bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical Model‐Based Indirect Measurements of Blood Pressure and Flow Using a Centrifugal Pump
Authors: Kitamura Tadashi , Matsushima Yuhei , Tokuyama Toru , Kono Satoshi , Nishimura Kazunobu , Komeda Masahiro , Yanai Masamichi , Kijima Toshihiko , Nojiri Chisato
Published: March 2003

Abstract: This article describes a technique offering indirect measurements of pump pressure differential and flow with certain accuracy independent of changes in blood viscosity. This technique is based on noninvasive measurements of the motor current and rotation speed using the physical model equations of the centrifugal pump system. Blood viscosity included in the coefficients of the dynamic equations is first estimated, and then substitution of the estimated viscosity into the steady equations of the model provides pump flow and pressure differential. In vitro tests using a Capiox pump showed a sufficient linear correlation between actual values and their estimates for pressure differential and pump flow. An in vivo test using a 45 kg sheep showed that the proposed algorithm needs robustness for the convergence of estimates of viscosity. An overall evaluation, however, of the developed algorithm/model showed indications of success in terms of efficient computation and modeling.
Cyclosporin A and Therapeutic Plasma Exchange in the Treatment of Severe Systemic Lupus Erythematosus
Authors: Bambauer Rolf , Schwarze Ulrike , Schiel Ralf
Published: March 2003

Abstract: Despite treatment with intensive immunosuppressive drug regimens, often the prognosis of patients suffering from systemic lupus erythematosus (SLE) is poor. Side effects such as infections and malignancies often occur. It was the aim of this trial to assess the effect of immunosuppression, in particular with cyclosporin, and the efficacy, safety, and clinical utility of intermittent treatment with therapeutic plasma exchange (TPE) in comparison to previous intensive therapy strategies using corticosteroids, azathioprine, and/or cyclophosphamide. In this prospective trial, 28 patients (24 women, 4 men, aged 36.3 ± 11.8 years at the diagnosis of SLE) were treated for up to 10 years with drug regimens out of corticosteroids, azathioprine, and/or cyclophosphamide. Then, over a period of up to 8 years, in addition to conventional therapies, especially in active stages of the disease with extremely high concentrations of anti‐DNA, anti‐nuclear antibodies, and circulating immunocomplexes, TPE sessions were carried out depending on symptomatology. In addition, the patients received cyclosporin. Compared with previous treatment modalities, clinical symptoms improved more quickly and more effectively. During the study period of a mean of 5 years, corticosteroids, azathioprine, and cyclophosphamide were reduced by 40 to 100%. No severe side effects were seen. In acute stages of SLE and in forms with persistently high antibody levels, the addition of TPE sessions and cyclosporin as the basic immunosuppressive drug is mostly very effective with regard to improving clinical symptomatology.
Platelet Activation in the Gyro C1E3 Centrifugal Pump: Comparison with the Terumo Capiox and the Nikkiso HPM‐15
Authors: Kawahito Koji , Adachi Hideo , Ino Takashi
Published: March 2003

Abstract: The Gyro C1E3 was developed as a cardiopulmonary bypass pump incorporating the sealless double pivot bearing system. In this study, we evaluated platelet activation induced by the Gyro C1E3 in vitro and in comparison to that of other centrifugal pumps. Rates of increase (RI) for β‐thromboglobulin (β‐TG) and platelet factor 4 (PF4) in the Gyro C1E3 were calculated from in vitro data and compared with the rate of increase in the Capiox (Terumo) and HPM‐15 (Nikkiso) pumps. Fresh human blood was used, and a flow of 5.0 L/min with a ΔP (pressure difference between the outlet and inlet of the pump) of 100 mm Hg employed. RI = Δβ‐TG/ΔN and ΔPF4/ΔN were used where Δβ‐TG is the increase in β‐TG, ΔPF4 is the increase in PF4, and ΔN is the increase in the passing number and where N = Qt/V (t = time, V = priming volume, and Q = flow rate). The mean RI for β‐TG was 0.26 ± 0.05 in the Gyro C1E3, 0.20 ± 0.07 in the Capiox, and 0.15 ± 0.02 in the HPM‐15. The mean RI for PF4 was 0.15 ± 0.03 in the Gyro C1E3, 0.12 ± 0.05 in the Capiox, and 0.09 ± 0.04 in the HPM‐15. While there was no difference in RI for β‐TG and PF4 between the Gyro C1E3 and Capiox, RI for β‐TG and PF4 were significantly higher in the Gyro C1E3 than in the HPM‐15 (p = 0.006 and 0.029). In vitro evaluation using RI for β‐TG and PF4 showed platelet damage caused by the Gyro C1E3 and the Capiox to be nearly equal while the HPM‐15 was less traumatic to platelets than the Gyro C1E3.
Microencapsulated Bovine Chromaffin Cell Xenografts into Hemiparkinsonian Rats: A Drug‐Induced Rotational Behavior and Histological Changes Analysis
Authors: Xue Yilong , Gao Junmao , Xi Zengfei , Wang Zhenfu , Li Xinjian , Cui Xin , Luo Yun , Li Chonghui , Wang Luning , Zhou David , Sun Richard , Sun Anthony M.
Published: March 2003

Abstract: Bovine chromaffin cells were microencapsulated within alginate‐polylysine‐alginate (APA) membranes. Microencapsulated bovine chromaffin cells as well as unencapsulated cells and empty microcapsules were grafted into the brain of hemiparkinsonian rats with 6‐hydroxydopamine (6‐OHDA) lesions. Apomorphine‐induced rotational behavior of the host animals and the survival of the grafted chromaffin cells were examined after transplantation. The animals receiving microencapsulated bovine chromaffin cells showed a significant decrease (17.6–35.6%) in apomorphine‐induced rotation 1 week postimplantation that remained stable for the 10 month test period. Fluorescent histochemistry further revealed that microencapsulation increased the chromaffin cell survival with only a minimum host reaction for up to 10 months posttransplantation while the survival of free, unencapsulated chromaffin cells was only modest and was accompanied by a large inflammatory response. The reduction of apomorphine‐induced rotations was correlated with the survival of bovine chromaffin cells in the host brain. The data indicate that encapsulation of bovine chromaffin cells in APA membranes reduces the host immune response to the xenograft and prolongs the viability of the grafted cells.
Hybrid Artificial Liver Using Hepatocyte Organoid Culture
Authors: Funatsu Kazumori , Ijima Hiroyuki , Nakazawa Kohji , Yamashita Yo‐ichi , Shimada Mitsuo , Sugimachi Keizo
Published: March 2003

Abstract: We developed 2 types of hybrid artificial liver modules using hepatocyte organoid culture. One was a polyurethane foam (PUF)/hepatocyte spheroid packed‐bed module. Hepatocytes spontaneously formed spheroids in the PUF pores, and they maintained liver‐specific functions well for at least 2 weeks in vitro. As a preclinical experiment, a hybrid artificial liver with 200 g porcine hepatocytes was applied to a pig (25 kg) with liver failure and showed that the hybrid artificial liver was effective in support of liver functions and stabilization of general conditions. We established a new technique of hepatocyte organoid formation using centrifugal force. A hepatocyte organoid formed by centrifugation in hollow fibers maintained functions for more than 4 months in vitro. We developed a new sinusoid‐like structure module having hollow fibers arranged by spacers in a micro‐regular arrangement. Inoculated hepatocytes in the extra‐fiber space of the module formed the organoid by centrifugation, and they maintained the functions for at least 1 month in vitro. The results indicated that this module seems to be promising as a hybrid artificial liver.
Development of the MEDOS/HIA DeltaStream Extracorporeal Rotary Blood Pump
Authors: Göbel Christof , Arvand Arash , Eilers Rolf , Marseille Oliver , Bals Christoph , Meyns Bart , Flameng Willem , Rau Günter , Reul Helmut
Published: March 2003

Abstract: The DeltaStream blood pump has been developed for extracorporeal circulation with one focus on potential integration into simplified bypass systems (SBS). Its small size and an embedded electric motor are the basic pump properties. A variation of the impeller design has been performed to optimize hydraulic and hematologic characteristics. A simple impeller design was developed which allows flow and pressure generation for cardiopulmonary bypass applications. The option of a pulsatile flow mode for ventricular assist device applications also was demonstrated in vitro. Impeller washout holes were implemented to improve nonthrombogenicity. The pump was investigated for potential thermal hazards for blood caused by the integrated electric motor. It could be demonstrated that there is no thermal risk associated with this design. Durability tests were performed to assess the lifetime of the pump especially with regard to the incorporated polymeric seal. Seal lifetimes of up to 28 days were achieved using different blood substitutes. In animal tests using either the pump as a single device or in an SBS setup, biocompatibility, low hemolysis, and nonthrombogenicity were demonstrated. In summary, the DeltaStream pump shows great potential for different extracorporeal perfusion applications. Besides heart‐lung machine and SBS applications, ventricular assist and extracorporeal membrane oxygenation up to several days also appear promising as potential applications.
Lateral Approach without Ligament Release in Total Knee Arthroplasty: New Concepts in the Surgical Technique
Authors: Tsai Ching‐Lin , Chen Chih‐Hwa , Liu Tang‐Kue
Published: March 2003

Abstract: A lateral approach without ligament release was performed in 475 primary total knee arthroplasties (TKAs) in 344 patients and 50 revision TKAs in 39 patients. Deformities of the genu varum or valgum were corrected by accurate bone cut; no ligament releases were required other than to achieve adequate exposure. A lateral approach allowed both self‐centering of the extensor mechanism and knee closure in complete flexion. Better range of motion was achieved. More than 90 degree active flexion usually occurred 3 days postoperatively. Postoperative roentgenograms showed all knees had good varus and valgus stability, which was sustained with time, except 1 with late genu recurvatum due to inadequate polyethylene thickness and the other with a broken tibial base plate. Complications such as disruption of patellar blood supply and knee instability, more frequently observed in the medial approach with ligament release, did not occur. The results suggest that this new technique is safe and may give better outcomes.
Experimental Evaluation of the V‐Point Heparin‐Bonding System Applied to a Dense‐Membrane Artificial Lung During 24‐Hour Extracorporeal Circulation in Beagles
Authors: Tashiro Masafumi , Okamoto Taisuke , Sakanashi Yuji , Ao Hushan , Imaizumi Takashi , Tanimoto Hironari , Yanagi Fumiharu , Sugita Michiko , Mimura Rishichi , Terasaki Hidenori
Published: March 2003

Abstract: Heparin was covalently bonded to a hollow‐fiber dense‐membrane artificial lung and circuit using a silane coupling agent and polyethyleneimine as a spacer. This study investigated whether the novel artificial lung could sustain prolonged extracorporeal lung assist (ECLA) by venoarterial bypass in beagles using minimal anticoagulants. We maintained ECLA for 24 h in 3 groups of minimal systemic heparinization, heparinization with the new anticoagulant nafamostat mesilate, and without any systemic anticoagulant. The results were assessed from the functional performance of the artificial lung and by macroscopic and microscopic examination after the experiments. Artificial lung function, hemodynamics, hemogram, and platelet aggregation activity were well maintained in all groups. There was no plasma leakage from the artificial lung. Although several clots were observed in stagnant areas of the artificial lungs and circuits, there was no clot formation inside the artificial lung in any group. This highly biocompatible, heparin‐bonded dense‐membrane artificial lung performed well and safely during prolonged ECLA with blood clotting times less than 120 s.
Errors Involved in the Application of an Imperfect Peritoneal Volume Marker
Authors: Weryński Andrzej , Waniewski Jacek , Marciniak Maria , Baczyński Daniel , Wańkowicz Zofia
Published: March 2003

Abstract: Peritoneal volume markers have been used in numerous studies on fluid transport in peritoneal dialysis. The basic assumption used was that the macromolecular marker was stable and that the free fraction of a label (usually radiolabel) was negligibly small. In this study are presented theoretical investigations on the errors involved in application of an imperfect volume marker containing free fraction of a label. These investigations were used in assessing the errors in calculation of peritoneal volume time course, V, and fluid absorption rate (estimated by volume marker clearance, kE) using data from 20 clinical dwell studies with 1.36% Dianeal dialysis solution and radioiodinated human serum albumin as a volume marker. It has been shown that with an in vitro measured 125I free fraction of 2.72%, the error of kE estimation was 11%. However, the maximal error in estimation of V was only 0.2%. In conclusion, the performed analysis implies that calculation of the peritoneal volume time course during the dwell (with correction for the volume marker elimination) is very reliable, and the existence of a free fraction of a volume marker label results in a negligibly small error. However, even small free fraction of the label results in a significant overestimation of the fluid absorption rate.
The Role of Diastolic Pump Flow in Centrifugal Blood Pump Hemodynamics
Authors: Akimoto Takehide , Litwak Kenneth N. , Yamazaki Kenji , Litwak Philip , Kihara Shin‐ichiro , Tagusari Osamu , Yamazaki Shun‐ich , Kameneva Marina V. , Watach Mary J. , Umezu Mitsuo , Tomioka Jun , Kormos Robert L. , Koyanagi Hitoshi , Griffith Bartley P.
Published: March 2003

Abstract: We tried to verify the hypothesis that increases in pump flow during diastole are matched by decreases in left ventricular (LV) output during systole. A calf (80 kg) was implanted with an implantable centrifugal blood pump (EVAHEART, SunMedical Technology Research Corp., Nagano, Japan) with left ventricle to aorta (LV‐Ao) bypass, and parameters were recorded at different pump speeds under general anesthesia. Pump inflow and outflow pressure, arterial pressure, systemic and pulmonary blood flow, and electrocardiogram (ECG) were recorded on the computer every 5 ms. All parameters were separated into systolic and diastolic components and analyzed. The pulmonary flow was the same as the systemic flow during the study (p > 0.1). Systemic flow consisted of pump flow and LV output through the aortic valve. The ratio of systolic pump flow to pulmonary flow (51.3%) did not change significantly at variable pump speeds (p > 0.1). The other portions of the systemic flow were shared by the left ventricular output and the pump flow during diastole. When pump flow increased during diastole, there was a corresponding decrease in the LV output (Y = −1.068X+ 51.462; R⁁2 = 0.9501). These show that pump diastolic flow may regulate expansion of the left ventricle in diastole.
A New Approach to the Study of Latissimus Dorsi Muscle Vasoreactivity in Rats
Authors: De Angelis Kátia , Cestari Idágene A. , Oliveira Maria Aparecida , Fortes Zuleica Bruno , Irigoyen Maria Cláudia
Published: March 2003

Abstract: In this paper we describe a new approach to the study of changes in latissimus dorsi (LD) muscle microcirculation in rats. The experiments were carried out under anesthesia in normal male Wistar rats (C, n = 6) and in diabetes‐induced rats (D, streptozotocin, 50 mg/kg, i.v., n = 6). The left LD muscle was exposed in order to preserve the proximal tendon with its thoracodorsal nerve and artery. The animal was kept in lateral decubitus over a heating board attached to the mechanical stage of the intravital microscope. The ventral surface of the muscle was exposed over a transparent plate and fixing. The image of the LD vascularization was transferred to the camera system, which was connected to a microcomputer equipped with software (KS‐300, Kontron Elektronik, Munich, Germany) for image storage. The vasoreactivity of LD was analyzed by changes in arteriole diameter after topically administered noradrenaline (0.3 μg/ml) and acetylcholine (300 μg/ml). The microscopic image provided by the described optical setup permitted clear resolution of capillary vessels and a stable preparation over a period of 3–4 h. D rats showed increased vasodilatation (29 ± 2% vs. 18 ± 2.6% in C) and similar vasoconstriction (25.5 ± 3% vs. 27.5 ± 3.3% in C) as compared to C rats. The method described in this paper is suitable for the study of changes in responsiveness of LD arterioles, vessels which represent the major site of vascular resistance and are most actively involved in the control of tissue perfusion.
Nonnstimulated Cardiomyoplasty Improves Hemodynamics in Myocardial‐Infarcted Rats
Authors: De Angelis Kátia , Leirner Adolfo A. , Irigoyen Maria Cláudia , Cestari Idágene A.
Published: March 2003

Abstract: Cardiomyoplasty has been proposed as an alternative surgical treatment for congestive heart failure. The girdling effect of the muscle wrap is believed to reduce diastolic wall stress. We tested the hypothesis that nonstimulated or passive cardiomyoplasty (CDM) would reduce hemodynamic deficits in rats with experimentally induced myocardial infarction (MI). Four groups of animals were studied: intact (C, n = 6), CDM (n = 6), MI by ligation of the left coronary artery (n = 6), and left latissimus dorsi CDM performed 14 days post‐MI (MI + CDM, n = 6). All groups were studied 8 weeks after MI and/or CDM or from the beginning of the experiment in controls. MI rats had a lower mean arterial pressure and higher end‐diastolic pressure (EDP) compared with controls. End‐diastolic pressure (EDP) and the left ventricular‐body weight ratio (LV/BW) were reduced in the MI group after CDM. These data suggest that passive girdling of the heart provided by CDM may improve post‐MI cardiac function.
Ripple Reduction Control of the Undulation Pump Total Artificial Heart
Authors: Saito Itsuro , Chinzei Tsuneo , Mochizuki Shuichi , Abe Yusuke , Isoyama Takashi , Iwasaki Kiyotaka , Suzuki Takafumi , Karita Tatsuro , Ono Toshiya , Kouno Akimasa , Ishimaru Mitsuhiko , Baba Atsushi , Ozeki Toshinaga , Tohyama Takahiro , Kobayashi Shin‐ichi , Imachi Kou
Published: March 2003

Abstract: An undulation pump total artificial heart (UPTAH) in which the revolutions of the motor are converted to undulation motion of a disk has been developed. In an experiment, a goat using the UPTAH survived for 54 days. However, a large ripple was observed in the device's output pressure and flow waveform. In calculating the spectrum of the ripple, we found that the ripple mainly comprised 2 frequency sine waves: 1 having the same frequency as and 1 having double the frequency of the motor revolutions. To reduce the ripple, 2 sine waves, 1 having the same frequency as and 1 having double the frequency of the motor revolutions, were provided to the motor current to modulate the pulse width of the pulse width modulation controlling the motor revolutions. This ripple control method reduced the pressure ripple by 90% in a mock circulation and by 70% in animal experiments. These results revealed that the ripple generated in the UPTAH could be controlled through the use of motor control software.
Effect of Growth Factors on Ex Vivo Bone Marrow Cell Expansion Using Three‐Dimensional Matrix Support
Authors: Tun Thein , Miyoshi Hirotoshi , Aung Tun , Takahashi Satoru , Shimizu Ritsuko , Kuroha Takashi , Yamamoto Masayuki , Ohshima Norio
Published: March 2003

Abstract: To develop a culture system for bone marrow (BM) cell expansion, we examined the effect of growth factors (GFs) on the proliferation and differentiation of BM cells cultured in three‐dimensional (3D) scaffolds of porous polyvinyl formal (PVF) resin. Murine BM cells were cultured for 2 weeks in the PVF resin or in culture dishes as a control, in the presence or absence of 4 GFs (erythropoietin, stem cell factor, interleukin [IL]‐3, and IL‐6). These GFs remarkably stimulated cell proliferation both in PVF and dish cultures. In addition, the PVF cultures showed enhanced cell proliferation in comparison with the corresponding dish cultures. Moreover, PVF cultures with GFs revealed the highest number of colony‐forming units and the highest percentage of hematopoietic progenitor cells (HPCs) among all the cultures examined. Therefore, this 3D PVF culture system with GFs is considered as a potential alternative method for the ex vivo expansion of HPCs.
MTS Colorimetric Assay in Combination with a Live‐Dead Assay for Testing Encapsulated L929 Fibroblasts in Alginate Poly‐l‐Lysine Microcapsules In Vitro
Authors: Bünger C.M. , Jahnke A. , Stange J. , De Vos P. , Hopt U.T.
Published: March 2003

Abstract: Biomaterials such as applied in microcapsules may have harmful effects on encapsulated cells. Up to now, there are no adequate assays available for testing the function and viability of cells in capsules. Therefore, we investigated whether the combination of MTS proliferation assay and live‐dead viability assay is suitable for testing microencapsulated L929 fibroblasts in long‐time culture. Proliferation of L929 cells was shown by a significant increase of formazan absorbance within the first 3 weeks (Day 0: 0.132 ± 0.047; Day 7: 0.404 ± 0.101; Day 14: 0.728 ± 0.239; Day 21: 0.877 ± 0.224) followed by stagnation and decrease thereafter. This was confirmed by an increasing proportion of dead cells measured by the live‐dead assay. Thus, proliferation of encapsulated L929 can be reliably investigated by the MTS assay. In combination with life‐dead assays, the proliferation can be correlated to the survival rate of the encapsulated cells.
Dermatome Electrical Stimulation as a Therapeutic Ambulatory Aid for Incomplete Spinal Cord Injured Patients
Authors: Bajd Tadej , Munih M. , Šavrin R. , Benko H. , Cikajlo I.
Published: March 2003

Abstract: Electrical stimulation of the L‐3,4 dermatome during treadmill walking is proposed as a gait training modality in incomplete spinal cord injured patients. The dermatome stimulation proved to be efficient in diminishing the extensor tone occuring after loading of the paralyzed limb during the stance phase of walking and resulting in improved flexion of the leg during the swing phase.
A Two Year Follow‐Up Study of Common Virus Infections in Hemodialysis Patients in Taiwan
Authors: Kao Tze Wah , Hsu Wei An , Chen Huan Sheng , Chen Wan Yu
Published: March 2003

Abstract: The study was designed to determine whether hemodialysis patients in Taiwan had a different antibody response to common virus infections compared to the normal population. Serum samples from 18 hemodialysis patients and 21 healthy volunteers were obtained every 3 months for 2 years. Geometric mean titers (GMTs) of immunoglobulin G (IgG) antibodies to cytomegalovirus (CMV), herpes simplex virus (HSV), varicella‐zoster virus (VZV), Epstein‐Barr virus (EBV), as well as Type A and Type B influenza viruses (Inf. A, Inf. B) were compared between the patient and the control groups. The prevalence rates and the rates of recurrent infection were similar in both groups. However, the patient group had a higher percentage of persons having persistent EBV and CMV infections (p < 0.05) and also higher GMTs of antibodies nearly the whole year round, especially significant in September and December (p < 0.05). In patients with hepatitis C, their GMTs of EBV, VZV, Inf. A, and Inf. B were higher than those without (p < 0.05).
Nutritional Problems Associated with End‐Stage Renal Disease in the Developing World
Authors: Naicker Sarala
Published: March 2003

Abstract: Protein‐energy malnutrition is a major problem in dialysis patients. There is increased morbidity and mortality in dialysis patients with malnutrition. There are very few published studies on nutritional parameters and adequacy of dialysis from the developing world and especially from Africa. There was a significant improvement in neuromuscular function and nutrition in 22 hemodialysis patients in Egypt with optimization of dialysis dose and nutritional status. In a study of 82 continuous ambulatory peritoneal dialysis (CAPD) patients in Durban, South Africa, there was a reduction in the number of hospital admissions in adequately dialyzed patients (achieving Kt/V of >2.1). In another study of 84 CAPD patients from the same center, 76.2% of patients were assessed as being malnourished, with loss of appetite being an important etiological factor. Strategies to optimize dialysis dose, together with services of a renal dietician, will assist in improving the nutrition of patients with chronic renal failure.
Postcardiotomy Centrifugal Assist: A Single Surgeon's Experience
Authors: Curtis Jack J. , McKenney‐Knox Charlotte A. , Wagner‐Mann Colette C.
Published: March 2003

Abstract: Because of the infrequent application of cardiac assist devices for postcardiotomy heart failure, most published reports include the results of learning curves from multiple surgeons. Between October 1986 and June 2001, a single surgeon used 35 Sarns Centrifugal Pumps as ventricular assist devices in 21 patients with severe hemodynamic compromise after open heart surgery (0.88% incidence). Patients' ages ranged from 39 to 77 (mean, 59.6 years). Three patients required right ventricular assist devices, 4 left ventricular assist devices, and 14 had biventricular assist devices. For all, the indication for application was inability to wean from cardiopulmonary bypass despite multiple inotropes and intraaortic balloon pumping. All were expected to be intraoperative deaths without further mechanical assistance. Patients were assisted from 2 to 434 h (median, 48 h). Fifteen patients (71.4%) were weaned from device(s), and 11 patients (52.4%) were hospital survivors. Actuarial survival in those dismissed from the hospital was 78% at 5 years and 39% at 10 years. Patients facing certain demise after cardiac surgery can be salvaged with temporary centrifugal mechanical assist. Results are competitive with that achieved with more sophisticated devices. Hospital survivors enjoy reasonable longevity.
Serum Neopterin Monitoring and Vitamin E‐Modified, Regenerated Hemodialyzer Membrane Influence on Biocompatibility
Authors: Yoshida Katsunori , Kitauchi Takanori , Kimura Shouki , Yoneda Tatsuo , Uemura Hirotsugu , Ozono Seiichirou , Hirao Yoshihiko
Published: March 2003

Abstract: The exposure of blood to hemodialysis membranes results in numerous phenomena and/or complications in hemodialyzed patients, which have an influence on the quality of life (QOL) of those patients. A vitamin E‐modified regenerated cellulose membrane (E‐membrane) was developed to act as a scavenger for reactive oxygen species causing complications in hemodialysis patients. Neopterin (NEOP) is a metabolite derived from guanosine triphosphate with the production and release of NEOP being induced in monocytes and macrophages by cytokines such as interferon‐γ (IFN‐γ). Serum neopterin levels are shown to be a reactive marker of bioincompatibility of dialysis membranes in hemodialysis patients. The following report evaluates the usefulness of serum NEOP as a marker for the biocompatibility of the E‐membrane hemodialyzer in a clinical study. In the clinical study, where extracorporeal ultrafiltration strategies with E‐membranes were employed, the serum levels of NEOP were lower than those in patients using cellulose triacetate membranes (C‐membranes). In the long‐term evaluation of the biocompatibility of E‐ and C‐membranes, the increase of serum neopterin levels in the C‐membrane was higher than those in the E‐membrane. In conclusion, the evaluation of serum neopterin levels during hemodialysis shows that the E‐membrane has a good biocompatibility in hemodialyzed patients.
The Seventh Prototype of the Mini‐Spindle‐Pump: Does It Fulfill the Expectations of a Short‐Term Pump?
Authors: Hager J. , Klima G. , Koller J. , Fitz A. , Mayr A. , Brandstaetter F.
Published: March 2003

Abstract: According to recent trends to develop implantable nonpulsatile blood pumps for different function modes and times, our intention was and still is to build a Mini‐Spindle‐Pump for a pumping duration of about 14 days. Initial conception for this plan was the premise that the device in a mock circuit should move 4 L of water/min at a speed of 12,000 to 15,000 rpm against a pressure difference of 90 mm Hg between pump inlet and outlet. Despite the development of 6 different prototypes, this project was not realized. Under the above‐mentioned conditions, the main problem of this type of blood pump, the blood trauma, could not be reduced to an adequate level, i.e., the Mini‐Spindle‐Pump is not a high speed pump. Therefore, a revision of the conception was necessary. The device in a mock circuit should transport 5 L of water/min at a speed of about 9,000 rpm against a pressure difference of 90 mm Hg between its inlet and outlet. Considering the implantability of the blood pump, the following measurements for its components were arrived at. The U‐shaped blockformed plexiglas housing was enlarged to 120 × 40 × 40 mm (length of blood chamber 86 mm, inner diameter 27 mm), and the rotor with 5 windings was redesigned at a length of 64 mm (outer diameter 25 mm, inner diameter 6.7 mm). In a mock circuit, this 7th prototype transported with a speed of 9,000 rpm about 10 L of water/min at an afterload of 80 mm Hg. In acute animal experiments with calves up to 15 h of pumping duration, the device showed the expected efficiency. Experiments with a longer pumping duration are necessary to confirm that this prototype will fulfill the criteria of a short‐term pump according to Dr. Y. Nosé's advice.
Development of Totally Implantable Pulsatile Biventricular Assist Device
Authors: Park Chan Young , Park Jun Woo , Lee Jung Joo , Kim Wook Eun , Hwang Chang Mo , Om Kyong‐Sik , Choi Jaesoon , Kim Jongwon , Shim Eun Bo , Jo Young Ho , Min Byoung Goo
Published: March 2003

Abstract: Approximately 10% to 15% of all patients implanted with left ventricular assist devices (LVADs) have required right heart support with another device. The necessity of aggressive biventricular support has already been proposed. Therefore, the totally implantable biventricular assist device (BVAD) was developed. The width of the BVAD main body was 87 mm, the thickness 67 mm, and the height 106 mm, while the weight was 785 g. The automatic control algorithm was developed to prevent lung edema and atrial rupture.
Microvessels of Bulbar Conjunctiva in UPTAH Goats
Authors: Dobšák P. , Vaškuo J. , Baba A. , Isoyama T. , Saito I. , Siegelová J. , Jančík J. , Svačinová H. , Imachi K.
Published: March 2003

Abstract: Aiming to observe directly the microcirculation after total artificial heart (TAH) implantation, we performed a long‐term follow‐up in 2 goats using conjunctival angioscopy. A short segment of parallel arteriole and venule was photographed and analyzed on computer picture program (magnification 40×). Three main parameters were measured: arteriole diameter, venule diameter, and arteriovenous ratio (A/V ratio). The intrathoracically implanted TAH was the undulation pump total artificial heart (UPTAH) with cardiac output of 100 ml/kg/min. To stabilize the peripheral hemodynamics a 1/R biofeedback control system was used. Our results provided only elementary data about morphology of bulbar microvessels. The main finding was the tendency to general vasoconstriction, more intensive on the venous side (*P < 0.05 in one goat). We did not observe any pathological shapes (e.g., tortuosities, varicosities, or sludge); this result could be attributed to the high effectivity of 1/R control method. These preliminary results should be considered only as an attempt to apply the widely used clinical method of conjunctival angioscopy to the conditions of TAH.
Toward an Ecological Approach for the Assessment of Ecosystem Health
Authors: Belaoussoff Svenja , Kevan Peter G.
Published: March 2003

ABSTRACT

Many ecologists express difficulty with the concept of ecosystem health. Ecosystem health must have definable and objective norms that allow for rigorous hypothesis testing for it to be acceptable to those ecologists. One step toward objective measurement of ecosystem health is to characterize ecosystem health by diversity–abundance relationships. The log‐normal relationship between diversity and abundance characterizes taxocenes (i.e., taxonomically related groups that have similar ecological functions). Under conditions of stress, the patterns of diversity and abundance often change and are no longer log‐normal. This change in patterns has been shown for some, but not all, marine and terrestrial taxocenes tested. The interdisciplinary possibilities for using log‐normality, and deviation from it, as a measure of natural and anthropogenic ecosystem health are discussed. The interdisciplinarity of ecosystem health is illustrated with an example of blueberry pollinator decline caused by insecticide spraying in New Brunswick, Canada, and related economic and human health costs.
Monitoring Water Stress Induced Variation in the Remotely Sensed Biomass Pattern of Sardinia (Italy) with Variograms
Authors: Ricotta Carlo , Avena Giancarlo
Published: March 2003

ABSTRACT In Mediterranean climates, the most important ecological factor for natural vegetation as well as for crops is low summer rainfall coinciding with a period of maximum temperatures creating a more or less prolonged period of intense drought. During the summer, water stress enhances the differences between adjacent landscape elements in terms of plant biomass distribution giving way to increased vegetation cover heterogeneity. The aim of this article is to use variogram analysis to quantitatively estimate water stress‐induced oscillations in remotely sensed biomass spatial distribution of Sardinia (Italy).
A Landscape Approach to Biodiversity and Biological Health Planning: The Map of Italian Nature
Authors: Zurlini Giovanni , Amadio Vittorio , Rossi Orazio
Published: March 2003

ABSTRACTThe assessment of conservation values and risks to habitat biological diversity and health is herein addressed based on the occurrence of threatened species within ecotype mosaics and incorporating metrics related to current human disturbances. This assessment is made within a view of biological integrity and ecosystem health. Within the Map of Italian Nature project, that started as a result of Italian national law n. 394/91, such assessments are currently applied to approximately 1.5 million hectares in order to establish new reserves and protected areas, based on their “natural values” and “fragility” at scales in which humans generally influence the condition of the landscape, to get a more representative network of regional biological diversity. Risk and value assessments, based on distribution of species and habitats most threatened with extinction and reduction, are made in reference to the coordination of information on the environment (CORINE) habitat mosaics. To this purpose, digital thematic maps are generated as geographic information systems (GIS) coverages in polygonal (vector) format from satellite, airborne, and observed distribution data of 1) existing land cover habitat types and biodiversity component distributions, and 2) different kinds of man‐induced disturbance. Habitat fragility is estimated either as “potential,” through a simple conceptual model relating fragility to sensitivity and human disturbance, or as “displayed,” inferred from habitat loss. Habitat sensitivity is used to compare biological health within habitat types. The Map of Italian Nature project aims at identifying gaps in the existing reserve network, and is very akin to the gap analysis approach. Map of Italian Nature intends to protect landscape mosaics at the broader scale, based on gaps in protection and threats while including finer scale data on threatened species to make sure they do not fall through the cracks. Results for a pilot study area are presented and the relevance of the approach to biological health and integrity assessments is discussed.
Ecosystem Health and the Political Process: Ullsten and Rapport Revisited
Authors: Wilcox Bruce A. , Fowler Cynthia T.
Published: March 2003

Declining ecosystem health worldwide arguably is partly a consequence of a cultural and political economic disconnect between policy makers and scientists. Previous authors of “Viewpoint” describe this gap in terms of the relative inaction of policy makers in response to warnings from the scientific community. We provide an expanded perspective by considering the sociocultural evolution of political economies, and by contextualizing this dilemma within our overspecialized contemporary society. Our commentary suggests the ecosystem health community can work toward narrowing the policy‐science disjunction despite the disparate cultures of these communities.
Methods for Mapping Forest Sensitivity to Acid Deposition for Northeastern North America
Authors: Arp Paul A. , Leger Wendy , Moayeri Mohammad H. , Hurley J.E.
Published: March 2003

For comparison purposes, two methods are proposed for mapping sustainable acid deposition within the context of natural and managed (harvested) forest biomass growth in Northeastern North America. One method uses existing geospatial data for forest cover type, soil type, local climate, topography, and atmospheric deposition. The other method uses data specific to well‐studied sites. Maps will be developed that show the spatial distributions of sustainable acid deposition rates by tree type, eco‐unit, and local forest disturbance regimes (by harvest method). Additional maps will be produced to show where these rates are likely exceeded, and by how much. The information so generated will be presented to policy and decision makers who deal with forest health and abatement control measures regarding regional sulfur (S) and nitrogen (N) emissions.
Reduction of Migrainous Headaches During the Use of Acenocoumarol
Authors: van Puijenbroek E.P. , Egberts A.C.G. , Trooster J.F.G. , Zomerdijk J.
Published: March 2003

Disappearance of migraine during the use of warfarin and of phenprocoumon has been described in sporadic case reports?1,2 Treatment with heparin has also been associated with a reduction of migrainous headaches.3 Recently, the Netherlands Pharmacovigilance Foundation LAREB received a case reportconcerning the diminution of migrainous headaches associated with the use of the vitamin K antagonist, aceno‐coumarol.
Analgesic Use in Cluster Headache
Authors: Gallagher R. Michael , Mueller Loretta , Ciervo Carman A.
Published: March 2003

Cluster headache is a brutal affliction characterized by excruciating pain with relatively brief, but frequent attacks. Because of the short duration of the attacks and the tremendous intensity of pain, symptomatic analgesics are often not effective. However, inhalation oxygen, while being cumbersome, is reported to be effective in the majority of sufferers.

To assess the practical effectiveness and use of analgesics and/or oxygen, a review of 60 cluster patients was conducted. At initial evaluation, 48 patients had accepted oral analgesics and 51 patients accepted inhalation oxygen for breakthrough headaches. After acceptable prophylactic treatment was established, 65% of patients who accepted analgesics continued their use, although most reported only minimal relief. Only 31% of patients who accepted oxygen continued its use, in spite of the fact that most sufferers reported significant relief..

this brief study, it appears that cluster headache patients prefer to use analgesics for reasons that are not solely for relief of pain, and that patients decline the use of oxygen for reasons other than lack of effectiveness.
The Confirmation of a Biochemical Marker for Women's Hormonal Migraine: The Depo‐Estradiol Challenge Test
Authors: Lichten Edward M. , Lichten Jason B. , Whitty Albert , Pieper David
Published: March 2003

Precis: Will estrogen withdrawal cause migraines in post‐menopausal women?

Objective: To record the changes in serum estradiol and total estrogen levels after an intramuscular estradiol injection in menopausal subjects and then record any subsequent migraine occurrence.

Design: Open selection process, comparative trial.

Patients: Twenty‐eight postmenopausal women volunteers were given 5 mg depo‐estradiol cyprionate as an intramuscular injection. Sixteen (migraine group) had a history of severe, cyclic, menstrually related migraine attacks before becoming menopausal. Twelve (control group) had no history of migraine or headache. All volunteers were on continuous estrogen replacement therapy at the beginning of the study. Progestins were not used in the study.

Main Outcome Measures: Serum estradiol and total estrogen levels were measured prior to the depo‐estradiol injection and on subsequent days 4, 7, 14, 21, and 28.

Results: Total estrogen and estradiol levels varied greatly at every measured interval. Menopausal complaints of vasomotor symptoms were relieved for at least the first 2 weeks of the study. No member of the control group reported a migraine during the month. However, a severe migraine was reported by all 16 women with a history of migraine. The average day of the migraine occurrence was 18.5 ± 2.8. The serum level of estradiol on the day of the worst migraine was 46.4 ±± 5.6 pg/mL. The significance of these findings was at the 95% confidence level.

Conclusions: This study confirms two factors about menopausal hormonal migraine: (1) it can be precipitated by a drop in serum estrogen levels, and (2) a period of estrogen priming is a necessary prerequisite. This study also identifies that there are two biologically different populations of postmenopausal women: (1) those who developed migraine after a single depo‐estradiol injection, and (2) those who did not. By understanding that in addition to the biological predisposition to migraine there exists the biochemical cofactor of falling estrogen levels, we may better understand this phenomenon and develop means to prevent its occurrence.
Posterior Ischemic Optic Neuropathy Associated With Migraine
Authors: Lee Andrew G. , Brazis Paul W. , Miller Nail R.
Published: March 2003

Anterior ischemic optic neuropathy is a well‐recognized clinical syndrome that has been described in patients after an episode of migraine with visual aura (classic migraine) and, less commonly, after an episode of visual aura without headache (acephalgic migraine). Little emphasis, however, has been placed on migraine associated retrobulbar or posterior ischemic optic neuropathy. We report two cases of visual loss presumed to be due to posterior ischemic optic neuropathy that occurred In the setting of otherwise typical migraine episodes. We review the English language literature on Ischemic optic neuropathy associated with migraine. Although most cases of ischemic optic neuropathy associated with migraine are of the anterior variety, posterior ischemic optic neuropathy should be considered in the differential diagnosis of any patient with acute loss of vision and evidence for a retrobulbar optic neuropathy, during or after an attack of migraine headache or following an otherwise typical episode of visual aure without headache (acephalgic migraine).
SUNCT Syndrome. Statuslike Pattern
Authors: Pareja Juan A. , Caballero Vicente , Sjaastad Otsar
Published: March 2003

Four SUNCT patients with a clinical “SUNCT status” witnessed by the investigators are reported. Such an extreme aggregation of typical attacks lasting for the better part of the day, 1 to 3 days in a row has not previously been observed. Appropriate supplementary examinations ruled out an intracranial lesion in all four patients. Indeed an observation period of more than 5 years speaks against a symptomatic etiology of SUNCT in these cases. Although rarely seen, clinical status may be a feature of the SUNCT syndrome.
Serotonin Syndrome Presenting With Migrainelike Stroke
Authors: Molaie Majid
Published: March 2003

Serotonin syndrome is the result of the drug interaction that enhances serotonergic tone in the central nervous system. The neurological manifestations are transient in most of the reported cases with rare fatality.

Case Description.—A 30‐year‐old woman developed ischemic infarction of the right temporoparietal and cerebellar hemispheres 48 hours after administration of a large dose of clomipramine. This drug was given within 24 hours of discontinuation of high‐dose fluoxetine, both of which are known to enhance serotonergic tone in the central nervous system.

The distribution of the ischemic infarction in this case did not respect the major territorial arteries and was similar to spreading oligemia/ischemia that is described in migraine. A similar pathogenesis may exist for stroke in serotonin syndrome and in migraine.
A Late ‘Migraine’: The Only Symptom of an Intrasellar Aneurysm
Authors: Narbone Maria Carola , Rao Renata , Grugno Rosario , Pellicanò Margherita
Published: March 2003

The history of a 62‐year‐old woman affected by an intrasellar aneurysm is described. A migrainelike headache was, for many years, her only complaint.
Chronic Daily Headache in Children and Adolescents:Current Status and Recommendations for the Future
Authors: Gladstein Jack , Holden E. Wayne , Winner Paul , Linder Steven ,   Pediatric Committee of the American Association for the Study of Headache
Published: March 2003

The Pediatric Committee of the American Association for the Study of Headache was created in 1994 to develop a plan for comprehensively addressing global issues of headache in childhood. It was the impression of clinicians and researchers with an interest in childhood headaches that a clearer focus was needed to facilitate progress in the study and management of pediatric headache. It was further felt that approaches to treatment and outcomes, as well as assessment and classification schema for pediatric patients needed to be examined separately. The goal of the committee is to integrate anecdotal, clinical, and research expertise into a plan for addressing headaches in the pediatric population in the future. During the last 5 years, substantial attention has been devoted to chronic daily headache, primarily in adult populations. It is the purpose of this paper to review the literature of chronic daily headache in children, and propose areas for further exploration, given the recent emergence of interest in this diagnostic entity.
Chewing Gum Headaches
Authors: Blumenthal Harvey J. , Vance Dwight A.
Published: March 2003

Aspartame, a popular dietetic sweetener, may provoke headache in some susceptible individuals. Herein, we describe three cases of young women with migraine who reported their headaches could be provoked by chewing sugarless gum containing aspartame.