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Ariyarajah Vignendra - - 2008
Abnormal atrial depolarization, characterized by P waves >or=110 ms on the electrocardiogram, can manifest as partial or advanced interatrial conduction delay or interatrial block (IAB). Progression from partial to advanced IAB has been shown to be altered by the use of angiotensin-converting enzyme inhibitors and beta-adrenergic blockers. We previously reported ...
Pshenichnov Igor - - 2007
We study the spatial distributions of beta(+)-activity produced by therapeutic beams of (3)He and (12)C ions in various tissue-like materials. The calculations were performed within a Monte Carlo model for heavy-ion therapy (MCHIT) based on the GEANT4 toolkit. The contributions from positron-emitting nuclei with T(1/2) > 10 s, namely (10,11)C, ...
Sundaram Sri - - 2008
This study was designed to assess autonomic effects on the QT interval during recovery from exercise. Exercise is associated with an acute increased risk of sudden cardiac death. Evidence of impaired parasympathetic activity, such as low heart rate variability and heart rate recovery, and an increased QT interval are also ...
Delehaye Emilio - - 2008
OBJECTIVE: Deferoxamine therapy in lifelong transfusion-dependent anaemias, as beta-thalassemia major, is associated with an increased risk of ototoxic changes. With increasing survival rates, prevention and/or early detection of ototoxicity are important for providing management options. The predictive value of pure-tone audiometry in early detection of ototoxicity has been questioned, particularly ...
Phillips M D - - 2008
To examine the influence of acute resistive exercise and "hormone status" on cytokine profile, 35 postmenopausal women (72 +/- 6.2 yr) underwent a moderate-high-intensity resistive exercise bout or rested. There were 4 groups: no hormone replacement (NHR, n = 9), hormone replacement (HRT, n = 12), selective estrogen receptor modulator ...
Moraes Helena - - 2007
Exercise has been widely related to changes in cortical activation and enhanced brain functioning. Quantitative electroencephalography (qEEG) is frequently used to investigate normal and pathological conditions in the brain cortex. Therefore, the aim of the present study was to observe absolute power alterations in beta and alpha frequency bands after ...
Mink Steven N - - 2007
We previously showed that lysozyme (Lzm-S), derived from leukocytes, caused myocardial depression in canine sepsis by binding to the endocardial endothelium to release nitric oxide (NO). NO then diffuses to adjacent myocytes to activate the cGMP pathway. In a canine right ventricular trabecular (RVT) preparation, Lzm-S also decreased the inotropic ...
Holycross Bethany J - - 2007
Previous studies demonstrated an enhanced beta(2)-adrenoceptor (AR) responsiveness in animals susceptible to ventricular fibrillation (VF) that was eliminated by exercise training. The present study investigated the effects of endurance exercise training on beta(1)-AR and beta(2)-AR expression in dogs susceptible to VF. Myocardial ischemia was induced by a 2-min occlusion of ...
Dufour Doiron Monique - - 2007
The aim of this study was to investigate the effect of a beta-blocker (atenolol and metoprolol) on exercise heart rate (HR) and rate pressure product (RPP) during a morning and afternoon maximal exercise test (maxET) in patients with coronary heart disease (CHD). Twenty-one CHD patients (59.9 +/- 8.9 years of ...
Stob Nicole R - - 2007
Habitually exercising adults demonstrate greater thermogenic responsiveness to beta-adrenergic receptor (beta-AR) stimulation compared with their sedentary peers, but the molecular mechanisms involved are unknown. To determine the possible role of increased beta-AR density, we studied 32 healthy adults: 17 habitual aerobic exercisers (age 45 +/- 5 years, 11 males) and ...
Leosco Dario - - 2007
Cardiac beta-adrenergic receptor (beta-AR) signaling and left ventricular (LV) responses to beta-AR stimulation are impaired with aging. It is shown that exercise and beta-AR blockade have a favorable effect on cardiac and vascular beta-AR signaling in several cardiovascular diseases. In the present study, we examined the effects of these two ...
Rosso Rafael - - 2007
BACKGROUND: The mainstay of therapy for catecholaminergic polymorphic ventricular tachycardia (CPVT) is maximal doses of beta-blockers. However, although beta-blockers prevent exercise-induced ventricular tachycardia (VT), most patients continue to have ventricular ectopy during exercise, and some studies report high mortality rates despite beta-blockade. OBJECTIVE: The purpose of this study was to ...
Bender Tamás - - 2007
Beta-endorphin (betaE) is an important reliever of pain. Various stressors and certain modalities of physiotherapy are potent inducers of the release of endogenous betaE to the blood stream. Most forms of exercise also increase blood betaE level, especially when exercise intensity involves reaching the anaerobic threshold and is associated with ...
Dobbins C - - 2007
Purpose Radiofrequency ablation (RFA) is a popular method of treating unresectable liver tumours by the use of a high-frequency, alternating electrical current that heats and destroys tumour cells. The size of the ablation produced is limited by localised charring of adjacent tissue that prevents further conduction of the radiofrequency current. ...
Stob Nicole R - - 2007
The thermic effect of food (TEF) is an important physiological determinant of total daily energy expenditure (EE) and energy balance. TEF is believed to be mediated in part by sympathetic nervous system activation and consequent beta-adrenergic receptor (beta-AR) stimulation of metabolism. TEF is greater in habitually exercising than in sedentary ...
Böning Dieter - - 2007
Defense of extracellular pH constancy against lactic acidosis can be estimated from changes (Delta) in lactic acid ([La]), [HCO(3)(-)], pH and PCO(2) in blood plasma because it is equilibrated with the interstitial fluid. These quantities were measured in earlobe blood during and after incremental bicycle exercise in 13 untrained (UT) ...
Viru A A Institute of Exercise Biology, University of Tartu, Tartu, - - 2007
This study evaluated the influence of adrenergic factors on the cortisol response to maximal exercise in endurance-trained men. This was achieved by testing healthy young men during exercise while varying both the condition of beta-adrenergic blockage and the presence of a well-controlled simulated competitive environment to simulate activity of the ...
Shibakusa Tetsuro - - 2007
We have recently reported that inhibition of transforming growth factor (TGF)-beta in the brain reduced fat-related energy substrates concentrations in response to exercise. We investigated the relevance between the mobilization of fat-related energy substrates (nonesterified fatty acid and ketone bodies) during exercise and the effects of TGF-beta in the brain. ...
Dong Zeyuan - - 2007
It has long been known that tellurium compounds are rather toxic to living organisms, and tellurium has not been found in natural biomacromolecules to date. The principles of telluride toxicity in biological processes are still controversial partly because of the lack of information on the biochemical features of tellurium. In ...
Nieminen T - - 2007
Timolol maleate is a non-selective beta-adrenoceptor antagonist currently used mainly as an ocular preparation for the treatment of glaucoma and ocular hypertension. Despite the topical administration, ophthalmic timolol causes systemic adrenergic beta-blocking because of absorption from the eye into the systemic circulation. Gel formulations of ophthalmic timolol have been developed ...
Kitamura Hiromi - - 2007
Stressful exercise has been found to reduce the proinflammatory cytokine response to lipopolysaccharide (LPS). In this study, we aimed to determine whether receptor antagonists for corticosterone or catecholamines would increase the LPS-induced tumor necrosis factor-alpha (TNF-alpha) response after exhaustive exercise. Female F344 rats were randomly assigned to one of five ...
Lucats L - - 2007
BACKGROUND AND PURPOSE: Postsystolic wall thickening (PSWT) is part of thickening that occurs after end-systole and represents wasted effort as it does not contribute to ejection. The effects of antianginal drugs on PSWT remain to be established. We compared the effects on PSWT of two agents that reduce heart rate, ...
An Lawrence C - - 2006
High rates of Internet use among young adults make online intervention with this population particularly attractive. However, low adherence rates limit the exposure to and the potential effectiveness of these programs. This study identifies strategies for increasing adherence by examining the rates of participation for a 5-week beta (pilot) version ...
Stout J R - - 2007
This study examined the effects of 28 days of beta-alanine supplementation on the physical working capacity at fatigue threshold (PWCFT), ventilatory threshold (VT), maximal oxygen consumption (VO2-MAX), and time-to-exhaustion (TTE) in women. Twenty-two women (age+/-SD 27.4+/-6.1 yrs) participated and were randomly assigned to either the beta-alanine (CarnoSyn) or Placebo (PL) ...
Crabbe James B - - 2007
We examined the effects of 30 min of cycling exercise at a moderate intensity of 50% peak oxygen uptake, compared to 30 min of rest, on changes in emotional responses to pictorial foreground stimuli that reliably elicit unpleasant, neutral, and pleasant affect. Emotional responses were measured by self-reports of valence ...
Bishop David - - 2007
The regulation of intracellular pH during intense muscle contractions occurs via a number of different transport systems [e.g., monocarboxylate transporters (MCTs)] and via intracellular buffering (beta m(in vitro)). The aim of this study was to investigate the effects of an acute bout of high-intensity exercise on both MCT relative abundance ...
Rossini P M - - 2006
Objective. Can quantitative electroencephalography (EEG) predict the conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD)? Methods. Sixty-nine subjects fulfilling criteria for MCI were enrolled; cortical connectivity (spectral coherence) and (low resolution brain electromagnetic tomography) sources of EEG rhythms (delta=2-4 Hz; theta=4-8 Hz; alpha 1=8-10.5 Hz; alpha 2=10.5-13 Hz: ...
Haney Sarah - - 2006
Until recently, researchers believed that tolerance or tachyphylaxis to the bronchodilator effects of beta-agonists did not occur. However, recent studies examining the recovery from bronchoconstriction have clearly shown that an impaired response to beta-agonists occurs in patients who have been using regular beta-agonist treatment. This tolerance develops with both long- ...
Zoeller R F - - 2007
The effect of beta-alanine (beta-Ala) alone or in combination with creatine monohydrate (Cr) on aerobic exercise performance is unknown. The purpose of this study was to examine the effects of 4 weeks of beta-Ala and Cr supplementation on indices of endurance performance. Fifty-five men (24.5 +/- 5.3 yrs) participated in ...
Rimoldi Ornella E OE MRC Clinical Sciences Centre, Hammersmith Hospital, Du Cane Road, London, W12 0NN, - - 2007
Positron emission tomography (PET) studies in patients with diabetic autonomic neuropathy (DAN) have demonstrated the impact of this disease on cardiac sympathetic innervation and myocardial blood flow (MBF). To investigate the effects of selective partial sympathetic denervation of the left ventricle (LV) on baseline and hyperaemic MBF, we measured myocardial ...
Tenero David M - - 2006
To determine whether the controlled-release (CR) formulation of carvedilol given once daily provides 24-hour beta1-receptor blockade similar to the currently marketed immediate-release (IR) formulation given twice daily, changes in exercise-induced heart rate after bicycle ergometry were measured. The pharmacokinetic (PK)/pharmacodynamic (PD) relation between S(-)-carvedilol concentration-the enantiomer with beta-blocking activity-and change ...
Hara Hideyuki - - 2006
INTRODUCTION: Ventricular repolarization abnormalities are thought to contribute to lethal ventricular arrhythmias in patients with idiopathic dilated cardiomyopathy (DCM). The purpose of this study was to evaluate exercise-induced T wave changes in DCM patients before and after beta-blocker therapy to investigate repolarization abnormalities. METHODS AND RESULTS: Treadmill exercise testing was ...
Delgado Silvia Marcela - - 2006
Both peripheral innervation and nitric oxide (NO) participate in ovarian steroidogenesis. The purpose of this work was to analyse the ganglionic adrenergic influence on the ovarian release of steroids and NO and the possible steroids/NO relationship. The experiments were carried out in the ex vivo coeliac ganglion-superior ovarian nerve (SON)-ovary ...
Huang Robert L - - 2006
Therapeutic target with beta blockers in heart failure, i.e., target heart rate reduction or beta-blocker dose, is controversial. To resolve this controversy, the authors studied 152 heart failure patients on beta blockers who were divided into four groups based on median peak exercise heart rate reduction as compared with predicted ...
Wolfel Eugene E - - 2006
Cardiopulmonary exercise testing (CPET) has been used for the assessment of severity of heart failure (HF), secondary to left ventricular systolic dysfunction. Initial studies determined that oxygen consumption (VO2) during exercise, as a measure of functional capacity, correlated well with the hemodynamic responses related to chronic HF. These studies led ...
Sandblom Erik - - 2006
The role of the alpha-adrenergic system in the control of cardiac preload (central venous blood pressure; P(ven)) and venous capacitance during exercise was investigated in rainbow trout (Oncorhynchus mykiss). In addition, the antihypotensive effect of the renin-angiotesin system (RAS) was investigated during exercise after alpha-adrenoceptor blockade. Fish were subjected to ...
Beitelshees A L - - 2006
Two common polymorphisms in the beta1-adrenergic receptor gene, Ser49Gly and Arg389Gly, are associated with variable antihypertensive response to metoprolol. We sought to determine whether similar pharmacogenetic associations were present with the negative chronotropic response phenotype to metoprolol. Metoprolol was titrated in 54 untreated hypertensive patients to achieve blood pressure control. ...
Ahmad Kamran - - 2006
PURPOSE OF REVIEW: The aim of this article is to provide a perspective on rate control in atrial fibrillation which emphasizes patient wellbeing (exercise tolerance, symptoms, quality of life) over attempts to reduce resting or exercise heart rate to an arbitrary range. RECENT FINDINGS: Recent trials of rhythm versus rate ...
Kohut M L - - 2006
Increased serum levels of inflammatory mediators have been associated with numerous disease states including atherosclerosis, Type II diabetes, hypertension, depression, and overall mortality. We hypothesized that a long-term exercise intervention among older adults would reduce serum inflammatory cytokines, and this reduction would be mediated, in part, by improvements in psychosocial ...
Aschenbach William G - - 2006
beta-catenin is a multifunctional protein involved in cell-cell adhesion and the Wnt signaling pathway. beta-Catenin is activated upon its dephosphorylation, an event triggered by Dishevelled (Dvl)-mediated phosphorylation and deactivation of glycogen synthase kinase-3beta (GSK-3beta). In skeletal muscle, both insulin and exercise decrease GSK-3beta activity, and we tested the hypothesis that ...
Barbier Julie - - 2006
We investigated the effects of exercise training on heart rate variability (HRV) and myocardial adrenergic and muscarinic receptors in rats. Exercise training induced a decrease in body mass while ventricular size remained unchanged, a development we considered as a relative cardiac hypertrophy. In addition, there was a reduction in the ...
Goodstadt L L MRC Functional Genetics Unit, Parks Road, Oxford OX1 3QX, - - 2006
There is a well-characterized membrane chloride current (ICl,cAMP) in the heart that can be activated by beta-adrenergic agonists and is due to expression of the cardiac isoform of the epithelial cystic fibrosis transmembrane conductance regulator (CFTR). We have investigated whether 17beta-estradiol (E2) modulates ICl,cAMP in single ventricular myocytes. Under whole-cell ...
Uzuki Mitsuru - - 2006
Intraabdominal sepsis can lead to acute respiratory failure, and concomitant diaphragmatic dysfunction may be aggravated by sepsis-induced airway hyperreactivity. We previously reported that isoproterenol, a nonselective beta-adrenoceptor agonist, increased diaphragmatic contractility and accelerated recovery from fatigue during sepsis. The purpose of this study was to demonstrate the direct inotropic effect ...
Leineweber Kirsten K Department of Nephrology, University of Essen Medical School, - - 2006
In vitro, Arg389Gly beta1-adrenoceptor (AR) polymorphism exhibits decreased beta-AR signalling. In vivo, beta1-AR-mediated cardiac effects of exercise showed no genotype-dependent differences in Arg389 vs. Gly389 beta1-AR subjects. We studied in 16 male subjects homozygous Arg389 or Gly389 beta1-AR, whether blockade of parasympathetic activity might unmask genotype-dependence of exercise effects. Subjects ...
Billman George E - - 2006
Enhanced cardiac beta(2)-adrenoceptor (beta(2)-AR) responsiveness can increase susceptibility to ventricular fibrillation (VF). Exercise training can decrease cardiac sympathetic activity and could, thereby, reduce beta(2)-AR responsiveness and decrease the risk for VF. Therefore, dogs with healed myocardial infarctions were subjected to 2 min of coronary occlusion during the last minute of ...
Abdulla Jawdat - - 2006
The results of randomised control trials (RCTs) evaluating the effect of beta-blockers on functional status in patients with chronic heart failure are conflicting. To perform a systematic review and meta-analysis of RCTs evaluating the effect of beta-blockers on New York Heart Association (NYHA) classification and exercise tolerance in chronic heart ...
Ogasawara Junetsu - - 2006
The effect of exercise on beta-adrenergic receptor (beta-AR) trafficking was investigated in rat adipocytes. The binding sites of a hydrophilic ligand, [(3)H]CGP12177, increased immediately (0 h) and at 3 h after exercise (3 h) but decreased at 24 h after exercise (24 h). The data of immunoblotting revealed that the ...
Koutedakis Yiannis - - 2005
PURPOSE: Obesity has an etiology that is multidimensional in nature. Given the dearth of longitudinal data, we examined changes in adipose tissue (Ad) in relation to physical activity levels (PA), aerobic fitness (AF), and energy intake (EI) in Greek schoolchildren, as they progressed from age 12 to 14 yr. METHODS: ...
Bell Christopher - - 2006
Beta-adrenergic receptor (beta-AR) modulation of resting and postprandial energy expenditure (EE) is augmented in regularly exercising compared with sedentary adults, but the underlying physiological mechanisms are unknown. Differences in thermogenic responsiveness to beta-AR stimulation, perhaps secondary to reactive oxygen species (ROS) bioactivity, may be involved. To determine habitual exercise-related differences ...
Nozawa Takashi - - 2005
In patients routinely treated with metoprolol, influences of CYP2D6 genotype on the response of heart rate to isoproterenol (IP) were studied at its peak and trough concentrations and were compared with those of bisoprolol. In 72 patients treated with metoprolol or bisoprolol, CYP2D6 genotype (ie, CYP2D6*1, *2, *4, *5, *10, ...
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