Search Results
Results 351 - 400 of 1624
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Garbade Jens - - 2008
Continuous blood perfusion of donor hearts for transplantation has been the focus of an increasing amount of research, but the optimal preparation and perfusion techniques have not been clearly defined. Therefore, we investigated the effectiveness of different preservation strategies using continuous, normothermic heart perfusion after donor heart harvesting. Hearts of ...
Trivedi Monica M Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, - - 2009
Head injury remains a major cause of preventable death and serious morbidity in young adults. Based on the available evidence, it appears that a cerebral perfusion pressure of 50 to 70 mm Hg is generally adequate to ensure cerebral oxygen delivery and prevent ischemia. However, evidence suggests that perfusion requirements ...
Khoury Wisam - - 2008
BACKGROUND: Variable mechanisms were suggested to mediate the changes in renal hemodynamics during pneumoperitoneum. To assess whether it can be pressure dependent only, we conduct a study in an isolated, pressurized, and perfused organ model. METHODS: Seventy Wistar rat kidneys were perfused with oxygenated, 3% albumin-contained Krebs-Henseleit solution. Experiments took ...
Ogoh Shigehiko - - 2008
On the basis of measurement techniques that require steady-state hemodynamic conditions when the measurement of cerebral blood flow (CBF) is being obtained, cerebral autoregulation (CA) maintains CBF stable over a wide range of cerebral perfusion pressures. When an acute (or dynamic) change in cerebral perfusion pressure (seconds) is imposed, CBF ...
Hoffmann Michael J - - 2008
The repeatability and resolution of the clinical gold standard of vascular assessment, the ankle-brachial index (ABI), was compared to that of a new device that dynamically assesses tissue perfusion during external loading utilizing laser Doppler flowmetry. Eight subjects of varying levels of vascular impairment were tested in successive weeks using ...
Overholser Brian R - - 2008
STUDY OBJECTIVE: To determine the catecholaminergic effects on the duration of ventricular repolarization during inhibition of the rapid component of the delayed rectifier potassium current (I(Kr)). DESIGN: Isolated perfused heart model. SETTING: University research center. ANIMALS: Eighteen male Dunkin-Hartley guinea pigs. INTERVENTION: Hearts were excised and perfused in a retrograde ...
Hsiu Hsin - - 2008
We used laser Doppler flowmetry (LDF) and spectrum analysis to investigate the microcirculatory responses to pressure stimulation (PS) of the skin surface. A control group without PS applied, and four groups with different PS (20, 60, 100 and 160 mmHg in groups PS(20), PS(60), PS(100) and PS(160), respectively) were formed ...
Cabrales Pedro - - 2008
O2-carrying fluids based on hemoglobin (Hb) are in various stages of clinical trials to determine their suitability as O2-carrying plasma expanders. Polymerized Hb solutions are characterized by their vasoactivity, low O2 affinity, oncotic effect, prolonged shelf life, and stability. Physiological responses to facilitated O2 transport after exchange transfusion with polymerized ...
Singh Raja B - - 2008
Isolated hearts subjected to ischemia-reperfusion (I/R) exhibit depressed cardiac performance and alterations in subcellular function. Since hearts perfused at constant flow (CF) and constant pressure (CP) show differences in their contractile response to I/R, this study was undertaken to examine mechanisms responsible for these I/R-induced alterations in CF-perfused and CP-perfused ...
Banegas Inmaculada - - 2008
Control of blood pressure is partially accomplished by several proteolytic enzymes included in the renin-angiotensin system. These enzymes produce several peptides that form the active components of the system. Study of these enzymes is essential for a deep understanding of blood pressure control and could offer the possibility of controlling ...
Gabriel Edmo Atique - - 2008
Thirty-two pigs were randomized into group I (aortic cross clamping, antegrade cardioplegia, moderate hypothermia) and group II (normothermia, beating empty heart). Groups were subdivided into subgroups A, B and C, receiving no lung perfusion, perfusion with arterial blood and perfusion with venous blood. Swan-Ganz catheter was used to take mean ...
Ren YiLin - - 2008
Tubuloglomerular feedback (TGF) is the mechanism by which the macula densa (MD) senses increases in luminal NaCl concentration and sends a signal to constrict the afferent arteriole (Af-Art). The kidney expresses constitutively heme oxygenase-2 (HO-2) and low levels of HO-1. HOs release carbon monoxide (CO), biliverdin, and free iron. We ...
Cheng Y - - 2008
The contribution of triacylglycerol to energy provision in the hypertrophied heart, mediated through lipoprotein lipase (LPL) is largely unknown and the contribution of very-low-density lipoprotein (VLDL) receptor to control of LPL presentation at the endothelium is unclear. For isolated perfused rat hearts, cold acclimation (CA) induced volume-overload hypertrophy, with decreased ...
Stowe David F DF Anesthesiology Research Laboratory, Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA. - - 2008
Donor human hearts cannot be preserved for >5 hours between explantation and recipient implantation. A better approach is needed to preserve transplantable hearts for longer periods, ideally at ambient conditions for transport. We tested whether Lifor solution could satisfactorily preserve guinea pig isolated hearts perfused at low flow with no ...
Theodorou Dimitrios - - 2008
AIMS: To evaluate the impact of the perioperative administration of norepinephrine on the perfusion of the esophageal graft. METHODS: This is an experimental study. Six swine underwent transhiatal esophagectomy; the stomach was used to replace the resected esophagus. We provoked hemorrhagic shock to the animals and then we administered noradrenaline ...
Cabrales Pedro P La Jolla Bioengineering Institute, Department of Bioengineering, University of California, San Diego, La Jolla, California 92037, USA. - - 2008
Hemoglobin (Hb) solutions are potential alternatives to blood transfusion when native oxygen (O(2))-carrying capacity is lacking. Polymerized bovine Hb (PBH) solutions are characterized by its vasoactivity, low O(2) affinity, oncotic effect, prolonged shelf life, and stability. Responses to facilitated O(2) transport, after exchange transfusion with PBH, were studied in the ...
He, Yong
Introduction: Vascular cells communicate through gap junctions, which are formed by connexin (Cx) proteins. Cx43 is expressed in both endothelial and smooth muscle cells. Studies have demonstrated alterations in gap junctions with atherosclerosis and hypertension, diseases that involve changes in mechanical forces. However, regulation of arterial gap junctions by mechanical ...
Conhaim Robert L - - 2008
Acute hemorrhage is often followed by devastating lung injury. However, why blood loss should lead to lung injury is not known. One possibility is that hemorrhage rapidly disturbs the distribution of microvascular perfusion at the alveolar level, which may be a triggering event for subsequent injury. We showed previously that ...
Ergün Eser Lay - - 2008
PURPOSE: This study aims to investigate whether induction with metamizol, an analgesic-antipyretic drug having spasmolitic activity, could be used to increase the detectability of ischemic/jeopardized myocardium during MPS (myocardial perfusion scintigraphy). MATERIALS AND METHODS: Metamizol-enhanced rest MPS (45 min after administration of 1 g metamizol orally, 740 MBq (99m)Tc sestamibi ...
Patel Vanlata H - - 2008
4,5-Diaminofluorescein (DAF-2) has been used to measure nitric oxide (NO) activity from a variety of preparations. The aim of this study was to develop a method to assess changes in NO fluorescence using DAF-2 in isolated rabbit hearts (2.0-2.5 kg, n = 8). Hearts were perfused in constant flow Langendorff ...
Doughty Michael J - - 2008
PURPOSE: To quantitatively assess the effects of pH on the corneal stroma under an applied hydrostatic pressure. METHODS: Sclera-stroma preparations from adult sheep eyes were perfused with isotonic mixed salts solutions at 37 degrees C for 9 hr under an applied hydrostatic pressure and then fixed for electron microscopy. RESULTS: ...
Ramond Amandine - - 2008
The use of chemotherapeutic agents, such as anthracycline or trastuzumab, in oncology is limited by their cardiac toxicity. Recent experimental studies suggest that recombinant human erythropoietin (rhEPO) can be considered as a protective agent because its administration protects against cardiac ischemic injury, improving functional recovery, and reducing cell death. The ...
Müller Michael - - 2008
ABSTRACT: BACKGROUND: The severity of associated soft tissue trauma in complex injuries of the extremities guides fracture treatment and decisively determines patient's prognosis. Trauma-induced microvascular dysfunction and increased tissue pressure is known to trigger secondary soft tissue damage and seems to adversely affect skeletal muscle function. METHODS: 20 patients with ...
Bytautiene Egle - - 2008
The objective of this study is to investigate the effect of a mast cell degranulating agent, compound 48/80, on vascular resistance in the perfused human placenta and on the tone of isolated human chorionic vessels. Human placenta was obtained from term nonlaboring women undergoing cesarean delivery. Placental vascular bed perfusion ...
Gernhardt Christian Ralf - - 2008
This study evaluated the influence of defined pressure application before light-curing on the tensile bond strength (TBS) of two adhesive systems to wet and perfused dentin. Bonding sites were analyzed by scanning electron microscopy (SEM) to assess morphological changes. Dentin discs from 120 human third molars were prepared in such ...
Trejo Humberto E - - 2007
BACKGROUND AND OBJECTIVE: Mechanical obstruction has been considered the prime determinant of haemodynamic changes after pulmonary embolism (PE); however, the function of vasoconstrictive and inflammatory mediators in the physiopathology of this disease is unclear. The aim of this investigation was to study the effect of an anti-inflammatory and a vasodilator ...
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 ...
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