摘要:

The effects of short-term and long-term ascorbic acid supplements on plasma alcohol clearance were studied in 13 clinically healthy male subjects. Two dose levels of alcohol, 0.5 and 0.8 g/kg body weight, were used. Blood samples were taken at zero time, 0.5 hours, then hourly up to 6 hours after alcohol consumption for the measurement of plasma alcohol and ascorbic acid levels, red-cell reduced glutathione level, and plasma alanine aminotransferase activity. At both dosages of alcohol, short-term as well as long-term pretreatment with ascorbic acid significantly enhanced the clearance of plasma alcohol. Although long-term ascorbic acid pretreatment resulted in better alcohol clearance, no significant difference in alcohol clearance was found between short-term and long-term ascorbic acid pretreatment. The two dose levels of alcohol had no significant effect on the red-cell reduced glutathione concentration or plasma alanine aminotransferase activity.

ISSN:0731-5724    

DOI:10.1080/07315724.1990.10720368

出版商:Routledge    

年代:1990

数据来源: Taylor

摘要:

Commercial infant formulas, human milk, and lipid emulsions were analyzed for evidence of naturally occurring lipid peroxidation and for susceptibility to an in vitro oxidative challenge using neonatal rat lung, liver, or intestine homogenates. Peroxidation was assessed by quantitation of TBA reactants, diene conjugates, lipid peroxides, and ethane and pentane hydrocarbons. The peroxidation of commercial formulas and human milk was influenced by the nutrient composition, as PUFA and iron enhanced while vitamin E inhibited one or more of the peroxidation pathways. Formulas and lipid emulsions differed in their response to a biological oxidant challenge. Neither neonatal rat lung nor liver tissue were effective in peroxidizing the formula or human milk in vitro, but both formula and human milk were peroxidized by exposure to neonatal rat intestinal tissue. The lipid emulsion was readily peroxidized by neonatal rat lung, liver, and intestinal tissue. The influence of nutrition on survival in hyperoxia was also studied by exposing newborn rat pups to either air or greater than 95% oxygen in the course of feeding Ringer's lactate, Similac 24 + iron, human milk, or Intralipid 10%. The survival of newborn rat pups exposed to air or greater than 95% oxygen was affected by the type of diet received.

ISSN:0731-5724    

DOI:10.1080/07315724.1990.10720369

出版商:Routledge    

年代:1990

数据来源: Taylor

摘要:

To assess the potential influence of diet and endogenous peptide anabolic hormone secretion on exercise-related differences in body composition, we compared levels of macronutrient intake, insulinlike growth factor I (IGF-I), and fat-free mass (FFM) and fat mass (FM) in matched groups of exercising women with and without secondary hypothalamic amenorrhea. Women were tightly matched according to somatotype and grouped into those with exercise amenorrhea (EXam, n = 6), exercise eumennorhea (EXeu, n = 5), and sedentary eumennorheic controls (SED, n = 5). Although no between-group difference was observed in FFM, the EXeu subjects had a significantly lower fat fraction and a significantly elevated FFM/FM ratio. Kilocaloric and protein intakes did not differ between groups, but dietary fat intake was lowest and carbohydrate intake highest in the EXam subjects. Dietary macronutrients were not correlated with the FFM/FM ratio. However, levels of insulinlike growth factor I were significantly correlated to the FFM/FM ratio and there was a clear trend for the hormone to be highest in the EXeu subjects. We conclude that differences in body composition between exercising women with and without exercise-induced hypothalamic-pituitary dysfunction were related to an alteration in IGF-I secretion, although differences in macronutrient intake might also be a factor. Further studies are warranted to elaborate upon the dietary and hormonal factors regulating the body composition response to exercise.

ISSN:0731-5724    

DOI:10.1080/07315724.1990.10720370

出版商:Routledge    

年代:1990

数据来源: Taylor

摘要:

The purpose of this study was to examine prevalence of selected cardiovascular disease risk factors in eight Iowa counties. From a random sample of 35-54-year-old males and females in eight counties, data were collected on smoking, blood pressure, exercise, body weight, and diet. Thirty-one percent of the females and 29% of the males were current smokers. Twenty-two percent had elevated blood pressure on a single measure and 55% of these were previously undetected. Twenty-eight percent engaged in regular exercise. The most popular forms of exercise were walking and bicycling. The prevalence of overweight in females and males was 36 and 46%, respectively. Percentage of males classified as overweight was higher than in national studies. Twenty-four-hour dietary recalls showed males receiving at least 100% of their RDAs for eight indicator nutrients and females receiving at least 100% of the RDAs for all but calcium and iron. The diet appeared to be higher in fat (39% energy from fat) and saturated fat (P/S = 0.46) than the national diet and to include less consumption of low-fat dairy products and fish.

ISSN:0731-5724    

DOI:10.1080/07315724.1990.10720371

出版商:Routledge    

年代:1990

数据来源: Taylor

摘要:

The objective of this study was to determine the effects of a year of Zn supplementation on Zn concentrations in circulating cells and on cellular immune functions in the elderly. Subjects, aged 60-89, were given a placebo, 15 mg Zn, or 100 mg Zn daily for 12 months. All subjects also received a multivitamin/mineral supplement that contained no additional Zn. Blood samples were drawn and immune functions assessed prior to and at 3, 6, 12, and 16 months after beginning Zn supplementation. Subject diets were also assessed at each visit. Dietary folate, pyridoxine, alpha-tocopherol, copper, zinc, and magnesium were consistently below recommended intakes. Although plasma Zn increased significantly in the 100 mg Zn treatment group, concentrations of Zn in erythrocytes, mononuclear cells, polymorphonuclear leukocytes, and platelets were not significantly increased by zinc supplementation. Natural killer cell activity was transiently enhanced by the 100 mg/day dose of Zn. There was a progressive improvement in delayed dermal hypersensitivity (DDH) and in lymphocyte proliferative responses to two mitogens; this may have been due to one or more components of the multivitamin/mineral supplement administered to all study subjects. The enhancement of DDH was significantly greater in the placebo group than in either zinc treatment group. Thus, zinc had a beneficial effect on one measure of cellular immune function while simultaneously having an adverse effect on another measure of cellular immunity.

ISSN:0731-5724    

DOI:10.1080/07315724.1990.10720372

出版商:Routledge    

年代:1990

数据来源: Taylor

摘要:

Plasma cholesterol and other blood lipids were determined in 64 college juniors and seniors during January and February 1989 (before exercise) and again during April and May 1989 (after exercise). A 14-week period of self-selected exercise was interposed between the before and after exercise cholesterol determinations. Cholesterol concentrations ranged from 127-273 mg/dl (before exercise) to 131-261 mg/dl (after exercise) in this group of students who were 22 +/−1 years of age. There were no statistically significant differences in cholesterol concentrations between the genders. Students could be further subdivided into groups with low (144 +/−3 mg/dl, n = 12), medium (176 +/−6 mg/dl, n = 35), and high (224 +/−6 mg/dl, n = 17) concentrations of cholesterol. Only students in the high cholesterol group experienced a significant reduction in total cholesterol and low-density-lipoprotein cholesterol after 14 weeks of exercise. High-density-lipoprotein cholesterol concentrations were significantly higher in women than in men in both the medium and high cholesterol subgroups before and after exercise. From these results it appears that a significant fraction of the young adult college population could be at increased risk of coronary heart disease because of inappropriately high concentrations of cholesterol. Moreover, self-selected exercise, if engaged in regularly, can reduce blood cholesterol significantly in students with high cholesterol concentrations.

ISSN:0731-5724    

DOI:10.1080/07315724.1990.10720373

出版商:Routledge    

年代:1990

数据来源: Taylor

摘要:

The response to dietary treatment of patients with chronic post-infectious diarrhea and lactose intolerance was prospectively studied in 29 infants less than 1 year of age. All had gastroenteritis with diarrhea which persisted for more than 3 weeks. In the hospital, diarrhea continued and lactose intolerance was documented while being fed half-strength cow's milk formula. They were given dietary treatment with one of three formulas used for treatment of diarrhea in infancy. Improvement of diarrhea was more frequently achieved with Pregestimil when given as the initial therapy than with the other two formulas. With Pregestimil nine of 10 patients improved whereas only four of nine infants fed Portagen and one of 10 patients initially treated with soy formula improved. Pregestimil was also effective in three of five patients who initially failed to improve with Portagen and in four of eight patients tried with soy formula with or without carbohydrate. Additionally, in the patients who improved, recovery was more rapidly achieved with Pregestimil than with the other two formulas. Formula failures were due to intolerance to glucose polymers in three patients, possibly to protein in seven infants, and an intolerance to all nutrients in five patients. The improvement of the diarrhea was slower in patients who had evidence of colitis in rectal biopsies regardless of the dietary treatment given, but was not correlated with other variables, i.e., etiology of diarrhea, jejunal histology, or duration of diarrhea prior to treatment. However, as a group, the patients who failed to respond to Pregestimil were younger (less than 3 months of age), had more formula changes and associated infections, and were given more antibiotics; they also had more prolonged diarrhea before treatment and more severe jejunal mucosal lesions and jejunal bacterial overgrowth. The data suggests that Pregestimil seems to be the most effective formula for the treatment of infants with chronic post-infectious diarrhea and lactose intolerance.

ISSN:0731-5724    

DOI:10.1080/07315724.1990.10720374

出版商:Routledge    

年代:1990

数据来源: Taylor

摘要:

To obtain more insight into the effect of dietary fiber on vitamin B6 status among elderly people, we studied dietary interrelationships as well as associations between dietary intake and plasma pyridoxal-5′-phosphate (PLP) and cofactor stimulation of aspartate aminotransferase in erythrocytes (EAST-AC) among 441 nonvegetarian (aged 65-79) and 32 vegetarian elderly (aged 65-94). EAST-AC was found to be inversely related with intake of vitamin B6 and dietary fiber in bivariate regression analyses. After adjustment for age, intake of energy, protein, and fiber, the intake of vitamin B6 was still inversely related with EAST-AC. The association between EAST-AC and dietary fiber disappeared in the multivariate analysis, whereas total protein intake proved to be positively related with EAST-AC in the multivariate analysis only. The differences between bi- and multivariate analyses are most likely due to the observed interrelationships between intake of vitamin B6, fiber, and protein. It is concluded that dietary fiber does not have a significant impact on the vitamin B6 status among Dutch elderly people, since only protein (positively) and vitamin B6 (inversely) intake appeared to be related with EAST-AC in the multivariate analysis.

ISSN:0731-5724    

DOI:10.1080/07315724.1990.10720375

出版商:Routledge    

年代:1990

数据来源: Taylor

摘要:

Samples of beefsteak, beef liver, haddock, and mushrooms were cooked by two methods: boiling and broiling. Growth and purine metabolism in rats fed diets containing 20% protein (N×6.25) were studied for a period of 26 days. The cooked meats and fish were used as the sole source of dietary protein, while cooked mushrooms provided 5% protein in mushroom-casein diets. Body weight, and food and water intakes were recorded weekly while total urine was collected during the last 6 days of the feeding period. Levels of purine metabolites (uric acid and allantoin) in blood and urine were determined by enzymatic methods and reverse-phase HPLC techniques. Dietary treatments had no significant effects on weight gain and food consumption. Compared with animals fed the casein control diet, rats fed the broiled liver, broiled haddock, and boiled mushroom diets had significantly (p less than 0.05) higher concentrations of serum allantoin, suggesting that uricogenicity of these foods was influenced by the method of cooking. The renal excretion of purine metabolites was significantly correlated with purine intake, the renal excretion of allantoin and uric acid being the highest in rats fed the liver diets.

ISSN:0731-5724    

DOI:10.1080/07315724.1990.10720376

出版商:Routledge    

年代:1990

数据来源: Taylor

摘要:

The relationship between obesity and the digestion of carbohydrates is poorly understood. Data in humans have provided conflicting results. Studies using the obese mouse (C57BL/6Jobob) suggest that obesity is associated with increased activity of intestinal alpha-disaccharidases. To evaluate the developmental pattern of these enzyme activities in obesity, we determined the activity of sucrase and lactase in the small intestine of genetically obese mice (C57BL/6Jobob) and lean littermates at 3 and 10 weeks of age. Sucrase and lactase activities were measured on intestinal homogenates from segments of the small intestine in mice maintained on standard laboratory diets during the postweaning period. Results were expressed as specific activity and total activity per intestinal segment. Obese mice did not differ from lean littermates in body weight at 3 weeks of age, but exhibited increased protein content in the proximal small intestine. Sucrase specific activity was significantly higher in the obese mice at 3 weeks of age in all intestinal segments. Sucrase total activity showed a similar pattern. At 10 weeks of age, body weights of obese mice were substantially greater than the lean littermates. Sucrase specific and total activities were also greater in the obese mice at 10 weeks of age. Lactase specific activity, however, was similar in both obese and lean mice at both ages studied. Lactase total activity was greater in the obese mice, consistent with their greater intestinal mass. These observations demonstrate that changes in the intestinal sucrase activity of the obese mouse precede the development of excessive body weight.

ISSN:0731-5724    

DOI:10.1080/07315724.1990.10720377

出版商:Routledge    

年代:1990

数据来源: Taylor