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Biomedical subjects

R E Thomas

Publications and source records attributed to R E Thomas.

At least 73 records · Page 4Linked to original sources

Inotropic activity of digitoxigenin glucoside and related glycosides.

The cardiovascular effects of digitoxigenin glucoside and two derivatives, digitoxigenin glucoside tetraacetate and 4',6'-isopropylidene digitoxigenin glucoside were studied in pentobarbital-anaesthetized dogs. Digoxin (0.112 mumol/kg) and digitoxigenin glucoside (0.056 mumol/kg) produced similar increases in myocardial contractility, although digitoxigenin glucoside was faster in onset of action and had a shorter duration of action. Digitoxigenin glucoside caused a significantly greater increase in blood pressure than digoxin. Digitoxigenin glucoside tetraacetate (0.056 mumol/kg) and isopropylidene digitoxigenin glucoside (0.112 mumol/kg) also increased myocardial contractility. Time to peak effect and duration of action were similar to those of digitoxigenin glucoside. The tetraacetate derivative of digitoxigenin glucoside was less hypertensive than the parent compound. The results suggest that the rapid onset and short duration of effect are a function of the glucose moiety. The rapid onset and, what appears to be, a reduced tendency to accumulate may confer clinical potential for these analogues.

Animals↗

Effect of water-soluble fraction of Cook Inlet crude oil on swimming performance and plasma cortisol in juvenile coho salmon (Oncorhynchus kisutch).

Swimming performance of juvenile coho salmon decreased and plasma cortisol increased, following 48-hr exposure to the water-soluble fraction (WSF) of Cook Inlet crude oil at 75% of the LC50. Exposure to 25 and 50% of the LC50 did not significantly reduce swimming performance. Plasma cortisol concentrations were highest in fish exposed to both the combined stress of WSF exposure and of forced swimming in a stamina tunnel.

Animals↗

Sexual experience and responses to a birth control film.

The objective of this research was to examine the relationship between sexual experience and sexual and contraceptive attitudinal responses to a birth control film. A questionnaire was administered immediately before and after showing a birth control film to 103 college females. Subjects were classified into three groups according to their sexual and contraceptive experience. With perceived change measures, it was found that the film reinforced sexual and contraceptive beliefs. Significant group differences were found regarding reinforcement of sexual attitudes but not for contraceptive attitudes.

Evaluation Studies as Topic↗

Evaluation of the overland runoff mode of land wastewater treatment for virus removal.

The removal of enteric and tracer viruses by the overland runoff mode of domestic wastewater treatment was evaluated. Raw and primary and secondary treated wastewaters were sprayed onto grass-covered, 36-m soil plots of fine, sandy loam overlying an impermeable clay subsoil. Tracer bacteriophage f2 was seeded into the applied wastewaters, which were subsequently sampled at several points along the length of the plots. Assay of effluent samples revealed modest tracer virus removals of 30 to 60%. Data from timed experiments indicated that advancement of tracer virus to the bottom of the slopes proceeded at the same rate as wastewater, reaching the plot effluents within 50 to 90 min after application. Indigenous enteric virus levels were reduced by approximately 68 to 85% during migration down the treatment slopes. Soil sampling revealed that, although some f2 virus was found associated with the wastewater-saturated topsoil, little penetration of virus into the soil profile occurred. Laboratory soil adsorption studies revealed that poliovirus I was adsorbed much more readily than f2 virus. Comparison of virus removal characteristics during overland runoff with chemical removal characteristics of wastewater did not reveal any obvious correlations that could be used to predict virus removal.

Adsorption↗