bluuebunny/crossref_metadata_2025 huggingface dataset:
Kappa opioids promote the proliferation of astrocytes via Gβγ and β‐arrestin 2‐dependent MAPK‐mediated pathways
Authors: McLennan Gregory P. , Kiss Alexi , Miyatake Mayumi , Belcheva Mariana M. , Chambers Kari T. , Pozek John J. , Mohabbat Yasmin , Moyer Robert A. , Bohn Laura M. , Coscia Carmine J.
Published: November 2008

GTP binding regulatory protein (G protein)‐coupled receptors can activate MAPK pathways via G protein‐dependent and ‐independent mechanisms. However, the physiological outcomes correlated with the cellular signaling events are not as well characterized. In this study, we examine the involvement of G protein and β‐arrestin 2 pathways in kappa opioid receptor‐induced, extracellular signal‐regulated kinase 1/2 (ERK1/2)‐mediated proliferation of both immortalized and primary astrocyte cultures. As different agonists induce different cellular signaling pathways, we tested the prototypic kappa agonist, U69593 as well as the structurally distinct, non‐nitrogenous agonist, C(2)‐methoxymethyl salvinorin B (MOM‐Sal‐B). In immortalized astrocytes, U69593, activated ERK1/2 by a rapid (min) initial stimulation that was sustained over 2 h and increased proliferation. Sequestration of activated Gβγ subunits attenuated U69593 stimulation of ERK1/2 and suppressed proliferation in these cells. Furthermore, small interfering RNA silencing of β‐arrestin 2 diminished sustained ERK activation induced by U69593. In contrast, MOM‐Sal‐B induced only the early phase of ERK1/2 phosphorylation and did not affect proliferation of immortalized astrocytes. In primary astrocytes, U69593 produced the same effects as seen in immortalized astrocytes. MOM‐Sal‐B elicited sustained ERK1/2 activation which was correlated with increased primary astrocyte proliferation. Proliferative actions of both agonists were abolished by either inhibition of ERK1/2, Gβγ subunits or β‐arrestin 2, suggesting that both G protein‐dependent and ‐independent ERK pathways are required for this outcome.
Seeking calm water: Exploring policy options for India's water future
Authors: Amarasinghe Upali A. , Shah Tushaar , McCornick Peter G.
Published: November 2008

This paper seeks to identify some promising policy options which could be part of a strategic and holistic effort to address India's future water challenges. Significant increases in agricultural water productivity would be a major factor in reducing the need for developing new water sources. Crop diversification, appropriately targeted to account for the present agricultural systems and available water resources, will increase productivity. Furthermore, much more emphasis needs to be placed on effective management of the groundwater resources through renewed efforts to enhance artificial recharge and conservation. Also, efforts should be revived to improve the existing surface irrigation systems. In particular, systems could be reconfigured to provide a more reliable water supply and allow effective community level management, where appropriate. Finally, while some of the increasing demands from domestic and industrial users will be met by the development of groundwater and reallocation of water from the agricultural sector, this will not be sufficient. Given that such conditions are emerging in states with high economic growth and relatively water scarce basins, this will require the further development of water resources. In some cases, these conditions along with the demand for reliable water for high value crops, will be part of the justification for inter‐basin transfers.
The need for integration of drought monitoring tools for proactive food security management in sub‐Saharan Africa
Authors: Tadesse Tsegaye , Haile Menghestab , Senay Gabriel , Wardlow Brian D. , Knutson Cody L.
Published: November 2008

Reducing the impact of drought and famine remains a challenge in sub‐Saharan Africa despite ongoing drought relief assistance in recent decades. This is because drought and famine are primarily addressed through a crisis management approach when a disaster occurs, rather than stressing preparedness and risk management. Moreover, drought planning and food security efforts have been hampered by a lack of integrated drought monitoring tools, inadequate early warning systems (EWS), and insufficient information flow within and between levels of government in many sub‐Saharan countries. The integration of existing drought monitoring tools for sub‐Saharan Africa is essential for improving food security systems to reduce the impacts of drought and famine on society in this region. A proactive approach emphasizing integration requires the collective use of multiple tools, which can be used to detect trends in food availability and provide early indicators at local, national, and regional scales on the likely occurrence of food crises. In addition, improving the ability to monitor and disseminate critical drought‐related information using available modern technologies (e.g., satellites, computers, and modern communication techniques) may help trigger timely and appropriate preventive responses and, ultimately, contribute to food security and sustainable development in sub‐Saharan Africa.
Degradation–environment–society spiral: A spatial auto‐logistic model in Thailand
Authors: Wahid Shahriar M. , Babel Mukand S. , Gupta Ashim Das , Routray Jayant K. , Clemente Roberto S.
Published: November 2008

In this contemporary interpretation of the widespread land degradation problem in Southeast Asia, it is hypothesized that spatial interplay of environmental and socioeconomic predictors determines the occurrence of land degradation. Village surveys, remote sensing and spatial auto‐logistic modelling of the relationship between degradation and land use dynamics in Lam Phra Phloeng watershed of Thailand enabled 80.2% of land to be classified correctly in terms of the presence or absence of erosion and explained 53.2% of the total variation. Cultivation and dependence on agriculture for livelihood positively and significantly affect degradation. Lack of access to institutional credit and land titles significantly increased the probability of occurrence of degradation. On the other hand, education and social cohesion are negatively associated with the occurrence of degradation. The Relative Operating Characteristic (ROC) curve was used to measures the performance of the model. The calculated area under the curve (0.879) suggests that significant predictor variables in the model can be confidently used to forecast the likelihood of occurrence of degradation and thus to identify priority areas for intervention. Policies to reduce land degradation should include measures to reduce pressure on the land, including alternative income sources. Policies could mobilize capital to invest in encouraging nature‐based tourism and other off‐farm income options.
Artificial Excretion of Weakly Bound Middle Molecules by Hemoanadiafiltration
Authors: Russo Luigi , Russo Anna , Viola Mario , Russo Vincenzo
Published: November 2008

The concept of a subtractive therapeutic intervention in several diseases (shock, acute liver, failure, poisoning) to remove toxic middle molecules (MM) has led to the devising of a particular ultrafiltration system (anadiafiltration) to clear weakly bound MM. Clinical hemoanadiafiltration (HADF) with a polyacrylonitrile filter and in vitro experiments with a series of marker substances, have shown HADF efficacy in clearing MM, irrespective of their molecular weight, with protein binding K between 60 and 150.
Further Studies on the Realization of a Cold Carbon Portable Artificial Kidney
Authors: Giordano Carmelo , Esposito Renato , Leo Vito A. Di , Bello Pierino , Quarto Ernesto
Published: November 2008

Optimal conditions have been determined for the realization of a closed‐loop, cold carbon, portable artificial kidney to depurate the dialysate of urea and other catabolites. It has been noticed that a dialysate flow rate of about 250 ml/min represents an optimal compromise between urea mass transfer through the dialytic membrane and its mass adsorption on cold carbon. Under this condition, the use of a 2‐kg carbon column to remove urea is satisfactory for a routine dialysis treatment. Our experiments have been performed on simulated dialysis. A portable cold carbon artificial kidney requires a cooling unit and a heat exchanger to recover the power necessary to produce the 0°C temperature. A flat heat exchanger, consisting of three superposed plates, with a heat exchange surface of about 0.09 m2 and a total coefficient of thermal exchange, H., of 380 Kcal/m2‐°C‐hour has been chosen. With heat recovery, the cooling power required is 1/3 hp to allow for parasitic cold losses and the power necessary to reach a steady state. All mechanical parts necessary for heating and cooling weigh about 12 kg.
Chronic Hemofiltration Treatment
Authors: Streicher Erich , Schneider Hans , Knödler Ullrich , Müller Holger , Spohr Uwe , Schmidt‐Gayk Heinz
Published: November 2008

Fourteen patients (six males and eight females) have been treated with chronic hemofiltration three times weekly for three to 27 months with the post‐dilution technique. All patients had previously been on regular dialysis treatment. Patients were selected for hemofiltration because of dialysis‐resistent hypertension (eight), symptoms of dialysis discomfort (five), hypertriglyceridemia (five) and poly‐neuropathy (seven). Hypertension improved in six of eight patients, symptoms of dialysis discomfort markedly diminished in all five patients, hypertriglyceridemia did not change consistently, polyneuropathy improved in six of seven patients. Balance studies of Na, Ca and Mg revealed a positive correlation to fluid balance. Phosphate, BUN, crentinine and uric acid increased. Loss of amino acids and protein is negligible. Hormone studies showed a decrease of T3, T4 and TSH though the pituitary‐thyroid axis is intact, possibly indicating a decreased TRH activity. Vitamin D remained unchanged, PTH levels increased, possibly related to a diminished excretion of phosphate and diminished intake of calcium, respectively, during hemofiltration treatment as compared to hemodialysis.
BRNO‐I, An Implantable, Diaphragm‐Type Total Artificial Heart: Technical Aspects of Design
Authors: Hanzelka P. , Krčma V. , Svoboda P. , Trbušek V. , Urbánek P. , Vašk° Jan , Vašk° Jar. , Uráhnek E. , Dostál M.
Published: November 2008

The technical aspects of artificial heart design for experiments on calves are presented in this paper. The object of the design was to verify the basic anatomic and hemody‐namic criteria for the design of more perfect cardiac pros‐theses. Each of the ventricles has a 100‐ml stroke volume and is dismountable. Rigid parts are made of polymethyl‐methacrylate. The inlet valve has the shape of a flap. The outlet valve has two polyurethane reinforcing leaves. The diaphragm is also made of polyurethane. During tests using artificial circulation, a maximum cardiac output of 14.6 L/min was achieved. Typical sensitivity of flow on the atrial pressure is 0.3 L/min/torr at a frequency of 90 pulses per minute.
Influence of Uremic Middle Molecules on Blood Cells
Authors: Ota Kazuo , Sanaka Tsutomu , Agishi Tetsuzo , Nakajima Osamu
Published: November 2008

Uremic middle molecular weight substances are obtained from the ultrafiltrate of plasma of uremic patients. Seven subfractions are isolated by chromatography using Sephadex G‐15 and DEAE 25 A columns. Each subfraction is tested for its inhibitory effect upon lymphocyte blastogenesis and influence upon osmotic fragility of red blood cells. Consequently, subfractions c and d exert notable effects on both lymphocytes and red blood cells. The main constituents of subfraction d are aspartic acid, glycine, glutamine, and cysteine.

It is concluded that uremic middle molecular substances have a deleterious effect upon blood cells. Therefore, hemofiltration, which is advantageous for the removal of middle molecular weight substances, is considered to be a method of choice for uremic patients.
Effects of Different Filter Positions and Combinations in Extracorporeal Circulation
Authors: Krebber Hans J. , Hill J. Donald , Osborn John J. , Iatridis Angelo , Gerbode Frank
Published: November 2008

Even though filtration of the blood return from the coronary suction line has become widely accepted, there is still some question as to the benefit of arterial line filters and combinations of different filter positions. During 29 extracorporeal circulations, blood was sampled at 5, 15 and 30 minutes of bypass and at the end of bypass. All added donor blood was filtered through microporous filters (F1). In 12 instances a coronary suction line filter (F2) was in place and in all instances an arterial line filter (F3) was in place. Blood samples were taken before and after the arterial line filter and from the venous blood. All samples were studied for screen filtration pressure and electronic particle count using apertures from 8 to 120 microns. Particle counts were summarized under two groups: large particles ranging from 12.8 to 120 microns and small particles ranging from 8 to 12.7 microns. The filter combinations FI F2, F1F3 and F1F2F3 were studied. All of the filters were found to be capable of filtering large sized particles: however, slight improvement was seen by using the F1F2F3 combination. A high gradient of the large particle count was found across the arterial line filter. Small particles were found to be derived predominantly from the coronary suction line filter. While the low‐flow coronary suction line filter was well capable of removing particles of small size, no gradient in the particle count was found across the arterial line filter. Combinations of filters did not improve the filtering of small particles.

A significant increase in the number of circulating small particles was found toward the end of bypass. An increasing differential between particles in the arterial line and venous blood was found toward the end of bypass. The number of circulating platelets dropped to 50% of the preoperative number within five minutes on bypass. No differences were found when using different filter combinations.

The filtering of very small particles in the size range of the cellular elements of the blood is still an unsolved problem. With available systems, the Dacron mesh filter in the coronary suction line had the best results due to the lower flow and low velocity, while arterial line filters with high velocity are not capable of removing the smaller particles. Arterial‐to‐venous blood differences in the particle count suggest that some of the micro‐aggregates were removed from the blood within the patient. As the difference became larger toward the end of bypass, i.e., with rewarming of the patient and recirculation through the lung, increased capillary filtration seemed to play an important role.
Controlled Ultrafiltration During Single‐Pass Dialysis with the RP‐6 Dialyzer and Evaluation of Its Time‐Dependent Ultrafiltration Index
Authors: Zelman Allen , Bulloch Edwin , Stephen Robert , Kablitz Carl , Duffy Douglass , Kolff Willem J.
Published: November 2008

A simple and inexpensive method is described for controlling ultrafiltration when using the high flux RP‐6 dialyzer. When the RP‐6 is operated in the co‐current mode and with single‐pass dialysate delivery, (Pbo‐Pdn) can be used to accurately and safely control ultrafiltration. Combined results from ten dialyses indicate there is a pressure‐dependent concentration polarization which affects ultrafiltration as reported previously, and in addition, a time‐dependent effect indicating a more complex dialyzer/blood interaction. The ultrafiltration index decreases linearly with time. The ultrafiltration can be adequately predicted by

Qv=16.1 ml/hr‐mmHg [1–0.0761/hr t] (PBo‐PDo)
Pressure Control of Ultrafiltration Rate with High‐Flux Dialysis Membranes
Authors: Kablitz Carl , Stephen Robert L. , Zelman Allen , Harrow Jeffrey J. , Deeter Barry R. , Kolff Willem J.
Published: November 2008

Control of ultrafiltration with high‐flux dialysis membranes is normally achieved using complex, expensive, volumetric control methods. By using high‐flux dialyzers with distensible membranes (parallel‐plate dialyzers) in the cocurrent rather than in the countercurrent mode, ultrafiltration can be controlled simply and inexpensively by controlling the outlet pressure differential. Since this is the traditional method of ultrafiltration control, only minor, inexpensive equipment modifications are needed. As expected from transport theory, small molecule clearances are lower with cocurrent than with countercurrent flow. They are, however, adequate and superior to those achieved with post‐dilutional hemofiltration (urea clearance > 110 ml/min with cocurrent single‐pass, high‐flux dialysis). Ultrafiltration control with this method is so simple and predictable that clearances at zero net ultrafiltration rates can easily be measured rather than extrapolated. Since dialysate pressure is always positive, no deaeration systems would be needed in dialysis equipment designed for use with co‐current single‐pass, high‐flux dialysis.
Ferritin: A Reliable Indicator of Iron Supplementation in Patients on Chronic Hemodialysis/Hemofiltration Treatment?
Authors: Müller H. A. G. , Schneider H. , Hövelborn U. , Streieher E.
Published: November 2008

Four hundred and forty‐two serum ferritin determinations were performed in 144 patients on chronic intermittent hemodialysis treatment with intravenous iron substitution and/or oral iron substitution. Iron substitution should be done individually according to regular serum ferritin determinations. Intravenous iron substitution is easier to regualte. Iron substitution exceeding 100 mg per month normally leads to a slowly progressing iron overload except in those patients with additional blood loss or on chronic hemofiltration treatment. Iron administration should not be evaluated according to ferritin levels in patients with additional complications such as active hepatitis, tumors, infectious diseases, and operations. In these cases evaluation of iron storage can only be estimated by bone marrow examination.
Dialysis Treatment in Schizophrenia: Two Years Experience
Authors: Splendiani Giorgio , Bruno Vittorio , D'Alessandro Valfredo , Pomero Paolo , Cammà Maria Luigia , Tancredi Maurizio
Published: November 2008

The authors summarize two years trial of dialysis treatment of schizophrenia. Twenty‐five schizophrenic patients were treated with hemodialysis using PAN membranes. The dialysis schedule was: dialyzer: RP 610; blood flow: 250 ml/min; dialysate flow: 500 ml/min; time: 3 hr; vascular access: arteriovenous fistula, femoral vein, antebrachial veins. Dialysis was first performed for three days, repeated after one week, two weeks, three weeks, and one month, and then performed once a month. The drug regimen was never modified or interrupted. The results were evaluated with the Overall and Lorr scale. Nine patients interrupted the treatment early and were not considered; nine patients showed disappearance of psychiatric symptomatology (Overall and Lorr index decreased to 21.8 at 2); non‐significant modifications of the main schizophrenic symptoms were observed in seven patients. According to our trial, dialysis with polyacrylonitrile membranes can modify the psychotic attitude in a group of schizophrenic “dialysis responders.“
Middle Molecular Weight Substances and Tryptophan in Cerebrospinal Fluid of Schizophrenic Patients
Authors: Sperschneider Heide , Spustova Viere , Neumann Jochen , Stein Günter
Published: November 2008

Patients with various forms of schizophrenia were analyzed in this study. Lumbar CSF was collected for fractionation of middle molecular weight substances with simultaneous tryptophan determination. Middle molecular weight substances could not be detected in CSF by measurement at 254 nm. Tryptophan analysis in CSF did not provide any relevant information concerning pathogenesis.
Establishing a Therapeutic Pheresis Program
Authors: Cona Jeanne A.
Published: November 2008

Pheresis techniques have been used to collect large quantities of specific blood components from single donors for many years. These techniques have been modified to methods for therapy in certain disease processes. The adaption of pheresis to a type of therapy requires that many factors be taken into consideration and the following describes these factors.
Axial Changes of Blood and Plasma Flow, Pressure, and Cellular Deposition in Capillary Plasma Filters
Authors: Zawicki I. , Malchesky P. S. , Smith J. W. , Harasaki H. , Asanuma Y. , Nosé Y.
Published: November 2008

The ability to separate plasma on‐line from whole blood by membranes has generated interest in applying this process to source plasma collection and to the therapeutic treatment of various disease states. The availability of capillary membrane devices in particular has prompted investigations in these areas. The deposition of blood cellular elements has required the investigation of those parameters related to fluid and mass flux. Analytical solutions relating blood flow rate, filtration rate, and pressure and deposition with respect to axial distance have been obtained. Comparison of these solutions with preliminary experimental results have been made. Results indicate that the deposition parameter versus distance from the inlet is a very sensitive function of capillary membrane properties and operating conditions. Plasma fluxes are also highly dependent on blood, membrane, and filter properties and operating conditions.
Accessible Plasma Exchange Using Membrane Filter ‐ A Successfully Treated Case of TTP With Repeated Plasma Exchanges
Authors: Shinoda A. , Kitada H. , Suzuki S. , Kurihara S. , Saito Y. , Yuri T. , Ishikawa I.
Published: November 2008

Plasma exchanges with a hollow‐fiber type plasma filter were attempted in a variety of diseases. The unit was easily assembled and the procedures were safely carried out by our dialysis personnel after some instruction.

Approximately 2 liters of fresh frozen plasma were used during each plasma exchange and about the same amount of plasma was removed from the patient in 1.5 to 2 hours. This resulted in 66% replacement of patient's albumin on one occasion.

Fifty‐four plasma exchanges were done in seven patients. The procedure was well tolerated by all patients with only occasional muscle cramps or itching, which were treated with calcium gluconate infusion or antihistamines, respectively.

A successfully treated case of TTP in which we used repeated membrane plasma exchanges combined with conventional treatment is also Reported.
Plasma Exchange and Immunoadsorption for Removal of Antibodies Prior to ABO Incompatible Bone Marrow Transplant
Authors: Bensinger William I.
Published: November 2008

ABO incompatible allogeneic bone marrow transplants can be performed successfully to treat patients with leukemia or aplastic anemia. These transplants carry no great risk of rejection or graft‐versus‐host disease, however, some method must be used to avoid acute hemolysis at the time of infusion of ABO incompatible marrow. We have used successfully large volume plasma exchange to remove anti‐A or anti‐B antibodies prior to marrow infusion. More recently we have used immunoadsorbent columns containing synthetic A or B antigen specifically to remove anti‐A or anti‐B antibodies in lieu of plasma exchange. These columns are better tolerated than plasma exchange where allergic reactions are common.
Successful Treatment of Fulminating Complications Associated with Extensive Rhabdomyolysis by Plasma Exchange
Authors: Kuroda Mitsuhiko , Katsuki Kenichi , Uehara Hajime , Kita Tohru , Asaka Satoshi , Miyazaki Ryoichi , Akiyama Takashi , Tofuku Yohei , Takeda Ryoyu
Published: November 2008

The first successful treatment by plasma exchange of acute renal failure and disseminated intravascular coagulation, as well as liver and central nervous system damage, was achieved in two patients with severe multiorgan damage associated with extensive muscle tissue damage caused by heatstroke and/or electrical injury. Substances derived from damaged muscle tissue, such as myoglobin and enzymes, were efficiently removed by a cellulose acetate membrane filter. Improvement of consciousness, disturbance, coagulation disorder, and renal failure were observed. The disorders associated with extensive rhabdomyolysis seem to be a promising indication for this therapy. Plasma exchange with a membrane filter is useful for treatment of patients with renal failure, being readily connected on‐line with conventional dialysis.
Pseudoendothelium Formation in Expanded Polytetrafluoroethylene Grafts Implanted in the Inferior Vena Cava of Normal and Defibrinogenated dogs
Authors: Ishimaru Shin , W‐O Eva Berglin , Hansson Hans‐Arne , Teger‐Nilsson Ann‐Catrine , William‐Olsson Göran
Published: November 2008

The outgrowth of endothelial cells in an expanded polytetrafluoroethylene graft implanted in the canine inferior vena cava was studied by scanning electron microscopy. The adjacent endothelial cells of the vena cava started to invade the anastomotic area three days after the implantation and reached approximately the central part of the 2‐cm‐long graft after 21 days. There was no obvious difference in the process of endothelialization between the control group and the moderately defibrinogenated group, in which the fibrinogen concentration was at most 0.72‐0.87 gm/L. A slight delay in the outgrowth of endothelial cells was noted within the first seven days in the severely defibrinogenated group, in which the fibrinogen concentration was below 0.40 gm/L. After 70 days, all grafts were completely covered by endothelial cells. The structural difference of the mural thrombus resulting from reduced fibrin formation might be a major factor influencing the endothelium formation.
Mass Transfer in Membrane Plasma Exchange
Authors: Randerson David H. , Blumenstein Matthias , Habersetzer Rupert , Samtleben Walter , Schmidt Baerbel , Gurland Hans J.
Published: November 2008

In vitro and in vivo sieving coefficients (SC) have been determined for a spectrum of proteins ranging in molecular weight from 66,500 daltons (albumin) to 2.4 million (β‐lipoprotein) daltons for three commercially available membrane plasma separation devices: the Plasmaflo 01, Plasmaflo 02, and Plasmaflux. A model relating serum level of a protein to pretherapy level, plasma volume, plasma filtration rate, membrane SC, and duration of treatment has been used to investigate the influence of SC on exchange efficiency. Comparison of predicted and clinically obtained reductions in serum solute levels demonstrated the validity of the model. The results of the analysis suggest that all three plasma separators are capable of delivering equally acceptable therapy. The model further demonstrates the decreasing effectiveness, and increased cost in terms of replacement fluid per unit of solute removed, with prolonged treatment times.
The Thin‐Film Adsorber Hemoperfusion Device: Development and Evaluation of Clearance Characteristics
Authors: Cooney David O. , Kane Robert P.
Published: November 2008

A novel hemoperfusion device was developed by embedding powered activated charcoal in thin (150 μm) films of cellulose nitrate. These films were sprinkled with small particles of granular charcoal and wound into spools, which were then placed in a plastic housing. The use of powdered charcoal exploits the enormous rate‐of‐uptake advantage of powered charcoal over the granular sorbents found in other hemoperfusion devices. The granular carbon sprinkled on the films was primarily to provide spacing between adjacent film layers for adequate fluid flow; the granules did enhance long‐term uptake in addition. Clearance tests with this novel “thin‐film adsorber,” using sodium salicylate, sodium barbital, and creatinine, showed that its rate of solute adsorption, particularly at early times, was consistently very high. This type of hemoperfusion device is a promising alternative to the granular‐sorbent types of devices currently available, especially when maximal solute removal during the early stages of treatment is mandated.
Hexsyn Trileaflet Valve: Application to Temporary Blood Pumps
Authors: Kiraly Raymond , Yozu Ryohei , Hillegass Donald , Harasaki Hiroaki , Murabayashi Shun , Snow Jeffrey , Nosé Yukihiko
Published: November 2008

A trileaflet valve, compression molded of Hexsyn rubber, was evaluated as a component in temporary blood pumps. A pair of valves was integrated into an LVAD which was tested in vitro and in vivo. The valve's hemodynamic performance was satisfactory and the blood compatibility was excellent in a three‐week, in vivo experiment conducted to demonstrate performance in a short‐term application. Hexsyn, which has excellent properties and produces high quality, complex components with ease of fabrication, offers a potential for low‐cost blood pump valves.
Twin Calves, Total Artificial Heart, Cardiac Transplantation
Authors: Olsen Don B. , Gaykowski Rick , Blaylock Robert C. , Finch Lowana , Kolff Willem J.
Published: November 2008

Summary: Numerous laboratories throughout the world are successful in sustaining life in calves, sheep, and goats implanted with total artificial hearts for 4–8 months. Very good reliability has been demonstrated with some of these devices, and all of the more successful devices are pneumatically driven. These pneumatic controllers are, for the most part, large and nonportable, and thus are criticized when considered for permanent tethering to a human recipient. The artificial hearts, however, have been developed to a stage where they could sustain the circulation for indeterminate periods of time, for 2–3 years. The pneumatic total artificial heart was used for a few weeks in calves, and then followed with cardiac transplantation. This format has been suggested for human application.
Improvement in Intra‐aortic Balloon Pumping and Evaluation of Its Efficacy by Electrode Methods of Control
Authors: Ioseliani Georgiy D. , Chilaia Sergei M.
Published: November 2008

Summary: A basically new design for the reversing balloon pump has been proposed for increasing the efficacy of intra‐aortic balloon pumping (IABP). The device not only causes a significant increase in discharge, but also permits control of the central and peripheral circulation within the desired limits owing to back‐and‐forth movements (like a piston) of the balloon pump. Standard one‐and two‐chamber balloon pumps were compared. In addition to traditional hemodynamic and biochemical indexes, the efficacy of IABP was assessed based on electrode monitor control of Po2 and pH in the myocardium, peripheral tissues, and circulating blood. Based on 54 experiments on dogs, it was found that IABP with reversing balloon pumps in synchronous pulsation resulted in survival of 69% of the cases; Po2 and pH levels in the myocardium, tissues, and blood in the coronary sinus were close to normal, and coronary blood flow and peripheral circulation were increased. With standard one‐chamber balloon pumps, the survival rate did not exceed 33.4%; Po2 and pH in the peripheral tissues reached critical levels.
Development of Methods of Assisted Circulation with Artificial Heart Ventricles
Authors: Tolpekin Vladimir E. , Ioseliani Georgiy D. , Drobyshev Viktor A. , Makhatadze Teymuraz M.
Published: November 2008

Summary: A comparative study of two methods of bypassing the heart with artificial ventricles (AV) was conducted: left atrium‐aorta and left ventricle‐aorta. The following factors permit left ventricular bypass to compete successfully with left ventricle‐aorta bypass: creation of perfected pumps with low input impedance, use of materials with high resistance to thrombus formation for preparation of the AV and main connecting lines, and development of optimum methods of anticoagulant, disaggregation, and cardiac therapy so that there is no danger of thrombosis and hemorrhage, either experimentally or clinically. Thrombosis was the primary cause of death in only one case in a series of experiments on 15 calves with AV connected according to the atrium‐aorta scheme. The positive changes in hemodynamics were approximately the same with the two methods.
Cardiovascular Pathology in Dialysis Patients with Spinal Cord Injury
Authors: Pahl M. V. , Vaziri N. D. , Gordon S. , Tuero S.
Published: November 2008

Abstract: Necropsy findings were examined in 20 male patients with end‐stage renal disease associated with longstanding spinal cord injury and treated with maintenance hemodialysis. All patients exhibited cardiovascular abnormalities. Fibrinous pericarditis was found in 50% of the patients. Left and right ventricular hypertrophy was present in 45% and 20% of the cases, respectively. The respective incidences of left and right ventricular dilatation were 40% and 30%. Cardiac amyloidosis was noted in 25% of the cases, whereas myocardial fibrosis was found in 45% of the patients. Valvular abnormalities were limited to one case of aortic stenosis and two cases of mitral ring dilatation. No evidence of infective endocarditis was observed despite the high incidence of infections in this population. Whereas 45% of the patients exhibited some degree of coronary arteriosclerosis, none exhibited evidence of acute myocardial infarction and only one showed pathologic changes consistent with old myocardial infarction. Aortic atherosclerosis was noted in the majority of patients.
Characterization of Polypropylene Membrane for Plasma Separation
Authors: Sato Hiroshi , Malchesky Paul S. , Nosé Yukihiko
Published: November 2008

Abstract: Plasma separators of two different types constructed with polypropylene membrane were evaluated. Characterization of the membrane indicated that these separators meet the desired clinical requirements for sieving, filtration, and blood compatibility. In vitro sieving coefficients for albumin and total protein were 0.97 and 0.90, respectively. These modules showed a filtration flux dependency on blood shear rate. The ET filter (0.2 m2) had a higher shear rate for a given blood flow and also a higher flux. Based on the anticipated clinical applications at lower blood flows (<100 ml/min), small surface area devices having high shear rates meet clinical needs. The higher surface area module (Plasmaflux) also gave a satisfactory performance.
Complement Metabolism During Membrane Plasma Separation
Authors: McLeod Bruce C. , Viernes Ann , Sassetti Richard J.
Published: November 2008

Abstract: Because it has been found that some plasma separator membranes can activate complement in serum, this study focuses on the behavior of complement during actual membrane plasmapheresis. Complement metabolism in subjects undergoing membrane plasma separation with three different prototypic devices was studied. Complement activation was judged by crossed immunoelectrophoretic analysis of C3 in plasma. A cellulose acetate separator employed with heparin as the anticoagulant caused extensive C3 conversion (up to 50%) in separated plasma. A polysulfone separator used with citrate, and a polyvinylchloride derivative separator employed with heparin plus citrate, caused only small amounts of C3 conversion (0–10%) in separated plasma. C3 conversion in the cellulose acetate separator was reduced when citrate was included in the anticoagulant regimen, whereas C3 conversion in the polyvinylchloride derivative separator was increased when citrate was omitted. Activation of complement by the membrane material may occur during membrane plasma separation. Selection of membranes judged weakly activating by in vitro screening and the use of citrate anticoagulation would appear to minimize complement activation in membrane plasma separators.
In Vitro Fluid Dynamic Characteristics of Ionescu‐Shiley and Carpentier‐Edwards Tissue Bioprostheses
Authors: Yoganathan Ajit P. , Woo Yi‐Ren , Williams Frank P. , Stevenson Dana M. , Franch Robert H. , Harrison Earl C.
Published: November 2008

Abstract: In the study Reported here, the in vitro fluid dynamic characteristics of the Ionescu‐Shiley (calf pericardial) and Carpentier‐Edwards (porcine) aortic tissue valves were studied. The experiments conducted were pressure drop measurements, leaflet photography, flow visualization, and velocity measurements. The pressure drop studies indicated that both types of tissue valves created relatively large pressure drops. These pressure drops were larger than those observed with the corresponding sizes of Bjork‐Shiley, Hall‐Kaster, and St. Jude aortic prostheses. The photographs of the opening of the valve leaflets indicated that the tissue valves do not open as ideally as do the natural valves. It was also observed that the Ionescu‐Shiley aortic valves opened more symmetrically and with reproducibility than the corresponding Carpentier‐Edwards aortic valves. Velocity and shear stress measurements made with a laser‐Doppler anemometer indicated that the flow that emerged from the leaflets for both types of tissue valves was like a jet and could lead to turbulent shear stress on the order of 1,000–3,000 dynes/cm2. Such turbulent shear stresses could be harmful to blood components. The jet‐type flow could also damage the endothelial lining of the wall of the ascending aorta. The velocity measurements also indicated an annular region of stagnant fluid between the outflow surfaces of the leaflets and the flow channel wall. Such a region could lead to the build‐up of thrombotic, fibrotic, and/or calcific material on the outflow surfaces of the leaflets. Both types of valve designs, however, created relatively low wall shear stresses and regurgitant volumes.
Surgical Use of Fluosol‐DA in Jehovah's Witness Patients
Authors: Ohyanagi Harumasa , Nakaya Seishi , Okumura Shuichi , Saitoh Yoichi
Published: November 2008

Abstract: The effects of Fluosol‐DA 20% on circulating blood cells, hemodynamic parameters, blood gases, and organs are described and compared with the results of phase I human studies and animal experiments. Because of preoperative anemia and/or surgical bleeding, Fluosol‐DA 20% was administered to 7 of 10 Jehovah's Witness patients treated in this hospital. Six received 1,000 ml and the seventh received 2,000 ml. Hematological changes were examined after the administration of a 1‐ml test dose and at early and late stages of Fluosol‐DA 20% administration. Hemodynamics and blood gases were measured before and after infusion of Fluosol‐DA 20%. Hepatic function was also determined. A drop in neutrophils and platelets was observed in some patients after the injection of a 1‐ml test dose. This transient reaction was of short term, and the neutrophil and platelet levels recovered spontaneously. Both the efficacy and the safety of Fluosol‐DA 20% were demonstrated in these patients.

Summary: Because of preoperative anemia and/or moderate surgical bleeding, Fluosol‐DA 20% was administered to seven Jehovah's Witness patients: six with a dose of 1,000 ml each and one with a dose of 2,000 ml.

A transient drop in neutrophils and platelets was observed in four patients after the injection of a 1‐ml test dose of Fluosol‐DA 20%. However, pretreatment with drugs seemed to be dispensable because this initial reaction was transient and reversible.

The efficacy and safety of Fluosol‐DA were demonstrated in these patients when the fractional concentration of the oxygen in inspired gas was ˜0.5 or 0.6.

Intravenous administration of Fluosol‐DA 20% (up to 30 ml/kg) to hemorrhagic patients supported the hypothesis that Fluosol‐DA 20% can be used clinically as a blood gas carrier, in emergency situations, without any untoward reactions.
Effect of Plasma Proteins on the Sieving Spectra of Hemofilters
Authors: Feldhoff Pamela , Turnham Timothy , Klein Elias
Published: November 2008

Abstract: A mixture of neutral maltodextrins with a continuous molecular weight distribution from 340 to 120,000 daltons has been used alone or in the presence of plasma to determine solute rejection by four hemofilters and the effect of plasma on such rejection. High pressure liquid chromatographic analyses were utilized to establish concentration ratios of feed and filtrate solutions over a wide molecular weight range. At equal transmembrane velocities, the boundary layer‐corrected rejection of each hemofilter was determined as a function of molecular weight. The presence of plasma increased rejection by the Amicon Diafilter 30, the Hospal RP‐6, and he Gambro FH202 hemofilters, but the Fresenius D‐6 was virtually unaffected.
Comparison of Chemical Analyses of Hollow‐Fiber Dialyzer Extracts
Authors: Pearson Frederick C. , Bohon Joyce , Lee Wanda , Bruszer George , Sagona Mike , Dawe Robin , Jakubowski George , Morrison David , Dinarello Charles
Published: November 2008

Abstract: Hollow‐fiber hemodialyzers containing cellulose‐based membranes have been shown to produce positive results with the Limulus amebocyte lysate (LAL) test. This study was undertaken to determine whether endotoxin was causing the reaction. Rinses from 45 parallel‐plate and hollow‐fiber dialyzers from eight different manufacturers were tested using three lysates and four LAL methods. In addition, four in vitro cellular methods‐human leukocytic pyrogen, lymphocytic activating factor, peritoneal macrophage, and arginase release‐were used to evaluate endotoxin activity. The substance causing the reaction was identified using chromatographic methods. Results indicate that the LAL‐reactive material is cellulose derived and is not pyro‐genic.
Residual Ethylene Oxide in Hollow‐Fiber Dialyzers
Authors: Henne Werner , Dietrich W. , Pelger Michael , von Sengbusch Giünter
Published: November 2008

Abstract: The deaeration and extraction kinetics of ethylene oxide (ETO) in hollow‐fiber dialyzers were examined. The investigations showed that both deaeration and extraction can be described by two additive first‐order kinetic expressions. The ETO content of membranes decreased rapidly at first, followed by a second slower decrease. Even after prolonged storage time, residual ETO was still detectable in the milligram range. These residuals cannot be eliminated by the usual rinsing of the di‐alyzer prior to use.
Role of Dialyzer Contaminants in the Allergic Epiphenomena of Hemodialysis
Authors: Ward Richard A. , Feldhoff Pamela W. , Klein Elias
Published: November 2008

Abstract: Cuprophan hollow‐fiber dialyzers contain contaminants including 1,2,3‐propanetriol, carbohydrates, Limulus amebocyte lysate‐reactive material, and particulates. In a clinical study, the role of these substances in the allergic‐type response seen in some hemodialysis patients was examined. Patients were dialyzed three times per week for 6‐week intervals with each of four dialyzer preparations designed to vary the burden of contaminants presented to the patient. Predialysis eosinophil counts and serum immunoglobulin (Ig) E levels were obtained weekly. White cell and platelet counts and plasma C3a and C5a levels were measured during dialysis for each dialyzer preparation. Dialyzer preparation had no effect on predialysis eosinophil counts or IgE levels. All patients demonstrated transient leukopenia and complement activation during dialysis, the magnitudes of which were unaffected by the type of dialyzer preparation. At the levels found in the dialyzers studied, it was questioned whether water‐soluble extractables or particulates play any role in the allergic epiphenomena of hemodialysis.
Long‐Term Observation of Retinal Electrical Activity in Dialyzed and Renal Transplantation Patients
Authors: Svêrák Jaromir , Peregrin Jaroslav , Hejcmanová Dagmar , Erben Josef
Published: November 2008

Abstract: The electroretinographic (ERG) intensity‐response function was evaluated in 90 patients subjected to regular dialysis treatment (RDT) and in 27 patients after renal transplantation. Using a logistic equation, three parameters for each set of ERG curves were computed: M, the retinal sensitivity; S, the slope; and A, the maximum attainable potential amplitude. A statistically significant decrease of the A and S values of both the b and a waves in the course of RDT was found. After ˜6 years of RDT, the frequency of patients with pathological A and S values amounted to 94.6% (b wave) and 80.4% (a wave). On the other hand, renal transplantation was accompanied by a tendency to normalize the original pathological values of the ERG parameters. Changes of electrical retinal activity could contribute to the evaluation of the state of compensation in dialyzed patients.
Migration of Acetylated Hemicellulose from Capillary Hemodialyzer to Blood, Causing Scleritis and/or Iritis
Authors: Oba Takuma , Tsuji Kusuo , Nakamura Akitada , Shintani Hideharu , Mizumachi Shogo , Kikuchi Hiroshi , Kaniwa Masa‐aki , Kojima Shigeo , Kanohta Kenzo , Kawasaki Yasushi , Furuya Tsuyoshi , Matsumoto Kiyoshi , Tobe Masuo
Published: November 2008

Abstract:From November 1981 to early March 1982, an outbreak of scleritis and/or iritis occurred among patients treated with a Nipro brand NAC series cellulose acetate capillary dialyzer. The rate of incidence with dialyzers produced in 1982 was significantly higher than that with dialyzers produced in 1981. An extract obtained from the dialyzers caused iritis in rabbits after its infusion into an auricula vein. Glycerol, acetylated carbohydrate (AC) derivatives, urethane derivatives, and polypropyleneglycol were found in the extract. AC derivatives caused iritis in rabbits, whereas they caused hyperemia of the bulbar conjunctiva in dogs. The AC derivatives contained xylose and glucose units in a ratio of 1.6‐2.3: 1. The amounts of AC derivatives were significantly larger in the extracts from 1982 than from 1981 devices. Moreover, another brand, but the same type, of dialyzer, the Cordis Dow 4000, contained a slight amount of them. These facts show that AC derivatives derived from hemicellulose played a primary role in the outbreak.
New Sequential External Counterpulsation for the Treatment of Acute Myocardial Infarction
Authors: Zheng Zhen‐sheng , Yu Li‐qun , Cai Shu‐rui , Kambic Helen , Li Tian‐mu , Ma Hong , Chen Pu‐zhao , Huang Bao‐jun , Nosé Yukihiko
Published: November 2008

Abstract: Over a period of 6 years, 52 patients with acute myocardial infarction (AMI) were treated with sequenced external counterpulsation (SECP). Of the 23 patients who experienced severe chest pain, 22 had complete relief within 30 min of SECP, and 31 of the 52 patients showed remarkable improvement in their electrocardiogram after the first hour of treatment. Fifteen patients were studied using the 35‐lead ST segment elevation‐mapping method.σST and NST, indicators of infarct size, showed decreasing trends in seven patients treated with SECP for a period of 6 days, whereas σST and NST of the control group of eight patients increased during the same period. Our hemodynamic data indicate that in four of five patients with AMI and left heart failure, the central venous pressure and cardiac output increased after SECP, whereas the pulmonary wedge pressure decreased. Measurements of the P‐wave terminal force of lead V1 also demonstrated that the application of SECP can improve left ventricular function in a majority of patients with AMI.
Differences in the Effect of Hemodialysis on the Residual Clearance of Inulin, Endogenous Creatinine, and Urea
Authors: Teplan V. , Schück O. , Nddvorníková H.
Published: November 2008

Abstract: In a group of 20 patients on regular hemodialysis treatment (HD), the residual glomerular filtration rate was examined before and 12 h after the end of HD. Inulin clearance decreased significantly after HD (p<0.001), whereas endogenous creatinine and urea clearance did not change. The results suggest that HD influences the function of residual nephrons.