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Biomedical subjects

A Goodwin

Publications and source records attributed to A Goodwin.

44 records · Page 3Linked to original sources

Echocardiographic visualisation of the interatrial baffle after Mustard's operation.

Thirty children aged from 7 weeks to 14 years were examined by echocardiography after Mustard's operation for transposition of the great arteries. Discrete and persitent echoes were noted within the original left atrial cavity and contrast echocardiography was used to establish that these originated from the interatrial baffle. In the presence of caval channel obstruction, caused by malposition or shrinkage of the baffle, significant differences were seen in the echocardiographic appearances of the baffle, namely limitation of baffle motion, thickening, and multiplicity of the baffle echoes. These findings suggest that the technique may be of value in the postoperative assessment of patients with transposition of the great arteries.

Adolescent↗

Stress modification of the toxicity of antimotion sickness drugs and aspirin.

The effect of environmental temperature on the toxicity of cyclizine, trimethobenzamide, and Aspirin were studied in mice. LD50s were compared at 30 degrees C (warm), 22 degrees C (normal), and 15 degrees C (cool). At 30 degrees C the toxicity of all three drugs increased, with that to aspirin being affected most. Cooling decreased the toxicity of cyclizine and had no significant effect on that of trimethobenzamide or Aspirin. These findings indicate that alterations in environmental temperature markedly affect drug toxicity. They emphasize that such alterations, and particularly increases in temperature, do not have to be particularly drastic, but that "mild' variations in the environment are effective in altering an animal's sensitivity to a drug.

Animals↗

Response of mice to repeated photoperiod shifts: susceptibility to stress and barbiturates.

Three inbred strains of mice selected for their spontaneous aggressive behavior and differential susceptibility to stress were exposed to a controlled environment where on an average of once every 4 days for 76 days and subsequently on an average of once every 2 days for an additional 55 days a 12L:12D photoperiod was reversed by 180 degrees. This procedure did not affect the growth of the mice and appeared to reduce fighting. However, plasma corticosterone concentrations in all three strains of mice were high, and their response to a 24-hr cold stress was no longer evident. The most pronounced effect of the altered photoperiod was on the barbiturate-induced sleeping time which showed a 40% reduction in all strains in spite of differential suceptibility to the drug among strains. It is concluded that repeated random phase shifting by varying the photoperiod is a stressful experience to which animals do not adapt and that the ability to respond to an additional stimulus or drugs may be greatly altered.

Aggression↗