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Biomedical subjects

D Kritchevsky

Publications and source records attributed to D Kritchevsky.

At least 361 records · Page 20Linked to original sources
PubMedDate not supplied

Quantitative recovery of lipids from aortas stained with sudan IV.

The separation of Sudan IV from lipid extracts of stained aortas can be accomplished by thin layer or column chromatography, but the most convenient method involves adsorption of the dye to activated carbon. The aortic lipids are thus recovered quantitatively.

Animals↗
PubMedDate not supplied

Cholesterol vehicle in experimental atherosclerosis. Part 18. Comparison of North American, African and South American peanut oils.

Peanut oils were obtained from the United States (NAPNO), Africa (APNO), and South America (SAPNO) and their effects on atherosclerosis in rabbits fed 2% cholesterol were determined. The major differences among the oils were in the content of oleic (NAPNO, 48.9%; APNO, 58.6%; SAPNO, 36.4%) and linoleic (NAPNO, 29.6%; APNO, 21.7%; SAPNO, 41.1%) acids. In a series of 4 experiments it was found that South American peanut oil was 7% more atherogenic than African peanut oil and 18% more atherogenic than North American peanut oil. American peanut oil was 14% more atherogenic that corn oil (CO). South American peanut oil gave highest serum and liver lipid levels. The differences in atherogenicity may be due to the structure of the triglycerides of the various peanut oils.

Africa↗
PubMedDate not supplied

Cholesterol exchange between the red blood cells and plasma of young and old rats.

The exchange of unesterified cholesterol between plasma and red blood cells of young (1.5 month) and old (1-2 years) rats was studied using [3H]-cholesterol as label. Using labeled plasma and unlabeled red blood cells, no equilibration of specific activity of unesterified cholesterol with the specific activity of cholesterol of red blood cells occurred in either young or old rats. Using labeled red blood cells and unlabeled plasma, equilibration of radioactivity of cholesterol was observed in both young and old rats. However, a more rapid exchange of free cholesterol was observed when labeled old red blood cells were incubated with unlabeled plasma. This apparent paradox may be explained by the existence of a larger, more readily exchangeable pool of free cholesterol in red blood cells of old rats than of young rats. Red blood cells and plasma of old rats contained significantly more free cholesterol than those of young rats but phospholipid levels were comparable.

Aging↗
PubMedDate not supplied

Caloric restriction and experimental mammary carcinogenesis.

It has been demonstrated repeatedly that caloric restriction, or underfeeding, will inhibit the growth of spontaneous, transplanted, or induced tumors in mice and rats. Caloric restriction will inhibit tumorigenesis even in the face of a high fat diet. The mechanism of action is moot but caloric restriction reduces plasma insulin levels, increases activities of antioxidant enzymes, and enhances DNA repair. It also reduces oncogene expression. The cancer growth-inhibiting action of caloric restriction may be reversed by adrenalectomy.

Animals↗
PubMedDate not supplied

Independent effects of diet and nutritional status on apoprotein B gene expression in rabbit.

The separate effects of dietary composition and time of nutrient intake on apoprotein B (apo B) gene expression in rabbit intestine and liver were determined. After an overnight fast, there were insignificant effects of the long-term consumption of a diet containing saturated fat on the tissue levels of apo B mRNA, although plasma cholesterol levels were elevated as compared to those of animals consuming a diet containing unsaturated fat. However, when the animals were studied 2 hours after receiving a gastric tube feeding of a portion of their test diets after an overnight fast, there was a twofold increase in the intestinal apo B mRNA level and a similar increase in the transcriptional activity of the apo B gene independent of dietary composition. We conclude that, with the diets we used, nutrient intake alone has, in rabbits, a major effect on apo B gene expression at the level of transcription. This factor should be taken into account when designing studies of intestinal gene expression.

Actins↗