Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Measurements of alanine aminotransferase and aspartate aminotransferase with the SMAC were evaluated for correlation with the ABA-100, precision, linearity, and carryover. We assayed 200 specimens with normal and abnormal aminotransferase activities with both the SMAC (y) and the ABA-100 (X). Linear regression analysis of the data yielded the following: alanine aminotransferase (r = 0.9732, y = 0.96x + 3.8); and aspartate aminotransferase (r = 0.9892, y = 0.90x + 2.1). Both aminotransferases demonstrated acceptable intra- and inter-assay variations with the SMAC and ABA-100. With the SMAC the upper limit of linearity for alanine aminotransferase was 350 U/L; that for asparate aminotransferase was 450 U/L. Carryover studies for SMAC indicate that specimens immediately following specimens with alanine aminotransferase activities greater 400 U/L and (or) aspartate aminotransferase activities greater than 500 U/L should be re-analyzed.
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PMID:Alanine aminotransferase and aspartate aminotransferase measurements with two automated analyzers, SMAC and the ABA-100, compared. 43 50

Laboratories participating in the College of American Pathologists Enzyme Survey (ES) and Comprehensive Chemistry Survey used diverse methods for the same analyte, resulting in a considerable range of values for the commonly performed enzyme measurements. Nevertheless, with the techniques developed for the ES, both the short-term (within-mailing) and long-term (between-mailings) coefficients of variation (CVs) can be determined. The ten-year experience of the ES has shown improvement in the short-term CV; however, long-term stability of enzyme testing requires more effort on the part of the instrument and reagent suppliers and participating laboratories. A reference material with an International Federation of Clinical Chemistry-established aspartate aminotransferase value, National Bureau of Standards RM 8430, is now available and was sent to three large peer groups as part of a special study. Correction of the results to the RM 8430 aspartate aminotransferase value resulted in reducing the range of data from peers using the duPont aca but not from those using the American Monitor KDA or Technicon SMAC. Based on our experience with the ES, goals of 5% for the short-term CV and 10% for the long-term CV are proposed; they are achievable by most laboratories and meet medical needs for biochemical screening. Fixed criteria for the evaluation of enzyme results appear to be appropriate given the way most enzyme data are used clinically.
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PMID:Proficiency testing of enzymes. Charting the way toward standardization. 335 40

Inexpensive improvements in continuous-flow analytical apparatus can eliminate some perplexing inconsistencies and limitations in the use of the Technicon SMAC instrument for measuring the activity in serum of aspartate aminotransferase (EC 2.6.1.1) in the presence of pyridoxal 5'-phosphate. In addition, a calibration procedure based on values for this enzyme obtained by a modified IFCC method can be used to calibrate both the Technicon SMAC and the Du Pont aca instruments to produce excellent correlation between the two.
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PMID:Determination of serum aspartate aminotransferase with pyridoxal 5'-phosphate in the Technicon SMAC and Du Pont aca compared and correlated with the IFCC recommended method. 396 91

Normal reference ranges for sodium, potassium, urea, creatinine, calcium, phosphate, total protein, albumin, bilirubin, alkaline phosphatase, and aspartate transaminase were determined from 344 fetal and maternal plasma samples between 15 and 38 weeks' gestation. Pure fetal blood was obtained by fetoscopy in the second trimester and in the third trimester by umbilical cord puncture at delivery. All biochemical substances were measured by continuous flow (SMAC, Technicon) except albumin, which was measured by turbidimetry (CobasBio, Roche). The resulting data were analysed on an AMDAHL 470A computer and reference ranges covering 2.5 to 97.5 percentiles were defined. Analysis of variance was performed to examine the overall effect of gestational age on the analytes measured and on the changes in the fetal compartment relative to the mothers'. A paired t test was performed to examine how these biochemical substances in fetal plasma related to maternal plasma from the same pregnancy.
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PMID:Normal reference ranges for biochemical substances relating to renal, hepatic, and bone function in fetal and maternal plasma throughout pregnancy. 398 61

Laboratory values for specimens from a case of intravascular hemolysis showed that hemoglobin was significantly increased and thus could interfere with the determination of other analytes. We studied this problem by adding increasing amounts of purified hemoglobin (to a maximum concentration of 19.3 mg/L) to aliquots of pooled serum samples. The hemoglobin significantly interfered with the determination of only five analytes: albumin, aspartate aminotransferase, direct bilirubin, and total protein on the SMAC, and creatinine on the Astra. We propose that for cases of proven intravascular hemolysis, values for only the analytes not affected by hemoglobin should be reported. We find lactate dehydrogenase activity useful in assessing the components of in vivo hemolysis; the differences between serum and plasma values for potassium, lactate dehydrogenase, and hemoglobin are related to in vitro hemolysis. Criteria for specimen collection and assessment of type of hemolysis are proposed.
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PMID:Hemoglobin interference from in vivo hemolysis. 402 7

We determined normal reference values from data on sera of 2099 outpatient children (ages one week to 14 years) at our institution. Using a continuous-flow instrument (SMAC, Technicon), we determined the following analytes in each serum sample: glucose, creatinine, uric acid, inorganic phosphorus, sodium, potassium, chloride, total CO2, iron, cholesterol, triglycerides, total protein, albumin, total bilirubin, creatine kinase, lactate dehydrogenase, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and calcium. The resulting data were coded and subsequently processed in an IBM 370 computer, and the reference values (3rd and 97th percentiles) were defined for each analyte. A two-way analysis of variance was also done to determine the influence of age and sex on results of these 20 biochemical tests.
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PMID:Normal reference-intervals for 20 biochemical variables in healthy infants, children, and adolescents. 669 87

The chemical measurements on our Technicon SMAC of lipemic sera before and after clearing lipemia by ultracentrifugation showed that uric acid, creatinine, carbon dioxide, calcium, phosphorus, potassium, and alkaline phosphatase were not affected significantly by lipemia, whereas sodium, urea, glucose, chloride and total protein showed small but significant increases with averages of less than 1.9 percent. Albumin showed a significant decrease of 1.2 percent. In contrast, the results for the enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) showed striking differences between pre- and post-centrifuged sera in a number of specimens. With lactate dehydrogenase, thirty-two of fifty specimens registered an increase in activity while with the aminotransferases, thirty-five and forty-one out of fifty specimens showed a decrease in aspartate aminotransferase and alanine aminotransferase activities, respectively. Although much of the lipemic interference can be explained by the volume displacement of serum by lipids or by interference by lipemia with colorimetry, the anomalous effects observed with the enzymes indicate the possibility of other, as yet, undetermined factor(s).
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PMID:The effect of hyperlipidemia on Technicon SMAC measurements. 712 23

The method for continuous-flow assay of aspartate aminotransferase with the Technicon SMAC was modified to include preincubation of the serum enzyme with pyridoxal 5'-phosphate, to be consistent with the recommendations of IFCC and the Standards Committee of AACC. Preliminary estimates of the imprecision of the modified method on SMAC gave day-to-day standard deviations of 5.3 U/L at mean of 48 U/L (n = 66) and 6.2 U/L at 155 U/L (n = 61). Added bilirubin, sodium pyruvate, ascorbic acid, and endogenous lipids did not interfere. Comparison of results for 50 samples by this method with those by the manual IFCC method gave y = 1.1113x - 0.3 U/L, Sy/x = 4.4 U/L, and r = 0.997. Similar data are presented for the revised AST method for the DuPont aca discrete analyzer. Clinical data show that AST activities increase by as much as 200% when the serum is preincubated with pyridoxal 5'-phosphate.
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PMID:Preincubation of serum aspartate aminotransferase with pyridoxal 5'-phosphate in the SMAC: comparison with revised DuPont aca method and recommended IFCC method. 747 32