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

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

Low turbidity, "clear" enzyme controls commercially produced in three concentrations and conventional human lyophilized control sera, which are more turbid, were evaluated to determine which was superior for quality control purposes. Criteria used to evaluate the controls were: 1) turbidity measurement, 2) daily assays for 30 days to estimate day-to-day precision, and 3) stability of the enzyme assay value for these controls when they were reconstituted and frozen for 0 to 30 days and 0 to 10 days with three aliquots separately prepared and frozen for 0 to 10 days for a total of 30 days. The controls were analyzed for lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, creatine kinase, and alkaline phosphatase activities with the Perkin-Elmer KA 150 enzyme analyzer.
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PMID:The use of "clear" enzyme control materials. 42 91

The effects of three widely spaced levels of bacterial contamination of reagent water on several chemistry, radioimmunoassay, and coagulation procedures were studied. These included determinations of lactate dehydrogenase, creatine kinase, aspartate transaminase, alkaline phosphatase, blood urea nitrogen, total protein, thyroid-stimulating hormone, digoxin, thrombin time, activated partial thromboplastin time, and prothrombin time. Statistical analyses included calculations of means and coefficients of variation, and analysis of variance, as well as correlation coefficients for test results versus logarithm of bacterial contamination. Statistically and clinically significant differences occurred together only for an elevated level of creatine kinase.
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PMID:Effects of bacterial contamination of reagent water on selected laboratory tests. 43 36

The hepatocyte and haematopoietic cell contents of the liver of the foetal guinea pig were measured over the latter half of gestation. Hepatocytes represented about 30% of liver volume at mid-gestation and this increased to 70-80% by term; cell volume remained fairly constant until 5-7 days before term, then more than doubled. Haematopoietic cells represented about 5% of liver volume at mid-gestation and this progressively fell to <1% by term. At 75% of gestation hepatocytes and haematopoietic cells were prepared from perfused foetal livers by collagenase digestion. Enzyme activity of the hepatocyte was, without exception, similar to that of the whole liver. In general, enzyme activity in the haematopoietic cells was similar to that in erythrocytes, with relatively low values for aldolase, glycerol 3-phosphate dehydrogenase, phosphoglycerate mutase, enolase, lactate dehydrogenase, phosphoenolpyruvate carboxykinase, fructose 1,6-bisphosphatase, isocitrate dehydrogenase, ;malic' enzyme, glutamate dehydrogenase and aspartate aminotransferase. The haematopoietic cell contribution to total enzyme activity in the foetal liver was usually much less than 10% and could thus not account for the major changes in hepatic enzyme activity over the latter half of gestation. Hepatocytes contained hexokinase isoenzymes I and III, aldolase isoenzymes A and B and pyruvate kinase isoenzymes 1, 2 and 4. The haematopoietic cells contained hexokinase isoenzyme I and two additional bands of activity with slightly greater mobility, aldolase isoenzyme A and pyruvate kinase isoenzymes 2 and 4.
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PMID:The distribution of enzyme and isoenzyme activities between parenchymal and haematopoietic cells in the liver of the foetal guinea pig. 43 88

Normal values for 13 chemical constituents of plasma were estimated from results for 837 presumably healthy children. Ninety microliters of specimen was analyzed for lactate dehydrogenase, aspartate aminotransferase, alkaline phosphatase, inorganic phosphorus, total calcium, total cholesterol, total proteins, albumin, uric acid, urea nitrogen, alanine aminotransferase, total bilirubin, and glucose. We used two Abbott ABA-100 Bichromatic Analyzers interfaced directly to the ABA Data Management System. For each test age- and sex-related variations were assessed and normal values were estimated for six different age groups.
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PMID:Microchemical analysis for 13 constituents of plasma from healthy children. 43 35

In order to verify the influence of sampling time on blood constituents, populations of supposedly healthy subjects were grouped according to age, sex, deviation from their ideal weight, state of fasting or nonfasting, and time of sampling. Each fasting subject in one group underwent two samplings during the course of a morning: the first at 08.00 and the second between 09.00 and 12.00. In the second group, the first was taken at 13.00, and the second between 14.00 and 16.00. Subjects in the second group had eaten a standard meal of 700 calories at 12.00. Differences between the paired samples from a given individual are discussed with respect to the time of sampling for plasma urea, creatinine, proteins, albumin, calcium, sodium, potassium, cholesterol, uric acid, chloride ions, phosphate, bilirubin, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, creatine phosphokinase, alkaline phosphatase, hemoglobin and erythrocyte and leukocyte counts. Variations due to the time of sampling were large for phosphorus, bilirubin, and leukocyte count.
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PMID:The effect of sex, deviation from ideal weight and sampling time on blood constituents in presumably healthy subjects. 43 75

We measured creatine kinase (EC 2.7.3.2) activity in 1009 serum samples from 538 patients in the intensive-care units of the University of Texas Medical Branch hospitals. Creatine kinase isoenzymes migrating cathodal to skeletal muscle creatine kinase (CK-MM) on cellulose acetate electrophoresis were found in sera from 14 of the 538 patients. Creatine kinase, lactate dehydrogenase (EC 1.1.1.27), aspartate aminotransferase (EC 2.6.1.1), and alanine aminotransferase (EC 2.6.1.2) activities were abnormally increased in these 14 patients. Liver lactate dehydrogenase isoenzyme (LDH5) and cardiac creatine kinase isoenzyme (CK-MB) were abnormally increased in 12 and eight of these patients, respectively. Ten of the 14 patients died during their hospital admission. We believe the creatine kinase isoenzymes that migrated cathodal to skeletal muscle creatine kinase (CK-MM) were of mitochondrial origin.
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PMID:Creatine kinase isoenzymes of mitochondrial origin in human serum. 44 29

In an experimental study, employing anaesthetized dogs, it was investigated whether cellular enzymes from peripheral skeletal muscle get into the circulating blood by diffusion across capillary membranes or by lymphatic transport. In the experimental group 1, the animals were anaesthetized only. The plasma activities of the four enzymes measured--lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, creatine kinase--did not show any mentionable change during a time period of 6 h. In group 2 one hind limb of each animal was moved passively for 1 h. Alanine aminotransferase remained unchanged in plasma, the activities of the three other enzymes increased significantly. In group 3 one hind limb was made hypoxic by clamping the femoral blood vessels for 1 h. No activity changes were observed. When the period of hypoxia was followed by a 1-hour period of passive movement in group 4, the alterations in plasma activities were almost identical to those observed in group 2. In group 5 the experimental procedure was as in group 4, in addition the lymph from the thoracic duct was quantitatively withdrawn. The enzyme activities in plasma revealed a tendency to decrease rather than increase. Lymph flow increased significantly as well as the lymphatic activities of those enzymes which have high intracellular activities in muscle. The results prove, that enzymes from muscle are transported from the interstitial into the intravascular compartment mainly by lymphatic transport. Indications were found that the interruption of blood flow in one hind limb did not result in an enzyme release from muscle cells. It is discussed how changes in lymph flow, occurring during physical exercise for example, affect enzyme activities in plasma.
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PMID:Lymphatic transport of cellular enzymes from muscle into the intravascular compartment. 45 37

To identify the most sensitive screening test for cardiac contusions, a series of 35 patients with blunt chest trauma was evaluated with serial electrocardiograms (ECGs)- creatine phosphokinase isoenzymes, and serum enzymes (serum glutamic-oxaloacetic transaminase, lactic dehydrogenase, and creatine phosphokinase). Twenty of the 35 patients had diagnoses of cardiac contusions by ECG. Three with contusions developed complications. Although isoenzyme elevation was present in most patients sustaining blunt chest trauma, no complications of the injury were seen in patients with elevated enzymes and normal ECGs. The ease of obtaining ECGs and their reliability in identifying patients who will have complications make it the best screening procedure for the diagnosis of cardiac contusions.
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PMID:CPK-MB isoenzume determinations in blunt chest trauma. 45 88

Oxamate, a potent inhibitor of lactate dehydrogenase, is shown also to inhibit aspartate aminotransferase activity, both in human serum and in purified isoenzymes of human origin. The inhibition was competitive with respect to 2-oxoglutarate for both isoenzymes. The apparent Ki was 29 mmol/L for the cytoplasmic enzyme and 17 mmol/L for the mitochondrial enzyme. Noncompetitive inhibition was found between oxamate and aspartate. At saturating concentrations of substrate (2-oxoglutarate greater than or equal to 15 mmol/L, L-aspartate greater than or equal 150 mmol/L) oxamate inhibited the mitochondrial enzyme but had less effect on the cytoplasmic isoenzyme. Oxamate at 40 mmol/L inhibited the enzyme in serum by 11 and 9% in assays containing 2-oxoglutarate at 6.7 and 15 mmol/L, respectively. This concentration of oxamate inhibited enzyme activity in serum by 5% more than did the same concentration of Cl- (itself an inhibitor). Oxamate (less than or equal to 30 mmol/L) had no measurable effect on the stability or activity of porcine malate dehydrogenase. Until the effects of its inhibitory properties are considered, addition of oxamate to suppress lactate dehydrogenase-mediated side reactions in the assay of aspartate aminotransferase cannot be recommended.
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PMID:Measurement of aspartate aminotransferase activity: effects of oxamate. 46 65

The overall performances of several enzyme reagent kits for alkaline phosphatase, creatine kinase, lactic dehydrogenase, and aspartate aminotransferase were evaluated using an ABA-100 Bichromatic Analyzer. Interassay precision using this instrument with commercial reagents compared well with published data for similar analyses performed at university hospitals and referral laboratories. Significantly poorer precision with lower limits of linearity was observed when reagents recommended for use at 30 C were used at 37 C. Significant differences in measured levels of creatine kinase, lactic dehydrogenase, and aspartate aminotransferase due to different lots of expendable cuvettes were found for elevated levels of these enzymes. All kit reagents met manufacturers' claims for stability; however, different absolute levels of lactic dehydrogenase were observed with one kit reagent on successive days. Slight hemolysis affected creatine kinase levels measured with some reagent kits significantly more than others.
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PMID:Evaluation of commercial enzyme reagent kits by use of a semiautomated chemistry analyzer. 47 90


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