bluuebunny/crossref_metadata_2025 huggingface dataset:
Hollow‐Fiber Dialyzers and Their Pyrogenicity Testing by Limulus Amebocyte Lysate
Authors: Henne Werner , Schulze Helmut , Pelger Michael , Tretzel Joachim , von Sengbusch Günter
Published: November 2008

Abstract: Aqueous extracts of cellulose hollow fibers (CHF) exhibit positive reactions in some Limulus amebocyte lysate (LAL) tests. However, in spite of LAL activity, the extracts produce no fever reaction in rabbits. A comparison of lysates from different suppliers shows pronounced activity differences when extracts of cupram‐monium‐derived CHF are tested. One of the lysates, which is fully reactive against standard endotoxin, shows no reaction with such extracts, nor do CHF extracts diminish its sensitivity to standard endotoxin. Investigations of the cuprammonium process have shown that endotoxins introduced by the linters are degraded and washed out. Other endotoxin introduction, particularly by the process water, has been excluded. Oxidative or acidic degradation of cellulose does not result in the formation of LAL‐reactive material (LAL‐RM). On the other hand, sterile cotton wool shows LAL reactivity, and cellulose acetate regains LAL reactivity when it is saponified. Thus, it appears likely that the LAL‐RM found in CHF is of purely cellulosic origin and crossreacts with a number of commercially available lysates.
Sodium Modeling During Hemodialysis: A New Approach
Authors: Petitclerc Thierry , Man Nguyen‐Khoa , Funck‐Brentano Jean‐Louis
Published: November 2008

Abstract: Sodium volume modeling during hemodialysis encounters several difficulties. First, the actual sodium distribution volume is the extracellular water, whereas the ultrafiltration flow reflects the variation of total body water. Thus, a two‐pool model must be considered. This will complicate the model by increasing the number of parameters and boundary conditions. An alternative is to consider the total body water as the apparent distribution volume of loaded or removed sodium, which leads to a single‐pool model. Second, convective sodium transfer induced by ultrafiltration is not negligible compared with diffusive sodium transfer. Therefore, sodium transfer modeling must simultaneously take into account the diffusive and the convective part, with the coupling part related to both processes. Third, the Donnan effect due to nondiffusible anionic plasma proteins modifies the sodium transfer through the membrane. Adequate sodium volume modeling should be a compromise between oversimplification, resulting in discrepancies between calculated values and experimental data, and overcom‐plexity, involving a great number of parameters and boundary conditions, which leads to a model unsuitable for clinical application. A single‐pool model is proposed, with only one parameter that is estimated during the first period of the hemodialysis session.
Chronic Hemodialysis in End‐Stage Lupus Nephritis: Changes of Clinical and Serological Activities
Authors: Pahl M. V. , Vaziri N. D. , Saiki J. K. , Upham T. , Ness R.
Published: November 2008

Abstract: The available data on the clinical and serological activities of systemic lupus erythematosus (SLE) in dialysis patients with end‐stage lupus nephritis are limited. The clinical and serological parameters in 12 such patients prior to, at the onset of, and an average of 31 months after the institution of hemodialysis were retrospectively compared. One of the patients died of cardiopulmonary arrest within 1 week after institution of hemodialysis. All patients were clinically and serologically active prior to the onset of end‐stage renal disease (ESRD). With the onset of ESRD, 2 of the 10 patients exhibited complete clinical and serological remission, and 2 patients showed clinical remission with persistent serological activity. After an average of 31 months on dialysis, the number of patients in total remission rose to 4 of 11, and the number of clinically inactive but serologically active patients was 1 of 11. Significant clinical and serological activities persisted in 6 of the 11 dialysis patients, requiring low dose steroid therapy in 3. The authors conclude that the clinical and serological activities of SLE decrease with the onset of ESRD and the institution of dialysis, leading to complete or partial remission in the majority of patients.
Prolonged Left Ventricular Dysfunction Induced by Sequential Multifocal Ischemic Infarcts in Dogs
Authors: Polanski Jerzy , Mandell Gerald , Wasfie Tarik , Freed Paul S. , Yoshizu Hiroshi , Stein Paul D. , Sabbah Hani N. , Kantrowitz Adrian
Published: November 2008

Abstract: A method of creating multifocal ischemia in animals leading to left ventricular (LV) functional impairment is described. In a series of 10 mongrel dogs, electrodes were implanted in multiple branches of the coronary arteries. Subsequently, in seven animals, an 800‐μA anodal current was applied for 3 h repeatedly over a span of 4–9 weeks. After current application, serum creatine kinase cardiac isoenzyme increased by 12.2 ± 4.6 U/ L (p < 0.01) and ischemic electrocardiographic changes were consistently present. After an average of 10.7 current applications, all animals were tachypneic on mild exertion. Repeated measurement of LV function demonstrated a substantial reduction in cardiac reserve. No significant changes in three control animals were observed. The animals were sacrificed 80 days (range 49–108 days) after the initial current application. Presacrifice cineangiography and postmortem examination disclosed coronary artery occlusions, stenoses, recanalizations, and collateralization in the distributions expected on the basis of the time elapsed since electrode activation. In all cases, the myocardium exhibited diffuse fibrosis. This method reliably brings about multifocal myocardial ischemic changes in dogs and may provide a chronic LV failure model particularly suitable for the evaluation of LV assist systems.
A New Perfusion Circuit for the Newborn with Lung Immaturity: Extracorporeal CO2 Removal via an Umbilical Arteriovenous Shunt During Apneic O2 Diffusion
Authors: Schmidt Stephan , Dudenhausen Joachim W. , Langner Klaus , Laiblin Christian , Saling Erich Z.
Published: November 2008

Abstract: In spite of improved prophylaxis and therapy, the respiratory distress syndrome is still a major cause of morbidity and mortality in premature babies. Owing to the fact that a number of patients are unresponsive to other methods of neonatal care, an increasing number of perinatal centers have started to treat this group of patients with extracorporeal membrane oxygenation successfully. To make the extracorporeal gas exchange more practicable for the neonate directly after birth, a modification of this method using an umbilical arteriovenous shunt for CO2 removal in apneic premature lambs as an animal model was evaluated. A miniaturized low‐resistance extracorporeal circuit that is totally incorporated in a regular intensive care baby incubator was developed. The benefit of using extracorporeal CO2 removal in very low birth weight newborns could be a conditioning of the premature lung during a short period of bypass, after which ventilation at nontraumatic pressures and nontoxic O2 concentrations would become possible.
Analytical Comparison of Single‐Pass and Dead‐End Operation in Cascade Filtration Plasmapheresis
Authors: Lysaght Michael J. , Samtleben Walter , Schmidt Baerbel , Gurland Hans J.
Published: November 2008

Abstract: Derived mathematical models are employed to compare cascade filtration plasmapheresis in the deadend and single‐pass formats. The high filtration fraction and low sieving coefficients associated with single‐pass cascade filtration are shown to require treatment of the retentate concentration profile in an integrated rather than a length‐averaged fashion. The models are best applied to specific simulations, but in general predict that (a) for a given membrane, the dead‐end format will yield a higher albumin recovery but a lower macroglobulin rejection than single pass; (b) the single‐pass format is more suited to loose membranes and the dead‐end to tight membranes; and (c) in the single‐pass but not the deadend format, solute recovery is conveniently independent of the quantity filtered. Agreement between predicted and measured performance is good, although a larger data base would be required for complete validation of the models.
Tactual Perception of Speech‐like Stimuli with an Electrocutaneous Vocoder
Authors: Eilers Rebecca E. , Bull Dale H. , Oller D. Kimbrough
Published: November 2008

Abstract: A deficiency in current tactual vocoder designs is the relatively poor transmission of rapid spectral changes (formant transitions). To understand better the application of electrocutaneous tactual stimulation as a basis for an artificial hearing system, the tactual discrimination of rapidly changing patterns was studied. Stimuli were presented on a belt containing 32 electrodes that was worn in a linear array 5 cm above the navel. Bipolar pulse trains (height 10 mA; width 13 μs) of specified frequencies (200, 400, or 1,000 Hz) were presented sequentially to adjacent electrodes to simulate a tactual vocoder equivalent of simple frequency transitions. Discrimination of the direction of stimulation movement (i.e., stimulation on the belt to either a subject's left or right) was assessed with one experienced subject as a function of both electrode number (four or eight electrodes) and stimulation frequency. Identification of the direction of stimulation movement was influenced both by the number of stimulus channels and by the frequency of electrocutaneous stimulation. These preliminary results indicate that the discrimination of formant trajectory transmitted in an electrocutaneous vocoder scheme is within the temporal limits typically imposed by natural speech.
Studies on Circulatory Stability During Bicarbonate Hemodialysis with Constant Dialysate Sodium Versus Acetate Hemodialysis with Sequential Dialysate Sodium
Authors: Schilling Holger , Lehmann Heike , Hampl Hannelore
Published: November 2008

Abstract: Eight stable patients on maintenance hemodialysis were studied while undergoing (a) acetate hemodialysis with a sequential dialysate sodium concentration from 147 to 137 mEq/L (SNa‐HDA) and (b) bicarbonate hemodialysis with a constant dialysate sodium concentration of 140 mEq/L (HDB). Circulatory behavior was observed during both of these methods, and both were found to allow a high volume removal. However, as a consequence of the high sodium load during SNa‐HDA, volume was shifted from the extra‐ to the intravascular space. This stabilizing effect on the circulation disappeared with the sequential decrease of dialysate sodium concentration (despite a constant plasma sodium concentration of ˜140 mEq/L), which was concomitant with a significant decline of the mean arterial blood pressure and an inadequate compensation of the metabolic acidosis. In contrast, a better circulatory response to comparable volume removal was found during HDB, expressed by a stable mean arterial blood pressure in the presence of well‐balanced arterial acid‐base values.
Innervation of Atrial Stumps in Calves Living with the TNS‐Brno II Artificial Heart
Authors: Doležel Svatopluk , Vašků Jaromír , Hartmannová Brigita , Filkuka Jaroslav , černý Jan , Dostál Miloslav , Sládek Tomáš , Urbánek Erich
Published: November 2008

Abstract:The remnant stumps of the atria in six calves surviving with the artificial TNS‐Brno II methacryiate heart for up to 5 months were examined by means of the Bodian silver‐impregnating technique and by the formalin‐induced fluorescence technique visualizing noradrenaline in monoaminergic nerve terminals. The degeneration of the nerve terminal system detected in animals surviving for 2 days and 1 week was followed by regeneration of the vegetative nerve system in four animals surviving for >1 month. Moreover, thick myelinated nerves afferent in character were detected within the atrium of one animal surviving for 5 months.
The Present and Future of Cardiac Assist Devices
Authors: Watson John T.
Published: November 2008

Abstract: This article describes the status of development of an implantable electrically powered ventricular assist device designed for a minimum of a 2‐year operation in patients with advanced heart failure. While these devices are envisioned for chronic support of the failing circulation, air‐driven blood pumps have been used to provide life support to patients with acute ventricular dysfunction produced by a reversible myocardial injury of unknown origin. The physical and hemodynamic characteristics of the mechanical circulatory support devices are detailed. Clinical indications and results are provided on patients treated with temporary ventricular assist devices. Long‐term follow‐up of some patients has demonstrated sustained improved cardiac function for up to 5 years after treatment. Reperfusion injury and postischemic myocardial depression are discussed as two possible etiologies of acute ventricular dysfunction. In the summer of 1984, investigators began a collaborative program to test the engineering reliability of implantable devices as well as their performance in animals. This 3‐year Device Readiness Program had a goal of demonstrating an 80% reliability with a confidence interval of 70%. In the future, the implantable device will be evaluated clinically in selected patients to investigate its ability to support circulatory functions and the results of host‐device interactions. These devices have potential both as experimental tools in studies of heart and vascular disease and in the treatment of patients with intractable heart failure.
Clinical Validation of a Predictive Modeling Equation for Sodium
Authors: Man Nguyen‐Khoa , Petitclerc Thierry , Tien Nguyen‐Quang , Jehenne Guillaume , Funck‐Brentano Jean‐Louis
Published: November 2008

Abstract: Changes in plasma sodium (Na) concentration during hemodialysis were predicted by changes in Na concentration of the dialysate at equilibrium with the plasma, according to the formula C′1=CD‐(CDD‐ C′0) [(V0‐ QPt)/V0]A/QF, where C′0 and C′t are the Na concentration of the dialysate at equilibrium with the plasma at times 0 and t, respectively; QF is the ultrafiltration flow rate; V0 is the initial total body water; and CD is the Na dialysate concentration. This modeling involves only one parameter, A, which is the effective sodium dialysance and depends on the dialyzer, the QF, the plasma water flow rate, and the actual Donnan coefficient. Parameter A was evaluated after 1 h of dialysis. Seven routine 4‐h dialysis sessions were performed in which the Na concentration of dialysate at equilibrium with the plasma was measured at varying times. The mean (± SEM) difference between predicted and measured values was ΔC= 0.5 ± 0.2 mmol/L. These data support the validity of the model that allows the monitoring of Na dialysate concentration to obtain a prescribed Na plasma concentration at the end of a dialysis session.
In Vivo Comparison of Different Algorithms for the Artificial Beta‐Cell
Authors: Fischer Uwe , Detschew Wesselin , Jutzi Erich , Albrecht Günther , Abel Peter , Salzsieder Eckhard , Freyse Ernst‐Joachim , Frenzel Sabine , Lemke Klaus
Published: November 2008

Abstract: Using an extracorporeal artificial beta‐cell in chronically diabetic dogs, the effects of four different mathematical models of glucose‐controlled insulin dosage were compared: the Biostator algorithm (quadratic equation), Toronto algorithm (hyperbolic tangent function), Karlsburg algorithm (modified first‐order derivative controller), and Ilmenau algorithm (second‐order linear difference equation). The constants of all formulas implemented for the artificial beta‐cell were obtained by regression analysis of paired blood glucose and plasma insulin data from normal control animals. Thus, they were biologically equivalent for all formulas. The patterns of blood glucose, insulin doses, and plasma insulin before, during, and after an intravenous glucose infusion test performed during the glucose‐controlled insulin infusion showed no significant differences between the experimental groups subjected to the different algorithms. However, in no case were really normal blood glucose response curves restored by the artificial beta‐cell. This might be due, first, to the fact that the algorithm parameters were not adapted to the actual individual insulin responsiveness, second, to the unphysiological peripheral venous route of insulin administration, and, third, to the lack of appropriate adaptation of the animals to normoglycemia.
Relationship Between Mechanical and Hydrodynamic Properties of Bioprosthesis Produced from Canine Aortic Valve
Authors: Sato M. , Maeta H. , Okamura K. , Ohshima N.
Published: November 2008

Abstract: Static tensile, stress relaxation, and hydrodynamic tests were carried out to investigate the relationships between the mechanical deformation or stiffness of heart valve leaflets and the opening behavior of bio‐prosthetic valves. The specimens used were fresh and glutaraldehyde (GA)‐treated canine aortic valves. The tensile strength depended on the fiber orientation in the leaflet. The deformability of fresh and 0.05% GA‐treated tissues was significantly larger than that induced by 0.1–5.0% GA concentrations according to the stress‐strain curves. The stress relaxation function, which expresses the viscoelastic property, did not show significant differences in the 0.05‐5.0% range of GA concentrations. In the hydrodynamic tests, the opening resistance of fresh and 0.05% GA‐treated valves was less than that of 0.1–5.0% GA‐treated valves. Thus, it was shown that the hydrodynamic valve functions were closely related to the material properties of aortic valve leaflets.
Clinical Thermofiltration: Initial Application
Authors: Nosé Yukihiko , Usami Makoto , Malchesky Paul S. , Emura Muneo , Horiuchi Takashi , Sakamoto Hiroyuki , Smith James W.
Published: November 2008

Abstract: The first clinical thermofiltration procedures (plasma filtration near or above normal physiologic temperature) were performed on a secondary hypercholesterolemia patient. The intent of this filtration scheme is the selective removal of low density lipoproteins (LDL) and maintenance of high density lipoproteins (HDL) and other essential plasma proteins including albumin. The EVAL 4A filter, at a filtration temperature of 37°C, was selected for on‐line thermofiltration. The sieving coefficients of LDL + very low density lipoproteins (VLDL) cholesterol, HDL cholesterol, and albumin were 0.02, 0.75, and 0.78, respectively. These results are comparable to in vitro filtration tests using the plasma of the same patient. This system is simple to apply and does not require replacement solution. Compared with plasma exchange, a high return of HDL and other essential plasma solutes can be returned to the patient by this method.
Immunomodulation: Bioengineering Aspects
Authors: Malchesky Paul S.
Published: November 2008

Abstract: Plasmapheresis is generally recognized as a “black box” therapy. Factors effecting the immunomodulating influence of plasmapheresis and their impact on the clinical results include the disease state and stage, associated drug and medical therapies, and the methodology of plasmapheresis. The immunomodulating influence of the methodology of plasmapheresis, including duration of treatment, frequency of treatment, equipment type, materials choice, anticoagulant choice, and volume replacement versus selective removal, has a profound impact on the clinical results. Limitations in the design of controlled trials emphasize the importance of assessing the events occurring within and as a result of the individual black box utilized in plasmapheresis therapy. The analysis and understanding of the immunomodulating influences of the “black box” will prove to be very valuable in the development of better technologies for patient care.
Clearance of a Dialyzer Under Varying Operating Conditions
Authors: Sigdell Jan Erik , Tersteegen Bernd
Published: November 2008

Abstract: The clearance of a dialyzer at zero ultrafiltration and zero inlet concentration in the dialysate was studied for varying dialysate flows. It was found that a practically feasible limit can be set to the dialysate flow, above which the gain in clearance is minimal or negligible, resulting more in a waste of dialysate than in increased mass transport. The results suggest a more economical operation of dialyzers, which is of general interest, as well as of special interest in areas where no on‐line dialysate preparation is used (e.g., because of unreliable water supplies).
Relationship Between Red Blood Cell Lipid Peroxidation, Plasma Hemoglobin, and Red Blood Cell Osmotic Resistance Before and After Vitamin E Supplementation in Hemodialysis Patients
Authors: Lubrano Riccardo , Taccone‐Gallucci Massimo , Mazzarella Valentina , Bandino Donatella , Citti Giovanni , Elli Marco , Giardini Omero , Casciani Carlo U.
Published: November 2008

Abstract: It has been reported that increased peroxidation of the polyunsaturated fatty acids in the erythrocyte membranes is one of the causes of chronic hemolysis in uremic patients on hemodialysis and that therapeutic doses of vitamin E are effective in reducing peroxidation, improving the hematocrit. The present study shows how the reduced peroxidation, induced by a course with therapeutic doses of vitamin E, is paralleled by a significant reduction of plasma hemoglobin concentrations at the end of the dialysis and by a significant improvement of erythrocyte osmotic resistance. The findings lead to the suggestion that the administration of tocopherol to patients on chronic hemodialysis for end‐stage renal disease may be beneficial in improving anemia, acting via a reduction of lipid peroxidation of the red blood cell membranes. Whether this can reduce the need for the transfusions can be assessed only with a longitudinal long‐term study, which is also necessary to determine whether the preliminary findings of this report have important clinical applications.
Calcium Carbonate Precipitation in Bicarbonate Hemodialysis
Authors: Klein Elias , Ward Richard A. , Harding George B.
Published: November 2008

Abstract: Calcium carbonate has been observed to precipitate in the fluid pathway of dialysate delivery systems dispensing bicarbonate‐containing dialysates. Such precipitation can occlude the fluid pathway, leading to system malfunction and increased maintenance requirements. We show that commercial supplies of sodium bicarbonate are contaminated by trace amounts of sodium carbonate. This contamination may result in immediate precipitation of calcium carbonate on formulation of the dialysate, since bicarbonate‐containing dialysates, as formulated, are metastable with respect to calcium carbonate. Sparging of the bicarbonate‐containing concentrate with carbon dioxide converts any carbonate to bicarbonate, thus avoiding the formation of precipitates on addition of calcium ions.
Large‐Surface Hemodialysis
Authors: Rotellar Emilio , Martinez Esther , Samso Jose Maria , Barrios Jose , Simo Ricardo , Mulero Juan Francisco , Perez Maria Dolores , Bandrés Silvino , Piñol Juan
Published: November 2008

Abstract: A hemodialysis device with a surface of 5 m2, a blood flow (QB) of 500 ml/min, and a dialysate flow (QD) of 1,000 ml/min has enabled the authors to obtain in 6 h/week the same clearances for urea, creatinine, uric acid, phosphates, and vitamin B12 as has conventional hemodialysis (CH), which takes from 12 to 15 h/week. Twenty‐five patients were hemodialyzed throughout 1 year with CH and another year with large‐surface hemodialysis, 20 with a creatinine clearance (CCr) of 0.5 ml/min and 5 with a CCr between 0.5 and 4.5 ml/min. All followed a free diet and led a normal life. Hemodialysis time was 6 h/week, and the results obtained were equal to those of the previous year with a CH of 12 h/week. The use of a bicarbonate dialysate rich in glucose, with a relatively high level of potassium and sodium, can avoid the disequilibrium syndrome caused by quick hemodialysis and makes possible the removal of excess liquid in only 6 h/week, without disturbances for the patient.
Comparison of Four Methods of Cleaning Hollow‐Fiber Dialyzers for Reuse
Authors: Dennis Melvin B. , Vizzo Joseph E. , Cole James J. , Westendorf Diane L. , Ahmad Suhail
Published: November 2008

Abstract: Four methods of cleaning hollow‐fiber artificial kidneys (HFAKs) for reuse were compared in a prospective study. Each cleaning method was randomly assigned and HFAKs were reused until volume loss was ≥15 ml, unless discarded for other reasons. HFAKs cleaned with 0.3 M sodium hydroxide averaged 14.5 uses, significantly better (p < 0.01) than reverse ultrafiltration (6.4 uses), 3% hydrogen peroxide (5.7 uses), or water flush (4.7 uses). Only 1 of 10 HFAKs cleaned with NaOH was discarded owing to volume loss, whereas 25 of 30 HFAKs cleaned by the other methods were rejected for this reason. To relate changes in solute clearance to volume loss, urea and creatinine clearances were determined on HFAKs cleaned by water flush. By the fifth use the average volume had declined to 86.3% of original, but creatinine and urea clearances were reduced, respectively, to 97 and 95% of the original values.
Low‐Density Lipoprotein Apheresis and Regression of Atherosclerotic Plaque In Vitro
Authors: Orekhov Alexander N. , Khashimov Khairulla A. , Mukhin Dmitry N. , Tertov Vladimir V. , Adamova Irina Yu. , Pokrovsky Sergei N. , Smirnov Vladimir N.
Published: November 2008

Abstract: Short‐term organ culture and primary cell culture of human aorta were used to study the effect of selective removal of low‐density lipoproteins (LDLs) from the surrounding medium (LDL apheresis) on the lipid content of cultured tissue and cells, respectively. LDL apheresis was performed by passing the culture medium through immunosorbent containing agarose‐bound goat antibodies against human LDL. LDL apheresis promoted the decrease of lipids of all classes in the cultured atherosclerotic plaque. However, only the cholesteryl ester level, but not free cholesterol, triglyceride, or phospholipid levels, was lowered in the cells cultured from the plaque. One may thus assume that LDL apheresis facilitates regression of lipoidosis by reducing the content of lipids in atherosclerotic lesions.
Clinical Experience With Bypass of the Left Ventricle Using a Roller Pump
Authors: Lokshin L. , Osipov V. , Khodas M. , Shabalkin V. , Cherepenin L. , Mikhailov Iu. , Arsenev S. , Leonova S. , Rogov K. , Ivanov V.
Published: November 2008

Abstract: Left ventricular bypass (LVB) using a roller pump was performed in 39 patients in the immediate postoperative period. In one group, LVB was performed as a last measure to restore cardiac function. The LVB was temporarily effective in this group, but independent circulation was restored in only 2 of 15 patients. Results were considered unsatisfactory. In a second group, LVB was used immediately when acute left ventricular insufficiency refractory to drug treatment developed. In this group, independent circulation was restored in 17 of 18 patients, demonstrating a therapeutic effect. Overall, cardiac activity was restored in 25 patients; 15 patients recovered and were released. Conditions for the recovery of patients are noted.
Long‐Term Circulatory and Respiratory Support Using Two Artificial Ventricles and a Fluorocarbon Oxygenator
Authors: Ioseliani G. D. , Chilaia S. M. , Guskov I. A. , Chkhaidze Z. A. , Dvaladze G. A. , Khodeli N. G. , Khmelevskoi L. E.
Published: November 2008

Abstract: Using a new heart‐lung machine developed at our Institute, experiments were conducted on dogs, donkeys, and monkeys, providing complete and assisted artificial circulation, assisted oxygenation, and perfusion preservation of the heart. The new apparatus consists of two sequentially mounted artificial ventricles working in an antiphase mode; blood oxygenation is accomplished by a reusable oxygenator with a fluorocarbon preoxygenator. Experimental results indicate that clinical use of the apparatus is promising and deserves consideration. The conditions of perfusion were close to physiological conditions and provided long‐term survival of the animals. Performance in left ventricular bypass was optimized by monitoring myocardial PO2 and the state of the quick‐connect/cut‐off assemblies.
IgE Against Ethylene Oxide‐Altered Human Serum Albumin (ETO‐HSA) as an Etiologic Agent in Allergic Reactions of Hemodialysis Patients
Authors: Grammer Leslie C. , Patterson Roy
Published: November 2008

Abstract: Ethylene oxide (ETO) is used to sterilize hemodialyzers and other medical equipment. In an attempt to confirm a link between ETO and hypersensitivity reactions during hemodialysis (HD) we quantitated IgE and total antibody directed against ETO‐altered human serum albumin (ETO‐HSA) in the sera of 65 hemodialysis patients. In 24 patients who had experienced anaphylaxis during HD. the levels of IgE and total antibody against ETO‐HSA were significantly higher than the corresponding levels in 41 patients who had not. Our data demonstrate an association between the presence of IgE and total antibody against ETO‐HSA and immediate anaphylactic reactions to HD. In further studies we characterized the ETO‐HSA antigen by Immunoelectrophoresis, gel filtration chromatography, and cross‐inhibition immunoassay. Our results suggested that ETO gas can alter HSA and induce new antigenic determinants on the molecule. Recently, we encountered a peritoneal dialysis patient with rash and eosinophilia. Suspecting ETO allergy, we measured serum IgE and total antibody to ETO‐HSA and found both to be present. The data suggest that, in addition to the familiar HD reactions, ETO sensitization might cause other allergic diseases as well.
Ethylene Oxide in Dialyzer Rinsing Fluid: Effect of Rinsing Technique, Dialyzer Storage Time, and Potting Compound
Authors: Ansorge W. , Pelger M. , Dietrich W. , Baurmeister U.
Published: November 2008

Abstract: Ethylene oxide (ETO) is recognized as one of the main causes of dialyzer‐associated hypersensitivity reactions. We studied the amount of ETO in the rinsing fluid of ETO‐sterilized hollow‐fiber dialyzers as a function of rinsing technique, dialyzer storage time, and the amount of potting compound (known to be an ETO reservoir) in the dialyzer. The results suggested that the initial 500 ml of rinsing fluid removes much of the residual ETO in the dialyzer. Ethylene oxide extraction was enhanced substantially by rinsing at 37°C versus 5°C. However, considerable amounts of ETO remained in the dialyzer after an initial 500 ml rinse, some of which could be removed by rinsing with an additional 1,500 ml. High concentrations of ETO were measured in fluid that had been recirculated through the dialyzer for 10 min or longer and in fluid that had been allowed to remain in the dialyzer for 10 min under zero‐flow conditions. The amount of ETO in the rinsing fluid decreased markedly as the dialyzer storage time was increased from 4 to 8 weeks and in dialyzers in which a portion of the potting compound had been replaced with a polycarbonate ring. Our results suggest that the dose of ETO administered to the patient at the outset of dialysis can be minimized by rinsing the dialyzer with 2 L of fluid at 37°C and by avoiding administration of rinsing fluid that has been allowed to remain in contact with the dialyzer for more than several, minutes. Use of a long storage interval and use of dialyzers containing reduced amounts of potting material will also reduce the ETO load.
Effect of First and Subsequent Use of Hemodialyzers on Patient Well‐Being: The Rise and Fall of a Syndrome Associated with New Dialyzer Use
Authors: Charoenpanich R. , Pollak V. E. , Kant K. S. , Robson M. D. , Cathey M.
Published: November 2008

Abstract: In a single large dialysis unit in which dialyzers are routinely subjected to multiple use, the incidence rates of intradialytic symptoms during first use and reuse were compared. Dialyses administered during two periods were analyzed: During the first (26,592 treatments), dialyzers were processed by a manual method before both first and subsequent use. During the second (12,395 treatments), dialyzers were processed by an automated machine method before first and subsequent use. During the first (manual processing) period, 12 symptoms were found to occur more frequently during first use than during reuse. The most striking findings related to chest pain (2.8 times more frequent with first use), back pain (6 times), and concurrent chest and back pain (42 times). Thus, a “first‐use syndrome” characterized by chest and back pain was clearly evident. During the second (machine processing) period, the previously noted increased symptom incidence during first use was no longer present. In particular, the incidence of chest pain and back pain was no longer greater during first use than during reuse. Our results suggest that subjecting dialyzers to an automated reuse processing system before first use can markedly diminish the incidence of first‐use syndrome.
Differential Effect of Hemodialysis Membranes on Human Lymphocyte Natural Killer Function
Authors: Kay Neil E. , Raij Leopoldo
Published: November 2008

Abstract: Lymphocytes exposed to cuprammonium cellulose membranes have been shown to exhibit depressed natural killer (NK) function. In the present study we investigated the extent to which three dialyzer membranes of different compositions suppressed human lymphocyte NK activity. Peripheral blood lymphocytes or T cells from normal donors were exposed in vitro to cuprammonium cellulose, cellulose acetate, or polycarbonate dialyzer membranes. After exposure to the membranes, NK activity of the cells was studied by using the NK‐sensitive cell line K562 as targets. All three membranes adversely affected human lymphocyte NK function, with cuprammonium cellulose producing the most (70–80%) and polycarbonate producing the least (10–15%) suppression. Our results suggest that the composition of dialyzer membranes affects the extent to which the membranes impair human lymphocyte function. The use of more biocompatible membranes might lessen the potential clinical impact of abnormal NK function in hemodialysis patients.
The International Apheresis Registry: Results of 1983 Second Pilot
Authors: Malchesky Paul S. , Skibinski Christine I. , Williams George W. , Nosé Yukihiko
Published: November 2008

Abstract: Results of the second pilot of the International Apheresis Registry for 1983 involving 37 centers on four continents are presented. This report is a follow‐up of the initial pilot reported previously and includes the results of 37 additional centers reporting on 659 patients for a total of 5,780 treatments. The results were collected through a single‐page questionnaire. Information gathered included patient demographics, medical history, treatment specifics (type, methodology, access type, anticoagulants, drugs), side effects, response, and payment provider. The data are grouped by regions (East, Europe, and North America). Analysis of the data identifies the regional differences in apheresis usage and treatment specifics, suggesting that an international view of apheresis is more representative of this therapeutic modality than national results, which are highly dependent on the local economics and available technology.
Clinical Evaluation of a New Water Removal Measuring Device in Standard Dialysis
Authors: Munaretto G. , Bonadonna A. , Bisetto F. , Grando R. , Sama C.
Published: November 2008

Abstract: A new device measuring water removal during standard dialysis is evaluated. The filtrate, collected from a small hemofilter inserted into a normal Cuprophan hollow‐fiber dialyzer, was used to evaluate the total water removed from the patient. The device was tested in 46 patients undergoing regular dialysis treatment; the body weight loss ranged from 300 to 5,600 ml for a total of 71 dialysis sessions. Results confirmed the reliability of the device, as the mean prediction error was 5.4%. No influence of the dialyzer blood rest volume on the prediction error was observed. The authors propose this system as an alternative to bed or armchair scales and emphasize its usefulness for experimental purposes.
Development of Extrauterine Fetal Incubation System Using Extracorporeal Membrane Oxygenator
Authors: Kuwabara Yoshinori , Okai Takashi , Imanishi Yukio , Muronosono Etsuo , Kozuma Shiro , Takeda Satoru , Baba Kazunori , Mizuno Masahiko
Published: November 2008

Abstract: Despite the recent progress in perinatal medicine, it is still difficult to manage the extremely immature newborn. A new extrauterine incubation system has been developed using 14 goat fetuses. The goat fetus is surrounded by artificial amniotic fluid and is connected to an extracorporeal membrane oxygenator. The blood is drained from the umbilical arteries and returned to the umbilical vein. The perfused blood is recirculated and ventilated with a mixture of O2, N2, and CO2 gases to obtain a Po2 of 30–35 mm Hg and a Pco2 of 30–35 mm Hg in the umbilical venous blood. Fetal heart rate, blood pressure, electroencephalogram, and several movement parameters are continuously recorded by the polygraph. With this system, the fetuses can be kept under fairly stable physiological conditions for periods up to 165 h. This improved system might therefore become a useful method to manage the ill fetuses and newborns.
Renal Syndromes in the Acquired Immunodeficiency Syndrome (AIDS): Lessons Learned from Analysis Over 5 Years
Authors: Rao T. K. Sreepada , Friedman Eli A.
Published: November 2008

Abstract: Renal syndromes associated with the Acquired immunodeficiency syndrome include: potentially reversible acute renal failure, AIDS associated nephropathy which leads to end stage renal disease, and AIDS developing in patients who are being treated by maintenance hemodialysis. The longitudinal study of 95 patients with AIDS and various forms of renal syndrome at two urban institutions indicates that both acute and chronic renal failure is increasing yearly. While some patients with acute renal failure recover renal function and survive for prolonged period, the mortality of dialyzed patients with irreversible renal failure continues to be unsatisfactory. There is a great need for collecting data from high risk areas to analyze the results of maintenance dialysis therapy in patients with AIDS, to assess the economic impact of uremia therapy, and for long‐term planning of available resources.
Comparison of Rapid In Situ, Regular In Situ, and Ex Vivo Flushing on Hepatic Function
Authors: Castellanos Javier , Toledo‐Pereyra Luis H. , Finkelstein Israel , Kestenberg William , Chapman Mona , Choudhury Sajal
Published: November 2008

Abstract: The efficacy of three flushing techniques on subsequent liver function was assessed using the in vivo isolated liver perfusion model (ILPM). Livers from brain‐dead mongrel dogs were flushed with cold Euro‐Collins as follows: Group I, rapid in situ flushing (10 min); Group II, regular in situ flushing (45 min); Group HI, ex vivo flushing (10 min). All livers were then heterotopically transplanted into recipients, using the ILPM, by anastomosis of the portal vein, vena cava, and hepatic artery to the recipient's portal vein, iliac vein, and iliac artery. Reperfusion followed for 30 min. Laboratory samples collected at 0, 5, 15, and 30 min showed that hepatic function was not altered by ex vivo flushing and was only slightly altered by rapid in situ flushing. Regular in situ flushing proved to be damaging to livers. Histological analysis confirmed these findings. Therefore, either rapid in situ or ex vivo flushing can be safely used by the transplant specialist.
Artificial Endocrine Pancreas (Closed‐Loop‐System for Blood Sugar Control in Diabetes Mellitus): Introduction to the Subject
Authors: Pfeiffer E. F.
Published: November 2008

SUMMARY AND CONCLUSIONS

Clearly, continuous blood glucose monitoring by portable instruments is the only and absolute prerequisite for unprejudiced evaluation of the various strategies for substitution of insulin deficiency in any form of diabetes mellitus. Continuous blood or tissue glucose monitoring remain the prerequisite for reestablishing a satisfactory feedback control mechanism between insulin secretion and blood glucose concentration in any nondiabetic patient. Loss of first‐phase insulin secretion produces defects in regulation of carbohydrate metabolism, as in type II diabetic human subjects. All efforts to solve this important problem are justified.
Influence of the Surface Area of Different Dialysis Membranes on Granulocyte Adherence and Superoxide Generation
Authors: Paul J. L. , Roch‐Arveiller M. , Postaire E. , Man N. K. , Yonger J. , Raichvarg D.
Published: November 2008

Abstract: Granulocyte adherence and superoxide anion generation were investigated in vitro in the presence of dialysis membrane fragments incubated with normal human polymorphonuclear cells. Dialysis membranes made from cellulosic material or non‐cellulosic material like polyacrylonitrile, polymethylmetacrylate, and polysul‐fone were tested. The membrane surface area varied (1–5 cm2) while the membrane surface/polymorphonuclear cells ratio was maintained constant (2 times 106 cells/cm2). The contact of polymorphonuclear cells with increasing membrane surface area generated a significant decrease of superoxide anion generation (5–80% of inhibition) and produced an increase of granulocyte adherence (5–52%). This phenomenon was observed for all the tested membranes, whether opsonized zymosan or phorbol myristate acetate were used as stimuli. Similar results were obtained after washing the dialysis membrane or when polymorphonuclear cells were suspended in homologous serum. In vitro exposure of granulocytes to cellulosic or non‐cellulosic dialysis membranes caused a surface‐area dependent modification of polymorphonuclear functions.
Effects of Pneumatic Artificial Heart Driver on the Rate of Isovolumic Pressure Rise
Authors: Henker Richard , Murdaugh Carolyn
Published: November 2008

Abstract: : The aim of the research was to investigate the effects of three parameters of the artificial heart's performance on the (+) dP/dt max. Specifically, the effects of heart rate, left‐sided drive pressure, and percent systole (the independent variables) on the (+) dP/dt max (the dependent variable) were examined. The study was conducted using a mock circulation which was connected to an artificial heart. Data were collected using the COMDU software developed for the computer which monitors the artificial heart. Stepwise regression analysis was used to test the three hypotheses. Hypothesis one stated the heart rate would significantly effect the (+) dP/dt max. The hypothesis was not supported. Hypothesis two stated the percent systole would significantly effect the (+) dP/dt max. Hypothesis two was also not supported. Hypothesis three stated the drive pressure would significantly effect the (+) dP/dt max. The hypothesis was supported as drive pressure accounted for 4% of the variance in (+) dP/dt max; however, the results were not clinically significant. Limitations in the study were multicollinearity among the independent variables, small sample size, and the inability of the mock circulation to represent human responses.
The Role of Lymphatic Drainage in Peritoneal Mass Transfer
Authors: Hallett Michael D. , Lysaght Michael J. , Farrell Peter C.
Published: November 2008

Abstract: Peritoneal lymphatic drainage has recently been shown to be a contributing factor to both clearance and fluid removal patterns during continuous ambulatory peritoneal dialysis. In this report peritoneal transport equations are derived and compared and contrasted with existing models that ignore this term. It was found that for solutes for which the sieving coefficient may be assumed to equal unity, such as urea and creatinine, the values of the mass transfer area coefficient (KoA) are overestimated by the value of the lymphatic drainage rate. In this instance, corrected KoA may be obtained simply by subtracting lymphatic flow rate from the KoA calculated by traditional methods. For larger solutes, such as (ß2‐microglobulin, for which the sieving coefficient may be assumed to equal zero, the value of mass transfer coefficient was underestimated to varying degrees; however, for values of lymphatic drainage rate <60 ml/h the effect will not be clinically measurable. A theoretical model is used to plot the dependence of net fluid removal on peritoneal lymphatic flow, glucose KoA, and hydraulic permeability. Reduction in net ultrafiltered volume, and hence estimation of transperitoneal ultrafiltration, is directly proportional to accumulated lymphatic drainage.
Plasma Filtration in Couette Flow Membrane Devices
Authors: Beaudoin G. , Jaffrin M. Y.
Published: November 2008

Abstract: This report investigates the effects of transmembrane pressure (Ptm), rotation speed, and membrane characteristics on the performance of a rotating membrane device for separating plasma from whole blood. This device consists of 58 cm2 polymeric membrane rotating at high speed (3,000–4,000 r/min) inside a concentric cylinder and produces a Couette type flow in a gap 0.9 mm thick. Blood enters tangentially at the top, exits tangentially at bottom, and plasma is collected by an axial duct. It is found that this device yields maximum filtration velocities (plasma filtration flux per unit area) in the range of 0.5‐0.8 cm/min, which are 10–20 times larger than those obtained by using hollow fiber plasma filters. This high performance is not due to the effect of centrifugal forces on red blood cells but rather to the very high shear rates, on the order of 20,000 sec‐1, generated in the gap by toroidal flow instabilities (Taylor vortices). When a 0.8 [i.m pore size Nuclepore (polycarbonate) membrane is used, the filtration velocity presents a narrow peak of 0.6 cm/min at Ptm= 10 mm Hg at 3,000 r/min and decreases to 0.35 cm/min at larger Ptm. With a 0.5‐μm pore nylon membrane the filtration speed increases continuously with Ptm and reaches a plateau of 0.5 cm/min.
β‐2‐Microglobulin and Main Granulocyte Components in Hemodialysis Patients
Authors: Haag‐Weber Marianne , Schollmeyer Peter , Horl Walter H.
Published: November 2008

Abstract: Plasma levels of granulocyte elastase in complex with a,‐proteinase inhibitor (E‐α1,‐PI) increased during hemodialysis from 110 ± 10 to 506 ± 66 pg/L using dialyzers made of polyamide, from 95 ± 2.2 to 211 ± 54 μg/rnl with hemophane and from 114 ± 10 to 203 ± 25 using dialyzers made of polysulfone. Plasma lactofemn values were also significantly higher during hernodialysis with polyamide (772 ± 110 μg/L) compared with hernophane (268 ± 2.2) and the polysulfone (278 ± 31 μg/L) dialyzer. After dialysis each dialyzer was rinsed. We found the lowest concentration of lactofenin (902 ± 254 μ/L) and E‐a,‐PI (739 ± 162μg/L) after rinsing polysulfone dialyzers, whereas the highest concentrations were observed after rinsing the polyamide dialyzers (lactoferrin: 2,426 ± 314; E‐a,‐PI: 1,134 ± 144 μg/L). Hemodialysis with polysulfone dialyzers caused significantly lower plasma levels of P‐2‐microglobulin compared with polyamide or hemophane membranes despite significantly lower levels in the rinsing solutions. Our data indicate that low plasma levels of main granulocyte component observed with polysulfone and hemophane dialyzers are not the result of higher membrane adsorption of E‐a,‐PI and lactofemn. These main granulocyte components are not related to P‐2‐microglobulin levels of both plasma and rinsing solutions.