artificial heart and correlated changes with the clinical course. Two patients remain alive and were studied for 320 and 240 days, respectively; the third died 10 days after implantation. All patients demonstrated transient complement activation immediately postoperatively, as indicated by an increase in plasma levels of C3a des Arg. In the two long‐term survivors, C3a des Arg levels again increased, concomitant with intravascular hemolysis associated with high blood shear rates imposed by the drive system of the heart. All three patients had a marked lymphopenia immediately postoperatively, and the two long‐term survivors demonstrated marked fluctuations in total lymphocyte count. There was a progressive decline in the number of peripheral blood helper/inducer T cells in the two long‐term survivors. A large number of activated (HLA‐DR positive) suppressor/cytotoxic T cells were also noted in these two patients. A progressive decrease in B cells was also observed; however, total IgG and IgM levels were not decreased. No changes in neutrophil phagocytic or respiratory burst capacities were identified. The cause of these changes in lymphocyte populations is not clear; however, they may have impact on the use of this device as a bridge to transplantation and may lead to decreased immunocompetence during long‐term use.
Dialyzer Reuse Following Manual Reprocessing with a New Sterilant, RenNew‐D
Authors: Gagnon Raymonde , Adkar Vinita , Kaye Michael
Published: November 2008

Abstract: Dialysis patients are at risk for toxicity from formaldehyde used in the reprocessing of dialyzers for reuse; therefore, replacing formaldehyde as a dialyzer sterilant would be advantageous. The potential for RenNew‐D as a sterilizing agent was investigated in seven stable in‐center hemodialysis patients over 20 consecutive dialyses with cuprammonium cellulose hollow‐fiber dialyzers. Treatment with RenNew‐D showed no toxicity to patients or dialyzers except for two blood leaks occurring in one patient. The mean number of dialyzer uses was 4.9. In all the dialyzers that passed functional testing small solute clearances were maintained with reuse. The ability of RenNew‐D to improve the bio‐compatibility of reused dialyzers was documented with mean neutrophil counts falling to only 78% of initial values during first reuse of dialyzers processed with RenNew‐D compared with a decrease in neutrophil count to 2% of initial values during first use of the same dialyzers. Our results suggest that RenNew‐D may be a useful alternative to formaldehyde for the purpose of dialyzer reuse. A reuse procedure that includes processing with RenNew‐D is associated with improved biocompatibility, possibly because of maintenance of the blood‐derived membrane coating established during prior dialysis.
Ex Vivo Biocompatibility Evaluation of a New Modified Cellulose Membrane
Authors: Bosch Thomas , Schmidt Baerbel , Spencer Peter C. , Samtleben Walter , Pelger Michael , Baurmeister Ulrich , Gurland Hans J.
Published: November 2008

Abstract: To evaluate membrane biocompatibility, an open loop ex vivo model was designed simulating the hemodialysis procedure. Blood was withdrawn continuously from healthy nonuremic donors, heparinized, and pumped through a module containing the membrane to be studied. C3a generation in the module was determined at various time points comparing the cuprammonium cellulose (CC) membrane and four types of modified cellulose (MC) membrane, each with a different degree of hydroxyl (OH‐) group substitution. In other studies, C3a generation in the ex vivo mode was compared with that during in vivo dialysis. In the ex vivo model, C3a generation with MC membranes was reduced by 70% compared with CC. However, within the MC group, the degree of C3a generation did not correlate with the degree of OH‐group substitution. In vivo studies confirmed the reduced degree of C3a generation with the MC membrane compared with CC. Additionally, validation studies using the CC membrane showed excellent agreement between C3a generation during ex vivo perfusion and in vivo dialysis. The results suggest that a group of new MC membranes causes substantially less complement activation than the CC membrane but that the degree of complement activation with various subtypes of MC membranes is not related to the degree of OH‐group substitution.
Characteristics of Chronically Paced Cardiac Functions in the Congenital Complete Atrioventricular Block
Authors: Nawa Sugato , Kioka Yukio , Shimizu Akira , Tsuji Hisashi , Miyachi Yasuo , Ebara Kazuo , Kino Kohichi , Shigenobu Masaharu , Murakami Taiji , Senoo Yoshimasa , Teramoto Shigeru , Dohi Tsuguaki
Published: November 2008

Abstract: Characteristics of morphology, cardiac function, and cardiac reserve at late state were evaluated at rest, by changing the pacing rates, and after exercise in patients with ventricular pacemakers for isolated congenital complete atrioventricular block. Heart size was reduced statistically after pacemaker implantation, and concentric myocardial hypertrophy was observed. Cardiac pump functions at rest seemed fairly well compensated by increased ejection fraction, but the cardiac index was still lower than that of the normal heart. Responses of cardiac function towards the changing rates were considered satisfactory, and those variables had statistic correlations with the pacing rates. After exercise, significant increase of cardiac pump function and also statistic acceleration of myocardial function were observed. This fact proved that cardiac reserve was good, although the increased cardiac output after exercise was still insufficient without an increase in heart rate. More physiological pacing modes would be required as currently recommended.
Absence of Effect of Heparin on Insulin Secretion
Authors: Moussy F. , Velho G. , Aubert N. , Chenard P. S. , Lepeintre J. , Serne H. , Jozefowicz M. , Reach G. , Freyse E. J. , Friedrich M. , Fischer U.
Published: November 2008

Abstract: Bioartificial pancreatic devices containing isolated islets of Langerhans have been designed, in which the blood of the recipient circulates in contact with an artificial membrane, protecting the islets against immune rejection. This system assumes that heparin, required to prevent blood clotting, does not alter insulin secretion. However, heparin has been Reported to inhibit in vitro insulin secretion by rat islets and to suppress in vivo insulin secretion in dogs. Therefore, the following evaluation was made on the effect of different heparin preparations on insulin secretion, (a) Isolated rat islets of Langerhans were perfused or incubated in the absence or presence of 20 u,μg/ml heparin; insulin secretion in response to a stimulation by glucose 20 μM was not altered by the presence of heparin, (b) Insulin secretion by an insulin‐secreting cell line (RINm5F) in response to leucine and theophylline was not suppressed by heparin up to 100μg/ml concentration. However, an inhibitory effect was observed at 200mUg/ml, which is 100 times higher than the heparin concentration commonly used for therapeutic use. (c) Neither in normal rats nor in dogs did heparin alter portal plasma insulin levels and the increase in plasma insulin following an intravenous injection of glucose. In conclusion, these data do not confirm the formerly observed inhibitory effect of heparin, which can therefore be used for the in vivo evaluation of a bioartificial pancreas.
Rapid Measurement of Dialzyer Clearance as a Function of Molecular Weight
Authors: Klein Elias , Turnham Timothy J. , Ward Richard A.
Published: November 2008

Abstract: The relationship between solute clearance and molecular weight (MW) is an important performance characteristic of hemodialyzers. Traditionally, this relationship has been determined using a range of solutes of diverse properties that require a variety of analytical procedures. We describe a simple method for obtaining clearance as a function of MW using a homologous series of glucose oligomers, continuous from the monomer to the octamer. Using HPLC, single analyses of the inflow and outflow streams of the dialyzer allow the determination of clearances over a MW range of up to 1314 daltons.
Discrepancies Between Serum and Erythrocyte Concentrations of Vitamin E in Hemodialysis Patients: Role of HDL‐Bound Fraction of Vitamin E
Authors: Taccone‐Gallucci M. , Lubrano R. , Bandino D. , Citti G. , Attard‐Barbini D. , Mazzarella V. , Elli M. , Meloni C. , Morosetti M. , Tozzo C. , Antonini R. , Urbinati G. , Giardini O. , Casciani C. U.
Published: November 2008

Abstract: Recently, we have demonstrated that hemodialysis (HD) patients have higher serum and lower erythrocyte concentrations of vitamin E than controls. It is known that transfer of vitamin E from serum to erythrocyte is mostly due to high‐density lipoproteins (HDL). For a better definition of the pattern of distribution of vitamin E in HD patients, we have dosed the amount of vitamin bound to serum HDL fraction. In 8 patients and in 8 healthy controls, we have determined the concentration of serum erythrocyte and HDL‐bound vitamin E. The latest was obtained on an ultracentrifuged HDL fraction. HDL fractions from HD patients have been found to contain larger amounts of vitamin E than controls. The previously described higher serum and lower erythrocyte concentrations of vitamin E in HD patients have been confirmed in the study. The deficit of vitamin E in the membranes of erythrocytes from HD patients has been shown to be the result of increased consumption of the vitamin in the erythrocyte membranes, where it represents the major antioxidant agent. However, the finding of increased amounts of vitamin bound to HDL in HD patients suggests that the transfer of the vitamin to the erythrocyte membranes may also be defective.
A New DNA Immune Adsorbent for Hemoperfusion in SLE Therapy: A Clinical Trial
Authors: Yan Yang , Yao‐Ting Yu , Ji‐Chang Song , Shao‐cheng Qian , Wu‐lie Quan , Xin‐hua Shao , Run‐hai Cui , Jian‐zhi Wang
Published: November 2008

Abstract: This investigation studied the preparation and clinical trial of DNA immunoadsorbent for hemoperfusion in systemic lupus erythematosus (SLE) therapy. DNA was complexed with blue tetralium (BT), then mixed with collodion, and finally adsorbed on macro‐porous spherical polymeric adsorbent. The percentage of DNA thus immobilized was 98‐98.5%, and no release was detected during hemoperfusion. A patient with severe SLE was treated with the above adsorbent in hemoperfusion. The patient was in coma, with high anti‐DNA antibody and abnormal immune complex levels, which fell sharply from 56.34% to 0.8% after 2.5 h of whole‐blood hemo perfusion. There were no major clinical complications, and 2 weeks later, her proteinuria level became normal and immune complex levels were sustained. She was then discharged from the hospital and has been in good health for more than 1 year.