Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the role of creatine kinase bound to sarcoplasmic reticulum membranes of fast skeletal muscle in the local regeneration of ATP and the possible physiological significance of this regeneration for calcium pump function. Our results indicate that ADP produced by sarcoplasmic reticulum Ca(2+)-ATPase is effectively phosphorylated by creatine kinase in the presence of creatine phosphate. This phosphorylation is an important function of the membrane-bound creatine kinase because accumulation of ADP has a depressive effect on Ca(2+)-uptake by sarcoplasmic reticulum vesicles. The concentration-dependent depression of Ca(2+)-uptake by ADP was especially pronounced when there was strong back inhibition by high intravesicular [Ca2+]. ATP regenerated by endogenous creatine kinase was not in free equilibrium with the ATP in the surrounding medium, but was used preferentially by Ca(2+)-ATPase for Ca(2+)-uptake. Efficient translocation of ATP from creatine kinase to Ca(2+)-ATPase, despite the presence of an ATP trap in the surrounding medium, can be explained by close localization of creatine kinase and Ca(2+)-ATPase on the sarcoplasmic reticulum membranes. These results suggest the existence of functional coupling between creatine kinase and Ca(2+)-ATPase on skeletal muscle sarcoplasmic reticulum membranes. Several factors (amount of membrane-bound creatine kinase, oxidation of SH groups of creatine kinase, decrease in [phosphocreatine]) can influence the ability of creatine kinase/phosphocreatine system to support a low ADP/ATP ratio and fuel the Ca(2+)-pump with ATP. These factors may become operative in the living cells, influencing functional coupling between creatine kinase and Ca(2+)-ATPase and may have an indirect effect on Ca(2+)-pump function before Ca(2+)-ATPase itself is affected.
 ...
PMID:Functional coupling between sarcoplasmic-reticulum-bound creatine kinase and Ca(2+)-ATPase. 850 36

Data from the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI) trial were reviewed to describe the epidemiology of pericardial involvement in patients treated with or without thrombolysis, and to establish its role as a marker of the extent of myocardial infarction and its prognostic value. In both GISSI-1 (n = 11,806) and 2 (n = 12,381), a specific item regarding presence/absence of clinically detected pericardial involvement was included in the study forms. In GISSI-1, patients with ST elevation and depression at the onset of myocardial infarction were admitted, whereas GISSI-2 included only those with ST elevation. Results of univariate analysis are presented as Mantel-Haenszel-Peto odds ratios with 95% confidence intervals. Cox proportional hazards models were used to assess the independent prognostic significance of pericardial involvement for in-hospital and long-term mortality. The main results indicate that: (1) the incidence of pericardial involvement in patients treated with thrombolytic agents is approximately half of that in the control group (6.7 vs 12.0%); (2) the earlier is the treatment, the lower is the incidence of pericardial involvement; (3) pericardial involvement is strongly associated with infarction size, evaluated by electrocardiograms, creatine kinase peak and echo assessments; and (4) pericardial involvement is associated with a higher long-term mortality, but is not an independent prognostic factor (RR 1.02; 95% confidence interval 0.82-1.26). Pericardial involvement is a reliable bedside, cost-free marker of myocardial infarction size and poorer outcome. Because it may elude detection owing to its transitory and often short duration, it should be given greater attention.
 ...
PMID:Comparison of frequency, diagnostic and prognostic significance of pericardial involvement in acute myocardial infarction treated with and without thrombolytics. Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI). 851 80

The amount of creatine kinase (CK) release (percent of releasable CK) and the amount of irreversibly injured cardiomyocytes evaluated by counting trypan blue stained nuclei (percent of total) was investigated in isolated perfused rat hearts under various conditions: Intermittent contractive depression by low calcium (0.5 mM) and by administration of BDM (10 mM) as well as by anoxia/reoxygenation. For comparison severe injury induced by calcium paradox was also studied. CK release amounted to 0.5% to 3% (controls 15 to 105 min) and to 3 to 5% for the interventions and about 40% for calcium paradox. Irreversibly injured myocytes amounted to 0.1 to 0.3% and 0.3 to 0.5% respectively and to about 40% in calcium paradox. Thus, the percentage of enzyme release exceeded the percentage of irreversibly injured cells by more than one order of magnitude under all experimental conditions, including controls, except for calcium paradox where the percentages were the same. We conclude that cytosolic enzymes can be released to substantial amounts without irreversible injury of cardiomyocytes under various conditions, and only with severe membrane lesions (Ca paradox) enzyme release reflects irreversibly injury.
 ...
PMID:Is enzyme release a sign of irreversible injury of cardiomyocytes? 863 7

To analyze the paradox of acute myocardial infarction (AMI) with an initially normal electrocardiogram (ECG), we reviewed the records of 732 patients discharged with a final diagnosis of AMI over a 2-year period. Twenty-one patient were identified whose initial ECG was normal and who underwent coronary arteriography during the index hospitalization. According to the ECG evolution, three distinct groups were identified: Group 1: those who subsequently developed ST elevation or Q waves (n = 7), Group 2: those who developed ST depression or T-wave inversion (n = 8), and Group 3: those whose ECG remained normal ( n = 6). Peak creatine kinase (CK), timing of the first ECG change, life-threatening complications, and location of the infarct-related coronary lesion were recorded. Infarct-related coronary lesions were also classified into those in a major coronary trunk versus those in secondary branches. The incidence of AMI with a normal ECG was 3.7%. There was no difference in the frequency of coronary artery involvement in the groups studied: left anterior descending (33%), right coronary artery (38%), and circumflex (28%). All ECG changes developed within the first 48 h of hospitalization; 17 +/- 15 in Group 1, and 24 +/- 12 h in Group 2. All six patients who had a persistently normal ECG (Group 3) had lesions in branch vessels (p < 0.05 when compared with Group 1 plus Group 2). Patients who developed ST elevation or Q waves (Group 1) always had a major artery trunk involved (p < 0.05 when compared with Group 2 plus Group 3). Patients in Group 3 had less myocardial damage and fewer complications compared with the other two groups. Myocardial infarction with an initial normal ECG is uncommon and may result from involvement of any of the three coronary arteries. Electrocardiographic evolution usually occurs within the first 48 h of hospitalization. Patients whose ECGs remain normal appear to have culprit lesions in coronary branches, smaller infarctions, and fewer in-hospital complications.
 ...
PMID:Myocardial infarction with an initially normal electrocardiogram--angiographic findings. 878

Rats were given a 200 mg/kg body weight daily dose of alpha-tocopherol by i.p. injection for 15 days. This resulted in elevated levels of glutathione in both liver and brain, and in a reduced hepatic rate of generation of reactive oxygen species. The depression of hepatic and cerebral glutathione levels in ethanol-consuming rats was prevented by simultaneous treatment with alpha-tocopherol. Other putative indices of hepatic pro-oxidant events, namely levels of mixed function oxidase and proteolytic activity, were elevated by alpha-tocopherol both in the presence and absence of ethanol. In addition, levels of enzymes especially susceptible to oxidative degradation, glutamine synthetase and creatine kinase, were depressed in the liver following treatment with ethanol or alpha-tocopherol. Parameters rapidly responsive to oxidative changes revealed the antioxidant property of alpha-tocopherol, while protein-based indices reflecting more extended events suggested a pro-oxidant effect of this vitamin. Results suggest that high levels of alpha-tocopherol can simultaneously lead to a more reduced intracellular environment and yet to localized evidence of enhanced oxidative events.
 ...
PMID:Prevention of ethanol-induced changes in reactive oxygen parameters by alpha-tocopherol. 887 90

We investigated the role of polymorphonuclear leukocytes (PMNLs) in cardiac depression and cytotoxicity during hemorrhagic shock and reinfusion. The dogs were assigned to four groups: I (sham), 4 h duration; II, 2 h of shock followed by reinfusion for 2 h; III, shock and reinfusion in neutrophils depleted with immune serum; IV, same as III but pretreated with nonimmune serum. Cardiac function and contractility were depressed during shock while plasma creatine kinase (CK), and CK-MB increased. Reinfusion tended to return hemodynamic parameters towards control values while oxygen free radical producing activity of PMNLs, plasma CK, and CK-MB increased further. Cardiac malondialdehyde (lipid peroxidation product) and superoxide dismutase activity were higher while left ventricular chemiluminescence was lower in group II as compared to group I. Despite the increase in the antioxidant reserve and antioxidant enzymes, there was oxidative damage. PMNL depletion attenuated the deleterious effects of shock and reinfusion on the hemodynamic and biochemical parameters. The changes in group IV were similar to those in group II. These results suggest that PMNLs may partly be involved in the deterioration of cardiac function, and contractility and cellular injury during hemorrhagic shock and reinfusion.
 ...
PMID:Role of polymorphonuclear leukocytes in cardiovascular depression and cellular injury in hemorrhagic shock and reinfusion. 889 64

The effects of agents modulating the cytoskeleton, taxol (microtubuli stabilizing), vinblastine (microtubuli destabilizing) and cytochalasin D (actin destabilizing) (10(-6) M each) on enzyme and ATP release as well as on irreversible cell injury were investigated in isolated perfused hypoxic and reoxygenated rat hearts. Enzyme (creatine kinase (CK)) and ATP concentration were assayed in the interstitial transudate and venous effluent. Irreversible cell injury was determined from trypan blue uptake and nuclear staining (NS) of cardiomyocytes in histologic sections. ATP release from nonneuronal cells was only detectable in the interstitial transudate and was not significantly altered by the agents. In controls total CK release (about 4% of total CK) exceeded the percentage of irreversibly injured cells by a factor of 8. Taxol and cytochalasin D abolished the hypoxia/reoxygenation induced interstitial CK release and reduced total CK release to a highly significant extent. The percentage of irreversible injured cells was even more diminished by these agents resulting in a ratio of CK/NS of 40. The effect of cytochalasin D apparently is the consequence of decreased contractile performance as shown by analogous depression by butonedione monoxine (BDM), whereas contractile activity was not altered by taxol. Vinblastine had no influence on CK release but increased the number of irreversibly injured cells significantly. In conclusion, cytoskeletal elements apparently participate in the hypoxia/reoxygenation induced process of release of cytosolic enzymes (CK) and irreversible injury in a different way and extent. Taxol exhibits a cytoprotective effect in isolated perfused rat hearts as evaluated by the extent of enzyme release and irreversible cell injury.
 ...
PMID:Relation between enzyme release and irreversible cell injury of the heart under the influence of cytoskeleton modulating agents. 954 Aug 43

A 13-year-old mentally retarded boy suffered from repeated vomiting attacks since infancy. Each episode lasted 2 to 10 days, and was precipitated by respiratory infection, exercise or stress. During an attack he became irritated, agitated and amnesic, but did not have headaches or seizures. Associated findings were transient elevation of serum creatine kinase (CK) (331-3381 IU/l), and of plasma ACTH and cortisol. The raised CK level was the result of muscle hypertonicity. Ictal EEGs showed delta activity in the front-temporal areas, and inter-ictal IMP-SPECT revealed hypoperfusion in both temporal regions. Unlike the periodic ACTH-ADH discharge syndrome, neither hypertension nor depression developed. These attacks were diagnosed as a migraine equivalent and were suppressed with phenytoin. From the EEG and SPECT findings, we concluded that the vomiting and behavioural changes were related to the paroxysmal vascular abnormality in the temporal regions, but it was not easy to make the distinction between migraine and focal epilepsy. Before a diagnosis of the periodic ACTH-ADH discharge syndrome is made, the possibility of migraine equivalent should be considered.
 ...
PMID:Cyclic vomiting and elevation of creatine kinase associated with bitemporal hypoperfusion and EEG abnormalities: a migraine equivalent? 962 97

To study the mechanism of the protective effect of gamma-glutamylcysteine ethyl ester, mitochondrial creatine kinase activity of rat heart was measured. Gamma-glutamylcysteine ethyl ester had a protective effect against the depression of creatine kinase activity induced by xanthine + xanthine oxidase or hydrogen peroxide. Gamma-glutamylcysteine ethyl ester also prevented the depression of creatine kinase activity induced by N-ethylmaleimide. It is suggested that the protective effect of gamma-glutamylcysteine ethyl ester is related to oxygen free radicals or to reduction of the sulfhydryl groups of the enzyme which were previously oxidized by oxygen free radicals.
 ...
PMID:Effects of gamma-glutamylcysteine ethyl ester on heart mitochondrial creatine kinase activity: involvement of sulfhydryl groups. 966 7

The present study compares the on-site interpretation of an admission electrocardiogram (ECG) with core laboratory results in a large, multicenter trial of 516 patients diagnosed with unstable angina pectoris or non-Q-wave myocardial infarction. The local investigators evaluated the admission ECG regarding ST-T changes before the ECGs were sent to the core laboratory for blinded interpretation. The strength of agreement between the observations was described by kappa statistics. There was a poor agreement regarding identification of ST-segment elevation, with 17 patients identified by the local investigator versus 92 by the core laboratory (kappa = 0.05). There was a fair agreement on ST-segment depression with 158 patients diagnosed on-site versus 64 by the core laboratory (kappa = 0.38). Identification of T-wave inversion demonstrated good agreement with 306 patients diagnosed on-site versus 280 by the core laboratory (kappa = 0.63). A moderate agreement regarding identification of a normal ECG was found with 101 patients on-site versus 135 in the core laboratory (kappa = 0.42). Independent variables, including peak creatine kinase-MB and 30-day outcome, were more closely related to core laboratory results than the local investigator's interpretation of the admission ECG. Thus, in the present study, considerable differences were demonstrated between the on-site interpretation of the admission ECG and the blinded evaluation performed in the core laboratory regarding relatively simple electrocardiographic variables. The results suggest that more widespread use of independent evaluation of clinical data should be incorporated in future clinical trials.
 ...
PMID:Differences between local investigator and core laboratory interpretation of the admission electrocardiogram in patients with unstable angina pectoris or non-Q-wave myocardial infarction (a Thrombin Inhibition in Myocardial Ischemia [TRIM] substudy). 967 Oct 9


<< Previous 1 2 3 4 5 6 7 8 9 10