Search Results
Results 451 - 500 of 1598
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Bennett Lee Ann T - - 2003
Active vasodilatation (AVD) in human, non-glabrous skin depends on functional cholinergic fibres but not on acetylcholine (ACh). We tested whether AVD is a redundant system in which ACh and vasoactive intestinal polypeptide (VIP) are co-released from cholinergic nerves. (1) We administered VIP by intradermal microdialysis to four discrete areas of ...
Holst U - - 2003
PURPOSE: We evaluated the effects of norepinephrine on transport pressures in the normal upper urinary tract of the pig during increasing perfusion rates. MATERIALS AND METHODS: Anesthetized Danish landrace Yorkshire pigs weighing 38 to 40 kg were studied. Transparenchymally 2, 6Fr catheters were introduced into the left renal pelvis for ...
Carvajal Karla - - 2003
The metabolic pathways involved in ATP production in hypertriglyceridemic rat hearts were evaluated. Hearts from male Wistar rats with sugar-induced hypertriglyceridemia were perfused in an isolated organ system. Mechanical performance, oxygen uptake and beat rate were evaluated under perfusion with different oxidizable substrates. Age- and weight-matched animals were used as ...
Daley Joseph C JC - - 2003
The purpose of this study was to examine hemodynamic responses to graded muscle reflex engagement in human subjects. We studied seven healthy human volunteers [24 +/- 2 (SE) yr old; 4 men, 3 women] performing rhythmic handgrip exercise [40% maximal voluntary contraction (MVC)] during ambient and positive pressure exercise (+10 ...
Myers Gerard J - - 2003
The occurrence of sudden increases in premembrane pressures and membrane pressure differentials has drawn considerable attention and debate in the perfusion community. Several terms have been applied to this phenomenon, but the term that best describes this event is "high-pressure excursion" (HPE). The exact causes of HPE are still uncertain, ...
Mayrovitz Harvey N - - 2003
OBJECTIVE: To investigate the effect of pressure-relief magnitude on heel blood flow. DESIGN: 12 healthy subjects (5 male, 7 female; 21 to 43 years of age) lay on a support surface for 50 minutes with 1 heel on the end cell of the support surface. Cell pressure was computer controlled ...
Nogueira Ana Cristina - - 2003
The aim of this study was to characterize functional parameters in the isolated and normothermic hemoperfused porcine beating heart model after pathophysiological stimuli for extended perfusion periods. Hearts were prepared and connected to a specially developed perfusion equipment, which simultaneously allowed perfusion with warm autologous blood as well as blood ...
Lisbon Alan - - 2003
Inadequate splanchnic perfusion in the critically ill compromises the gut barrier leading to bacterial translocation, which is postulated to cause multiorgan dysfunction and failure. Inotropic agents such as dopexamine, dobutamine, and dopamine may have a role in increasing splanchnic perfusion, thereby protecting this area from further injury. This article examines ...
Ruffolo Daria C - - 2003
Adequate tissue oxygenation is one of the main therapeutic goals for the critically ill patient. Until recently, the perfusion status of the critically ill and injured has been assessed by global indices such as blood pressure, heart rate, and urine output. However, these global parameters are inadequate in that they ...
Jones A T - - 2003
Patients with acute lung injury may benefit from the manipulation of pulmonary blood flow using inhaled nitric oxide (iNO) to optimise ventilation/perfusion matching. Current techniques for studying changes in regional pulmonary perfusion are difficult to apply clinically. This study therefore investigated the potential of electron-beam computed tomography (EBCT) to quantify ...
Ergün Eser Lay - - 2003
The most common indication for radionuclide imaging of lungs is the evaluation of suspected pulmonary thromboembolism (PE). Scintigraphically PE classically produces ventilation/perfusion mismatch, that is perfusion defects in areas showing normal ventilation. Stripe sign refers to the visualization a stripe at normally perfused lung interposed between a defect and adjacent ...
Wiechert S - - 2003
The human genome project has increased the demand for simple experimental systems that allow the impact of gene manipulations to be studied under controlled ex vivo conditions. We hypothesized that, in contrast to adult hearts, neonatal hearts allow long-term perfusion and efficient gene transfer ex vivo. A Langendorff perfusion system ...
Tanen David A - - 2003
STUDY OBJECTIVE: Crotalidae Polyvalent Immune Fab (CroFab; FabAV) antivenom prevents a decrease in perfusion pressures in intramuscular crotaline envenomation compared with normal saline solution. METHODS: We used a randomized, blinded, controlled acute animal preparation. Twenty anesthetized and instrumented swine were injected intramuscularly with 6 mg/kg Crotalus atrox venom into the ...
Moench Christian - - 2003
Ischemic-type biliary lesions (ITBLs) lead to considerable morbidity after orthotopic liver transplantation (OLT). The exact pathogenesis is unknown. We tested the hypothesis that insufficient perfusion of biliary arterial vessels might be responsible for ITBLs. This could be prevented by improved perfusion techniques. Since February 2000, we performed a controlled study ...
de Assis Gabriela Poltronieri Souza - - 2003
Personal exposure to mercury vapor and the release of mercury from or during removal of amalgam dental fillings increases its blood and plasma concentration. However, it is not known if these very small amounts affect cardiac function. The effects of continuous exposure to 5 and 20 nM of HgCl(2) on ...
Zuurbier Coert Jozef - - 2003
The main goal of the study was to examine how the microsphere technique affects the hemodynamics and mitochondrial energy status of the Langendorff-perfused rat heart. The hearts were perfused at a constant flow with Tyrode solution. NADH videofluorometry of the surface of the left ventricle was used to record the ...
Schinkel Arend F L - - 2003
Because of damage to cardiomyocytes and the contractile apparatus, contractile reserve may be observed less frequently in hibernating than in stunned myocardium. The aim of this study was to assess the presence of contractile reserve in response to dobutamine infusion in a large group of patients with stunned and hibernating ...
Kaygisiz Z - - 2003
The effect of human adrenomedullin, human amylin fragment 8-37 (amylin 8-37) and rat calcitonin gene-related peptide (CGRP) on contractile force, heart rate and coronary perfusion pressure has been investigated in the isolated perfused rat hearts. Adrenomedullin (2x10(-10), 2x10(-9) and 2x10(-8) M) produced a significant decrease in contractile force and perfusion ...
Mühling Olaf M - - 2003
OBJECTIVE: It is controversial whether transmyocardial laser revascularization (TMLR) improves myocardial perfusion. Therefore, we assessed myocardial perfusion before and after TMLR with quantitative magnetic resonance perfusion imaging (MRPI) in an animal study. METHODS: One week after partial occlusion of the left circumflex artery (LCx) in 12 pigs, resting perfusion (ml/g/min), ...
Bendjelid K - - 2003
BACKGROUND: The dissociation of mechanical from non-mechanical energy utilisation can be studied using BDM (2,3-butanedione monoxime), which inhibits the actin-myosin interaction without inhibiting Ca2+ transport. The objective of the present study was to establish if increasing the non-mechanical energy demand of perfused isolated pig hearts by dobutamine stimulation requires glycolysis ...
Yoshida Shoji - - 2002
OBJECTIVE: The purpose of this study is to investigate the physiological pulmonary perfusion pattern in different respiratory phases by calculating the normalized volume center of perfusion intensity. METHODS: Four nonsmoking volunteers underwent single photon emission computed tomography (SPECT) of maximum inspiration and expiration after the injection of Tc-99m-MAA in each ...
Király László - - 2002
AIM: To present our experience with modified cannulation with continuous, moderately hypothermic systemic perfusion in extensive aortic arch repair. The technique has fewer complications and preserves cerebral blood flow autoregulation. METHOD: Nine neonates, 6 with the hypoplastic left heart syndrome and 3 with the interrupted aortic arch with ventricular septal ...
Lee Charles Y - - 2002
BACKGROUND: Hypothermic machine perfusion preservation has the potential to relieve the current donor shortage problem by reclaiming and preserving marginal donor organs including those from viable non-heart-beating donors. A number of problems exist with the current machine perfusion technology for preserving livers, and much research is needed to determine the ...
Zimmer Heinz-Gerd - - 2002
In 1866 at Carl Ludwig's Physiological Institute at Leipzig, Elias Cyon described the influence of diastolic filling of the isolated perfused frog heart on ejection volume. A study performed at the institute of the effect of filling pressure on contraction amplitude was published in 1869 by Joseph Coats, based on ...
Kellogg D L DL - - 2002
To test the hypothesis that bradykinin effects cutaneous active vasodilation during hyperthermia, we examined whether the increase in skin blood flow (SkBF) during heat stress was affected by blockade of bradykinin B(2) receptors with the receptor antagonist HOE-140. Two adjacent sites on the forearm were instrumented with intradermal microdialysis probes ...
Bax Jeroen J - - 2002
BACKGROUND: Chronic dysfunctional but viable myocardium may exhibit contractile reserve and/or intact perfusion. Segments with intact perfusion without contractile reserve are frequently observed inpatients with ischemic cardiomyopathy. The clinical relevance of this observation is unclear; in particular, the functional outcome after revascularization is unknown. Thus, contractile reserve (using low-dose dobutamine ...
Brunsden A M - - 2002
Using novel in vitro preparations of vascularly perfused rat ileum, we investigated mesenteric afferent sensitivity to vascular perfusion. Gut (GPP) and vascular (VPP) perfusion pressures were recorded simultaneously with afferent discharge (AD). After preconstriction (L-phenylephrine), capsaicin (100 microM, gut lumen) caused a transient increase in AD and a sustained fall ...
Bainbridge S A - - 2002
Carbon monoxide (CO) is one of the metabolites formed via heme oxidation catalysed by the enzyme heme oxygenase (HO). Endogenous formation of CO, mediated by HO, has been noted in both placental and umbilical vessels. In blood vessels from different mammalian sources, it has been proposed that the vasodilator effect ...
Zeitlin I J - - 2002
It has been postulated that the mammary kinin system may play a role in modulating mammary blood flow. Until the present study, the local release of bradykinin (BK) or other kinin system constituents into the mammary vasculature had not been reported and there were also conflicting findings on the action ...
Wang Q-D - - 2002
During the development of a Langendorff preparation of isolated mouse hearts, hitherto undescribed cyclic fluctuations in left ventricular pressure and coronary flow were independently observed in three laboratories. Isolated mouse hearts were perfused with crystalloid glucose-containing Krebs-Hensleit buffer in a constant pressure model, and left ventricular pressures were measured via ...
Bilston Lynne E - - 2002
Some simple finite element models were constructed to investigate the magnitude and character of changes in mechanical properties of very soft tissues due to the loss of perfusion. Changes in the apparent stress-strain curve were used to characterise the effect of simulated blood perfusion pressure on the engineering stress-strain curve. ...
Fisher David - - 2002
In this study the effects of perfusing isolated seminiferous tubules of the testes are reported for the first time. Initial perfusion studies (fast rate perfusion) resulted in gross morphological damage to the seminiferous tubules. The recorded transepithelial potential (V(t)) was close to 0 mV. Slow perfusion rates eliminated morphological damage ...
Mayrovitz Harvey N - - 2002
OBJECTIVE: It was hypothesized that a device or support surface providing intermittent cycles of pressurization and pressure relief might minimize the impact of blood flow deficits in the heels resulting from the application of pressure. Because this possibility depends on whether pressure-relief hyperemia can adequately compensate for blood flow deficits, ...
Parra Augusto - - 2002
The transgenic mouse has been used to study subarachnoid hemorrhage (SAH) induced delayed cerebral vasospasm (DCV). Methodological parameters have not been analyzed to validate this model and associated neurological deficits have not been described. We introduce a technique to quantify DCV and associated neurological deficits. C57BL/6J mice were subjected to ...
Graf Bernhard M - - 2002
BACKGROUND: Ropivacaine is believed to have a lower incidence of clinical cardiac side effects than bupivacaine. The aim of this study was to compare the direct cardiac effects of the optically pure S(-)-ropivacaine isomer and its nonclinically used R(+)-isomer with both optically pure bupivacaine isomers in isolated hearts. The hypothesis ...
Sack F U - - 2002
BACKGROUND: Cardio-thoracic surgery with the use of extracorporeal circulation may lead to an impairment of splanchnic perfusion. The aim of this study was to investigate the effect of dopexamine on gastrointestinal microvascular perfusion failure due to extracorporeal circulation. METHODS: Twenty landrace pigs served as laboratory animals. A loop of the ...
Lima Alexandre Pinto - - 2002
OBJECTIVE: Peripheral perfusion in critically ill patients frequently is assessed by use of clinical signs. Recently, the pulse oximetry signal has been suggested to reflect changes in peripheral perfusion. A peripheral perfusion index based on analysis of the pulse oximetry signal has been implemented in monitoring systems as an index ...
Tolstykh Gleb P - - 2002
BACKGROUND: Technology that can implement the basic requirements for successful organ preservation in a portable configuration has yet to be realized. METHODS: This work evaluates kidney preservation in a new class of portable organ preservation technology based on fluidics principles. During hypothermic pulsatile perfusion preservation (HPPP), oxygen consumption, renal vascular ...
Victorino Gregory P - - 2002
BACKGROUND: The effect of hypertonic saline (HS) on microvascular permeability is unclear. We hypothesized that varying degrees of tonicity and HS solutions alter microvascular fluid flux across the endothelium. METHODS: Hydraulic permeability (L(p)) is a measure of water flow across the endothelial barrier. L(p) was measured in cannulated rat mesenteric ...
Moriya Toshihiro - - 2002
We are developing an original nonroller extracorporeal circulation system (NRECC). However, this NRECC could not perform selective cerebral perfusion (SCP). Therefore, we added cerebral perfusion lines and an automatic pressure controller to the system. The purpose of this study was to evaluate the stability and response of the pressure controller ...
Fulep Eva E - - 2002
OBJECTIVE: Our purpose was to study the effects of inhibition of nitric oxide synthesis on perfusion pressure and flow rate-perfusion pressure relationships in the rat uterine circulation in situ. STUDY DESIGN: Nonpregnant, midpregnant (day 14), and late pregnant (day 21) Sprague-Dawley rats were studied. The vascular bed of the intact ...
Hoff Tracy K - - 2002
OBJECTIVE: To evaluate the clinical efficacy of topically administered glyceryl trinitrate (GTN) for inducing digital submural vasodilation in clinically normal horses. ANIMALS: 7 adult horses without foot abnormalities. PROCEDURES: A concurrent-control crossover design was used to determine whether topical application of GTN ointment for prevention or treatment of laminitis would ...
Haugen Guttorm - - 2002
BACKGROUND: Pregnancy is feasible in organ-transplanted women, but little is known about possible effects of ciclosporine A on the circulation in the fetus and placenta. AIM: To investigate the influence of ciclosporine A (CsA) on the vasoactive effects of serotonin in human umbilical arteries. STUDY DESIGN AND SUBJECTS: In vitro ...
Demiryürek A Tuncay - - 2002
Reactive oxygen species, generated and released during digoxin-induced cardiotoxicity, can produce an activation of poly (ADP-ribose) synthase (PARS). Our objective was to examine the effects of PARS inhibitors, 3-aminobenzamide (3-AB ) and nicotinamide, on digoxin-induced arrhythmias in guinea-pig isolated hearts. 3-AB (0.1-0.3 mM) and nicotinamide (0.3 mM) were added to ...
Pakulski Cezary - - 2002
BACKGROUND: The aim of our research was to evaluate the influence of general anesthesia with controlled nitroglycerin-induced hypotension on splanchnic mucosal perfusion using gastric tonometry. MATERIAL/METHODS: In six patients (1 female, 5 males, median age 46 years, range 32-62) undergoing elective resection of meningiomas, measurements of gastric mucosal perfusion were ...
Walsh Edward G - - 2002
Myocardial perfusion imaging using Gd contrast agents is typically performed with bolus injections of the contrast agent using a power injector to provide for consistent and sufficiently rapid injection rates for all patients. For protocols in which a peripheral venous injection is called for (e.g. antecubital vein) injection catheters of ...
Hirose Satoshi - - 2002
We previously successfully developed a simple nonroller extracorporeal circulation system (NRECC). In aortic arch surgery, more than two pumps are generally used for systemic perfusion and selective cerebral perfusion (SCP); we developed a new pressure-dependent perfusion system for SCP based on our NRECC and operated by a single centrifugal pump. ...
Hamrin K - - 2002
Microdialysis catheters (CMA-60 with a polyamide dialysis membrane; 20,000-molecular wt cutoff) were either immersed in an external medium or were inserted in the quadriceps femoris muscle of healthy subjects, using perfusate with or without dextran 70. Varying the position of the outflow tubing induced changes in hydrostatic pressure. The sample ...
SkoczyƄski M - - 2001
Increased systemic vascular resistance and blood pressure during pregnancy may be due to impaired prostacycline PGI(2)-thromboxan (TX) A(2) balance. The aim of the study was to compare the influence of magnesium sulphate and isradipine on the placental vascular resistance induced by stable thromboxan A(2) analogue U 46619 in experimental bilateral ...
Hartman J M - - 2001
OBJECTIVES: To correlate supraclavicular left internal mammary artery (LIMA) to left anterior descending artery (LAD) area Doppler characteristics with angiographically perfused area. METHODS: Sixty patients (50 male, mean age 62+/-7.3 years) with LIMA to LAD area grafting were prospectively entered in a follow up study. Supraclavicular echo Doppler of the ...
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