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Biomedical subjects

D Kritchevsky

Publications and source records attributed to D Kritchevsky.

At least 19 recordsLinked to original sources
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 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↗
PubMed1979

Effect of dietary alfalfa, pectin, and wheat bran on azoxymethane-or methylnitrosourea-induced colon carcinogenesis in F344 rats.

The effect of dietary alfalfa, pectin, and wheat bran on colon carcinogenesis was studied in female inbred F344 rats. Weanling rats were fed semipurified diets containing 0 or 15% alfalfa, pectin, or wheat bran. At 7 weeks of age, all animals except controls were given azoxymethane (AOM) sc at a dose rate of 8 mg/kg body weight/week for 10 weeks or methylnitrosourea (MNU) intrarectally at a dose rate of 2 mg/rat twice a week for 3 weeks. The AOM-treated group was autopsied 40 weeks and the MNU-treated group 30 weeks after the first injection of the carcinogen. No tumors were observed in the colon or other organs of untreated rats fed the various diets. The animals fed the alfalfa diet and treated with MNU had a higher incidence of colon tumors than did those fed the control diet or the diets containing pectin or wheat bran. The incidence of MNU-induced colon tumors did not differ between the animals fed the control diet or the diets containing pectin or wheat bran. However, the incidence of AOM-induced colon tumors in rats fed diets containing pectin or wheat bran was lower than that in rats fed the control diet or the alfalfa diet. These results thus indicate that the effect of fiber in colon carcinogenesis depends on the type of fiber and, possibly, the fiber's mode of action.

Animals↗