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Biomedical subjects

J B Whitfield

Publications and source records attributed to J B Whitfield.

84 records · Page 5Linked to original sources
PubMed1978

Some laboratory correlates of drinking habits.

The effect of drinking habits on the frequency distributions of eight biochemical or haematological test results was studied in 7915 patients attending a multiphasic health testing centre. Increasing incidences of abnormal results with increasing alcohol intake, at levels of alcohol intake habitual for a large proportion of the population, were found for plasma gamma-glutamyl transpeptidase, triglycerides and uric acid, and for erythrocyte mean corpuscular volume. Of four frequently used liver function tests, aspartate aminotransferase, alkaline phosphatase, bilirubin, and albumin, only aspartate aminotransferase was strongly affected by drinking habits. These findings have relevance for the detection of individuals whose drinking habits are harmful to them, and for the interpretation of 'profile' results.

Alcohol Drinking↗
PubMed1978

Estimation of alcohol intake from laboratory results.

Subjects with abnormalities in a number of laboratory tests were shown to have higher than usual probabilities of being heavy drinkers. Quantitative estimates have been made of the probabilities of heavy drinking from the results of the following tests: gamma-glutamyl transpeptidase, mean corpuscular volume, uric acid, triglyceride, and aspartate aminotransferase. In men, but not in women, there was a clear increase in this probability with increasing test results for these five tests, which may prove useful in the detection of individuals who are at risk from their drinking habits.

Alcohol Drinking↗
PubMed1973

Changes in plasma -glutamyl transpeptidase activity associated with alterations in drug metabolism in man.

A significant rise in plasma gamma-glutamyl transpeptidase activity (GGT) was observed on 13 out of 14 occasions on which patients on long-term treatment with the oral anticoagulant warfarin were given amylobarbitone, quinalbarbitone, or phenazone (antipyrine) for 30 days. In 13 of these 14 studies there was evidence that drug administration had stimulated the rate of warfarin metabolism. One patient showed no increase in plasma GGT activity, yet a significantly increased rate of warfarin metabolism, and another patient showed an increase in plasma GGT activity without a change in warfarin metabolism. When alterations in both plasma GGT activity and plasma warfarin concentration occurred together in response to drug administration the changes followed a similar time course, occurring after about one week of drug administration with maximal changes at about 10 or 15 days. Administration of chlordiazepoxide, diazepam, nitrazepam, and methaqualone did not stimulate the rate of warfarin metabolism in four patients studied, but plasma GGT activity increased significantly in two of these four instances. The implications of these observations in the interpretation of plasma GGT activities are discussed.

Acyltransferases↗
PubMed1972

Serum -glytamyl transpeptidase activity in liver disease.

Serum gamma-glutamyl transpeptidase (GGT) activity correlates closely with the activities of alkaline phosphatase (ALP) and 5'-nucleotidase (5NT) in various forms of liver disease. Maximum elevations of all three enzyme activities are observed in diseases which particularly affect the biliary tract. Compared with the other two enzymes GGT is generally increased to a greater extent and is thus the most sensitive indicator of biliary-tract disease, while estimations of serum GGT are more reproducible than those of 5NT. However, a group of patients who had been treated with phenytoin and barbiturates were found to have elevated serum GGT activities without any other evidence of liver disease. The apparent effect of certain drugs on serum GGT activity indicates the need for caution in interpreting the results of this test.

Acyltransferases↗
PubMedDate not supplied

Effects of the protease inhibitor (Pi) polymorphism on alpha-1-antitrypsin concentration and elastase inhibitory capacity in human serum.

The concentration of alpha-1-antitrypsin (AAT) and its elastase inhibitory capacity (EIC) have been investigated in vitro in sera from 1688 healthy Canberra blood donors typed for electrophoretic variants of the protease inhibitor (Pi) locus. Nine Pi alleles were recorded in the sample, of which M1 was found at a frequency of nearly 70% and the other eight were each at frequencies below 15%. As a class, heterozygotes among the three Pi M subtype alleles, M1, M2 and M3, have higher means and lower variances for AAT and EiC than do the three M subtype homozygotes. Among the three homozygotes M1M1 has highest AAT and EIC and among the heterozygotes dominance in M1M2 and M1M3 is towards or beyond the high M1M1 values. Of the six other Pi alleles recorded, two (F and G) have similar values to the M subtypes but the other four (I, N, S and Z) have lower values. The patterns of means and variances in AAT and EIC for the different M subtype genotypes do not support the precise threshold function postulated by Martin and Oakeshott (1983) to relate activity to Darwinian fitness. Nevertheless, several aspects of the results are consistent with a general positive relationship between activity and fitness.

Adolescent↗
PubMedDate not supplied

Meta-analysis of the effects of alcohol dehydrogenase genotype on alcohol dependence and alcoholic liver disease.

The purpose of this paper is to assemble and evaluate existing data on the effect of genetic variation in ADH2 and ADH3 on the risk of alcohol dependence, and on the risk of alcoholic liver disease. Calculations of odds ratios and their confidence limits, and tests for heterogeneity of the results from the available studies, have been performed. It is clear that possession of the ADH2-2 allele decreases the risk of alcohol dependence, but it increases the risk of alcoholic liver disease among alcoholics. ADH3 variation also has significant effects on alcohol dependence, which may be due to linkage to ADH2; the ADH3 effect differs significantly between Asian and European subjects. Therefore ADH genotype has substantial effects on risk of alcohol dependence and alcoholic liver disease, but more work is needed on the generalizability of these findings to non-Asian populations, and on possible mechanisms.

Alcohol Dehydrogenase↗