Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.6.1.1 (aspartate aminotransferase)
21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a study of 1033 consecutive patients with acute myocardial infarction, serum potassium concentrations were determined on admission to hospital and studied with respect to the subsequent occurrence of atrial fibrillation and flutter and of ventricular tachycardia and fibrillation. The study cohort fulfilled the inclusion criteria for the Norwegian timolol trial in which they later took part. In multivariate analysis, with serum potassium concentrations as a continuous variable, age, the presence of ventricular tachycardia and fibrillation, and maximum level of aspartate aminotransferase greater than four times the upper limit of normal were significantly associated with the occurrence of atrial fibrillation and flutter, while serum potassium concentration was not. Serum potassium concentrations and time from onset of the infarction to hospital admission were significantly negatively associated with the occurrence of ventricular tachycardia and fibrillation; while age, cardiomegaly, transient hypotension, pathological Q-waves in the electrocardiogram, atrial fibrillation and flutter, and ventricular premature beats were positively related to these arrhythmias. Thus, there is an independent inverse relationship between serum potassium concentrations and ventricular arrhythmias in acute myocardial infarction.
...
PMID:Serum potassium concentrations are inversely related to ventricular, but not to atrial, arrhythmias in acute myocardial infarction. 370 55

Estimation of enzyme release in plasma requires knowledge of the fractional catabolic rate constant (FCR) for the elimination enzyme activity from plasma. However, the total plasma content of such enzymes usually consists of several isoenzymes with different values of FCR. Thus, the use of a single overall value for FCR may cause error. This problem was studied by determination of the plasma isoenzyme activities of creatine kinase, lactate dehydrogenase, aspartate aminotransferase and alpha-hydroxybutyrate dehydrogenase in patients after cardiac surgery and after acute myocardial infarction. Values of FCR and the cumulative release of activity in plasma are estimated for separate isoenzymes and for total enzyme activity. Results are compared with the enzyme content of myocardium, skeletal muscle and blood cells. It is concluded that isoenzyme separation is not required for the quantitative use of such data. The implications for the validation of enzymatic estimation of cardiac injury are discussed. The results indicate that local inactivation of enzymes after cardiac injury must be limited.
...
PMID:Enzymatic assessment of myocardial injury after infarction or cardiac surgery. Is isoenzyme analysis required? 371 82

The relation of central haemodynamic changes to subsequent mortality and peak enzyme activity was investigated in 190 patients with acute myocardial infarction. The mean delay time from onset of symptoms to the haemodynamic study was 7.2 hours. Major exclusion criteria were heart rate less than 65 beats min-1, systolic blood pressure less than 105 mmHg and lung rales to a distance of greater than 10 cm above the lung bases. Nine patients (4.7%) died within 15 days and 16 patients (8.4%) within 90 days after the infarction. Compared to survivors, non-survivors were characterized by baseline depression of cardiac index, stroke volume index and left ventricular stroke work index, while pulmonary capillary wedge pressure and peripheral resistance were increased. However, a wide overlap between survivors and non-survivors makes the predictive value low in the individual patient. Peak serum aspartate aminotransferase (S-ASAT) activity was weakly related to baseline pulmonary capillary wedge pressure (r = 0.28; P less than 0.001) and stroke volume index (r = -0.22; P less than 0.01). The correlation to pulmonary capillary wedge pressure was only found in anterior (r = 0.34) infarcts. Peak serum lactate dehydrogenase (LD1) was not correlated with baseline haemodynamics.
...
PMID:Central haemodynamics in acute myocardial infarction in relation to mortality and peak enzyme activity. 373 97

In 112 prospectively selected patients suffering from acute myocardial infarction (AMI), the serum CK, CK-MB, LD, HBD, AST and m-AST were determined from the time of admission to hospital and every 12 hours for three days in succession. Sixteen of the enrolled patients died due to complications which arose within the first four days of hospitalization while the rest had a favourable outcome. All enzyme activities were determined at 37 degrees C using routine methods; m-AST was measured using an immunochemical method. The statistical analysis of the results demonstrated that 12 hours after admission, serum m-AST and m-AST/AST ratio were significantly higher in the group of non-survivors compared with patients with a favourable prognosis. No significant differences in CK-MB were observed between survivors and non-survivors during the entire period. True and false positive rates were calculated for these and the other enzymes. An optimum decision level of 34 IU/L was chosen for m-AST and 10% for the m-AST/AST ratio. This gave a percentage of correctly classified patients, after 12 and 24 hours, of 74.9% and 91.9%, respectively. In conclusion, the immunochemical determination of m-AST in patients with AMI seems to be an early prognostic index which is able to distinguish patients with unfavourable outcome.
...
PMID:Prognostic value of mitochondrial aspartate aminotransferase in acute myocardial infarction. 375 2

Serum kinetics of total creatine kinase (CK), CK-MB isoenzyme, aspartate aminotransferase (AST), lactate dehydrogenase (LD) and alpha-hydroxybutyrate dehydrogenase (HBD) activities were studied in twenty patients with acute myocardial infarction randomly assigned to receive either intracoronary urokinase (group A) or conventional (control) therapy (group B). The temporal characteristics of enzyme changes described were the time lag from onset of chest pain until maximum catalytic concentration value, the rate at which enzymes are released into blood, the peak value of the serum enzyme curves and (d) the fractional disappearance rate (Kd) for each enzyme considered. Thrombolytic treatment induced earlier peak times in group A: for CK, 10.8 vs 27.0 h, for CK-MB, 10.4 vs 23.1, for AST, 13.9 vs 31.3, for LD, 24.4 vs 49.1, and for HBD, 20.5 vs 48.5 (for all enzymes, p less than 0.001). The maximal rate of release for the enzymes was at least twofold greater in group A. Enzyme peak activities and Kd were not significantly different between the groups. The most significant discrimination between the two groups was obtained with AST peak time (Hartz overlap index (Oi) = 0.11) and CK-MB peak time (Oi = 0.12).
...
PMID:Serum enzymes in acute myocardial infarction after intracoronary thrombolysis. 376 94

Activities of aspartate aminotransferase (AST) isoenzymes were determined in serial serum samples from 40 cases of acute myocardial infarction, and compared with activities of creatine kinase, CK-MB isoenzyme, lactate dehydrogenase, and alpha-hydroxybutyrate dehydrogenase for temporal changes. Cytosolic (soluble) AST (s-AST) and mitochondrial AST (m-AST) respectively increased 6.6 and 9.0 h after onset of chest pain. The median time at which serum m-AST activity peaked (15.8 U/L, range 6.4-53.5 U/L) was 47.8 h after the onset of infarction, 19.8 h later than the peak s-AST activity (171 U/L, range 53-517 U/L) and m-AST also disappeared from the serum more slowly than s-AST (p less than 0.001). Serum m-AST values were above normal for at least six days after the infarct. The ratio of m-AST to total AST in serum increased after myocardial infarction, being greatest (20%, range 11-32%) on the third day after onset. For individuals, peak activities of s-AST correlated well with total CK (r = 0.91) and CK-MB (r = 0.86) peak activities, indicating that s-AST also reflects the infarct size. However, m-AST correlated poorly with the enzymes commonly used in infarct diagnosis; it apparently provides different biological information.
...
PMID:Activity of serum aspartate aminotransferase isoenzymes in patients with acute myocardial infarction. 380 98

The serum activities of aspartate aminotransferase, lactate dehydrogenase, creatine kinase and estimated creatine kinase isoenzyme MB (CK-B) were investigated in 12 patients before and after revascularization of ischaemic lower extremities. All patients suffered from sudden lower limb arterial occlusion and underwent embolectomy through a small arteriotomy in the groin. The median serum activity of all four enzymes was elevated before surgery and further increased during the first 24-48 h after revascularization. Median serum activity of aspartate aminotransferase, creatine kinase and lactate dehydrogenase were continuously elevated 7 days after the operation. A high relative CK-B activity coincided in one patient with the development of electrocardiographic evidence of acute myocardial infarction. It is concluded that any of these four enzymes should be used with caution in the diagnosis of acute myocardial infarction before, during or after operation in patients who have sustained prolonged ischaemia of the lower extremities.
...
PMID:Evaluation of the usefulness of enzymatic diagnosis of myocardial infarction in patients with acute arterial occlusion of the lower extremities. 382 74

Serum (S) enzyme activity of aspartate aminotransferase (ASAT, E.C. 2.6.1.1.), heat stable lactate dehydrogenase (LD, E.C. 1.1.1.27.), creatine kinase (CK, E.C. 2.7.3.2.) and CK-B subunit and the respective standard electrocardiograms (ECG) were compared in 463 patients with suspected acute myocardial infarction (MI) in order to evaluate sensitivity and specificity. Serum ASAT was analysed daily for 3 days, S-heat stable LD every 12 h for 48-108 h, S-CK and S-CK-B every 6 h for 48 h and ECG once daily for 3 days. All four enzymes had a high sensitivity, varying from 99% for LD to 97% for CK-B. The highest specificity was observed for CK-B and CK (98%) as compared with heat stable LD (91%) and ASAT (74%). Standard ECG showed a high specificity (96%) and a low sensitivity (80%).
...
PMID:The diagnostic value of different enzymes and standard ECG in acute myocardial infarction. 389 41

The maximum serum activity for aspartate aminotransferase (s-ASAT) during the first 3 days was recorded in 5,507 patients with suspected or definite acute myocardial infarction. The s-ASAT activity was corrected for the normal range from each center. The median s-ASAT activity was 4.9 arbitrary units in the placebo group versus 4.6 arbitrary units in the metoprolol group (p = 0.072). Univariate analyses indicated that the delay time between onset of symptoms and randomization and sympathetic activity at entry significantly influenced the effect of metoprolol. A similar decrease in serum enzyme activity after metoprolol treatment was observed independent of signs of infarct localization on the entry electrocardiogram.
...
PMID:Metoprolol in acute myocardial infarction. Enzymatic estimation of infarct size. The MIAMI Trial Research Group. 390 91

Sixty patients with a first acute myocardial infarction and no current treatment with cardioactive drugs were included in a prospective study of the relationship between serum potassium concentration and the early occurrence of ventricular tachycardia and premature ventricular contractions (PVCs). Serum potassium level (range 2.5 to 5 mmol/liter) was estimated 3.8 +/- 2.5 hr (mean +/- SD) after the onset of the infarction, and Holter monitoring was performed during the subsequent 12 hr. In multivariate analysis, serum potassium level was negatively and age positively related to ventricular tachycardia. Among the subclasses of PVCs (frequent unifocal, multifocal, couplets, bigeminy), serum potassium concentration was negatively related to the frequent unifocal subclass; hypertension was related to couplets and to the presence of any of the subclasses, and serum aspartate aminotransferase concentration was related to multifocal PVCs. Heart failure leading to death was related to all subclasses of PVC. Serum potassium concentration is an independent inverse predictor of the occurrence of ventricular tachycardia and frequent unifocal PVCs early in acute myocardial infarction.
...
PMID:Serum potassium concentration as a risk factor of ventricular arrhythmias early in acute myocardial infarction. 397 35


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

---