Search Results
Results 351 - 400 of 1598
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Rider Alan R - - 2007
Multiple factors influence the outcome of cardiopulmonary bypass (CPB) procedures in pediatric patients with congenital heart defects. The benefit of pulsatile over nonpulsatile perfusion is one such factor that continues to be widely debated among researchers, perfusionists, and surgeons. However, by accurately measuring pulsatile flow in terms of energy equivalent ...
Thomas G - - 2008
To perform an empirical, pharmacological, separation of early afterdepolarizations (EADs) and transmural gradients of repolarization in arrhythmogenesis in a genetically modified mouse heart modelling human long QT syndrome (LQT) 3. Left ventricular endocardial and epicardial monophasic action potentials and arrhythmogenic tendency were compared in isolated wild type (WT) and Scn5a+/Delta ...
Legros E - - 2007
Calcitonin gene-related peptide (CGRP), a capsaicin-sensitive neuromodulator of splanchnic vascular tone in several animal species, remains poorly investigated in mouse models. We therefore assessed whether endogenous CGRP is a non-adrenergic/non-cholinergic (NANC) neuromodulator in the mesenteric vascular bed of the mouse. Arterial and venous changes in perfusion pressure in response to ...
Zhao Fang - - 2007
To explore the role of mechanosensitive potassium channel TREK-1, Western blot analysis was used to investigate the expression changes of TREK-1 in left ventricle in acute mechanically stretched heart. Forty Wistar rats were randomly divided into 8 groups (n=5 in each group), subject to single Langendorff perfusion for 0, 30, ...
Wang Xuemei - - 2007
Recent studies of renal autoregulation have shown modulation of the faster myogenic mechanism by the slower tubuloglomerular feedback and that the modulation can be detected in the dynamics of the myogenic mechanism. Conceptual and empirical considerations suggest that perfusion pressure may modulate the myogenic mechanism, although this has not been ...
Wakita Yoshiakira - - 2007
Some improvements of Kodama's method for perfusing the isolated rabbit heart in its working mode were made. Increases in the right and left atrium pressure, together with an increase in the pulmonary artery pressure, were observed to occur immediately after the start of venous return, and then all of the ...
Jeong Woo Won - - 2007
Dissolution of a blood clot in thrombolytic procedure is affected by permeation of a thrombolytic agent into a clot, and permeation of plasminogen activator into a clot is dependent on the permeation pressure. A controlled experimental study on the effects of permeation pressure on clot lysis was carried out. The ...
Jakobsen J S - - 2007
PURPOSE: Isoproterenol (Sygehus Apotekerne Danmark, Copenhagen, Denmark) is a beta-adrenergic agonist known to cause upper urinary tract relaxation. We studied the local effect on pelvic pressure and the systemic effects of endoluminal perfusion with isoproterenol in a porcine model. MATERIALS AND METHODS: Pigs weighing 40 kg were studied. Catheters were ...
Zhang Shuijun S Department of Surgery, First Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China, - - 2007
It remains controversial that after the transplantation of using grafts from brain-dead donors, organs injury and rejection can influence the effects of transplantation. This study sought to explore methods of establishing a stable brain death (BD) model using Bama mini pigs and to maintain the brain-dead state for a comparatively ...
Stowe David F - - 2007
There is no suitable solution to preserve hearts for longer than 5 h between donor explant and recipient implant. Lifor is a fully artificial preservation medium containing both a nonprotein oxygen and nutrient carrier (nanoparticles) and cellular nutrients, including amino acids and sugars. We proposed that recirculated Lifor solution would ...
Vespa Paul M - - 2007
OBJECTIVE: To determine whether pericontusional tissue exhibits neurochemical responsiveness to changes in cerebral perfusion pressure as measured by microdialysis lactate/pyruvate ratio. DESIGN: Prospective monitoring with retrospective data analysis. SETTING: Single-center academic neurologic intensive care unit. PATIENTS: Twenty-one patients with severe traumatic brain injury (Glasgow Coma Scale score 3-8). INTERVENTIONS: None. ...
't Hart Nils A - - 2007
Hypothermic machine perfusion (HMP) provides better protection against ischemic damage of the kidney compared to cold-storage. The required perfusion pressures needed for optimal HMP of the liver are, however, unknown. Rat livers were preserved in University of Wisconsin organ preservation solution enriched with acridine orange (AO) to stain viable cells ...
Lentle Roger G - - 2007
Longitudinal and radial movements during spontaneous contractions of isolated segments of terminal ileum of the brushtail possum, a species of arboreal folivore, were studied using high definition spatiotemporal maps. Segments obtained from specimens were continuously perfused with solutions of various apparent viscosities at 3 cm and 5 cm hydrostatic pressure. ...
Pocar Marco - - 2007
BACKGROUND: Spinal cord damage represents a devastating complication of thoracic and thoracoabdominal aortic surgery. Retrograde perfusion as an alternative route to protect the spinal cord has recently been investigated with controversial results. We reviewed the literature and analyzed additional experimental observations. METHODS: Ten juvenile pigs were divided into control and ...
Daniel Stamer W W Department of Ophthalmology, The University of Arizona, Tucson, AZ, USA. - - 2007
The goal of the present study was to specifically modify protein expression in the resistance-generating region of the conventional outflow pathway, namely the inner wall of Schlemm's canal (SC) and the juxtacanalicular region of the trabecular meshwork, in perfused human anterior segments. Anterior segments from human cadaveric eyes were prepared ...
Moench C - - 2007
Effective preservation of liver grafts is the first essential step for successful liver transplantation. Insufficient perfusion leads to ischemic-type biliary lesions after transplantation. Perfusion of the graft can be performed either in situ or ex situ, with gravity flow or pressure-controlled. Mainly University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) solutions ...
Bodlaj Gerd - - 2007
BACKGROUND: Arterial stiffness is thought to play a critical role in the pathogenesis of cardiovascular events, and in hyperthyroidism increased cardiovascular event rates have been reported. AIM: To investigate markers of systemic arterial stiffness, volume homeostasis, and subendocardial perfusion and its interrelationship in patients with Graves' disease (GD) in hyperthyroidism ...
O'Connor Paul M - - 2007
Recently, a combined probe has been developed capable of simultaneous measurement of local tissue pO2 (fluorescence oximetry) and microvascular perfusion (laser Doppler flux) within the same local region. The aim of the current study was to test the utility of these combined probes to measure pO2 and perfusion in the ...
Killeen M J MJ Physiological Laboratory, University of Cambridge, Cambridge, UK. - - 2007
Hypokalaemia is associated with a lethal form of ventricular tachycardia (VT), torsade de pointes, through pathophysiological mechanisms requiring clarification. Left ventricular endocardial and epicardial monophasic action potentials were compared in isolated mouse hearts paced from the right ventricular epicardium perfused with hypokalaemic (3 and 4 mm [K(+)](o)) solutions. Corresponding K(+) ...
Makhsous Mohsen M Department of Physical Therapy and Human Movement Sciences, Northwestern University, 645 N. Michigan Avenue, Suite 100, Chicago, IL 60640, USA. - - 2007
To study the effect on tissue perfusion of relieving interface pressure using standard wheelchair pushups compared with a mechanical automated dynamic pressure relief system. Repeated measures in 2 protocols on 3 groups of subjects. Twenty individuals with motor-complete paraplegia below T4, 20 with motor-complete tetraplegia, and 20 able-bodied subjects. Two ...
McCarty William J WJ Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, - - 2007
In this study, we measured the specific hydraulic conductivity (K) of Matrigel at 1% and 2% concentrations as a function of perfusion pressure (0 to 100 mmHg) and compared the results to predictions from two models: a fiber matrix model that predicted K of the gel based upon its composition, ...
Wei Hua - - 2006
It is necessary to control the mechanical stimuli precisely in the studies of cardiac mechano-electrical feedback (MEF). In the present study a ventricular pressure-clamping system has been developed, which can be applied to isolated-perfused rabbit hearts. Controlled by a computer, this system not only can make the left ventricle follow ...
Yang Yanmin - - 2006
This study was undertaken to determine the effects of different pH management strategies during retrograde cerebral perfusion on the relationship between retrograde perfusion pressure and brain tissue perfusion. Six pigs were subjected to an alpha-stat strategy and another 6 to a pH-stat strategy during hypothermic (15 degrees C) retrograde cerebral ...
Bonvalot S - - 2007
BACKGROUND: Isolated pelvic perfusion exposes tissue to high drug doses and may benefit patients with advanced malignancy. However, leakage is a limit to this technique. AIMS: The aim of the study is to increase the perfusion ratio between local and systemic compartments on isolated pelvic perfusion. We hypothesised that an ...
Smolenski Ryszard T RT Heart Science Centre, Imperial College at Harefield Hospital, Harefield, Middlesex, UB9 6JH, - - 2007
The use of pig hearts can solve the problem of shortage of donor hearts for transplantation. However, targeting rejection by single genetic modification was proven to be ineffective, highlighting the requirement for complex genetic modifications and more effective methods for transgenic animal production. We evaluated here whether hearts of hDAF ...
Yang Luojia - - 2006
This study was carried out to determine if increased perfusion pressure during retrograde cerebral perfusion (RCP) provides better preservation of the brain Na+, K+-ATPase activity. Twenty pigs were subjected to anesthesia alone (control group, n=5), hypothermic circulatory arrest (HCA) (HCA group, n = 5), HCA+RCP at perfusion pressures of 24-29 ...
Lauten Alexander - - 2007
Cardiopulmonary bypass (CPB) is a standard technique in cardiac surgery, which itself contributes to postoperative morbidity. Neurologic sequelae after CPB is caused by air embolism or systemic inflammatory response due to artificial surface and is closely related to the characteristics of the extracorporeal circuit. Minimized systems without a venous reservoir ...
Ritter Christian - - 2006
The prebolus technique allows one to quantify perfusion in the human heart with a low variability by means of MRI. In this study the prebolus technique was used to determine quantitative perfusion values in the human heart under adenosine stress and to measure the myocardial perfusion reserve (MPR). Twelve healthy ...
Altunkaya Aykut - - 2006
We examined the role of the nitric oxide (NO) pathway on ischemia-reperfusion injury via the use of isolated perfused guinea pig lungs. We administered both L-Arginine and N-nitro-L-arginine methyl ester (L-NAME) to the lungs in or after 3 h of ischemia. We observed pulmonary artery pressures as well as tissue ...
Lévy Bernard - - 2006
Experimental and clinical studies have established a link between end-organ damage in hypertensive patients and the severe impairment of tissue perfusion and microcirculation structure and function. Microvascular rarefaction is constantly observed in hypertension, and probably contributes to higher systemic resistance and lower tissue perfusion. Endothelial dysfunction leading to impaired arteriolar ...
Paonessa Damian J - - 2006
OBJECTIVE: This study was undertaken to determine whether 17-hydroxyprogesterone caproate (17P) has a vasoactive effect on fetoplacental vasculature. STUDY DESIGN: Two cotyledons were obtained from each of 5 placentas. Baseline perfusion was established with Hanks-based solution. One cotyledon from each pair was then infused with perfusate to which U46619 a ...
Bessems M - - 2006
For many years, the isolated perfused rat liver (IPRL) model has been used to investigate the physiology and pathophysiology of the rat liver. This in vitro model provides the opportunity to assess cellular injury and liver function in an isolated setting. This review offers an update of recent developments regarding ...
Mueller Andreas - - 2006
Adequate uterine contractility and periovulatory peristalsis, interpreted as "rapid sperm transport" to the side bearing the dominant follicle, may be a precondition for successful reproduction in humans. Estrogen and progesterone fluctuate characteristically during the menstrual cycle, and their source is the dominant follicle and corpus luteum. The question is, how ...
Soltan Ahmed Ebrahimi and ...
The isolated perfused rat kidney experiment was introduced in 1959 for studying the regulation of renal blood flow and is recognized as a valuable preparation for studying physiological and biochemical aspects of renal function such as hemodynamics, glomerular filtration rate (GFR) and overall handling of fluids. Dose-response curves are obtained ...
Murray A K - - 2006
OBJECTIVE: To investigate the hypothesis that cutaneous microvascular perfusion of the dorsum of the hand (in response to local heating) and distal phalanx (in response to occlusion) is impaired in patients with systemic sclerosis (SSc) compared with healthy controls. METHODS: Twenty-nine patients with SSc and 29 control subjects were recruited. ...
Skrzypiec-Spring Monika - - 2007
The isolated perfused mammalian heart preparation was established in 1897 by Oscar Langendorff. The method was developed on the basis of the isolated perfused frog heart established by Elias Cyon at the Carl Ludwig Institute of Physiology in Leipzig, Germany in 1866. Observations made using both methods at the end ...
Cabrales Pedro - - 2006
The hamster window chamber model was used to study systemic and microvascular hemodynamic responses to extreme hemodilution with low- and high-viscosity plasma expanders (LVPE and HVPE, respectively) to determine whether plasma viscosity is a factor in homeostasis during extreme anemic conditions. Moderated hemodilution was induced by two isovolemic steps performed ...
Bitsch Rudi Georg - - 2006
OBJECTIVES: A standardized perfused ex vivo bovine liver model was used to evaluate the effect of organ perfusion on coagulation size and energy deposition during radiofrequency ablation (RFA) procedures. MATERIALS AND METHODS: Bovine livers were perfused in a tank after rinsing the prepared liver vessels with anticoagulants. Tyrode's solution, oxygenated ...
O'Neill Anne C - - 2006
BACKGROUND: Isolated perfusion models can yield important data regarding metabolism of the skin. An effective model must remain stable during perfusion but respond appropriately to metabolic and vascular stimuli. We describe the design and characterization of a tubed superficial epigastric isolated perfusion flap. MATERIALS AND METHODS: Tubed superficial epigastric flaps ...
Babbs Charles F - - 2006
Periodic z-axis acceleration (pGz)-CPR involves an oscillating motion of a whole patient in the head-to-foot dimension on a mechanized table. The method is able to sustain blood flow and long-term survival during and after prolonged cardiac arrest in anesthetized pigs. However, the exact mechanism by which circulation of blood is ...
Bond H - - 2006
Here we present methodology and validation (including measurement of unidirectional maternofetal clearance (Kmf) of (45)Ca and (14)C-mannitol) for in situ perfusion of the mouse placenta. On day 18 of gestation (term=19 days) mice were anaesthetised and the uterus delivered into a saline bath (40 degrees C). A fetus was selected, ...
Stirrat Alison - - 2006
Ascorbate blocks agonist-induced, endothelium-derived hyperpolarizing factor (EDHF)-mediated vasodilatation in the bovine perfused ciliary artery and this is associated with a rise in perfusion pressure. We now report the origins of this ascorbate-induced rise in perfusion pressure. In segments of ciliary artery perfused at 2.5 ml/min, the addition of ascorbate (10-150 ...
Nygren Andreas - - 2006
OBJECTIVES: To evaluate the potential differential effects of norepinephrine, an alpha1-, beta1-, and beta2-receptor agonist, to the alpha1-agonist phenylephrine on jejunal mucosal perfusion, gastric-arterial PCO2 gradient, and the global splanchnic oxygen demand-supply relationship after cardiac surgery. DESIGN: A randomized, prospective, interventional crossover study. SETTING: A university cardiothoracic intensive care unit. ...
Staudt Y - - 2006
BACKGROUND: Cardiac autoantibodies may play a pathophysiological role in cardiac dysfunction of patients suffering from dilated cardiomyopathy (DCM). Immunoadsorption (IA), which removes antibodies from patients' plasma, may consequently improve cardiac function in DCM. The functional effects of DCM antibodies are only partly understood. MATERIALS AND METHODS: DCM patients (n = ...
Ishiyama N - - 2006
The influence of coronary perfusion pressure on neonatal heart function has not been evaluated. We compared the coronary perfusion pressure-cardiac function relationship between neonatal and adult hearts. Neonatal and adult rabbit hearts were examined. The coronary perfusion pressure was changed in increments of 10 mmHg. Coronary blood flow and left ...
Krouzecky A - - 2006
Limited information is available about selection of the threshold for arterial blood pressure in critically ill patients, particularly in sepsis when normal organ blood flow autoregulation may be altered. The present experimental study investigated whether increasing perfusion pressure using norepinephrine in normotensive hyperdynamic porcine bacteremia affects intestinal macro- and microcirculation. ...
Phillips Oludotun A - - 2006
The effects of methanolic and aqueous extracts of Tribulus terrestris on rat blood pressure (BP) and the perfused mesenteric vascular bed were investigated. The extracts dose-dependently reduced BP in spontaneously hypertensive rats (SHRs) with the aqueous fraction being more potent than the methanolic fraction at all doses tested. In vitro, ...
Stocchetti Nino - - 2005
BACKGROUND: The authors propose that for a moderate reduction of perfusion during progressive irreversible ischemia, oxygen extraction increases to maintain aerobic metabolism, and arteriojugular oxygen difference (AJDo2) increases. Because of reduced carbon dioxide washout, venoarterial difference in carbon dioxide tension (DPco2) increases, with no change in the DPco2/AJDo2 ratio. With ...
Kjaer Andreas - - 2005
Myocardial perfusion (MP) may differ in physiologic and pathologic left ventricular hypertrophy (LVH). We compared MP in LVH in elite athletes and patients with hypertension with healthy, age-matched subjects. We included 12 rowers with LVH, 19 patients with hypertension with LVH, and 2 age-matched groups of healthy subjects (n = ...
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