Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Direct monitoring of myoglobin efflux during ischemia and reperfusion has been limited because of inherent sample collection problems in the ischemic region. Recently, the cardiac dialysis technique has offered a powerful method for monitoring myocardial interstitial levels of low-molecular-weight compounds in the cardiac ischemic region. In the present study, we extended the molecular target to high-molecular-weight compounds by use of microdialysis probes with a high-molecular-mass cutoff and monitored myocardial interstitial myoglobin levels. A dialysis probe was implanted in the left ventricular free wall in anesthetized rabbits. The main coronary artery was occluded for 60 or 120 min. We examined the effects of myocardial ischemia and reperfusion on myocardial interstitial myoglobin levels. Interstitial myoglobin increased within 15 min of ischemia and continued to increase during 120 min of ischemia, whereas blood myoglobin increased at 45 min of ischemia. Lactate and myoglobin in the interstitial space increased during the same period. At 60 min of ischemia, reperfusion markedly accelerated interstitial myoglobin release. The interstitial myoglobin level was fivefold higher at 0-15 min of reperfusion than at 60-75 min of coronary occlusion. The dialysis technique permits earlier detection of myoglobin release and separately monitors myoglobin release during ischemia and reperfusion. Myocardial interstitial myoglobin levels can serve as an index of myocardial injury evoked by ischemia or reperfusion.
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PMID:Microdialysis separately monitors myocardial interstitial myoglobin during ischemia and reperfusion. 1583 97

The existing markers for myocardial necrosis, such as cardiac troponin, creatine kinase-MB, and myoglobin are thought to be released into blood following irreversible myocardial necrosis. Thus results of these tests are usually negative for patients with acute coronary syndromes (ACS) who present to the emergency department (ED) within the first 3 hours after the onset of chest pain. Given the need to make early therapeutic and triage decisions, biomarkers that can be used to diagnose and/or risk stratify ACS patients during their initial ED presentation will be important. Active research in this area has identified several classes of biomarkers that show promise for early detection of disease. These include tests for the presence of acute inflammation and infiltration (e.g., high sensitivity-C-reactive protein, myeloperoxidase), plaque instability (e.g., pregnancy-associated plasma protein-A, placental growth factor), platelet activation (e.g., whole blood choline, platelet density, CD40 ligand), and myocardial ischemia (e.g., ischemia modified albumin, free fatty acids, serum choline, and B-type natriuretic peptide). Each of these tests has demonstrated some utility for early diagnosis. However, as most lack specificity for myocardial disease, routine use may require a multi-marker approach.
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PMID:Markers for early detection of cardiac diseases. 1611 68

The measurement of cardiac troponins has emerged as the biochemical "gold standard" for the diagnosis and management of patients with acute chest pain. However, earlier markers should support investigation strategies, as several patients with acute coronary syndrome might present with non-diagnostic concentrations. Ischemia-modified albumin (IMA), measured by the albumin cobalt binding (ACB) assay, was recently proposed for early detection of myocardial ischemia. To establish the potential influence of endurance training on the diagnostic approach to patients with suspected myocardial injury, cardiac troponin T (cTnT), creatine kinase isoenzyme MB (CK-MB), myoglobin and IMA were evaluated in healthy individuals subjected to different aerobic workloads. The concentrations of both IMA and CK-MB were significantly increased in athletes subjected to high-workload endurance training, whereas the concentration of cTnT and myoglobin was not influenced by physical exercise in the medium term. Taken together, our results demonstrate that demanding aerobic physical activity might influence the generation of IMA, which might be increased in the medium term following high-workload endurance training, while the concentration of other conventional markers of myocardial injury remains non-diagnostic.
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PMID:High-workload endurance training may increase serum ischemia-modified albumin concentrations. 1620 35

Cardiotoxicity is a serious adverse effect of chemotherapy that encompasses a spectrum of disorders, ranging from relatively benign arrhythmias to potentially lethal conditions such as myocardial ischemia/infarction and cardiomyopathy. The toxicity of chemotherapeutic drugs can cause loss of myocytes' sarcolemmal integrity, release of bioactive markers into the extracellular environment (tissue and circulation) and ultimately leading to the necrosis of myocytes. The extent and severity of the necrosis can be monitored by the levels of bioactive markers. Therefore current research is aimed at finding biochemical markers with absolute cardiac specificity, high sensitivity and predictive value that can be used in early detection of patients with treatment-induced myocardial damage. Routinely used biomarkers like CK, CK-MB, and myoglobin do not meet the stated criteria. Their role in early diagnosis of chemotherapy- induced myocardial toxicity is controversial and limited. However, cardiac troponins, new nonconventional markers, have shown promising results in assessment and monitoring of both, early and late, clinical and subclinical damage to myocardium after chemotherapy. The article reviews clinical studies evaluating the role of cardiac troponins in the diagnosis of cardiotoxicity and their use in the management of cancer survivors.
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PMID:Cardiac troponins--biochemical markers of cardiac toxicity after cytostatic therapy. 1665 86

Hydrogen peroxide (H2O2) is implicated in cardiac myocyte (CM) damage during myocardial ischemia-reperfusion (IR) injury. Myoglobin (Mb) is present in CM at significant concentrations and reacts with H2O2 to yield one- and two-electron oxidants that may promote myocardial injury. Paradoxically, hearts from mice lacking Mb are more susceptible to H2O2-induced dysfunction than the corresponding controls [U. Flogel, A. Godecke, L.O. Klotz, J. Schrader, Role of myoglobin in the anti-oxidant defense of the heart, FASEB J. 18 (2004) 1156-1158]. We have overexpressed wild-type or Y103F variant of human Mb in cultured CMs to test whether Mb protects against H2O2 insult. Contrary to expectation, cells expressing WT or the Y103F Mb show increased mitochondrial dysfunction and apoptosis, and decreased ATP in response to H2O2 that follows the order native < Y103F Mb < WT human Mb consistent with the increasing pro-oxidant activity for these proteins. These data indicate that (i) Mb promotes oxidative damage to cultured CM and (ii) Mb may be a useful target for the design of inhibitors of myocardial IR injury.
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PMID:Expression of human myoglobin in H9c2 cells enhances toxicity to added hydrogen peroxide. 1688 98

The commonly used laboratory markers of coronary involvement in subjects with acute coronary syndrome (ACS) are not yet myocardial ischemia-specific and show a late irreversible involvement of the myocardium. A laboratory test has been searched for in order to distinguish persons with myocardial ischemia and typical CAD symptoms to CAD-free individuals. Reg-Ialpha is the product of Reg-I gene which plays a significant role in myocardial regeneration. 38 individuals with suspicion of acute coronary syndrome were tested on admission, after 2 and 6 hours. In all of them cardiac troponin I, myoglobin, C-reactive protein (CRP) and Reg-I alpha were analysed. Our findings did not support the hypothesis that measurement of Reg-Ia maybe the useful marker of myocardial stress.
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PMID:Reg-Ialpha in the diagnosis of acute coronary syndrome--a pilot study. 1693 8

Myocardial damage is a frequent complication of cardiac surgery by direct mechanical trauma during the surgical procedure and by myocardial ischemia, which occurs during the cardiopulmonary bypass (CBP). Because the concentrations of biomarkers in the blood collected from the coronary sinus are the best witness of the myocardial damages, we measured the levels of specific cardiac troponin I (c-TnI) and nonspecific (adenosine, myoglobin) markers of left ventricular damages in the coronary sinus of patients during cardiac surgery. Thirty patients who underwent aortic valve replacement for aortic stenosis were included. Blood samples were collected in the coronary sinus and in the radial artery at the beginning (T0), at the end of the CBP (T1), and then 24 hours later (T2). At T0 and T1, adenosine, c-TnI, and myoglobin levels were significantly higher in the coronary sinus than in the radial artery (T0: adenosine: mean +27%; c-TnI: +41%; myoglobin: +28%; T1: adenosine: mean +58%; c-TnI: +58%; myoglobin: +25%; p < .001). These parameters were significantly higher in the coronary sinus at T1 compared with T0 (adenosine: +50%; c-TnI: +229%; myoglobin: +94%; p < .01) and in the radial artery (adenosine: +21%; c-TnI: +194%; myoglobin: +98%; p < .01). At T2, c-TnI further increased. Damages to the myocardium during cardiac surgery are minimal in our surgical conditions but are probably underestimated when using markers measured at the peripheral level. However, most of the damages appear several hours after the surgery.
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PMID:Release of markers of myocardial damage evaluated in the coronary sinus during cardiac surgery. 1765 74

The aim of this study was to evaluate the time course events of cellular damage during myocardial ischemia and reperfusion injury in rats and to find out a correlation between the structural alterations with respect to the biochemical changes. Cardiac biomarkers and lysosomal enzymes viz. cathepsin D, acid phosphatase and beta-glucuronidase and matrix metalloproteinases (MMPs) were evaluated at different time points, in response to ischemia-reperfusion induced oxidative stress in an isolated rat heart model perfused in Langendorff mode. Microscopically, changes in myocardial architecture, myofibrillar degradation, and collagen (COL) integrity were studied using hematoxylin-eosin, Masson's trichrome and toluidine blue staining techniques. A three-fold increase in the level of myoglobin was observed after 30 min of ischemia followed by 120 min of reperfusion as compared to 15 min ischemia, 120 min reperfusion. Similarly, a significant increase (P<0.05) in the levels of lipid peroxides and superoxide anion coupled with a decrease in enzymatic and nonenzymatic antioxidant levels were observed. A concomitant increase in the activity of cathepsin D (24.07+/-0.95) and a higher expression of MMPs after 120 min of reperfusion following 30 min ischemia were shown to correlate with the myocardial damage as shown by histopathology, suggesting that free radical induced activation of cathepsin D and MMPs could mediate early damage during myocardial ischemia and reperfusion.
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PMID:Myocardial ischemia and reperfusion injury in rats: lysosomal hydrolases and matrix metalloproteinases mediated cellular damage. 1834 82

The postmortem diagnosis of acute myocardial infarction represents a current challenge for forensic pathologists, particularly when death occurs within minutes to a few hours after the ischemic insult. Among the adult population the single most important cause of sudden cardiac death (SCD) is the well-known atherosclerotic coronary artery disease, commonly asymptomatic or unrecognized. The recognition of early myocardial damage using routine hematoxylin and eosin (H&E) staining is possible only if death has occurred at least 6 hours after the onset of the ischemic injury. The usefulness of immunohistochemical markers to the diagnosis of early myocardial damage has been recently suggested because most of them can be visible even serologically as early as few minutes after the beginning of the symptoms. To evaluate the usefulness of plasma and cellular antigens, their distribution patterns have been studied among a group of 18 SCD cases in which a myocardial ischemia was strongly suspected. For the present study, 4 markers have been selected on the basis of their different diagnostic potential as follows: among the plasma markers the C5b-9 and fibronectin, among the cellular markers the myoglobin and cardiac troponin. The results show that only the study of multiple markers such as those selected can provide enough evidence of myocardial ischemia and/or necrosis, supporting the final diagnosis of SCD. No single immunohistochemical staining is ideal for diagnosing early myocardial ischemia but a set of markers can improve the ability of forensic pathologists to detect ischemic areas when no macroscopic or microscopic evidence of necrosis is available. However, the interpretation of data obtained in each individual cannot be isolated from the overall assessment of the factors (cardiopulmonary resuscitation and/or agonal artifacts) that can affect the expression of each marker.
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PMID:Sudden cardiac death and myocardial ischemia indicators: a comparative study of four immunohistochemical markers. 1852 Apr 84

Nitric oxide (NO) may limit myocardial ischemia-reperfusion injury by slowing the mitochondrial metabolism. We examined whether rat heart contains catalysts potentially capable of reducing nitrite to NO during an episode of regional myocardial ischemia produced by temporary coronary artery occlusion. In intact Sprague-Dawley rats, a 15-min coronary occlusion lowered the nitrite concentration of the myocardial regions exhibiting ischemic glucose metabolism to approximately 50% that of nonischemic regions (185 +/- 223 vs. 420 +/- 203 nmol/l). Nitrite was rapidly repleted during subsequent reperfusion. The heart tissue tested in vitro acquired a substantial ability to consume nitrite when made hypoxic at neutral pH, and this ability was slightly enhanced by simultaneously lowering the pH to 5.5. More than 70% of this activity could be abolished by flushing the coronary circulation with crystalloid to remove trapped erythrocytes. Correspondingly, erythrocytes demonstrated the ability to reduce exogenous nitrite to NO under hypoxic conditions in vitro. In erythrocyte-free heart tissue, the nitrite consumption increased fivefold when the pH was lowered to 5.5. Approximately 40% of this pH-sensitive increase in nitrite consumption could be blocked by the xanthine oxidoreductase inhibitor allopurinol, whereas lowering the Po(2) sufficiently to desaturate myoglobin accelerated it further. We conclude that rat heart contains several factors capable of catalyzing ischemic nitrite reduction; the most potent is contained within erythrocytes and activated by hypoxia, whereas the remainder includes xanthine oxidoreductase and other pH-sensitive factors endogenous to heart tissue, including deoxymyoglobin.
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PMID:Nitrite consumption in ischemic rat heart catalyzed by distinct blood-borne and tissue factors. 1882 31


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