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Results 551 - 600 of 1813
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Summers Richard L - - 2004
Angiotensin-converting enzyme inhibitors, beta adrenergic blockers, and nesiritide are pharmacologic agents for heart failure with both short- and long-term neurohormonal and hemodynamic effects. Angiotensin-converting enzyme inhibitors and beta adrenergic blockers reduce morbidity and mortality in chronic heart failure. Higher doses may result in better outcomes than lower doses, but concern ...
Nollen G J - - 2004
OBJECTIVE: To investigate the heterogeneous response to beta blockade in patients with Marfan syndrome by non-invasive assessment of the aortic pressure-area curve. DESIGN AND PATIENTS: 25 patients with the Marfan syndrome who used beta blocking agents (mean (SD) age, 29 (10) years; 20 men, five women), seven without beta blockade ...
Iijima Takehiko - - 2004
PURPOSE: Pulse dye-densitometry, a novel monitor that measures circulating blood volume (CBV) and cardiac output (CO), was used in patients with pheochromocytoma to determine the relationship between CBV and post resection hypotension. METHODS: Case control study. An alpha blocker was administered for approximately two weeks, and its effect on the ...
Bale Tracy L - - 2004
Corticotropin-releasing factor (CRF) and its paralogues urocortin (Ucn)I, -II, and -III signal by activating their receptors, CRF receptors (CRFR)1 and -2, to maintain homeostasis through endocrine, autonomic, and behavioral responses. CRFR2 is found in cardiomyocytes and in endothelial and smooth muscle cells of the systemic vasculature. Echocardiography and cardiac catheterization ...
Layland Joanne - - 2004
PKA-dependent phosphorylation of cardiac troponin I (cTnI) contributes significantly to beta-adrenergic agonist-induced acceleration of myocardial relaxation (lusitropy). However, the role of PKA-dependent cTnI phosphorylation in the positive inotropic response to beta-adrenergic stimulation is unclear. We studied the contractile response to isoprenaline (10 nm) in isolated hearts and isolated cardiomyocytes from ...
Melgar-Fernández Roberto - - 2004
The synthesis of four novel analogues of metoprolol, a well-known beta1-blocker used to reduce arterial blood pressure, is described. The preparation of (2S,2'S)-7, (2R,2'S)-7, (2R,2'R)-8, and (2S,2'R)-8 was based on the reaction of racemic 2-[4-(2'-methoxyethyl)-phenoxymethyl]-oxirane (4) with (R)- or (S)-2-amino-1-butanol. Salient characteristics of analogues 7 and 8 relative to metoprolol ...
Milne Brian - - 2004
Consideration regarding human aging and sympathetic nervous system activity suggests that old age represents a hyperadrenergic state. With advancing age the sympathetically mediated stress on the body, specifically the cardiovascular system, may outweigh the benefits an intact sympathetic nervous system conveys for short-term survival. Beta blockers temper the effects of ...
Nürnberger Jens - - 2003
OBJECTIVE: Pulse wave velocity (PWV) is a classic marker of vascular stiffness. Recent studies showed that heart rate is an important determinant of PWV. The purpose of this study was to evaluate the role of myocardial function in determining PWV under resting conditions and under adrenergic stimulation. DESIGN AND METHODS: ...
Elizur Arnon - - 2003
Tracheal epinephrine (adrenaline) has been associated with two major deletorious side effects: increased heart rate (HR) and an initial decrease of blood pressure (BP). This prospective randomized animal study compared the haemodynamic responses to tracheally administered epinephrine or norepinephrine (nor adrenaline) alone versus each after pretreatment with propranolol for ameliorating ...
Chang Joseph J - - 2003
BACKGROUND: Widened pulse pressure is an independent predictor of cardiovascular outcomes in older persons. The purpose of this study was to examine the associations between antihypertensive medication class and the magnitude of pulse pressure among persons receiving treatment for hypertension in the third National Health and Nutrition Examination Survey. METHODS: ...
Papageorgiou Peter C - - 2004
"New pressor protein" (NPP) derived from normal human plasma is an extra renal enzyme that shares strong sequence homology with human coagulation beta-FXIIa. Under our bioassay conditions, human NPP (10-20 microl plasma equivalent/ approximately 300 g rat iv) can raise the systolic blood pressure (SBP) by 40-50 mmHg, the diastolic ...
Kooijman Miriam - - 2003
BACKGROUND: Supraspinal sympathetic control of leg vascular tone is lost in spinal cord-injured individuals, but this does not result in a reduced leg vascular tone: Leg vascular resistance is even increased. The aim of this study was to assess the alpha-adrenergic contribution to the increased vascular tone in the lower ...
Messerli Franz H - - 2003
Over the past decade, national and international guidelines have proposed beta-blockers to be used on an equal footing with diuretics for initial therapy of hypertension. This preferred status was supposedly based on evidence documenting a reduction in morbidity and mortality with beta-blocker therapy in hypertension. We systematically analyzed all available ...
Paluch M - - 2003
Dielectric spectra of the polyalcohols sorbitol and xylitol were measured under isobaric pressures up to 1.8 GPa. At elevated pressure, the separation between the alpha and beta relaxation peaks is larger than at ambient pressure, enabling the beta relaxation times to be unambiguously determined. Taking advantage of this, we show ...
Ubbink Dirk Th - - 2003
This study was undertaken to investigate the possible negative effect of beta-blockers on skin microcirculation in patients with intermittent claudication and hypertension. Methods and materials In this clinical crossover study, 20 patients with mild to moderate hypertension, treated with long-term beta-blockade, and intermittent claudication or ischemic rest pain, underwent assessment ...
Hryniewicz Katarzyna - - 2003
Adrenergic receptor blockers used in the treatment of heart failure have distinct receptor affinity profiles. We hypothesized that alpha-adrenergic-blocking effects of carvedilol would limit vasoconstriction in response to adrenergic stimuli when compared with metoprolol. Forearm vascular resistance responses to isometric handgrip and cold pressor test were determined by plethysmography before ...
Crossley Dane A DA - - 2003
Our understanding of avian embryonic cardiovascular regulation has been based on studies in chickens. The present study was undertaken to determine if the patterns established in chickens are generally applicable to the emu, a ratite bird species. We studied cardiovascular physiology over the interval from 60% to 90% of the ...
Lamarre-Cliche Maxime - - 2003
The QT interval corrected for heart rate (QTc) is believed to reflect sympathovagal balance. It has also been established that beta-blockers and dihydropyridine-type calcium channel blockers (DHPCCB) influence the autonomic nervous system. This study tested the hypothesis that QTc interval length is a predictor of the blood pressure reduction induced ...
Chi Dong-sheng - - 2003
OBJECTIVE: To investigate the value of the echocardiographic observation of the left ventricular hypertrophy (LVH) in diagnosing myocardial microvascular damage in patients with essential hypertension (EH). METHODS: After intravenous injection with Quanfuxian (a contrast agent consisting of albumin and C3F8 prepared by Nanfang Hospital), the values of A (the maximum ...
Snapir Amir - - 2003
Common naturally occurring polymorphisms have been identified in the coding regions of the alpha(1A)-, alpha(2B)-, beta(1)- and beta(2)-adrenoceptor (AR) genes [alpha(1A)-AR R492C, alpha(2B)-AR insertion/deletion (I/D), beta(1)-AR R389G, beta(2)-AR G16R and beta(2)-AR Q27E] and are associated with modified in vivo and in vitro functionality. We tested their possible effects on the ...
Schönauer Verena - - 2003
High factor VIII (FVIII) is a risk factor for venous thromboembolism (VTE). The pathomechanism by which high FVIII leads to an increased risk of VTE is unknown. Physical activity and infusion of adrenalin provoke a rise in FVIII, which can be blocked by a nonselective beta-blockade. We tested the hypothesis ...
Sofowora G G - - 2003
BACKGROUND: A common polymorphism of the beta(1)-adrenergic receptor Arg389Gly markedly affects function in vitro, but little is known about its in vivo significance. METHODS AND RESULTS: Resting and exercise hemodynamic responses were measured in subjects homozygous for Arg389 (n = 21) or Gly389 (n = 13) alleles before and 3 ...
Segers Patrick - - 2003
Maximal left ventricular (LV) hydraulic power output (PWR(max)), corrected for preload as PWR(max)/(V(ed))(beta) (where V(ed) is the end-diastolic volume and beta is a constant coefficient), is an index of LV contractility. Whereas preload-adjusted maximal power (PAMP) is usually calculated with beta = 2, there is uncertainty about the optimal value ...
Bonomi Francesco - - 2003
Bovine beta-lactoglobulin was hydrolyzed with trypsin or chymotrypsin before, during and after treatment at 600 MPa and pH 6.8 for 10 min at 30, 37 and 44 degrees C. The extent of beta-lactoglobulin hydrolysis under pressure was noticeably higher than at atmospheric pressure, particularly when chymotrypsin was used. Addition of ...
Gielerak Grzegorz - - 2003
BACKGROUND: A degree of reduction of heart rate (HR) and blood pressure (BP) values following beta-blocker administration has been shown to indicate beta-blockade effectiveness. Whether this parameter is also useful in the identification of patients with vaso-vagal syncope (VVS) who could benefit from beta-blocker therapy, has not yet been established. ...
Wang Xi - - 2003
Alterations in general characteristics and morphology of the heart, as well as changes in hemodynamics, myosin heavy chain isoforms, and beta-adrenoceptor responsiveness, were determined in Sprague-Dawley rats at 1, 2, 4, 8, and 16 wk after aortocaval fistula (shunt) was induced by the needle technique. Three stages of cardiac hypertrophy ...
Kleophas W - - 2003
AIMS: To assess the tolerability, safety and efficacy of the epoetin beta multidose cartridge formulation, self-administered subcutaneously via a pen device (Reco-Pen), in adult patients with renal anemia. METHODS: Patients receiving maintenance epoetin therapy were switched to the subcutaneous (SC) multidose formulation of epoetin beta (NeoRecormon). The frequency of adverse ...
Polska Elzbieta - - 2003
Recent studies indicate that the human choroid has a considerable capacity to keep blood flow constant despite exercise-induced increases in perfusion pressure. The mechanisms underlying this vasoconstrictor response remain unclear. We hypothesized that pharmacological modulation of the autonomic nervous system may alter the choroidal pressure/flow relationship during squatting. To test ...
Tuinstra T - - 2002
The authors used high and low responders to novelty (HRs and LRs, respectively) to examine the effects of noradrenergic injections into the nucleus accumbens using a special radial-maze task. During the 5 successive test days, solvent-treated HRs acquired this task faster than LRs. Isoproterenol (beta-agonist) combined with phenylephrine (alpha-agonist) improved ...
Grossman Ehud - - 2002
Despite the fact that beta-blockers have been used for the treatment of hypertension for more than 30 years, no study has shown that their use reduces morbidity and mortality in the elderly. To the contrary, the British Medical Research Council trial in the elderly documented that although blood pressure was ...
Veldhuijzen van Zanten Jet J C S - - 2002
This study examines the effects of competition and competitiveness on hemodynamics. Cardiovascular activity was measured in 27 men at resting baseline and during a car racing game, which comprised a solo race against time and three races against an experimenter. To assess hematocrit, blood was collected at rest and after ...
Molenaar Peter - - 2002
OBJECTIVE: The goal of this study was to determine whether the cardiostimulant effects of the endogenous beta(1)-adrenergic receptor (AR) agonist, (-)-norepinephrine are modified by polymorphic (Serine49Glycine [Ser49Gly], Glycine389Arginine [Gly389Arg]) variants of beta(1)-ARs in the nonfailing adult human heart. BACKGROUND: Human heart beta(1)-ARs perform a crucial role in mediating the cardiostimulant ...
Metra Marco - - 2002
We compared the hemodynamic effects of dobutamine and enoximone administration before and after long-term beta-blocker therapy with metoprolol or carvedilol in patients with chronic heart failure (HF). Patients with HF on beta-blocker therapy may need hemodynamic support with inotropic agents, and the hemodynamic response may be influenced by both the ...
Mavrogiannis Louie - - 2002
OBJECTIVE: To investigate the major cardiovascular effects of human plasma "new pressor protein" (NPP) and how the adrenal medulla contributes to these effects. METHODS: NPP was injected into bioassay rats intravenously, and the effects on blood pressure and cardiac function were investigated. Acute adrenal medullectomy (2MDX), alpha- and beta-adrenergic blockade ...
Melis Maria G - - 2002
The beta(3)-adrenergic receptor (beta(3)AR) plays a critical role in lipid metabolism, and thus alterations in its function may be involved in the metabolic syndrome. Indeed, we have found previously that the Trp64Arg amino acid variant of the beta(3)AR is associated with hypertension and higher serum triacylglycerol levels in the Sardinian ...
Martin Deana Desmarais - - 2002
The identity and amounts of intracellular solutes in the deep-sea bacterium Photobacterium profundum strain SS9 were studied using nuclear magnetic resonance techniques. P. profundum strain SS9, a moderate piezophile which grows optimally at 20-30 MPa primarily accumulated glutamate and betaine, with lesser amounts of alanine, beta-hydroxybutyrate (beta-HB) and oligomers composed ...
Huke Sabine - - 2002
In this study we evaluated the contractile characteristics of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA)1a-expressing hearts ex vivo and in vivo and in particular their response to beta-adrenergic stimulation. Analysis of isolated, work-performing hearts revealed that transgenic (TG) hearts develop much higher maximal rates of contraction and relaxation than wild-type (WT) hearts. ...
Inaba M - - 2002
The present study was undertaken to assess the effect of hyperthyroidism on stiffness in the common carotid artery (CCA) in patients with Graves' disease (GD) and elucidate the mechanism by which arterial stiffness is increased in hyperthyroidism. The arterial stiffness index beta (stiffness beta) was evaluated in the CCA using ...
Johansson Kristina - - 2002
1. The aim of the present study was to investigate the effects of alpha-adrenoceptor blockade (phentolamine), beta-adrenoceptor blockade (propranolol), neuropeptide Y(1) receptor blockade and neurogenic blockade (brachial plexus) on endothelium-dependent vasodilation (EDV) in the human forearm. 2. Forty-four young healthy volunteers underwent forearm blood flow (FBF) measurements, using venous occlusion ...
Rokosh D Gregg - - 2002
alpha 1-adrenergic receptors (ARs) play a major role in blood pressure regulation. The three alpha 1-AR subtypes (A/C, B, and D) stimulate contraction of isolated arteries, but it is uncertain how different subtypes contribute to blood pressure regulation in the intact animal. We studied the role of the alpha 1A/C ...
Ohte Nobuyuki - - 2002
In patients with myocardial infarction (MI), an expansion of the remote normal regions of the left ventricle is often observed. However, the characteristics of such regions are not fully understood. Thus, we investigated this issue from the standpoint of myocardial oxidative metabolism using (11)C-acetate PET. METHODS: In 33 patients with ...
Barenblatt G I - - 2002
According to a model of the turbulent boundary layer that we propose, in the absence of external turbulence the intermediate region between the viscous sublayer and the external flow consists of two sharply separated self-similar structures. The velocity distribution in these structures is described by two different scaling laws. The ...
Cleophas T J - - 2002
BACKGROUND: Baroreflex sensitivity declines with age, creating a fall in systolic blood pressure and pulse pressure when standing. If, in addition, blood pressure is reduced as a result of antihypertensive medication, compensatory mechanisms may be inadequate and orthostatic problems may occur. This may be less true in patients on beta-blockers. ...
Eckhart Andrea D - - 2002
Cardiovascular regulation is tightly controlled by signaling through G protein-coupled receptors (GPCRs). beta-Adrenergic receptors (ARs) are GPCRs that regulate inotropy and chronotropy in the heart and mediate vasodilation, which critically influences systemic vascular resistance. GPCR kinases (GRKs), including GRK2 (or betaARK1), phosphorylate and desensitize agonist-activated betaARs. Myocardial GRK2 levels are ...
van Baak Marleen A - - 2002
OBJECTIVE: Our objective was to investigate the thermogenic efficacy of single oral doses of the novel beta(3)-adrenergic receptor agonist L-796568 [(R )-N -[4-[2-[[2-hydroxy-2-(3-pyridinyl)ethyl]amino]ethyl]-phenyl]-4-[4-[4-(trifluoromethyl)phenyl]thiazol-2-yl]-benzenesulfonamide, dihydrochloride] in humans. METHODS: Twelve healthy overweight to obese men participated in this 2-center, 3-period, randomized, placebo-controlled, crossover trial. In each period subjects received 250 mg L-796568, ...
Hassanzadeh M - - 2002
The present study was carried out to determine, first, the cardiac beta-adrenergic receptor characteristics of broiler chick embryos exposed to two different CO(2) levels during the last stage of embryonic development, and second, the prophylactic effect of beta(1)-adrenoceptor blocker on right ventricular hypertrophy in broiler chickens. High CO(2) embryos showed ...
Bagi Per - - 2002
The urethral response to a sudden forced dilation was studied in ten healthy male volunteers aged from 27 to 71 years. Measurements were performed from the bladder neck and beyond the region of high pressure using a specially designed probe. The pressure response after dilation showed a characteristic course, which ...
Bagi Per - - 2002
The significance of the anatomical location and age on the urethral response to a sudden forced dilation was studied in 30 healthy males aged 23-85 years. The pressure decay after dilation was fitted with a double exponential function of the form: P(t) = P(equ) + P(alpha)e(-t/tau(alpha) + P(beta)e(t/tau(beta) where P(t) ...
Szabó Gábor - - 2002
BACKGROUND: This study investigated the changes of catecholamine responsiveness and beta-adrenergic receptor/adenylyl cyclase pathway during acute cardiac transplant rejection. METHODS: Isogeneic Lewis to Lewis and allogeneic Dark Agouti (DA) to Lewis rat cardiac transplants were studied 3 and 5 days after heterotopic intraabdominal transplantation (n=6/group). Myocardial blood flow (MBF), left ...
Badorff Cornel - - 2002
Congestive heart failure is a leading cause of mortality in developed countries. Myocardial hypertrophy resulting from hypertension often precedes heart failure. Understanding the signaling underlying cardiac hypertrophy and failure is of major interest. Here, we identified Fas receptor activation, a classical death signal causing apoptosis via activation of the caspase ...
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