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Biomedical subjects

K K Carroll

Publications and source records attributed to K K Carroll.

At least 127 records · Page 7Linked to original sources
PubMed1976

Effects of diet on catabolism and excretion of (26-14C)cholesterol in rats.

The catabolism and excretion of [26-14C]cholesterol was studied in rats on semisynthetic and commercial diets low in fat or containing 15% butter or corn oil. Rats on the low fat commercial diet oxidized the labeled cholesterol to 14CO2 at more than twice the rate of those on the semisynthetic diet. Fecal excretion of labeled lipid was also somewhat higher with the commercial diet. The added fats had little effect on rate of oxidation of cholesterol but dietary corn oil stimulated fecal excretion of labeled lipid. The rate of loss of labeled cholesterol through oxidation and excretion showed a positive correlation with cholesterol biosynthesis, as measured previously by acetate incorporation into cholesterol in rats on the same kinds of diet. A simple method for efficient trapping and counting of 14CO2 was developed, which facilitated measurement of low levels of 14CO2 in expired air. Estimation of bile acid production from the rate of oxidation of [26-14C]cholesterol to expired 14CO2 and the specific activity of plasma cholesterol gave somewhat higher values than those obtained by other methods. Possible reasons for this difference are discussed.

Animals↗
PubMed1976

Immunosuppressive activity of an extract of Listeria monocytogenes.

The effects of treatment of mice with an aqueous extract of Listeria monocytogenes on lymphoid populations and on immune responsiveness were studied. Thymus weight was decreased to a third of the control, whereas spleen weight was proportionally increased as the number of treatments was increased. The total numbers of cells in the thymus and bone marrow were diminished, whereas the number in the spleen was increased. Serum hemolysin production and plaque-forming cell response to sheep erythrocytes were suppressed in treated mice when the extract was given before administration of antigen. Spleen cells from treated mice failed to mount an antibody response upon transfer to syngeneic gamma-irradiated recipients, suggesting that potential antibody-producing cells were impaired by the treatment.

Adrenalectomy↗
PubMed1975

Feeding studies in rats with high protein fungus grown on natural gas.

Preliminary feeding studies were conducted with a high protein fungus (Graphium sp.) grown on natural gas. The biomass, containing approximately 50% protein, is considered a potential source of single cell protein. In short-term (1-week) experiments, rats gained weight when fed semisynthetic diets containing up to 40% of the biomass, although growth was depressed at the higher levels. Rats lost weight but survived for this length of time when fed biomass alone. Chronic toxicity was tested in a 5-month study with diets in which the casein (20% by weight) of the semisynthetic diet was either partially or entirely replaced by the proteinaceous biomass. Rats fed these diets grew more slowly but appeared normal and healthy, and no pathological changes were observed at autopsy. Some of these rats were fed a standard laboratory diet for an additional 10-month observation period, and at autopsy, one cortical adenoma of the kidney was found in a rat originally fed the lower level of Graphium biomass.

Amino Acids↗
PubMed1975

Experimental evidence of dietary factors and hormone-dependent cancers.

Current awareness of the importance of environmental factors such as diet in the etiology of human cancer has stimulated renewed interest in animal models for studying effects of diet on tumorigenesis. Diet can influence cancer in animals by affecting the initiation or subsequent preneoplastic stage of tumorigenesis, but it has less effect on tumor growth. Caloric restriction has a general inhibitory influence on tumorigenesis. Dietary fat, on the other hand, tends to promote tumorigenesis, but only certain types of tumors, such as mammary tumors, are affected. Both caloric restriction and dietary fat appear to act primarily during the preneoplastic state, and their effects on hormone-dependent tumors may be mediated through changes in the hormonal environment. Variations in other dietary factors, such as protein, vitamins, or minerals, above the levels required for normal maintenance seem to have little influence on the genesis or growth of tumors.

Animal Feed↗