bluuebunny/crossref_metadata_2025 huggingface dataset:
Biological Activity of Endogenous Atrial Natriuretic Peptide During Cardiopulmonary Bypass
Authors: Hayashida Nobuhiko , Chihara Shingo , Kashikie Hideyuki , Tayama Eiki , Yokose Shogo , Akasu Koji , Aoyagi Shigeaki
Published: March 2003

Abstract: To evaluate the effect of cardiopulmonary bypass (CPB) on atrial natriuretic peptide (ANP) biological activity in patients undergoing cardiac operations, we conducted a prospective study. Ten patients undergoing mitral valve surgery were enrolled. Plasma levels of ANP and cyclic guanosine monophosphate (cGMP), hemodynamic variables, and renal function parameters were assessed perioperatively. The molar ratio of cGMP to ANP (as a marker for ANP biological activity) decreased significantly (p < 0.05) during CPB despite similar plasma ANP levels. The ratio correlated inversely with the duration of CPB (r = −0.85, p = 0.002). The ratio also correlated with fractional sodium excretion (r = 0.65, p = 0.04) and correlated inversely with pulmonary vascular resistance (r = −0.79, p = 0.009) and atrial filling pressure (r = −0.84, p = 0.003) postoperatively. CPB decreased the molar ratio of cGMP to ANP, which may represent ANP biological activity, such as vasodilation and natriuresis. The phenomenon may contribute to water–sodium retention and pulmonary hypertension after cardiac surgery.
The Effect of Biofiltration on Red Blood Cells 2.3‐diphosphoglycerate and pH
Authors: Umimoto Koichi , Hirai Yasuhiro , Hayashi Toshio , Tanaka Hiroshi
Published: March 2003

Abstract: To investigate the effect of biofiltration (BF) on the ability of blood to supply oxygen to the peripheral tissues, a 2 week crossover study was conducted with bicarbonate hemodialysis (BcHD) and BF using 5 male patients with diabetic renal failure as subjects. BcHD and BF were performed for 4 h and 3.5 h per session, respectively. Blood gases, the pH of red blood cells (RBC‐pH), and 2.3‐diphosphoglycerate in RBC (RBC‐2.3DPG) were measured during each treatment. After a 2 week BF treatment, the plasma HCO3− at the beginning of BF was significantly higher than that of BcHD (p < 0.01), and the blood pH improved with an elevated plasma bicarbonate level (p < 0.05). The RBC‐pH at the beginning of BF was higher than that of BcHD (p < 0.05) although the RBC‐pH at the end of both therapies increased to similar levels. The RBC‐2.3DPG during BcHD remained unchanged, but during BF significantly increased (p < 0.05). Metabolic acidosis was significantly improved by BF with its effect reaching to the RBC intracellular level. The improved metabolic acidosis might occur as a result of the increase in RBC‐2.3DPG during BF. This increase in RBC‐2.3DPG has the effect of reducing the affinity of oxygen for hemoglobin and allows more oxygen to be delivered to the peripheral tissues although the increase in RBC‐pH by dialysis restricts the dissociation of oxygen from hemoglobin.
The Use of Electrolyzed Solutions for the Cleaning and Disinfecting of Dialyzers
Authors: Tanaka Noriaki , Tanaka Noriko , Fujisawa Tatsuya , Daimon Toshiya , Fujiwara Kouichi , Yamamoto Masanori , Abe Tomiya
Published: March 2003

Abstract: Recently, the use of electrolyzed solutions has attracted considerable interest in Japan. This study investigates the efficiency of electrolyzed solutions as disinfecting agents (DA) in the reuse of dialyzers and compares their efficiency to that of other disinfectants currently in use. The following 3 methods were employed. First, the rinsing time and rebound release of reused dialyzers were measured and compared after electrolyzed solutions, electrolyzed strong acid aqueous solution (ESAAS) and electrolyzed strong basic aqueous solution (ESBAS), made from reverse osmosis (RO) water (ESAAS, ESBAS; Generating apparatuses: Super Oxseed α 1000, Amano Corporation, Yokohama, Japan), 2% Dialox‐cj (Teijin Gambro Medical, Tokyo, Japan), and 3.8% formalin were used as DAs. This involved performing dialysis with 2 types of dialyzers: a cellulose acetate membrane (CAM) dialyzer and a polysulfone membrane (PSM) dialyzer. The dialyzers were cleaned and disinfected using the different DA and left for 48 h. Next, after performing dialysis the dialyzer membranes were cleaned with a saline solution (0.9% NaCl) and RO water and then cleaned with the various DA. These membranes were observed using a scanning electron microscope (SEM) to check for the presence of physical and biological contaminants. Finally, in vitro tests were performed to determine the level of dialyzer clearance when PSM dialyzers were reused after having been cleaned and disinfected with the electrolyzed solutions. The rinsing time results for both the CAM and PSM dialyzers showed the electrolyzed solutions (ESBAS and ESAAS) as being undetectable within 10 min. With regard to the rebound release, for both the CAM and PSM dialyzers, the electrolyzed solutions were undetectable at all checking times between 30 and 240 min. Observation by SEM showed that cleaning with both ESAAS and ESBAS left the fewest contaminants, and cleaning with 2% Dialox‐cj left the highest level of contaminants in the CAM dialyzers. With regard to experiments concerning use in vitro, no major changes in the dialyzer clearance were noticed after 6 uses. In every experiment, the previous investigations showed the electrolyzed solutions to be superior to 3.8% formalin and 2% Dialox‐cj DA for the reuse of dialyzers.
Development of Rotary Blood Pump Technology: Past, Present, and Future
Authors: Nosé Yukihiko , Yoshikawa M. , Murabayashi S. , Takano T.
Published: March 2003

Abstract:Even though clinical acceptance of a nonpulsatile blood flow was demonstrated almost 45 years ago, the development of a nonpulsatile blood pump was completely ignored until 20 years ago. In 1979, the first author's group demonstrated that completely pulseless animals did not exhibit any abnormal physiology if 20% higher blood flows were provided to them. However, during the next 10 years (1979–1988), minimum efforts were provided for the development of a nonpulsatile, permanently implantable cardiac prosthesis. In 1989, the first author and his team at Baylor College of Medicine initiated a developmental strategy of various types of nonpulsatile rotary blood pumps, including a 2‐day rotary blood pump for cardiopulmonary bypass application, a 2 week pump for ECMO and short‐term circulatory assistance, a 2 year pump as a bridge to transplantation, and a permanently implantable cardiac prosthesis. Following the design and developmental strategy established in 1989, successful development of a 2‐day pump (the Nikkiso‐Fairway cardiopulmonary bypass pump) in 4 years (1989–1993), a 2 week pump (Kyocera gyro G1E3 pump) in 6 years (1992–1998), and a bridge to transplant pump (DeBakey LVAD—an axial flow blood pump) in 10 years (1988–1998) was made. Currently, a permanently implantable centrifugal blood pump development program is successfully completing its initial Phase 1 program of 5 years (1995–2000). Implantation exceeded 9 months without any negative findings. An additional 5 year Phase II program (2000–2005) is expected to complete such a device that will be clinically available.
Functional and Biological Test of a 20 Channel Implantable Stimulator in Sheep in View of Functional Electrical Stimulation Walking for Spinal Cord Injured Persons
Authors: Bijak Manfred , Mayr Winfried , Girsch Werner , Lanmüller Hermann , Unger Ewald , Stöhr Hans , Thoma Herwig , Plenk Hanns
Published: March 2003

Abstract: A newly developed implantable stimulator with 20 output channels, mainly intended for the stimulation of lower extremities in paraplegics, was implanted in 6 sheep over a time period of 26 weeks. Five epineural electrodes each were used to contact various nerves at different locations to elicit hip and knee extension and flexion and to make carrousel and selective stimulation possible. Different electrode application strategies in view of paraplegic standing and walking were investigated. Additional implanted electrodes allowed M‐wave monitoring for selectivity investigations in 3 sheep. Stimulator, electrode leads, and electrodes proved to be reliable. Selective stimulation with electrodes placed on the trunk of the sciatic nerve could be demonstrated but with bad reproducibility. Histological investigation of the tissues surrounding electrodes and leads showed the expected stable foreign body response. Strong hip and knee extension could be gained in all cases while only weak flexion forces could be elicited in most cases. Muscle biopsies showed that daily stimulation for 8 h at threshold level caused an increase in muscle Type I fibers and a decrease in Type IIc fibers. Implants and electrodes fulfill the most important functional and biological criteria for their clinical application for paraplegic walking. The intention to provide selective flexion functions via epineural stimulation could not be demonstrated sufficiently in this animal model.
In Vitro and In Vivo Evaluation of Albumin Synthesis Rate of Porcine Hepatocytes in a Flat‐Plate Bioreactor
Authors: Shito Masaya , Kim Nam Heui , Baskaran Harihara , Tilles Arno W. , Tompkins Ronald G. , Yarmush Martin L. , Toner Mehmet
Published: March 2003

Abstract: Several configurations of extracorporeal bioartificial liver devices have been developed for the potential treatment of fulminant hepatic failure or as a bridge to liver transplantation. Recently, we developed a microchannel flat‐plate bioreactor with an internal membrane oxygenator in which porcine hepatocytes are cultured as a monolayer on the bottom glass surface. In the present study, we investigated synthetic function of porcine hepatocytes in the bioreactor in both in vitro and in vivo flow circuit models. In vitro, albumin synthesis was stable in the bioreactor for up to 4 days of perfusion. In vivo, with the extracorporeal connection of the bioreactor to rat vasculature, porcine albumin was detectable for 24 h in the rat plasma. We also developed a simple mathematical model to predict the in vivo porcine albumin concentration in rat plasma. These results indicate that this configuration of a microchannel flat‐plate bioreactor has potential as a liver support device and warrants further investigation.
Estimation of Left Ventricular Recovery Level Based on the Motor Current Waveform Analysis on Circulatory Support with Centrifugal Blood Pump
Authors: Takahashi K. , Uemura M. , Watanabe N. , Ohuchi K. , Nakamura M. , Fukui Y. , Sakamoto T. , Takatani S.
Published: March 2003

Abstract: In a mock circulatory loop simulating the left heart bypass using a centrifugal blood pump, analysis of the motor current waveform of the centrifugal pump was performed to derive a useful parameter to evaluate the status of ventricular function. The relationship between the peak, amplitude, and the peak of the fundamental frequency of the power spectral density of the periodic motor current waveform (MCpsdP) that reflected the pulsatile ventricular pressure, and the peak of the left ventricular pressure (LVP) was examined. Although both peak and amplitude of the motor current waveform showed an excellent correlation with the peak LVP, they failed to predict the opening of the aortic valve. The MCpsdP that corresponds to the frequency of the heart rate showed an excellent correlation with the peak LVP throughout the LVP levels, but the slope between them changed with the opening of the aortic valve. Thus, it is possible to follow the change in the LVP and detect even the opening of the aortic valve, and, hence, the recovery of the left ventricle. However, the slope of the linear regression equation varied, depending on the pump speed. This result implies that the MCpsdP can be possibly used to follow the change of ventricular function during circulatory assistance with a centrifugal blood pump as well as to control the pump speed in response to varying ventricular function.
Different Low Constant Flows Can Equally Determine the Lower Inflection Point in Acute Respiratory Distress Syndrome Patients
Authors: Gama Ana Maria Casati Nogueira , Meyer Eduardo Correa , Gaudêncio Ana Maria Araújo Silva , Grunauer Michelle Andrade , Amato Marcelo Britto Passos , De Carvalho Carlos Roberto Ribeiro , Barbas Carmen Sílvia Valente
Published: March 2003

Abstract: Among the possible techniques to obtain the pressure–volume (P × V) curve at the bedside the low constant flow (CF) is the easiest and quickest one. However, the best value for CF to perform a good semistatic P × V curve is still to be determined. The purpose of this study was to evaluate the influence of 4 different CFs (1, 2, 5, and 10 L/min) on determination of lower inflection point of the P × V curve (L‐Pflex) and upper inflection point of the P × V curve (U‐Pflex) on the maximum slope and on the inspiratory work of breathing (up to volume of 1.35 L; inspiratory work L/cm H2O), comparing the volume estimated from the CF with the measured volume obtained by the respiratory inductive plethysmograph. The design was a prospective study, and the setting was an adult medical intensive care unit of a university hospital. There were 7 acute respiratory distress syndrome (ARDS) patients, less than 5 days of installation, after the standardization of lung volume history received sequentially from 4 different low inspiratory CFs in 2 trials. The P × V curve lasted from 73 ± 1.6 s (1 L/min) to 8.8 ± 0.69 s ( 10 L/min). The L‐Pflex differed in the 2 performed trials (p = 0.04). There was no difference of L‐Pflex among the 4 CFs comparing the 3 methods (p = 0.072) used for its calculation as well as comparing the estimated and the measured volume (p = 0.456). The maximum slope decreased significantly while increasing the flow from 1 to 10 L/min just in the estimated volume (p = 0.03). The inspiratory work did not increase with the increment of the flow either in the estimated volume (p = 0.217) or in the measured volume (p = 0.149). The U‐Pflex differed among the trials (p = 0.003) and the methods used for its calculation (p < 0.01). Constant flows from 1 to 10 L/min can equally determine L‐Pflex in ARDS patients and is an easy and quick way to obtain the L‐Pflex in order to optimize positive end expiratory pressure (PEEP) in ARDS patients.
An Investigation of Blood Damage Induced by Static Pressure During Shear‐Rate Conditions
Authors: Yasuda Toshitaka , Funakubo Akio , Fukui Yasuhiro
Published: March 2003

Abstract: Many investigators have studied the effect of a mechanical force (shear rate, pressure, or temperature) on hemolysis. However, there exists no investigation of a relationship between the interactions of mechanical forces and hemolysis. The purpose of this study is to investigate the interactions of mechanical forces on hemolysis. We performed in vitro tests by using bovine blood, applying shear rate (0, 500, 1,000, and 1,500 s−1), positive pressure (0, 200, 400, and 600 mm Hg), and temperature (21, 28, and 35°C) simultaneously. In all temperatures at the shear rate of 1,500 s−1, there are statistically significant differences in the hemolysis rate between 0 and 600 mm Hg (p < 0.05). However, to investigate the effect of temperature on hemolysis, shear stress was calculated at each blood temperature. There were no statistically significant differences among them. The results suggested that erythrocyte trauma caused by pressure related to the level of shear rate. It was found that the causes of hemolysis included the shear rate as well as shear rate and pressure.
Effects of Ethylene Oxide and Steam Sterilization on Dialysis‐Induced Cytokine Release by Cuprophan Membrane
Authors: Aucella Filippo , Vigilante Mimmo , Gatta Giuseppe , Grandone Elvira , Colaizzo Donatella , Margaglione Maurizio , Modoni Sergio , Stallone Carmine
Published: March 2003

Abstract: The effects of sterilization modalities on dialysis‐induced cytokine release are still unknown. To investigate these effects, 8 patients on chronic hemodialysis were enrolled for evaluating at different intervals interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α) production (pg/ml/106). They were using a 1.3 m2 ethylene oxide (E3) or steam (E3S) sterilized Cuprophan membrane. The patients underwent a basal test with E3 (A1) and 2 following tests after 1 (B1) and 2 (B2) months of E3S treatment, respectively. Finally, the last test was performed 1 month after the switch to E3 (A2). Il‐1β predialysis release by mononuclear cells was 162 ± 114 pg/ml/106 in A1, 185 ± 129 pg/ml/106 in B1, and 226 ± 138 pg/ml/106 in B2, then decreased to 123 ± 134 in A2 (p < 0.07). Il‐1β postdialysis levels were 234 ± 238 pg/ml/106 in A1, 429 ± 285 pg/ml/106 (B1), and 438 ± 473 pg/ml/106 (B2) with the steam membrane, decreasing to 204 ± 134 pg/ml/106 in A2 (p < 0.01). TNF‐α predialysis basal release (A1) was 826 ± 817 pg/ml/106, 720 ± 496 in B1, and 1079 ± 515 pg/ml/106 in B2, and finally 680 ± 588 pg/ml/106in A2 (p < 0.03). In postdialysis TNF‐α levels were 963 ± 542 pg/ml/106 in A1, 1,226 ± 541 pg/ml/106, and 1,183 ± 776 in B1 and B2 respectively, and 388 ± 297 pg/ml/106 in A2 (p < 0.003). Steam sterilization seems to induce a higher cytokine release by mononuclear cells when a Cuprophan membrane is used. This finding may be related to a less physiologic action of the steam in the case of Cuprophan membranes. Further studies are needed to clarify this hypothesis.
Modulation of Hepatocyte Function in an Immortalized Human Hepatocyte Cell Line Following Exposure to Liver‐Failure Plasma
Authors: McCloskey Paschal , Tootle Rosemary , Selden Clare , Larsen Fin , Roberts Eve , Hodgson Humphrey J.F.
Published: March 2003

Abstract: For hepatocytes to function effectively in a bioartificial liver device, maintained function in the milieu of plasma from patients with liver failure will be required. We have investigated the effect of plasma obtained at plasmapheresis from patients with acute liver failure on the performance of the human hepatocyte cell line HHY41 in liver‐failure plasma, normal plasma, and culture medium. Cytotoxicity of plasma, DNA synthesis by thymidine incorporation, oxidative status, and cytochrome P450 functions were assayed after a 16 h culture with normal plasma, liver‐failure plasma, or culture medium. Some, but not all, samples of liver‐failure plasma were deleterious to the performance of the cell line, inducing cytotoxicity and oxidative stress, with diminished DNA synthesis, protein synthesis, and cytochrome P4501A activity. Strategies to minimize the toxic effects of liver‐failure plasma may improve the performance of liver cells in extracorporeal liver‐support devices.
The Effect of Apo‐Transferrin on Bacterial Adhesion to Biomaterials
Authors: Ardehali Reza , Shi Lei , Janatova Jarmila , Mohammad S. Fazal , Burns Gregory L.
Published: March 2003

Abstract: Apo‐transferrin (apo‐Tf), the iron deficient form of Tf, has been identified previously as a potent inhibitor of Staphylococcus epidermidis adhesion to polyurethane surfaces. In this study, the ability of apo‐Tf to suppress the adhesion of two other strains of bacteria, namely a Gram‐positive Staphylococcus aureus and a Gram‐negative Pseudomonas aeruginosa to several biomaterials, including polystyrene, polymethylmethacrylate, and silicone, is documented. The presence of apo‐Tf in the medium at 20 μg/ml lowered bacterial adhesion to all tested biomaterials more than fourfold. Moreover, apo‐Tf exerted its inhibitory activity even when protein coated surfaces were used as substrates for bacterial adhesion. To emphasize the importance of apo‐Tf in the prevention of bacterial adhesion, human serum was depleted of Tf, employing affinity chromatography, and was shown to lose its inhibitory activity toward bacterial adhesion. Upon addition of apo‐Tf to Tf‐depleted serum, the activity was reestablished, resulting in a marked reduction in the number of bacteria adhered to the surfaces. Following the enzymatic deglycosylation, apo‐Tf retained its ability to prevent bacterial adhesion. These results indicate that the carbohydrate moiety does not seem to play a role in this activity. The presented data provide the evidence that the inhibitory activity of apo‐Tf is not bacterial strain specific and that the presence of apo‐Tf in the medium results in a significant reduction of bacterial adhesion to a variety of neat and/or protein coated surfaces.
A Personal User's View of Functional Electrical Stimulation Cycling
Authors: Fitzwater Roger
Published: March 2003

Abstract: Two years of functional electrical stimulation cycling (FESC) as a researcher and subject have given me an insight into the direction that future FESC should take as well as providing me with significant health benefits and an enjoyable and functional ability to cycle. If FESC is to benefit spinal cord injured persons (SCIPs), researchers must turn their attention to making the activity convenient and enjoyable. What follows is a personal view and will be less scientifically rigorous than other presentations but hopefully still of value. It calls upon my experience as a general medical practitioner with a special interest in the value of exercise, a human powered vehicle enthusiast, an amateur FES researcher, but most importantly, an SCIP and FES cyclist.
Twenty‐Eight Years of Clinical Experience with Implantable Neuroprostheses for Various Applications
Authors: Davis Ross
Published: March 2003

Abstract: Since 1973, the author has been implanting neural stimulators and later drug pumps to restore or improve motor function and modulate pain, spasticity, and seizures in patients with spinal cord and brain injury, cerebral palsy, stroke, and multiple sclerosis. During these 28 years, many physicians, biomedical engineers, and manufactures have realized worthwhile successes. Many lessons have been learned to improve operative techniques to ensure safety, low infection, and improved results for implant patients. The relationships between manufacturers and physicians have varied. Problems arise with patents, royalties, confidentiality, publishing, and liability insurance. There has been a need to patent ideas and intellectual properties; however, some of the patented concepts have been published previously but missed by the patent author and patent office. This has led to vigorous legal battles, consuming money with time delays, or resulting in surrendering worthwhile projects. There is a need for a responsible, independent appeals board to review these disputed patent claims. Then their findings should be admissible at the Patent Office and if necessary in court.
Intensive Imaging Assessment for Successful Minimally Invasive Cardiac Surgery
Authors: Kitamura Masaya , Namura Osamu , Hanzawa Kazuhiko , Nakayama Takashi , Meguro Atsushi , Hayashi Jun‐ichi
Published: March 2003

Abstract: To clarify special imaging assessment that is useful for minimally invasive cardiac surgery (MICS), we examined 141 cases of MICS operations with ministernotomy or minithoracotomy. In the 141 patients, 62 valve, 42 coronary, 37 congenital heart, and 2 other procedures were successfully completed without conversion to full sternotomy. Preoperative chest x‐ray, computed tomography, and/or magnetic resonance imaging were necessary for determining the level of ministernotomy, especially in aortic valve operations. Transthoracic echocardiography was useful for selecting procedures of mitral valve or intracardiac repair through the MICS approach. Intraoperative transesophageal echocardiography was essential for continuous monitoring of cardiac function, intracardiac flow, air bubbles, and so forth. The above results suggest that intensive imaging assessment might be very important for successful MICS operations with ministernotomy or minithoracotomy and that extensive indications for this technique exist for various cardiovascular diseases.
Minimally Invasive Cardiac Surgery by the Port‐Access Method
Authors: Yozu Ryohei , Shin Hankei , Maehara Tadaaki
Published: March 2003

Abstract: Recently, minimally invasive surgery has come to be an important theory in cardiac surgery, the goal of which is shortening of hospital stay, earlier recovery of employment, and cosmetics. In this paper, we will describe our experience with port‐access cardiac surgery conducted under the support of our new technology. This study assesses the quality of cardiac surgery performed by the port‐access method. The author developed a direct endoaortic clamp balloon (Yozu balloon). This balloon is a triple‐lumen balloon catheter of 3.6 mm in outer diameter and 40 cm in full length. The balloon is inserted directly into the ascending aorta. Injection of cardioplegic solution and aortic vent can be conducted. Also, we introduce a modified Cosgrove flex clamp to apply in small‐incision surgery, aiming at a less invasive procedure. The modified point is that the original, united Cosgrove flex clamp can be divided into the handle part equipped with a ratchet, and the bellows part equipped with a clamp jaw. By this modification, it became possible to apply the Cosgrove flex clamp transthoracically; that is, it became possible to conduct aortic clamping safely and securely through this small port of 8 mm in diameter. Port‐access cardiac surgery is one of the developing and promising methods of cardiac operation. In view of future technological progress, we can expect the gradual but wide popularization of this method.
Mock Loop Testing of On‐X Prosthetic Mitral Valve with Doppler Echocardiography
Authors: Verdonck Pascal R. , Dumont Kris , Segers Patrick , Vandenberghe Stijn , Van Nooten Guido
Published: March 2003

Abstract: Previous in vitro testing (mainly in aortic position) and clinical experience (often based on Doppler echocardiographic observations) demonstrated an excellent hemodynamic behavior of the On‐X valve. However, integrative studies including simultaneous hemodynamic pressure and flow measurements and Doppler echocardiography are lacking. Using our computer‐controlled mock loop system, two samples of the Mitral 27/29 and one sample of the Conform‐X Mitral 25/33 are tested in mitral position. Data include transvalvular pressure gradient and flow as well as transthoracic Doppler echocardiography. The valves are tested under three pressure conditions (ventricular systolic pressure of 100, 130, and 160 mm Hg) at three different heart rates (60, 100, and 140 beats/min). In addition, ventricular pressure conditions simulating fibrillation are imposed. Both valve types show similar hydrodynamic characteristics and have an effective orifice area of 2.1 cm2 and a performance index of 0.56 for a cardiac output of 3.5 L/min. Regurgitant volumes remain below 6 ml.
Cooling Device for Bradycardia Based on Peltier Element for Accurate Anastomosis of Off‐Pump Coronary Artery Bypass Grafting
Authors: Kuniyoshi Yukio , Koja Kageharu , Miyagi Kazufumi , Shimoji Mituyoshi , Uezu Tooru , Arakaki Katuya , Yamashiro Satoshi , Mabuni Katuhito , Senaha Shigenobu
Published: March 2003

Abstract: Upon introducing off‐pump coronary artery bypass grafting (CABG), the indications for CABG were expanded to include patients who previously had no operative indications. For accurate anastomosis, various devices and methods have been developed. Bradycardia is easily induced by drug administration. However, this method of achieving bradycardia also has adverse effects on cardiac function. We have developed a new device to decrease the heart rate by regional cooling of the sino‐atrial node. The new device is incorporated with Peltier's element, which uses an electric charge to create a temperature gradient on both of its surfaces. In terms of the cooling ability of this device, its cooling surface is chilled from 25°C to 0°C within 30 s. During in vivo animal experiments, this device has been shown to decrease the myocardial temperature around the sino‐atrial node to 15°C and suppress sino‐atrial node activity, resulting in bradycardia to 60 beats/min level. In summary, the simple and easily applicable device for local cooling in combination with the application of diltiazem for effective heart rate reduction may be very helpful for the surgeon and may avoid disadvantages for critically ill patients.
Mesenteric Complications After Hypothermic Cardiopulmonary Bypass with Cardiac Arrest: Underlying Mechanisms
Authors: Andrási Terézia Bogdana , Buhmann Volker , Soós Pál , Juhász‐Nagy Alexander , Szabó Gábor
Published: March 2003

Abstract: The aim of this study was to determine the pathophysiological mechanisms of postcardiopulmonary bypass (CPB) intestinal dysfunction using an in vivo canine model of extracorporeal circulation. Six dogs underwent a 90 min hypothermic CPB with continuous monitoring of mean arterial blood pressure (MAP) and mesenteric blood flow (MBF). Reactive hyperemia and vasodilator responses of the superior mesenteric artery to acetylcholine and sodium nitroprusside were determined before and after CPB. Mesenteric lactate production, glucose consumption, creatine kinase (CK) release and venous free radicals were determined. CPB induced a significant fall (p < 0.05) in MAP and MBF. After CPB, reactive hyperemia (−26 ± 15% versus −53 ± 2%, p < 0.05) and the response to acetylcholine (−42 ± 9 versus −55 ± 6%, p < 0.05) were significantly decreased. Reperfusion increased lactate production (0.8 ± 0.09 mmol/L versus 0.4 ± 0.18, p < 0.05) and the CK release (446 ± 98 U/L versus 5 ± 19 U/L, p < 0.01). Endothelial dysfunction, conversion from aerobic to anaerobic metabolism, and intestinal cell necrosis seem to be responsible for intestinal complications associated with CPB.
Korean Artificial Heart (AnyHeart): An Experimental Study and the First Human Application
Authors: Sun Kyung , Son Ho Sung , Jung Jae Seung , Cheong Bong Kyu , Shin Jae Seung , Kim Kwang Taik , Lee Hye Won , Ahn Sang Su , Park Sung Young , Oh Hye Jung , Lee Hwan Sung , Shim Eun Bo , Rho Yang Rae , Lee Hyuk Soo , Min Byoung Goo , Kim Hyoung Mook
Published: March 2003

Abstract: A Korean artificial heart (AnyHeart) has been implanted in 29 various animals (52–470 kg) to evaluate hemodynamic performance and electromechanical stability. Most were implantable biventricular assist devices in use. A right thoracotomy approach has been a standard technique of implantation. A preclinical fitting test was also performed to observe anatomical feasibility and to compare surgical techniques in 10 human cadavers. The first case of human application was made as a lifesaving procedure on June 12, 2001.
Extreme Cases: A Strategy for Ecological Risk Assessment in Ecosystem Health
Authors: Hood Robert L.
Published: March 2003

ABSTRACT

I contend that focusing on the “absence of health,” or what I will call “extreme cases,” provides a basis for agreement about ecosystem health in ecosystem management. An extreme case is defined where there exists (1) scientific agreement about models, (2) scientific agreement about scale, (3) policy agreement that the risks will be great and unnecessarily so. Scientific agreement requires that a link be established between biodiversity and ecosystem processes, goods, and services. I discuss recent work concerning ecosystem engineers that demonstrates such a link. Agreement about scale requires consensus about the scale of management decisions, both spatial and temporal, and reconciliation of management goals and objectives of the various stakeholders in an ecosystem. Finally, policy agreement requires that ecological risks be great and unnecessarily so. Where these extreme cases do not apply, I suggest that it will be useful to appeal to stakeholder negotiations to seek agreement concerning ecosystem health.
The Importance of Dispersal Mechanisms in the Epidemiology of Phytophthora Blights and Downy Mildews on Crop Plants
Authors: Campbell C. Lee
Published: March 2003

ABSTRACT Epidemics of plant diseases share a basic structure with those of human and animal diseases; however, unlike most epidemics of people and animals, fungi or fungi‐like organisms are of major importance as pathogens. Because of the relatively low value of an individual in most plant populations, botanical epidemiologists perform observational as well as designed studies repeatedly on epidemics in large populations. Plant disease epidemics develop from overlapping cycles of propagule dissemination, host encounter and infection, pathogenesis (including symptom development), and pathogen reproduction. Initial infective units, or propagules, originate from survival structures formed between cropping seasons or during periods when weathers conditions are not suitable for disease initiation. Propagules may also arrive by long‐distance transport from other geographic areas where conditions are suitable for the occurrence of continuous epidemic cycles. The importance of dispersal mechanisms in epidemic development are illustrated with three solanaceous pathosystems: Phytophthora blight of pepper (caused by Phytophthora capsici), blue mold of tobacco (caused by Peronospora tabacina), and late blight of potato (caused by Phytophthora infestans).
The Links Between Industrial, Community, and Ecological Sustainability: A Forestry Case Study
Authors: Ostry Aleck
Published: March 2003

ABSTRACT According to Harold Innis, Canada's economic history has been based on the discovery of natural resources, consequent community formation to facilitate their extraction, resource depletion, and finally, community disappearance. This model links industrial change and development in the resource sector with both community and ecological outcomes but neglects detailed exploration of the industry/ecosystem linkage. The purpose of this paper is to adapt the ecological footprint concept in order to make the ecological impact of economic and technological change in a Canadian resource industry (sawmilling) explicit. This investigation utilizes a large cohort of sawmill workers gathered in 14 British Columbia (B.C.) mills, a study that measured the ecological footprint in several of these mills, and a labor adjustment study conducted by Statistics Canada to explore the links between technological change and downsizing in this resource industry and both community and ecological sustainability. The ecological footprint concept is adapted for use in a resource‐extracting industry. This allows moving the estimation of the ecological footprint from its usual place, an urban consuming population, to the site of natural capital transformation (the sawmill) thereby linking the costs and benefits of this transformation with site or region‐specific ecosystem exploitation. Results demonstrate that the recession of the early 1980s eliminated over 40% of the sawmill workforce and stimulated increased replacement of labor by capital, thus increasing productivity and the ecological footprint of sawmills. The new technical infrastructure now in place in most sawmills is accelerating the pace of forest ecosystem draw‐down while at the same time producing less economic benefit for the local community. Adaptation of the ecological footprint for use at the site of the transformation of natural capital makes these trade‐offs more specific.
Lessons from Preventive Medicine for the Precautionary Principle and Ecosystem Health
Authors: Calver M.C.
Published: March 2003

ABSTRACT Preventive medicine establishes clear links between diseases and their causes, therefore illness can be averted or minimized by preventive measures. If this information is widely dispersed through community education, it empowers individuals to undertake decisions likely to improve their health. Significant cost savings are often possible because preventive measures may be cheaper than curative ones. In the case of ecosystem health, the precautionary principle is analogous to preventive medicine because it argues for anticipatory action to protect the environment from possible serious or irreversible harm. The precautionary principle empowers people by involving them in environmental decisions and has a clear need for community education to encourage awareness and participation. It may also save society money in the long term by avoiding the costs of ecological rehabilitation. However, the precautionary principle is fundamentally different from preventive medicine because it argues that action to protect the environment should be undertaken if a causal relationship is only suspected, not established. Thus, the analogy of preventive medicine and the precautionary principle is valuable in highlighting this critical difference and suggests that the precautionary principle will always be deeply contentious because of its focus on uncertainty.
Monitoring Seagrass Ecosystem Health—The Role of Perception in Defining Health and Indicators
Authors: Wood N. , Lavery P.
Published: March 2003

ABSTRACT Thirty‐four seagrass researchers/managers were asked to identify seagrass sites in Cockburn Sound, Western Australia, which they perceived to be healthy or unhealthy, and indicate the basis for these perceptions. The average respondent based their perception on three variables, ranging from ecosystem features to plant attributes. Four variables were considered very important in developing perceptions: canopy cover, shoot density, epiphyte biomass, and the proportion of calcareous epiphytes. Three sites perceived to be healthy and three perceived to be unhealthy were then compared to determine if features indicated as important in developing perceptions about health differed between the sites. None of the four variables considered important by respondents differed statistically between “healthy” and “unhealthy” sites in winter, but shoot length and above ground biomass were different. In summer, two of the important variables (canopy cover and shoot density) differed, along with shoot height, productivity, and leaf area index. Despite their perceived importance, epiphyte features were not different between perceived healthy and unhealthy sites. The study suggests that shoot density, canopy cover, shoot height, above ground biomass, productivity, and leaf area index of P. angustifolia ecosystems differ statistically between sites perceived to be healthy and unhealthy. However, the usefulness of these variables as indicators of seagrass health varies seasonally. Health was clearly a respondent‐dependent concept. The basis of perceptions about health among a group of expert scientists did not correspond strongly to measurable differences between sites. The unwarranted importance placed on epiphytes may be due to previous studies that have reinforced their importance. These observations highlight the role of personal perspective and scientific preconditioning in forming concepts of health, and raise the question of the role that “experts” should be playing in formulating those concepts.
Occipital Lobe Tumor Presenting as Migraine With Typical Aura
Authors: Verma Ashok , Rosenfeld Victor , Forteza Alajanc ro , Sharma Khema R.
Published: March 2003

We report the case of a 60‐year‐old woman in whom migraine with typical aura heralded the presence of an occipital lobe tumor. Her headache was characterized by recurrent episodes of visual aura confined to the left visual field followed by right hemicranial throbbing headaches accompanied by nausea, photophobia, and phonophobia. Interictal neurologic and ophthalmologic examinations were negative, as was an unenhanced brain CT scan. The headaches increased in frequency over 4 months despite a number of medications known to prevent attacks of migraine.

A low‐grade right occipital lobe tumor was eventually discovered on MR scan. This case illustrates that headache fulfilling the International Headache Society (IHS) criteria for migraine with typical aura can occur in association with an occipital lobe tumor.
Effectiveness of Subcutaneous Dihydroergotamine by Home Injection for Migraine
Authors: Becker W. J. , Riess C. M. , Hoag J.
Published: March 2003

The effectiveness of dihydroergotamine administered by home subcutaneous injection by the patient or family for severe headache attacks was assessed retrospectively in 51 patients. Average follow‐up was 21 weeks. Twenty‐one patients had intermittent migraine attacks, 27 had transformed migraine with chronic daily headache, and 3 had chronic tension‐type headache. Of the 51 patients taught home injection, 35% had an excellent overall response 18% had a good response, 12% had a poor response but continued to use dihydroergotamine, and 35% had discontinued dihydroergotamine use. Side effects were the main reason for stopping dihydroergotamine. These included nausea or vomiting or both, limb pain or numbness or both, chest or throat tightness or both, and soreness at the injection site. Thirty‐three patients (65%) continued to use dihydroergotamine at the end of the follow‐up period. In patients who previously required injections from medical personnel for headache crises and in whom home injection of dihydroergotamine was effective, a dramatic reduction occurred in hospital emergency room and physician office utilization. Dihydroergotamine use by home injection can be an effective treatment for a significant proportion of patients with severe migraine including patients with transformed migraine and medication overuse.
The Placebo Effect in Acute Headache Management: Ketorolac, Meperidine, and Saline in the Emergency Department
Authors: Harden R. Norman , Gracely Richard H. , Carter Timothy , Warner George
Published: March 2003

In a prospective, double‐blind, randomized study, ketorolac 60 mg, meperidine 50 mg plus promethazine 25 mg, and normal saline given by intramuscular injection were compared as treatment for acute headache crises. Thirty patients (6 men and 24 women) presenting to an urban emergency department with any type of benign headache were randomized into three groups and filled out the McGill Short‐Form Paint Questionnaire with a Pain Rating Index and a Visual Analogue Pain scale. They received one of the study medications and repeated the testing after I hour. The objective was to test the efficacy of ketorolac in this population.

Separate analyses of the McGill Short‐Form (Total, Sensory, Affective, and Pain Rating Index scales) and the Visual Analogue Pain scale responses showed that the three treatments produced a significant reduction in pain (P<.0001), but that pain reduction did not differ among the treatments. This profound reduction observed after administration of a placebo prevented accurate evaluation of the effects of ketorolac. The placebo response must be considered in the design of future trials using intramuscular medications in the acute intervention of headache crises. In addition, the use of a standard analgesic is necessary to demonstrate both assay sensitivity and magnitude of response to placebo.
Treatment of Migraine With BMS180048: Response at 2 Hours
Authors: Couch James R. , Saper Joel , Meloche Jacques P.
Published: March 2003

BMS180048 is a 5HT1D agonist that was well‐tolerated in early phase II trials. This study utilized a double‐blind, parallel‐group dose ranging format, comparing BMS180048 in doses of 25, 50, or 75 mg to placebo in effectiveness of treatment of a single migraine headache.

To assess tolerability of BMS180048, patients received a test dose of the medication they would receive for a headache in the clinic under observation. If no significant side effects occurred, patients were allowed to treat a headache. Headaches were moderate or severe in intensity before treatment, and response at 2 hours was tabulated. Reduction to mild or no headache was the criteria for successful response. Response rates at 2 hours were as follows:

• placebo ‐ 19 of 53 subjects (35.8%)

• 25 mg ‐ 21 of 53 subjects (40.3%)

• 50 mg ‐ 34 of 53 subjects (64.2%)

• 75 mg ‐ 35 of 55 subjects (63.6%)

The improvement for subjects treated with 50 or 75 mg of BMS180048 when compared to placebo was highly significant (P<.01). Nausea, photophobia, and phonophobia improved 35% to 50% for BMS180048‐treated subjects and 20% to 24% in the placebo group. The improvement in these symptoms in comparison to placebo was statistically significant only for nausea in those treated with 75 mg of BMS180048 (P=.02). Side effects were mild for the most part, and no serious adverse events occurred. The study suggests BMS180048 is effective in acute symptomatic therapy of migraine.
Impact of Sumatriptan on Clinic Utilization and Costs of Care in Migraineurs
Authors: Litaker David G. , Solomon Glen D. , Genzen Jonathan R.
Published: March 2003

Background.—Although migraine headaches affect a large segment of the population, no objective measure of therapeutic success is currently available. Comparing visit frequency and associated costs of care before and after introduction of a new therapy represents an important surrogatemeasure of success.

Methods.—One hundred four patients regularly attending a headache clinic for migraines at a tertiary care hospital were instructed in the use of a new abortive migraine therapy. Medical appointment and financial systems were searched retrospectively for visit frequency and associated patient care and institutional costs. The number of visits and mean costs 18 months before and after initiation of therapy were compared using the signed rank test and paired t‐test, respectively.

Results.—The median number of visits made by study subjects to the headache clinic fell significantly following sumatriptan test dosing (P<0.001). Prior to the new treatment, mean total patient care and institutional costs were $228.59 and $112.81 per person, respectively, and fell to $135.93 and $78.16 (P<0.001) after therapy began.

Conclusions.—These data suggest that many patients with migraine benefit from sumatriptan, seek medical attention in a headache clinic less often, and incur fewer costs following initiation of treatment with this drug.
Frequency of Magnetic Resonance Imaging Abnormalities in Patients With Migraine
Authors: Cooney Brian S. , Grossman Robert I. , Farber Roger E. , Goin James E. , Galetta Steven L.
Published: March 2003

Background.‐The frequency of magnetic resonance imaging (MRI) abnormalities in patients with migraine has been reported at 12% to 46%. We examined a series of patients to determine the frequency of MRI abnormalities, and any relationship of frequency with patient age, sex, migraine type, duration of symptoms, and other medical conditions.

Methods.‐Magnetic resonance imaging findings were reviewed retrospectively with respect to presence of focal white matter hyperintensities in 185 consecutive patients. Patients had been diagnosed with migraine by a neurologist. All images had been interpreted by a neuroradiologist. Clinical information was obtained by chart review.

Results.‐Sixteen percent had focal white matter abnormalities. Among patients less than 50 years old, and without other medical problems such as hypertension, atherosclerotic heart disease, diabetes mellitus, autoimmune disorder or demyelinating disease, only 6% had white matter abnormalities. Increased frequency of white matter abnormalities was associated with age and medical risk factors, but not with sex, migraine subtype, or duration of migraine symptoms.

Conclusion.‐The observed frequency of MRI abnormalities in our series is lower than has been previously reported. In many cases, these abnormalities may be unrelated to migraine. When such changes are discovered in a patient with migraine, other etiologies should be considered.
Headache and Self‐assessed Depression Scores in Singapore University Undergraduates
Authors: Ho King‐Hee , Ong Benjamin K.C. , Lee Soo‐Chin
Published: March 2003

A self‐administered questionnaire covering the diagnostic criteria of the International Headache Society was completed by 1208 undergraduates of the National University of Singapore to determine the prevalence and characteristics of headaches in this population. The relationship between headaches and depressive illness was investigated with the Zung Self‐assessed Depression Scale. The mean age of respondents was 20.9 ± 1.6 years; 50.3% were men and 46.4%, women. Ten point nine percent had migraine without aura, 29.8% had tension‐type headaches, 1.1% had headaches consistent with migraines with aura, and in 56.3% the headaches could not be classified. The lifetime prevalence of headache in this population was 98.1%. Significantly higher mean Zung scores were found in subjects who had more intense and frequent headaches than in those without headaches and less severe symptoms, al though the clinical relevance of this finding is uncertain Zung scores did not differ significantly with diagnostic group, sex, or race.