Search Results
Results 451 - 500 of 1126
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Sando Ian C - - 2008
Tumor necrosis factor-alpha (TNF-alpha) plays a critical role in myocardial dysfunction following acute injury. It is unknown, however, if a gender-specific response to TNF infusion exists in isolated rat hearts. Elucidating such mechanisms is important to understanding the myocardial gender differences during acute injury. We hypothesize that females will exhibit ...
Lian F - - 2008
This study was designed to evaluate the long-term effect of endothelial progenitor cell (EPC) implantation in acute myocardial infarction in Sprague-Dawley rats after ligation of the left anterior descending coronary artery. Autologous EPCs from peripheral blood were purified and implanted into an acute myocardial infarct site. Specimens and muscle strip ...
Lee Marlon A - - 2008
Acute injury-induced cardiac contractile dysfunction occurs even in young and otherwise healthy individuals after major injuries, and significantly contributes to morbidity and mortality in patients with pre-existent cardiac diseases as well as in patients who develop multiple organ dysfunction syndrome. Recent studies indicate that post-injury acute cardiac failure is the ...
Moniotte S - - 2007
To analyze the implication of the beta3-adrenoceptor (beta3-AR) pathway in human septic myocardium and a murine model of sepsis, a condition associated with myocardial depression. beta3-AR and eNOS protein abundance were increased (332+/-66.4% and 218+/-39.3; P<0.05) in hearts from septic patients. The effect of BRL37344, a beta3-AR-preferential agonist, was analyzed ...
Ghanem Alexander - - 2008
Myocardial remodeling determines the degree of left ventricular dysfunction and mortality after transmural chronic myocardial infarction (CMI). Noninvasive characterization and quantitation of myocardial borderzone and collagenous scar are therefore parameters of clinical interest. The aims of this study were (i) to measure accuracy of reconstructive 3-D echocardiography (3DE) in scar ...
Smith Godfrey - - 2007
Heart failure as a result of a myocardial infarction (MI) is a common condition with a poor prognosis. The adaptive changes in the surviving myocardium appear to be insufficient in terms of both mechanical/contractile performance and electrical stability. The modification of the underlying myocardial physiology is complex, varying across the ...
Huang Q-Q - - 2008
In contrast to skeletal muscles that simultaneously express multiple troponin T (TnT) isoforms, normal adult human cardiac muscle contains a single isoform of cardiac TnT. To understand the significance of myocardial TnT homogeneity, we examined the effect of TnT heterogeneity on heart function. Transgenic mouse hearts overexpressing a fast skeletal ...
Hambleton Michael - - 2007
Mice null for the gene encoding protein kinase Calpha (Prkca), or mice treated with pharmacologic inhibitors of the PKCalpha/beta/gamma isoforms, show an augmentation in cardiac contractility that appears to be cardioprotective. However, it remains uncertain if PKCalpha itself functions in a myocyte autonomous manner to affect cardioprotection in vivo. Here ...
Guarracino F - - 2007
BACKGROUND: Levosimendan, a novel calcium sensitizer, enhances myocardial contractility without affecting intracellular calcium concentration. It also dilates peripheral arterial vessels by acting on ATP-dependent K(+) channels. Ventriculo-arterial coupling, the relationship between myocardial contractility and the arterial system, describes the efficiency of the cardiovascular system by analysing the relationship between myocardial ...
Smith Godfrey L - - 2007
Heart failure as a result of a myocardial infarction (MI) is a common condition with a poor prognosis. The adaptive changes in the surviving myocardium appear to be insufficient in terms of both mechanical/contractile performance and electrical stability. The modification of the underlying myocardial physiology is complex, varying across the ...
Quaile Michael P - - 2007
Myocardial contractile reserve is significantly attenuated in patients with advanced heart failure. The aim of this study was to identify mechanisms of impaired contractile reserve in a large animal model that closely mimics human myocardial failure. Progressive right ventricular hypertrophy and failure were induced by banding the pulmonary artery in ...
Stehr Sebastian N - - 2007
BACKGROUND: Levosimendan is a novel drug used for inotropic support in heart failure, but its efficacy in local anesthetic-induced myocardial depression is not known. Therefore, we investigated the effects of levosimendan on the negative inotropic response to ropivacaine in isolated heart preparations of guinea pigs. METHODS: Action potentials and force ...
Rastaldo R - - 2007
Nitric oxide (NO) participates in the control of contractility and heart rate, limits cardiac remodeling after an infarction and contributes to the protective effect of ischemic pre- and postconditioning. Low concentrations of NO, with production of small amounts of cGMP, inhibit phosphodiesterase III, thus preventing the hydrolysis of cAMP. The ...
Ohta Soichiro - - 2007
BACKGROUND: Increased nitric oxide (NO) in the failing heart attenuates the myocardial contractile response to beta-adrenergic receptor stimulation. However, the physiological effects of NO on the beta-adrenergic post-receptor signaling system are unknown. The objective of the present study was to examine the effects of cardiac NO synthase (NOS) inhibition on ...
Carceles Mafía D - - 2007
BACKGROUND: Because milrinone is a widely used phosphodiesterase-3 (PDE3) inhibitor, it would be of interest to know whether it interacts with beta1- and beta2-adrenergic receptor (AR) agonists in human myocardium. OBJECTIVES: This in vitro study was conducted to test whether milrinone differentially regulates cyclic adenosine-3',5'-monophosphate (cAMP) production and to examine ...
Gupta Mahesh P - - 2007
Myosin is a molecular motor, which interacts with actin to convert the energy from ATP hydrolysis into mechanical work. In cardiac myocytes, two myosin isoforms are expressed and their relative distribution changes in different developmental and pathophysiologic conditions of the heart. It has been realized for a long time that ...
Peisker T - - 2007
A 22-year-old woman developed an anaphylactic reaction after two hornet stings. Left-sided hemiparesis and gaze paresis were revealed after extubation 24 hours later. The vasoconstriction of the right MCA together with hypotension are the suggested pathogenetic determinants of the stroke.
Huschak G - - 2007
Chronic heart failure is known to be an important risk factor for adverse perioperative outcome in patients undergoing non-cardiac surgery. A promising new form of electric therapy is currently being used in a phase III trial in patients with severe chronic heart failure (cardiac contractility modulation). Cardiac contractility modulation is ...
Markert Michael - - 2007
INTRODUCTION: The objective of this study was to define the normal LVdP/dt (an index of myocardial contractility)-heart rate relationship in telemetered conscious dogs, primates and mini-pigs in our laboratory and to use these data as the basis for an additional parameter useful in drug safety evaluation. METHODS: Trained dogs, Rhesus ...
KODAMA, Makoto
Inotropic and lusitropic reserves of failing hearts were investigated using a stepwise intravenous dobutamine loading test in patients with chronic heart failure. The forty-one patients enrolled in this study were classified into 4 groups according to the left ventricular end-systolic volume indices (LVESVI). The left ventricular size of Group 1 ...
Epstein Frederick H - - 2007
Transgenic and knockout mice can be used to study the genes and basic mechanisms involved in heart disease, and have therefore assumed a central role in modern cardiac research. MRI and MRS techniques have recently been developed for mice that enable the quantitative or semi-quantitative in vivo assessment of cardiac ...
Aagaard S - - 2007
BACKGROUND: In a porcine model, the cardioprotective effect of sevoflurane was studied with regard to the preservation of myocardial contractility (myocardial stunning) after a myocardial ischaemic insult. METHODS: Twenty-seven pigs were randomized to receive either a dual 4% sevoflurane inhalation period as a supplement to pentobarbital anaesthesia or pentobarbital anaesthesia ...
Moreira-Rodrigues M - - 2007
There is an increased incidence of heart disease in patients with chronic nephrotic syndrome (NS), which may be attributable to the malnutrition and activated inflammatory state accompanying the sustained proteinuria. In this study, we evaluated renal function, cardiac morphometry, contractile function, and myocardial gene expression in the established puromycin aminonucleoside ...
Carlson Deborah L - - 2007
In the heart, thermal injury activates a group of intracellular cysteine proteases known as caspases, which have been suggested to contribute to myocyte inflammation and dyshomeostasis. In this study, Sprague-Dawley rats were given either a third-degree burn over 40% total body surface area plus conventional fluid resuscitation or sham burn ...
Nef Holger M - - 2007
AIMS: To gain more insight into the phenomenon of Tako-Tsubo cardiomyopathy (TTC), the purpose of the present study was to investigate the myocardial structure in the acute phase of TTC and after functional recovery. METHODS AND RESULTS: We studied eight patients presenting with TTC diagnosed by coronary angiography, ventriculography, magnetic ...
Missant Carlo - - 2007
OBJECTIVE: Experimental data suggest that levosimendan has pulmonary vasodilatory properties which, in combination with its positive inotropic effects, would render it particularly attractive for the treatment of right ventricular dysfunction. To test this hypothesis, we developed an experimental model of right ventricular failure and analyzed the effects of levosimendan on ...
Wappler Frank - - 2007
BACKGROUND: Volatile anesthetics are commonly used for general anesthesia. However, these can induce profound cardiovascular alterations. Xenon is a noble gas with potent anesthetic and analgesic properties. However, it is uncertain whether xenon alters myocardial function. The aim of this study was therefore to investigate left ventricular function during anesthesia ...
Schulze Karsten - - 2007
Mechanisms of adenosine (ADO) protection of reperfused myocardium are not fully understood. We tested the hypothesis that ADO (0.1 mM) alleviates ventricular stunning by ADO A(1)-receptor stimulation combined with purine metabolic enhancements. Langendorff guinea pig hearts were stunned at constant left ventricular end-diastolic pressure by low-flow ischemia. Myocardial phosphate metabolites ...
Yuan Qunying - - 2007
BACKGROUND: Abnormal sarcoplasmic reticulum calcium (Ca) cycling is increasingly recognized as an important mechanism for increased ventricular automaticity that leads to lethal ventricular arrhythmias. Previous studies have linked lethal familial arrhythmogenic disorders to mutations in the ryanodine receptor and calsequestrin genes, which interact with junctin and triadin to form a ...
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 +/- ...
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