Search Results
Results 401 - 450 of 722
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Stoddard M F - - 1996
OBJECTIVES: This study sought to determine whether calcium antagonist, compared with nitroglycerin, administration attenuates left ventricular dysfunction after exercise-induced ischemia in humans. BACKGROUND: Exercise-induced ischemia impairs left ventricular systolic function and diastolic filling after exercise. The mechanism of this phenomenon is unknown but may relate to intracellular calcium overload. METHODS: ...
Stevens D M - - 1996
Although hyperbaric oxygen has been shown to improve the survival rate of ischemic grafts and flaps of many types, it has not been studied extensively in free tissue transfer. This study was designed to evaluate the effect of hyperbaric oxygen on flap survival when exposed to critical combinations of primary ...
Zhao B - - 1996
The ESR signal of NO bound to hemoglobin was detected during the ischemia-reperfusion of myocardium with low temperature ESR technique, and the synergic effects of NO and oxygen free radicals in the injury of the process were studied with this technique. Oxygen free radicals and NO bound to beta-subunit of ...
Anderson B - - 1996
OBJECTIVE: Captopril, an angiotensin-converting enzyme (ACE) inhibitor, is known to modulate ischemia-reperfusion injury in the isolated hearts. This study was designed to examine the involvement of anti-free radical mechanisms in this protection. METHODS: Isolated perfused rat hearts were subjected to 60 mins of global ischemia and 30 mins of reperfusion ...
Peterson J N - - 1996
The amount of iron in the low molecular weight pool (LMW) increases during no-flow ischemia and is thought to be essential to oxygen radical-derived damage upon reperfusion. Applying three short ischemic periods (5 min) preconditioning before 15 min ischemia results in an improved contractility compared to a direct 15 min ...
Changani K K - - 1996
The aim of this study was to assess the possibility of regenerating nucleotide triphosphates (NTP) in the pig liver following its harvest and subsequent storage on ice. This study has used a pig model that allowed human donor liver retrieval techniques and methods of storage to be utilized. In vitro ...
Tiefenbacher C P - - 1996
BACKGROUND: A deficit in the endothelial production of nitric oxide (NO) is associated with the sequelae of reperfusion injury. Because endothelial NO synthesis depends on the cofactor tetra-hydrobiopterin (BH4), we hypothesized that depletion of this cofactor underlies the reduction of endothelium-dependent dilation in reperfusion injury. METHODS AND RESULTS: After occlusion ...
Lukas A - - 1996
OBJECTIVES: Myocardial ischemia results in an early phase of arrhythmias that primarily involves reentrant mechanisms. However, the trigger that initiates reentry remains unknown. We studied the initiation of reentry attending the development of electrical heterogeneity during simulated ischemia in isolated canine right ventricular subepicardium. METHODS: Preparations consisted of thin epicardial ...
Serebruany V L - - 1996
Myocardial stunning (MS) is a transient contractile dysfunction occurring subsequent to an episode of ischemia followed by reperfusion. NPC 15669 is a leumedin, which inhibits leukocyte adhesion to the endothelium by blocking Mac-1 upregulation. The effect of NPC 15669 supplementation on the hemostasis during MS is unknown. We linked the ...
Garnier A - - 1996
The kinetics of alterations in high energy phosphates were studied in isolated rat hearts during single and multiple ischemic preconditioning (IPC) using [31P]-nuclear magnetic resonance (NMR) spectroscopy. Aortically perfused hearts were subjected to a 25 min sustained ischemia and a 30 min reperfusion. The IPC protocols used a basic pattern ...
Krittayaphong R - - 1996
We examined the relation between anginal symptoms and ischemic indexes during ischemia on exercise testing and daily activities in 76 patients (59 men and 17 women, mean age 61.5 years) with documented coronary artery disease and exercise-induced ischemia. All patients underwent upright bicycle exercise testing and 48-hour ambulatory electrocardiographic monitoring ...
Wesson D E - - 1996
We examined the components of net HCO3 reabsorption (H+/HCO3 secretion and transepithelial HCO3 permeability) in in vivo perfused distal tubules of anesthetized rats to determine the mechanisms by which dietary HCO3 reduces acidification in this nephron segment. Animals eating a minimum electrolyte diet drank either (in mM) 80 NaHCO3, 80 ...
Sharoni R - - 1996
Exposure to a short ischemic period (ischemic preconditioning, IP) will protect the heart from damage following a subsequent longer ischemic episode. The aim of the study was to test whether IP is cardioprotective in the setting of repeated ischemia-reperfusion cycles. Thus, Langendorff-perfused hearts, exposed to IP, were subjected to three ...
Fu L W - - 1996
Abdominal ischemia activates ischemically sensitive sympathetic visceral afferents and evokes reflex excitation of the cardiovascular system. These afferents respond to ischemic metabolites, including lactic acid, bradykinin, prostaglandins, and reactive oxygen species. Severe hypoxemia also has been shown to activate these afferents. It is not known, however, if the regional tissue ...
Kimose H H - - 1996
Increased glutamate utilization is a part of the metabolic adaptation to oxygen deprivation by the heart. The effect of low-dose L-glutamate (2 mmol/L) during continuous reperfusion after aortic unclamping on postcardioplegic recovery was studied in pig hearts similar in size, anatomy, and function to the human adult heart. After cold ...
Gambelunghe C - - 1996
The early effects of 5 or 10 min global cerebral ischemia, sham operation and halothane anesthesia were evaluated in Mongolian gerbils by means of electroencephalography (EEG), neurological examination and passive avoidance training. The "ischemia-sensitive" gerbils (33% and 64% of the 5 and 10 min ischemic groups, respectively) died during carotid ...
Demaison L - - 1996
The purpose of this study was to evaluate the oxidative capacities and the rate of energy synthesis in isolated mitochondria extracted from normal and post-ischemic myocardium. Isolated rat hearts were perfused according to the working mode with a Krebs Heinseleit buffer containing glucose (11 mM), insulin (10 IU/l) and caprylic ...
Vincent J L - - 1996
Multiple organ failure (MOF) stems from a complex interaction between the host's immune response and inadequate tissue perfusion. Prevention of MOF therefore addresses these two components. The risk of inflammation is reduced through treatment of any infection and early stabilization of traumatized regions. Adequate respiratory and cardiocirculatory resuscitation is achieved ...
McAnulty J F - - 1996
Recent advances have led to increased use of ultraprofound hypothermia for cardiopulmonary bypass, organ preservation and trauma patients and have introduced the possibility of targeted pharmacologic intervention during the hypothermic period. In this study, rabbit renal cortex slices were used to examine the effect of administering quinacrine (100 microM) during ...
Avkiran M - - 1996
We studied the effects of acidic reperfusion on 1) the incidence of ventricular fibrillation (VF) and 2) sarcolemmal Na(+)-K(+)-adenosinetriphosphatase (ATPase) activity. Isolated rat hearts (n = 12/group) were subjected to independent perfusion (15 min) of left and right coronary beds with pH 7.4 buffer followed by zero-flow ischemia (10 min) ...
Riepe M W - - 1996
N2-laser-induced fluorescence in combination with the time and spectral resolution of fluorescent NADH molecules allows on-line measurement of relative NADH concentration with high spatial resolution (diameter of optical fibre 200 microns, lambda(exc) = 337 nm, lambda(det) = 460 nm). Energy metabolism was impaired in submerged rat hippocampal slices using the ...
Timmons J A - - 1996
Skeletal muscle contractile function is impaired during acute ischemia such as that experienced by peripheral vascular disease patients. We therefore, examined the effects of dichloroacetate, which can alter resting metabolism, on canine gracilis muscle contractile function during constant flow ischemia. Pretreatment with dichloroacetate increased resting pyruvate dehydrogenase complex activity and ...
Latini S - - 1996
Adenosine outflow and adenosine and adenine nucleotide content of hippocampal slices were evaluated under two different experimental conditions: ischemia-like conditions and electrical stimulation (10 Hz). Five minutes of ischemia-like conditions brought about an 8-fold increase in adenosine outflow in the following 5 min during reperfusion, and a 2-fold increase in ...
Higuchi T - - 1996
The time course, anatomic distribution, and extent of changes in cerebral lactate, N-acetyl-L-aspartate (NAA), and other metabolite levels determined by three-dimensional in vivo 1H magnetic resonance spectroscopy and single-voxel spectral analysis after middle cerebral artery occlusion in rats. Increased lactate was detected in the central ischemic region within 1.3 hours ...
Bast G E - - 1996
Rabbit ears were single-pass perfused with a buffer solution containing either 6% hetastarch or 5% bovine serum albumin. Hydrocortisone 21-butyrate (5 mM), diflunisal (17 mM) or permethrin (33 mM) was added to isopropyl myristate with 5% polyethylene, and applied to about 40% of the epithelial surface area of the ear. ...
Lazar H L - - 1995
BACKGROUND: Leukocyte depletion (LD) has been shown to be beneficial during the reperfusion of acutely ischemic myocardium; however, its role during cardiopulmonary bypass (CPB) in hearts protected with blood cardioplegia (BCP) is unknown. This experimental study sought to determine whether LD filters inserted in the CPB circuit before cardioplegic arrest ...
Erbas D - - 1995
1. An experimental comparative study on isolated guinea pig lungs was carried out to determine the effect of selenium added to pulmoplegic solution on ischemic lung preservation. 2. Two different types of solutions (Eurocollins in control group and Eurocollins + selenium 10(-3) M in experimental group) were infused before 3 ...
Schoenberg M H - - 1995
Hemorrhagic mucosal lesions are produced during intestinal ischemia and after reperfusion due at least in part to the accumulation and activation of polymorphonuclear leukocytes in the tissue. It has been shown in vitro that adenosine is instrumental in attenuating this pathophysiological process. Acadesine [5-amino-4-imidazolecarboxamide (AICA) riboside], a purine nucleoside analogue, ...
Gonce M E - - 1995
Liver ischemia is purposefully induced by portal triad occlusion (PTO) in several clinical situations including liver surgery for trauma, tumor, and transplantation. Despite significant morbidity from PTO, the hemodynamic and metabolic effects of PTO have not been evaluated relative to duration of ischemia. We investigated this using a total hepatic ...
Peitzman A B - - 1995
A great deal has been learned about the pathophysiologic condition of hemorrhagic shock. The response of the hormonal and inflammatory mediator systems in patients in hemorrhagic shock appears to represent a distinct set of responses different from those of other forms of shock. The classic neuroendocrine response to hemorrhage attempts ...
Blumenthal J A - - 1995
BACKGROUND: The purpose of this study was to determine the correspondence of mental stress-induced ischemia in the laboratory with ambulatory ischemia and to assess the relationship between hemodynamic responses to mental stress and the occurrence of ischemia. Although exercise testing is usually used to elicit myocardial ischemia, ischemia during daily ...
Choi K T - - 1995
Glutamate (GLU) is a neurotransmitter. Massive release of GLU and glycine (GLY) into the brain's extracellular space may be triggered by ischemia, and may result in acute neuronal lysis or delayed neuronal death. The aim of this study was to evaluate the possible relationship between hyperventilation and the level of ...
Cordeiro P G - - 1995
In this report, we discuss application of the noninvasive technology of ultraviolet fluorescence spectroscopy to the metabolic analysis of normal and compromised myocutaneous flaps. Acute changes in tissue redox states during ischemia and reperfusion were determined analysis of changes in the fluorescence spectrum of reduced nicotinomide adenine dinucleotide (NADH). Analysis ...
Schulz R - - 1995
OBJECTIVES: Nitric oxide (NO) exerts both protective and detrimental actions in a variety of biological systems. During acute reperfusion following myocardial ischaemia, a rapid overproduction of free radicals, including NO, may occur. We investigated the effects of the NO synthase inhibitors NG-nitro-L-arginine methyl ester (L-NAME) and NG-monomethyl-L-arginine (L-NMMA), and the ...
Gupta D K - - 1995
A prospective double blind cross over study compared the anti-ischemic effect of 20 mg of isosorbide-5-mononitrate (IS-5-MN), 60 mg of diltiazem and 100 mg of metoprolol by performing serial treadmill tests (TMTs) following oral administration of single dose of each drug in 28 patients of ischemic heart disease with positive ...
Corsi C - - 1995
The hemodynamic effect of L-propionylcarnitine (LPC) administered intravenously was evaluated in a double-blind, randomized, three-period crossover study in 12 men (aged sixty to seventy-five years) with Leriche-Fontaine stage II peripheral arterial disease of lower limbs. At baseline, maximum working capacity of each patient was determined by a standardized ergometric test. ...
Stewart R A - - 1995
Warm-up exercise can significantly reduce the severity of myocardial ischemia on exercise after a 10-minute rest, but this benefit is significantly less after a 30-minute rest. Further study is needed to clarify the mechanisms responsible for warm-up. The results of this study are consistent with a change in myocardial metabolism ...
Hamra M - - 1995
Whether exercise protects the myocardium from arrhythmias during ischemia (ISC) or alters electrophysiology is controversial. We used microelectrode techniques in isolated cardiac fibers from exercise-trained (ET: 8-10 wk daily exercise) and sedentary (SED: 8-10 wk cage-rest) dogs to examine the effect of exercise on cellular electrophysiology during simulated ISC. We ...
Madden M C - - 1995
Carnitine palmitoyltransferase-I (CPT-I) inhibitors improve postischemic myocardial function either by decreasing muscle long-chain acylcarnitines (LCAC) during ischemia or by increasing oxidation of alternate substrates such as glucose during reperfusion. These possibilities were evaluated using oxfenicine, a CPT-I inhibitor, and alternate substrates that bypass carnitine-dependent metabolism. Isolated rat hearts subjected to ...
de Groot M J - - 1995
Previous studies have shown that exogenous lactate impairs mechanical function of reperfused ischaemic hearts, while pyruvate improves post-ischaemic recovery. The aim of this study was to investigate whether the diverging influence of exogenous lactate and pyruvate on functional recovery can be explained by an effect of the exogenous substrates on ...
Segerdahl M - - 1995
The effect of adenosine on tactile allodynia (secondary hyperalgesia) was studied in 6 healthy volunteers, using a double-blind, placebo controlled, cross-over design. Tactile allodynia was induced by topical application of mustard oil on the skin of the volar aspect of the forearm. Adenosine (50 micrograms kg-1 min-1) or saline was ...
Oredsson S - - 1995
OBJECTIVE: To study the effect of polymorphonuclear leucocytes (PMNLs) on reperfusion injury in rabbit skeletal muscle and to evaluate the role of oxygen-derived free radicals in PMNL-mediated reperfusion injury. EXPERIMENTAL DESIGN: An isolated rabbit limb perfusion model. Amputated hindlimbs were subjected to 4 hours of ischaemia followed by 2 hours ...
Hoque A N - - 1995
The effects of dilazep, d-propranolol and lidocaine on the mechanical and metabolic changes induced by lysophosphatidylcholine (LPC) were studied in isolated, perfused working rat heart. After a stabilization period, the heart was perfused for 5 min with LPC (10 microM) alone, LPC plus dilazep (5, 10 or 20 microM), LPC ...
Shuaib A - - 1995
Repetitive ischemia may result in more severe damage than a single similar duration insult. Inter-ischemic hypothermia significantly decreases this damage. It is unclear if protection would be evident if cooling was delayed until after the repeated insults. In this study, we evaluated the effects of 3 h of mild cooling ...
Lerman B B - - 1995
BACKGROUND: The single most important determinant of cardiac arrest outcome is the duration of ventricular fibrillation (VF) preceding delivery of a high-energy shock, because of the adverse effect of VF duration on defibrillation threshold (DFT). Although a metabolic mechanism has been proposed, hypoxia, metabolic acidosis, or alkalosis do not adversely ...
Dyck J R - - 1995
OBJECTIVE: The aim was to examine the regulation of the cardiac Na+/H+ exchanger NHE-1 isoform mRNA in response to ischaemia and acidosis in the mammalian myocardium. METHODS: Male Sprague Dawley rat hearts were perfused in a non-circulated retrograde fashion according to the Langendorff method. Hearts were perfused for 3 h ...
Sugimoto S - - 1995
BACKGROUND: Drug-induced opening of the adenosine triphosphate-sensitive potassium channel (KATP) during hypoxia and/or ischemia, achieved significant myocardial protection in several in vitro and in vivo models. Pretreatment with KATP openers simulated preconditioning and thus enhanced recovery from ischemia. We have demonstrated that the risk of hypoxia-induced myocardial stunning is reversed ...
Tarn D M - - 1996
This study examines whether electroretinogram recovery after short-term (15- or 20-min) ischemia is enhanced by agents (catalase and dextromethorphan) that are known to enhance recovery after longer (60-75 min) periods of ischemia. Under both light-adapted and dark-adapted conditions, Dutch rabbits were exposed to two sequential sets of short-term ischemia, each ...
Gutierrez G - - 1995
In many critically ill patients, systemic measures of hemodynamic and O2 transport variables may not be sufficiently sensitive to portray the complex interaction between energy requirements and energy supply in all tissues. Gastric or intestinal tonometry has been proposed as a relative noninvasive index of the adequacy of aerobic metabolism ...
Daxnerová Z - - 1995
Ischemia and reperfusion-induced nuclear and nucleolar changes of the lumbosacral dorsal root ganglia neurons were studied in a spinal cord ischemic model of a rabbit. Twenty and forty min abdominal aorta ligation followed immediately by perfusion fixation, 20 min abdominal aorta ligation followed by 1 h of normoxic reoxygenation and ...
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