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Biomedical subjects

C K Clifford

Publications and source records attributed to C K Clifford.

25 records · Page 2Linked to original sources
PubMed1983

Effect of dietary triglycerides on lymphocyte transformation in rats.

Weanling rats were fed casein-based diets containing purified and mixed triglycerides to evaluate the effect of these lipids on mitogen-induced lymphocyte transformation, lymphoid organ weights, and fatty acid profiles of the total lipid in plasma, spleen, and thymus. Test lipids were added at a level of 8 g per 100 g of diet. All diets contained 0.82 g of safflower oil per 100 g. The digestibility coefficients for tristearin, tripalmitin, and trimyristin were 20, 37, and 85%, respectively. Digestibility coefficients for all remaining triglycerides were 90% or greater. The differences in mitogen-induced lymphocyte transformation among rats fed the various dietary lipids were unrelated to saturation of the lipid and correlated negatively with total lipid absorbed. Except for tripalmitin and tristearin, dietary lipids significantly altered the fatty acid profiles of the total lipids in plasma, spleen and thymus. It was concluded that the fatty acid profiles of the total lipid in plasma, spleen and thymus can be altered without accompanying major changes in mitogen-induced blood lymphocyte transformation. It was further concluded that mitogen-induced lymphocyte transformation was unrelated to saturation of dietary lipid and appeared to be associated negatively and weakly with the quantity of dietary lipid absorbed.

Animals↗
PubMed1983

Purine synthesis and reutilization in folate-deficient rat hepatocytes.

Although folic acid is known to be involved in the pathways of purine metabolism, the precise changes brought about in purine synthesis, reutilization, pool sizes, and ratios by experimental folate deficiency are not clear. Consequently, these aspects of purine metabolism were measured in hepatocytes from control and folate-deficient rats fed an amino acid diet with and without folic acid, respectively. Purine synthesis and reutilization were measured as the rates of incorporation of [U-14C]glycine and [G-3H]hypoxanthine, respectively, into the adenine and guanine pools of freshly isolated hepatocytes after a 3-hour incubation in folate-free, as well as folate- and/or thymidine-supplemented culture media. Hepatocytes from folate-deficient rats had the same rates of purine synthesis as those from control rats. Purine reutilization, purine pool sizes, and the adenine:guanine ratios were lower in hepatocytes from deficient compared with control rats. Purine synthesis was increased when folic acid or thymidine was added to the culture medium. Although hepatocytes from folate-deficient rats had a lower rate of purine reutilization compared with those from control rats, the reutilization rates did not respond to the addition of folic acid or thymidine to the culture medium. The data suggest that purine synthesis was not impaired but purine reutilization was diminished in folate deficiency. Thymidine was as effective as folic acid in stimulating purine synthesis in both control and folate-deficient hepatocytes.

Animals↗
PubMed1980

Effects of dietary proteins from a variety of sources on plasma lipids and lipoproteins of rats.

Five experiments were conducted to study the effect of various protein sources on fasting blood lipids and lipoproteins in the rat. Plasma levels of total cholesterol, high density lipoprotein (HDL)-cholesterol and total triglyceride, as well as weight gain, food intake protein efficiency ratio and net protein utilization were measured over 28-day test periods with male Sprague-Dawley rats. The purified proteins studied included casein, egg albumin, lactalbumin, soy and alfalfa. Crude proteins studied included yeast, fish meal and blood meal. Diets low in methionine were supplemented with this amino acid to insure that all diets were nutritionally adequate. Although the plasma total cholesterol levels varied by 40-50% and HDL-cholesterol by 90% among the various diets, the changes were not associated with any particular dietary protein source or level. Plasma total triglyceride levels varied independently of the dietary source and level of protein. Plasma HDL-cholesterol accounted for approximately 70% of the plasma total cholesterol. Plasma HDL-cholesterol concentrations correlated positively (R = 0.72) with plasma total cholesterol and negatively (R = -0.34) with plasma triglyceride levels. These results clearly show that the pure and crude plant proteins did not have a hypocholesterolemic effect compared with pure and crude animal proteins in rats. Plasma HDL-cholesterol levels were the same in rats fed plant and animal proteins.

Animals↗
PubMed1980

Plasma high density lipoproteins and coronary artery disease.

Plasma lipid samples and other atherosclerosis risk factors were related to presence of extent of coronary artery disease (CAD) in 102 consecutive patients undergoing coronary angiography. Thirty-six were without CAD and 66 had angiographically documented CAD. In CAD, high density lipoprotein (HDL) cholesterol was lower and total cholesterol and low density lipoprotein cholesterol were higher than in subjects without CAD. Further, HDL was inversely related to extent of CAD (number of major obstructed vessels). Moreover, decreased HDL was the single most important determinant of CAD among all atherosclerosis risk factors (more so in females than in males). In addition, reduced plasma enzymatic activity of lecithin:cholesterol acyltransferase (LCAT) correlated with the presence and extent of angiographically shown CAD. These findings document the protective effect of elevated plasma HDL against coronary obstructive disease and suggest this salutary action may be related to LCAT mobilization of cholesterol from atherosclerotic lesions.

Arteriosclerosis↗
PubMed1978

Composition of and cholesterol in Araucana and commercial eggs.

Araucana eggs from six sources and commercial-type white eggs of two major supermarket brands and from the University of California flock were collected and analyzed for cholesterol content of the yolk. The yolks of Araucana eggs were significantly higher in cholesterol than those of commercial white eggs.

Cholesterol↗