Search Results
Results 201 - 250 of 1165
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Kaltman J R - - 2003
It has been proposed that beta-adrenergic antagonist protection against cardiac events in patients with long QT syndrome (LQTS) may be related to a decrease in baseline QTc dispersion. To determine the effects of beta-blocker therapy on QT measurements, we evaluated the exercise tests of 25 pediatric patients with LQTS. Measurements ...
Gómez-Tortosa Estrella - - 2003
BACKGROUND: Most patients with dementia with Lewy bodies (DLB) exhibit diffuse plaque-only pathology with rare neocortical neurofibrillary tangles (NFTs), as opposed to the widespread cortical neurofibrillary-tau involvement in Alzheimer disease (AD). Another pathological difference is the astrocytic and microglial inflammatory responses, including release of interleukins (ILs), around the neuritic plaques ...
Taniguchi Yasuyo - - 2003
BACKGROUND AND OBJECTIVES: The effects of beta-blocking agents on exercise tolerance in cardiopulmonary exercise testing (CPX) have not been fully identified. Because the negative chronotropic effects of these agents produce a sluggish increase in heart rate (HR) during CPX, exercise capacity is actually underestimated by methods that depend on HR-related ...
Maack Christoph - - 2003
Beta blockers have been shown to prolong survival in chronic heart failure. It is currently a matter of debate whether any beta blocker is superior to the other in terms of improving symptoms, left ventricular function, or prognosis. A number of comparative studies have been performed with metoprolol, a beta1-selective ...
Wonisch Manfred - - 2003
BACKGROUND: Exercise is recommended for cardiac patients irrespective of beta-blockers. Percentages of maximal heart rate (%HRmax) and heart rate reserve (%HRR) are widely used to determine training intensities. The purpose of this study was to investigate the influence of chronic cardioselective beta blockade on the %HRmax and %HRR model. METHODS: ...
Kraemer William J - - 2003
INTRODUCTION: It has been suggested that a proopiomelanocortin peptide beta-endorphin may play an important role in temperature regulation and therefore have specific heat stroke response patterns. METHODS: The purpose of this study was to examine the response patterns of plasma beta-endorphin at baseline, during a 7-d exercise-heat acclimation period (HA; ...
Lamont Linda S - - 2003
Exercising men, compared with women, have a greater increase in leucine oxidation but not lysine rate of appearance. The cause for this sexual dimorphism is unknown; however, an inhibition of beta-adrenoreceptor activity has previously been shown to mediate amino acid metabolism (Lamont LS, McCullough AJ, and Kalhan SC. Am J ...
Skarmoutsou Christophille - - 2003
BACKGROUND AND OBJECTIVES: Ferrokinetic studies and erythroid cell ultrastructural studies have indicated some degree of ineffective erythropoiesis in heterozygous beta-thalassemia, although a wide case-to-case variation was observed. In this study we applied rapid biochemical and hematologic measurements to assess erythroid marrow activity (sTfR) and reticulocyte hemoglobin content (CHr) in iron-sufficient ...
Brownley Kimberly A - - 2003
PURPOSE: This study examines the acute effects of moderate aerobic exercise on 1) hemodynamic and sympathetic activity during behavioral stress and 2) beta-adrenergic receptor responsivity in a biracial sample of 24 sedentary adults. METHODS: Before and after exercise, blood pressure (BP), impedance-derived cardiovascular measures, and plasma norepinephrine (NE) and epinephrine ...
Munagala Vijaya K - - 2003
BACKGROUND: Treadmill stress testing (TMST) is a valuable diagnostic test for ischemic heart disease. However, the inability to achieve the target heart rate because of either chronotropic incompetence or poor exercise capacity is a major limitation to its utility. We evaluated the usefulness of atropine in decreasing the number of ...
Yao Siu-Sun - - 2003
BACKGROUND: Dobutamine-atropine stress echocardiography (DASE) is an established test for the diagnosis and risk stratification of patients with coronary artery disease. Atropine use to attain target heart rate prolongs test time. HYPOTHESIS: The aim of this study was to assess the utility of isometric handgrip exercise (33% maximal voluntary contraction ...
Convertino Victor A - - 2003
We studied hemodynamic responses to alpha- and beta-receptor agonists in eight men to test the hypothesis that adrenoreceptor responsiveness is altered within 24 h of the performance of maximal exercise. Adrenoreceptor responsiveness was tested under two experimental conditions (with and without maximal exercise). Adrenoreceptor tests were performed 24 h after ...
Bailey Damian M - - 2003
There is no direct evidence to support the contention that contracting skeletal muscle and/or associated vasculature generates free radicals in exercising humans. The unique combination of isolated quadriceps exercise and the measurement of femoral arterial and venous free radical concentrations with the use of electron paramagnetic resonance (EPR) spectroscopy enabled ...
Calabrò Luana - - 2003
Angiogenesis contributes to disease progression in solid and hematopoietic malignancies, and endoglin (CD105), a component of the transforming growth factor (TGF)-beta receptor complex, is a powerful marker of neovascularization. Elevated amounts of soluble CD105 (sCD105) have been recently identified in selected solid tumors but no data are available on sCD105 ...
Herman Rahmatina B - - 2003
Evidence of long-term beneficial effects of beta-blockers on mortality and morbidity in patients with heart failure has been demonstrated in recent randomized trials. However, not all beta-blockers are identical. Carvedilol, a nonselective beta- and alpha-adrenergic blocker, can potentially blunt the release of noradrenaline by blocking presynaptic beta2-adrenergic receptors. To test ...
Faulhaber Martin - - 2003
Frequency of therapeutic beta-blocker use in elderly mountaineers is unknown. Therefore, the aim of this field study was to measure the regular beta-blocker intake in elderly persons visiting moderate altitudes. In a subset of mountaineers on beta-blockers, exercise response at two different altitude levels was compared to matched controls. The ...
Huang Chin-Wei - - 2003
BACKGROUND: For clinical treatment, a smaller dosage of propranolol is often used among Chinese people. Propranolol is metabolized by polymorphic CYP2D6. We postulate that the lower propranolol dosage in Chinese is due to a slower CYP2D6 metabolism. A majority of the Chinese population has the nucleotide T188 in the CYP2D6 ...
Spooner C H - - 2003
Exercise-induced bronchoconstriction (or asthma) following strenuous physical exertion is common and can cause sub-optimal performance, symptoms such as cough, dyspnea, wheeze, chest tightness, and can lead people to avoid physical activity. Management focuses on prevention with pre-exercise treatment using various pharmacologic agents. Mast cell stabilizing agents are effective in attenuating ...
Love Jeffrey N - - 2002
STUDY OBJECTIVE: We sought to characterize the ECG changes associated with symptomatic beta-blocker overdose. METHODS: The study population consisted of a prospective cohort of patients reporting to 2 regional poison centers with beta-blocker overdose. Each patient received an ECG on presentation and a structured follow-up. The inclusion criteria for symptomatic ...
Sviridov Dmitri - - 2003
Physical activity can raise the level of circulating HDL cholesterol. Pre beta 1-HDL is thought to be either the initial acceptor of cellular cholesterol or virtually the first particle in the pathway of the formation of HDL from apolipoprotein A-I and cellular lipids. We have therefore sought to identify pre ...
Hunter Angus M - - 2002
This study analysed the effect of selective beta(1)-blockade on neuromuscular recruitment characteristics during progressive endurance exercise. Ten healthy subjects ingested a selective beta(1)-blocker, acebutolol (200 mg b.d.), for 7 days (for one of two cycling trials), with a 10-day wash-out period between trials. On the last day of acebutolol ingestion ...
Herbert N A - - 2002
It is hypothesised that the visual performance of rainbow trout, Oncorhynchus mykiss, will be impaired by strenuous exercise as a result of metabolic stress (blood lactacidosis) that activates the Root effect and limits the oxygen-carrying capacity of blood flowing to the eye. The ability to resolve high contrast objects on ...
Okajima Masaki - - 2003
Shear stress-dependent nitric oxide (NO) formation prevents immoderate vascular constriction. We examined whether shear stress-dependent NO formation limits exercise-induced coronary artery constriction after beta-adrenergic receptor blockade in dogs. Control exercise led to increases (P < 0.01) in coronary blood flow (CBF) by 38 +/- 5 ml/min from 41 +/- 5 ...
Larsen Thomas M - - 2002
BACKGROUND: Stimulation of energy expenditure (EE) with selective thermogenic beta-adrenergic agonists may be a promising approach for treating obesity. OBJECTIVE: We analyzed the effects of the highly selective human beta(3)-adrenergic agonist L-796568 on 24-h EE, substrate oxidation, and body composition in obese, weight-stable men. DESIGN: In this 2-center, double-blind, randomized, ...
Harant I I Institut National de la Santé et de la Recherche Médicale (INSERM, Unité 317), Université Paul Sabatier, Toulouse, France. - - 2002
The aim of the study was to investigate whether a long-lasting bout of exercise modifies the lipolytic beta- and antilipolytic-alpha(2)-adrenergic effect and the antilipolytic effect of insulin in obese subjects. Biopsies of abdominal subcutaneous adipose tissue were performed before and immediately after 2 h exercise (at 50% of VO(2max)) on ...
Dunnett C E - - 2002
The aim of the present study was to relate changes in muscle oxidative capacity and free fatty acid flux in response to oil supplementation to fuel utilisation during subsequent exercise of varying intensities. Following 10 weeks of oil supplementation there was an increased capacity for fat utilisation during low and ...
Plecko Barbara - - 2002
In persistent hyperinsulinemic hypoglycemia of infancy, ketone body concentrations are abnormally low at times of hypoglycemia, depriving the brain of its most important alternative fuel. The neuroprotective effect of endogenous ketone bodies is evidenced by animal and human studies, but knowledge about exogenous supply is limited. Assuming that exogenous ketone ...
Janssen Paul M L - - 2002
OBJECTIVE: Increased levels of inhibitory G proteins have been observed in heart failure, but their physiological relevance in mediating the reduced beta-adrenergic response is largely unknown. METHODS: To evaluate the functional consequences of Galpha(i2) overexpression, we studied myocardial contraction in intact isometric contracting cardiac rabbit trabeculae and isolated myocytes after ...
Lurie Susan - - 2002
The rapidly ripening summer apple cultivar Anna was treated with 0.1 micro L(-1) and 1 microL L(-1) 1-methylcyclopropene (MCP) at harvest and kept at 20 degrees C, or stored for 5 weeks at 0 degrees C and then transferred to 20 degrees C. Total volatiles were not reduced by treatment ...
Lee Hyoung S - - 2002
Color changes in red grapefruit juice concentrates during storage at -23 degrees C for 12 months were studied. Concentrate (38 degrees Brix) was packed in both plastic (16 oz) and metal (6 oz) cans. Decrease in red intensity (CIE a) in juice color and slight increases in CIE L*, b*, ...
Gobbetti Anna - - 2002
The aim of the present work was to study the possible role of adenylate cyclase-activating polypeptide (PACAP) 38 in the testicular intracellular mechanism regulating steroidogenesis of crested newt, Triturus carnifex. Gonads were incubated in vitro with PACAP 38 and prostaglandin (PG) E(2) alone or with inhibitors of cyclooxygenase (COX), adenylate ...
Stewart William C - - 2002
PURPOSE: To compare the cardiovascular effects of unoprostone 0.15%, timolol 0.5% and placebo in healthy adults during exercise using a treadmill test. METHODS: Thirty subjects aged 18-37 years (mean age = 24.1 years) were randomized to one of six treatment sequences in a three-treatment, three-period crossover study (William's design). Study ...
Nowicki M - - 2002
Non-selective beta-adrenergic blockers may cause hyperkalemia in patients with end-stage renal failure. In contrast, alpha-adrenergic blockade has been found to decrease the hyperkalemic effect of physical exercise in healthy subjects, although we were unable to confirm this effect in hemodialysis patients. In a crossover design, we studied the effect of ...
Monmeneu Menadas J V - - 2002
BACKGROUND AND AIM OF THE STUDY: The study aim was to determine whether beta-blocker treatment (atenolol) improves cardiopulmonary exercise performance and ventilatory response in patients with mitral stenosis in sinus rhythm. METHODS: A prospective study comparing the results of cardiopulmonary exercise tests (CPETs) was performed before and after atenolol therapy ...
Stoschitzky Kurt - - 2002
In vitro studies have shown that beta-blockers are taken up into and released from adrenergic cells. As a consequence, plasma concentrations of beta-blockers increase during exercise together with those of epinephrine and norepinephrine. However, effects of exercise on plasma concentrations of (R)- and (S)-carvedilol are unknown. Twelve healthy males received ...
Arai Masanao - - 2002
To investigate the detailed actions of transforming growth factor-beta (TGF-beta) in the brain, which increase accompanied with continuity of exercise, the authors performed electroencephalogram (EEG) spectral analysis for 2 h after intracranial injection of TGF-beta in rats and compared with the effects of swimming exercise. Relative power values (power percent) ...
Courneya Kerry S - - 2002
In this study, we examined correlates of adherence and contamination in a randomized controlled trial (RCT) of exercise in cancer survivors using the theory of planned behavior and the Five Factor Model of personality (FFM). We randomly assigned cancer survivors in group psychotherapy classes to either a waiting-list control group ...
Güngör K - - 2002
Effects of mutations in the beta 2-adrenergic receptor (beta 2AR) gene on intraocular pressure (IOP), in response to acute dynamic exercise, were investigated in 19 healthy males (age 22.6 +/- 2.8 years). Intraocular pressures were measured pre- and post-exercise. Weight, height, body mass index, and maximal oxygen (VO2max) uptake were ...
Alon Tal - - 2002
Beta-hydroxy-beta-methylbutyrate, more commonly referred to as HMB, is derived from the amino acid, leucine, and its keto acid, alpha-ketoisocaproate. In several studies combining HMB supplementation and resistance exercise, researchers have concluded that HMB may play an important role in reducing protein degradation and/or increasing recovery of damaged muscle cells. These ...
Brull D J - - 2002
We have examined the effect of two beta-fibrinogen gene promoter polymorphisms (-455G>A and -854G>A) on the fibrinogen response to severe exercise in a group of male army recruits undergoing basic training. Fibrinogen was measured pre-training and again serially after severe 48 h final military exercise (FME). Out of 884 subjects, ...
Stoschitzky Kurt - - 2002
In vitro studies have shown that beta-blockers are taken up into and released from adrenergic cells together with epinephrine and norepinephrine. Consequently, studies in humans revealed an increase in plasma concentrations of propranolol and atenolol during physical exercise. However, carvedilol has not been investigated in a similar fashion. Eleven hypertensive ...
Jamurtas A Z - - 2001
The aim of this study was to determine whether beta-endorphin infusion influences liver or muscle glycogen concentration during exercise. Thirty-two rats (Harlan Co., IN, USA) with a body mass of 265-290 g were assigned at random to four groups, each of eight rats: (1) beta-endorphin infusion for 90 min at ...
Aubert B - - 2001
We present the results of searches for B decays to charmless two-body final states containing eta(') or omega mesons, based on 20.7 fb(-1) of data collected with the BABAR detector. We find the branching fractions Beta(B(+)-->eta(')K(+)) = (70+/-8+/-5) x 10(-6), Beta(B(0)-->eta(')K(0)) = (42(+13)(-11) +/- 4) x 10(-6), and Beta(B(+)-->omega pi(+)) ...
Angelopoulos T J - - 2001
Nine highly fit men [mean (SE) maximum oxygen uptake, VO2max: 63.9 (1.7) ml x kg(-1) x min(-1); age 27.6 (1.6) years] were studied during two treadmill exercise trials to determine plasma beta-endorphin immunoreactivity during intense exercise (80% VO2max). A double-blind experimental design was used, and subjects performed the two exercise ...
Wang T - - 2001
Reptiles, particularly snakes, exhibit large and quantitatively similar increments in metabolic rate during muscular exercise and following a meal, when they are apparently inactive. The cardiovascular responses are similar during these two states, but the underlying autonomic control of the heart remains unknown. We describe both adrenergic and cholinergic tonus ...
Ohuchi H - - 2001
BACKGROUND: Elevated neurohumoral activity and an abnormal cardiopulmonary response to exercise are well-established characteristics in patients after the Fontan operation. However, there have been few studies addressing cardiac autonomic nervous activity (CANA) in these patients. METHODS AND RESULTS: We evaluated CANA in 63 post-Fontan patients and 44 controls. Cardiac parasympathetic ...
Zarzeczny R - - 2001
BACKGROUND: This study examined the hypothesis that prolonged (12 hrs) stimulation of adrenergic receptors by adrenaline and their blockade by regitine (alpha-blockade) or propranolol (beta-blockade) affect lactate thresh-old (T(LA)) and exercise tolerance in rats. METHODS: Twenty-four untrained male Wistar rats performed a multistage running test on a treadmill with an ...
Le Mellédo J M - - 2001
OBJECTIVES: Review of the literature equivocally suggests that subjects with Type A behavioral pattern (TABP) compared to subjects with Type B behavioral pattern display an increased sympathetic activity, a condition associated with sudden cardiac death. The objective of this study was to determine whether healthy subjects classified as Type A ...
Júnior P B - - 2001
The aim of this study was to determine the relationship between blood lactate and glucose during an incremental test after exercise induced lactic acidosis, under normal and acute beta-adrenergic blockade. Eight fit males (cyclists or triathletes) performed a protocol to determine the intensity corresponding to the individual equilibrium point between ...
Bell C - - 2001
We recently demonstrated in young adult humans that the sympathetic nervous system contributes to the control of resting metabolic rate via tonic beta-adrenergic receptor stimulation. In the present follow-up study we determined the respective effects of age, habitual exercise status, and sex on this regulatory mechanism. Resting metabolic rate (ventilated ...
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