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Biomedical subjects

H S Fraser

Publications and source records attributed to H S Fraser.

At least 55 records · Page 3Linked to original sources
PubMed1980

Environmental factors affecting paracetamol metabolism in London factory and office workers.

A Paracetamol elimination was measured, using serial saliva samples, in 114 London factory and office workers, 76 Whites and 38 Asian immigrants. 2. Use of social drugs such as alcohol, tobacco and the oral contraceptive varied considerably within the sample, being appreciably greater in White subjects. 3. Paracetamol clearance was 21% slower in Asians than in Whites and half-life 18% longer. The total range of clearance was 1.86--6.78 ml min-1 kg-1. 4. Clearance was slower in women than in men, increased with increasing alcohol intake and cigarett consumption, and was more rapid in those women using the oral contraceptive. The effects of alcohol and the oral contraceptive were also found in White subjects alone. 5 The variables found to correlate independently with paracetamol clearance accounted for only 27% of the total sample variance, however, and are unlikely to be the major determinants of paracetamol elimination in man.

Acetaminophen↗
PubMed1980

Antipyrene clearance in Indian villagers.

1 Antipyrine clearance has been measured using saliva samples in 50 Maharashtrans from a village to the north of Bombay. 2 All subjects were very lean and were also anaemic probably as a result of hookworm infestation. 3 Antipyrine clearance was 36% faster than in White Londoners studied previously and more than twice as fast as in Asian immigrants living in London. 4 Clearance was 25% faster in men than in women but volume of distribution was also greater in men and mean half-lives did not differ significantly between the sexes. 5 There was a negative correlation between antipyrine clearance and haemoglobin concentration. 6 The study has identified geographic differences in antipyrine metabolism which could be clinically important. The role of anaemia merits further study.

Adult↗
PubMed1979

Environmental factors affecting antipyrine metabolism in London factory and office workers.

1 Measurements of antipyrine clearance in saliva have been made in 128 London factory and office workers. 2 Mean antipyrine clearance in 56 Asian immigrants was 40% slower than in 72 White subjects. 3 Although dietary differences existed between the two groups, analysis of their effect independently of race was impossible since all but one of the vegetarians were Asian and the non-vegetarians were nearly all White. 4 In the White subjects, use of the oral contraceptive reduced clearance by 38% in women, while cigarette smoking increase clearance by 38% in men.

Adolescent↗
PubMed1979

Reduction of circulating 25-hydroxyvitamin D by antipyrine.

1 Twenty-four Asian vegetarians had significantly lower 25-hydroxyvitamin D (25-OHD) levels and longer antipyrine half-lives than twenty white non-vegetarians (P less than 0.001). 2 Treatment with oral antipyrine over 4 or 5 weeks in seven vegetarian Asians and five racially different non-vegetarians increased drug oxidation significantly in both groups as measured by a fall in antipyrine half-lives and a rise in serum gamma-glutamyltranspeptidase levels and urinary 6 beta-hydroxycortisol/17-hydroxycorticosteroid ratios. 3 Antipyrine treatment produced a fall in circulating 25-hydroxyvitamin D of around 60% in all subjects in whom pretreatment levels could be measured, independent of race and diet. 4. In the Caucasian non-vegetarian group 1,25 dihidroxyvitamin D levels, the most active metabolite of vitamin D, were also measured and remained unaltered despite a substantial fall in 25-hydroxy substrate. 5 The acute fall in 25-hydroxyvitamin D concentration with a maintained level of 1,25 dihidroxyvitamin D may represent the early changes of drug-induced osteomalacia.

Adult↗
PubMed1979

Contribution of environmental factors to variability in human drug metabolism.

Drug metabolism in 96 London factory and office workers has been studied after simultaneous single doses of antipyrine (phenazone) and paracetamol (acetaminophen). Metabolic clearance of both drugs was significantly greater in subjects eating meat more than once a week than in those who ate meat less frequently. The precise contribution of diet could not be clearly defined since 90% of "meat-eaters" were European while all except one of the "vegetarians" were Asian. Clearance of both drugs increased with both alcohol and cigarette consumption. Regular intake of coffee and/or tea had a similar effect but, in the case of paracetamol, this did not attain statistical significance. Antipyrine clearance was lower among women who took the oral contraceptive pill than among those who did not, while paracetamol clearance was not significantly different. These findings may have implications for the use of drugs which are administered regularly in order to achieve steady-state plasma and tissue concentrations.

Adolescent↗
PubMed1979

Ganja (marijuana)

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Cannabis↗
PubMed1977

Accentuation of ethanol-induced fatty liver by phenobarbitone.

1. Four groups of rats received a liquid formula diet, given alone (control), or supplemented with either ethanol or phenobarbitone, or both together. 2. The ethanol-treated group showed a fall in plasma triglyceride and a rise in liver triglyceride, as compared with the control rats. 3. The phenobarbitone-treated group showed a marked rise in plasma triglyceride but not in liver triglyceride. 4. The group receiving both ethanol and phenobarbitone also showed a rise in plasma triglyceride, but this was accompanied by a striking increase in liver triglyceride. 5. These results suggest that ethanol and phenobarbitone each stimulate triglyceride synthesis but that in addition ethanol has an inhibitory effect on hepatic triglyceride secretion.

Animals↗
PubMed1976

Factors affecting antipyrine metabolism in West African villagers.

Saliva half-life of antipyrine was studied in 49 healthy Gambians between 20 and 60 yr of age of whom 27 were male (mean age, 44.5) and 22 female (mean age, 39.1). Body wieght, height, ponderal index, albumin, and hemoglobin were moderately reduced compared to accepted normal values. Antipyrine half-life was 13.6 +/- 0.58 (SEM) hr. Multiple regression analysis showed that sex, cola nut consumption, hemoglobin in women, and height in men were statiscally significant independent predictors of antipyrine half-life. Half-life was shorter in women, decreased with an increase in height in men, and was prolonged by cola nut consumption. Half-life in women increased with hemoglobin. These factors explained 36% of the variation and suggest that geographic differences in the environment could be important in drug metabolism in man.

Adult↗
PubMed1976

Assessment of antipyrine kinetics by measurement in saliva.

The half-life of antipyrine has been estimated from saliva samples in ten subjects by a gas chromatographic method. Half-life, apparent volume of distribution and total body clearance estimated from saliva and plasma concentrations of antipyrine are not significantly different. The concentration of antipyrine in saliva is independent of flow rate within the range expected in healthy subjects in response to mechanical and sapid stimuli. Antipyrine estimation in saliva could facilitate many areas of phaamacokinetic research limited by the difficulty of obtaining serial plasma samples.

Adult↗