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Biomedical subjects

J M Donald

Publications and source records attributed to J M Donald.

27 records · Page 2Linked to original sources
PubMed1986

Stereoselective behavioral effects of the isomers of pentobarbital and secobarbital in the pigeon.

Little information is available on the contribution of the isomers of pentobarbital and secobarbital to the behavioral effects of the racemic mixtures. To determine the contribution of each isomer on food-maintained behavior, pigeons were trained to respond under either a multiple fixed-ratio 30, fixed-interval 600 (mult FR30 FI600) schedule, or a multiple fixed-ratio 30, variable-interval 60-sec (mult FR30 VI60) schedule under which every response under both the FR and VI components also produced a brief electrical shock (punishment). Dose-response curves were determined separately for each isomer of pentobarbital (1-17.5 mg/kg i.m.) and secobarbital (1-17.5 mg/kg i.m.). Under the mult FR30 FI600 schedule, the S-(-)-isomers of pentobarbital and secobarbital were slightly less than 2-fold more potent than the R-(+)-isomers, but both isomers produced qualitatively similar effects on responding. The S-(-)-isomers of both barbiturates produced increases in punished responding under the mult FR30 VI60 at lower doses than the R-(+)-isomers. At high doses (greater than 10 mg/kg), the S-(-)-isomers suppressed responding early in the session resulting in a lower average rate of punished responding for the session than the R-(+)-isomers. The peak increase in punished responding was observed after 10 mg/kg of the R-(+)-isomers of pentobarbital and secobarbital. These results indicate that the effect of the isomers of pentobarbital and secobarbital on mult FR30 FI600 responding and on suppressed responding are qualitatively similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1981

Pseudopseudohypoparathyroidism with lymphoedema and abnormal dermatoglyphics.

This paper describes a woman with pseudopseudohypoparathyroidism (PPHP) who had intractable lymphoedema and also abnormal dermatoglyphics. The findings were quite distinct from those in two previously reported cases of pseudohypoparathyroidism (PHP). Dermatoglyphics may prove useful in the diagnosis of PPHP but may also provide a clue to the factors which distinguish PPHP from PHP.

Adult↗
PubMedDate not supplied

Neurobehavioral effects in offspring of mice given excess aluminum in diet during gestation and lactation.

Aluminum (Al) as Al lactate in a purified diet (25, 500 or 1000 micrograms Al/g diet) was fed to Swiss-Webster mice from conception through weaning. Weights, food intake and toxic signs were recorded at regular intervals and pregnancy outcome evaluated. Pups were assessed for growth, neurobehavioral development and toxic signs prior to weaning. Offspring were also evaluated with a multi-item neurobehavioral test battery immediately after weaning and again after a 2-week period during which they were all fed control (25 micrograms/g Al) diet. No maternal or reproductive toxicity was detected and there were no group differences in pup mortality, growth, toxic signs, or neurobehavioral development prior to weaning, with the exception of poor performance in a climbing test in the 1000 micrograms Al/g diet group. Parameters significantly affected by Al in the postweaning neurobehavioral testing were foot splay, forelimb and hindlimb grip strengths, and thermal sensitivity. Negative geotaxis was inconsistently affected and startle responses were not affected. These results show that maternal dietary exposure to excess Al during gestation and lactation which do not produce maternal toxicity can result in persistent neurobehavioral deficits in weanling mice.

Aluminum↗
PubMedDate not supplied

Effects of aluminum ingestion on spontaneous motor activity of mice.

Aluminum (Al) as aluminum lactate in a purified diet was fed to adult female Swiss-Webster mice over a six week period. Comparison groups were: controls (CON), 25 micrograms Al/g diet; low Al (LO), 500 micrograms Al/g diet; high Al (HI), 1000 micrograms Al/g diet; and pair fed (PF) 25 micrograms Al/g diet pair fed to HI group. Weights, food intake and toxic signs were recorded at 3-day intervals and activity levels were measured during a 24-hr session during week 5 using an automated apparatus. Food intake was not reduced overall in Al-treated groups but they demonstrated a cyclic pattern of food intake. Mean weight gain over the 6-week period in the HI (0.5 g) and PF(0.1 g) groups was somewhat less than that in the CON (2.3 g) and LO (2.0 g) groups. No neurotoxic signs were recorded in any group, but a dose dependent increase in localized fur loss was seen. Overall activity level was 20% lower in HI than CON groups, with vertical movement more affected than horizontal movement. HI mice were less active during the diurnal period of peak activity than CON mice and their activity periods were also somewhat shorter (130 vs. 200 min). Activity of LO and PF mice did not differ significantly from controls, although PF activity levels were more variable. These data demonstrate that short term feeding of aluminum at levels within an order of magnitude of estimated human intake can influence neurobehavioral function as indexed by motor activity.

Administration, Oral↗