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Results 301 - 350 of 1197
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Ring C - - 2000
The mechanism underlying acute changes in secretory immunoglobulin A (sIgA) remains to be determined. In this experiment, sIgA and cardiovascular activity were monitored at rest and while participants performed a mental arithmetic task, cold pressor, and submaximal cycle exercise following placebo or 1 mg of the alpha-adrenergic blocker, doxazosin. Under ...
Ide K - - 2000
A reduced ability to increase cardiac output (CO) during exercise limits blood flow by vasoconstriction even in active skeletal muscle. Such a flow limitation may also take place in the brain as an increase in the transcranial Doppler determined middle cerebral artery blood velocity (MCA V(mean)) is attenuated during cycling ...
Popp P - - 2000
Concentrations of tetrachlorobenzenes, pentachlorobenzene, hexachlorobenzene and alpha-, beta-, gamma- and delta-HCH in air and deposition were measured at three different contaminated sites in Greppin, Roitzsch (both near Bitterfeld) and Leipzig during five time intervals of 14 days in the summer months of 1998. The mean values of the chlorobenzene concentrations ...
Jamurtas A Z - - 2000
Beta-endorphin (betaE) bolus (0.05 mg x kg(-1)) infusion (0.05 mg x kg(-1) x h(-1)) was previously shown in rats to attenuate the decline in plasma glucose during exercise. PURPOSE: The present investigation compared betaE and saline infusion in rats without a bolus of betaE to determine whether 1) the attenuation ...
Geor R J - - 2000
To examine the role of beta-adrenergic mechanisms in the regulation of endogenous glucose (Glu) production [rate of appearance (R(a))] and utilization [rate of disappearance (R(d))] and carbohydrate (CHO) metabolism, six horses completed consecutive 30-min bouts of exercise at approximately 30% (Lo) and approximately 60% (Hi) of estimated maximum O(2) uptake ...
de Beer E L - - 2000
Crossbridge dynamics underlying the acute and chronic inotropic effects of doxorubicin (Dox) were studied by application of releasing length steps (amplitude, 0.5-10%) to skinned cardiac trabeculae. Acute incubation of trabeculae with 20 microM Dox for 30 min resulted in a decrease of the velocity of unloaded shortening (V(0), from 9.3 ...
Rasool A H - - 2000
OBJECTIVE: To determine whether racial differences in response to blockade of beta receptors occur among racial groups in Malaysia that are the Malays, Indians and Chinese. SUBJECTS, MATERIALS AND METHOD: 35 healthy male volunteers representing the 3 main racial groups in Malaysia (12 Malays, 12 Chinese and 11 Indians) were ...
Matthys D - - 2000
PURPOSE: Beta-adrenergic blockade increases blood ammonia concentration during exercise. The purpose of this study was to assess the role of decreased carbohydrate availability in this process. METHODS: Wistar rats (N = 47) were injected intravenously with a selective beta 2-adrenoceptor blocker (ICI 118,551), placebo, or beta 2-blocker + glucose 1 ...
Kikuchi M - - 2000
The present study of coherence analysis, in 16 healthy male volunteers, aged 24-31 years, showed that the administration of 0.25 mg of scopolamine significantly reduced interhemispheric coherence in the delta and beta-1 bands in the resting state. Scopolamine also caused a significant increase both in EEG coherence during PS and ...
Smith K E - - 2000
The insecticidal effects of the phenylpyrazole, fipronil, and a pyrethroid, beta-cyfluthrin, on larvae of the blowfly Lucilia sericata were determined in laboratory assays. When first stage larvae of L. sericata were reared on homogenized pig liver which had been treated with known amounts of test compounds, both fipronil and beta-cyfluthrin ...
Ishii Y - - 2000
Systemic adverse effects of timolol ophthalmic solution given at usual therapeutic doses have been well characterized. Timolol is partially metabolized by cytochrome P450 (CYP) 2D6. Cimetidine inhibits the activity of cytochrome P450, including CYP2D6, leading to reduced systemic clearance of concomitant drugs. Coadministration of cimetidine has been speculated to affect ...
Nordmann J P - - 2000
AIMS: To compare the effect on intraocular pressure (IOP) of latanoprost monotherapy and timolol-pilocarpine in patients with glaucoma or ocular hypertension with inadequately controlled IOP on topical beta adrenergic antagonists. METHODS: This was a multicentre, randomised, observer masked, 6 week study performed in France and Sweden. 23 centres enrolled 237 ...
Vanhees L - - 2000
OBJECTIVES: To compare the effects of a highly beta1-selective adrenoceptor antagonist bisoprolol with those of atenolol and placebo on endurance exercise capacity in young, healthy male volunteers. DESIGN: Twelve subjects randomly received oral placebo, atenolol (100 mg/day) or bisoprolol (10 mg/day) for 3 weeks, following a double-blind cross-over design. METHODS: ...
Weltzien F A - - 2000
Body content of beta-hydroxybutyrate, and individual dry mass, carbon content, and survival rate, were studied in developing nauplii of the brine shrimp Artemia franciscana K. from hatching to 96-97 h post hatching at 27 +/- 1 degrees C. The effect of two diets was studied in the experiment: Super Selco ...
Segal J B - - 2000
Our goal was to determine what drugs are most efficacious for controlling the ventricular rate in patients with atrial fibrillation. We conducted a systematic review of the literature published before May 1998, beginning with searches of The Cochrane Collaboration's CENTRAL database and MEDLINE. We included English-language articles describing randomized controlled ...
Bramlett S B - - 1999
We investigated the effect of a single bout of exercise on leptin mRNA levels in rat white adipose tissue. Male Sprague-Dawley rats were randomly assigned to an exercise or control group. Acute exercise was performed on a rodent treadmill and was carried out to exhaustion, lasting an average of 85.5 ...
Antonelli G - - 1999
The development of neutralizing antibodies (NAbs) to interferon (IFN) is a common phenomenon of IFN beta therapy for relapsing-remitting multiple sclerosis (RRMS) patients. Here we examine the specificity of NAbs developed during therapy for RRMS with recombinant interferon (rIFN) beta-1a or rIFN beta-1b, and study the effect of switching from ...
Vassilakopoulos T - - 1999
Interleukin-1beta (IL-1beta) and interleukin-6 (IL-6), powerful stimulants of the hypothalamic-pituitary-adrenal (HPA) axis, increase in response to whole body exercise. Strenuous inspiratory resistive breathing (IRB), a form of clinically relevant "exercise" for the respiratory muscles, produces beta-endorphin through a largely unknown mechanism. We investigated (in 11 healthy humans) whether strenuous IRB ...
Stich V - - 1999
The involvement of the antilipolytic alpha(2)-adrenergic pathway and the specific role of epinephrine in the control of lipolysis during exercise in adipose tissue (AT) were investigated in healthy male subjects (age: 24.1 +/- 2.2 yr; body mass index: 23.0 +/- 1.6). An in vitro study carried out on isolated adipocytes ...
Skanchy D J - - 1999
In this research the separation of the enantiomers of the basic drug bidisomide (SC-40230) from five closely related known process impurities was investigated using several neutral and anionic sulfobutylether beta-cyclodextrins (SBE-beta-CDs) as isomer selectors. Several novel sulfobutylether derivative mixtures and purified charge types having a specific degree of substitution were ...
Paroo Z - - 1999
The response to exercise stress is characterized by an increase in circulating catecholamines and rapid synthesis of the inducible member of the 70 kDa family of heat shock proteins (Hsp70). Cell culture studies indicate that Hsp70 expression is influenced by beta-adrenergic receptor intermediates including cyclic AMP (cAMP) and cAMP dependent ...
Winzer A - - 1999
We investigated the influence of sympathetic nervous system processes on mucosal immunity by comparing the effects of beta-adrenoceptor blockade with 40 mg propranolol and placebo on secretory immunoglobulin A (sIgA) at rest and during paced serial arithmetic, cold pressor, and submaximal cycling. These tasks produced patterns of cardiovascular activity indicative ...
Marquet P - - 1999
A placebo and a low and a high dose of dexamethasone (Dex) were administered for 4.5 days, at 3-wk intervals, to 24 healthy men, following a double-blind, random-order, crossover procedure. After the last dose the subjects performed a maximal cycling exercise, during which respiratory exchanges, electrocardiogram, and blood pressures were ...
Meyer W R - - 1999
OBJECTIVE: To examine the interaction between circulating beta-endorphin levels and sex steroids during sustained submaximal exercise in runners who are either anovulatory and oligomenorrheic (AO) or ovulatory and eumenorrheic (EO). DESIGN: Controlled clinical study. SETTING: General clinical research center at an academic medical center. PATIENT(S): Three AO and four EO ...
Neuman I - - 1999
BACKGROUND: The unicellular alga Dunaliella bardawil was previously shown to contain very high concentrations of beta-carotene composed of equal amounts of the all-trans and 9-cis stereoisomers which differ in their physicochemical features and antioxidative activity. Due to the controversy regarding the beneficial effect of antioxidants on asthma, the acute effects ...
Stewart W C - - 1999
The purpose of this study was to evaluate the effect of timolol hemihydrate 0.5% (Betimol [THH], Ciba Vision Ophthalmics) and timolol maleate gel forming solution 0.5% (Timoptic-XE , [TXE], Merck, Inc.), when both are dosed once daily on the exercise performance. Maximum exercise heart rate reflects systemic beta-blockade activity. Fourteen ...
Mills P J - - 1999
Exercise induces a selective redistribution of CD62L(-) T lymphocytes. This study examined the effects of beta adrenergic receptor blockade on this phenomenon. Twelve healthy men were exercised to exhaustion on a treadmill prior to and following 1 week of treatment with the nonselective beta antagonist propranolol or the beta1 selective ...
Summers R L - - 1999
Nebulized beta 2-receptor agonists may cause neutrophil demargination and result in misleading total circulating leukocyte counts (WBCs) in patients with acute bronchospasm. Varying underlying adrenergic stimulation in these patients also makes interpretation of these data difficult. This study examined the direct effect of these agents on the measured WBCs of ...
Prichep L S - - 1999
This study investigates the existence of outcome related neurophysiological subtypes within a population of abstinent cocaine dependent adults. We have previously reported and replicated the existence of a distinctive quantitative EEG (QEEG) profile in such a population, and demonstrated the persistence of this pattern at one and six month follow-up ...
Wade M E - - 1999
BACKGROUND: The purpose of this experiment was to examine the effects of both exercise and beta-adrenergic receptor blockade on the expression of native cardiac myosin isoforms. Specifically, this experiment tested two hypotheses: 1) treatment of sedentary rats with the beta blocker, propranolol, will promote increased ventricular V3 (slow) native myosin ...
Tarasiuk A - - 1999
OBJECTIVE: In dogs, scorpion venom evokes a rapid increase in cardiac output (CO) that decreases below baseline level in 1 hr. The changes in CO have recently been shown to be related to the effect of the venom on venous return. In the present study, we tested the hypothesis that ...
Head A - - 1999
The rationale for the concurrent prescription of beta-blockers and programmes of exercise is that both medication and physical activity can improve the quality of life of patients with cardiovascular disease. Difficulties arise when drugs reduce either the physical ability or the motivation to exercise. This article focuses on the physiological ...
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 ...
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