bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pusher‐Plate Type TAH System Operated in the Left and Right Free‐Running Variable Rate Mode
Authors: Takatani Setsuo , Harasaki Hiroaki , Suwa Shuji , Murabayashi Shun , Sukalac Ronald , Jacobs Gordon , Kiraly Raymond , Nosé Yukihiko 
Published: November 2008

ABSTRACTA TAH system utilizing two pusher‐plate type pumps was developed and tested in two calves for 45 and 108 days with excellent results. A Hall effect sensor was utilized to operate each pump with a full stroke at variable rates (VR); each pump was then allowed to run independently at different rates depending on its own preload and afterload. With this system, the animals' atrial pressures were kept to near‐normal levels (less than 10 mmHg). However, significant differences in the left and right pump flows were observed (left higher than right) and they ranged from 5 to 30% of the left flow with a mean of 15%. These flow differences may be due to the bronchial circulation and related shunts. Right pump flows averaged 70 to 95 ml/min‐kg and circulating blood volume ranged from 67 to 95 ml/kg. When various control modes including fixed rate and master‐slave type simultaneously or alternately ejecting VR modes were applied in the same animals and both pump flows were forced to be equal, unphysiological atrial pressures resulted. This result indicates that perhaps left and right flow differences are necessary physiological conditions to regulate the atrial pressures within normal ranges. Metabolic data also indicated that under simultaneously and alternately ejecting modes, A‐V O2 content differences were increased due to decreased right pump flow as compared with those of the free‐running VR mode. The left and right free‐running VR mode of operation imposed minimal constraints on the animals' cardiovascular system and therefore yielded excellent hemodynamic and metabolic results.
Immunoabsorption in an Extracorporeal Plasma Perfusion System: In Vitro Studies
Authors: Burgstaler Edwin A. , Pineda Alvaro A. 
Published: November 2008

ABSTRACTA rechargeable plasma perfusion system developed to remove IgG immunoglobulins is described. Partially purified protein A was covalently bonded on two separate carriers, Sepharose 6MB and carboxyl acrylic beads. Plasma from a patient with IgG multiple myeloma was perfused through the Sepharose‐protein. A column, and this resulted in a maximum removal of 177% of the estimated removal capacity of the column. Plasma from the same source was perfused through the acrylic bead‐protein. A column and yielded an average of 220% of the estimated removal capacity of the column. In addition, plasma from a normal subject and from six patients with various autoimmune diseases was perfused through the Sepharose–protein A column, and varying percent removal was obtained. A detailed procedure for covalent coupling of purified protein A to carboxylated acrylic beads is also given.
Reticuloendothelial System Fc Receptor Function and Plasmapheresis in Systemic Lupus Erythematosus: A Preliminary Report
Authors: Hamburger Max I. , Gerardi Eugene N. , Fields Theodore R. , Bennett Ronald S. 
Published: November 2008

ABSTRACTReticuloendothelial System (RES) Fc receptor‐mediated immune clearance and levels of immune complexes were measured in patients with systemic lupus erythematosus undergoing plasmapheresis. RES clearance defects improved and disease manifestations and levels of circulating immune complexes decreased after plasmapheresis. Patients with initially abnormal reticuloendothelial system function, elevated levels of circulating immune complexes, and active acute illness appeared to respond to plasmapheresis. One patient with normal immune clearance, lacking measureable immune complexes, and manifesting chronic disease remained unchanged.Improvements seen following plasmapheresis were best maintained in patients receiving parenteral cyclophosphamide in the post‐pheresis period. The correlation of clinical response, improved RES function, and decreased levels of immune complexes suggests the interaction of the latter two parameters in disease pathogenesis. Plasmapheresis has an important role as a research tool, and may be of clinical usefulness in a small number of patients with serious complications of systemic lupus erythematosus.
How To Catch Urea? Considerations on Urea Removal from Hemofiltrate
Authors: Lehmann H. D. , Marten R. , Gullberg C. A. 
Published: November 2008

ABSTRACTHemofiltration imitates the first step in the natural function of the kidney. After separation from corpuscular and high molecular weight blood components, a filtrate remains which contains urea together with electrolytes and other low molecular weight metabolites. To use a hemofilter in a recirculating closed‐loop system, a big quantity of urea must be eliminated.A survey of published attempts to solve this problem is presented. Reasons are given for the difficulty to eliminate urea directly from dilute aqueous solutions. Explanations for ambiguous results of some reactions proposed for urea removal are discussed. The concept of hard and soft acids and bases is used to develop demands to the structure of a reagent which reacts preferrentially with urea in aqueous solution. On monomeric model substances—activated aldehydes—this hypothesis is proven in vitro.In spite of the given technical possibility of urea removal, the authors doubt whether solving the problem of urea removal will enable a closed‐loop system for alternative simpler or more economic ways of treating renal failure.
Urea Elimination Using a Cold Activated‐Carbon Artificial TUbulus for Hemofiltration
Authors: Lehmann Hans‐D. , Marten Renate , Fahrner Irene , Gullberg Claes‐A. 
Published: November 2008

ABSTRACTUrea adsorption on active carbon is reversible and temperature‐dependent. Urea adsorption isotherms of different carbons were determined at 0°C and 65°C within the equilibrium concentration range of 1.0–3.4 gm/L. At low urea concentrations considerable differences (3.4–13.0 gm/kg carbon at concentrations of 1.0 gm/L) were found between different types of activated carbon. The overall internal surface area was of minor importance compared to the pore size distribution.Adsorbing at low temperature, desorbing at high temperature, and flushing the carbon adsorber with a limited volume of the liquid to be purified yielded an “artificial urine.“ Compared to the original urea concentration of the filtrate, this “artificial urine“ had an increased urea concentration.From a 36‐liter volume containing 90 grams urea dissolved in saline. 18 liters were recirculated at a flow rate of 100 ml/min. The influence of adsorption and desorption time intervals was evaluated. After one to one and a half hours the carbon was saturated with urea. After saturation, about 1.4 grams urea were eliminated per cycle. In the “artificial urine“ urea concentrations of up to 4.5 gm/L were found when the original solution contained only 2.5 gm/L. In the “patient“ volume the urea concentration decreased from 2.5 gm/L to 1.9‐2.1 gm/L. Within three hours a total of 22 grams of urea was removed by 3 ± 120 grams activated carbon corresponding to removal of 50% of the urea passing the “artificial tubulus.“The advantage of this system is that after priming, no additional physiological solution would be necessary. The necessity of excessive safety controls, additional electrolyte adjustment, energy demand in the form of direct current, and great amounts of waste in solid form lead to the conclusion that for intermittent hemofiltration treatment, commercially produced and controlled infusion solution is preferable.
Hemodialysis Therapy for Psoriasis
Authors: Chugh Kirpal S. , Kumar Bhushan , Pareek Surinder K. , Kher Vijay , Singhal Praveen C. , Lai Madan , Sharma Lakshmender 
Published: November 2008

ABSTRACTTwenty‐five patients with extensive plaque psoriasis resistant to conventional treatment were evaluated for study of the effects of dialytic therapy on the skin lesions. Twenty patients were dialyzed twice a week for six hours each time with a 1.0 m2Cuprophan membrane dialyzer. Eighteen patients responded to this therapy with regression of skin lesions. Twelve of them have not developed recurrence of lesions during a followup period extending from 6 to 27 months. A few new lesions were observed after two to six months in four patients, but the lesions were not severe enough to justify reinstitution of dialysis. Two patients developed relapse within two months after cessation of dialytic therapy. One of them was started on dialysis a second time and this was followed by remission of lesions. Five patients were taken as controls and were treated with other modes of therapy including sham dialysis, ultrafiltration without dialysis, or systemic heparinization before they were taken on the dialysis program. Whereas sham dialysis and systemic heparinization had no effect on the skin lesions which responded later to dialytic therapy, the ultrafiltration procedure was followed by partial regression of psoriasis. Dialysis appears to have a definite role in the treatment of psoriasis.
Portable Artificial Kidney with Advantages of Hemodialysis, Hemofiltration, and Hemoperfusion
Authors: Shettigar U. R. , Reul H. 
Published: November 2008

ABSTRACTThe FDA (filtration, dialysis, adsorption) system developed in the present study operates on the principle of simultaneous filtration of blood and dialysis against its purified filtrate, the filtrate being purified by a multi‐adsorption system. The filtration of blood is done using a hemofilter which permits clearance of solutes up to 50,000 daltons and easy removal of excess fluid overload under minimal osmotic imbalance conditions. The clearance of small solutes in the above pure‐convective filtration process is enhanced by returning the purified filtrate to the hemofilter which introduces an additional diffusive mass transport to the otherwise pure‐convective process.The purification of the filtrate is done by 3 kg charcoal and 450 gm of cation exchanger in the Ca++ and Na+ form. Sufficient urea binding is achieved by raising the post‐treatment urea level from 50 mg% to 150 mg% which may be justified as the blood urea level below 300 mg% was found to be nontoxic by others. By this procedure, about 40 gm urea is removed per treatment by 3 kg charcoal and 3 to 4 liters of excess fluid discarded. Three kg of charcoal is found to bind an adequate amount of phosphate, thus eliminating the use of phosphate binders, such as alumina, which is a toxic material. The ion exchangers in the Ca++ and Na+ form bind an adequate amount of K+ without altering Na+ and Ca++ levels. The filtrate purification cartridge can be easily regenerated and sterilized, if necessary, thus making it inexpensive. A comparison of the FDA system with other systems clearly shows that it has the advantages of HD, HF, and HP while the major disadvantages of HD, HF, and HP are eliminated in the FDA system.
A Computerized Model to Analyze Transcellular Fluid Shift During Hemofiltration
Authors: Kimura Genjiro , Satani Makoto , Kojima Schunichi , Kuroda Kazuaki , Itoh Keiichi , Ikeda Masao 
Published: November 2008

ABSTRACTUsing urea and inulin as markers, we have developed a simple method to calculate intracellular and extracellular fluid volume in patients before and after hemofiltration therapy. During conventional hemofiltration using substitution fluid with a Na+ concentration of 140 mEq/L, a decrease in extracellular fluid volume was noted whereas the intracellular fluid volume was unaltered. Furthermore, we have developed a computerized mathematical model to analyze transcellular fluid shifts during hemofiltration. This model also indicates a decrease in extracellular fluid volume only, the intracellular fluid volume remaining unchanged. High‐Na+ hemofiltration using substitution fluid with an Na+ concentration of 160 mEq/L has enabled us to remove fluid from both intracellular and extracellular compartments. Thus, high‐Na+ hemofiltration is expected to normalize the intracellular hydration in uremic patients, and to reduce the decrease in extracellular fluid volume during hemofiltration therapy. Our data therefore suggest that high‐Na+ hemofiltration could prevent hypotension due to large decreases in extracellular fluid volume by inducing a transcellular fluid shift out of body cells. Our computerized model can be a useful tool in the prescription of the optimal Na+ concentration in substitution fluid for individualized hemofiltration therapy.
A Morphologic Study of Two Types of Porcine Valve Bioprostheses: Comparison of Aortic Wall Thickness
Authors: Culbertson M. R. , Spangler W. L. 
Published: November 2008

ABSTRACTOuter aortic wall morphology and thickness were compared in the Hancock porcine aortic bioprosthesis and the Carpentier‐Edwards porcine aortic bioprosthesis. The overall average aortic wall thickness, the average maximum thickness, the average minimum thickness, and the average variation in aortic wall thickness were greater in the Hancock valve. Differences in preparation technique accounted for the disparities. The tunica adventitia and variable amounts of the outer tunica media were generally removed during processing of the Carpentier‐Edwards valve prior to mounting in the stent. The removal of this tissue at times exposed the deeper collagenous cusp anchor at the commissures. Possible implications of these differences are briefly considered.
Acute Functional Changes of Platelets in Left Ventricular Assist in a Dog Model
Authors: Mori Y. , Kawase S. , Nagaoka S. , Kikuchi T. , Yokoyama Y. , Kusakabe M. , Okawa Y. , Ito K. 
Published: November 2008

ABSTRACTLeft ventricular assist bypass was performed in nine dogs using pneumatically actuated blood pumps fabricated of segmented polyurethane and heparinized hydrophilic polyurethane (H‐USD) newly developed so as to render excellent antithrombogenicity. The survival of the dogs ranged from 1 to 82 days. In all cases, significant reductions in platelet count and in platelet aggregability were observed. Simultaneously, severe hemorrhage from the anastomosed descending aorta occurred four to six hours after the pump implantation. This hemorrhage, leading to death, was not related to systemic heparinization, but was closely related to the mechanical impairment of platelets by the pumping operation. Five days after the pump implantation, complete recovery of the platelet aggregability was observed and no further hemorrhage occurred in the dog that survived for 82 days.
Hematologic Features of Chronic Renal Failure Associated with Spinal Cord Injury
Authors: Vaziri N.D. , Byrne C. , Mirahmadi M. K. , Golji H. , Nikakhtar B. , Alday B. , Gordon S. 
Published: November 2008

ABSTRACTWe examined the available hematologic data on 43 spinal cord injury (SCI) patients with end‐stage renal disease (ESRD) treated with hemodialysis since 1972. A control group consisting of 45 ESRD patients without SCI was included for comparison. Moderate to severe anemia was found in all patients. The observed anemia was generally normocytic, normochromic, and associated with a low reticulocyte response. Transfusion requirement in the SCI group was considerably more than in the control group. There was a high incidence of splenomegaly, splenic amyloidosis, and lymph node enlargement in the SCI group. Lymph node and bone marrow amyloid deposits were found in some SCI patients but not in the control subjects.
In Vitro Evaluation of U. S. and U. S. S. R. Artificial Hearts
Authors: Guskov Igor A. , Itkin Georgii P. , Lokshin Moiseii A. , Shumakov Valeriy I. , Chimoskey John E. , O'Bannon William , Walker William F. , Lloyd John M. , Noon George P. , DeBakey Michael E. 
Published: November 2008

ABSTRACTThis report summarizes the results of the in vitro evaluation of Soviet and American artificial hearts. The devices were tested at the All‐Union Institute of Transplantation and Artificial Organs, Moscow, U.S.S.R., and Baylor College of Medicine, Houston, Texas, U. S. A. These studies were designed to standardize procedures to allow comparison of artificial ventricles of different designs. Also, these studies might provide a means for evaluation of other characteristics such as hemolysis, durability, and reliability. Static and dynamic tests were performed, varying preload, afterload, rate, and systolic and diastolic time intervals. All designs demonstrated comparable function curves with capability of taking over the pressure and volume work of the natural heart.
Preparation and In Vitro Evaluation of a New Extracorporeal Dialyzer with Immobilized Insulin
Authors: Singh Pratap , Goldman José , Jackson Charles E. 
Published: November 2008

ABSTRACTA specific extracorporeal immunoadsorbent system has been developed that has potential application for the treatment of complications related to the presence of plasma insulin antibodies, namely severe insulin resistance and autoimmune hypoglycemia. The immunoadsorbent system described here makes use of a commercially available cellulose‐based, hollow‐fiber hemodialyzer. Optimal conditions for the coupling of insulin to cellulose matrices were found to involve activation with 1,4‐butanediol diglycidyl ether and reaction with insulin at pH 7.4. The insulin‐dialyzer prepared under these conditions contained 35.5 mg to 37.9 mg of insulin which correspond to a theoretical binding capacity of 887.5 to 947.5 units of insulin. Recirculation of human plasma with high insulin antibody titers through the insulin‐dialyzer resulted in the clearance of 82–99% and 50–83% of high affinity and total insulin antibodies, respectively. The clearance of insulin antibodies approached a steady state after 15 minutes of recirculation at a flow rate of 50 ml/min. Regeneration of used insulin‐dialyzers was accomplished by treatment with 0.02Mcitrate buffer pH 3.2, which restored their ability to clear 90% and 40% of high affinity and total insulin antibodies, respectively. The principle of the insulin‐dialyzer may find application in other disease states where removal of specific antibodies or other high molecular weight species may be of therapeutic value.
Hemoperfusion and DNA Synthesis in the Rat Liver Part II: The Effect of Hemoperfusion on DNA Synthesis in the Rat Liver Undergoing Compensatory Hyperplasia after Partial Hepatectomy
Authors: Ryan Calvin J. , Courtney James M. , Blumgart Leslie H. 
Published: November 2008

ABSTRACTAn investigation has been made into whether hemoperfusion over activated charcoal effects the rate of DNA synthesis in the rat liver undergoing compensatory hyperplasia. Hemoperfusion was performed in the unrestrained and conscious rat, thus minimizing any possible effects of stress and eliminating exposure to anesthetic agents. The results demonstrate that hemoperfusion over Norit RBX1 charcoal does not influence the liver to undergo compensatory hyperplasia following partial hepatectomy when hemoperfusion is performed immediately after hepatic injury, and that liver mass, function, and fat content consequent upon partial hepatectomy are also not influenced.
Intraoperative and Immediate Postoperative Management of Calves Undergoing Valve or Total Artificial Heart Implantation
Authors: van der Wey Leo‐Peter , Hastings Wm. Lawrence , Olsen DonB. , Kolff W. J. 
Published: November 2008

ABSTRACTThe intraoperative and immediate postoperative management data were recorded in a series of twelve artificial device implantation operations in calves. Nine of these were valved conduit experiments not requiring cardiopulmonary bypass, and three were total artificial heart implantations in which bypass was needed. The intraoperative and immediate postoperative management procedures of this laboratory are described including anesthesia, respiratory and drug therapy, and cardiopulmonary bypass management. This paper shows how these procedures may aid in reducing the recovery times of research animals.
Electrodialysis and Reverse Osmosis as a Regeneration System for Hemofiltrate
Authors: Hintzen K. , Stiller S. , Brunner H. , Rautenbach R. , Mann H. 
Published: November 2008

Abstract: The separation of urea from the hemofiltrate (or from spent dialysis fluid) must be considered the critical step in all regeneration systems. A promising solution for this problem is the combination of electrodialysis and reverse osmosis. A mathematical simulation of the process and in vitro experiments have been carried out in order to determine operating conditions and design specifications. The experiments confirmed the predicted performance of the regeneration system with respect to the separation of urea and the recovery of electrolytes. As expected, some ionic toxins, such as uric acid, and some middle molecules are recovered also. These substances, however, can be easily removed by a small adsorption cartridge.A combination of ED and RO is a promising solution for the regeneration of hemofiltrate. The separation of neutral uremic toxins, such as urea and creatinine, and the recovery of water and electrolytes are satisfactory. Ionic toxins such as uric acid and some middle molecules will be recovered, i.e., not separated to a certain degree. These substances, however, can be easily separated by adsorption. Trivalent ions like phosphate will be partly separated by the regeneration system, because in ED their rate of transport is lower than that of mono and bivalent ions.The experiments indicate that the ED unit has to be optimized. It would need ˜ 5.7 m2 of membrane area in order to achieve the desired removal. It could be demonstrated, however, that with improved flow conditions in the ED unit, a membrane area of ˜ 1 m2 may be sufficient.A detailed flow diagram of the complete regeneration system is shown in Fig. 9. The ED‐RO system in principle can also be used for regeneration of dialysate.
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 CONCLUSIONSClearly, 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.
An Artificial Neural System for Closed Loop Control of Locomotion Produced via Neuromuscular Electrical Stimulation
Authors: Sepulveda Francisco , Cliquet Alberto 
Published: November 2008

Abstract: The use of neuromuscular electrical stimulation for restoration of gait in spinal cord injured subjects has been seriously pursued by many investigators for the past 15 years. By and large, however, systems to date require the intervention of a person, be it the patient or an observer, and are restricted to control of stimulation onset and termination. Further, existing systems are not adaptable to environmental and patient variations. This work proposes a system that relies on neural computing to determine proper muscle activation patterns from biome‐chanical signals. The intelligent system is trained to perform gait under supervision, after which it can be used to control muscle stimulation in an unknown environment.Computer simulations suggest that the best neural architecture for control of gait is a neural network including units corresponding to movement history. Separate networks for the stance and swing phases, respectively, were found to work better than a single neural network trained on the entire gait cycle. The artificial neural device proposed here also includes a voice recognition system that will allow for voluntary locomotion. A safety circuit has been designed to preclude acceptance of unwanted vocal commands in the latter system.