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Biomedical subjects

D Kritchevsky

Publications and source records attributed to D Kritchevsky.

At least 199 records · Page 11Linked to original sources
PubMed1980

Influence of type of carbohydrate on atherosclerosis in baboons fed semipurified diets plus 0.1% cholesterol.

Five groups of six (three male, three female) baboons (Papio ursinus) were maintained for 17 months on a semipurified diet containing 40% carbohydrate, 25% casein, 13.9% coconut oil, 0.1% cholesterol, 15% cellulose, 5% salt mix (USP XIV) and 1% vitamin mix. The carbohydrates fed were: fructose, sucrose, starch, glucose, and lactose. A fifth group was used as control and was fed bread, fruit, and vegetables. Serum, liver, and tissue lipids were analyzed at the end of the feeding period as were cholesterol absorption (as 3H-cholesterol) and synthesis (from 14C-mevalonic acid). Serum cholesterol and beta-lipoprotein levels were elevated in all the test groups compared to final control levels or to starting levels for all the baboons. Average serum cholesterol levels of the test groups were not significantly different. Liver lipids were elevated in all test groups except that fed glucose. Baboons on the test diets absorbed more exogenous cholesterol (3H) but biosynthesis of this sterol was not inhibited. The ratio of biliary primary/secondary bile acids was below normal levels only in the animals fed fructose and sucrose. Cholesteryl ester fatty acid spectra of serum and liver reflected the dietary fat. Fecal weight was 69% higher in lactose fed animals and 31% lower in sucrose fed animals than in the controls. The ratio of endogenous or exogenous neutral/acid steroids was considerably lower in the fructose-fed baboons than in the other animals. On this diet average aortic sudanophilia (percentage of surface) was: fructose, 11.3; sucrose, 10.4; starch, 21.3; glucose, 17.2 lactose, 65.8; and control, 1.4. Gross atheromatous lesions were seen in five of six baboons fed lactose; three of six baboons fed fructose; two of six baboons fed sucrose, and one of six baboons fed starch. In a second experiment three groups of baboons were fed the control diet, the semipurified diet in which the carbohydrate was lactose, and the semipurified diet containing lactose plus 0.1% cholesterol for 8.5 months. Serum lipids were elevated in the two test groups but liver lipids were not significantly different from control levels. Average aortic sudanophilia (percentage of area) was: lactose, 2.2; lactose-cholesterol, 20.8; and control, 0.3%. One of the six baboons in the lactose-cholesterol group had visible atherosclerotic lesions. These experiments represent the first successful attempt to produce severe atherosclerosis in baboons by dietary means alone.

Animals↗
PubMed1979

Physical properties of human serum hexosaminidases A and B: studies in normal and cancer patients.

The major forms of human serum hexosaminidases A and B (Hex A and Hex B) were isolated from normal subjects and cancer patients using DEAE-cellulose. In normal serum, Hex A was heat-labile and had an apparent KM of 1.13 mM and Vmax of 0.51 mumol/ml/h; Hex B was heat-stable and had an apparent KM of 0.85 mM and Vmax of 0.22 mumol/ml/h. Both forms had the same pH optimum, at 4.3. Hex A and Hex B from the sera of cancer patients resembled their normal counterparts in heat stability, pH optimum, and apparent KM (1.07 mM for Hex A, 0.88 mM for Hex B). In contrast, the Vmax values for the cancer sera isozymes were greater than those of normal sera (0.70 and 0.40 mumol/ml/h for Hex A and Hex B, respectively).

Hexosaminidases↗
PubMed1979

Influence of vegetable protein on gallstone formation in hamsters.

The lithogenic diet generally used for production of gallstones in hamsters contains 20% casein. In four separate experiments the 20% casein diet was compared with one containing 20% soy protein. All other components were kept constant. Two of the four experiments were of 45-day duration, one of 70 days and one of 100 days. When results of all four experiments were averaged, 57.5 +/- 3.6% of hamsters fed casein exhibited cholesterol gallstones whereas only 14.0 +/- 1.3% of soy protein-fed hamsters had gallstones. Thus, soy protein has a significant inhibitory effect on gallstone formation in hamsters. When soy protein was fed to hamsters with preestablished gallstones there was evidence of gallstone dissolution.

Animals↗
PubMed1979

Influence of whole or skim milk on cholesterol metabolism in rats.

Male Wistar rats were fed commercial ration and given whole milk, skim milk, or water to drink. After 3 weeks the control group showed the greatest weight gain. Rats given whole milk had the smallest livers. Serum cholesterol levels were significantly lower in rats fed either whole or skim milk, but other serum lipids were unaffected. Liver triglyceride levels were lowest in the rats on skim milk. Activities of hepatic fatty acid synthetase, hydroxymethyl-glutaryl coenzyme A reductase and cholesterol 7alpha-hydroxylase were similar in the two milk-fed groups and considerably lower than in the controls.

Animals↗
PubMed1979

Clinical experience with the soybean protein diet in the treatment of hypercholesterolemia.

The efficacy of the total substitution of animal proteins with a textured soybean protein in hypercholesterolemic individuals was assayed in 42 in-patients and 18 out-patients. The in-patients studied followed one of three different crossover protocols: in protocol A, the soybean diet was compared with a standard low lipid diet; protocol B compared two soybean diets, one with added cholesterol, one without; and protocol C compared a soybean diet containing a high P/S fatty acid ratio to one with a low P/S ratio. In all three protocols, the soybean regimen provided valid and reproducible hypocholesterolemic effects that were not modified by the addition of cholesterol. P/S variations appeared, however, to modify the final effect: soybean definitely had a decreased effectiveness with a low P/S (0.1) regimen. The overall plasma cholesterol changes in the 42 in-patients after 3 weeks on the different soybean diet protocols was -20%. Patients with type IIA and IIB hypercholesterolemia provided almost equivalent results, whereas patients with mixed phenotypes (IIB-III) appeared somewhat more sensitive to the dietary effect. Cholesterol decreased mostly in the low density lipoprotein fraction, but some very low density lipoprotein changes were also noted upon variation of the P/S ratio. The out-patients studied provided less satisfactory results. possibly due to the difficulty of adequately complying with the diet. These studies indicate that treatment with the soybean diet is an effective regimen for inducing a significant cholesterol reduction in type II patients refractory to standard low lipid regimens.

Adult↗