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Biomedical subjects

C Stafford

Publications and source records attributed to C Stafford.

15 recordsLinked to original sources
PubMed1986

Affirmative action at work: a survey of graduates of the University of California, San Diego, Medical School.

Reported here are the results of a mail survey of 113 graduates from the University of California, San Diego, School of Medicine. Fifty-seven had been admitted with assistance of the Special Admissions Subcommittee (SAS) and 56 had been admitted through the traditional Recruitment and Admissions Committee mechanisms. SAS graduates see more patients daily, and practice more often in primary care specialties in rural and inner-city areas, providing medical care for ethnic minorities from lower socioeconomic strata.

California↗
PubMed1981

Cholesterol and bile acid balance in Macaca fascicularis. Effects of alfalfa saponins.

We determine the effects of alfalfa top saponins on cholesterol and bile acid balance in eight cynomolgus macaques (Macaca fascicularis). The monkeys ate semipurified food containing cholesterol with or without added saponins. The saponins decreased cholesterolemia without changing the levels of high density lipoprotein-cholesterol; hence, they reduced the total cholesterol/high density lipoprotein-cholesterol ratio. Furthermore, they decreased intestinal absorption of cholesterol, increased fecal excretion of endogenous and exogenous neutral steroids and bile acids, and decreased the percent distribution of fecal deoxycholic and lithocholic acids. The fecal excretion of fat was also slightly increased, but steatorrhea did not occur. We saw no signs of toxicity in the monkeys after 6 or 8 wk of saponin ingestion. The data suggest that alfalfa top saponins may be of use in the treatment of patients with hypercholesterolemia, but long-term studies on possible toxicity are needed before this therapy can be recommended for humans.

Animals↗
PubMed1980

Alfalfa seeds: effects on cholesterol metabolism.

Plasma cholesterol concentrations were reduced in 3 human volunteers during ingestion of diets containing alfalfa seeds (AS) for 3 weeks. No signs of toxicity were detected through serum determinations of multiple parameters. The ingestion of AS in rats decreased the concentration of plasma cholesterol, reduced intestinal absorption of exogenous and endogenous cholesterol, and increased fecal biliary excretion.

Adult↗
PubMed1980

Alfalfa saponins and alfalfa seeds. Dietary effects in cholesterol-fed rabbits.

Since alfalfa meal prevents hypercholesterolemia and atherosclerosis in rabbits and alfalfa saponins prevent the expected rise in cholesterolemia induced by dietary cholesterol in monkeys, the experiments being reported here were performed to determine whether alfalfa saponins affect atherogenesis in rabbits. In addition, the effects of alfalfa seeds were studied. Cholesterol-feb rabbits were randomly assigned to 3 groups: (a) control animals (N = 18); (b) animals maintained on a diet containing 1.0 to 1.2% alfalfa saponins (N = 18); and (c) animals maintained on a diet containing 40% alfalfa seeds (N = 17). Results after a 4-month observation period demonstrated that alfalfa saponins and alfalfa seeds reduce hypercholesterolemia, aortic sudanophilia, and the concentration of cholesterol in aortic intima-plus-media and in the liver, but do not induce changes in the hematocrit.

Animals↗
PubMed1980

Organochlorine and heavy metal residues in black duck eggs from the Atlantic Flyway, 1978.

Black duck (Anas rubripes) eggs were collected during 1978 in the Atlantic Flyway. One egg from each of 49 clutches was analyzed for organochlorine compounds and mercury. DDE was detected in 39 eggs, ranging from 0.09 ppm to 3.4 ppm, wet weight. DDE residues were highest in eggs from Delaware, where the mean DDE level was 2.0 ppm. DDT and TDE were present at low levels in only five and four eggs, respectively. PCBs resembling Aroclor 1260 were detected in 24 eggs and ranged from 0.43 ppm to 2.9 ppm. Eggs from Massachusetts and Rhode Island contained an average of greater than 1.0 ppm PCBs, but eggs from Nova Scotia, Pennsylvania, Maryland, and Virginia contained no detectable PCBs. Dieldrin, oxychlordane, and heptachlor epoxide were present in a few samples at low levels. Mercury was detected in 31 eggs, ranging from 0.07 ppm to 0.34 ppm, wet weight. Twenty eggs analyzed for chromium, copper, and arsenic contained averages of 0.64 ppm, 1.7 ppm, and 0.18 ppm, respectively. No geographic pattern was observed in these metal residue levels. Eggshell thickness (0.347 mm) was identical to the pre-1946 norm.

Animals↗
PubMed1979

Comparative effects of alfalfa saponins and alfalfa fiber on cholesterol absorption in rats.

Intestinal absorption of cholesterol was measured in control rats fed semipurified diets and in rats fed alfalfa meal, in which saponins had been previously extracted, or this extracted material plus alfalfa saponins. A dose of 2 mg radioactive cholesterol was administered intragastrically, and fecal excretion of labeled neutral steroids measured. Absorption of cholesterol was about 76% in control animals, and about 47% in alfalfa-red rats. Extraction of saponins from alfalfa eliminated the cholesterol absorption-lowering effect, while addition of 0.26% alfalfa saponins to the extracted alfalfa restored its activity. The results demonstrate that alfalfa saponins are responsible for the effect of alfalfa meal in reducing cholesterol absorption, and that alfalfa fiber is not involved in this activity.

Animals↗
PubMed1978

Prevention of hypercholesterolemia in monkeys (Macaca fascicularis) by digitonin.

Digitonin mixed in the diet was well tolerated by rats and cynomolgus monkeys (Macaca fascicularis), and prevented the expected rise in plasma cholesterol in monkeys fed a diet containing butter and cholesterol. Both digitonin and mildly hydrolyzed digitonin precipitated cholesterol dispersed in micellar suspensions and decreased intestinal absorption of cholesterol in rats, but only digitonin bound cholesterol in vitro. The hypocholesterolemic effect of digitonin may be secondary to decreased intestinal absorption of cholesterol associated with a disturbance in the micellar suspension of cholesterol in the intestinal content. Modification of other mechanisms that may be involved in membrane transport of cholesterol through the intestinal epithelium is not ruled out by the present findings.

Animals↗
PubMed1977

Effect of alfalfa saponins on intestinal cholesterol absorption in rats.

Five to 20 mg of saponins obtained from alfalfa tops or roots were introduced intragastrically in rats also receiving oral and intravenous ring-labeled cholesterol. The saponins were tested before and after partial acid hydrolysis. Absorption of cholesterol was determined by estimation of fecal sterols and by a dual isotope technique involving assay of plasma radioactivity. Alfalfa top saponins (nonhydrolyzed) reduced absorption of cholesterol. Acid hydrolysis of alfalfa top or root saponins enhanced their ability to inhibit cholesterol absorption.

Animals↗