Search Results
Results 401 - 450 of 1090
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Loeschke K - - 1994
To explore the quantitative significance of passive water flow through tight junctions of leaky epithelia, transepithelial water flow rates were measured in Necturus gallbladder mounted in chambers. Osmotic flows generated by raffinose gradients were asymmetrical with the greater flow in the mucosal-to-serosal direction. In tissue fixed in situ, intercellular spaces ...
Marroni N - - 1994
The effects of chronic normovolemic anemia on gastric microcirculation and gastric mucosal susceptibility to ethanol-induced gastric damage were investigated in anesthetized rats. Blood exchange by a plasma expander during four consecutive days rendered the animals anemic with a 34% decrease in the baseline hematocrit but without affecting blood volume. Chronic ...
Guslandi M - - 1994
Twelve patients with dyspepsia whose gastric abnormalities ranged from diffuse reddening of the mucosa to multiple erosions were treated for 4 weeks with oral sulglycotide, a sulphated glycopeptide with known gastroprotective and ulcer-healing properties. Before and after treatment, gastric mucosal blood flow was assessed by means of laser Doppler flowmetry. ...
Zhang X Y - - 1994
In anesthetized rats we tested the hypothesis that cigarette smoke potentiates acid-induced duodenal mucosal injury by inducing mesenteric vasoconstriction. Rats inhaled room air or 6 or 12 ml/min cigarette smoke. Study 1: 0.1 N HCl-induced duodenal mucosal injury and H+ loss were assessed by histologic evaluation and titration, respectively. Study ...
Tanaka T - - 1994
The effect of 3-ethyl-1-(6-hydroxy-6-methylheptyl)-7-propylxanthine (A90 6119) on 40% ethanol-induced gastric lesions and gastric mucosal blood flow was investigated in rats. Gastric mucosal blood flow was measured by the hydrogen gas clearance technique and the test compounds and vehicle were administered intraduodenally. A90 6119 dose-dependently increased gastric mucosal blood flow and ...
Zacchi P - - 1994
The impact of stress on gastroesophageal reflux and antireflux mechanisms remains largely unexplored. To a major extent, reflux depends on a balance between gastroesophageal junction resistance to flow and gastric tone. We hypothesized that these two forces could be differently affected by stress, and to test the hypothesis we quantified ...
Konturek S J - - 1994
Gastric mucosa adapts to ulcerogenic action of aspirin but the mechanism of this phenomenon is unknown. In this study, acute gastric lesions were produced by single or repeated oral administration of acidified aspirin in rats with intact or deactivated (by capsaicin) sensory nerves and with intact or suppressed synthase of ...
Wood J G - - 1994
We compared the effects of endothelin-1 and its precursor, big endothelin-1, on vascular resistance of a blood-perfused ex vivo stomach segment of chloralose-anesthetized dogs. In separate groups of dogs, endothelin-1 or big endothelin-1 was infused intra-arterially directly to the gastric segment. Endothelin-1 caused statistically significant dose-related increases in gastric vascular ...
Gaer J A - - 1994
Gastric mucosal tonometry was used to determine the adequacy of gastrointestinal perfusion in 10 patients undergoing elective myocardial revascularization. Patients were prospectively randomized to receive either pulsatile or nonpulsatile flow during cardiopulmonary bypass. All patients showed a reduction in gastric mucosal perfusion during bypass, manifested by a reduction in the ...
Grönbech J E - - 1994
BACKGROUND/AIMS: Sensory neurons in the stomach mucosa are closely apposed to mast cells and blood vessels. Mucosal hyperemia, after exposure to capsaicin, is mediated by calcitonin gene-related peptide (CGRP) from these neurons, which also contain substance P (SP). However, the role of this peptide in blood flow regulation remains unclear. ...
Fishbein V A - - 1994
An apparently novel entity, diffuse hemorrhagic gastroenteropathy (DHG), in a 70-year-old female who had an unremitting course of chronic gastrointestinal blood loss for 3 years requiring transfusion of more than 200 units of packed red blood cells over this period is reported here. Endoscopy showed diffusely hemorrhagic mucosa in the ...
Nakahara R - - 1994
Using the hydrogen gas clearance method, a plate-type probe was attached to the surface of the cuff of an endotracheal tube in order to measure the ischemic changes in the tracheal mucosa produced by peritracheal lymph node dissection. In eight human subjects with intrathoracic esophageal carcinoma, the tracheal mucosal blood ...
Sullivan T R TR - - 1994
Topical application of 5 mM sodium taurocholate (5 TC, pH 1.2) to canine gastric mucosa results in luminal hydrogen ion (H+) loss and surface epithelial cell (SEC) injury. However, gross mucosal injury does not occur because of a protective increase in gastric mucosal blood flow (GMBF). The mechanism of this ...
Aust R - - 1994
Experimental studies of human maxillary sinus gas exchange show that there is a balance between inflow of air through the maxillary ostium and local consumption as long as the functional size of the ostium is at least 5 mm2. Maxillary sinus mucosal blood flow is 30-40 ml/100 g tissue per ...
Larson M V - - 1994
BACKGROUND: Several in vivo techniques that assess mucosal perfusion by intraluminal probes have recently been developed and validated, including laser Doppler flowmetry, reflectance spectrophotometry, and tonometry. METHODS: With these techniques, a canine model where the entire vascular supply to the jejunoileum was isolated as the superior mesenteric artery and vein ...
Tarnasky P R - - 1994
The aim of this study was to evaluate the effects of octreotide, a long-acting somatostatin analogue, on canine gastric mucosal blood flow and hemodynamics. We hypothesized that octreotide might decrease gastric mucosal blood flow without causing adverse hemodynamic effects. Two groups of dogs were anesthetized (six normal dogs and six ...
Cho C H - - 1994
One of the ulcerogenic mechanisms by which ethanol induces mucosal lesions in the stomach is the depression of gastric mucosal blood flow (GMBF). The goal of this study was to determine whether lesion formation is the result of vascular ischemia alone or ischemia combined with congestion. The aims of this ...
Rybárová S - - 1994
The role of afferent sensory neurones in gastric mucosal protection is discussed. The principal effects of substance P and capsaicin on gastric motility and mucosal blood flow are taken in correlation with gastric mucosal injury. It seems likely that the protective effect of sensory neuropeptides is dependent on gastric mucosal ...
Konturek S J - - 1994
It has become apparent recently that acute gastric mucosal lesions caused by a single exposure of the gastric mucosa to nonsteroidal antiinflammatory drugs (NSAID) or other irritants decrease with repeated insults indicating the ability of the mucosa to adapt to these damaging agents. This review evaluates the short-term and long-term ...
Thürauf N - - 1993
Slow electrical responses after painful stimulation with carbon dioxide, which is known to specifically activate nociceptors, were recorded from the nasal respiratory epithelium in human volunteers. The negative component of these potentials (negative mucosal potential NMP) has been hypothesized to be a summated receptor potential. The aim of the present ...
Konturek S J - - 1993
Nonsteroidal anti-inflammatory agents (NSAIDs) such as aspirin (ASA) damage the gastric mucosa both in normal subjects and in arthritic patients. The aim of this study was to investigate the protective action of a new H2-receptor antagonist, ebrotidine, in the prevention of ASA-induced acute mucosal injury in the stomach of healthy ...
Nylander O - - 1993
The relationship between duodenal mucosal alkaline secretion, permeability, and blood flow was examined in anesthetized rats. Duodenum was perfused with saline, and rate of luminal alkalinization (LA), mucosal permeability (clearance of 51Cr-EDTA from blood to lumen), effluent volume, mean arterial blood pressure (MABP), and blood flow (laser-Doppler flowmetry) were determined. ...
Ma J J - - 1993
The time-course effects of portal hypertension on gastric secretory function, mucosal blood flow, vascular permeability, and ethanol-induced gastric mucosal damage were examined in anesthetized rats. Partial ligation of the portal vein effectively produced portal hypertension one to three days later but the raised pressure returned to normal on the sixth ...
Johnson D A - - 1993
The mechanism by which decongestants produce their action is activation of postjunctional alpha-adrenergic receptors found on precapillary and postcapillary blood vessels of the nasal mucosa. Activation of these receptors by either direct binding of the sympathomimetic agent to the binding site of the receptor, or by the enhanced release of ...
Frantz R - - 1993
Although the physiological effects of pressure on tissue have been demonstrated in the animal model, little is known about its effect in ill, elderly patients who are at risk for pressure ulcers. This study describes the pattern of dermal blood flow during a period of constant, low-level, compressive pressure in ...
Guslandi M - - 1993
Erosive duodenitis is a clinical entity whose pathogenesis is still obscure. Acid secretion is mostly normal, while the possible role of vascular factors has been suggested. We measured mucosal blood flow by means of laser Doppler velocimetry during endoscopy in the duodenal bulb of 10 subjects with erosive duodenitis, 10 ...
Hierlihy L E - - 1993
Vagal stimulation has been shown to result in the development of gastric mucosal erosions in the rat, although the mechanisms underlying the development of such erosions are not known. The effects of vagal stimulation on gastric acid secretion and mucosal blood flow were examined in urethane-anesthetized male Sprague-Dawley rats to ...
Gabryelewicz A - - 1993
The pathophysiological mechanisms of peptic ulcer and reflux oesophagitis are described. Special attention has been paid to the gastric mucosal defence factors, e.g. epidermal growth factor, mucosal blood flow and gastric mucus. The possible effects of neutrophils activation on nitric oxide generation and gastric mucosal capillary blood flow are discussed. ...
Konturek S J - - 1993
We investigated the influence of inhibition of nitric oxide (NO) synthase, using NG-nitro-L-arginine (L-NNA) or NG-mono-methyl-L-arginine (L-NMMA), and the effects of exogenous donor of NO, such as glyceryl trinitrate (GTN), on the healing of chronic gastric ulcers induced by acetic acid, on gastric blood flow around the ulcer and on ...
Nishizaki Y - - 1993
BACKGROUND: The mechanism by which topical isoproterenol protects the gastric mucosa from ethanol-induced injury is unclear; previous studies suggest that enhancement of mucosal blood flow may be contributory. Therefore, we investigated the role of isoproterenol pretreatment on rat gastric mucous gel layer thickness, mucosal blood flow, and surface cell intracellular ...
Livingston E H - - 1993
The stomach is prone to ulceration because of the hostile environment that exists within its lumen. The most important etiologic factor remains a topic of debate. We have considered the stomach as a system to lend insight into which pathophysiologic mechanisms might be most important. Systems are described by their ...
Holm L - - 1993
The influence of tactile stimulation of the gastric mucosa (mimics the mechanical influence of the food bolus) on the gastric mucosal blood flow and acid output was studied in rats anesthetized with Inactin. Blood flow was measured with laser-Doppler flowmetry (LDF) with the probe positioned above the gastric mucosa, and ...
Anan K - - 1993
Since ablation of afferent nerves prior to stress results in increased severity of acute gastric mucosal lesions, afferent nerves are thought to mediate protective mechanisms in the stomach. These mechanisms are known to include vasodilation of gastric mucosal vessels; vasodilation is thought to allow the gastric mucosa to respond to ...
Mercer D W - - 1993
Topical isoproterenol protects the gastric mucosa from the severe necrosis induced by 100 per cent ethanol. Its effect on gastric mucosal blood flow is unknown. The purpose of this study was to determine the effect of topical isoproterenol on gastric mucosal blood flow and on the less severe gastric mucosal ...
Sørbye H - - 1993
Dimethyl sulfoxide applied intragastrically for 10 min in rats caused extensive mucosal damage. In concentrations of 5%, 10%, or 100%, dimethyl sulfoxide caused superficial damage to 33%, 36%, and 97%, respectively, of the corpus mucosa, and 28%, 44%, and 96%, respectively, of the antral mucosa. Concentrated dimethyl sulfoxide also caused ...
Livingston E H - - 1993
It is not known how the signal to increase gastric mucosal blood flow is passed from the gastric parietal cell layer to the resistance vessels in the submucosa. We tested the hypothesis that mucosal hyperemia accompanying stimulated gastric acid secretion is mediated by capsaicin-sensitive sensory nerves. Rats were denervated by ...
Kaise M - - 1993
We studied the dopaminergic regulation of the gastric mucosal blood flow (GMBF) measured with an endoscopic laser Doppler flowmetry in 27 healthy volunteers. They were randomly assigned to receive an endoscopic gastric submucosal injection (0.5 ml) of physiological saline (control group, N = 10), 50 micrograms of dopamine (DA) hydrochloride ...
Noc M - - 1993
Measurement of gastric wall PCO2 has emerged as a promising monitor of perfusion deficits during low-flow states of circulatory shock. In the present study, gastric luminal PCO2 measured with the gastric tonometer was compared with the PCO2, measured directly in the wall of the stomach during hemorrhagic shock in two ...
Guttu K - - 1993
BACKGROUND: Gastric mucosal damage leads to luminal alkalinization, but its dependence on mucosal blood flow and acid secretory state of the mucosa is not known. This study examined release of bicarbonate to the gastric lumen and mucosal blood flow in cats after mucosal damage caused by 2 mol/L NaCl and ...
Livingston E H - - 1993
Cold water immersion restraint (CWIR) is associated with gastric hypercontractility and gastric corpus erosions in the rat. Because the gastric blood flow response to CWIR has not been well defined, we performed the following study. Rats were implanted with force transducers, subjected to CWIR for 2 hr, and then blood ...
Hui W M - - 1993
BACKGROUND: The mechanism by which epidermal growth factor (EGF) protects the gastric mucosa against injury is unclear. Whether EGF has any effect on gastric blood flow has not been reported. METHODS: Using an ex vivo gastric chamber preparation, the effect of EGF on gastric blood flow in rats was studied ...
Marais J - - 1993
The differing effects of halothane and isoflurane on nasal mucosal blood-flow was investigated by means of laser-doppler flowmetry in a total of fourteen patients who received one of these inhalational agents during anaesthesia. A trend towards lower nasal flux was seen in the halothane group but, due to insufficient numbers, ...
Alemayehu A - - 1993
The effects of a thromboxane A2 (TxA2)-endoperoxide analogue, U-44069 (0.16 micrograms/min. i.a.) on blood flows to the total wall, the mucosal (= mucosa+submucosa), and muscularis (= muscularis+serosa) layers of the canine jejunum, were determined utilizing radiolabelled microspheres (diam = 13.75 microns). U-44069 significantly decreased total (-64 +/- 5%), mucosal (-67 ...
Iwao T - - 1993
We measured regional gastric mucosal blood flow by laser Doppler flowmetry before and after control (n = 8) or cigarette smoking (n = 8) in healthy human beings. The control group showed no change in both antrum (from 1.15 +/- 0.32 to 1.20 +/- 0.39 V, NS) and corpus gastric ...
Lugea A - - 1993
Mild irritation of the rat duodenum enhances mucosal resistance to acid via a prostaglandin-mediated mechanism. Prostaglandins increase mucosal blood flow, but it is not known whether such changes in blood flow significantly contribute to adaptive cytoprotection. We induced blood flow changes by manipulating the arginine-nitric oxide pathway, which is independent ...
Iwao T - - 1993
We evaluated the reliability (i.e. reproducibility and variability) in measuring regional gastric mucosal blood flow by laser Doppler flowmetry in a total of 32 subjects (12 normal subjects and 20 patients with cirrhosis). The measurements were performed in quadruplicate within 10 min by observer A (A1, A2) and B (B1, ...
Niv Y - - 1993
It has been shown that the transient increase in total body bicarbonate that accompanies any acceleration of gastric acid secretion (the 'alkaline tide') is derivable from the associated changes in base excess in arterial blood and is precisely equivalent to the amount of acid secreted when the latter is simultaneously ...
Gislason H - - 1993
This study was designed to test the hypothesis that hyperemia after exposure to 2 M NaCl protects the gastric mucosa against damage caused by absolute ethanol by removing ethanol diffusing from the gastric lumen into the mucosa. The stomach of anesthetized cats was perfused with saline at pH 1.0. Gastric ...
Bende M - - 1993
Periodic oscillations of blood in the microcirculation of the sinus mucosa in the rabbit were studied with laser-Doppler flowmetry after the application of nose drops (oxymetazoline, xylometazoline and phenylephrine) to the nasal mucosa. All of these drugs induced a dose-dependent decrease in the blood flow in the mucosa. Flowmotion was ...
Taha A S - - 1993
Using laser Doppler flowmetry, we measured gastric and duodenal mucosal blood flow in 70 patients who had taken non-steroidal anti-inflammatory drugs (NSAIDs) for longer than 4 weeks, and studied the correlation with demographic factors, ulceration, and Helicobacter pylori. Blood flow was also measured in 17 other subjects not taking any ...
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