Search Results
Results 301 - 350 of 1165
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Raby C A - - 1998
The beta-amyloid peptides, A beta1-42 and A beta1-40, were quantified in ventricular CSF taken daily for up to 3 weeks from six individuals with severe traumatic brain injury (TBI). There was considerable interindividual variability in the levels of A beta peptides, but in general A beta1-42 levels equalled or exceeded ...
Li Y - - 1998
Combined treatment of allograft recipients with anti-CD40 ligand and CTLA-4Ig (costimulation blockade) is a powerful promising albeit not consistently tolerizing therapy. It would be desirable to use an effective conventional immunosuppressive regimen in low doses or for a short course as an adjunct; however, cyclosporine treatment drastically blunts the ability ...
Børsheim E - - 1998
The purpose of this study was to characterize the effects of prolonged beta-adrenoceptor stimulation on O2 uptake and triglyceride/fatty acid (TG/FA) cycling during rest with and without previous exercise. Eight men performed two exercise (90 min cycling at 56 +/- 3 (SD)% of maximal O2 uptake, followed by 4.5 h ...
Bandi J C - - 1998
Physical exercise increases portal pressure (hepatic venous pressure gradient [HVPG]) in patients with cirrhosis. It is unknown if this deleterious effect is associated with changes in gastroesophageal collateral blood flow and if these can be prevented by propranolol administration. The aim of this study was to characterize the effects of ...
Brynne L - - 1998
The concentration-effect relationship of l-propranolol and dl-metoprolol were investigated in spontaneous hypertensive rats using reduction in exercise-induced tachycardia as a pharmacodynamic endpoint. The influence of protein binding on the effect relationship was also assessed. The rats were assigned to treatment or placebo groups, where each group received three randomly selected ...
Mäki T - - 1998
To elucidate the mechanism of alcohol-induced atrial fibrillation (AF) we studied the heart rate variability and parameters of the adrenergic system during alcohol intake, hangover, and exercise in 6 men (mean age 43 years) prone to alcohol-induced AF, together with 6 age-matched controls. The ambulatory (15 hour) electrocardiogram was recorded ...
Velázquez H - - 1998
BACKGROUND: Although the renal cortical collecting duct (CCD) is a principal target for aldosterone, recent evidence suggests that salt transport by other nephron segments may also be regulated by aldosterone. Electroneutral and thiazide-sensitive NaCl cotransport by the distal convoluted tubule (DCT) of the rat is increased in animals deprived of ...
Lehmann M - - 1998
PURPOSE: The parasympathetic, Addison type, overtraining syndrome represents the dominant modern type of this syndrome. Beside additional mechanisms, an autonomic or neuroendocrine imbalance is hypothesized as underlying. METHODS/RESULTS: Several findings support this thesis. During heavy endurance training or overreaching periods, the majority of findings give evidence of a reduced adrenal ...
al-Khalili F - - 1998
BACKGROUND: A variety of vascular effects have been ascribed to 17 beta-oestradiol. These effects may partially explain the reduced incidence of cardiovascular disease found in post-menopausal women on oestrogen replacement therapy. OBJECTIVES: To evaluate the effects of 2 mg sublingual 17 beta-oestradiol on exercise capacity, exercise-induced myocardial ischaemia and circulating ...
Duncker D J - - 1998
To date, no studies have investigated coronary vasomotor control of myocardial O2 delivery (MDO2) and its modulation by the autonomic nervous system in the porcine heart during treadmill exercise. We studied 8 chronically instrumented swine under resting conditions and during graded treadmill exercise. Exercise up to 85% to 90% of ...
Lukaszyk A - - 1998
The objective of this study was to determine whether endogenous EFG released after submaximal physical exercise, affects platelet-endothelium interactions. Sixteen healthy male volunteers, aged 23-26 years, were submitted to a submaximal bicycle ergometry test. Blood for determination of EGF concentrations, platelet function studies (concentrations of beta-TG, PF4 and TXB2) and ...
Kadish A H - - 1998
BACKGROUND: Prior studies on the effects of propranolol on human ventricular refractoriness have yielded occasionally inconsistent results. Most prior studies have examined refractory periods at a single stimulus intensity and without using continuous pacing; thus, the effects of propranolol on repolarization may have not been completely defined. The purpose of ...
Børsheim E - - 1998
In the recovery period after strenuous exercise, there is increased O2 uptake, termed the excess postexercise O2 consumption (EPOC). One of the mechanisms suggested to explain EPOC is activation of the triglyceride/fatty acid (TG/FA) cycle by catecholamines. The purpose of this study was to determine the effect of selective beta1- ...
Rohrer D K - - 1998
beta 1-Adrenergic receptors (beta 1-ARs) are key targets of sympathetic nervous system activity and play a major role in the beat-to-beat regulation of cardiac chronotropy and inotropy. We employed a beta 1-AR gene knockout model to test the hypothesis that beta 1-AR function is critical for maintenance of resting heart ...
Marathe P H - - 1998
OBJECTIVE: To assess whether a clinically significant change in the pharmacokinetics of avitriptan and propranolol is observed in healthy subjects after coadministration of the two drugs. METHODS: The pharmacokinetics of avitriptan and propranolol were investigated when the two drugs administered separately and when two 150 mg doses of avitriptan 2 ...
Børsheim E - - 1998
After strenuous exercise there is a sustained increase in resting O2 consumption. The magnitude and duration of the excess post-exercise O2 consumption (EPOC) is a function of exercise intensity and exercise duration. Some of the mechanisms underlying the rapid EPOC component (<1 h) are well defined, while the mechanisms causing ...
Lipka E - - 1998
The objective of this study was to investigate the absorption mechanism of celiprolol as a potential source of the drug's non-linear oral pharmacokinetics by determining its intestinal permeability as a function of concentration in vivo in dogs. Solutions of different celiprolol concentrations containing propranolol as an internal absorption marker were ...
Ross J J - - 1998
An important interaction between beta-adrenergic receptor (AR) stimulation and the myocardial contractile response to increased heart rate has only recently been identified. The effect of beta-AR stimulation to amplify the force-frequency effect is responsible for a large component of the positive inotropic effect of exercise in conscious dogs and also ...
González O - - 1998
The effects of exercise stress on erythrocyte beta-adrenergic receptor characteristics and plasma concentrations of adrenaline, noradrenaline and thyroid hormones were studied in Thoroughbred racehorses during rest and after exercise. Five minutes after a maximal speed race of 1200 +/- 200 m (mean +/- s.d.), both plasma adrenaline and noradrenaline concentrations ...
Stubenitsky R - - 1997
1. To date no study has described the cardiovascular effects of increased myofilament Ca2+ responsiveness in awake animals both under resting conditions and during treadmill exercise. In the present study we therefore investigated the systemic, pulmonary and coronary haemodynamic actions of the Ca2+ sensitizer EMD 57033 in 16 chronically instrumented ...
Sumida S - - 1997
We investigated the effects of acute exhaustive exercise and beta-carotene supplementation on urinary 8-hydroxy-deoxyguanosine (8-OHdG) excretion in healthy nonsmoking men. Fourteen untrained male (19-22 years old) volunteers participated in a double blind design. The subjects were randomly assigned to either the beta-carotene or placebo supplement group. Eight subjects were given ...
Wada T - - 1997
It has been demonstrated that cultured mesangial cells (MC) express latent transforming growth factor (TGF)-beta binding protein (LTBP) mRNA, and that LTBP might be essential for the extracellular matrix (ECM) accumulation stimulated by TGF-beta in cultured MC. We performed a study to test the pathophysiological role of LTBP in mesangial ...
Nieto J L - - 1997
beta-Adrenergic mechanisms may be important in the adaptation of skeletal muscle to endurance training. beta-Adrenergic signal transduction was examined in the gastrocnemius muscle of rats submitted to a progressive, 12-week treadmill running program and compared with sedentary controls. beta-Adrenoceptor density was significantly lower in exercised rats than in controls. The ...
Takase B - - 1997
To investigate the effects of carteolol, which is a nonselective beta-adrenergic agent with intrinsic sympathomimetic activity, on silent myocardial ischemia, exercise-induced myocardial ischemia, indexes of heart rate variability, and pain-modulating system, 20 patients (mean 60 +/- 9 years) with chronic stable angina underwent exercise treadmill testing and 24-hour ambulatory electrocardiographic ...
Coker R H - - 1997
The role of catecholamines in the control of hepatic glucose production was studied during heavy exercise in dogs, using a technique to selectively block hepatic alpha- and beta-adrenergic receptors. Surgery was done > 16 days before the study, at which time catheters were implanted in the carotid artery, portal vein, ...
Vea H - - 1997
Beta-adrenergic sensitivity and counterregulatory hormone and symptomatic responses to hypoglycaemia were studied in a 22-year-old man before and 3 and 34 weeks after removal of an insulinoma. The beta-adrenergic sensitivity was measured by the effect of an isoprenaline infusion on the heart rate, and the dose needed to increase the ...
Mier C M - - 1997
We sought to determine whether 10 days of training would be a sufficient stimulus for cardiac adaptations that would allow a greater compensatory stroke volume during beta-blockade. We also sought to determine whether men and women had a similar cardiac reserve capacity for increasing stroke volume with beta-blockade during submaximal ...
Jilma B - - 1997
BACKGROUND: Until now the effects of beta-adrenergic agonists have largely been ascribed to their ability to induce intracellular formation of cyclic adenosine monophosphate. Recently evidence has been accumulating that at least some beta1 and beta2-adrenoceptor effects may be mediated by nitric oxide (NO). Based on these studies, we hypothesized that ...
Noppen M M - - 1997
In patients with essential hyperhidrosis (EH), a pathological condition characterized by increased activity of the upper dorsal sympathetic ganglia D2-D3, anatomical interruption at the D2-D3 level by thoracoscopic sympathicolysis (TS) is a safe and effective treatment. The D2 and D3 ganglia, however, are also in the pathway of sympathetic lung ...
Shields L E - - 1997
Currently little is known about the cardiovascular responses of the anemic fetus to neuromuscular blockade. We hypothesized that, despite marked anemia with potentially decreased cardiac reserve, the fetal responses to Pancuronium neuromuscular blockade would differ significantly when compared with neuromuscular blockade with Atracurium (a cardiovascular sparing agent). Ten fetal sheep ...
Guo Z - - 1997
We previously found that epinephrine, a mixed beta- and alpha-adrenoreceptor agonist, stimulates systemic and nonsplanchnic upper body free fatty acid (FFA) release but not lower body FFA release in healthy nonobese women. To evaluate the role of beta-adrenergic-mediated effects on this regional difference in lipolysis, we measured systemic, leg, and ...
Goldfarb A H - - 1997
beta-Endorphin, a 31-amino-acid peptide, is primarily synthesised in the anterior pituitary gland and cleaved from pro-opiomelanocortin, its larger precursor molecule. beta-Endorphin can be released into the circulation from the pituitary gland or can project into areas of the brain through nerve fibres. Exercise of sufficient intensity and duration has been ...
Lamont L S - - 1997
This was a randomized, cross-over experiment designed to determine which beta-adrenergic receptors, beta 1, beta 2, or both, regulate metabolic rate in humans. All subjects (3 women, 4 men) were administered a 7-d therapeutic dose of a selective beta 1-antagonist (atenolol 50 mg BID), a combined beta 1, beta 2-antagonist ...
Carlsen K H - - 1997
The present randomized, double-blind placebo-controlled study aimed at investigating the possible improvement in endurance performance caused by inhaled salmeterol (long-acting beta 2-agonist) and salbutamol (short-acting) compared to placebo in 18 healthy well-trained athletes, aged 17-30 years old. Lung function (flow-volume loops) was measured before and after each inhaled study drug ...
Head A - - 1997
OBJECTIVE: Previous studies have shown that beta 1 selective agents have fewer adverse effects on exercise metabolism than nonselective beta blockers, and this has been attributed to their reduced blockade of beta 2 receptors. This study aimed at determining whether a beta blocker with partial agonist activity at beta 1 ...
Fujii N - - 1997
Competitive reverse transcription-polymerase chain reaction (RT-PCR) analysis was used to clarify whether dynamic exercise-induced increases in beta-adrenergic-receptor (beta-AR) number in human lymphocytes are accompanied by increases in the beta-AR mRNA level. Sixteen healthy subjects performed cycle ergometry until exhaustion. Before and immediately after exercise, peripheral blood was drawn from a ...
Todd M K - - 1997
This study compared the effects of exercise or TXB2 and beta-TG when evaluated by four methods: 1) not adjusted; 2) adjusted for plasma volume changes (PV); 3) standardized per 10(5) platelets (PC); 4) or both PC and PV (PC-PV). Blood was collected from 16 men (41.3 +/- 8.1 yr) at ...
Lipworth B J - - 1997
Regular treatment with both long- and short-acting beta 2-agonists results in tolerance to their bronchoprotective effects, although the relevance of this phenomenon in terms of long term asthma control remains unclear. However, there appears to be no appreciable difference between the 2 long-active beta 2-agonists, salmeterol and formoterol, in their ...
Cook C J - - 1997
Measurements of neurotransmitters in conscious animals have been restrictive in real-time. The use of specific enzymes within an amperometric probe, based upon a microdialysis membrane, may overcome some of these problems. I report the use of such a probe, with different perfusions of enzymes, to allow real-time measurement of glutamate, ...
Li S - - 1997
The object of this experiment is to study the autonomic nervous control of alpha responses elicited in classical conditioning. Twenty-two mongrel dogs were trained in classical discriminative conditioning. Typical two-phase tachycardic responses were observed in positive (CS+) trials while only the earliest, phase 1, response was observed in negative (CS-) ...
Bhatia S C - - 1997
Bipolar concentric electrodes were implanted in extreme lateral regions of hypothalamus having coordinates (A12.5 mm, L 3.5-3.7 mm, V 3.0-3.7 mm). These sites were electrically stimulated using biphasic square wave pulses (1 ms, 60 Hz) at a current strength ranging from 300-800 microA to evoke predatory attack on an anaesthetized ...
de Miguel T - - 1997
Four wild-type species of the genus Rhodosporidium have been studied as as possible sources for the industrial production of beta-carotene. HPLC-based studies showed that their carotenoid composition consisted of almost pure beta-carotene at concentrations ranging from 226 to 685 micrograms/g of dried yeast biomass. These results are consistent with those ...
Böttcher M - - 1997
The beta 1 receptor blockade reduces cardiac work and may thereby lower myocardial blood flow (MBF) at rest. The effect of beta 1 receptor blockade on hyperemic MBF is unknown. METHODS: To evaluate the effect of selective beta 1 receptor blockade on MBF at rest and during dipyridamole induced hyperemia, ...
Drummond P D - - 1997
The effect of adrenergic blockade on vascular responses in the forehead was assessed during stressful mental arithmetic, singing, and moderate exercise in 21 frequent blushers and 21 infrequent blushers. Adrenergic antagonists were introduced into a small site on the forehead by iontophoresis, and vascular responses were monitored bilaterally with laser ...
Pacifici G M - - 1997
1. Salbutamol as a beta 2-adrenergic agonist used in the treatment of lung obstructive disease and premature labour. It has a bioavailability of 50% and sulphation is the main route of its metabolism. (-)-Salbutamol retains most of the beta 2-adrenergic activity and, thereby, we describe the interindividual variability in the ...
Eagles C J - - 1997
AIMS: We examined the effects of different combinations of beta 1-selective adrenoceptor blockers and lipid-lowering drugs, on fat metabolism and fatigue during moderate intensity exercise in 14 healthy young volunteers. METHODS: The study was a randomized crossover design, each subject completing 5, 90 min walks at 50% of predetermined maximal ...
Silke B - - 1997
A double-blind, randomized, placebo-controlled comparison of metoprolol (50 mg) and celiprolol (200 mg) was undertaken in nine normal volunteers. Rest and exercise (supine bicycle) hemodynamics were assessed at 0, 2, 4, 6, and 8 hours following single oral doses of medication administered at weekly intervals. The influence of the ancillary ...
Mosha T C - - 1997
The alpha-carotene, beta-carotene and total provitamin A carotenoids and the effect of traditional processing practices on the retention of these provitamins were studied using amaranth, cowpea, peanut, pumpkin and sweet potato leaves. Results of this study indicated that the content of total carotenoids, beta-carotene and alpha-carotene were in the range ...
Weston A R - - 1997
Skeletal muscle buffering capacity (beta m), enzyme activities and exercise performance were measured before and after 4 weeks of high-intensity, submaximal interval training (HIT) undertaken by six well-trained competitive cyclists [mean maximal oxygen consumption (VO2max) = 66.2 ml.kg-1.min-1]. HIT replaced a portion of habitual endurance training and consisted of six ...
Perna G P - - 1997
OBJECTIVE: To determine whether the net release of beta-endorphin during exercise, similar to that of norepinephrine, is related to functional disability in patients with congestive heart failure. BACKGROUND: Plasma beta-endorphin and norepinephrine levels are elevated at rest in patients with heart failure, reflecting a functional disability. The net release of ...
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