bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption of Microorganism Components by Lixelle Beads
Authors: Tsuchida Kenji , Takemoto Yoshiaki , Nakatani Tatsuya , Nakamura Takahiro , Sugimura Kazunobu , Yamamoto Keisuke
Published: March 2003

Abstract: We reported previously that Lixelle, which was used for beta‐2 microglobulin (BMG) adsorption columns, could adsorb not only BMG but also inflammatory cytokines. We then were interested in the application of Lixelle to patients with systemic inflammatory response syndrome (SIRS) and tried to find out its ability to adsorb microorganism components in vitro using lipopolysaccharide (LPS) (E. coli: B8), endotoxin (ET) containing water, and peptidoglycan (PG: Micrococcus luteus). The initial concentrations of each solution were LPS (ET: 29,135 EU/L), contaminated water (ET: 3,523 EU/L), and PG (67.1 ng/ml) and 2.5 ml of each of the stock solutions and adjusted diluted solutions contained 0.5 ml of Lixelle beads. After shaking at 37°C for 2 h, ET in the solutions was determined by the ET specific‐limulus amebocyte lysate (ES‐LAL) method and PG by the silkworm larbae plasma (SLP) method. The results revealed that even when ET concentrations in LPS and contaminated water were high, the samples containing Lixelle beads showed significant decreases. There was some adsorption of PG but no significant differences. Thus, Lixelle beads can adsorb not only BMG but also microorganism components such as ET and PG. These findings, together with the ability to adsorb inflammatory cytokines by Lixelle, show the possibility of application for the treatment of infectious SIRS.
Artificial Grasping System for the Paralyzed Hand
Authors: Ferrari de Castro Maria Claudia , Cliquet Alberto
Published: March 2003

Abstract: Neuromuscular electrical stimulation has been used in upper limb rehabilitation towards restoring motor hand function. In this work, an 8 channel microcomputer controlled stimulator with monophasic square voltage output was used. Muscle activation sequences were defined to perform palmar and lateral prehension and power grip (index finger extension type). The sequences used allowed subjects to demonstrate their ability to hold and release objects that are encountered in daily living, permitting activities such as drinking, eating, writing, and typing.
Water‐Soluble Vitamin Levels in Patients Undergoing High‐Flux Hemodialysis and Receiving Long‐Term Oral Postdialysis Vitamin Supplementation
Authors: Descombes Eric , Boulat Olivier , Perriard François , Fellay Gilbert
Published: March 2003

Abstract: The prescription of multivitamin supplements for dialysis patients is routine practice, but the doses prescribed differ greatly from one dialysis center to another. Few data are available concerning long‐term vitamin supplementation and its effects on patients either on high‐flux hemodialysis or receiving postdialysis supplementation. For several years, we have systematically prescribed to our patients an oral postdialysis multivitamin supplement containing thiamine hydrochloride 100 mg, riboflavin 20 mg, pyridoxine hydrochloride 50 mg, folic acid 6 mg, and ascorbic acid 500 mg. The aim of this study was to perform a cross‐sectional long‐term evaluation of the vitamin levels in patients who received this vitamin supplement for at least 12 months. We also were interested in investigating the plasma oxalic acid and total homocysteine levels associated with the long‐term prescription of these vitamin supplements. Thirty‐three patients on high‐flux dialysis were studied. Vitamin levels and/or vitamin‐dependent enzymatic activities were within the normal range (N) in all patients. The mean results (±SD) were plasma ascorbic acid 13.6 ± 6.4 mg/L (N > 4), plasma folate 14.1 ± 1.1 μg/L (N > 3), for vitamin B1, α‐ETK 1.02 ± 0.02 (N < 1.18) and ETKo 100 ± 13 U/L (N > 70), for vitamin B2, α‐EGR 1.00 ± 0.07 (N < 1.52) and EGRo 1282 ± 213 U/L (N > 672), and for vitamin B6, α‐EGOT 1.34 ± 0.10 (N < 1.8) and EGOTo 380 ± 84 U/L (N > 228). Plasma oxalic acid was higher than normal in all patients (mean = 61 ± 15 μmol/L, N < 33). However, all patients had oxalic acid levels within the range reported in the literature for patients not taking extra ascorbic acid. Mean total homocysteine was 24 ± 8 μmol/L with only 4 patients (12%) having normal levels (N < 15). In conclusion, the postdialysis supplement given provides adequate vitamin levels in almost all patients in the long term. Postdialysis prescription allows an optimal compliance with the treatment, is well accepted by the patients, and is cost‐effective.
Calcification of Leaflets from Porcine Aortic Valves Crosslinked by Ultraviolet Irradiation
Authors: Suh Hwal , Hwang Yu‐Shik , Park Jong‐Chul , Cho Bum Koo
Published: March 2003

Abstract: Glutaraldehyde (GA)‐pretreated porcine aortic valves are generally used as a bioprosthetic valve, but gradual calcification of the leaflets often occurs. It has been hypothesized that the crosslinking agent, GA, stabilizes and perhaps modifies phosphorus‐rich calcifiable structures in the bioprosthetic tissue. This is supported by our findings that calcium deposition is induced rapidly in GA‐pretreated leaflets in comparison with ultraviolet (UV) irradiated leaflets. After 3 days of in vitro calcification test, calcium levels were 257.6 ± 23.5 μg/cm3 in GA‐pretreated, 57.7 ± 10.2 μg/cm3 in the control, and 108.6 ± 7.6 μg/cm3 in 24 h UV irradiated leaflets. The calcium level in all test groups increased as time proceeds and the calcium level of GA‐pretreated leaflets was significantly higher than the control and UV irradiated leaflets during test. This rapid calcium deposition on the GA‐pretreated leaflets may be due to residual aldehyde groups after pretreatment. The exposure time of UV irradiation was not significantly correlated with the extent of calcification. After 14 days of the test, calcium levels in leaflets UV irradiated for 1, 2, 4, and 24 h were 502.6 ± 12.3 μg/cm3, 547.5 ± 34.1 μg/cm3, 564.3 ± 26.1 μg/cm3, and 543.0 ± 55.5 μg/cm3. In all test groups, [Ca]/[P] molar ratio decreased toward that of hydroxyapatite as the predominant mineral phase as time proceeds. This study suggests that UV irradiation can be considerable as an efficient crosslinking method to surmount the side effects induced by GA‐pretreatment and may endow tissue with mechanical property.
Supplemental Systemic Oxygen Support Using an Intestinal Intraluminal Membrane Oxygenator
Authors: Gross Brian D. , Sacristán Emilio , Peura Robert A. , Shahnarian Albert , Devereaux Daniel , Wang Hia‐Long , Fiddian‐Green Richard
Published: March 2003

Abstract: An intraluminal membrane oxygenator (IMO) prototype was surgically inserted in the ileum and evaluated as a method of supporting systemic oxygenation in an acutely hypoxemic porcine model. Animals were assigned randomly to the test (n = 12) or the control (n = 8) groups, which underwent identical protocols with the exception of the O2 flow in the IMO device, which was shut off in the control group. In each case, hypoxia was induced by a reduction in the inspired oxygen fraction (Fio2) to 0.14. A highly significant improvement (p < 0.005) in arterial and venous O2 content and lower arteriovenous O2 difference (p < 0.05), cardiac output, and hemoglobin (p < 0.005) were found in the test group during hypoxia. The results show that it is possible to meet a physiologically significant portion of the body's O2 demands via the intestine during respiratory hypoxia and suggests that similar devices may be of significant potential value as a supplemental oxygenation device in cases of respiratory distress.
Continuously Maintaining Positive Flow Avoids Endocardial Suction of a Rotary Blood Pump with Left Ventricular Bypass
Authors: Akimoto Takehide , Yamazaki Kenji , Litwak Philip , Litwak Kenneth N. , Tagusari Osamu , Mori Toshio , Antaki James F. , Kameneva Marina V. , Watach Mary J. , Umezu Mitsuo , Tomioka Jun , Kormos Robert L. , Koyanagi Hitoshi , Griffith Bartley P.
Published: March 2003

Abstract: This study showed the usefulness of maintaining positive pump flow to avoid endocardial suction and as an assist bypass. Three calves were implanted with centrifugal pumps. Hemodynamics and pump parameters were measured at varying pump speeds (from 1,100 to 2,300 rpm). In each test pump, speed was adjusted to create 3 hemodynamic states: both positive and negative flow (PNF), positive and zero flow (PZF), and continuously positive flow (CPF). The pump flow volume was determined during systole (Vs) and diastole (Vd). Vs in PNF was 29.6 ml and was not significantly different from Vs in PZF (p > 0.15). Vd in PNF was significantly different from Vd in PZF (p < 0.05). All bypass rates of PNF were over 30% of pulmonary flow. All PZF bypass rates were between the PNF rate and the CPF rate. These data showed that PZF satisfied the minimum requirement of assist flow and was under 100% bypass. Thus, PZF may avoid endocardial suction.
Clinical Evaluation of Heparin‐Coated Circuits for Routine Coronary Artery Bypass Grafting Surgery: A Prospective Randomized Study
Authors: Collart Frédéric , Caus Thierry , Pomane Claude , Pellissier Véronique , Chi Yfan , Montiès Jean‐Raoul , Mesana Thierry
Published: March 2003

Abstract: The aim of this study was to demonstrate the clinical and biological benefits of heparin‐coated circuits in routine coronary artery bypass grafting (CABG). A prospective, randomized study was conducted in 80 patients undergoing routine CABG. Patients were randomized to either noncoated circuits (Group 1) or heparin‐coated circuits (Group 2). A complete clinical evaluation was performed preoperatively at Days 0, 1, 2, and 3 and at discharge day and combined with extensive laboratory tests for hemostasis and inflammatory response. This study did not prove any major statistically significant clinical benefit of heparin‐coated circuits in low risk patients. Postoperative bleeding, significantly less in the heparin‐coated group, did not decrease significantly the number of transfused patients. Biological values were not changed significantly except for factor II and monocytes, which were higher in Group 2. Heparin‐coated circuits offer minimal clinical and biological benefits for routine CABG surgery. However, they may prove beneficial for complex procedures or at‐risk patients.
Development of a DNA Immunoadsorbent: Coupling DNA on Sepharose 4FF by an Efficient Activation Method
Authors: Kong De‐Ling , Schuett Wolfgang , Boeden Hans‐Friedrich , Kunkel Siegfried , Holtz Manfred , Matic Goran , Yamada Ryo , Yu Yao‐Ting , Klinkmann Horst
Published: March 2003

Abstract: To remove anti‐DNA antibodies from a patient's plasma with systemic lupus erythematosus (SLE), a DNA immunoadsorbent was developed by covalently coupling calf thymus DNA on activated Sepharose 4FF. Sepharose 4FF was activated with 5‐norbornene‐2,3‐dicarboximido carbonochloridate (Cl‐CO‐ONB), which was proven to be a very effective method for preparation of affinity chromatographic adsorbents. The activation was carried out in dry acetone using 4‐(dimethylamine)pyridine (DMAP) and triethylamine (TEA) as catalysts at 4°C or at room temperature. The coupling of DNA to the activated support was investigated as a function of pH, temperature, time, concentration of DNA, and activation level. It was found that the pH for optimal coupling is 3.0, and the amount of coupled DNA increases with an increase either in the concentration of DNA or the activation level. The maximum amount of coupled DNA could reach 1.0 mg DNA/ml support. The incubation of 5 to 20 ml of SLE plasma with 1.0 ml of adsorbent resulted in an 80 to 90% decline in the anti‐DNA antibody level. Nonspecific adsorption for normal IgG and total protein is less than 15%.
Scanning Electron Microscopic Analysis of Arterial Line Filters Used in Cardiopulmonary Bypass
Authors: Kim Won Gon , Kim Ki‐Bong , Yoon Chul Jong
Published: March 2003

Abstract: The clinical value of arterial line filters is still a controversial issue. Proponents of arterial line filtration argue that filters remove particulate matter and undissolved gas from circulation while opponents argue the absence of conclusive clinical data. We conducted scanning electron microscope (SEM) studies of arterial line filters used clinically in the cardiopulmonary bypass circuits during adult cardiac surgery and analyzed the types and characteristics of materials entrapped in the arterial line filters. Twelve arterial line filters were obtained during routine hypothermic cardiopulmonary bypass in 12 adult cardiac patients. The arterial line filter was a screen type with a pore size of 40 μm (Baxter Health Care Corporation, Bentley Division, Irvine, CA, U.S.A.). After opening the housing, the woven polyester strands were examined with SEM. All segments examined (120 segments, each 2.5 × 2.5 cm) contained no embolic particles larger in their cross‐sectional area than the pore size of the filter (40 μm). The origins of embolic particulates were mostly from environmental foreign bodies. This may suggest a possible need for more aggressive filtration of smaller particulates than is generally carried out at the present time.
Transperitoneal Transport of Glucose In Vitro
Authors: Czyżewska Krystyna , Szary Beata , Waniewski Jacek
Published: March 2003

Abstract: The effect of fluid mixing intensification, damage of mesothelial cells, gentamicin, and icodextrin on the diffusive glucose transport across the peritoneal membrane were evaluated in in vitro studies. A mathematical model of mass transport was used to calculate the diffusive permeability, expressed as a diffusive permeability coefficient (P). In the control conditions, the rate of glucose transfer from the interstitial to the mesothelial side of membrane (I→M) and in the opposite direction (M→I) remained constant, and the P value at mean was 2,731 ± 1,493 × 10−4 (cm × s−1). The change of the stirring rate from 5.5 to 11 ml/min increased P values by about 74% for transport direction I→M and 58% for M→I, and the change from 11 to 22 ml/min enhanced P at mean by about 42% for both directions. The damage of the mesothelial layer, using sodium deoxycholate (2.5 mmol/L; 103.6 mg%), increased the glucose transfer from the interstitial to the mesothelial side of the peritoneum by 41% and to the opposite direction by 70%. Addition of icodextrin to the glucose solution increased glucose bidirectional transport at mean by about 14% for I→M and 24% for M→I. Furthermore, gentamicin did not change the I→M transfer, but diminished M→I transport by about 12%. In conclusion, the reduction of unstirred fluid layers at the mesothelium and the interstitium‐fluid interfaces, removal of mesothelium, and addition of icodextrin increased the diffusive glucose transport in vitro; unstirred fluid layers restricted glucose transfer (I→M) more than the mesothelium; and peritoneal glucose transport, directed from the mesothelial to the interstitial side of the peritoneum, decreased slightly after the addition of gentamicin.
From a Lab Type to a Product: A Retrospective View on Impella's Assist Technology
Authors: Siess Thorsten , Nix Christoph , Menzler Frank
Published: March 2003

Abstract: A lab type is best described by its value as a result of its handcrafted uniqueness in small numbers. Logically, there is not one lab type like another, and the fact that it has been realized does not mean that this special effort can be easily reproduced. Furthermore, most lab types have undergone stand alone test runs revealing fingerprints rather than universal results at a 20% effort to 80% effect ratio. A product development, on the other hand, is best described by an 80% effort to 20% effect ratio in terms of measurable results. Products are producible and cost effective goods which are well documented and have undergone numerous test runs and test procedures assuring safety and quality, a basic requirement for market approval and cost effective marking. Based on the intravascular pump technology, comprising a sensorized axial flow pump with an integrated micromotor, the iterative dependence of the product development on lab types is demonstrated showing in particular the importance of having highly developed lab types before initiating the product development. By example, we demonstrated that high product quality has a greater impact on the reduction of blood damage than numerous redesigns. Reengineering issues are addressed, which are part of the product development process. Furthermore, the previously mentioned technology serves as a platform leading directly from the perioperative biventricular system to a 7 day pump as well as a miniaturized 12 Fr version.
The HeartMate II: Design and Development of a Fully Sealed Axial Flow Left Ventricular Assist System
Authors: Burke David J. , Burke Edward , Parsaie Farzad , Poirier Victor , Butler Kenneth , Thomas Douglas , Taylor Lynn , Maher Timothy
Published: March 2003

Abstract: Our group is developing the control and power transmission components required to implement a permanent and fully sealed left ventricular assist system (LVAS). Starting with the percutaneously powered HeartMate II blood pump, our development efforts are focused in the following areas: a complete redesign of the transcutaneous energy transmission system (TETS) to include a rectification network and autonomous voltage regulation within the secondary coil, a hermetically sealed electronics package containing a miniaturized implementation of the existing redundant drive and control electronics with several power‐input options, an implanted rechargeable lithium ion battery pack capable of providing up to 1 h of untethered operation, implantable electrical connectors that allow components to be connected after placement in the body or to be replaced if needed, and a radio telemetry subsystem to transmit diagnostic information and to permit remote adjustment of selected parameters.
A Comparison Between Epoetin Omega and Epoetin Alfa in the Correction of Anemia in Hemodialysis Patients: A Prospective, Controlled Crossover Study
Authors: Bren Andrej , Kandus Aljoša , Varl Janez , Buturović Jadranka , Ponikvar Rafael , Kveder Radoslav , Primožič Stanislav , Ivanovich Peter
Published: March 2003

Abstract: The objective of the study was to evaluate and compare the safety and effectiveness of epoetin omega (produced in baby hamster kidney cells) and epoetin alfa (produced in Chinese hamster ovary cells) in sustaining the correction of anemia in maintenance hemodialysis patients. The study, a prospective and controlled crossover, was completed in 38 stable patients treated with both epoetins for 24 weeks. Group A (17 patients) started with epoetin omega, and Group B (21 patients) started with epoetin alfa. After 24 weeks, a 4 week crossover (wash out) was made: Group A was switched to epoetin alfa and group B to epoetin omega for the next test period of 24 weeks. Both epoetins were administered subcutaneously after each dialysis. Doses were adjusted with the aim of maintaining a target hemoglobin level between 10 and 12 g/dl (hematocrit 30% to 35%). The mean weekly dose of epoetin omega/kg body weight (BW) was 67 ± 43 U. The mean weekly dose of epoetin alfa/kg BW was 86 ± 53 U. The average of all mean values of hemoglobin (Hb) during treatment with epoetin omega was 11.4 ± 0.7 g/dl (hematocrit 34 ± 2%), and during treatment with epoetin alfa was 11.3 ± 0.7 g/dl (hematocrit 33 ± 2%) (not significant). Thromboses of vascular access occurred in 3 patients during an epoetin omega treatment and in 3 patients during epoetin alfa treatment. At the site of injection, only 1 patient described a mild pain when treated with epoetin omega and only 6 patients when treated with epoetin alfa. In conclusion, both epoetin omega and epoetin alfa were effective in correcting the anemia of all studied patients. However, lower doses of epoetin omega were needed to maintain the same target hemoglobin level. No serious side effects with either epoetin were noted. The authors believe that additional comparisons of different epoetin preparations should be performed and will provide better insight into their biological activity and clinical responsiveness.
Is Roller Pump Induced Tubing Rupture a Clinical Possibility?
Authors: Kim Won Gon , Chung Chan Il , Cho Sang Rock
Published: March 2003

Abstract: We analyzed the effects of variations in the diameter of silicone rubber and polyvinyl chloride (PVC) tubings on the likelihood of tubing rupture during modeling of accidental arterial line clamping in cardiopulmonary bypass (CPB) with a roller pump. A closed CPB circuit constructed with a roller pump was tested with both PVC and silicone rubber tubings of 1/2, 3/8, and 1/4 inch internal diameter. Arterial line pressure was monitored, and an occlusive clamp was placed across the tubing distal to the pressure monitor site to model an accidental arterial line occlusion. A charge coupled device camera with 512 (horizontal) × 492 (vertical) pixels was installed above the roller pump to measure tubing diameters at pump outlet where the maximum deformations (distension) of the tubings occurred. Quantitative measurement of the changes of tubing diameters with the change of arterial line pressure was performed using computerized image processing techniques. A visible change of tubing diameter was generally noticeable by around 250 psi of arterial line pressure, which was already very high. By 1,500 psi, the PVC tubings showed an increase of diameter between 5% to 10% while the silicone rubber tubings showed an increase between 20% to 25%. Silicone rubber tubings of all sizes showed greater distensibility than PVC tubings of equivalent size. In conclusion, although roller pump induced tubing rupture remains a theoretical problem during CPB in terms of the inherent mechanism of the pump, in reality such an occurrence is impossible in real clinical conditions.
Design of a New Pulsatile Bioreactor for Tissue Engineered Aortic Heart Valve Formation
Authors: Dumont Kris , Yperman Jessa , Verbeken Erik , Segers Patrick , Meuris Bart , Vandenberghe Stijn , Flameng Willem , Verdonck Pascal R.
Published: March 2003

Abstract: Evidence has been gathered that biomechanical factors have a significant impact on cell differentiation and behavior in in vitro cell cultures. The aim of this bioreactor is to create a physiological environment in which tissue engineered (TE) aortic valves seeded with human cells can be cultivated during a period of several days. The bioreactor consists of 2 major parts: the left ventricle (LV) and the afterload consisting of a compliance, representing the elastic function of the large arteries, and in series a resistance, mimicking the arterioles and capillaries. The TE aortic valve is placed between the LV and the compliance. With controllable resistance, compliance, stroke volume and frequency, and hydrodynamic conditions can be changed over a wide physiological range. This study resulted in a prototype of a compact pulsatile flow system for the creation of TE aortic valves. In addition a biocompatibility study of the used materials is performed.
End‐Stage Renal Disease and Its Treatment in Venezuela
Authors: Bellorin‐Font Ezequiel , Milanés Carmen Luisa , Rodríguez‐Iturbe Bernardo
Published: March 2003

Abstract: In Venezuela there are 3,234 new cases (132 per million population [pmp]) requiring renal replacement therapy each year, and only 40% of these are admitted to the different modalities of dialysis. In the year 2000, there were 195 patients pmp in chronic hemodialysis (4,700 patients). Diabetes, glomerular diseases, and hypertension account for more than 60% of the patients in chronic dialysis. Gross mortality in hemodialysis is around 20%, and cardiovascular causes are the primary cause of death (39.5%). Hospital admission in the dialysis patients amounts to 4.6 days/patient/year. Rehabilitation is inadequate. Only 45% of the dialysis patients report normal home or work activities. Transplantation in Venezuela has a general graft survival rate of 83% at 1 year (90% for living related grafts) and 50% (64% for living related grafts) at 10 years. Future tendencies include emphasis in preventive strategies, including early detection and treatment of diabetes and hypertension, as well as efforts to increase the rate of renal transplantation.
Hypertension and End‐Stage Renal Disease in the Developing World
Authors: El‐Khashab Omar
Published: March 2003

Abstract: Hypertension is an important primary etiology of end‐stage renal disease as well as a major factor responsible for progression of renal disease due to other causes. Multiple genetic and environmental factors are responsible for the variable prevalence of hypertension in various parts of the world. Although the frequency of hypertension awareness and control is very modest in the developing world, nephroangiosclerosis seems to be more common in the developed countries. Factors responsible for this discrepancy as well as various strategic measures to control hypertension and its impact on renal disease are discussed.
A Prototype HeartQuest Ventricular Assist Device for Particle Image Velocimetry Measurements
Authors: Day Steven W. , McDaniel James C. , Wood Houston G. , Allaire Paul E. , Song Xinwei , Lemire Phillip P. , Miles Scott D.
Published: March 2003

Abstract: The objective of this study is to fully characterize the flow within the HeartQuest ventricular assist device (VAD), a magnetically levitated centrifugal VAD, using particle image velocimetry (PIV) to identify regions of potential high shear or stagnation and validate and refine computational models of the flow. An acrylic model of the pump was designed and constructed to allow optical access into all interior regions of the pump. The geometry of the exterior housing and the use of a novel working fluid make quantitative measurements of velocity within the exit volute, blade passage, cut‐water, blade tip clearance, and pump inlet possible. Highly accurate velocity measurements using particle PIV have been made in one region (the inlet elbow), and measurements in the other critical regions of the pump will be made. These measurements are used for investigation of regions with potential for hemolysis resulting from high shear stress or with potential for thrombosis caused by recirculation or stagnation. Quantitative velocity data are also needed for comparison with computational fluid dynamics (CFD) models of the VAD. In this study, experiments have again proven to be an essential complement to CFD for thorough investigations of the flow inside the pump.
Investigation of Materials for Blood‐Immersed Bearings in a Microaxial Blood Pump
Authors: Mahmood A.K. , Kerkhoffs W. , Schumacher O. , Reul H.
Published: March 2003

Abstract: Rotary blood pumps are gaining popularity among cardiothoracic surgeons. This article presents an in vitro investigation for choosing a suitable mechanical bearing system in a medium‐long term microaxial pump. Different metallic, polymeric, and ceramic components are introduced. Polymers displayed mechanical insufficiency for the application, whereas certain ceramics displayed an inconsistent pattern of failure. We are in search of a compromise in properties that would favor a durable material combination.
Recent Progress in Artificial Organ Research at Tohoku University
Authors: Yambe Tomoyuki , Yoshizawa Makoto , Tanaka Akira , Abe Ken‐ichi , Kawano Satoyuki , Matsuki Hidetoshi , Maruyama Shigenao , Amae Shintato , Wada Naoshi , Kamiyama Takamichi , Takagi Toshiyuki , Luo Run , Hayashi Junko , Kovalev Yuri A. , X.D.Sha Dan , Nanka Shunsuke , Saijo Yoshifumi , Mibiki Yoshiyuki , Shibata Mune‐ichi , Nitta Shin‐ichi
Published: March 2003

Abstract: Tohoku University has developed various artificial organs over the last 30 years. Pneumatic driven ventricular assist devices with a silicone ball valve have been designed by the flow visualization method, and clinical trials have been performed in Tohoku University Hospital. On the basis of these developments, a pneumatic driven total artificial heart has been developed and an animal experimental evaluation was conducted. The development of artificial organs in Tohoku University has now progressed to the totally implantable type using the transcutaneous energy transmission system with amorphous fibers for magnetic shielding. Examples of implantable systems include a vibrating flow pump for ventricular assist device, an artificial myocardium by the use of shape memory alloy with Peltier elements, and an artificial sphincter for patients with a stoma. An automatic control system for artificial organs had been developed for the ventricular assist devices including a rotary blood pump to avoid suction and to maintain left and right heart balance. Based upon the technology of automatic control algorithm, a new diagnostic tool for evaluating autonomic nerve function has been developed as a branch of artificial organ research and this new machine has been tested in Tohoku University Hospital. Tohoku University is following a variety of approaches aimed at innovation in artificial organs and medical engineering fields.
Miniature Vibrating Flow Blood Pump Using a Cross‐Slider Mechanism for External Shunt Catheter
Authors: Kawano S. , Isoyama T. , Kobayashi S. , Arai H. , Takiura K. , Saito I. , Chinzei T. , Abe Y. , Yambe T. , Nitta S. , Imachi K. , Hashimoto H.
Published: March 2003

Abstract: The prototype of the miniature vibrating flow pump (VFP) is developed for the external shunt catheter. The cross‐slider mechanism is applied to vibrate the tube, which causes the pumping effect. This mechanism results in successful development of the miniature and lightweight VFP. By the use of the prototype VFP, the experiment of the basic pump performance is made in detail based on the authorized procedure in the research field of fluids engineering. The typical H‐Q curve of VFP, which is the relationship between the pump head and the flow rate, can be obtained. This result suggests that the miniature VFP developed here can be expected to be used as the booster pump for the external shunt catheter in clinical applications.
Air Pollution and its Health Effects in Beijing
Authors: Xu Xiping , Wang Lihua , Niu Tianhua
Published: March 2003

ABSTRACT

The primary goals of this review were to summarize the epidemiological studies carried out in Beijing, China for assessing the health effects associated with both short‐term and long‐term exposures to air pollution. In these investigations, a time series study design was used to evaluate the health effects of short‐term air pollution exposures; cross‐sectional and longitudinal study designs were used to evaluate the health effects of long‐term air pollution exposures. Taken together, these epidemiological studies provide coherent evidence that short‐term exposures to air pollution are significantly associated with adverse reproductive outcomes such as preterm delivery and low infant weight, and excess daily morbidity and mortality, whereas long‐term exposures to air pollution are associated with increased respiratory symptoms or bronchitis in adults. Moreover, these investigations suggested a synergistic effect between air pollution and personal smoking. This review of environmental epidemiological studies in Beijing clearly indicates a link between human health and ecosystem health. Concrete measures in air pollution control must be taken to halt degradation of the earth’s ecosystems from a public health viewpoint.
Developing Ecosystem Health Indicators in Centro Habana: A Community‐based Approach
Authors: Spiegel Jerry M. , Bonet Mariano , Yassi Annalee , Molina Enrique , Concepcion Miriam , Mast Pedro
Published: March 2003

A set of interventions was undertaken between 1995 and 1999 to improve the quality of life and human health in Cayo Hueso, an inner city community in Central Havana. The municipality and community organizations contacted the agency responsible for public and environmental health in Cuba (INHEM) to evaluate whether these improvements were as effective and efficient as possible, so as to assist in planning further interventions in this and other communities. With the aid of international researchers, an effort was made to strengthen the community's capacity to apply an ecosystem health approach, adapting the analytical framework (DPSEEA: driving force–pressure–state–exposure–effects–action) developed for this purpose by the World Health Organization. A series of workshops and focus groups with community representatives and researchers was conducted in late 1999 and early 2000 to develop appropriate indicators for the analysis. Interventions were grouped into those relating to improved housing, the physical community infrastructure (e.g., water, sewage, street lights), and the socio‐cultural environment (e.g., programs for youths and seniors). The DPSEEA framework was embraced by the community and used to define indicators at the individual, household, and neighborhood levels; the community‐researcher team then collectively elaborated the methodology to obtain the needed information. Data collection is now underway with the process having triggered a series of new partnerships, including other communities (comparison groups) now eager to learn from the Cayo Hueso interventions. With the capacity to apply this approach strengthened, the community is preparing to use the results of the analyses to set new priorities and pursue longer‐term ecosystem health interventions.
Sustainability, Exceptionalism, and Exemptionalism
Authors: Cairns John
Published: March 2003

Sustainable use of the planet is based on the assumption that social evolution and changed human behavior can produce a sustainable society. This paradigm is vastly different from the notion that humans possess a common set of rigid, genetically specified behavioral predilections that are unlikely to be altered by circumstances. This manuscript examines two beliefs that are arguably root causes of the present human predicament.

Exceptionalists believe that some humans are vastly exceptional to most humans and, as a consequence, are entitled to a markedly disproportionate share of the planet's resources. In addition, humans are regarded as entitled to a vastly disproportionate share of the planet's resources compared with other species, for the same reason. Exemptionalists believe that human ingenuity, technology, and creativity free them from the iron laws of nature that limit and control other species. Both views constitute major obstacles to achieving sustainable use of the planet and require rigorous reexamination if sustainability is to be achieved.

“Brains exist because the distribution of resources necessary for survival and the hazards that threaten survival vary in space and time. There would be little need for a nervous system in an immobile organism or an organism that lived in regular and predictable surroundings … brains are buffers against environmental variability”.
Degrading Landscapes: Lessons from Palliative Care
Authors: Kristjanson Linda J. , Hobbs Richard J.
Published: March 2003

ABSTRACT Palliative care is the active total care of patients whose disease is not responsive to curative treatment. This paper presents a proposition that the principles of palliative care may offer a useful conceptual map that helps promote understanding of the degradation of landscapes and the decline of rural communities from an ecosystem management perspective. Landscape reorganization by humans for food and other production requires considerable inputs of energy and effort. Current trends of landscape degradation indicate that human endeavors have resulted in the loss of functional landscapes with a concurrent decline in ecosystem services. The argument can be made that, in cases where ecosystem degradation is extensive, the landscape may be terminally ill and in need of palliative care. The fundamental principles and components of palliative care are described and questions are posed regarding the extent to which palliative care principles and components challenge and extend current land management philosophies and practices.
Biodiversity, Endemism, Sense of Place, and Public Health: Inter‐relationships for Australian Inland Aquatic Systems
Authors: Horwitz Pierre , Lindsay Michael , O'Connor Moira
Published: March 2003

ABSTRACTNatural resource managers have articulated “health” narrowly and vaguely as the condition of the biophysical environment. It is too tempting for natural resource managers to take data generated from rapid assessment techniques of biophysical condition (like species richness) as surrogates for “biodiversity.” This paper takes the view that these common applications of the terms “health” and “biodiversity” obscure a meaningful search for the relationships between biodiversity, human health, and the socioeconomic well‐being of human communities. Using examples of landscapes and inland waters in Australia, we argue that the biodiversity of inland waters and human health are linked in at least two ways. Biodiversity, and its endemic features, contribute to a person's attachment to a particular place and become part of a person's identity. Loss, destruction, or change in a location has the potential to affect an individual's psychological well‐being, and challenge a community's identity and image of itself. Any inland waterway also has the potential to harbor biota that can directly affect the health of humans. We are exposed to this biota when we develop locations inappropriately, when we (mis)treat inland waters, or as a by‐product of other land and water developments. Our health may be compromised by attempts to control this biota. And our perceptions of a place may change dramatically according to the presence of these and other organisms, or according to our efforts at their control, as illustrated by cases involving wetlands, mosquitoes, and arboviruses. We conclude by arguing that the health of inland aquatic systems will be best articulated by intertwining biodiversity, endemism, perception of place, environmental (landscape) degradation, disease‐causing organisms, and management of the aquatic resource. The health sector and natural resource management agencies are encouraged to recognize the synergies between these issues in their policies and practices.
SUNCT Syndrome. Atypical Temporal Patterns
Authors: Pareja Juan A. , Joubert Jacques , Sjaastad Ottar
Published: March 2003

New clinical features of the SUNCT syndrome are described in a series of 3 men (mean age of 65 years, range 56 to 80). The mean age at the onset of symptoms was 55 years (range 39 to 77). Although in all patients the great majority of attacks were typical, on a few occasions unusual features of the painful attacks were either reported or witnessed by the investigators. We have classified these clinical phenomena as (1) low‐grade background pain or discomfort, and (2) relatively Long‐lasting attacks.

Neither neurological examination nor neuroimaging studies revealed structural lesions as responsible for the atypical features. The fact that these atypical attacks occurred in the usual symptomatic area and were accompanied by the usual ipsilateral autonomic signs, suggests that they are an integral part of the clinical picture of SUNCT. The possibility that another, concurrent headache was responsible for the unusual attacks is considered unlikely. These clinical phenomena should, accordingly, provisionally be considered as additional but rare clinical features of the SUNCT syndrome.
Self‐report of Cognition and Objective Test Performance in Posttraumatic Headache
Authors: Branca B. , Giordani B. , Lutz T. , Saper J. R.
Published: March 2003

The Cognitive Difficulties Scale, a self‐report measure of cognitive functioning, was administered to 111 consecutive adult referrals with posttraumatic head pain subsequent to mild to moderate head and/or cervical flexion‐extension injuries who were treated at a clinic specializing in head pain and neurologicel disorders. Factor analysis of the Cognitive Difficulties Scala yielded seven meaningful factors corresponding to the type of memory inefficiencies often associated with neurological dysfunction. Further analyses comparing the Cognitive Difficulties Scale factor scores to objective tests of mental status, memory, and depressed mood demonstrated limited relationships between specific Cognitive Difficulties Scale factor scores and these measures of cognitive performance and behavior. The Cognitive Difficulties Scale appears helpful in assisting this patient population with treatment planning and specific remediation tied to everyday situations.
Putative Neuroimmunological Mechanisms in Cluster Headache. An Integrated Hypothesis
Authors: Martelletti Paolo , Giacovazzo Mario
Published: March 2003

During the last decade, numerous studies have been carried out to explore the function of the immune system in cluster headache and the release of reciprocal informational molecules from pain‐sensitive structures. These neuroimmunological findings in cluster headache syndrome, although carefully considered, have varied from genetic aspects (HLA antigens) to functional activity of the immune system (NK cytotoxicity), and from study of the receptor expression of classical neurotransmitters of pain (5‐HT, histamine) on immunocompetent cells, to the study of cytokines with a potent pro‐inflammatory activity (interleukin‐1). Other aspects considered have ranged from the study of the effectiveness of substances possessing a well‐known activity on the immune system (prednisone, lithium carbonate) in shortening cluster attacks to the 5‐HT receptor expression changes observed on a peripheral substrata (monocytes) after the administration of sumatriptan.

Although this was an exciting area of pioneering research, we have always interpreted our findings cautiously.

In summary, we now believe that the neuroimmunological aspects of cluster headache can be proposed as an integrative model and that this immunological mechanism could improve our understanding of the pathogenic basis for this still obscure disease.
Electromyographical Ischemic Test and Intracellular and Extracellular Magnesium Concentration in Migraine and Tension‐Type Headache Patients
Authors: Mazzotta G. , Sarchielli P. , Alberti A. , Gallai V.
Published: March 2003

Headache has often been described in the hyperexcitability syndrome which recognizes an alteration of calcium and magnesium status in its etiopathogenesis. Moreover, in migraine patients magnesium has been shown to play an important role as a regulator of neuronal excitability and, therefore hypothetically, of headache. The present research involves a neurophysiological evaluation and magnesium status assessment of a group of headache patients. Nineteen patients (15 women and 4 men) with episodic tension‐type headache and 30 patients (27 women and 3 men) with migraine without aura were examined. An ischemic test was carried out on the right arm with electromyographic (EMG) recording of motor unit potential activity during the interictal period. The determination of extracellular (serum and saliva) and intracellular (red and mononuclear blood cells) magnesium was also performed. The EMG test was positive in 25 of 30 migraine patients and in 2 of 19 tension‐type headache patients. Between the two patient groups, there were no significant variations in the concentration of extracellular and white blood cell magnesium, while the red blood cell concentration of this mineral in the group of migraineurs was significantly reduced with respect to that in the group of tension‐type headache patients (P<0.05). The positive EMG test was significantly associated with a low concentration of red blood cell magnesium (P<0.0001). These results confirm previous findings by demonstrating different etiopathogenic mechanisms as the basis of migraine and tension‐type headache. Migraine seems to be related to an altered magnesium status, which manifests itself by a neuromuscular hyperexcitability and a reduced concentration in red blood cells.
Cervicogenic Headache: The Influence of Mental Load on Pain Level and EMG of Shoulder‐Neck and Facial Muscles
Authors: Bansevicius Dalius , Sjaastad Ottar
Published: March 2003

The relationship between pain and EMG levels was studied in 17 cervicogenic headache patients and 17 group‐matched healthy controls. All subjects performed a 1‐hour, complex, two‐choice, reaction time test. Every 10 minutes before, during, and also for 20 minutes after the test, they reported pain levels (using visual analogue scales) in the forehead, both temples, neck, and shoulders. Electromyographic activity, using superficial electrodes, was also recorded from the frontal, temporal, neck (splenius), and trapezius muscles. Maximal voluntary contractions were performed in all the muscles.

Increased pain levels before, during, and after the test were found on the symptomatic side in the temple, shoulder area, and neck in the patient group compared with nonsymptomatic side and controls (neck only compared with controls). Electromyographic amplitudes from the trapezius muscle on the symptomatic side were significantly higher before and during the test, compared with the nonsymptomatic side, but most markedly during the test. Pretest EMG amplitudes from the frontal muscle on the symptomatic side in patients were also significantly higher than those in controls, but the difference vanished during the test. There are indications that the temporal pain, is, the headache, is a referred pain.

These observations may point to a “muscular” involvement in the pathogenesis of cervicogenic headache, either primarily or, which seems more plausible, secondarily.
The Dyspeptic Syndrome in Migraine: Morphofunctional Evaluation on 53 Patients
Authors: Centonze Vincenzo , Polito Beatrice Maria , Cassiano Maria Antonietta , Doronzo Francesco , Ricchetti Giacinto , Portincasa Piero , Bassi Antonia , Albano Ottavio
Published: March 2003

The authors, in order to evaluate the important role of gastrointestinal dysfunction during the migraine attack, have studied 53 patients with migraine without aura during the asymptomatic stage between attacks.

Patients were examined functionally with a pH meter test of the gastroesophageal tract over 24 hours and morphologically with esophagogastroduodenoscopy. The results of this study point out that in a high percentage of patients with migraine, both evaluations are normal. The authors suggest the possibility of detecting, even hypothetically, an alteration of the common neurotransmitter substrate in the origin of migraine attacks and accompanying symptoms.
Two More Secondary Headaches Mimicking Chronic Paroxysmal Hemicrania. Is This the Exception or the Rule?
Authors: Gatzonis S. , Mitsikostas D.D. , Ilias A , Zournas C.H. , Papageorgiou C.
Published: March 2003

Two patients with headaches meeting the criteria of chronic paroxysmal hemicrania, as defined by the International Headache Society classification, are presented. Further investigations revealed parasellar pituitary microadenoma in the first patient and a maxillary cyst in the second. Surgical removal of the lesions resulted in complete relief from headaches. The clinical features of this rare syndrome are discussed and suggest that a more detailed laboratory study and clinical follow‐up is necessary in patients with chronic paroxysmal hemicrania.
High‐Dose Versus Low‐Dose Valproic Acid as a Prophylactic Medication
Authors: Taylor Kirk , Goldstein Jerome
Published: March 2003

Valproic acid has been shown to be effective in migraine prophylaxis. Its method of action is believed to be the inhibition of gamma‐aminobutyric acid transaminase. The therapeutic dose needed to prevent migraine headaches has been examined in several studies, yet the optimum dose has not been found. In this case report, valproic acid was given to a 24‐year‐old woman with chronic headaches at 1000 mg per day. Her headaches resolved for 2 months. She tapered herself off of the medication, and her headaches returned. She was restarted at 500 mg per day of valproic acid and again, her headaches resolved. She preferred being on the lower dose which she found as effective as the higher dose. Her case makes two interesting points. The first is that lower dosages of valproic acid may be as effective as higher ones in headache prophylaxis. The second is that more studies looking at dose ranges are needed to correlate effectiveness with daily requirements.