bluuebunny/crossref_metadata_2025 huggingface dataset:
Replacing Cardiopulmonary Bypass with Extracorporeal Membrane Oxygenation in Lung Transplantation Operations
Authors: Ko Wen‐Je , Chen Yih‐Sharng , Lee Yung‐Chie
Published: March 2003

Abstract: Cardiopulmonary bypass (CPB) is required in some lung transplantation (LTx) operations. However, it increases risks of bleeding and early graft dysfunction. We report our experiences of replacing CPB with heparin‐bound extracorporeal membrane oxygenation (ECMO) in LTx operations. If extracorporeal circulation was anticipated for the LTx operations, ECMO support was set up through the femoral venoarterial route after induction of anesthesia; then, LTx was done as usual. Five thousand units of heparin was injected intravenously during the femoral vessels cannulation, but no more was used during the first 24 h of ECMO support. If necessary, as in patients undergoing single LTx for end‐stage pulmonary hypertension, the ECMO support was directly extended into the postoperative period until reperfusion edema of the graft lung subsided. Twelve single LTxs and 3 bilateral sequential single LTxs were done under ECMO support. The advantages of using femoral ECMO rather than conventional CPB in LTx operations were the operative field was not disturbed by the bypass cannula, stable cardiopulmonary function and normothermia were maintained throughout the operations, there were less blood loss and transfusion requirements, and the left LTx was as easily performed as the right LTx. Red blood cell transfusion requirements during the operation and the first postoperative day were 4.4 ± 2.8 and 2.4 ± 2.0 U, respectively, in 10 adult patients undergoing uncomplicated single LTx with ECMO support, and 4.3 ± 1.3 and 1.5 ± 1.5 U in 8 adult patients undergoing single LTx without any extracorporeal circulatory support. The difference was not significant between the 2 groups (p = 0.53 and 0.32 by Mann‐Whitney U test). The ECMO did not increase blood transfusion requirements. In comparison, 13 U of red blood cell transfusion was required in 2 patients receiving single LTx under CPB support. The ECMO support made the postoperative critical care easier in recipients with graft lung edema. Except for 2 cases of primary graft failure, the ECMO could be weaned off and removed at bedside within a short period (27.9 ± 24.6 h, n = 13) with no major complications. In conclusion, the heparin‐bound femoral ECMO rather than CPB should be used for LTx operations unless concomitant cardiac repair is planned.
Long‐Term Expression of Highly Differentiated Functions by Isolated Porcine Hepatocytes Perfused in a Radial‐Flow Bioreactor
Authors: Morsiani Eugenio , Brogli Matteo , Galavotti Daniele , Bellini Tiziana , Ricci Daniele , Pazzi Paolo , Puviani Anna C.
Published: March 2003

Abstract: To overcome the limitations of standard hollow‐fiber module in ensuring efficient cell perfusion and long‐term expression of highly differentiated hepatocyte functions, we developed a novel bioreactor in which a three‐dimensional hepatocyte culture system was perfused in radial‐flow geometry. Isolated porcine hepatocytes were cultured for 2 weeks in recirculating serum‐free tissue culture medium, in which NH4Cl and lidocaine were repeatedly added, and ammonia removal, urea synthesis, monoethylglycinexylide (MEGX) production, albumin secretion, Po2, Pco2, O2 consumption, and pH were measured thereafter. During the whole duration of the study, ammonia removal was paralleled by urea production, while MEGX concentration was constantly increased. Our results indicated that hepatocytes remained differentiated and metabolically active throughout the duration of the study. The radial‐flow bioreactor allowed physiological contact between recirculating fluid and cells by equalizing the concentration of the perfusing components, including O2, throughout the module, suggesting a potential use of this configuration for extracorporeal liver support.
Development of a New Hollow Fiber Silicone Membrane Oxygenator: In Vitro Study
Authors: Kawahito Shinji , Maeda Tomohiro , Motomura Tadashi , Takano Tamaki , Nonaka Kenji , Linneweber Joerg , Mikami Minoru , Ichikawa Seiji , Kawamura Masaki , Glueck Julie , Sato Koshiro , Nosé Yukihiko
Published: March 2003

Abstract: An experimental silicone hollow fiber membrane oxygenator for long‐term extracorporeal membrane oxygenation (ECMO) was developed in our laboratory using an ultrathin silicone hollow fiber. However, the marginal gas transfer performances and a high‐pressure drop in some cases were demonstrated in the initial models. In order to improve performance the following features were incorporated in the most recent oxygenator model: increasing the fiber length and total surface area, decreasing the packing density, and modifying the flow distributor. The aim of this study was to evaluate the gas transfer performances and biocompatibility of this newly improved model with in vitro experiments. According to the established method in our laboratory, in vitro studies were performed using fresh bovine blood. Gas transfer performance tests were performed at a blood flow rate of 0.5 to 6 L/min and a V/Q ratio (V = gas flow rate, Q = blood flow rate) of 2 and 3. Hemolysis tests were performed at a blood flow rate of 1 and 5 L/min. Blood pressure drop was also measured. At a blood flow rate of 1 L/min and V/Q = 3, the O2 and CO2 gas transfer rates were 72.45 ± 1.24 and 39.87 ± 2.92 ml/min, respectively. At a blood flow rate of 2 L/min and V/Q = 3, the O2 and CO2 gas transfer rates were 128.83 ± 1.09 and 47.49 ± 5.11 ml/min. Clearly, these data were superior to those obtained with previous models. As for the pressure drop and hemolytic performance, remarkable improvements were also demonstrated. These data indicate that this newly improved oxygenator is superior to the previous model and may be clinically acceptable for long‐term ECMO application.
Immunoglobulin Treatment Versus Plasma Exchange in Patients with Chronic Moderate to Severe Myasthenia Gravis
Authors: Rønager Jesper , Ravnborg Mads , Hermansen Ingrid , Vorstrup Sissel
Published: March 2003

Abstract: The purpose of this study was to compare the efficacy of high‐dose intravenous immunoglobulin (IVIG) treatment with plasma exchange in patients suffering from moderate to severe myasthenia gravis (MG) in a stable phase. There are no controlled studies comparing IVIG with plasma exchange in patients who despite immunosuppressive treatment have persistent incapacitating MG symptoms. This was a controlled crossover study. Twelve patients with generalized moderate to severe MG on immunosuppressive treatment for at least 12 months were included. The patients were evaluated clinically using a quantified MG clinical score (QMGS) before and at follow‐up visits after each treatment. One week after the treatments, the patients who received plasma exchange treatment showed a significant improvement in QMGS compared to baseline but although some improvement was seen after IVIG this did not reach statistical significance. Four weeks after both plasma exchange and IVIG treatments, there was a significant improvement in QMGS compared to baseline. One week and 4 weeks after treatment, no significant difference between the 2 treatments was found. Both treatments have a clinically significant effect 4 weeks out in patients with chronic MG, but the improvement has a more rapid onset after plasma exchange than after IVIG.
Risk of Bacterial Infection in Patients Under Intravenous Iron Therapy: Dose Versus Length of Treatment
Authors: Canziani Maria Eugênia F. , Yumiya Suely T. , Rangel Erika B. , Manfredi Silvia R. , Neto Miguel Cendoroglo , Draibe Sergio A.
Published: March 2003

Abstract: Some studies have suggested that intravenous iron therapy may be associated with an increased risk of infection. We analyzed the incidence of bacterial infection in 111 hemodialysis patients. Group 1 (n = 39, transferrin saturation <20%) received 10 doses of 100 mg of intravenous iron saccharate, 3 doses per week (28 treatment days); Group 2 (n = 13, transferrin saturation <20%) received 20 doses, 3 doses per week (70 treatment days); and Group 3 (n = 59, transferrin saturation 20–50%) received 10 doses, 1 dose per week (70 treatment days). The follow‐up was 150 days for all groups, and all infectious episodes were recorded. Pulmonary infection was the most frequent event observed in all of the groups. In an incidence‐density analysis, Group 2, which received a total of 20 doses, presented a significantly higher incidence of infection than Group 3, which received only 10 doses over the same period (0.13 versus 0.06 infections per patient per month, p = 0.04). No difference was observed between Groups 1 and 2 suggesting that the risk of infection during iron therapy is dose dependent rather than time length dependent.
Mechanical Behavior and Stability of the Internal Membrane of the InCor Ventricular Assist Device
Authors: Da Costa Teixeira Pedro Baroni , Gonçalves Paulo Batista , Cestari Idágene A. , Leirner Adolfo A. , Pamplona Djenane
Published: March 2003

Abstract: This paper describes and analyzes the mechanical behavior of the internal membrane of the InCor VAD (Heart Institute [InCor], University of São Paulo, Brazil), applying the knowledge and tools of structural engineering analysis. This membrane plays an important role in the operation of the ventricular assist device (VAD) because it separates the blood chamber from the pneumatic one, transmitting the pneumatic load to the blood, thus making the desired blood flow possible. The loading repeats itself every time the VAD beats. Therefore the performance, reliability, and durability of the membrane are critical for the performance of the VAD. The mathematical model is based on the large deflection theory of thin shells and on the finite element method. The snap‐through instability phenomenon, which is responsible for transmission of the pneumatic load to the blood, was observed in the membrane both when modeled mathematically and experimentally. Principal stresses and strain distributions were obtained with this model at certain load levels along the pre‐ and postbuckling paths.
Continuous Renal Replacement Therapy and Plasma Exchange in Newborns and Infants
Authors: Ponikvar Rafael , Kandus Aljoša , Urbančič Alenka , Kornhauser Andreja Gostiša , Primožič Janez , Ponikvar Jadranka Buturović
Published: March 2003

Abstract: The objective of our study was to present our experience in the treatment of small children with continuous renal replacement therapy (CRRT) and plasma exchange (PE). From March 1986 to April 2000, 21 critically ill children (14 newborns and 7 infants) with acute renal failure (ARF) and multiple organ failure were treated with CRRT and PE. In the newborn group, there were 8 males and 6 females, age 15.7 ± 11.7 days, with body weights of 3,348 ± 585 g. In the infant group, there were 4 males and 3 females, age 118 ± 67 days, with body weights 5,186 ± 734 g. The indications for the beginning of CRRT and/or PE were ARF with anuria and hyperhydration (17 patients), azotemia and anuria (1 patient), hemolytic uremic syndrome (1 patient), and hyperammonemia (2 patients). In all patients, peritoneal dialysis was considered inappropriate. PE and CRRT monitors were used, double lumen 5 Fr and 7 Fr hemodialysis catheters were the vascular access, low dose heparin and prostacyclin were anticoagulants, and lactate or bicarbonate buffered replacement solutions were used predilutionally. Side events were clotting within the extracorporeal circuit, catheter malfunction, serious hypotension (6 patients), and pulmonary edema (1 patient). Ten of 21 patients (47.6%) recovered renal function and 9 of 21 patients (42.9%) survived. Survivors had fewer failing organs (3.6 ± 0.5) than nonsurvivors (4.8 ± 0.9) (p = 0.0008). Pump driven CRRT and PE were feasible, efficient, and safe procedures in newborns and infants. Without CRRT, it is uncertain whether any of our patients would have the chance to survive.
Quo vadis Dialysis Membrane?
Authors: Vienken Joerg , Bowry Sudhir
Published: March 2003

Abstract: The development of dialysis membranes is closely related to the development of dialysis as a routine therapy for patients with kidney failure. Without having membranes and dialyzers available as commodity products, the treatment of more than 1 million uremic patients worldwide would be impossible. Several transition periods can be identified: a change in membrane geometry from flat sheet to capillaries, a shift in market appreciation from cellulose to synthetic polymers, and from low‐flux to high‐flux dialyzers. This shift is supported by the notion that convective therapies using high‐flux membranes allow the removal of large‐molecular‐weight solutes. From a historical background, three eras of perception can be identified for both membrane and dialysis development. First, the period of survival when nephrologists had to focus on techniques for blood access and availability of membranes. Second, the period of issues dedicated to rather specific features of membranes and dialysis therapy such as dose of dialysis, reuse, sterilization, and membrane biocompatibility. And third, the period of quality tops this sequence with a complicated approach: the principal area of interest from the medical community has switched to issues such as quality of life, morbidity, mortality, therapy standards, and cost‐effectiveness. New membrane developments should focus on this situation.
Chronic Heart Failure Model in Rabbits Based on the Concept of the Bifurcation/Trifurcation Coronary Artery Branching Pattern
Authors: Lee Byeong Han , Kim Woong Han , Choi Mi Jin , Rho Joon Ryang , Kim Won Gon
Published: March 2003

Abstract: The aim of this study was to develop a reliable chronic heart failure model by coronary artery ligation in the rabbit on the basis of the new concept of the bifurcation/trifurcation classification system of the epicardial branching pattern of the left coronary artery (LCA). New Zealand White rabbits (n = 37) were divided into 3 experimental groups: a posterolateral division of the bifurcation pattern of the LCA was ligated at the 75% level from the apex along the course of the division (B75 group, n = 15); a lateral division of the trifurcation pattern at the 75% level (T75 group, n = 11); and a posterolateral division of the bifurcation pattern at the 50% level (B50 group, n = 11). The infarct size and the lung and liver water content were determined at 4 weeks following ligation. The Q or QS wave on electrocardiogram (ECG) and the left ventricular (LV) dimensions (LVIDs and LVIDd), fractional shortening (FS), and mitral E‐point to septal separation on ultrasonography were assessed at 10 min and at preligation and at 1, 2, and 4 weeks following ligation. The B75 group showed higher mortality (46.7%) than the T75 and B50 groups. The mean infarct size in the B75 group was 22.55 ± 5.34% which was significantly larger than in the B50 (13.84 ± 5.46%) and T75 (12.90 ± 2.67%) groups (p < 0.001). All 3 groups had significantly greater Q or QS wave amplitudes on ECG at 1, 2, and 4 weeks than at 10 min after ligation. At 1 and 2 weeks after ligation, LVIDd, LVIDs, and FS showed significant dfferences in the B75 group as compared with the other groups. The level of ligation of the LCA for the development of a reliable chronic heart failure model in the rabbit is recommended to be 50% from the apex along the course of the posterolateral division in the bifurcation pattern and 75% from the apex along the course of the lateral division in the trifurcation pattern.
Enhanced Intra‐Aortic Balloon Pump: Markedly Improved Systemic Hemodynamics and Cardiac Function in Canines with Severe, Acute Left Ventricular Failure
Authors: Bian Xiaoming , Downey H. Fred
Published: March 2003

Abstract: Intra‐aortic balloon pumps (IABPs) cannot sustain hemodynamics if the left heart is severely injured. An enhanced IABP was evaluated in 6 anesthetized dogs with acute stenosis of the left anterior descending coronary artery, regional left ventricular (LV) stunning, and global LV dysfunction. An IABP balloon was inserted into the descending aorta and an external chamber containing another IABP balloon was connected to the aorta through a catheter inserted into the left subclavian artery. This emulated the enhanced IABP with a conduit from its external chamber passing axially through an internal IABP balloon. Compared to IABP, enhanced IABP improved hemodynamics and LV function in all conditions. During severe LV dysfunction and circulatory failure, IABP failed to augment diastolic aortic pressure or improve coronary and carotid flows. Enhanced IABP augmented diastolic pressure from 32 ± 3 mm Hg to 87 ± 2 mm Hg and increased coronary and carotid flows. Enhanced IABP may be a lifesaving device for patients with severe LV failure.
A Stimulator for Functional Activation of Denervated Muscles
Authors: Hofer Christian , Mayr Winfried , Stöhr Hans , Unger Ewald , Kern Helmut
Published: March 2003

Abstract: In recent years various studies proved that electrical stimulation can improve contractile capability and restore muscle function in long‐term denervated degenerated muscles. The low excitability of the muscle cells at the initial stage of training and surrounding connective tissue, acting as an electrical shunt, require special stimulation parameters. Until now, no appropriate devices (stimulators) are commercially available. Therefore, we were forced to design our own stimulators. The control unit of the stimulators is based on a microprocessor for maximum flexibility regarding the generation of the parameters such as pulse amplitudes, pulse width, frequency, stimulation times, ramps, and so on. In addition, the microprocessor design allows recording of compliance data such as stimulation date, time, duration, and used programs. The constant voltage output stage of the stimulator is able to generate biphasic charge balanced stimulation impulses with a pulse width of 1 to 300 ms, voltage amplitudes up to ±80 V (160 VPP), and stimulation currents up to 250 mA. To prevent direct current due to inexact charge compensation, the electrode outputs are decoupled capacitively. Simultaneous 2 channel stimulation with independent intensity levels is possible. The stimulators are programmed using a notebook or a personal digital assistant via infrared serial interface. This concept guarantees the application of correct stimulation parameters because the patient has only access to parameters that are preprogrammed for him in the outpatient clinic. For the home based training, access is limited to variation of intensity within preprogrammed limits. For safety reasons, the portable unit is powered by an internal rechargeable battery. High efficiency switched voltage regulators are used to provide the different required voltage levels while ensuring an acceptable operating time of the stimulator.
Functional Analysis of the Tissue‐Engineered Stomach Wall
Authors: Hori Yoshio , Nakamura Tatsuo , Kimura Dai , Kaino Kenji , Kurokawa Yoshimochi , Satomi Susumu , Shimizu Yasuhiko
Published: March 2003

Abstract: We have established a method for in situ tissue engineering of the stomach in a canine model using an acellular collagen scaffold graft. The current study was conducted to evaluate the functional aspects of the tissue‐engineered stomach wall. The anterior wall of the stomach in beagle dogs was replaced with a collagen sponge scaffold measuring 4 × 4 cm. At 16 weeks after implantation, the animals were sacrificed and the stomach specimens were evaluated immunohistochemically and physiologically. Regeneration of the proton pump and thin muscle layer, which are essential for mechanical and chemical digestion by the stomach, was observed in the tissue‐engineered gastric tissue. However, acetylcholine‐induced contraction was not observed in the tissue‐engineered stomach wall. Although there is still room for improvement, the tissue‐engineered stomach wall had a highly organized structure, and it is anticipated that this approach could eventually become an alternative for stomach reconstruction after gastrectomy.
Biomedical Properties of Nanofabricated Fluorinated Polyimide Surface
Authors: Nagaoka Shoji , Ashiba Keisuke , Kawakami Hiroyoshi
Published: March 2003

Abstract: Cell adhesion, proliferation, and their orientation on the surface of fluorinated polyimide, 6FDA‐6FAP, which was fabricated by curing treatment and the rubbing method, were investigated using a continuous cell line of human epithelial cells (adherent HeLa). The surface free energy of the fabricated 6FDA‐6FAP was analyzed by the contact angle measurement and the topographic change of the surface was observed using atomic force microscopy. These properties were changed drastically by the treatment, and it was found that the adhesion and proliferation of the cells increased with the curing temperature. The noticeable finding was that the cells on the rubbed 6FDA‐6FAP surface were modulated and aligned along with the rubbing direction, where nano‐ordered grooves were formed, while the cells proliferated randomly on the unrubbed surface without such a nano‐ordered structure.
Centrifugal Blood Pumps for Various Clinical Needs
Authors: Ichikawa Seiji , Nosé Yukihiko
Published: March 2003

Abstract: During the past 10 years, different types of blood pumps were developed to address various clinical needs. The Nikkiso centrifugal blood pump was developed for cardiopulmonary bypass application. This blood pump has been widely used in Japan in more than 20% of the cardiopulmonary bypass procedures. The Kyocera C1E3 Gryo pump was developed for short‐term circulatory assistance and extracorporeal membrane oxygenation application for up to 2 weeks. This blood pump has been clinically used for up to 28 days without any blood clot formation. Through Phase I of the Japanese government New Energy and Industrial Technology Development Organization (NEDO) program, a chronically implanted centrifugal pump for left ventricular assistance was developed. This pump has already demonstrated its effectiveness, safety, and durability as a 2 year blood pump through in vitro and in vivo experiments. Currently, it is in the process of being converted from an experimental to a clinical device. Through Phase II of the NEDO program, a permanently implantable biventricular assist centrifugal blood pump system is under development. It has demonstrated that the previously mentioned left ventricular assist device blood pump is easily converted into a right ventricular assist pump by simply adding a spacer between the pump and the actuator. This communication discusses the historical development strategies for centrifugal blood pumps and their current status for different clinical needs.
Delivery of a Growth Factor Fusion Protein Having Collagen‐Binding Activity to Wound Tissues
Authors: Ishikawa Tetsuya , Terai Hiroshi , Yamamoto Takashi , Harada Kazumichi , Kitajima Takashi
Published: March 2003

Abstract: Recently, we established a collagen‐binding growth factor consisting of epidermal growth factor and the fibronectin collagen‐binding domain (FNCBD‐EGF). FNCBD‐EGF is a biologically active fusion protein that could stably bind to collagen materials, and exert its growth factor activity even after collagen binding. In this study, we investigated the concept that FNCBD moiety with high collagen affinity may enhance the effective local concentration of EGF at the site of administration in the following tissues: skin wounds, catheter‐injured arteries, and hind limb muscles. In an animal model of impaired wound healing, application of FNCBD‐EGF in combination with collagen gel induced granulation tissue formation in the wounds due to its sustained retention. In the injured artery, infused FNCBD‐EGF remained bound to collagen exposed on the injured tissues even after blood circulation was restored. Injection of the fusion protein into the hind limbs revealed that our delivery system was effective for direct administration to muscular tissue.
Development of a Polymer Bileaflet Valve to Realize a Low‐Cost Pulsatile Blood Pump
Authors: Iwasaki Kiyotaka , Umezu Mitsuo , Iijima Kazuo , Inoue Akira , Imachi Kou , Ye Chun Xiu
Published: March 2003

Abstract: The final goal of this study is to realize a low‐cost pulsatile blood pump especially for patients with acute heart failure or postoperative low cardiac output syndrome. In support of the pump, two types of polymer bileaflet valves with different configuration of the valve seats were developed. Influence of the leaflet thickness on the hydrodynamics of the prototype was preliminarily investigated among 70 μm, 100 μm, and 150 μm. As to the valves with the thinner leaflets, buckling of the leaflets was observed, which induced a large amount of regurgitation at valve closure. However, by thickening the leaflet to 150 μm, the mean flow of the prototype and the second model could be successfully comparable to the Medtronic‐Hall valve. Moreover, accelerated fatigue tests showed that reinforcement of the valve seat with the additional spokes in the second model extended the durability by four times as compared with the prototype, equivalent to an in vivo duration of over one month.
Blood Compatible Design of a Pulsatile Blood Pump Using Computational Fluid Dynamics and Computer‐Aided Design and Manufacturing Technology
Authors: Okamoto Eiji , Hashimoto Takuya , Inoue Taku , Mitamura Yoshinori
Published: March 2003

Abstract: Thrombus formation is a critical issue when designing a long‐term implantable left ventricular assist system (LVAS). Fluid dynamic characteristics of blood flow are one of the main factors that cause thrombus formation. In this study, we optimized the fluid dynamics of a sac blood pump in our LVAS to ensure minimization of shear‐related blood damage that could lead to thrombus formation. A pump housing and a sac chamber were designed with computer‐aided design (CAD) software, and fluid dynamics were estimated by computational fluid dynamic (CFD) analysis. We adopted distribution of CFD results for qualitative evaluation, and we also tried to estimate normalized index of hemolysis (NIH) from the results of CFD analysis as a quantitative index of optimization for geometry of the blood pump chamber. A prototype model of the optimized blood pump was made using a three‐axis computer machine tool by whittling pieces of nonfoamed polyurethane. Shear stress and theoretical NIH in the redesigned model were lower than those in the first model. Area of flow stagnation that was observed in the first model was not seen in the redesigned model. The results demonstrate that application of CAD/CAM technology to design an artificial heart contributes to optimizing a blood pump chamber for the purpose of reducing thrombus formation.
Development of an Implantable High‐Energy and Compact Battery System for Artificial Heart
Authors: Okamoto E. , Inoue T. , Watanabe K. , Hashimoto T. , Iwazawa E. , Abe Y. , Chinzei T. , Isoyama T. , Kobayashi S. , Saito I. , Sato F. , Matsuki H. , Imachi K. , Mitamura Y.
Published: March 2003

Abstract: The purpose of this study was to demonstrate the feasibility of the use of an implantable, high‐energy, and compact battery system for an undulation pump total artificial heart (UPTAH). The implantable battery system tested consists of six lithium‐ion batteries in series, a charge unit, and a charge/discharge control unit. A lithium‐ion battery is currently the best energy‐storage device because it has more energy density, a better life cycle, and a smaller temperature rise than those of other secondary batteries. The performance of the implantable battery system was evaluated in an in vitro experiment using an electric load that simulated the UPTAH. Also, sufficiently reliable operation of a system for supplying energy to a UPTAH consisting of a transcutaneous energy transmission system (TETS) and an implantable battery system was confirmed in three experiments using goats. The results of the in vitro and in vivo experiments showed that the implantable battery system supplied sufficient current to the UPTAH for maintenance of physiological conditions in the goat with maximum rise in temperature to less than 43°C.
Does the World Trade Organization Care about Ecosystem Health? The Case of Trade in Agricultural Products
Authors: Buckingham Donald E.
Published: March 2003

ABSTRACT

We now live under a comprehensive international trading system which affects what we eat, wear, buy, and produce. As of January 1995, the General Agreement on Tariffs and Trade 1947 (GATT 1947) was replaced by the World Trade Organization Agreement (WTOA) which sets out rules affecting practically all trade in goods and services worldwide.

The implications for trade in agricultural goods are enormous. Today, not only are rules concerning trade in goods generally applicable to trade in agricultural goods, but new rules specific to trade in such products are set out in the WTOA’s Agreement on Agriculture. The WTOA promises to limit national agricultural policies which impede international trade in agricultural products. The new WTOA rules should increase efficiency of and decrease friction arising in trade in agricultural products. These developments represent truly positive economic and political outcomes.

But what will be the environmental effects of changes in trade flows facilitated by WTOA rules and institutions? How will the new rules affect ecosystem health? The truth is that the worlds of trade law and ecosystem health are light‐years apart. Advocates for free trade and those for the environment often distrust each other and think that the interests of one can be advanced only through the sacrifice by the other. The first part of this article traces some of the reasons for the evolution of this seemingly zero‐sum game. The second section of the article examines the historical development and current treatment of environmental measures under the WTOA.

The agricultural sector is then highlighted as a microcosm of how the new WTOA rules will produce environmental effects which positively, although perhaps unintentionally, affect agroecosystems. The article concludes with speculation as to whether it is not now time to reorient the acrimonious trade/environment debate to one which is less adversarial and more focused on achieving ecosystem health while continuing to improve international market access and trade relations.
Animal Indicators of Adverse Effects Associated with Air Pollution
Authors: Saldiva Paulo Hilário Nascimento , Böhm György Miklós
Published: March 2003

ABSTRACT

The possibilities for using animal indicators for air pollution studies are reviewed. Three major problems are discussed: bioconcentration of trace elements, alterations of physiological parameters, and genotoxic effects. Sentinel species seem to be useful bioaccumulators of environmental trace elements and may be the first choice for detecting pollutants whenever there is a high affinity between the pollutant and a specific animal tissue. Also metallothionein levels of different invertebrate organisms has been shown to be a very sensitive indicator of metal pollution. The assessment of the pulmonary functions, the regulation of airway caliber, and mucociliary clearance in animals exposed to polluted urban air is presented and their advantages for estimating physiological damages induced by air pollution are advocated. Considering the availability of easy techniques to evaluate genetic damage, sentinel species have proven to be an attractive approach to detect genotoxic effects in all kinds of environmental pollution. A continuous effort of the scientific community is necessary to establish the importance of animal sentinel studies on the process of evaluating risks and formulating regulatory procedures.
Population Health Issues in the Management of Air Quality
Authors: Burnett Richard T. , Jessiman Barry , Stieb David , Krewski Daniel
Published: March 2003

ABSTRACTEpidemiological studies conducted in a number of countries have consistently demonstrated associations between concentrations of ambient air pollution and adverse health outcomes, including premature mortality, cardiorespiratory hospitalizations, emergency department visits for respiratory diseases, asthma attacks, respiratory symptoms, and restricted activity. These associations have prompted regulatory agencies in several countries, including Canada, to either revise current air quality standards or establish new ambient guidelines. In this article, recent epidemiological research in Canada is briefly reviewed in relation to the establishment of PM10and PM2.5national air quality objectives. Economic approaches to evaluating costs and health benefits of controlling air pollutants are discussed, and their use illustrated in evaluating the consequences of reducing the sulphur content of gasoline. Ongoing epidemiological research on the health effects of air pollution is outlined, and strategies for evaluating and managing the health risks of air pollution examined.
Sustainable Development: Lessons from the Paradox of Enrichment
Authors: Choi Jae S. , Pattent Bernard C.
Published: March 2003

With the current struggle to “sustainably” exploit our biosphere, the “paradox of enrichment” remains an issue that is just as relevant today as it was when it was first formalized by Rosenzweig in 1971. This paradox is relevant because it predicts that attempts to sustain a population by making its food supply more abundant (e.g., by nutrient enrichment) may actually have the reverse (paradoxical) effect of destabilizing the network. Originally, this paradox was based upon studies of “reasonable,” but quite simple, predator‐prey models. Here, we attempt a more “realistic” revision of the paradox that explicitly accounts for the embedded nature of the human system in a complexly interwoven set of hierarchical (spatial, temporal, and organizational) relations with the rest of the ecosphere‐a relationship whose exploitative nature continues to grow in intensity and extent. This revision is attempted with the aid of a combined thermodynamic and network approach. The result is that a scaledependent asymmetry in the action of the second law of thermodynamics is shown‐an asymmetry that results in the creation of two antagonistic propensities: local order and local disorder. The point of balance between these two propensities is empirically measurable and represents a balance between processes and constraints internal (growth and development) and external (interactive and perturbing influences) to a system‐a balance that may be called the most “adaptive” state (after Conrad 1983). The use of such an index of this balance is demonstrated and it is used to clarify the relevance of the paradox to more complexly organized systems. As a consequence, we conclude that the concept of “sustainable exploitation and growth” is an oxymoron.
What on Earth is Life? An Ecological View
Authors: Rowe Stan
Published: March 2003

Although definitions of the meaning of “life” are various, none recognizes the importance of context. A partial explanation of the attribution of “life” only to organisms is the fact that the ecosphere–the context and source of organisms–has, until recently, been invisible. Further, the metaphorical nature of abstract language has conflated “organisms” and “life.” But just as the living parts of an organism depend on the vitality of the whole, so living organisms depend on the energetics of planet Earth from which they evolved and by which they are maintained. From an ecological viewpoint, planet Earth, the inclusive supra‐organic ecosphere, is a logical metaphor for “life.”
Migraine as a Cause of Sudden Hearing Loss
Authors: Viirre Erik S. , Baloh Robert W.
Published: March 2003

Sudden heating loss is common, but unexplained in many cases. Although usually attributed to a viral infection of the inner ear in mort patients, the abrupt onset of the hearing loss in many patients argues against a viral etiology. We present 13 cases of unexplained sudden healing loss who meet the diagnostic criteria for migraine. All had the sudden onset of hearing loss and other neurologic phenomena that could be attributed to vasospasm, including vertigo, amaurosis fugax, hemiplegia, facial pain, chest pain, and visual aura. We suggest that vasospasm of the cochlear vasculature was the cause of the sudden hearing loss in these patients. A personal and family history of migraine should be sought in patient; with sudden heating loss and when found, a trial of antispas modic agents should be considered.
β‐Endorphin in Plasma and Monocytes in Juvenile Headache
Authors: Battistella P.A. , Bordin A. , Cernetti R. , Broetto S. , Corrá S. , Piva E. , Plebani M.
Published: March 2003

Interictal serum levels of serotonin and plasma and mononuclear cell concentrations of β‐endorphin were measured in 20 juvenile patients (13 suffering from migraine without aura and 7 from episodic tension‐type headache) before and after 3 months of L‐5‐hydroxytryptophan treatment (5 mg/ kg/day) and compared with a control group of 17 headache‐free healthy subjects.

While no significant differences in serum serotonin levels emerged between the three groups (migraine 104.6 ± 26 μg/ L, tension‐type headache 90.7 ± 26.2 μg/L, controls 96 ± 32.9 μg/L), significantly lower plasma and mononuclear cell concentrations of β‐endorphin were found in both patient groups by comparison with the healthy controls (β‐endorphin in plasma: migraine sufferers 16.2 ± 4.2 pmol/L [P<0.05], tension‐type headache subjects 14.5 ± 1.7 pmol/L [P<0.001] vs controls 21.3 ± 4.6 pmol/L and respectively, ß‐endorphin in mononuclear cells: migraine sufferers 110.5 ± 16.4 pmol/106 GB/L [P<0.001], tension‐type headache subjects 142.3 ± 22.7 pmol/106 GB/L [P<0.001] vs controls 359.3 ± 31.6 pmol/106 GB/L). No differences emerged between the two clinical forms of headache for the plasma and mononuclear cell concentrations of β‐endorphin.

After L‐5‐hydroxytryptophan treatment, serum serotonin and both plasma and mononuclear cell βI‐endorphin levels tended to be higher, though not significantly so, than prior to treatment, and the clinical score (frequency x intensity of headache attacks) was significantly lower in both headache groups than at the baseline.

This study supports the theory that opiate analgesic system function is abnormally low in juvenile primary headache as in adults, and confirms that administering serotoninergic precursor drugs increases β‐endorphin, even in the peripheral blood, and may favorably affect clinical symptoms.
Specificity of IHS Criteria in Childhood Headache
Authors: Seshia Shashi S.
Published: March 2003

We prospectively assessed the relative specificity of the International Headache Society (IHS) criteria in 30 children referred to a pediatric neurologist. An important cause of headache, including raised intrecranial pressure with slit ventricle syndrome, would have been missed in 4 children if one had relied on IHS criteria alone. Specific revisions have been proposed to minimize misclassification and further enhance the relevance of the IHS document for children.
Headache‐Free Controls? Evidence of Headaches in Individuals Who Deny Having Headaches During Diagnostic Screening
Authors: Wittrock David A. , Ficek Shelley K. , Cook Tricia M.
Published: March 2003

In the course of two studies investigating whether individuals with recurrent tension headache differ from headache‐free controls in the frequency and appraisal of stressful life events, subjects were asked to complete a headache diary for I week. Subjects in the headache‐free control group were screened twice and reported having infrequent headaches (two or less per month). However, 13 of 38 control subjects reported multiple headache days on their headache diaries. These subjects also reported a greater frequency of stressful events and a greater stress impact score. These results suggest that a careful screening of control subjects may be necessary in studies theft examine differences between subjects with recurrent headache and headache‐free controls. There is also some evidence that the inclusion of these subjects in a control group may bias the sample, making it less likely to find between‐group differences.
Alternatives in Drug Treatment of Chronic Paroxysmal Hemicrania
Authors: Evers Stefan , Husstedt Ingo‐Wilhelm
Published: March 2003

Indomethacin is the drug of first choice in chronic paroxysmal hemicrania with clear relief of pain as a diagnostic criterion. In a few cases, indomethacin is not tolerated because of side effects. Therefore, the efficacy of carbamazepine, verapamil. sumatriptan. acetylsalicylic acid, and oxygen as drugs in the prophylactic or acute treatment of chronic paroxysmal hemicrania was studied in a prospective open trial with 10 patients suffering from chronic paroxysmal hemicrania. The trial results, in accordance with a review of the literature. suggest that acetylsalicylic acid (and probably naproxen and diclofenac) and verapamil are the most effective drugs of second choice in chronic paroxysmal hemicrania. The efficacy of sumatriptan in this condition needs still to be clarified. although there is evidence for partial efficacy. Carbamazepine and oxygen did not show any significant influence on chronic paroxysmal hemicrania.
Cluster Headache in Two Sisters. Pupillary Response to Phenylephrine and Tyramine
Authors: Havelius UIf , Milos Peter , Hindfelt Bengt
Published: March 2003

Two sisters with cluster headache were studied with respect to the pupillary responses to instillation into the conjunctival sac of a single drop of a 1% solution of phenylephrine and a 2% solution of tyramine. The changes in pupillary diameters were documented by photographic pupillometry prior to and at 15, 30, 60, and 90 minutes after the instillations.

Of the two sisters, one (case A) was examined during a symptom‐free interval, when she had been free from cluster headache attacks for 2 1/2 years. When the cluster headaches recurred, retesting was performed. The other sister (case B) had been free from cluster headaches for 9 years, when she was examined.

The findings indicate hypofunction within the postganglionic sympathetic nerve fibers during a cluster headache period. The hypofunction is bilateral, and thus, can not be a consequence of the unilateral cluster headache attacks. During remissions, tyramine induces a marked mydriasis, particularly on the symptomatic side, tentatively indicating an excessive release of stored monoamines.
Ciliospinal Reflex Response in Cluster Headache
Authors: Havelius Uif , Heuck Martin , Milos Peter , Hindfelt Bengt
Published: March 2003

The ciliospinal reflex response is mainly mediated by second‐ and third‐order sympathetic nerves to the dilatator muscle of the iris. As the pupillary response to various pharmacological agents indicates a sympathetic dysfunction in patients with cluster headache, the ciliospinal reflex was studied in 25 patients. Five of these patients with cluster headache exhibited a Horner‐like syndrome (miosis, ptosis) on the symptomatic side. The pupillary responses to phenylephrine and tyramine showed that the Horner‐like syndrome was due to postganglionic sympathetic nerve dysfunction. Their ciliospinal reflex response on the symptomatic side was significantly less than in controls and in other patients with cluster headache, lacking a Horner‐like syndrome. This also applied to the nonsymptomatic side compared to the majority of cluster headache patients without any clinical evidence of sympathetic nerve dysfunction.

These findings seem to delineate those patients with a Horner‐like syndrome as a subgroup, distinctly separated from the majority of cluster headache patients. Furthermore, the findings indicate that the Horner‐like syndrome is not a consequence of repeated attacks of headache over many years, but is a manifestation of bilateral cephalic sympathetic dysfunction being more marked on the symptomatic side.

In 18 (72%) of our 25 patients, an asymmetric and lower ciliospinal reflex response on the symptomatic side was seen. In 3 (12%) patients, there was no difference in the response. In 4 patients (16%), the incorrect side was indicated by an asymmetric reflex response. Two of these patients (8%) had suffered from cluster headache on alternating sides.

In summary, the findings support the concept that dysfunction of the sympathetic nervous system, whether peripheral or central, is involved in the pathophysiology of cluster headache.
Effects of Headaches During Neuropsychological Testing of Mild Head Injury Patients
Authors: Tsushima William T. , Newbill William
Published: March 2003

The Luria‐Nebraska Neuropsychological Battery (LNNB and the Minnesota Multiphasic Personality Inventory (MMPI) were administered to 37 mild head injury patients whose headache activity was rated at the time of testing A one‐way analysis of variance (ANOVA) compared each of the 11 LNNB scores of patients with severe headache, mild headache and no headache. The results revealed no significant differences on varied neuropsychological tests between the three headache groups. Similar analyses of the 13 MMPI scores also indicated no significant differences between the three headache groups across various psychoemotional measures. The results are consistent with previous research and suggest that headaches do not affect the performance of mild head injury patients on varied neuropsychological tests requiring concentration and immediate memory, but because of the small number of patients in this study the findings should be considered tentative.
Basilar Artery Migraine: Transcranial Doppler EEG and SPECT From the Aura Phase to the End
Authors: Spina I. La , Vignati A. , Porazzi D.
Published: March 2003

Transcranial Doppler, electroencephalography, and single photon emission computed tomography were performed in a case of basilar migraine during the different phases of the attack. In the aura phase, the patient had bilateral blindness and ataxia. Doppler ultrasound studies showed a reduction in the mean flow velocity of the posterior cerebral arteries, electroencephalography showed slow activity confined to the posterior regions, and single photon emission computed tomography, an area of hypoperfusion in the right parietal and occipital regions. During the headache phase, when the neurological examination was normal, transcranial Doppler showed an increase in the mean flow velocity of both posterior cerebral arteries and the electroencephalogram revealed an increase: in the slow activity over the occipital regions. When the pain subsided, the electroencephalogram showed a progressive reduction of the slow abnormalities and transcranial Doppler was reported as normal. After a week, single photon emission computed tomography and cranial magnetic resonance imaging were normal. After a month, a follow‐up electroencephalogram was also normal. All these findings indicated a transient focal reduction of cerebral blood flow during the aura phase.
Parent Responses to Pediatric Headache
Authors: Wall Barbara A. , Holden E. Wayne , Gladstein Jack
Published: March 2003

Evaluated child and parent report versions of a 16‐item parent response to children's recurrent pain episodes scale (PR‐PAIN) on a sample of 153 pediatric headache patients. Factor analyses yielded three factors—Solicitous, Affiliative/Distracting, and Negative responses—for each report form. Correlations among factor scores provided evidence for convergent and discriminant validity. Factor scores from the parent and child report scales were differentially related to levels of episode‐specific disability and overall behavior problems, supporting the criterion‐related validity of both the child and parent measures, The PR‐PAIN scale may assist in performing a thorough functional analysis of pediatric headache and other pain‐related problems.