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G V Purcell

Publications and source records attributed to G V Purcell.

3 recordsLinked to original sources

Alanine aminotransferase and aspartate aminotransferase measurements with two automated analyzers, SMAC and the ABA-100, compared.

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.

Alanine Transaminase↗

Evaluation of the BMC glucose oxidase/peroxidase-4-aminophenazone-phenol procedure for glucose as adapted to the Technicon SMAC.

We evaluated the analytical performance of Trinder's glucose oxidase (EC 1.1.3.4)/peroxidase (EC 1.11.1.7) 4-aminophenazone-phenol method for the quantification of serum glucose as adapted to the Technicon SMAC. Our results correlated well with those by the routine SMAC glucose oxidase/peroxidase 3-methyl-2-benzothiazolinone hydrazone-N,N-dimethylaniline method (y = 1.02x - 49.4; r = 0.99) and the glucose oxidase oxygen-rate method (y = 0.99x + 14; r = 0.99) with the Beckman Glucose Analyzer. Sample-to-sample interaction was less than 1%. Ascorbic acid or uric acid in concentrations as high as 200 mg/L were without demonstrable effect on results for glucose. Intra- and inter-assay precisions (CV) were 1.6 and 2.3%, respectively. The upper limit of linearity was about 5 g/L. Adaptation of the Trinder method for glucose to the SMAC is simple and provides an analytically acceptable and economical alternative to the methods ordinarily used with the SMAC.

Adolescent↗

Hydration of macromolecules.

Frozen protein and nucleic acid solutions at -35 degrees C show relatively narrow (100 milligauss) proton nuclear magnetic resonance signals which are assignable to water that is sufficiently mobile to reduce the dipolar broadening normally associated with solids. Hydration was found to be 0.3 to 0.5 gram of water per gram of protein. Nucleic acids are three to five times as hydrated as proteins. Conformational changes in solution produce detectable changes in linewidth or amount of "bound" water, or both. The very fact that the water signals can be observed by high resolution nuclear magnetic resonance suggests that it is not "ice-like" in any literal sense, although it is clearly less mobile than liquid water at the same temperature. A simple model is described which considers both surface hydration and trapped water.

Chemical Phenomena↗