Search results for "Flux"
showing 10 items of 1392 documents
On the Number of Measurements Necessary to Assess Regional Cerebral Blood Flow by Local Laser Doppler Recordings: A Simulation Study with Data from 4…
1995
Laser Doppler fluxmetry may improve the monitoring of cortical blood flow in neurosurgical patients. So far, however, the variability of laser Doppler readings found in the cerebral cortex has prevented a consequent usage of the technique in clinical practice. The current report analyzes the regional variability of laser Doppler readings from experimental animals. Typical frequency histograms of observed flow values display non-Gaussian distributions. A simulation technique is used to assess the number of measuring sites required for valid estimates of regional cortical flow. From a total of 990 local flow measurements from 45 rabbits random samples of sizes between 5 and 100 were repeatedl…
PS01.057: THYROIDECTOMY AND LARYNGO-PHARYNGEAL REFLUX: WHAT’S NEW
2018
Abstract Background ‘Local neck symptoms’ may be related to goiter; a persistence of those symptoms after an uncomplicated total thyroidectomy (TT) might be referred to the laryngo-pharyngeal reflux (LPR). Our previous study found a correlation between goiter and LPR in selected patients with local neck symptoms; the purpose of our current study is to investigate the presence of a laringopharyngitis in patients with goiter, before and after TT, even in the absence of local neck symptoms, assessing whether the presence of LPR may play a role at the outset of the symptomatology. Methods Two groups of patients were considered and they differred for the presence or absence of local neck symptom…
Fructose 2,6-bisphosphate and glycolytic flux in skeletal muscle of swimming frog
1990
AbstractGlycolytic flux in skeletal muscle is controlled by 6-phosphofructokinase but how this is achieved is controversial. Brief exercise (swimming) in frogs caused a dramatic increase in the phosphofructokinase activator, fructose 2,6-bisphosphate, in working muscle. The kinetics of phosphofructokinase suggest that in resting muscle, the enzyme is inhibited by ATP plus citrate and that the increase in fructose 2,6-bisphosphate is part of the mechanism to activate phosphofructokinase when exercise begins. When exercise was sustained, fructose 2,6-bisphosphate in muscle was decreased as was the rate of lactate accumulation. Glycolytic flux and the content of fructose 2,6-bisphosphate appea…
Duodenogastrischer Reflux nach Vagotomie und Pyloroplastik
1976
Bei 27 Patienten mit selektiver oder trunkularer Vagotomie und Pyloroplastik wurde gepruft, ob ein duodenogastrischer Reflux vorliegt. Die Untersuchung erfolgte rontgenologisch durch Instillation von verdunntem Bariumbrei in das Duodenum und durch Nachweis von i.v. appliziertem Bromsulphalein im Magensaft. Es konnte bei 20 von 23 Patienten rontgenologisch und bei 18 von 27 Patienten durch den Bromsulphalein-Nachweis ein duodenogastrischer Reflux festgestellt werden. In Zusammenhang mit Reflux standen postoperative Beschwerden wie Vollegefuhl, Brechreiz und Oberbauchschmerzen, sowie der Nachweis morphologischer Veranderungen der Magenschleimhaut im Sinne von Gastritiden verschiedener Stadien.
An exploratory study of two Caco-2 cell models for oral absorption: A report on their within-laboratory and between-laboratory variability, and their…
2010
In 2005, the European Centre for the Validation of Alternative Methods (ECVAM) sponsored a study aimed at evaluating the reproducibility (between-laboratory and within-laboratory variability) and the predictive capacity of two in vitro cellular systems — the Caco-2/ATCC parental cell line and the Caco-2/TC7 clone — for estimating the oral fraction absorbed (Fa) in humans. Two laboratories, both of which had experience with Caco-2 cultures, participated in the study. Ten test chemicals with documented in vivo oral absorption data were selected. Atenolol, cimetidine and propranolol were included as reference compounds for low, medium and high intestinal absorption, respectively. Transport ex…
Delayed-Onset Superior Mesenteric Artery Syndrome Presenting as Oesophageal Peptic Stricture
2012
Superior mesenteric artery (SMA) syndrome is an infrequent cause of vomiting and weight loss due to compression of the third part of the duodenum by the SMA. We describe the case of a 17-year-old woman, admitted to our department for progressive dysphagia and severe weight loss due to an oesophageal peptic stricture, caused by chronic acid reflux secondary to duodenal compression by the SMA. Symptoms improved after (par)enteral nutrition and repeated oesophageal dilatation, thus supporting the role of intensive medical and endoscopic intervention as an alternative to surgery, at least in some cases.
Do we understand the pathophysiology of GERD after sleeve gastrectomy?
2020
Gastroesophageal reflux disease (GERD), a prevalent problem among obese individuals, is strongly associated with obesity and weight loss. Hence, bariatric surgery effectively improves GERD for many patients. Depending on the type of bariatric procedure, however, surgery can also worsen or even cause a new onset of GERD. As a consequence, GERD remains a relevant problem for many bariatric patients, and especially those who have undergone sleeve gastrectomy (SG). Affected patients report not only a decrease in physical functioning but also suffer from mental and emotional problems, resulting in poorer social functioning. The pathomechanism of GERD after SG is most likely multifactorial and tr…
Differential effects of hypothermia on neuronal efflux, release and uptake of noradrenaline
1972
Isolated rabbit hearts were perfused at 34° (control), 24° or 12°C. The neuronal efflux of noradrenaline after perfusion with the amine for 1 h was depressed at 24° C (Q 10 about 5) in the presence or absence of desipramine; at 12°C the efflux was below the limit of estimation. Moderate reduction of the temperature (24° C) decreased the removal of perfused noradrenaline to about 60% of the control value and caused a 1.7-fold increase of the output of noradrenaline evoked by sympathetic nerve stimulation. It is concluded that the extremely temperature-dependent efflux of noradrenaline across the axonal membrane is not part of the release of noradrenaline evoked by nerve stimulation.
Characterization of choline efflux from the perfused heart at rest and after muscarine receptor activation.
1986
The resting efflux of choline from perfused chicken hearts varied from 0.4 to 2.6 nmol/g min, but was constant for at least 80 min in the individual experiments. The rate of choline efflux was found to be equal to the rate of choline formation in the heart, which, from the following reasons, was essentially due to hydrolysis of choline phospholipids. Cardiac content of choline phospholipids (7,200 nmol/g) was much higher than that of acetylcholine (5.5 nmol/g). Resting release of acetylcholine was 0.016 nmol/g min and, after inhibition of cholinesterase, only about 0.1 nmol/g min. Resting efflux of choline was reduced by mepacrine, a phospholipase A2 inhibitor, by perfusion with a Ca2+-free…
Stimulation of calcium uptake by norepinephrine or high external potassium in human calyces and renal pelvis.
1989
The effects of stimulation with either 10 mumol/l norepinephrine or 85 mmol/l extracellular potassium concentration on calcium uptake were studied in muscle strips from human renal calyces and from the renal pelvis. The apparent uptake of calcium under control conditions was essentially complete after 30 min. Stimulation of the muscle strips with norepinephrine or high external potassium significantly (P less than 0.05) increased the calcium uptake over the control values at 30 and 100 min, whereas 45Ca efflux was virtually not affected. It is concluded that the mechanical responses of the muscle strips to norepinephrine or high external potassium correspond with an increased uptake of calc…