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Biomedical subjects

G A Harrison

Publications and source records attributed to G A Harrison.

At least 127 records · Page 7Linked to original sources
PubMed1975

Ultrastructural alterations observed in mouse lung after prolonged He/O2 exposure.

Three generations of mice were exposed to an atmosphere of 80% helium and 20% oxygen. The parent generation, born and raised in air until the experiment began, was sacrificed in two groups--one after 160 d and the other after 350 d of exposure. The F1 generation, conceived in air, born and raised in an He/O2 environment, was sacrificed after 160 d. The F2 generation, conceived, born, and raised in the He/O2 atmosphere, was sacrificed also in two groups--one after 85 d and the other after 280 d. Lung tissue from these animals was prepared by conventional methods for ultrastructural study. The most obvious alteration observed was the extensive blebbing, possibly indicative of cellular edema, seen in both the capillary endothlium and the alveolar epithelium. In addition, a highly convoluted basement membrane was observed in many areas. There was debris in some of the alveoli and an increase in platelets in the capillaries.

Animals↗
PubMed1975

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: V. preflight studies on tolerance of pocket mice to oxygen and heat. Part II. effects on lungs.

An electron microscope examination was carried out on the lungs of 11 pocket mice (Perognathus longimembris) that breathed oxygen at 10 psi or 12 psi partial pressure over a period of 7 d, at the end of which time they were decompressed to sea-level O2 pressure, either suddenly or in 30, 60, or 90 min. Vesiculation was noted in the endothelium of the alveolarcapillary wall in most of the animals and, occasionally, blebbing. Some mitochrondria were swollen in a few of the animals. Alveolar exudate was, in general, sparse. Compared with the lungs of other rodents, the lungs of pocket mice appeared relatively resistant to the toxic effects of oxygen. This conclusion needs, however, to be tempered by the fact that 5% N2 was used in the tests reported here. Nonetheless, the results suggest that the oxygen pressures anticipated on the flight of Apollo XVII should be well tolerated by the pocket mice.

Adaptation, Physiological↗
PubMed1975

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: appendix III. evaluation of viscera and other tissues.

Histopathological findings in the lungs, livers, bone marrows, small intestines, gonads, kidneys, and other tissues of the four pocket mice (Perognathus longimembris) that survived the Apollo XVII flight were evaluated in the light of their immediate environment and as targest of HZE cosmic ray particles. Results of this study failed to disclose changes that could be ascribed to the HZE particle radiation. Decreased numbers of erythropoietic cells in the bone marrow of the flight mice were probably related to the increased oxygen pressure. The small intestine showed no changes. Ovaries and tests appeared normal. Two of the three surviving male flight mice displayed early stages of spermatogenesis, just as ground-based controls did at the same season. Abnormalities were also not found in the thyroid, parathyroids, adrenals, or kidneys. The status of the juxtaglomerular apparatus could not be evaluated. The lungs exhibited nonspecific slight rections. A variety of incidental lesions were noted in the livers of both the flight mice and their controls. The heart muscle showed nothing that could be regarded as pathological. Sections of skeletal muscle examined were free from significant change.

Adrenal Cortex↗
PubMed1974

Social class and marital distance in Oxford City.

A study has been made of social class distributions and their effects on marital movement in the city of Oxford from 1837 to the present day. The data have been obtained from the marriage registers of nine ecclesiastical parishes which transect the city. There is marked social class heterogeneity according to district, but when the data are combined some striking relationships between occupation and the distributions of marital distance emerge. In general distance decreases and amounts of city endogamy increase almost linearly as one moves from Class I to Class V. There appears to be, however, no very great increase in marital distance in this century as compared with the situation in the last two-thirds of the nineteenth century. Some of the differences between the social classes are due to differences in marital age, but even after this has been taken into account there remains a very statistically significant relationship between class and marital movement.

Adolescent↗