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Results 501 - 550 of 1146
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Hambleton, Michael
Heart failure is the leading cause of death in the western world and continues to represent an enormous clinical challenge despite significant improvements using pharmacological therapies. Recent evidence suggests that enhancing cardiac contractility is of potential benefit for the treatment of heart failure. The loss of contractility that accompanies heart ...
Rivera Jaime - - 2007
OBJECTIVE: To report the development of myocardial stunning and severe heart failure after lightning strike with total recovery of function. DESIGN: Case report. SETTING: Coronary care unit at Medica Sur Clinic, Mexico. PATIENT: A 42-yr-old woman who was hit by lightning developed rapid and progressive hemodynamic deterioration manifested by cardiogenic ...
Pitts Kelly R - - 2007
In vitro experimental models designed to study the effects of hypoxia and ischemia typically employ oxygen-depleted media and/or hypoxic chambers. These approaches, however, allow for metabolites to diffuse away into a large volume and may not replicate the local buildup of metabolic byproducts that occur in ischemic myocardium in vivo. ...
Narolska, N.A.
The main objective of this thesis was to elucidate the effect of translational and post-translational alterations in contractile proteins occurring during heart failure on contractile function in human cardiac tissue. Isometric force and ATPase activity measurements were performed in skinned human cardiac trabeculae and muscle strips; force was measured in ...
Pleger S T - - 2006
S100A1, a Ca superset2+-binding protein of the EF-hand type, is preferentially expressed in myocardial tissue and has been shown to enhance cardiac contractile performance by regulating both sarcoplasmic reticulum (SR) Ca superset2+-handling and myofibrillar Ca superset2+-responsiveness. In cardiac disease, the expression of S100A1 is dynamically altered as it is significantly ...
Figueras Jaume - - 2006
BACKGROUND: It is unclear whether spontaneous improvement in contractility following acute myocardial infarction (AMI) is related to severity of predischarge systolic dysfunction and can be predicted by isotopic ventriculography with a low-dose dobutamine test (DBT). HYPOTHESIS: Spontaneous improvement in contractility would be similar in patients with more preserved and those ...
Schmidt-Ott Ursula Maria - - 2006
Thyroid hormone metabolic disarray has been identified as a risk factor for the progression of heart disease and the development of heart failure (HF). Both hyper- and hypothyroidism have been associated with a failing myocardium. Poor cardiac contractility and low cardiac output due to hyperthyroidism is a rare occurrence and ...
Machackova Jarmila - - 2006
BACKGROUND: A wide variety of pathological conditions have been shown to result in cardiac remodelling and myocardial dysfunction. However, the mechanisms of transition from adaptive to maladaptive alterations, as well as those for changes in cardiac performance leading to heart failure, are poorly understood. OBSERVATIONS: Extensive studies have revealed a ...
Yamada Satoshi - - 2006
PURPOSE OF REVIEW: Ultrasonic tissue characterization is a non-invasive diagnostic method that uses myocardial integrated backscatter analysis to determine contractile performance and myocardial viability independent of wall motion. This review discusses recent clinical findings regarding the application of ultrasonic tissue characterization for the assessment of myocardial viability. RECENT FINDINGS: As ...
Koi P T - - 2007
The molecular interaction between smooth muscle (SM) myosin and actin in the corpus cavernosum (CC) determines the erectile state of the penis. A key mechanism regulating this interaction and subsequent development and maintenance of force is alternative splicing of SM myosin heavy chain (MHC) and 17 kDa essential SM myosin ...
Nerurkar Nandan L - - 2006
The biophysical mechanisms that drive and regulate cardiac looping are not well understood, but mechanical forces likely play a central role. Previous studies have shown that cardiac torsion, which defines left-right directionality, is caused largely by forces exerted on the heart tube by a membrane called the splanchnopleure (SPL). Here ...
Hussain Monira B - - 2006
BACKGROUND: Angiotensin II is a powerful vasoconstrictor and regulator of cardiovascular growth. Also, it increases formation of reactive oxygen species and contributes to vascular dysfunction. We investigated the role of oxidant stress in contraction of human resistance arteries to angiotensin II, in health and in the presence of cardiovascular disease. ...
Szabó Gábor - - 2006
Recent studies suggested that the peroxynitrite-poly (ADP-ribose) polymerase (PARP) pathway is activated during acute allograft rejection. We investigated whether PARP inhibition improves transplant function during cardiac rejection. Isogeneic Lewis-to-Lewis and allogeneic Dark Agouti-to-Lewis rat cardiac transplants were studied under treatment with placebo or with the PARP-inhibitor INO-1001 (1 mk/kg/day), Functional, ...
Rémond Mathieu C - - 2006
During the initial phase of cardiac looping, known as c-looping, the heart bends and twists into a c-shaped tube with the convex outer curvature normally directed toward the right side of the embryo. Despite intensive study for more than 80 years, the biophysical mechanisms that drive and regulate looping remain ...
Xiong Ye - - 2006
The cardiac toxicity of doxorubicin (DOX), a potent anticancer anthracycline antibiotic, is believed to be mediated through the generation of reactive oxygen species (ROS) in cardiomyocytes. This study aims to determine the function of cellular glutathione peroxidase (Gpx1), which is located in both mitochondria and cytosol, in defense against DOX-induced ...
Zimmermann Wolfram-Hubertus - - 2006
The concept of regenerating diseased myocardium by implantation of tissue-engineered heart muscle is intriguing, but convincing evidence is lacking that heart tissues can be generated at a size and with contractile properties that would lend considerable support to failing hearts. Here we created large (thickness/diameter, 1-4 mm/15 mm), force-generating engineered ...
Pott C - - 2006
Next to beta1- and beta2-adrenoceptors, a third beta-adrenoceptor population is expressed in the human heart, the beta3-adrenoceptor. In mammalian ventricular myocytes, beta3-adrenergic stimulation leads to a decrease in contractility via a release of nitric oxide (NO). Recently, different molecular mechanisms of beta3-adrenergic activation of endothelial nitric oxide synthase (eNOS) have ...
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 ...
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. ...
Linte Cristian A CA Biomed. Eng., Univ. of Western Ontario, London, ON, - - 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 ...
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 ...
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