Search Results
Results 401 - 450 of 1561
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Hillis A E - - 2004
We carried out baseline and short-term follow-up MRI, including perfusion-weighted imaging (PWI) and tests of neurologic and cognitive function on 15 consecutive patients with large-vessel ischemic stroke who showed a persistent large perfusion-diffusion mismatch at enrollment up to seven days after the onset of symptoms. Of these, ten underwent induced ...
Månsson Sven - - 2003
The ability to quantify pulmonary diffusing capacity and perfusion using dynamic hyperpolarized (129)Xe NMR spectroscopy is demonstrated. A model of alveolar gas exchange was developed, which, in conjunction with (129)Xe NMR, enables quantification of average alveolar wall thickness, pulmonary perfusion, capillary diffusion length, and mean transit time. The technique was ...
Nandate Koichiroh - - 2003
We studied the effects of pneumoperitoneum on gastric submucosal perfusion metabolism during elective laparoscopic cholecystectomy (LASC) by measuring the PCO(2) gap, defined as the difference between intramucosal PCO(2) and arterial PCO(2), using gas tonometry in 20 patients. Furthermore, we examined whether thoracic epidural anesthesia (TEA) affects gastric submucosal perfusion metabolism ...
Champion Hunter C - - 2003
BACKGROUND: Viral gene transfer to the whole heart in vivo has been achieved in several mammalian species but remained difficult to accomplish in murine hearts. We postulated that a key impediment derives from the use of proximal aortic occlusion during virus injection, because this eliminates coronary perfusion gradients in mice ...
Sutherland Fiona J - - 2003
1. Owing to the considerable potential for manipulating the murine genome and, as a consequence, the increasing availability of genetically modified models of cardiovascular diseases, the mouse is fast becoming a cornerstone of animal research. However, progress in the use of various murine preparations is hampered by the lack of ...
Tannergren Christer - - 2003
OBJECTIVE: Our objective was to investigate the main in vivo transport mechanisms of fexofenadine involved in the intestinal absorption and bioavailability of the drug in humans. METHODS: A jejunal single-pass perfusion study was performed in 10 healthy volunteers. Each experiment lasted for 200 minutes and was divided into 2 periods ...
Heijnen Bob H M - - 2003
OBJECTIVE: We attempted to assess liver ischemia/reperfusion injury under a mild decrease in core liver temperature of 10 degrees C by in situ hypothermic perfusion during ischemia. METHODS: Liver ischemia was induced in pigs by total hepatic vascular exclusion with concomitant in situ perfusion with hypothermic (4 degrees C) Ringer-glucose ...
Ba Zheng F - - 2004
Although gender differences exist in cardiovascular endothelial function, it remains unclear whether such differences are also seen in small intestinal endothelial function. To determine this, untreated male, age-matched proestrus female, castrated male, and 17beta-estradiol (E2)-treated noncastrated male rats were studied. Dose response curves to ACh and nitroglycerin (NTG) were determined ...
Dittrich R - - 2003
The objective of this study was to establish an experimental model for extracorporeal perfusion of swine uterus. In order to validate this model, we examined some biochemical parameters and determined the effect of oxytocic drugs (Oxytoxin, Prostaglandin E (2)) on extracorporeal perfused swine uteri. Thirty swine uteri were perfused with ...
Ståhl N - - 2003
We describe a penumbra zone with increased biochemical vulnerability in cerebral cortex underlying an evacuated acute subdural haematoma. Two microdialysis catheters were placed in this zone and one catheter was placed in the opposite, less injured hemisphere. The microdialysis perfusates were analysed bedside for glucose, pyruvate, lactate, glutamate, and glycerol. ...
Lehtipalo Stefan - - 2003
OBJECTIVE: To evaluate the net effects of the concomitant use of positive end-expiratory pressure (PEEP) and dopexamine on intestinal tissue perfusion and oxygenation during predefined artificial reductions in intestinal perfusion pressure (IPP). DESIGN: Prospective, self-controlled, experimental study. SETTING: University hospital research laboratory. SUBJECTS: Seven female pigs. MEASUREMENTS: In barbiturate-anesthetized pigs, ...
Kroppenstedt Stefan-Nikolaus - - 2003
OBJECTIVES: Reduction of cerebral perfusion during the early phase after traumatic brain injury is followed by a later phase of normal to increased perfusion. Thus, pharmacologically elevating mean arterial blood pressure with the aim of improving cerebral perfusion may exert different time-dependent effects on cortical perfusion, microcirculation, tissue oxygenation and ...
Nygren Andreas - - 2003
OBJECTIVES: To evaluate the effect of norepinephrine alone and norepinephrine combined with dopamine on jejunal mucosal perfusion, gastric-arterial pCO(2) gradient, and global splanchnic oxygen demand-supply relationship after cardiac surgery. DESIGN: A prospective interventional study. SETTING: A university cardiothoracic intensive care unit. PATIENTS: Eighteen patients were studied during propofol sedation and ...
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 ...
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