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Biomedical subjects

C V Byus

Publications and source records attributed to C V Byus.

60 records · Page 4Linked to original sources

Ornithine decarboxylase activity: control by cyclic nucleotides.

Both exposure to cold and administration of aminophylline result in rapid increases in cyclic adenosine monophosphate (cyclic AMP) in the adrenal medulla and adrenal cortex. These increases are followed by dramatic increases in ornithine decarboxylase activity is due to new enzyme systhesis. The data suggest that the decarboxylase activity is regulated by an increase in cyclic AMP.

Adrenal Cortex↗

Recent advances in research on radiofrequency fields and health.

Since the Royal Society of Canada report on potential health risks of radiofrequency (RF) fields from wireless telecommunications in the spring of 1999, there have been several newly published reports on risks associated with the use of mobile phones. This article provides a summary of scientific research on the potential health effects of radiofrequency fields that has been reported since the original Royal Society report was published. This update also discusses several earlier results not included in the original report.

Animals↗

Induction of ornithine decarboxylase in Reuber H35 rat hepatoma cells.

Stimuli known to induce tyrosine aminotransferase in H35 cells were tested relative to their ability to induce ornithine decarboxylase, the initial enzyme in the polyamine biosynthetic pathway. Dibutyryl cyclic AMP (0.5 mM), parachlorophenylthio-cyclic AMP (0.1 mM) and dexamethasone (1 muM) stimulated the activity of ornithine decarboxylase 7- to 8-fold by 5 hr of induction. There was a delay of 1 hr before any increase in enzyme activity was detectable. Insulin administered alone failed to significantly change ornithine decarboxylase activity. The ability of dibutyryl cyclic AMP to elevate ornithine decarboxylase activity was found to be concentration-dependent, and a dose-response relationship very similar to that for the induction of tyrosine aminotransferase by dibutyryl cyclic AMP was observed in these cells. The ability of various 8-substituted cyclic AMP analogues to increase the activity of ornithine decarboxylase was correlated with their ability to activate purified protein kinase.

Animals↗