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Results 601 - 650 of 1622
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Liu X K - - 1999
Recent clinical observations indicate that female gender is associated with a higher risk of developing torsades de pointes (TdP) cardiac arrhythmia. In this study, we used the Langendorff technique in isolated perfused rabbit hearts and the whole-cell patch-clamp technique in ventricular myocytes to examine the gender difference in TdP incidence ...
Patel S - - 1999
The effect of varying local skin temperature on surface pressure-induced changes in skin perfusion and deformation was determined in hairless fuzzy rats (13.5+/-3 mo, 474+/-25 g). Skin surface pressure was applied by a computer-controlled plunger with corresponding skin deformation measured by a linear variable differential transformer while a laser Doppler ...
Horgan A F - - 1999
PURPOSE: Lower limb compartment syndrome has been reported to occur after colorectal, urological, and gynecological procedures during which the patient's lower limbs are elevated for prolonged periods of time. METHOD: We investigated lower limb perfusion in a group of patients undergoing prolonged pelvic surgery both during and immediately after surgery, ...
Lindström K E - - 1999
Recently, we were able to modify the glomerular charge barrier using perfusates with low and normal ionic strengths keeping the osmolality unchanged. The concentration of fixed charges was reversibly reduced from 35 to 12 mEq L-1 as the solution with low content of NaCl was introduced with no apparent effect ...
Yamamoto H - - 1999
We developed an ex vivo model of arterially perfused rat duodenum to examine the motor activity of intestine. In this preparation, spontaneously occurring pressure waves with regular rhythm were observed. The oxygen consumption and motor activity of the intestine were compared at different arterial perfusion rates to determine the degree ...
Pasini E - - 1999
We have characterized the aerobic blood-perfused isolated heart model evaluating the hemodynamics and metabolism of both the blood donor animal and the isolated organ. Anaesthesia of the blood donor with sodium pentobarbital (30 mg/kg) increases arterial concentration of non esterified fatty acids (NEFA) from 80 +/- 6 to 452 +/- ...
Melsom M N - - 1999
Despite a remarkable gravity independent heterogeneity in both local pulmonary ventilation and perfusion, the two are closely correlated at rest and during exercise in the normal lung. These observations strongly indicate that there is a mechanism for coupling of the two so that local V/Q-ratio is kept fairly uniform throughout ...
Lakey J R - - 1999
Effective intraductal delivery of the enzyme collagenase into the pancreas is crucial to the subsequent ability to isolate viable islets. Most clinical islet transplant centers load the enzyme into the pancreas by retrograde injection using a syringe following cannulation of the pancreatic duct. An alternative approach is to perfuse the ...
Falck G - - 1999
Perturbations of the extracellular osmotic environment leads to cell volume changes. The aim of the present study was to evaluate the effects of hyperosmolality on cardiac contractile function and in particular the role of ionic mechanisms anticipated to be operative during hyperosmolal exposure. Paced rabbit hearts were perfused in the ...
Ozturk T - - 1999
Midazolam is known to cause a dose-dependent increase and decrease in the contractile force of the myocardium. Whether flumazenil can reverse these effects of midazolam remains unclear. In this study, we determined the cardiac effects of midazolam and the counter effect of flumazenil on midazolam-induced myocardial depression in isolated rabbit ...
Haugen G - - 1999
BACKGROUND: To investigate the vascular resistance and the vasoactive effects of serotonin in arteries from single umbilical artery (SUA) cords. METHODS: The preparations were sampled from 10 patients with SUA cords. The control group (n=20) was matched according to gestational age, birth weight percentile, blood pressure and proteinuria. The arterial ...
Befroy D E - - 1999
To determine the contribution of changes in extracellular osmolarity to ischemic injury, isolated guinea pig hearts were perfused with hyposmotic (220 mosM) or hyperosmotic (380 mosM) buffer. 31P NMR spectroscopy was used to follow changes in intracellular pH (pHi) and energetics. Hyposmotic buffer decreased myocardial developed pressure by 30 +/- ...
Schwerte T - - 1999
The effects of &bgr;-adrenergic stimulation, vasoactive intestinal polypeptide (VIP), adenosine, the nitric oxide (NO)-releasing agent sodium nitroprusside and of metabolic end-products of gas gland cell metabolism on swimbladder blood flow were investigated using saline- or blood-perfused swimbladder preparations of the freshwater European eel Anguilla anguilla. While &bgr;-adrenergic vasodilation was not ...
Herrman E C - - 1999
This study describes alterations in skin perfusion in response to step increases in surface pressure, before and after long-term (5 hr) exposure to pressure-induced ischemia. A provocative test was developed in which surface pressure was increased in increments of 3.7 mmHg until perfusion reached an apparent minimum by a computer-controlled ...
Meier-Hellmann A - - 1999
Adequate volume loading may be the most important step in the treatment of patients with septic shock. Techniques allowing us to achieve and tightly control volume loading and regional perfusion are considered to be helpful. An elevated oxygen delivery may be beneficial in some patients but the increase of oxygen ...
Ubbink D T - - 1999
In the treatment of distal esophageal pathology, surgical mobilization and exteriorization of the thoracic esophagus can be necessary. This may threaten its vascularization. We investigated the effect of longitudinal dissection and distal transsection on the microcirculatory perfusion of the canine esophagus. Esophageal perfusion and muscular oxygenation were investigated in 11 ...
Siaghy E M - - 1999
Microdialysis is an established technique for measuring the kinetics of various neurotransmitters within the extracellular space in the field of neurochemistry. Recently, its use has been extended to sampling in other tissues, including liver, kidney and the heart. A persistent problem in cardiac microdialysis concerns two parameters related to myocardial ...
Kromer B M - - 1999
1. 8-epi prostaglandin (PG) F2alpha, a vasoconstrictor isoprostane, is synthesized under conditions of oxidative stress. This study was undertaken to investigate the vasoconstrictor effect of 8-epi PGF2alpha in the coronary circulation before and after a period of oxidative stress. 2. The effects of the isoprostane 8-epi PGF2alpha and the thromboxane ...
Pilati P L - - 1999
Based on the premise that optimal drug delivery might improve the efficacy of locoregional treatment for solid tumors, the authors set up an experimental model for isolation perfusion in surgical specimens from patients resected for carcinoma of the colon. Ten surgical specimens were cannulated, washed internally and externally with saline ...
Belfort M A - - 1999
Eclampsia continues to be a major cause of maternal morbidity and mortality rates, especially in underdeveloped nations. Our data indicate that eclampsia may represent the end stage of at least two very different pathophysiological pathways: one in which cerebral perfusion is low because of vasospasm and another in which cerebral ...
Slovut D P - - 1999
A goal of clinicians caring for heart transplant recipients has been to use heart rate variability as a noninvasive means of diagnosing graft rejection. The determinants of beat-to-beat variability in the surgically denervated heart have yet to be elucidated. We used an isolated, blood buffer-perfused porcine heart preparation to quantitatively ...
Hermens F H - - 1999
The use of non-heartbeating (NHB) donor kidneys has led to the search for new methods of viability-testing. We investigated, in a canine model, the relationship between the filtration of dextran 12, 000 into urine and a certain period of warm ischemic time (WIT) during machine perfusion. Twenty-four canine kidneys were ...
Nazeyrollas P - - 1999
PURPOSE: To determine the effects of amifostine on an isolated perfused rat-heart model and its protective activity with regard to cardiotoxic doxorubicin perfusion. METHODS: Langendorff constant-pressure isolated rat-heart preparations were used to analyze the effects of the drugs during a 40-min period of perfusion after a 20-min stabilization interval. The ...
Sato Y - - 1999
This study was undertaken to investigate the neurological risk factors associated with the retrograde cerebral perfusion (RCP) technique, by examining the relationship between intraoperative parameters and post-operative brain complications. A total of 12 patients who underwent surgery for thoracic aortic aneurysms using the RCP technique were included in this study. ...
Edmunds N J - - 1999
1. The cardiac depressant actions of TNF were investigated in the isolated perfused rat heart under constant flow (10 ml min(-1)) and constant pressure (70 mmHg) conditions, using a recirculating (50 ml) mode of perfusion. 2. Under constant flow conditions TNF (20 ng ml(-1)) caused an early (< 25 min) ...
Traynor T - - 1998
The effect of the adenosine type 1 receptor agonist N6-cyclohexyladenosine (CHA) on glomerular vascular reactivity was studied in male angiotensin II type 1A (AT1A) receptor knockout mice (9). Vascular reactivity was assessed as the response of stop-flow pressure (PSF) to infusion of CHA into loops of Henle using micropuncture techniques. ...
Wu J - - 1998
INTRODUCTION: Cytochalasin D in tissue bath superfusate inhibits the contraction of isolated thin trabeculae from canine right ventricle without affecting the intracellular action potential recorded with glass microelectrode. The purpose of this study was to test whether cytochalasin D could also be used to immobilize perfused wedges of ventricular muscle ...
Cheng Y - - 1998
Voltage-sensitive dyes and imaging techniques have proved to be indispensable tools for use in in vitro electrophysiological studies. To avoid motion artifacts in optical recordings, electromechanical uncouplers such as 2,3-butanedione monoxime (BDM) are required. In this study, we sought to determine whether the voltage-sensitive dye RH421 had an effect on ...
Hoover D B - - 1998
Goals of this study were to identify and characterize effects of neurokinin A (NKA) in isolated guinea pig hearts. Bradycardia, augmentation of ventricular contractions, and reduction of perfusion pressure were prominent responses to bolus injections of NKA (0. 25-25 nmol). NKA was more potent than substance P (SP) in causing ...
Altemeier W A - - 1998
To explore mechanisms of hypoxemia after acute pulmonary embolism, we measured regional pulmonary blood flow and alveolar ventilation before and after embolization with 780-micrometers beads in five anesthetized, mechanically ventilated pigs. Regional ventilation and perfusion were determined in approximately 2.0-cm3 lung volumes by using 1-micrometers-diameter aerosolized and 15-micrometers-diameter injected fluorescent ...
Noble B J - - 1998
1. In chloralose-anaesthetized, artificially ventilated dogs, the splenic pedicle was tied and the carotid sinuses were vascularly isolated and perfused at controlled pressures. In Series 1 experiments, the hepatosplanchnic circulation was perfused through the abdominal aorta with a tie on the aorta separating it from the caudal circulation, which was ...
Gök S - - 1998
The effect of a leukotriene D4 (LTD4) receptor antagonist, L-648,051, was investigated in digoxin-induced cardiac toxicity in isolated guinea-pig hearts (Langendorff preparation). Digoxin infusion (25 microg.ml-1, 0.5 ml.min-1) increased perfusion pressure and contractile force initially, but decreased them later. The onset of first ventricular premature beats (VPBs) matched the increase ...
de Curtis M - - 1998
We describe a new method for studying the interactions between vascular tone changes and neuronal activity in the arterially perfused isolated brain of the adult guinea pig maintained in vitro. Electrophysiological recordings were performed in the piriform and entorhinal cortices with the entire arterial bed preserved or after vascular restriction ...
Kunst P W - - 1998
Electrical impedance tomography (EIT) is a technique that makes it possible to measure ventilation and pulmonary perfusion in a volume that approximates to a 2D plane. The possibility of using EIT for measuring the left-right division of ventilation and perfusion was compared with that of radionuclide imaging. Following routine ventilation ...
Sielenkämper A W - - 1998
Interruption of patent ductus arteriosus (PDA) using video-assisted thoracoscopic surgery (VATS) has recently been introduced into clinical practice. To study cardiovascular and pulmonary function during VATS, we treated 16 newborn pigs (weight 1421+/-44 g) with PDA with conventional surgical interruption (CSI; n = 7) or interruption via VATS (n = ...
Nowicki P T - - 1998
Studies were conducted to determine the effect of mechanically induced sustained flow reduction on intestinal hemodynamics and oxygenation in 3- and 35-day-old swine. In vitro gut loops were perfused under controlled-pressure conditions from an oxygenated blood reservoir at age-appropriate perfusion pressures; pressure was rapidly reduced to a level that lowered ...
Wen J G - - 1998
PURPOSE: To create an animal model with mild and severe partial unilateral ureter obstruction in young rats using a modified Ulm and Miller technique and to characterize the model by acute renal pelvic pressure measurements. MATERIAL AND METHODS: During anesthesia the upper fourth (n = 15) or the upper two-thirds ...
Okazaki K - - 1998
1. We examined the vasodilatory effect of hypercapnia in the rat isolated mesenteric vascular bed. The preparation was perfused constantly (5 ml min(-1) with oxygenated Krebs-Ringer solution, and the perfusion pressure was measured. In order to keep the extracellular pH (pHe) constant (around 7.35) against a change in CO2, adequate ...
Newman J M - - 1998
Angiotensin (AII) and serotonin (5-HT) are both vasoconstrictors of the constant-flow perfused rat hind limb that have opposite effects on thermogenesis, possibly the result of differing effects on vascular flow distribution between nutritive and non-nutritive pathways. In the present study interaction between the two opposing agents was examined with the ...
Osaki J - - 1998
BACKGROUND: Production of heat shock protein 70 (HSP70) in the heart is induced by hemodynamic stress, but its intracellular signal transduction system has not been elucidated well. OBJECTIVE: To investigate the hypothesis that protein kinase A (PKA)-dependent and protein kinase C (PKC)dependent systems are involved in the pressure-induced expression of ...
Lohman R - - 1998
Cardiac output (CO) is redistributed during hypovolemia, but it has not been clearly documented how this influences flap perfusion. Simultaneous changes in perfusion of a muscle flap and CO as modulated by reductions in cardiac filling pressure were compared in a pig model. The hypothesis was that flap flow (FF) ...
Cannan C R - - 1998
The perfusion sleeve (PS) is an "over-the-balloon" catheter designed to add perfusion capability to standard PTCA catheters. To evaluate the clinical effectiveness of this device, eight patients underwent standard PTCA with the PS retracted in the guide (Inflation 1-Control) and after deployment of the PS (Inflation 3-Control). Between standard inflations ...
Fujita S - - 1998
OBJECTIVE: The aims were to validate the use of a direct reading NO electrode, to compare the effects of diverse acting drugs on altering coronary flow (CF) and NO release, and to examine the effects of altered perfusion pressure on flow-induced changes in NO concentration [NO] in the hemoglobin free ...
Chen W H - - 1998
Perfused micromanometric assemblies with an outer diameter of 2 mm or less have been developed for use in premature infants and small laboratory animals. Such assemblies offer advantages with regard to subject comfort and low perfusion rates that make them attractive for use in adults. The aim of this study ...
Alexander B - - 1998
It is unclear how the omission of a perfusate oxygen carrier may influence data derived from prolonged in vitro liver perfusions. The effects of reduced perfusate oxygen content upon liver function tests conducted in livers from male Sprague-Dawley rats perfused for 6 h, were studied using diluted rat blood (PCV ...
Mc Parland B E - - 1998
In vivo agonist delivery to the lungs is characterized by absorption through the mucosal layer followed by access to the smooth muscle. When agonists are applied to perfused bronchial segments, a difference in potency to agonists applied to the serosal (outside) or mucosal (inside) surface can be demonstrated. In order ...
Ay I - - 1998
1. In isolated perfused rat kidney, under a constant flow of 8-10 ml/min, mean basal perfusion pressure was found to be 82.57 +/- 8.96 mm Hg (n = 70). 2. After a bolus injection of 10 micrograms/0.1 ml phenylephrine (PE) which causes maximum vasopressor response, a 93.27 +/- 0.56 mm ...
Samsom M - - 1998
The development of solid-state catheters with miniature pressure transducers and portable dataloggers with a large memory capacity has allowed recording of gastrointestinal motility in ambulant subjects. Developments in silicone rubber extrusion technology made it possible to build a perfused manometric system, using a perfused manometric assembly requiring a low volume ...
Pintér A - - 1998
Vasoactive intestinal polypeptide (VIP) was either injected intravenously (300 pmol.kg-1) or perfused (1 nmol in 1 min) into the sinus node artery (SNA) in anesthetized dogs to study its effect on subsidiary atrial pacemakers. Isochronal maps were obtained from 128 unipolar electrograms recorded on the epicardial surface of both atria ...
Kleen M - - 1998
Hypervolaemic haemodilution makes myocardial perfusion more homogenous as reflected by reduced fractal dimension of regional myocardial perfusion. The clinically more commonly performed acute normovolaemic haemodilution, however, has not yet been studied in this respect. Hyperoxic ventilation with 100% oxygen is used in conjunction with haemodilution to compensate for low oxygen ...
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