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Results 551 - 600 of 1624
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Fonteles C S - - 2001
Adult male guinea pigs from both sexes were anaesthetized with pentobarbital (40mg/Kg). After tracheotomy the lungs were perfused with Krebs-Henseleit solution at 37 degrees C in a non recirculated system composed of a perfusion pump, a transducer to measure pressure and another one to measure bronchial resistance. In all groups ...
Khatib S Y - - 2001
Allopurinol, a competitive inhibitor of xanthine oxidase, was found to have a protective effect on ischemic myocardium. Its mechanism of action is still controversial. We used Langendorff isolated rat heart preparation to test the hypothesis that allopurinol could maintain a level of the adenine nucleotide pool (ATP, ADP, and AMP) ...
Armour J - - 2001
Septic patients have low plasma ascorbate concentrations and compromised microvascular perfusion. The purpose of the present experiments was to determine whether ascorbate improves capillary function in volume-resuscitated sepsis. Cecal ligation and perforation (CLP) was performed on male Sprague-Dawley rats. The concentration of ascorbate in plasma and urine, mean arterial blood ...
Orihashi K - - 2001
BACKGROUND: We evaluated clinical relevance of orbital ultrasound (OUS) monitoring to neurological events in aortic surgery associated with selective cerebral perfusion (SCP). METHODS: In 24 consecutive cases, blood flow was monitored at central retinal artery (CRA) and retrobulbar vessels. The threshold perfusion pressure for detecting CRA flow in the color ...
Davidson G W - - 2001
Administration of exogenous Ach to isolated in situ saline-perfused hearts of Anguilla australis via the perfusate, resulted in reduction in cardiac frequency (F). This reduction in F became significant at Ach concentrations of 10(-11) M or greater. A weak inotropic effect of Ach at the lowest concentration tested (10(-13) M) ...
Tominaga R - - 2001
The changes in systemic circulation during hyperthermic isolated lower limb perfusion with carboplatin and interferon-beta were investigated in 19 patients with malignant melanoma. The cardiac output (CO) increased significantly (p < 0.01) from 3.81 +/- 0.22 L/min before the procedure to 5.30 +/- 0.49 L/min 1 h after hyperthermic perfusion. ...
Yang T - - 2000
The effect of cerebral and spinal cord protection by a modified perfusion technique during the elephant trunk procedure was assessed. Between 1997 and 1998, six patients underwent selective cerebral perfusion (SCP) and lower half of the body perfusion (LBP), in which the right subclavian and left femoral arteries were separately ...
Gustafson L A - - 2000
The purpose of this study was to develop a technique for determination of the dynamic regulation of oxidative myocardial metabolism in the mouse. The response time of myocardial oxygen consumption (MVO(2)) to a step in heart rate was determined in Langendorff-perfused mouse hearts. We examined the effect of glucose-only perfusate ...
Hoeldtke N J - - 2000
OBJECTIVE: This study was undertaken to determine whether adrenomedullin, a hypotensive peptide, decreases vasomotor tone in fetoplacental vasculature that has been constricted with the thromboxane sympathomimetic U46619. STUDY DESIGN: The fetoplacental vascular beds of 20 perfused human placental cotyledons were vasoconstricted with a continuous infusion of U46619 (10(-8) mol/L). The ...
Zhang X Y - - 2000
Convective transport of therapeutic agents in solid tumors can be improved through intratumoral infusion. To optimize the convection, we investigated the dependence of the hydraulic conductivity on tissue deformation induced by interstitial fluid pressure gradient during the infusion. Two experimental systems were used in the investigation: 1) one-dimensional perfusion through ...
Wagner R K - - 2000
OBJECTIVE: To determine if lipopolysaccharide (LPS) alters production of interleukin-6 (IL-6) or vascular tone in perfused placental cotyledons. METHODS: Control and study cotyledons from nine placentas were perfused for 3 h. Study cotyledons received LPS in concentrations of 0.01 mcg/ml (n = 3), 0.1 mcg/ml (n = 3), or 1.0 ...
Jahr J S - - 2000
The effects of heparinase I and protamine sulfate on the mean arterial pressure and hindlimb perfusion pressure in the male rat were studied. With institutional approval, 21 male Sprague-Dawley rats were anesthetized, and the carotid artery and abdominal aorta were cannulated by cutdown. To isolate the hindlimb, a semi-closed peristaltic ...
Nolte D - - 2000
BACKGROUND: Perfluorocarbon-based oxygen carriers have been proposed as an adjunct to autologous blood conservation techniques during elective surgery. To date, the effects of perfluorocarbon emulsions at the microcirculatory level have not been studied extensively. In this study the effects of perflubron emulsion on the microcirculation after acute normovolemic hemodilution (ANH) ...
Herrera B - - 2000
The main goal of this work was to study the influence of perfusion pressure and flow waveform during kidney perfusion, and the relationship between renal vascular resistance (RVR) and lactate dehydrogenase (LDH) concentration in the perfusate. Simultaneous constant pressure kidney perfusions were performed with either pulsatile or continuous flow at ...
Tanabe N - - 2000
Perfusion of the pulmonary acinus has been shown to be generally homogeneous, but there is a significant component that is heterogeneous. To investigate the contribution of the alveolar septal capillary network to acinar perfusion heterogeneity, the passage of fluorescent dye boluses through the subpleural microcirculation of isolated dog lung lobes ...
Yu P K - - 2000
Endothelial cell function is often evaluated by the assessment ofendothelium-dependent relaxation to acetylcholine. The purpose of this study was to characterize the acetylcholine-induced vasodilator responses in the intact ocular vasculature tree in isolated perfused rat eyes. At a fixed perfusion flow rate (5 microl/min), the resultant perfusion pressure reflected the ...
Pierce B T - - 2000
OBJECTIVE: Our purpose was to determine whether exposure of the isolated, perfused human placental cotyledon to different fetal circuit perfusion rates, and to concomitant pressure differences, alters placental production of interleukin 6 and tumor necrosis factor alpha. STUDY DESIGN: The maternal and fetal circulations of 2 cotyledons from 5 placentas ...
Craig A G - - 2000
Manometric assembly diameter is a major limitation on the number of perfused manometric recording points for recordings from the sphincter of Oddi (SO). We evaluated novel polyimide manometric assemblies whereby four recording channels were incorporated in an overall assembly diameter of 0.8 mm. Over the very low range of perfusion ...
Ujiie H - - 2000
Two cases with huge arteriovenous malformations (AVMs) who developed haemorrhagic complications after surgery are described. The cause of the postoperative haemorrhage was considered to be the normal perfusion pressure breakthrough phenomenon and/or occlusive hyperaemia. These two haemodynamic insults possibly occur simultaneously and induce life-threatening haemorrhage. It was concluded that a ...
Mruck S - - 2000
The aim of this study was to assess whether an in vitro preparation of force-generating human atrial trabeculae driven by external electrical stimulation is a suitable model for determining myocardial uptake of cardiotropic radiopharmaceuticals. METHODS: Human atrial trabeculae were excised from specimens removed during cardiac surgery for insertion of heart-lung ...
Serna D L - - 2000
Efforts to extend myocardial preservation for transplantation by crystalloid perfusion have been limited by edema and compromised function. We hypothesized that hypothermic perfusion preservation with a polyethylene glycol (PEG) conjugated hemoglobin solution may extend preservation times. The purpose of this study was to compare cardiac function after continuous perfusion by ...
Harada Y - - 2000
We investigated the roles of endothelium-derived vasodilative factors in rat hindquarter perfusion using a system for the direct measurement of nitric oxide (NO). Acetylcholine (ACh) induced the dose-dependent release of NO with a concomitant decrease in perfusion pressure. Under the influence of N(G)-monomethyl-l-arginine (l-NMMA), NO release in response to ACh ...
Fruhwald S - - 2000
OBJECTIVE: Catecholamines are frequently used in critically ill patients to restore stable hemodynamics and to improve organ perfusion. One effect of short-term or long-term administration of catecholamines may be inhibition of propulsive motility in the intestine. We therefore analyzed the effect of dopexamine, dobutamine, and dopamine on ileal peristalsis and ...
Margreiter J - - 2000
Neopterin is known in humans as a sensitive marker for diseases associated with increased activity of the cellular immune system. Recent studies report neopterin also to exhibit distinct effects: neopterin induces inducible nitric oxide synthase expression in rat vascular smooth muscle cells and activates translocation of nuclear factor- kappa B. ...
Szabó G - - 2000
BACKGROUND: Although hemodynamic instability and cardiac dysfunction after brain death are reported in the potential organ donor, the underlying mechanisms, for example, neurohumoral changes, myocardial injury, and altered loading conditions, have not been differentiated in clinical and experimental settings. In the present study, we performed a load-independent analysis of cardiac ...
Tanhehco E J - - 2000
Both free radicals and complement activation can injure tissue. Our study determined whether free radicals alter complement production by the myocardium. Isolated hearts from New Zealand White rabbits were perfused on a Langendorff apparatus and exposed to xanthine (X; 100 microM) plus xanthine oxidase (XO; 8 mU/ml) (X/XO). The free ...
Linakis J G - - 2000
To determine if lithium exerts direct cardiac toxicity, using an isolated, perfused rat heart model, paced and unpaced beating rat hearts were perfused with Krebs-Henseleit bicarbonate solution and left ventricular pressures were measured via a balloon-tipped catheter positioned in the left ventricle via the mitral valve. Following a stabilization period, ...
Keevil V L - - 2000
Changes in cardiac gap junction expression, such as those following myocardial infarction and produced in connexin knockout mice, are associated with a predisposition to arrhythmias. The present experiments investigated the effects of heptanol, a reversible gap junction inhibitor, on isolated Langendorff-perfused rabbit hearts. The introduction and withdrawal of heptanol inhibited ...
Richter O - - 2000
Experimental perfusion of various organs has primarily been used in transplantation medicine to study the physiology, pathophysiology and metabolism of tissues and cells. The purpose of this study was to establish an experimental model for the extracorporeal perfusion of the human uterus with recirculation of a modified, oxygenated Krebs-Henselait solution, ...
Gerbino A J - - 2000
Endotoxin increases ventilation-to-perfusion ratio (VA/Q) heterogeneity in the lung, but the precise changes in alveolar ventilation (VA) and perfusion that lead to VA/Q heterogeneity are unknown. The purpose of this study was to determine how endotoxin affects the distributions of ventilation and perfusion and the impact of these changes on ...
Suchkova V N - - 2000
BACKGROUND: We have shown previously that 40-kHz ultrasound (US) at low intensity accelerates fibrinolysis in vitro with little heating and good tissue penetration. These studies have now been extended to examine the effects of 40-kHz US on thrombolysis and tissue perfusion in a rabbit model. METHODS AND RESULTS: Treatment was ...
Garlick P B - - 2000
NMR spectroscopy is an invaluable technique in metabolic investigations of isolated, perfused hearts. Most studies employ global perfusion methods together with an NMR coil that surrounds the heart and thus detects signals from its entirety. The present report describes the construction and testing of a novel, two surface-coil probe, in ...
Sjögren L S - - 2000
We recently discovered that patients with essential hypertension have a markedly impaired capacity for stimulated release of tissue plasminogen activator (tPA) from vascular endothelium. This defect may reduce the chance of timely spontaneous thrombolysis in case of an atherothrombotic event. We now investigated whether increased intraluminal pressure as such may ...
Ehinger A M - - 2000
In vivo, tissue distribution of intra-mammarily administered antibiotics is mostly only assessed by sampling milk and blood. Therefore, the described study analysed whether measurement of tissue concentrations makes sense in vitro instead. Isolated bovine udders were perfused with gassed and warmed Tyrode solution. To four front and rear quarters each, ...
Nankervis C A - - 2000
Newborn intestine is uniquely prone to vasoconstriction in response to a wide variety of perturbations. To test the hypothesis that endothelin (ET)-1 is an important factor in this process, we determined the effects of exogenous ET-1 administration and blockade of endogenous ET-1 in vivo and in vitro in 3- and ...
Falck G - - 2000
The aim of the present study was to investigate the role of the Na+/K+/2Cl- co-transporter and the Na+/H+ exchanger on contractile function and electrolyte regulation during hyperosmotic perfusion of the heart. Langendorff perfused rat hearts were subjected to hyperosmolal perfusion in 10-min intervals. Perfusates were made hyperosmotic by adding mannitol ...
Richter S - - 2000
BACKGROUND: Current organ shortage has led to a reconsideration of non-heart-beating cadaveric donation. METHODS: We assessed the effectivity of dual, i.e., arterial and portal-venous versus exclusive, arterial gravity perfusion for procurement of rat livers after 30 min and 60 min of cardiac arrest, analyzing the rate and homogeneity of microvascular ...
Rossoni G - - 2000
In a previous paper we gave evidence that chronic oral defibrotide antagonizes the noxious effect of developing atherosclerosis in the cardiovascular system. In the present paper we give evidence that defibrotide is still capable of exerting beneficial effects on cardiovascular function once atherosclerosis is established. In fact, there was statistically ...
Semplicini A - - 2000
Focal cerebral hypoperfusion is a common finding in uncomplicated hypertensives even in the absence of large vessel atherosclerosis, and neuropsychological deficits correlate with cerebral hypoperfusion in hypertensive patients with cerebral microangiopathy. We investigated the effects on cerebral perfusion of the dihydropiridine calcium antagonist lacidipine and of hydrochlorothiazide (HCTZ) in asymptomatic ...
Arildsson M - - 2000
Local topical analgesia changes basal skin perfusion and its regulation. In particular, the response induced by local heating, which in nontreated skin comprises a rapidly increased perfusion followed by a normalization within 30 s, is altered to a delayed and persistent perfusion increase. The response dependency to the analgesia cream ...
Stangl M J - - 2000
BACKGROUND: In the present study, a technique for computer-assisted, normothermic, oxygenated, ex vivo, recirculating small bowel perfusion was established as a tool to investigate organ pretreatment protocols and ischemia/reperfusion phenomena. A prerequisite for the desired setup was an organ chamber for ex vivo perfusion and the use of syngeneic whole ...
Chamot S R - - 2000
The relationship between blood flow and ocular perfusion pressure in the iris vascular bed of the human eye has not been established yet. Consequently, it is not known whether the iris circulation has some autoregulatory capacity. The aim of the present study was to investigate this relationship in the particular ...
Zhang J - - 2000
Hyperthermochemotherapeutic perfusion model through isolated pelvic vessels was developed to evaluate the leakage of hyperthermia and drugs (such as adriamycin) from the isolated pelvic circulation to systemic circulation and its associated side/toxic effects. The isolated pelvic circulation was perfused through a femoral artery catheter with hyperthermic (48 degrees C to ...
Andlauer W - - 2000
Resveratrol, which is present in grapes, wine and peanuts, is believed to possess chemoprotective properties such as anticarcinogenic effects and to provide protection against cardiovascular diseases. Little is known, however, about its intestinal absorption. We investigated the absorption and metabolism of resveratrol by using an isolated preparation of luminally and ...
Müller-Berger S - - 1999
In the present experiments on microdissected tubules of rabbit kidney we present a refined stop-flow method for determining the rate of HCO3- absorption (J(HCO3)) or H+ secretion (JH) that can be applied to isolated microperfused tubules. Using the pH-sensitive indicator dye BCECF (2',7'-bis [2-carboxyethyl]-5[6]-carboxyfluorescein) the luminal perfusate pH is continuously ...
Lachenbruch C A - - 1999
A network thermodynamic model has been devised to describe the coupled movement of water and a permeable additive within a kidney during perfusion under the combined action of diffusive, hydrodynamic, and mechanical processes. The model has been validated by simulating perfusions with Me2SO, glycerol, and sucrose and comparing predicted weight ...
Ide H - - 1999
The effects of airway (AH) and vascular hypoxia (VH) on the production of nitric oxide (NO; VNO) were tested in isolated buffer-perfused (BFL) and blood-perfused rabbit lungs (BLL). To produce AH and/or VH, the lung was ventilated with 1% O(2) gas, and/or the perfusate was deoxygenated by a membrane oxygenator ...
Guppy L J - - 1999
We previously reported findings consistent with a marked upregulation in functional L-type voltage-operated calcium channels (L-VOCCs) in hearts obtained from rats exposed over the long term to ethanol. These experiments were undertaken to establish whether detrimental effects on cardiac function were associated with excess calcium entry into the myocardium in ...
Ichihara A - - 1999
This study was designed to examine the contribution of cyclooxygenase-2 (COX-2) in the afferent arteriolar autoregulatory responses to increases in perfusion pressure and its relationship with neuronal nitric oxide synthase (nNOS). In rat kidneys, afferent arteriolar diameter responses to increases in perfusion pressure were assessed in vitro with the blood-perfused ...
Ubbink D T - - 1999
BACKGROUND: Various vasoconstriction mechanisms after a change in posture are involved in controlling skin blood flow and capillary transmural pressure to maintain adequate transcapillary exchange. The role of venous orthostatic pressure in the regulation of capillary nutritive perfusion, however, is less clear. DESIGN: We investigated capillary perfusion in 30 healthy ...
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