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Biomedical subjects

M I Bethel

Publications and source records attributed to M I Bethel.

4 recordsLinked to original sources
PubMed1987

A simple blood sample method for measuring oral zinc absorption in clinical practice.

Tracer activity in blood 14 days after the oral ingestion of zinc-65 has been compared with zinc absorption measured by whole-body counting in 10 controls and 25 subjects with Crohn's disease. Highly significant linear correlations (P less than 0.001) were obtained between blood tracer activity and zinc absorption for both the control group (previously reported) and the Crohn's disease group, thus allowing zinc absorption to be predicted from blood tracer activity with an accuracy of +/- 7.1% for the control group, +/- 17.1% for an active Crohn's disease sub-group and +/- 18.0% for a quiescent Crohn's disease sub-group. Relative to the whole-body counting method, the prediction of zinc absorption from blood tracer activity had a sensitivity of approximately 88%, a specificity of approximately 89% and an overall performance accuracy of approximately 88%. Therefore, where whole-body counting facilities are not available, the blood tracer technique for predicting zinc absorption could be a useful alternative.

Administration, Oral↗
PubMed1986

Food iron and lead absorption in humans.

Food iron and lead absorption were measured simultaneously in 28 subjects by extrinsically labeling three consecutive meals with the radioactive tracers, iron 59-sulfate and lead 203-chloride. Absorption was measured directly in all subjects by whole-body counting and indirectly in 15 subjects by assessing subsequent levels of tracer in blood. Iron status of the subjects ranged from iron deficient to replete, thus providing a wide range of iron absorption. Statistically significant positive correlations were obtained between food-iron and lead absorption measured by whole-body counting and also between the tracer levels of iron and lead in the blood. However, the correlation between the absorption of the two elements was not strong, as evidenced by the fact that only 50% of the subjects who hyperabsorbed iron also hyperabsorbed lead.

Administration, Oral↗
PubMed1979

Diet, absorption, and hormone studies in relation to body weight in obstructive airways disease.

Sixteen male patients with stable chronic obstructive airways disease were separated into two groups of eight according to arterial carbon dioxide tensions. Hypercapnia was associated with lower arterial oxygen tensions, higher red cell volume, and increased weight, while normocapnic subjects were decidedly thin. The considerable difference in body weight between the two groups could not be explained by variation in caloric intake, and malabsorption was excluded as a cause of weight loss in the underweight subjects. Serum tri-iodothyronine, thyroxine, cortisol, and oestradiol concentrations were similar and normal in each group, but both groups had significantly low testosterone values as compared with controls, values in the hypercapnic being appreciably lower than in the normocapnic group. The adrenal androgen dehydroepiandrosterone was significantly high in the normocapnic group and low in the hypercapnic group compared with controls. Serum pituitary luteinising and follicle stimulating hormones were normal, but three hypercapnic individuals had high serum prolactin values. Early morning urinary aldosterone values were significantly higher in the hypercapnic than in the normocapnic group. Such hormone comparisons have not previously been made in subjects with chronic obstructive airways disease grouped according to arterial blood gas values, and it is concluded that major alterations in adrenal and testicular function may occur, possibly due to pituitary suppression from hypoxia. Such hormonal changes might in part account for the contrasting alterations in body habitus found in this condition.

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