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Biomedical subjects

D S Sheriff

Publications and source records attributed to D S Sheriff.

At least 19 recordsLinked to original sources
PubMed1994

Libyan family with hypercholesterolemia and increased high-density lipoprotein cholesterol in plasma.

Genetic deficiencies of cholesteryl ester transport protein (CETP) and hepatic lipase activities have been associated with hyperalpha-lipoproteinemias. Here we present a family of 11 members, of which 9, including the father, mother, 5 sons, and 2 daughters, show a marked increase in high-density lipoprotein (HDL) cholesterol alone with low plasma concentrations of triglycerides. Analyses of lecithin:cholesterol acyltransferase (LCAT) activity, cholesteryl ester transfer between HDL fractions, hepatic lipase (HL) activity, and lipoprotein lipase (LPL) activity in these cases showed that a decrease in the heparin-releasable HL activity was the possible cause of the marked increase of HDL2 fractions observed in nine of them. Such a defect in HL activity could significantly affect HDL metabolism in particular and lipoprotein metabolism in general. Evidently, a marked increase in serum total cholesterol due to abnormal metabolism of HDL cholesterol, separate from known causes of altered low-density lipoprotein cholesterol metabolism, e.g., a clearance or a receptor defect, is not uncommon. The coordinated action of HL, LCAT, LPL, and CETP may be essential for normal metabolism of plasma lipoproteins.

Adolescent↗
PubMed1992

Effect of gossypol on tissue levels of glutathione and thiobarbituric acid reactive products in rats.

Gossypol was administered in pubertal and adult rats and lipid peroxide formation and GSH levels were estimated in different tissues like liver, testis, heart and kidney. Gossypol caused low generation of lipid peroxides, measured as thiobarbituric acid reactive products (TBAR), without causing significant changes in tissue glutathione (GSH) levels. This effect was more pronounced in liver and testis as compared to other tissues. In vitro effect of gossypol to inhibit lipid peroxidation as observed in vivo suggested that binding of gossypol to plasma membranes may result in inhibition of lipid peroxide generation.

Age Factors↗
PubMed1992

Evaluation of semen quality in a local Libyan population.

Semen analyses was carried out in a population of 1250 randomly selected Libyan males. Two semen samples collected from each volunteer were subjected to the routine analyses following the World Health Organization recommendations. The Libyan population had a higher percentage of men with sperm density in the range of 40-60 millions/ml. The percentage of men with sperm counts above 100 millions/ml is comparatively lower than that is reported by MacLeod and Gold (9). The seminal plasma transferrin levels showed a positive correlation with sperm density and alpha-glucosidase activity with sperm motility.

Adolescent↗
PubMed1989

The effect of gossypol on serum lipoproteins of adult rats.

It has been shown that gossypol treatment brings about marked changes in plasma lipoproteins of certain species causing a marked fall in total cholesterol and LDL-cholesterol levels. Using Helena electrophoretic system the lipoprotein pattern in serum of adult rats treated with gossypol was studied. Gossypol treatment for 1 day and 7 days continuously did bring about changes in serum lipoprotein profile. A marked increase in VLDL-cholesterol and fall in LDL-cholesterol was observed in rats treated with gossypol which was more pronounced in the 7 days treated group. It did not bring about any marked change in total cholesterol level. It did cause an increase in serum triglyceride level. Heparin injection which brought about a fall in VLDL-cholesterol with a concomitant increase in HDL-cholesterol in control rats did not elicit changes in gossypol-treated rats. Thus, gossypol treatment appears to alter serum lipoprotein metabolism in rats also.

Alanine Transaminase↗
PubMed1988

Gossypol and testicular lipids of adult rats.

Testicular lipids act as source of energy, structural components of spermatozoa and precursors of androgen biosynthesis. Treatment with antispermatogeneic agents cause accumulation of testicular lipids. Gossypol, an effective antispermatogenic agent causes marked accumulation of testicular neutral lipids. It did not affect testicular phospholipids. Gossypol treatment did not bring about marked changes in the key enzymes like HMG Co A reductase, glucose-6-phosphate dehydrogenase malic enzyme and cytosolic isocitrate dehydrogenase involved in sterol biosynthesis. Thus, gossypol brings about marked accumulation of glycerides and esterified cholesterol in the testis due to its effect on spermatogenic elements of adult rats.

Animals↗
PubMed1988

Tea consumption and serum lipids in a Libyan population in Benghazi.

Libyan subjects are known to consume large amounts of tea. There are reports that consumption of tea is associated with a reduction in serum total cholesterol and LDL-cholesterol. In the present study an attempt has been made to study the effects of tea consumption on 604 local Libyan subjects at Benghazi. The study groups were divided into younger (20-40 years) and older age (41-65 years) groups. It was observed that there was a negative association between tea consumption and serum total cholesterol and LDL-cholesterol concentrations. It appears that tea consumption may be an independent factor influencing serum lipid levels.

Adult↗