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J S Moshides

Publications and source records attributed to J S Moshides.

7 recordsLinked to original sources
PubMed1988

Enzymatic determination of high density lipoprotein phospholipid using a sensitive reagent and a Cobas Bio Centrifugal Analyzer.

A sensitive enzymatic method for the measurement of high density lipoprotein choline-containing phospholipids (HDL-pc) was adapted to a Cobas Bio Centrifugal Analyzer. The Boehringer Mannheim phospholipase D/choline oxidase/peroxidase reagent was modified by the inclusion of 2,4,6,-tribromo-3-hydroxybenzoic acid (TBHBA) which reacts with hydrogen peroxide and 4-aminophenazone to produce a quinone-imine dye with a fourfold greater molar absorption than that produced with phenol. The method has been developed for the determination of HDL fractions isolated with polyethylene glycol 6000, for which a reagent of high sensitivity is required. The method is linear to 5.5 mmol/l of HDL-pc and the CVs for within-run and day-to-day imprecision were less than 3.5%. Correlation of HDL cholesterol (HDL-c) with HDL-pc values in 200 healthy subjects was good (r = 0.9024). The mean (+/- SD) HDL-pc value for men was 1.12 (+/- 0.26) and for women, 1.34 (+/- 0.29) mmol/l. The assay is inexpensive and large numbers of specimens can be processed rapidly and conveniently.

Bromobenzoates↗
PubMed1988

Enzymic determination of the free cholesterol fraction of high-density lipoprotein in plasma with use of 2,4,6-tribromo-3-hydroxybenzoic acid.

A highly sensitive enzymic colorimetric reagent is described for determination of the free cholesterol fraction of high-density lipoprotein (HDL), which represents about 20% of the total cholesterol content of this lipoprotein. For greater sensitivity with respect to cholesterol, I used 2,4,6-tribromo-3-hydroxybenzoic acid instead of phenol in the cholesterol oxidase/peroxidase/4-aminoantipyrine reagent system. This allows determination of the free cholesterol fraction of HDL isolates prepared with polyethylene glycol 6000, a method for precipitating beta-lipoprotein that involves a twofold dilution of plasma. The reagent, adapted for use with a Cobas-Bio centrifugal analyzer, results in between-run and within-run CVs of less than 3% and a linearity to at least 400 mg of HDL free cholesterol per liter. Comparison with results by Trinder's cholesterol method, which measures cholest-4-en-3-one at 232 nm, showed good correlation (r = 0.9829, slope 1.0001, and y-intercept +2.4797 mg/L). With the manual procedure for HDL free cholesterol, between-batch and within-batch CVs were less than 5%, and results correlated well with those by the automated method (r = 0.9975, slope 0.9839, and y-intercept +2.4327 mg/L). The mean (and SD) HDL free cholesterol for 123 men was 96.8 (30.6) mg/L and for 122 women 136.4 (36.8) mg/L, indicating a distinct sex-related difference, similar to that found for HDL total cholesterol. HDL free cholesterol in plasma may therefore be a potential new predictor of coronary heart disease.

Adult↗
PubMed1987

Improved method for determination of high density lipoprotein cholesterol using a sensitive reagent and a centrifugal analyzer.

Enzymic measurement of high density lipoprotein cholesterol (HDL-c) using a sensitive reagent and a centrifugal analyser is described. The Boehringer Mannheim cholesterol esterase/oxidase reagent has been modified by the inclusion of 2,4,6-tri-bromo-3-hydroxybenzoic acid (TBHBA) which reacts with hydrogen peroxide and the 4-aminophenazone/peroxidase system to produce a quinone-imine dye with a four-fold greater molar absorptivity than that produced with phenol. The resulting reagent system has been developed for use with a centrifugal analyzer for the determination of plasma HDL fractions isolated with polyethylene glycol 6000, for which a reagent of high sensitivity is required. The method is linear to 4 mmol/l of HDL-c and between-run and within-run CVs ranged from 1.01-2.54%. Reagent costs are currently $US 0.12 per test and large numbers of assay samples can be processed rapidly and conveniently. The mean (+/- SD) HDL-c value for men was 1.09 (+/- 0.33) and for women, 1.35 (+/- 0.37) mmol/l.

Centrifugation↗
PubMed1987

Kinetic enzymatic method for automated determination of HDL cholesterol in plasma.

A sensitive fixed-time kinetic enzymatic method for the measurement of high density lipoprotein cholesterol is described, as adapted for the Cobas Bio centrifugal analyser (Hoffmann LaRoche). The Boehringer Mannheim cholesterol esterase/cholesterol oxidase/peroxidase/3,4-dichlorophenol kinetic reagent was modified by the inclusion of 2,4,6-tribromo-3-hydroxybenzoic acid which reacts with hydrogen peroxide and 4-aminophenazone to produce a quinone-imine dye with a greater molar absorptivity than that produced with phenol. The method has been developed for the determination of HDL fractions isolated with polyethylene glycol 6000, for which a reagent of high sensitivity is required. The method is linear to at least 3.88 mmol/l of HDL cholesterol and the coefficients of variation for within-run and day-to-day precision were less than 3.0%. Correlation of the kinetic HDL cholesterol method with an equilibrium method was good (R = 0.9980). The assay is rapid, inexpensive and large numbers of specimens can be processed conveniently.

Autoanalysis↗
PubMedDate not supplied

High density lipoprotein free cholesterol and other lipids in coronary heart disease.

The cholesterol and choline-containing phospholipid fractions of high density lipoproteins (HDL) were determined in healthy males and in male patients with coronary heart disease (CHD) to ascertain which HDL parameter or combined parameters possess the greatest discriminative power. The free cholesterol fraction (HDL-fc) was found to be the most significant discriminator between controls and males with CHD, the mean levels (+/- SEM) being 6.6 (+/- 0.9) and 4.4 (+/- 0.6) mg/dl, respectively. Classification of CHD patients and controls using one-variable discriminant function analysis (DFA) yielded an error rate of 27% for plasma HDL-fc. Two-variable DFA using both the HDL esterified cholesterol levels and the HDL-fc levels of controls and patients reduced the error rate to 11%. The results obtained in this study indicate a possible role for HDL-fc as a predictor of CHD risk.

Adult↗