Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.1 (ERK)
 95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An important aspect of infection by the human immunodeficiency virus (HIV-1) type 1 is its long clinical latency period, suggesting that the provirus may remain latent for extended periods of time after primary infection. Numerous factors such as cytokines, tumor promoters, co-infection by several viruses and physical agents are able to reactivate latent virus. Since a common denominator, shared by several of these agents, is their ability to cause stress conditions, we have examined the effects of an oxidative stress mediated by reactive oxygen species on HIV-1 latently infected monocytes (U1) or lymphocytes (ACH-2). Exposure of these two cell lines to hydrogen peroxide causes a decrease of cell viability but among the cells surviving the treatment, a HIV-1 reactivation can be observed as measured by increased RT activities depicted in cell supernatants or by the appearance of HIV-1 antigens inside cells. Singlet oxygen (1O2) when generated either in the cytoplasm or in the cell nucleus can also promote an important HIV-1 reactivation from treated cells. However, extracellular generation of 1O2 cannot trigger the HIV-1 reactivation although this kind of treatment is highly cytotoxic. These experiments demonstrate that different reactive oxygen species are able to lead to an intracellular pro-oxidant state initiating one or several signalling pathways which lead in fine to the HIV-1 LTR transactivation by regulatory proteins.
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PMID:HIV-1 reactivation after an oxidative stress mediated by different reactive oxygen species. 819 37

Production of reactive oxygen metabolites by the NADPH oxidase is an essential mechanism underlying the microbicidal role of phagocytes. Receptor-mediated activation of the oxidase was originally thought to be mediated by calcium and/or by protein kinase C (PKC). However, recent evidence suggests that additional signalling pathways exist. In this article the possible role of tyrosine phosphorylation is discussed. In addition, results obtained using an in vitro kinase renaturation assay are described. The latter assay revealed the existence of at least four serine/threonine kinases that are activated in cells stimulated with chemoattractants. One of these, of molecular weight 41,000 was identified as a member of the ERK or MAP-kinase family. The existence of multiple, possibly redundant or synergistic signaling pathways is considered.
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PMID:Involvement of multiple kinases in neutrophil activation. 831 67

The response of the myocardium to prolonged or chronic ischemia may differ from the well documented changes that occur acutely subsequent to the onset of hypoperfusion. Therefore, we have examined in an instrumented canine model and using spatially localized spectroscopy to achieve transmural differentiation, the myocardial HEP and Pi levels as well as wall thickening in situ during prolonged ischemia induced by sustained coronary artery stenosis. The results demonstrate that subtotal coronary artery occlusion causes immediate and transmurally inhomogeneous decreases in the myocardial HEP content and increase in the Pi/CP ratio; however, during prolonged mild hypoperfusion, metabolic changes occur which lead to statistically significant recovery of CP (but not ATP) and disappearance of Pi despite the persistence of reduced blood flow and oxygen supply. Upon release of the occlusion, the previously ischemic muscle recovered blood flow, and some (but not all) of its preischemic contractile function without parallel changes in the HEP levels. It is concluded that normal HEP and Pi levels cannot be equated with either the absence of underperfusion or insensitivity of NMR spectroscopy to ischemia. Rather, it is imperative that both functional and spectroscopic measurements are performed simultaneously to distinguish between ischemic myocardium which is adapted versus unadapted to the hypoperfusion.
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PMID:Responses of myocardial high energy phosphates and wall thickening to prolonged regional hypoperfusion induced by subtotal coronary stenosis. 837 71

We have studied two babies with Hb H disease from birth to about six months of age and analyzed the changes in the relative quantities of the five globin chains (zeta, alpha, beta, G gamma, A gamma) and the four hemoglobins (Hb F, Hb A, Hb Bart's, Hb H) using different high performance liquid chromatography procedures. The types of Hb H disease were -(SEA)/-alpha(3.7 kb) and -(Fil)/-alpha(3.7 kb); the larger -(Fil) deletion includes the functional zeta 2-globin gene, explaining the higher zeta chain level in the baby with the -(SEA)/-alpha(3.7 kb) type. The functional hemoglobin level at birth (Hb A+Hb F) was 11 to 12 g/dl with 3 to 4 g/dl Hb Bart's (gamma 4). Only 5% of the "fast-moving" hemoglobin was Hb H (beta 4). The level of Hb F at birth was low (less than 50% of the total Hb A+Hb F). After birth, the alpha and gamma chain production decreases rapidly resulting in a severe anemia (total functional hemoglobin approximately 7 g/dl) at 30 to 60 days postnatally, improving gradually to 8.5-9.5 g/dl at age of three months. The preferential formation of Hb A over Hb F at birth, and presumably prenatally, has the advantage that the level of the highly unstable Hb H is kept low; it also results in low levels of Hb F impairing the oxygen transfer capability of the fetal blood.
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PMID:Postnatal changes in the quantities of globin chains and hemoglobin types in two babies with Hb H disease. 841 3

The present study compares the effect of organ preservation with Euro-Collins solution, cardioplegic histidine-tryptophan-ketoglutarate solution, and University of Wisconsin solution on immediate pancreatic function after cold storage at 4 degrees C for 24 hr. Postischemic organ quality of a porcine pancreas preparation was tested by quantification of physiological and biomedical parameters in a one-line reperfusion system. During reperfusion with a constant arterial pressure the arteriovenous flow rate was significantly higher for HTK (5.7 +/- 0.91 ml/min, n = 8; P < 0.05 vs. EC) and UW (7.4 +/- 0.81 ml/min, n = 8; P < 0.05 vs. EC) than for EC (3.0 +/- 0.26 ml/min, n = 6). The lowest lactate content in the reperfusate was found after HTK protection (HTK, 64.0 +/- 7.2 mumol/50 ml, n = 8; versus EC, 114.2 +/- 1.7 mumol/50 ml, n = 6, P < 0.001; versus UW, 148.0 +/- 28.6 mumol/50 ml, n = 8, P < 0.05). Amylase in the venous effluent was significantly lower (P < 0.05) for HTK or UW protection than for EC (HTK, 189 +/- 72.6 U/ml; UW, 188 +/- 39.4 U/ml; EC, 416 +/- 71.7 U/ml). Oxygen consumption during reperfusion was significantly higher for HTK (2.15 +/- 0.22 microliters/g/min, P < 0.001) and UW (1.80 +/- 0.52 microliters/g/min, P < 0.05) than for EC (0.47 +/- 0.13 microliters/g/min). We conclude that immediate postischemic organ quality and pancreatic function after protection with HTK is not inferior to preservation with UW.
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PMID:The effect of different solutions for organ preservation on immediate postischemic pancreatic function in vitro. 842 35

The responses to a self-selected stepping pattern (random) on a StairMaster 4000PT were compared with those obtained in response to the rates established by the manufacturer (cadence) in men (N = 14) and women (N = 14). During the random test the subjects stepped at their own natural, self-selected rate and distance. In cadence trial the subjects were required to step in time with a metronome at a predetermined rates of 60, 77, 95, and 112 steps.min-1. Each trial consisted of four, 5-min continuous workloads during which HRs were recorded and expired air was analyzed using an automated open-circuit gas system each minute. All size dependent variables (i.e., VE and lO2.min-1) as well as relative VO2 (mlO2.kg-1.min-1) were significantly (P < 0.01) higher for the men across all stages and between methods. Although the random test produced slightly higher oxygen consumption values than the cadence trial, these differences were not significant (P > 0.05). The actual METs were significantly (P < 0.01) higher at all stages except at the lowest stepping rate for both methods compared with those estimated by the manufacturer. Equations were established to estimate actual MET costs: Men's METs = 2.675 + 0.935 (rate); women's METs = 2.934 + 0.817 (rate). Cross-validations of 0.975 and 0.957 were obtained on an additional group of men (N = 8) and women (N = 11), respectively.
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PMID:Effect of stepping rate on energy costs during StairMaster exercise. 845 54

Vascular endothelial cell growth factors (VEGF) are key modulators of endothelial cell growth and function. The class III receptor tyrosine kinases KDR and Flt-1 are high affinity receptors for VEGF, while Flt-4 is a receptor for the recently identified VEGF-C. We have examined the expression of flt-1, flt-4 and KDR in human microvascular and large vessel endothelial cells and in a variety of other cell types in vitro. Endothelial cells proliferated and exhibited increased procoagulant activity in response to VEGF. Flt-1, flt-4 and KDR were detected in both freshly isolated endothelial cells, and in sparse and confluent endothelial cell cultures by RT-PCR. Attempts to modulate receptor expression by culturing cells at reduced oxygen tensions (2%) did not induce consistent changes in flt-1, flt-4 or KDR expression. Incubation with tumor-conditioned medium or co-culture of endothelial cells with a range of breast and small cell lung carcinoma cell lines did not reproducibly alter receptor mRNA expression. However, flt-1, flt-4 and KDR transcript levels were enhanced following treatment with tetradecanoylphorbol acetate.
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PMID:Coexpression of flt-1, flt-4 and KDR in freshly isolated and cultured human endothelial cells. 863 24

Myocardial infarction in consequence of a coronary artery occlusion presents a serious problem. It is the aim of any emergency revascularization to minimize the ischemia-induced damage or to salvage reversibly injured myocardium. In experiments on 8 anesthetized pigs, myocardial protection by orthograde perfusion with a high-volume cardioplegic solution was studied under controlled conditions. The left anterior descending artery (LAD) was occluded for 60 min. Then cardiopulmonary bypass was instituted and cardioplegia induced by 8 min perfusion of Bretschneider HTK solution into the aortic root. After 15 min global ischemia, the LAD was "revascularized' and 150 min reperfusion followed. Except for the early relaxation (dP/dtmin) and mean thickening velocity in the ischemic myocardium, all variables remained essentially unchanged during LAD occlusion. During the entire reperfusion, heart rate was significantly increased compared to control: 93 +/- 23 vs. 126 +/- 20/min. Left-ventricular (LV) peak pressure was significantly decreased at the end of the reperfusion, 104 +/- 33 and 77 +/- 22 mmHg, as was dP/dtmax:2155 +/- 655 vs. 1720 +/- 895 mmHg/s. Cardiac output was insignificantly decreased at the end of reperfusion, 2.6 +/- 0.6 vs. 2.4 +/- 0.5 L/min, whereas stroke-work index exhibited a significant deterioration: 1.2 +/- 0.6 vs. 0.5 +/- 0.3 mmHg.ml/kg. LV dP/dtmin was significantly impaired after ischemia and at the end of reperfusion, -1575 +/- 385 vs. -855 +/- 310 mmHg/s, while LV end-diastolic pressure exhibited only a moderate increase: 8 +/- 5 vs. 9 +/- 3 mmHg. MVO2, in turn, remained almost constant throughout the protocol for each of two methods by which it was predicted. The results show that global work, MVO2, and external efficiency were unchanged during early and late occlusion compared to control. During the entire reperfusion the myocardium was stunned, i.e. cardiac work was decreased at maintained MVO2. Thus, external efficiency was decreased. From these results we conclude that in reperfused myocardium after cardioplegic arrest, the oxygen is only inefficiently converted to develop force.
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PMID:Cardiac efficiency during coronary occlusion and during reperfusion after emergency revascularization under cardioprotection. 872 96

The aim of this study was determine the effect of a 15-week individualized exercise conditioning program on glycosylated hemoglobin (HbAlc) levels on Type 2 diabetes. Thirty-nine participants were sedantary, Type 2 diabetics, on an oral hypo-glycemic drug and no specified diet regimen at study onset. Pre and post 15 weeks subjects underwent: maximal incremental exercise tests, blood analysis, body composition analysis. Twenty-one subjects were prescribed an individualized exercise program for 15 weeks. Significant differences were found in the exercise group after 15 weeks in: total body fat, trunk fat, peak oxygen consumption and MET values. Correlations existed in the exercise group between HbAlc, arm muscle area and leg lean mass. Sixty-two percent of this group showed a reduction in HbAlc values. For this group, dietary intakes of riboflavin and potassium maybe associated with HbAlc levels. Exercise in conjunction with oral drug therapy prescribed for the NIDDM individual did not directly modify HbAlc levels, but did result in favorable effects on blood lipid values, fitness levels, and body composition values.
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PMID:The effect of exercise conditioning, diet, and drug therapy on glycosylated hemoglobin levels in type 2 (NIDDM) diabetics. 877 76

The purpose of this study was to investigate the importance of subject-related risk factors for sports injuries, taking exposure time into account. At baseline in 182 healthy males and females (27 yr) the following subject-related risk factors were assessed: body mass index (BMI), maximal oxygen uptake (direct treadmill measurement), seven aspects of neuromotor fitness (MOPER fitness test), strength of the hamstring and quadriceps muscles (CYBEX), having sustained a sports injury in the 12 months preceding the baseline measurement ("previous injury"), and 16 psychological and psychosocial factors (measured with 8 standard, valid, and reliable questionnaires). For 1 yr, subjects were asked to make daily entries on a monthly log concerning all sports activities exceeding an intensity of 4 MET and all sustained sport injuries. Completed logs were returned by 139 subjects (75 males and 64 females). Fifty-one injuries were registered in 41 subjects. The overall incidence rate (IR) was 3.7 sports injuries per 1000 h of sports participation (95% confidence interval 2.8-4.9). For various subcategories, the following IR per 1000 h of sports participation were calculated: contact sports IR = 11.0 (95% CI 7.4-16.3); noncontact sports IR = 2.3% (95% CI 1.6-3.3); competition IR = 13.4 (95% CI 8.7-20.6); and training IR = 2.8 (95% CI 1.6-5.1). Data were analyzed by stepwise multiple logistic regression. The following five variables were independent and significant (P < 0.05) predictors of risk in sustaining a sport injury: dominance (odds ratio (OR) = 1.71; 95% CI = 1.44-2.03), vital exhaustion (OR = 1.85; CI = 1.22-2.86), stressful life events (OR = 1.84; 95% CI = 1.10-311); these ORs were calculated for an increase of 10% of the range of obtained scores, starting at minimum value. For total sporting time, the OR was calculated by taking the group with a total sporting time below the median (4050 h) as a reference (OR = 6.87; 95% CI = 2.09-22.55). For previous injury, subjects that had not sustained a sports injury in the 12 months preceding the baseline measurements served as a reference for the calculation of the OR (OR = 9.41; 95% CI = 2.80-31.58). These findings confirm that both exposure time and previous injury are more important predictors of sports injuries than psychological, psychosocial, physiological, and anthropometrical factors.
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PMID:Subject-related risk factors for sports injuries: a 1-yr prospective study in young adults. 888 6


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