Search Results
Results 501 - 550 of 1130
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Steppan Jochen - - 2006
Cardiac myocytes contain two constitutive NO synthase (NOS) isoforms with distinct spatial locations, which allows for isoform-specific regulation. One regulatory mechanism for NOS is substrate (l-arginine) bioavailability. We tested the hypothesis that arginase (Arg), which metabolizes l-arginine, constrains NOS activity in the cardiac myocyte in an isoform-specific manner. Arg activity ...
Heilmann Claudia - - 2006
INTRODUCTION: Growth factor therapy provides a therapeutic alternative for "no option" patients with coronary disease. Fibroblast Growth Factor-2 (FGF-2) predominantly stimulates angiogenesis, the growth of new capillaries, whereas Monocyte Chemoattractant Protein-1 (MCP-1) is considered an arteriogenic agent. We hypothesised a synergetic effect of FGF-2 and MCP-1 in ischemic myocardium. METHODS: ...
Loichot Cécile - - 2006
The peroxisome proliferator-activated receptor-alpha (PPARalpha) plays a major role in the control of cardiac energy metabolism. The role of PPARalpha on cardiac functions was evaluated by using PPARalpha knockout (PPARalpha -/-) mice. Hemodynamic parameters by sphygmomanometric measurements show that deletion of PPARalpha did not affect systolic blood pressure and heart ...
Canton Marcella - - 2006
AIMS: We addressed a potential mechanism of myocardial dysfunction following coronary microembolization at the level of myofibrillar proteins. METHODS AND RESULTS: Anaesthetized pigs underwent intracoronary infusion of microspheres. After 6 h, the microembolized areas (MEA) had decreased systolic wall thickening to 38 +/- 7% of baseline and a 2.62 +/- ...
Kharin Sergey N - - 2006
The avian cardiovascular system is of special interest because avian hearts are relatively larger than mammalian hearts, and activation of ventricular myocardium in birds has a "flash" pattern. Systolic time intervals and indices of myocardial contractility were examined in anaesthetized open-chest chickens by polycardiography, including synchronous recordings of electrocardiogram, phonocardiogram, ...
Joshi Mandar S - - 2006
Cyclosporin A (CsA) is known to preserve cardiac contractile function during endotoxemia, but the mechanism is unclear. Increased nitric oxide (NO) production and altered mitochondrial function are implicated as mechanisms contributing to sepsis-induced cardiac dysfunction, and CsA has the capacity to reduce NO production and inhibit mitochondrial dysfunction relating to ...
Linte Cristian A - - 2006
This work presents the first steps towards the development and implementation of a novel 3D biomechanical-based method for assessing the viability of myocardial tissue, with particular interest for its application in myocardial infarction (MI) diagnosis. This assessment technique quantifies the myocardial contraction forces developed within the ventricular myofibrils in response ...
Ren Jun - - 2006
Heart disease is among the leading causes of death in all populations. Cardiac dysfunctions are major complications in patients with advanced viral or bacterial infection, severe trauma and burns accompanied with multiple organ failure - collectively known as systemic inflammatory response syndrome (SIRS). SIRS, which is often subsequent to sepsis, ...
Mitro Peter - - 2006
OBJECTIVE: Increased myocardial contractility and inadequate cardiac filling leading to activation of the Bezold-Jarisch reflex were proposed as possible triggering mechanisms of vasovagal syncope (VVS). In the present study noninvasive hemodynamic measurements were performed in order to examine the role of myocardial contractility and cardiac filling in pathogenesis of VVS. ...
Weber Th - - 2006
OBJECTIVE: Cardiac stunning is the consequence of a brief cardiac ischemia. The underlying mechanism is not completely understood. METHODS: Here we induced cardiac transient ischemia in conscious instrumented dogs by means of an occluder in the left anterior descending coronary artery (LAD). Contractile performance, monitored by ultrasound crystals, was reduced ...
Loyer X - - 2005
Although nitric oxide-dependent regulation of contractile function is altered in the diseased and failing heart, several aspects of nitric oxide (NO) signalling in the myocardium remain poorly understood. Some apparently contrasting findings may have arisen from the use of non-isoform-specific inhibitors of NO synthase isoforms (NOS) as compared to the ...
Petre Rebecca E - - 2005
OBJECTIVE: The goal of this study was to examine in vitro tissue stiffness and contractile performance in myocardial amyloidosis. BACKGROUND: Primary systemic amyloidosis involves the deposition of amyloid protein in mesodermal tissues including the heart. Functional assessment of cardiac amyloidosis is usually performed using echocardiography. However, this technique does not ...
Ren Jun - - 2005
Pro-inflammatory factors such as the adipokine leptin and cytokine tumor necrosis factor-alpha (TNFalpha) have been implicated in the onset of myocardial dysfunction in ischemia-reperfusion injury, sepsis, heart failure, viral myocarditis and cardiac allograft rejection. Although circulating TNFalpha and leptin levels are both elevated under a variety of inflammatory conditions, it ...
Ohshima Satoru - - 2005
OBJECTIVES: We investigated the relationship between iodine-123-metaiodobenzylguanidine (123I-MIBG) findings and myocardial contractile reserve in patients with mild to moderate dilated cardiomyopathy (DCM). BACKGROUND: Little is known regarding the relationship between cardiac sympathetic nervous function and myocardial contractile reserve in DCM. METHODS: Twenty-four DCM patients who showed sinus rhythm underwent echocardiography, ...
Birla Ravi K - - 2005
The ability to engineer cardiac tissue in vitro is limited by the absence of a vasculature. In this study we describe an in vivo model which allows neovascularization of engineered cardiac tissue. Three-dimensional cardiac tissue, termed "cardioids," was engineered in vitro from the spontaneous delamination of a confluent monolayer of ...
Luptak Ivan - - 2005
BACKGROUND: Downregulation of peroxisome proliferator-activated receptor-alpha (PPARalpha) in hypertrophied and failing hearts leads to the reappearance of the fetal metabolic pattern, ie, decreased fatty acid oxidation and increased reliance on carbohydrates. Here, we sought to elucidate the functional significance of this shift in substrate preference. METHODS AND RESULTS: We assessed ...
Osadchii Oleg - - 2005
Using immunoassay measurements, neurotensin was identified in rat ventricular tissue and in coronary effluent samples. Exogenous neurotensin evoked contractile responses in isolated ventricular preparations, which were equivalent in magnitude to those of norepinephrine and histamine, but greater than those for serotonin and angiotensin II. EC(50) values revealed neurotensin to be ...
Cerra Maria Carmela - - 2006
In this study we tested the hypothesis that vasostatins could act as myocardial modulators in the mammalian heart. Using the Langendorff-perfused rat heart, the cardiac effects of the two recombinant human CGA N-terminal fragments STA-CGA1-78 and STA-CGA1-115, containing the vasostatin-1 (CGA 1-76) and vasostatin-2 (CGA 1-113) sequences, respectively, were evaluated ...
Chai Wenxia - - 2005
Aldosterone exerts rapid "nongenomic" effects in various nonrenal tissues. Here, we investigated whether such effects occur in the human heart. Trabeculae and coronary arteries obtained from 57 heart valve donors (25 males; 32 females; 17 to 66 years of age) were mounted in organ baths. Aldosterone decreased contractility in atrial ...
Convertino Victor A - - 2005
INTRODUCTION: Occurrence of serious cardiac dysrhythmias and diminished cardiac and vascular function are the primary cardiovascular risks of spaceflight identified in the 2005 NASA Bioastronautics Critical Path Roadmap. METHODS: A review of the literature was conducted on experimental results and observational data obtained from spaceflight and relevant ground simulation studies ...
Konrad D - - 2005
The endothelin (ET) system is involved in the regulation of myocardial function in health as well as in several diseases, such as congestive heart failure, myocardial infarction, and septic myocardial depression. Conflicting results have been reported regarding the acute contractile properties of ET-1. We therefore investigated the effects of intracoronary ...
Ros María N - - 2005
BACKGROUND: Myocardial stretch promotes an increase in developed force (DF) in two phases: a rapid initial phase, and a slowly developing second phase called the slow force response (SFR) to myocardial stretch. The SFR results from an autocrine/paracrine mechanism of angiotensin II and endothelin (ET) release that is triggered by ...
Martin R Shayn - - 2005
Cardiovascular dysfunction associated with the systemic inflammatory response syndrome (SIRS) is caused by a combination of decreased myocardial contractility and low vascular resistance. The contribution of each of these components can be determined at the bedside, and directed therapy can be appropriately initiated. Over an 8-month period of time, 23 ...
Sharma Sanjiv - - 2005
Myocardial stunning, a reversible decrease in the contractile function of the myocardium after an ischemic insult, often leads to hypotension that requires therapy with intravenous inotropes. We used the oral agent midodrine to treat hypotension that complicated myocardial stunning after successful revascularization with percutaneous coronary intervention in the setting of ...
Janardhanan Rajesh - - 2005
BACKGROUND: Both myocardial contrast echocardiography (MCE) and cardiovascular magnetic resonance (CMR) can identify myocardial necrosis after acute myocardial infarction (AMI). However, transmural extent of infarction (TEI) correlates of myocardial perfusion by MCE after AMI are unknown. We sought to ascertain the ability of MCE to (1) predict TEI as defined ...
Nelson C - - 2005
Not all myocardium involved in a myocardial infarction is dead or irreversibly damaged. The balance between the amount of scar and live tissue, and the nature of the live tissue, determine the likelihood that contractile function will improve after revascularisation. This improvement (which defines viability) may be predicted with about ...
Komuro Kaoru - - 2005
BACKGROUND: Myocardial viability is not synonymous with contractile reserve and identifiable in a significant percentage of dysfunctional myocardial segments without contractile reserve. The usefulness of ultrasonic tissue characterization by the phase-corrected magnitude of cyclic variation of integrated backscatter (MVIB) in chronic coronary artery disease is not fully validated. Thus, whether ...
Martisiene I - - 2005
PURPOSE: The purpose of present study was to investigate the effect of metabolic substrate pyruvate and beta-adrenergic agonist isoproterenol and combination of these agents on the force- and relaxation-frequency relationship in human heart failure. MATERIAL AND METHODS: The experiments were performed on isolated human ventricle strips from patients undergoing cardiac ...
Abdelaziz Ahmed Ihab - - 2005
Most patients with hypertrophic cardiomyopathy and congenital heart diseases express the atrial essential myosin light chains (ALC-1) in their ventricles, replacing the ventricular essential light chains (VLC-1). VLC-1/ALC-1 isoform shift is correlated with increases in cardiac contractile parameters of a transgenic rat model overexpressing hALC-1 in the heart (TGR/hALC-1) compared ...
Suinesiaputra A - - 2005
An important assessment in patients with ischemic heart disease is whether myocardial contractility may improve after treatment. The prediction of myocardial contractility improvement is generally performed under physical or pharmalogical stress conditions. In this paper, we present a technique to build a statistical model of healthy myocardial contraction using independent ...
Kemming G - - 2005
Inhaled prostacyclin (PGI(2)) aerosol induces selective pulmonary vasodilation. Further, it improves right ventricular (RV) function, which may largely rely on pulmonary vasodilation, but also on enhanced myocardial contractility. We investigated the effects of the inhaled PGI(2) analogs epoprostenol (EPO) and iloprost (ILO) on RV function and myocardial contractility in 9 ...
Liakopoulos Oliver J - - 2005
OBJECTIVE: Mild to moderate transient contractile dysfunction is frequently observed after cardiac surgery on cardiopulmonary bypass (CPB) but may also lead to low-cardiac-output (LCO) failure especially in patients with unstable angina, and is often referred to represent myocardial stunning. Whether time course of contractile dysfunction after cardiac surgery is similar ...
Park Kwan Ha - - 2004
To examine the functional effects of cholinergic modulation compounds in oyster hearts and to explore their possible use in monitoring intoxication with acetylcholine-esterase (AChE) inhibitors such as organophosphates, tests were performed with in situ oyster heart preparations. The endogenous cholinergic agonist acetylcholine (ACh), AChE-resistant synthetic agonist carbachol, and the reversible ...
Horton Jureta W - - 2004
Large cutaneous burns are clearly recognized to produce acute myocardial contractile dysfunction. This study used a model of burn serum challenge in either primary cardiomyocyte cultures or isolated perfused hearts to examine several aspects of burn-serum-related contractile dysfunction as well as myocardial inflammatory responses. Despite the absence of detectable LPS ...
Holland Mark R - - 2004
BACKGROUND: In a number of recently published studies comparing measurements from patients with those from control subjects, a decreased magnitude of the systematic variation of backscattered energy over the heart cycle (cyclic variation) is accompanied by an increased level of overall myocardial backscatter (calibrated myocardial image brightness) when measured at ...
Stoica Serban C - - 2004
BACKGROUND: Experimental and clinical studies suggest that brain death (BD)-associated cardiac dysfunction is related to the neurohormonal storm and subsequent exposure to intravenous catecholamines. We aimed to describe the relationship between empirical noradrenaline treatment and donor heart function, described for the first time with load-independent indices of right ventricular contractility. ...
Cazorla Olivier - - 2005
The "stretch-sensitization" response is essential to the regulation of heart contractility. An increase in diastolic volume improves systolic contraction. The cellular mechanisms of this modulation, the Frank-Starling law, are still uncertain. Moreover, their alterations in heart failure remains controversial. Here, using left ventricular skinned rat myocytes, we show a nonuniform ...
Kompa Andrew R - - 2004
Urotensin II (UII) is a potent vaso-active peptide thought to have multiple roles in the regulation of cardiovascular physiology and pathophysiology. The actions of UII are complex and difficult to interpret given its systemic hemodynamic effects and variable action on different vascular beds and isolated vessels. Direct effects of UII ...
Haghighi Kobra - - 2004
Dilated cardiomyopathy is a disease of the heart muscle resulting from a diverse array of conditions that damages the heart and impairs myocardial function. Heart failure occurs when the heart is unable to pump blood at a rate which can accommodate the heart muscle's metabolic requirements. Several signaling pathways have ...
Brattelid Trond - - 2004
Serotonin (5-hydroxytryptamine, 5-HT) increases contractile force and elicits arrhythmias through 5-HT(4) receptors in porcine and human atrium, but its ventricular effects are unknown. We now report functional 5-HT(4) receptors in porcine and human ventricle. 5-HT(4) mRNA levels were determined in porcine and human ventricles and contractility studied in ventricular trabeculae. ...
Szabó Gábor - - 2004
Although hemodynamic instability and cardiac dysfunction after brain death are reported in the potential organ donor, the underlying mechanisms, such as neuro-humoral changes, myocardial injury, and altered loading conditions, are discussed contrarily. The physiologic regulatory mechanisms that may contribute to the reduction of cardiac function after brain death are reviewed. ...
Noguchi Teruo - - 2004
The contribution of the sarcomere's thin filament to the contractile dysfunction of human cardiomyopathy is not well understood. We have developed techniques to isolate and functionally characterize intact (native) thin filaments obtained from failing and nonfailing human ventricular tissue. By use of in vitro motility and force assays, native thin ...
Trukhin A N - - 2004
Histidine (3x10(-5) g/ml) had no effect on contractility and chronoinotropic relationships in frog myocardium, but rapidly and reversibly increased myocardial beta-adrenoreactivity (increased myocardial response to 7x10(-8), 3x10(-7), and 4x10(-6) g/ml epinephrine) and potentiated the positive effect of epinephrine (7x10(-8), 3x10(-7) g/ml) on chronoinotropic relationships in the myocardium. Histidine is considered ...
Tuzcu E Murat - - 2004
Stroke is a leading cause of death and disability in the United States. Cryptogenic stroke may account for up to 40% of strokes, and it is commonly associated with patent foramen ovale. Ischemic strokes often are associated with atrial fibrillation and left atrial appendage. Devices have been developed to reduce ...
Chockalingam Nachiappan - - 2004
Although the causes and progression of adolescent idiopathic scoliosis (AIS) are still unclear, a recent extensive review has indicated a number of possible aetiological factors. Previous investigations, employing gait measurements, have indicated asymmetries in the ground reaction forces and suggest a relationship between these asymmetries, neurological dysfunction and spinal deformity. ...
Asahi Michio - - 2004
Sarcolipin (SLN) inhibits the cardiac sarco(endo)plasmic reticulum Ca(2+) ATPase (SERCA2a) by direct binding and is superinhibitory if it binds through phospholamban (PLN). To determine whether overexpression of SLN in the heart might impair cardiac function, transgenic (TG) mice were generated with cardiac-specific overexpression of NF-SLN (SLN tagged at its N ...
Kennedy Richard H - - 2004
Previous studies have shown that chronic hyperhomocysteinemia is associated with an adverse cardiac remodeling and heart failure. This study, which utilized coronary-perfused hearts and superfused papillary muscle, was designed to determine whether homocysteine acts acutely to alter cardiac contractile function. Left ventricular developed pressure was used as a measure of ...
Suga Hiroyuki - - 2004
The efficiency from the ventricular O(2) consumption (VO(2)) to the total mechanical energy (TME) generated by ventricular contraction has proved relatively constant at approximately 35%, independent of the loading and contractile conditions in a canine heart. TME is the sum of the external mechanical work for ejecting a stroke volume ...
Jiménez Rosa M RM Servicio de Cardiología, Hospital Universitario de Salamanca, Salamanca, - - 2004
We report a woman with a VVI pacemaker and a history of stroke and severe hypoxemia due to a right-to-left shunt. Anomalous blood flow was through a patent foramen ovale, and was related directly with severe tricuspid regurgitation because the ventricular pacemaker electrode was adhered to the tricuspid valve. She ...
Walker Ernest - - 2004
Male Sprague-Dawley rats were subjected for 2 weeks to daily injections of homocysteine (Hcy), which increased plasma Hcy approximately 2-fold. Echocardiography indicated significant increases in left ventricular diastolic (13%) and systolic (31%) dimensions and decreases in posterior wall thickness (diastolic, -17%; systolic, -20%) in Hcy-treated animals. Slight changes were noted ...
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