bluuebunny/crossref_metadata_2025 huggingface dataset:
Long‐Term Ventricular Wall Actuation: Can and Should It Be Systematically Explored?
Authors: Melvin David B. , Schima Heinz , Losert Udo M. , Wolner Ernst
Published: November 2008

Abstract: Hearts fail because myocardial power fails. Assist, support, or replacement devices fail, at least in part, because their blood‐contacting surfaces fail. Mechanical repowering of a failing heart might circumvent these difficulties by preserving a largely healthy endocardium while correcting the basic deficit, power. Any serious consideration of doing this though must confront some difficult requirements. Effective indefinite support must be coupled with preservation or restoration of valve competence, coronary flow, rapid low‐impedance refilling and independent left and right pressures; the avoidance of wall coaptation; hardware that fits in the available space; and unless muscle powered, adaptability to a deliverable form of power. Despite earlier intense interest in acute mechanical devices and later empiric study of muscle wraps, little systematic methodical work has been done on elucidating and meeting these practical requirements. Concerted efforts toward developing research tools and techniques for their study and then finding mechanisms to meet them could well yield one or more effective modalities that circumvent a major obstacle to the indefinite mechanical treatment of heart failure
Effect of Simulated Valvular Stenoticity on Predicted Flow Area for a Bileaflet Valve Using the Gorlin Equation
Authors: Souza‐Campos Flavio , Del‐Boca Adrian , Schoephoerster Richard T.
Published: November 2008

Abstract: The possibility that the discharge coefficient (Cd) for a mechanical heart valve (MHV) is affected by valvular stenosis is addressed. A 29 mm bileaflet (St. Jude Medical) mitral valve is tested on a cardiovascular duplicator (CVD) in its normal state and under two degrees of simulated stenosis. Stenoticity is simulated by bracing the occluders such that full opening is impossible. The pressure drop through the valve is described by a two‐term second‐order polynomial in flow, from which it is shown that the Q should be a nonlinear function of the flow rate through the valve. The average difference between measured and calculated areas decreased from 74%, when a constant value of 0.7 was used for the Cd, to 3.7%, when the Cd was a nonlinear function of the flow rate.
Modification of a Pivot Bearing System on a Compact Centrifugal Pump
Authors: Nakazawa Tadashi , Makinouchi Kenzo , Takami Yoshiyuki , Glueck Julie , Takatani Setsuo , Nosé Yukihiko
Published: November 2008

Abstract: The pivot bearing centrifugal blood pump was developed as a long‐term centrifugal ventricular assist device (VAD) as well as a cardiopulmonary bypass pump. This pivot bearing supported centrifugal pump with an eccentric port (C1E) incorporates a seal‐less design with a blood stagnation‐free structure. This pump can provide flows of 12 L/min against 650 mm Hg total pressure head at 3,600 rpm, and in a CPB condition 5 L/min against 350 mm Hg total pressure head at 2,600 rpm. Very recently, the pivot bearing system was modified to obtain a stable and smooth spinning movement. The material of the female pivot was changed from ceramic to polyethylene. Three kinds of bearings were tested simultaneously with bovine blood in two types of in vitro circuits to determine the blood damage from the bearings. Pressure differences across the pump (total head pressure, A/1) of 140 mm Hg (n = 12) and 330 mm Hg (n = 12) were examined. The normalized index of hemolysis (NIH) was slightly higher in a ball bearing (BB) pump than in a polyethylene bearing (PB) pump and statistically higher than the BioMedicus Pump (BP‐80) on ΔP of 140 mm Hg. When the ΔP was at 330 mm Hg, a comparison between the three types of pumps revealed no difference in NIH. In addition, the primary vane of the impeller was redesigned to obtain an atraumatic structure. In the second study (n = 14), there was no difference in the NIH between BP‐80 and the current model when the A/5 was 300 mm Hg (0.019 ± 0.002 vs. 0.027 ± 0.006, p = 0.3) and/or when the A/1 was 100 mm Hg (0.0008 ± 0.0001 vs. 0.0014 ± 0.0002, p = 0.07). The modified pivot bearing had an improved spinning condition and no change in hemolysis. A proper selection of pivot bearing materials is important to develop an atraumatic centrifugal pump. The modification of the bearing system and redesign of the vane enabled a compact centrifugal pump to become a reality.
Low–Density Lipoprotein Apheresis Versus Lipid Lowering Drugs in the Treatment of Severe Hypercholesterolemia: Four Years' Experience
Authors: Schiel Ralf , Bambauer Rolf , Miiller Ulrich
Published: November 2008

Abstract: Elevated lipoprotein concentrations seem to be linked strongly in a dose dependent manner to an increased incidence of atherosclerosis. A total of 47 patients suffering from severe hyperlipidemia were matched to treatment with LDL apheresis (Baxter, Kaneka, Li–popak; 24 patients, aged 50.2 ±11.5 years), diet, and/or lipid–lowering drugs or with diet and lipid–lowering drugs only (23 patients, aged 48.8 ±11.8 years). After treatment periods of 49.8 ±13.4 months (apheresis group, 2,396 treatment sessions) and 38.6 ±15.1 months (drug group), the ensuing results revealed significant differences (p <0.0001): –47.3% versus –12.1% for total cholesterol, –46.9% versus –21.8% for LDL, +8.4% versus +0.9% for HDL, –52.0% versus – 13.1% for the LDL/HDL ratio, –36.4% versus –16.2% for triglycerides, and –25.9% versus + 1.5% for lipoprotein (a). In the apheresis group, one patient died of myocardial infarction; in the drug group, there was one nonfatal myocardial infarction and the manifestation of coronary heart disease in 3 cases. There were no severe side effects in either group. All patients in the apheresis group responded to therapy. The present trial suggests that a continuing reduction in serum lipid concentrations may lower, in a dose dependent manner, the risk for development and progression of coronary heart disease. Regarding clinical and laboratory results, LDL apheresis seems to be safe, effective therapy for treatment of severe hyperlipidemia.
Low–Density Lipoprotein Adsorption for Arteriosclerotic Patients
Authors: Sato Y. , Agishi T.
Published: November 2008

Abstract: A wide variety of treatments is now available for arteriosclerosis obliterans (ASO) patients, not very successful in some cases. Low—density lipoprotein (LDL) apheresis using an extracorporeal adsorption column containing dextran sulfate cellulose beads was applied to control lipid levels intensively in ASO patients with accompanying drug—resistant hyperlipidemia. A series of the apheresis procedures had a remarkable impact on clinical symptoms and physiological findings with improvement in intermittent claudication observed in more than 80% of the patients. Improvements in plethysmogram and thermogram readings suggested an increased circulation in lower extremities in more than 80% of patients. In addition, the treatment improved blood rheology, as evidenced by a reduction in blood viscosity. In a follow—up study made by sending a questionnaire to previously treated patients, it was revealed that improvements in clinical symptoms were well maintained even after cessation of the treatment. In conclusion, LDL apheresis proved to be a useful therapeutic tool in ASO patients having elevated lipid levels
The Cleveland Clinic Rotodynamic Pump Program
Authors: Golding Leonard A.R. , Smith William A. , Bodmann Douglas R.
Published: November 2008

Abstract The Cleveland Clinic Foundation has developed a unique rotodynamic blood pump for future use as a permanent implant. This pump is small (2.5 ± 2.5 inches) and requires an electric input power of 7 watts to produce 5 L/min of blood flow against 100 mm Hg at 3,000 rpm. Initial in vivo testing has confirmed in vitro function and shown low hemolysis. Endurance bench testing has exceeded 12 months of continuous function. This pump is the basis of an innovative ventricular assist system in which power is supplied by a tranocutaneous electrical transmission system, and pacer technology is used for both control logic and telemetry functions. The resulting system will be completed and tested under an NHLBI contract during the next 5 years.
Comparison of Centrifugal and Roller Pump Hemolysis Rates at Low Flow
Authors: Moon Yuko S. , Ohtsubo Satoshi , Gomez Michael R. , Moon Jon K. , Nose Yukihiko
Published: November 2008

Abstract We compared in vitro rates of hemolysis for a recently developed centrifugal pump with a conventional roller pump (10‐10‐00; Stöckert, Munich, Germany). Flow rates of 0.3 L/min and 1 L/min and a pressure of 200 mm Hg were chosen to simulate conditions during neonatal extracorporeal membrane oxygenation (ECMO). There was no significant difference in hemolysis rates between centrifugal and roller pumps (p = 0.57) nor between high and low flow (p = 0.86). The centrifugal pump caused no more blood trauma than the roller pump at the low‐flow/high‐pressure conditions required for neonatal ECMO. The Nikkiso pump is superior to roller pumps in size and priming volume (25 ml) and may permit development of a smaller and simpler ECMO system.
A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential
Authors: Dame Don
Published: November 2008

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to “slip around” the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating “swinging” hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not “rotate”; therefore, no rotating shaft seal or internal bearings are required.
Hemodynamic System Analysis of Intraarterial Microaxial Pumps In Vitro and In Vivo
Authors: Siess Thorsten , Meyns Bart , Spielvogel Klaus , Reul Helmut , Rau Günter , Flameng Willem
Published: November 2008

Abstract: Because of the lack of a sophisticated pump management system, the performance of the Hemopump in patients cannot be assessed successfully. To clarify the interrelationship between an intravascular nonpulsatile pump and a pulsating ventricle, an in vitro study was set up under controlled conditions. Before these in vitro experiments, a series of in vivo experiments were performed in sheep using Hp31 cannulae. As anticipated, the resulting pulsatile pump flow was a function of the momentary pressure difference across the pump. This varying pump flow showed a significant flow loop hysteresis, indicating that the pressure difference across the pump is not the only parameter governing momentary pump flow of a rotary pump operating at constant speed in a pulsatile environment. Furthermore, flow in the Hp31 was significantly influenced by the inflow situation, blood supply, size of the ventricular cavity, and shape and position of the inflow cannula within the ventricle. Pulsatile flow conditions with good as well as impaired inflow into the pump were accordingly simulated in vitro to verify the in vivo measurements, to characterize the various inflow conditions, and to discuss methods of improved pump management. As a result of the in vivo and in vitro experiments, one can rely on the measurement of nonpulsatile in vitro flow and pressure differences across the pump to characterize the momentary pump flow for good inflow conditions into the pump. For these situations, the flow hysteresis produced, caused by fluid inertia within the pump and cannula, can be neglected. In contrast, for an impaired inflow situation, the calculated pump flow based on pressure difference measurements can be misleading. Consequently, an improved pump management system is required to adjust the pump speed, the pump performance, to any kind of impaired inflow.
Pharmacologically Induced Heart Failure for the Evaluation of Circulatory Assistance
Authors: Schmidt C. , Schwendenwein I. , Wieselthaler G. , Roschal K. , Schima H. , Losert U. , Wolner E.
Published: November 2008

Abstract: For the evaluation of the hemodynamic interaction between the natural heart and an assist device, a reversible pharmacological model based on the channel blocker Verapamil under hyperkalemia, was developed for deterioration of left ventricular function. Four calves weighing 70–90 kg underwent standard implantation for left atrioaortal assist (BioMedicus, BP‐80), pump anesthesia (oxygen/isoflurane [1%]; 8 mg/kg of BW/h keta‐mine), and of ventricular demand pacing at 120 bpm. Left atrial pressure (LAP), ventricular pressure (LVP), aortic pressure (AoP), pulmonary arterial (Qpulm) pressures, and graft flow (Qgraft) were monitored. The hemodynamic effects of anesthetic overdose (2% Isoflurane) were compared with those of Verapamil (Isoptin: 0.2 mg/kg BW/h 5 mmol/kg of BW/h of KC1) medication. Both regimens caused a decrease in AoP to ≤50%. For Isoflurane, a slight reduction in cardiac output (CO) of 10% at a nearly constant LAP and a strong decrease of the peripheral resistance (Rperi) of 35% could be seen where Isoptin caused a significant reduction in CO of 40% at an increased LAP (+ 25%) and changes in Rperi of <10%. Because the vascular tonus remains nearly constant, the hemodynamic effects are controllable and reversible (antagonized with calcium chloride); thus we conclude that Verapamil administration under hyperkalemia conditions is a proper model for mimicking congestive heart failure with low systemic side effects.
Role of the BioMedicus Pump and Distal Aortic Perfusion in Thoracoabdominal Aortic Aneurysm Repair
Authors: Safi Hazim J.
Published: November 2008

Abstract: We reviewed the role of the BioMedicus pump in the reduction of neurologic complications following the repair of Type 1 and Type 2 thoracoabdominal aortic aneurysms. Since 1991, we have used several different methods for the repair of thoracoabdominal aortic aneurysms including simple cross‐clamping, selective use of the BioMedicus pump, cardiopulmonary bypass with or without profound hypothermia, and most recently, distal aortic perfusion using the BioMedicus pump combined with cerebral spinal fluid drainage. This latter method has been the most promising in rectifying the side effects of aortic clamping and in providing the time necessary for thorough thoracoabdominal aortic aneurysm repair. On our service, the ongoing study of the BioMedicus pump and distal aortic perfusion in conjunction with cerebral spinal fluid drainage has shown that these adjuncts can extend the tolerance of the spinal cord to ischemia and lower the overall rate of neurologic complications for Type 1 and Type 2 thoracoabdominal aortic aneurysm repairs to a rate of 5% (early results) and 3% (late results). We highly recommend distal aortic perfusion using the BioMedicus pump combined with cerebral spinal fluid drainage for thoracoabdominal aortic aneurysm repair.
A New Supportive Method for Aortic Aneurysm Surgery: Centrifugal Left Heart Bypass Combined with an Oxygenator and a Heat Exchanger
Authors: Aomi Shigeyuki , Hashimoto Akimasa , Tagusari Osamu , Nishida Hiroshi , Nomura Minoru , Kondoh Izumi , Kodaka Keiko , Koyanagi Hitoshi
Published: November 2008

Abstract: A new supportive method of centrifugal left heart bypass with oxygenation was performed in 25 patients and compared with standard left heart bypass in 45 patients. Femoro‐femoral bypass was selected in another 6 patients because of the presence of a left atrial adhesion. Intraoperative complications related to standard left heart bypass, hypoxia, hypothermia, and ventricular fibrillation, were eliminated by using this method. This supportive method maintained good hemodynamics and improved the surgical result of extended thoracoabdominal aortic replacement. Hospital deaths decreased from 6.7% to 3.2%.
Clinical Experience of Percutaneous Cardiopulmonary Support
Authors: Sasako Yoshikado , Nakatani Takeshi , Nonogi Hiroshi , Miyazaki Shunichi , Kito Yoshitugu , Takano Hisateru , Kawashima Yasunaru
Published: November 2008

Abstract: Recently, percutaneous cardiopulmonary support (PCPS) combined with femoro‐femoral bypass without reservoir has become valued because of its quick and easy application. We developed a fully preconnected compact integrated cardiopulmonary bypass (CPB) unit (priming volume of 250 ml) with a blind pore membrane oxygenator (Kuraray Menox) for PCPS. From 1990 to 1995, PCPS was performed in 49 patients of whom 26 were weaned from support. In most cases, we applied this CICU in patients with no active bleeding (22 patients); in patients with active bleeding (n = 13), we used Medtron‐ic's heparin‐bonded close chest support pack (CCSP). Of these, PCPS was performed uneventfully for 2 h (median) in 8 elective cases; all of these patients were weaned or were switched to a left ventricular assist system (LVAS). In 8 urgent cases, such as those with low cardiac output syndrome, PCPS was performed for 4 days (median), 1 was weaned, and 2 CICU were cases switched to other procedures. In 32 cases of shock, 5 CICU patients were weaned, and 3 of them survived. Eight patients including 5 CICU patients and 1 CCSP patient were switched to operation or LVAS, and 2 CICU patients remain alive. From these data, PCPS has been shown to support the patient's circulation in the acute phase and earn time to switch to operation or LVAS; the quick and easy set‐up of the CICU can improve the clinical results. The use of the Medtronic device broadened the indication for PCPS. The CCSP enlarged the indication of PCPS but could not improve the results. To improve the results, a heparin‐bonded surface is desired.
Experimental Glomerulosclerosis: Defektheilung of the Kidney
Authors: Schiller Brigitte , Moran John
Published: November 2008

Abstract Research in the role of cytokines in experimental glomerulonephritis has increased our understanding of the mechanisms that may be involved in the development of progressive renal disease. Glomerulosclerosis, the final common pathway in a variety of underlying kidney diseases, is characterized by increased extracellular matrix formation and cell proliferation. Transforming growth factor‐β (TGF‐β) and monocyte chemoattractant protein‐1 (MCP‐1) have been identified in animal models as mediators in the processes that follow renal injury. There is evidence of similar events occurring in other fibrotic disorders, suggesting that there is a common generic pathway of fibrosis. This review summarizes our knowledge of TGF‐β and MCP‐1 in experimental kidney disease and compares these results with mechanisms described in other organs. We propose that glomerulosclerosis represents Defektheilung (healing by secondary intention) of the kidney after various injuries. The growing knowledge of the mechanisms involved will help advance future therapeutic interventions by directing the healing process toward primary healing.
Hanta Is Coming
Authors: Schreiner George E.
Published: November 2008

Abstract The Hanta virus is coming again. Yes, it is coming again and again t o your town to your rodents and to your homes! We can resolve to prevent it, contain it, and treat it in a scientific and humane way, or we can salivate, scratch, bite, and run like rats and mice and voles and shrews.
Effectiveness and Limitations of the Fallback I Algorithm for Transient Supraventricular Tachyarrhythmias in DDD Pacing
Authors: Mayumi Hisanori , Matsuzaki Kouji , Kohno Hiroyuki , Matsui Kanzi , Kawachi Yoshito , Yasui Hisataka
Published: November 2008

Abstract: To examine the function of the Fallback I algorithm (Chorus I, Ela Medical Inc., Montrouge, France), which automatically changes the DDD mode to VDI during transient supraventricular tachyarrhythmias to prevent high‐rate tracking of the ventricle, a total of 45 patients who were preoperatively diagnosed with sick‐sinus syndrome (SSS) (Group 1; n = 19) or with advanced or complete atrioventricular block (AVB) (Group 2; n = 26) were followed up and analyzed. Mean follow‐up times (mean ± SD) were 22.4 ± 9.7 and 12.4 ± 10.9 months, respectively. Each of the groups was further divided into subgroups according to the preoperative existence of paroxysmal atrial fibrillation (or flutter) (PAF) or paroxysmal supraventricular tachyarrhythmia (PSVT). During follow up, the fallback started through a given cycle of ventricular pacing at an upper‐rate limit (URL) to avoid a continuous high‐rate tracking during the arrhythmias specifically in the patients with PAF (17/18), but it did not start in the patients with PSVT (0/4) (p = 0.0004). The fallback, however, sometimes started in the patients who had AVB not associated with either PAF or PSVT (4/21) during normal exercise because the fallback algorithm did not distinguish a normal P wave from the abnormal atrial waves. To further clarify the behavior of the fallback, a treadmill test was conducted in 25 of the 45 patients. The fallback start was observed in 12 of the 17 patients with AVB (Group 2). In such patients, the use of a long fallback delay and/or a high URL setting prevented the fallback starts during normal exercise. These results suggest that, in DDD pacing, the fallback algorithm in Chorus I is useful in patients with SSS or AVB to avoid high‐rate tracking of the ventricle during transient supraventricular tachyarrhythmias, but special care must be taken to avoid the fallback starts during the normal exercise in AVB patients.
Interaction Between Cell‐Surface‐Expressed 70‐Kilodalton Heat Shock Protein‐like Antigen and CD3 + 4‐8‐ Killer T Cells
Authors: Takashima Satoru , Sato Noriyuki , Kishi Akihiko , Tamura Yasuaki , Sagae Satoru , Kudo Ryuichi , Torigoe Toshihiko , Yagihashi Atsuhito , Kikuchi Kokichi
Published: November 2008

Abstract: The 70‐kilodalton heat shock proteins may be expressed on the cell surface by an unknown mechanism and may interact with CD3 + 4‐8‐ T cell receptor‐αβ‐ killer (DNT) cells. In this interaction, certain cellular nascent or mutant peptides may be important (the complexes of 70‐kilodalton heat shock protein and cellular peptides directly interact with DNT cells). The results imply that the interaction between 70 kilodalton heat shock proteins and DNT cells may also work in graft rejection. By using antibodies that react with the cell surface‐expressed 70‐kilodalton heat shock proteins, one may overcome graft rejection. Key Words: Heat shock proteins–T cells–Cellular peptides–Molecular chaper‐ones.
Interleukin‐10 Inhibited the Expression of Tumor Antigens and Major Histocompatibility Complex Antigen on EJ‐ras Oncogene Transformants
Authors: Tsuruma Tetsuhiro , Yagihashi Atsuhito , Torigoe Toshihiko , Okada Yojiro , Sato Noriyuki , Kikuchi Kokichi , Hirata Koichi
Published: November 2008

Abstract: Interleukin‐10 (IL‐10), a novel inhibitory cytokine, is one of Th‐2 (T helper) cytokine. It inhibits mixed lymphocyte reaction, and the production of inflammatory cytokine and monokine downregulates major histocompatibility complex antigen (MHC) class II antigen expression. However, the effect of IL‐10 on tumor cells is not known. Therefore, the mechanism of tumor tolerance induced by IL‐10 was investigated. (WKA rat fetus‐derived fibroblast) (WFB) and W14 and W31 (EJ‐ras oncogene transformants of WFB) were cultured with recombinant human (rh)IL‐10 (0, 10, 50, 100 ng/ml). FACS analysis was performed using the following monoclonal antibodies: anti‐rat MHC class I monoclonal antibody; and monoclonal antibody 109 (anti‐natural killer [NK] target molecule on W14). Monoclonal antibody (mAb) 109‐defined antigens were newly expressed during the transforming process by EJ‐ras oncogene transfection to WFB. In addition, the effects of rhIL‐10 on the ability of proliferation and susceptibility to NK cells were assessed. The cultivation with rhIL‐10 resulted in a dose‐dependent decrease in the expressions of MHC class I antigen and monoclonal antibody 109‐defined antigen. The proliferation and susceptibility to NK cells of W14 were inhibited. These data demonstrated a possibility that IL‐10 could induce tumor tolerance to host immunity by inhibiting the expression of tumor‐associated antigens and MHC class I.
Optimal Control Algorithm for Pneumatic Ventricular Assist Devices: Its Application to Automatic Control and Monitoring of Ventricular Assist Devices
Authors: Arai Hirokuni , Fujiyoshi Kohji , Sakamoto Tohru , Suzuki Akio , Swartz Marc T.
Published: November 2008

Abstract We developed a control and monitoring unit for pneumatic ventricular assist devices (VADs), which provides optimal fill and empty control and real‐time evaluation of pump performance. The flow signal of the inflow cannula is integrated every beat to yield pump filling volume per pump diastole. The ejection signal is triggered when pump filling reaches a preset level. The instantaneous mean flow of each beat (stroke volume/cycle length) is compared with the previous beat, and the threshold level is readjusted to optimize flow. This feedback loop is repeated every beat, and pump filling is immediately adjusted to yield maximum pump flow. Simultaneously the mean flow of every 10 beats is compared with that of the previous 10 beats; then, the ejection time is readjusted to optimize flow. Initial clinical application of this unit supports its effectiveness and reliability.
Purge System for Rotary Blood Pumps
Authors: Sipin A.J. , Bender B. , Fabrey W.J. , Keller R. , Liu J. , Olsen D.B.
Published: November 2008

Abstract: Purge liquid has been supplied successfully to lubricate the bearings and wash the seals of rotary blood pumps to minimize hemolysis and thrombosis, extending their operating endurance. Although encouraging results have been obtained and development is proceeding for pumps with blood lubricated bearings, their validation and clinical use will occur some time in the future. For rotary blood pumps with purged bearings, a miniature purge liquid pump weighing 80 g has been successfully developed to meet the design point of 1 ml/h at 1,000 mm Hg (required by an existing rotary blood pump) with a motor power of 4 mW. The novel device maintains the flow rate for a sufficient time to service or replace the pump without flow interruption. A preliminary design has been made for a wearable purge delivery unit comprising a purge liquid pump, an electronic control, a purge liquid reservoir, and a battery.
Design Considerations for Bearingless Rotary Pumps
Authors: Kung Robert T.V. , Hart Robert M.
Published: November 2008

Abstract: The designs of rotary blood pumps have shown substantial technical progress over recent years, especially contact bearing designs. However, the concern for potential thromboembolism remains and can only be eliminated by the use of bearingless pumps. Bearingless designs can be achieved through the application of magnetic, hydro‐dynamic, and hydrostatic forces or a proper combination of these forces. Although a purely magnetically suspended, actively controlled system can be designed. judicious use of hydraulic forces can allow simplification of device configuration and control. In this study, bearingless designs were evaluated for both axial and centrifugal pump configurations. Trade‐offs between shear rates and bearing leak rates were considered based upon constraints imposed by hemolysis and residence time. These principles were used for determining the design feasibility of a rotary pump using combined magnetic and hydraulic stabilizing forces.
Noninvasive Pump Flow Estimation of a Centrifugal Blood Pump
Authors: Wakisaka Yoshinari , Okuzono Yasuki , Taenaka Yoshiyuki , Chikanari Kenichi , Masuzawa Toru , Nakatani Takeshi , Tatsumi Eisuke , Nishimura Takashi , Takewa Yoshiaki , Ohno Takashi , Takano Hisateru
Published: November 2008

Abstract: A flow rate estimating method was investigated for a centrifugal blood pump developed in our institute. The estimated flow rate was determined by the power consumption, the rotating speed of the motor, and the hematocrit value. The power consumption and the rotating speed of the motor were measured with a wattmeter. The examinations were performed in a closed mock loop filled with goat blood with hematocrit values of 21.5%. 28%, 34%, and 42%. Measured values of blood viscosity were 2.47, 3.09, 3.71, and 5.07 mPa. s at a share rate of 37.5/s, respectively. A linear correlation between the power consumption and the pump flow rate was observed in all hematocrit values. But variations in hematocrit caused a difference in the flow rate up to 1.1 L/min at the same power consumption and rotating speed. Effects of blood viscosity on the flow estimation were corrected by the hematocrit value. The value of the coefficient of determination, R2, between the estimated flow rate and the measured flow rate was 0.988. These results may indicate that the flow estimating method calculated by the power consumption of the motor, the rotating speed, and the hematocrit value is useful in the clinical situation.
Control of Centrifugal Blood Pump Based on the Motor Current
Authors: Iijima Tatsuhiko , Inamoto Taro , Nogawa Masamichi , Takatani Setsuo
Published: November 2008

Abstract: In this study, centrifugal pump performance was examined in a mock circulatory loop to derive an automatic pump rotational speed (rpm) control method. The pivot bearing supported sealless centrifugal pump was placed in the left ventricular apex to aorta bypass mode. The pneumatic pulsatile ventricle was used to simulate the natural ventricle. To simulate the suction effect in the ventricle, a collapsible rubber tube was placed in the inflow port of the centrifugal pump in series with the apex of the simulated ventricle. Experimentally, the centrifugal pump speed (rpm) was gradually increased to simulate the suction effect. The pump flow through the centrifugal pump measured by an electromagnetic flowmeter, the aortic pressure, and the motor current were continuously digitized at 100 Hz and stored in a personal computer. The analysis of the cross‐spectral density between the pump flow and motor current waveforms revealed that 2 waveforms were highly correlated at the frequency range between 0 and 4 Hz, with the coherence and phase angles being close to 1.0 and 0 degrees, respectively. The fast Fourier transform analysis of the motor current indicated that the second harmonic component of the motor current power density increased with the occurrence of the suction effect in the circuit. The ratio of the fundamental to the second harmonic component decreased less than 1.3 as the scction effect developed in the circuit. It is possible to detect and prevent the suction effect of the centrifugal blood pump in the natural ventricle through analysis of the motor current waveform.
Development of the Undulation Pump Total Artificial Heart
Authors: Abe Yusuke , Chinzei Tsuneo , Isoyama Takashi , Ono Toshiya , Mochizuki Shuichi , Mabuchi Kunihiko , Baba Kazunori , Matsuura Hiroyuki , Sun Yan Pin , Kouno Akimasa , Atsumi Kazuhiko , Fujimasa Iwao , Imachi Kou
Published: November 2008

Abstract: The undulation pump is a small size continuous flow displacement type blood pump that has been developed for an artificial heart. Using undulation pumps. 2 types of implantable total artificial hearts (TAHs), the undulation pump TAH (UPTAH) type 1 (UPTAH 1) and UPTAH type 2 (UPTAH 2) were developed. Both UP‐TAHs were designed to be small enough to implant into the chest of a goat, the experimental animal. UPTAH 1 could be reduced in size to 75 mm in diameter and 78 mm in length. The weight was 520 g. UPTAH 2 could be reduced in size to 75 mm in diameter and 80 mm in length. The weight was 650 g. UPTAH 2 could be tested in an animal experiment using an adult female goat weighing 52.3 kg. The UPTAH 2 could be implanted successfully into the goat's chest with a good fit. The goat stood after the surgery and extubation and survived for 3 h and 40 min; thus, the potential of the UPTAH for a practical implantable TAH was demonstrated.
Hemolysis Test of Disposable Type Vibrating Flow Pump
Authors: Kobayashi Shinichi , Nitta Shinichi , Yambe Tomoyuki , Sonobe Taro , Naganuma Sigeru , Hashimoto Hiroyuki
Published: November 2008

Abstract: The vibrating flow pump (VFP) can generate high frequency oscillated blood flow. Because of the high frequency driving with short stroke volume, the pump system can be small. The disposable type VFP (D‐VFP) was developed for use for extracorporeal circulation. The elcctromagnetic actuator was detached from the vibrating tube, which was newly designed to be a disposable tube with a jellyfish valve. Hemolysis tests of the D‐VFP, VFP, centrifugal pump, and roller pump were performed in a mock circulation study using goat blood. Plasma free hemoglobin was measured every 15 min under the same conditions. The plasma free hemoglobin of the D‐VFP was 16 mgidl although that of the VFP was 160 mg/dl at 30 min. The plasma free hemoglobin of the centrifugal pump and roller pump at 30 min were 3 mgidl and 9 mg/dl, respectively. The hemolysis performance of the D‐VFP may be studied further as a result of this study. Two important factors affecting hemolysis development may be the materials of which the vibrating tube is made and heat transmission from the actuator. The D‐VFP has a smooth acrylic surface for blood contact compared with the metal surface of old type VFP. The electromagnetic actuator of the VFP surrounded the vibrating tube, so heat from the actuator could be easily transmitted to the blood. Because the D‐VFP has a disposable vibrating tube that is detached from the actuator, heat is not readily transmitted to the blood. A mock circulation study of heat transmission was performed using the D‐VFP and VFP. Results of the heat transmission study showed that the fluid temperature of the D‐VFP was not increased and stayed at room temperature although that of the VFP increased approximately 1°C above room temperature. The D‐VFP may be a good style for the development of the VFP for use for extracorporeal circulation.
Various Problems During Long‐Term Percutaneous Cardiopulmonary Support
Authors: Ihno Toshihiro , Nakagawa Tetsuro , Furukawa Hitoshi , Shimizu Koichi , Egi Kosei , Maemura Taisei , Motomiya Takeshi
Published: November 2008

Abstract: A 54‐year‐old man with a left ventricular free wall rupture following acute anterior myocardial infarction underwent a repair surgery with percutaneous cardiopulmonary support (PCPS). During surgery and postoperatively, PCPS provided sufficient support flow. The patient was successfully weaned from PCPS on the 15th postoperative day and discharged subsequently. In the management of cardiac rupture patients, PCPS has the merit of preventing rupture progression and the advantage of recovery of pulmonary function. However, there are several problems to solve. The support effectiveness and recovery of the patient's heart should be carefully evaluated. Effective left heart decompression also needs to be established. Heparin‐coated circuits still need proper anticoagula‐tion treatment to prevent thrombus formation especially while support flow is low. A circuit construction that allows easier maintenance and safer exchange of oxygen‐ators and pump heads is suggested. Ischemia of the cannulated leg should be prevented by femoral artery perfusion.
Experimental Studies on Three Types of Heparin‐Coated Cardiopulmonary Bypass Circuits
Authors: Baba T. , Morisita K. , Sakata J. , Ito T. , Hachiro Y. , Kazui T. , Abe A. , Komatu S.
Published: November 2008

Abstract: In cardiovascular operations, we have usually used heparin‐coated cardiopulmonary bypass circuits with low systemic heparinization. Three types of heparin‐coated cardiopulmonary bypass circuits are available in Japan: 2 of the 3 have covalent heparin bonding, and the other has ionic heparin bonding. We studied these circuits in ex vivo experiments to explore which were the best in terms of biocompatibility. In this study we compared the Carmeda system (Medtronic) and the Capiox system (Terumo) with covalent heparin bonding, and the Duraflo‐II (Baxter) with ionic heparin bonding, evaluating them in ex vivo experiments. They were primed with fresh human blood, and we studied and compared the platelet counts, fibrinogen, D‐dimmer, beta‐thioguanine (TG), thrombin‐antithrombin complex (TAT), and C3a and C4a of each of them. Additional research will be presented in the future.
Single Needle Venovenous Extracorporeal Membrane Oxygenation Using a Nonocclusive Roller Pump for Rescue in Infants and Children
Authors: Trittenwein Gerhard , Fürst Gerhard , Golej Johann , Frenzle Carola , Burda Gudrun , Hermon Michael , Marx Manfred , Wollenek Gregor , Pollak Arnold
Published: November 2008

Abstract: In 1993, J.Y. Chevalier described a single needle venovenous extracorporeal membrane oxygenation (ECMO) system using a nonocclusive roller pump and alternating clamps for pulmonary support in neonates. We modified this system to use it in older children as well and for additional indications. Introducing a double raceway and 2 different sizes of tubing sets and performing percutaneous approach, we treated 21 children (age 1 day to 49 months) using this system. Indications for treatment were hypoxia and hypoxic induced myocardial dysfunction resulting from pulmonary failure, sepsis, and congenital defects. Of the chiIdren treated for neonatal indications. 7/9 survived. For 2 children ECMO was terminated because of intraventricular hemorrhage (TVH). In the pediatric group 5/7 of the children could be weaned from ECMO, and 2 children died after more than 30 days on ECMO. Two of the children who had been almost completely weaned died later because of therapy withdrawal following a brain death diagnosis. In the cardiac group, 3/5 of the children survived. We conclude that the described system is an effective venovenous ECMO system that reduces invasivity and expenditure.
Rate of reformation of tongue coatings in young adults
Authors: Chérel F , Mobilia A , Lundgren T , Stephens J , Kiger R , Riggs M , Egelberg J
Published: November 2008

Abstract:  Background:  Reviewing the literature, no study on the rate of regrowth of tongue coatings after tongue cleaning was found. Therefore, the purpose of this study in young adults was to study the rate of reformation of tongue coatings after mechanical removal.

Material and Methods:  Thirty‐five dental students participated in the present study. Following preparatory study instructions, baseline examinations were carried out followed by 3 days of observation. At baseline, tongue coating scores (prescraping) were obtained followed by tongue scrapings and determination of the wet weights of the coatings. A second tongue coating score was then obtained within 5 min of the first score (immediate post‐scraping). The subjects returned for repeated tongue coating scores after 1 and 2 days and for final examination after 3 days, which included both tongue coating scores (prescraping and immediate post‐scraping) and determination of the wet weights of the coatings.

Results:  Prior to scraping the tongue at day 0 (baseline), mean tongue coating amounted to a surface extension of 33% of the entire dorsum of the tongue. Scraping the tongue reduced the score to 9%. On average, tongue coating scores had returned to baseline levels on day 2. The mean wet weights of tongue scrapings at days 0 and 3 were similar and amounted to 0.09 ± 0.07 and 0.09 ± 0.06 g, respectively.

Conclusion:  If tongue cleaning is to be recommended, the results of this study in dental students indicate that tongue cleaning should be performed on a daily basis.
A comparative study of oral health knowledge, attitude and behaviour of first and final year dental students of Udaipur city, Rajasthan, India
Authors: Sharda AJ , Shetty S
Published: November 2008

Abstract:  Objective:  To assess and compare differences in oral health knowledge, attitudes and behaviour among first and final year dental students in Udaipur city, Rajasthan, India.

Materials and methods:  In a cross‐sectional study, 182 first year students (59 males and 123 females) and 157 final year students (75 males and 82 females) of the two dental colleges in Udaipur city; Rajasthan, were surveyed using a self‐administered structured questionnaire including 37 multiple choice questions pretested through a pilot survey. The data was analysed using the spss version 10.0. The mean percentage scores, standard deviation and frequency distribution were calculated. The Student’s t‐test and anova test were used as test of significance. The linear regression analysis were used to assess the relation of knowledge, attitude and behaviour.

Results:  The mean % score for oral health knowledge, attitude and behaviour were significantly higher in final year students compared to first year students (P < 0.001). The linear regression analysis showed a statistically significant linear relationship of attitude with the knowledge (P < 0.001) and behaviour with the attitude (P < 0.001) of the students.

Conclusion:  Besides the positive changes revealed in the oral health knowledge, attitude and behaviour, among the students from first to final year of dental studies, preventive behaviour among the students could still be improved.
Determination of n+1 Gamete Transmission Rate of Trisomics and Location of Gene Controlling 2n Gamete Formation in Chinese Cabbage (Brassica rapa)
Authors: Zhang Cheng‐He , Li Xiao‐Feng , Shen Shu‐Xing , Yuan He , Xuan Shu‐Xin
Published: November 2008

A set of trisomics of Chinese cabbage was used for determining the n+1 gamete transmission rate and locating the gene controlling 2n gamete formation on the corresponding chromosome. The results showed that the transmission rates of extra chromosomes in different trisomics varied from 0% to 15.38% by male gametes and from 0% to 17.39% by female gametes. Of the nine F2 populations derived from the hybridizations between each trisomic and Bp058 (2n gamete material), only Tri‐4×Bp058 showed that the segregation ratio of plants without 2n gamete formation to plants with 2n gamete formation was 10.38:1, which fitted the expected segregation ratio of the trisomics (AAa) based on the 7.37% of n+1 gamete transmission through female and 5.88% through male. In other populations the segregation ratios varied from 2.48:1 to 3.72:1, which fitted the expected 3:1 segregation ratio of the bisomics (Aa). These results suggested that the gene controlling 2n gamete formation in Chinese cabbage Bp058 was located on chromosome 4. Further trisomic analysis based on the chromosome segregation and the incomplete stochastic chromatid segregation indicated that the gene locus was tightly linked to the centromere.
Strategic Conservation of Orchard Germplasm Based on Indigenous Knowledge and Genetic Diversity: a Case Study of Sour Orange Populations in China
Authors: Ming Feng , Liu Qi‐Kun , Shi Jin‐Lei , Wang Wei , Lu Bao‐Rong
Published: November 2008

To effectively conserve sour orange (Citrus aurantiumL.) germplasm on two islands at the estuary of the Yangtze River in China, we estimated genetic variation and relationships of the known parental trees and their proposed descendents (young trees) using the fingerprints of random amplified polymorphic DNA (RAPD). Results based on RAPD analyses showed considerable genetic diversity in the parental populations (He= 0.202). The overall populations including the parental and young trees showed slightly higher genetic diversity (He= 0.298) than the parents, with about 10% variation between populations. An unweighted pair group method with arithmetic mean analysis dendrogram based on cluster analysis of the Jaccard similarity among individuals demonstrated a more complicated relationship of the parental and young trees from the two islands, although the young trees showed a clear association with parental trees. This indicates a significant contribution of parental trees in establishing the sour orange populations on the two islands. According to farmers' knowledge, conservation of only one or two parental trees would be sufficient because they believed that the whole populations were generated from a single mother tree. However, this study suggests that preserving most parental trees and some selected young trees with distant genetic relationships should be an effective conservation strategy for sour orange germplasm on the two islands.
Transient Leakance and Infiltration Characteristics during Lake Bank Filtration
Authors: Wiese B. , Nützmann G.
Published: November 2008

Infiltration capacity of bank filtration systems depends on water extraction and hydraulic resistance of the bed sediments. Lakebed hydraulics may be especially affected by clogging, which is dependent on settlement of fine particles, redox potential, and other factors. In the field, most of these processes are difficult to quantify, and thus, when calculating response to pumping the water flux across the sediment surface is assumed to be linearly dependent on the hydraulic gradient. However, this assumption was not adequate to describe conditions at a bank filtration site located at Lake Tegel, Berlin, Germany. Hence, we first assumed the leakage coefficient (or leakance) is spatially distributed and also temporally variant. Furthermore, observations show that the leakance is considerably higher in shallow than in deeper areas; hence, leakance was assumed to be dependent on the existence and thickness of an unsaturated zone below the lake. The proposed explanation of spatial and temporal variability in leakance involves a hypothesis for redox dependent and reversible biogeochemical clogging, supported by geochemical observations in surface water and ground water. Four leakance approaches are implemented in the ground water flow code MODFLOW2000 and calibrated by inverse modeling using the parameter estimation software PEST. These concepts are evaluated by examining the fit to the hydraulic heads, to infiltration measurements, transport modeling results, and considering the degrees of freedom due to the number of calibration parameters. The leakage concept based on the assumption of the influence of an unsaturated zone on clogging processes best explains the field data.
GENDERED HUMAN RIGHTS: THE INTERNATIONAL COMMUNITY'S FAILED RESPONSE TO THE PERSECUTION OF WOMEN
Authors: Campbell Patricia
Published: November 2008

Increasingly women's human rights are being violated as evidenced most recently in Afghanistan and Algeria. The persecution women face is often gender‐related. The international community has repeatedly failed to acknowledge that gender‐related persecution is as acute and as debilitating as other forms of persecution, i.e., ethnic, religious, political opinion. This failure to acknowledge gender‐related persecution has been detrimental to female refugees and has resulted in inconsistent care and protection for them. Today there are well more than 20 million refugees, the majority of whom are female. The gender‐related human rights abuses suffered by women, the failure of the international community to acknowledge this abuse, and the gendered nature of the care and protection female refugees receive, are the foci of this paper.