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Results 451 - 500 of 2809
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Hicks Juan J - - 2007
In myocardial infarctions with ST-segment elevation, ischemia followed by reperfusion (IR) leads to arrhythmia, myocardial stunning and endothelial dysfunction injury by reactive oxygen species (ROS). To determine the impact of ROS, we examined the effect of antioxidant vitamins on biochemical changes and arrhythmias induced by reperfusion before and after therapeutic ...
Selimoglu Ozer - - 2007
BACKGROUND: The prevention of perioperative ischemia-reperfusion injury is of critical importance, and this issue becomes more important in patients undergoing an early emergent revascularization procedure after an acute myocardial infarction. In this study, we sought to test the hypothesis that our simplified pressure-controlled initial reperfusion technique would be protective against ...
Otake Hiromasa - - 2007
OBJECTIVES: This study evaluated the efficacy of catheter-based transcoronary myocardial hypothermia (CTMH) in pigs with acute myocardial ischemia. BACKGROUND: Although it has been suggested that hypothermia therapy can attenuate myocardial necrosis, few applications have been accepted for clinical use. METHODS: This study comprises 2 substudies. In both studies, pigs underwent ...
Schmidt M R - - 2007
Remote ischemic preconditioning reduces myocardial infarction (MI) in animal models. We tested the hypothesis that the systemic protection thus induced is effective when ischemic preconditioning is administered during ischemia (PerC) and before reperfusion and examined the role of the K(+)-dependent ATP (K(ATP)) channel. Twenty 20-kg pigs were randomized (10 in ...
Gale Stephen C - - 2007
BACKGROUND: In cardiopulmonary bypass, extracorporeal circulation activates neutrophils, which contribute to ischemia reperfusion injury and postoperative myocardial dysfunction. Perfluorocarbons (PFCs) are compounds that dissolve oxygen and have anti-inflammatory and neutrophil-stabilizing properties. We hypothesized that perflubron emulsion (PFE), a PFC, would attenuate neutrophil activation during simulated extracorporeal circulation (SECC) and would ...
Lu Chuanjiang - - 2006
BACKGROUND: Nicorandil has been reported to induce cardioprotection by opening the mitochondrial K(ATP) channels. However, whether nicorandil affects reactive oxygen species is unclear. METHODS AND RESULTS: The hearts of male Sprague-Dawley rats were excised and perfused on a Langendorff apparatus with Krebs-Henseleit solution with a gas mixture of 95% O(2) ...
Hale Sharon L - - 2006
Ranolazine is a selective inhibitor of the late sodium current relative to peak sodium channel current, and via this mechanism, it may decrease sodium-dependent intracellular calcium overload during ischemia and reperfusion. Ranolazine reduces the frequency of angina attacks, but there is little information on its effects on myocardial stunning after ...
Besse S - - 2006
Cardiovascular ageing is associated with an increase in cardiac susceptibility to ischaemia and reperfusion and production of reactive oxygen species has been suspected to be responsible for this age-associated particular vulnerability. To determine whether administration of antioxidant treatment could afford some protection against ischaemia and reperfusion during aging, isolated perfused ...
Penumathsa Suresh Varma - - 2007
Therapeutic angiogenesis represents a novel approach for the prevention and treatment of ischemic heart disease. This study examined a novel method of stimulating myocardial angiogenesis using secoisolariciresinol diglucoside (SDG), a plant lignan isolated from flaxseed. SDG has been shown to decrease serum cholesterol and reduce the extent of atherosclerosis. In ...
Manintveld Olivier C - - 2007
Postconditioning (POC) is known as the phenomenon whereby brief intermittent ischemia applied at the onset of reperfusion following index ischemia limits myocardial infarct size. Whereas there is evidence that the algorithm of the POC stimulus is an important determinant of the protective efficacy, the importance of the duration of index ...
Laguens Rubén P - - 2007
We have recently reported that in chronic myocardial ischemia, adult mammalian cardiomyocytes express P-glycoprotein (P-gp). We now investigate if P-gp is also expressed in acute regional ischemia followed by reperfusion. Adult conscious sheep underwent 12-min occlusion of the mid-left anterior descending artery (inflatable cuff). Successful ischemia-reperfusion was confirmed by monitoring ...
Jormalainen M - - 2007
BACKGROUND: Antithrombin (AT) may alleviate many cardiopulmonary bypass (CPB) and ischemia-reperfusion (I/R)-related adverse effects. Using a porcine model of clinical cardiac surgery on CPB, we tested the effects of supplementary AT on myocardial and lung I/R injury. METHODS: Twenty pigs undergoing 60-min aortic clamping and 75-min normothermic perfusion were randomized ...
Støttrup Nicolaj B - - 2006
1. L-Glutamate and glutamine have been suggested to have cardioprotective effects. However, the issue is controversial and the metabolic mechanisms underlying a beneficial effect are not well understood. 2. In the present study we investigated the effects of L-glutamate and glutamine on haemodynamic recovery, the rate of de novo glycogen ...
Metzsch C - - 2007
BACKGROUND: Inotropic and myocardial anti-ischemic effects have been demonstrated with levosimendan. The comparison of levosimendan started before an ischemia-reperfusion event as compared with levosimendan started during ischemia has not been studied. METHODS: In anesthetized pigs, a major branch of the circumflex artery was completely occluded for 30 min and then ...
Onogi Hirohito - - 2006
1. In the present study, we investigated the effect of 3-methyl-1-phenyl-2-pyrazolin-5-one (edaravone), a free radical scavenger, on myocardial infarct (MI) size and cardiac function in an in vivo model of MI in rabbits. We further investigated the contribution of hydroxyl radicals, superoxide and nitric oxide (NO) to its effects. 2. ...
Richardt Doreen - - 2006
During myocardial ischemia, a substantial accumulation of norepinephrine occurs in the ischemic zone due to a local nonexocytotic release of norepinephrine. Norepinephrine release is driven by the neuronal monoamine transporter (NET), which reverses its usual transmembrane transport direction. We investigated whether this local accumulation of norepinephrine contributes to irreversible myocardial ...
Jollis James G - - 2006
Despite the accumulation of almost 2 decades of data in support of rapid reperfusion therapy for ST-segment elevation myocardial infarction (STEMI), the United States healthcare system still faces serious challenges in providing reperfusion to all eligible patients in a timely fashion. American College of Cardiology/American Heart Association guidelines call for ...
Yang Zequan - - 2006
BACKGROUND: We previously used adenosine A2A receptor (A2AR) knockout (KO) mice and bone marrow transplantation to show that the infarct-sparing effect of A2AR activation at reperfusion is primarily due to effects on bone marrow-derived cells. In this study we show that CD4+ but not CD8+ T lymphocytes contribute to myocardial ...
Zhao Jing-Lin - - 2007
BACKGROUND: Postconditioning with multiple very short coronary occlusions immediately after prolonged ischemia has been found to reduce infarction size. However, it remains unknown whether postconditioning under the normal or hypercholesterolemic condition can also reduce myocardial no-reflow for which endothelial dysfunction is an important mechanism. METHODS: Twenty-four normal mini-swines were randomized ...
Lanoye Lieve - - 2007
Although reperfusion after coronary occlusion is mandatory for myocardial salvage, reperfusion may trigger a cascade of harmful events (reperfusion injury) adding to myocardial injury. We investigated effects of reperfusion on left ventricular (LV) haemodynamics and ventriculo-arterial (VA) coupling in pigs following acute myocardial ischaemia induced by coronary artery occlusion. Experiments ...
Corcoran T B - - 2006
BACKGROUND: Coronary artery bypass grafting (CABG) with cardiopulmonary bypass elicits a potent reperfusion injury and inflammatory response, more intense in patients with impaired myocardial function. Propofol has antioxidant properties which may attenuate such a response. METHODS: In total, 27 patients with impaired left ventricular function undergoing CABG were randomly allocated ...
García-Rivas G de J Gde - - 2006
The mitochondrial permeability transition pore (mPTP), an energy-dissipating channel activated by calcium, contributes to reperfusion damage by depolarizing the mitochondrial inner membrane potential. As mitochondrial Ca(2+) overload is a main inductor of mPTP opening, we examined the effect of Ru(360), a selective inhibitor of the mitochondrial calcium uptake system against ...
Stoner Jason D - - 2007
Reperfusion of the ischemic myocardium leads to a burst of reactive O(2) species (ROS), which is a primary determinant of postischemic myocardial dysfunction. We tested the hypothesis that early O(2) delivery and the cellular redox state modulate the initial myocardial ROS production at reperfusion. Isolated buffer-perfused rat hearts were loaded ...
Ramu Eyal - - 2006
INTRODUCTION: Dexrazoxane (Dex), used clinically to protect against anthracycline-induced cardiotoxicity, possesses iron-chelating properties. The present study was designed to examine whether Dex could inhibit the ischemia/reperfusion (I/R) induced damage to the rat heart. MATERIALS AND METHODS: Isolated perfused rat hearts were exposed to global ischemia (37 degrees C) and 60 ...
Busk Martin - - 2006
INTRODUCTION: Levosimendan is a positive inotropic drug with vasodilator action and proposed myocardioprotective properties. In a canine model, levosimendan increased coronary collateral flow and reduced myocardial infarct size (IS). We investigated the effect of levosimendan on IS and hemodynamics in the closed-chest porcine ischemia-reperfusion model, which is devoid of coronary ...
Wang Yi - - 2006
PURPOSE: To investigate delayed hyperenhancement during different healing stages of myocardial infarct with and without reperfusion in a pig model. MATERIALS AND METHODS: Twelve pigs were studied. Six pigs were subjected to permanent right coronary artery (RCA) occlusion, and the other six were subjected to transient 90-minute RCA occlusion. In ...
Lessa Marcos A - - 2006
BACKGROUND: We investigated the involvement of central and peripheral opioid receptors (OR) in the cardioprotective effects of fentanyl (FENT) in a model of myocardial ischemia/reperfusion injury associated with pharmacologically induced sympathetic overactivity in anesthetized rabbits. METHODS: Central sympathetic stimulation was achieved through intracerebroventricular injection of l-glutamate in animals submitted to ...
Use Tadasuke - - 2006
PURPOSE: We assessed the dose or timing effect of milrinone administered against myocardial stunning in 37 anesthetized open-chest swine. METHODS: All swine were subjected to 12-min ischemia followed by reperfusion to produce myocardial stunning. Group A (n = 12) received saline in place of milrinone both before and after ischemia. ...
Mykytenko James - - 2007
Cardioprotection with postconditioning has been well demonstrated after a short period of reperfusion. This study tested the hypothesis that postconditioning reduces infarct size, vascular dysfunction, and neutrophil accumulation after a long-term reperfusion. Canines undergoing 60 min left anterior descending artery (LAD) occlusion were divided into two control groups of either ...
Riou L M - - 2007
PURPOSE: Incomplete microvascular reperfusion is often observed in patients undergoing thrombolytic therapy or angioplasty for acute myocardial infarction and has important prognostic implications. We compared the myocardial uptake of diffusible ((201)Tl) and deposited ((99m)TcN-NOET) perfusion imaging agents in the setting of experimental infarction. METHODS: Rats were subjected to permanent coronary ...
Xu Deyi - - 2007
This study was designed to assess the cardioprotective effect of isosteviol on rats with heart ischemia-reperfusion (IR) injury and to explore the mechanism of action of the compound. Sprague Dawley rats were divided into 8 groups (n=10-12): a sham-operated control and 7 ischemia-reperfusion groups (IR control, 3 isosteviol pre-treated (0.5, ...
Koletsis Efstratios - - 2006
Experimental models for studying transplantation have up to now been unable to isolate reperfusion injury with minimal surgical manipulation and without the interference of graft rejection. Six pigs were subjected to left hilum preparation only (control group), and eight pigs were subjected to left hilum preparation plus in situ cooling ...
Ito Hiroshi - - 2006
The rapid restoration of coronary flow to the jeopardized myocardium has become an essential part of therapy after acute myocardial infarction. Despite an open infarct-related artery, breakdown of or obstruction to coronary microvasculature can markedly reduce blood flow to the infarct zone. This effect is known as the no-reflow phenomenon. ...
Ilebekk Arnfinn - - 2006
Neuropeptide Y is released together with norepinephrine from sympathetic nerve terminals during conditions of increased sympathetic activity. Neuropeptide Y is known to inhibit vagal activity, and accordingly, it might increase the risk for ventricular fibrillation during myocardial ischemia-reperfusion, with concomitant sympathetic stimulation. Counteracting the inhibiting effect of neuropeptide Y by ...
Hanzel George S - - 2006
BACKGROUND: Previous reports suggest that elderly patients with acute right ventricular infarction suffer in-hospital mortality of 50% and that hemodynamic compromise is irreversible. We hypothesized that mechanical reperfusion would improve such outcomes. METHODS: We retrospectively analyzed in-hospital morbidity and mortality in 54 patients >70 years of age with acute inferior ...
Dvorak Lubos - - 2006
OBJECTIVE: Leukocyte-mediated reperfusion injury to cardiac allograft in the perioperative period is most likely associated with the early and late mortality after heart transplantation (Htx). Our aim is to determine the efficacy and safety of using leukocyte-depleting filters in a cardiopulmonary bypass (CPB) and secondary blood cardioplegia (SBC) circuit in ...
Reffelmann Thorsten - - 2006
Both animal models of experimental myocardial infarction and clinical studies on reperfusion therapy for acute myocardial infarction have provided evidence of impaired tissue perfusion at the microvascular level after initiation of reperfusion despite adequate restoration of epicardial vessel patency. Characteristics of this "no-reflow" phenomenon found in basic science investigations, such ...
Zhao J-L - - 2006
Simvastatin, a cholesterol-lowering agent, can protect against endothelial dysfunction. However, the effects of simvastatin treatment on the restoration of blood flow to ischemic myocardium are not known. This study sought to assess such effects of simvastatin on an experimental model of myocardial no-reflow and to explore possible mechanisms. Coronary ligation ...
Adameová A - - 2007
Both, diabetes mellitus (DM) and hypercholesterolemia (HCH) are known as risk factors of ischemic heart disease, however, the effects of experimental DM, as well as of HCH alone, on ischemia/reperfusion-induced myocardial injury are not unequivocal. We have previously demonstrated an enhanced resistance to ischemia-induced arrhythmias in rat hearts in the ...
Heusch G - - 2006
The detrimental actions of leptin on cardiovascular function are well established. Smith et al. report the novel finding of a reduction of infarct size by exogenous leptin when given at reperfusion. The involvement of the reperfusion injury salvage kinase (RISK) pathway in such reduction of infarct size and its relation ...
Yu Sung Wook - - 2007
The role of angiogenesis after stroke is unclear; if angiogenesis supports long-term recovery of blood flow, then microvessel hyperdensity consequent to angiogenesis should persist in infarcted cortex. Here, we assess the long-term stability of ischemia-induced microvessels after 2-h transient rat middle cerebral artery occlusion (tMCAo) followed by 30, 90, or ...
Setoyama Kentaro - - 2006
We investigated the effect of olprinone on canine myocardial pump function and myocardial damage after ischemia-reperfusion injury. Three dogs of the experimental group were given olprinone (Olprinone group) and another 3 dogs were served as control (Intact group). All animals were occluded left anterior descending artery for 60 min, followed ...
Zhao Jing-lin - - 2006
BACKGROUND: Both fosinopril and valsartan are effective in protecting endothelial function. We hypothesized that they may also reduce myocardial no-reflow. In addition, suppression of adenosine triphosphate-sensitive K (KATP) channel opening is an important mechanism for myocardial no-reflow. Therefore, this study sought to assess the effect of fosinopril and valsartan on ...
Netuka Ivan - - 2006
1. The number of adult patients undergoing surgery for congenital cyanotic defects in childhood has increased significantly. Therefore, the aim of the present study was to examine the effect of perinatal hypoxia on the tolerance of the adult myocardium to acute ischaemia-reperfusion injury. 2. Pregnant Wistar rats were exposed to ...
Zhang Xue-Juan XJ Department of Cardiology, Affiliated Hospital of Qingdao Medical University, Qingdao 266003, Shandong Province, China. - - 2006
To investigate the effect of shenfu injection on gastrointestinal microcirculation after myocardial ischemic-reperfusion (IR) injury in rabbits and probe into the mechanism. Forty healthy flap-eared white rabbits were randomly divided into 4 groups: IR injury control group (group I), shenfu injection 5 mL/kg per h group (group II), shenfu injection ...
Sesti C - - 2007
The aim of this study was to determine, in an animal model, the effects of tadalafil on myocardial infarct size (IS), hemodynamics and regional myocardial blood flow after myocardial ischemia and reperfusion. Patients with erectile dysfunction (ED) often have risk factors for coronary artery disease. Tadalafil, a long-acting inhibitor of ...
Hamid Shabaz A - - 2006
Exogenous administration or transfection of adrenomedullin (AM) affords protection against ischaemia-reperfusion injury. Here we have examined the role of endogenous AM in regulating the development of myocardial infarction. Wild type (WT) and AM(+/-) mice underwent 30 min regional myocardial ischaemia and 120 min reperfusion. In AM(+/-) hearts, tetrazolium-determined infarct size ...
Yang Yue-Jin - - 2007
Simvastatin can prevent cardiac remodelling after myocardial infarction, though the exact mechanisms are uncertain. Myocardial no-reflow is associated with progressive cardiac remodelling. However, it remains unknown whether post-infarction treatment with simvastatin can also reduce myocardial no-reflow for which suppression of adenosine triphosphate-sensitive K+ (K(ATP)) channel opening is an important mechanism. ...
Iliodromitis Efstathios K - - 2006
Post-conditioning in the early reperfusion period confers protection to the heart after a potentially lethal episode of prolonged ischemia. Protection from this novel intervention has been documented in rat, rabbit and canine hearts, but one group has reported that it is ineffective in pigs, a large-animal species that should be ...
Uchino Kazuaki - - 2006
This study was conducted to clarify the relationship between myocardial endogenous adenosine concentration in the great cardiac vein during ischemia and reperfusion-induced ventricular fibrillation (VF) and the occurrence rate of ischemia and reperfusion-induced VF. Sixty anesthetized mongrel dogs were subjected to 10-min left anterior descending artery occlusion and reperfusion. Blood ...
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