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Biomedical subjects

A G Ershow

Publications and source records attributed to A G Ershow.

26 records · Page 2Linked to original sources
PubMed1985

A case-control study of trophoblastic diseases in the People's Republic of China.

A case-control study is currently under way in Beijing, People's Republic of China, involving approximately 165 patients with invasive moles or choriocarcinoma, 165 with hydatidiform moles, and 330 population controls, who were matched to the patients with invasive moles or choriocarcinoma on age and interval since last pregnancy. The interviews are focused on a number of suspected risk factors, including previous pregnancy outcomes, history of hydatidiform mole, medical factors, drug usage, family history, and diet. A brief background of the study and methods as established through a previous pilot study are given.

China↗
PubMed1985

Nutritional status of the high esophageal cancer risk population in Linxian, People's Republic of China: effects of vitamin supplementation.

Plasma levels of nutrients in 196 individuals were assayed as part of a study of the feasibility of a nutrition intervention trial in Linxian, a county in North Central China with exceptionally high rates of esophageal cancer. High-performance liquid chromatography analyses of samples collected in April 1983 showed low (relative to United States standards) base-line levels for retinol, alpha-tocopherol, and beta- and alpha-carotene. Repeat sampling in August 1983 revealed significantly increased plasma levels of retinol and alpha-tocopherol among those who had in the interim received daily supplementation with multivitamin pills containing the Recommended Dietary Allowance levels of those nutrients but not among those without supplementation. Levels of carotenes, which were not included in the pills, tended to increase regardless of supplementation, consistent with seasonal variations in availability of carotenoid-containing foods. Atomic absorption spectrophotometry analyses showed essentially normal levels of copper and zinc in plasma. Neither was affected by vitamin supplementation (the pills did not contain minerals) nor seasonal variation. The data are generally consistent with prior biochemical surveys in indicating marginal or low status of several nutrients in Linxian and in showing that supplementation with vitamins can effectively raise blood nutrient levels.

Adult↗
PubMed1985

A case-control study of esophageal cancer in Linxian, People's Republic of China.

A case-control study involving interviews with 1,200 patients with esophageal cancer and 1,200 population-based controls has been initiated in Linxian, a county in North Central China with perhaps the world's highest mortality rates for this tumor. Here we describe the rationale, study methods, and results of a pilot study that established the feasibility of the investigation.

China↗
PubMed1985

A pilot vitamin intervention trial in Linxian, People's Republic of China.

A 24-week pilot study of daily or weekly multiple vitamin supplementation among 852 adults in Linxian, where the rate of esophageal cancer is exceptionally high, demonstrated the feasibility of an intervention trial in this population. Compliance, when judged by pill count, was high for both frequencies of pill use. Only 2% of the subjects refused to take any pills, and, among pill takers, over 95% were reported to be taking most of their pills at the end of the study. Biochemical confirmation of high compliance was demonstrated in urine and blood tests, which showed markedly improved vitamin levels after supplementation. Results of the pilot study indicated that a system in which barefoot doctors were used in pill distribution was effective and that established field operating procedures for a full-scale intervention trial in this area were acceptable.

Adult↗
PubMed1984

Vitamin A and other deficiencies in Linxian, a high esophageal cancer incidence area in northern China.

Biochemical analyses were conducted to evaluate the nutritional status of a high esophageal cancer risk population in Linxian, People's Republic of China. A study was conducted in September 1980 in which plasma levels of vitamins A, B2, and C were analyzed. In a second study in 1983, the plasma fat-soluble vitamins were analyzed with a newly developed high-performance liquid chromatography method that allowed the simultaneous determination of retinol, alpha-tocopherol, beta-carotene, alpha-carotene, and lycopene in 0.1 ml of plasma sample. The average plasma retinol levels ranged from 24 to 27 micrograms/dl among the population groups, with 20-35% of the individuals having levels under 20 micrograms/dl. Low plasma beta-carotene levels averaging 8-12 micrograms/dl were observed among the population groups. Low plasma alpha-tocopherol levels with average values around 700 micrograms/dl were also observed; about half the individuals were either low or deficient in vitamin E. After 4 months of supplementation with daily multivitamin tablets, the plasma contents of retinol and alpha-tocopherol were significantly increased. The plasma alpha-carotene and beta-carotene were also increased, possibly as a reflection of seasonal changes in the diet or a sparing effect of vitamins A and E on these carotenes. Low plasma ascorbate levels with an average of 567 micrograms/dl were observed, and about 23% of the individuals had values under 200 micrograms/dl. Riboflavin deficiency was prevalent, with about 90% of the subjects having an erythrocyte glutathione activation coefficient over 1.2. The study establishes the low nutritional status in vitamins of the population in Linxian and provides the background for further studies on the effects of nutritional deficiency on carcinogenesis.

Adult↗
PubMed1984

Compliance and nutritional status during feasibility study for an intervention trial in China.

As part of a pilot study to assess the feasibility of a long-term intervention trial to be done in Linxian, People's Republic of China, nutritional status and compliance were assessed in villagers taking daily multivitamin pills containing the U.S. Recommended Dietary Allowances (RDA). Before the start of the trial and again during its 4th month, nutritional status was assessed by laboratory tests and a dietary interview. Compliance was assessed in all subjects by pill counts and in a subset by urinary riboflavin loading-dose tests. At the outset of the trial, the study population had widespread biochemical and dietary deficiencies of ascorbic acid and riboflavin. As expected, subjects taking a daily pill had significantly improved status for these vitamins during the study. Compliance as measured by pill counts was excellent, with over 90% of the subjects taking at least 80% of their daily pills. Mean urinary excretion of a riboflavin loading dose entered and remained in the normal range after 3 weeks of supplementation, indicating that compliance did not fall off over time. Compliance was similar in normal subjects and in those with a prior diagnosis of esophageal dysplasia. Compliance also was nearly as good in subjects receiving monthly home visits as in those receiving weekly home visits from the barefoot doctor (village paramedical worker). The results of this pilot study indicated that a long-term intervention trial was feasible in Linxian and that the RDA dose level of vitamins was effective in ameliorating certain nutritional deficiencies prevalent in the study population.

Adult↗
PubMed1981

Separation of the dietary fat and cholesterol influences on plasma lipoproteins of rhesus monkeys.

In order to isolate the effects of the type of dietary fat from those of dietary cholesterol on the circulating pool of cholesterol, plasma lipoproteins were characterized in juvenile rhesus monkeys fed semipurified diets containing 31% of calories as corn oil or coconut oil. Half the diets contained 300 mg of cholesterol per 1000 kcal. The fatty acids of cholesteryl esters and phospholipids varied significantly with dietary fat such that saturated and monounsaturated fatty acids replaced polyunsaturated fatty acids in low-density lipoproteins (LDL) and high density-lipoproteins of rhesus monkeys fed coconut oil. Dietary cholesterol alone induced small but significant increases in the cholesteryl ester: triglyceride ratio in both very low-density lipoproteins and LDL. Whereas neither saturated fat (coconut oil) nor cholesterol alone substantially altered the plasma cholesterol concentration or lipoprotein profile, together these dietary components interacted synergistically to produce a significant elevation in plasma cholesterol. This was due primarily to a significant rise in the cholesteryl ester fraction of LDL, disproportionate to any change in LDL protein concentration. The data are consistent with current hypotheses that relate parameters of LDL turnover and clearance to their macromolecular structure and physicochemical characteristics.

Animals↗