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Biomedical subjects

J M Scott

Publications and source records attributed to J M Scott.

At least 217 records · Page 12Linked to original sources
PubMed1973

The reproducibility and use of the tritiated folic acid urinary excretion test as a measure of folate absorption in clinical practice: effect of methotrexate on absorption of folic acid.

Investigations into the standardization and reproducibility of the urinary excretion method for determining the absorption of tritiated folic acid were carried out. By proper timing of tissue-loading doses of folic acid a clear difference between the percentage excretion ranges of normal and coeliac subjects was obtained. In addition conditions were found whereby the procedure could be repeated on an individual up to four times with reproducible results. Methotrexate in pharmacological amounts was found to have no inhibitory effect on the human intestinal absorption of a small oral dose (300 mug) of folic acid as determined by this method. This indicates that reduction of folic acid is not necessary for its absorption in man.

Administration, Oral↗
PubMed1973

Glucose utilization and production by the dog kidney in vivo in metabolic acidosis and alkalosis.

Using D-[1-(14)C]glucose as a tracer, renal glucose utilization and production was measured in chronic metabolic acidosis and alkalosis in dog kidney in vivo. In six experiments in acidosis, mean total renal glucose production was 4.447+/-1.655 SE mumol/min and glucose utilization was 4.187+/-0.576 SE mumol/min. In five alkalotic experiments it was found that mean total glucose production was 12.227+/-2.026 SE mumol/min and glucose utilization was 18.186+/-2.054 SE mumol/min. Renal glucose utilization and production are therefore significantly higher in alkalosis than in acidosis in vivo. Since glucose production is maximal under conditions when glutamine extraction is minimal (i.e. alkalosis), it is apparent that in alkalosis glutamine is not a major precursor of glucose.

Acidosis↗
PubMed1972

Folate metabolism in Streptococcus faecalis.

The possibility that the inability of Streptococcus faecalis to utilize 5-methyltetrahydropteroylglutamate or pteroyltriglutamate might be due to permeability was investigated. Whereas the former was taken up by S. faecalis cells growing on pteroylglutamic acid, the latter was not. No subsequent conversion of the 5-methyltetrahydropteroylglutamate took place and accumulation, which was against a considerable concentration gradient, was inhibited by fluoride. It would thus appear to be an active process.

Biological Transport, Active↗
PubMed1972

The effect of phenytoin on the absorption of synthetic folic acid polyglutamate.

The absorption of synthetic pteroyltriglutamate has been measured in nine normal students with and without the anticonvulsant drug phenytoin. It has been shown that phenytoin has no effect on the absorption of this folate polyglutamate. The reasons are discussed for the disparity between this result and those reported in the literature when folate polyglutamates derived from yeast were used.

Adult↗