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排序方式: 共有10000条查询结果,搜索用时 31 毫秒
981.
982.
Eight-eight female weanling Sprague-Dawley rats were fed diets containing either 650 or 150 mg magnesium/kg diet and 7.0 or 3.5 mg pyridoxine-HCl/kg diet, in a 2 x 2 factorial arrangement, during growth, gestation, and lactation. The objective of the study was to determine whether concurrent dietary deficiencies of magnesium and pyridoxine were synergistic, additive, or antagonistic with regards to effects on reproductive performance, growth, and development of offspring, and tissue content of magnesium and calcium. Body weight of dams and pups was not different between groups until day 9 of lactation, at which point those animals in either low magnesium group weighed less than the other. Litter size and birth weight were not different. Development, as measured by timing of unfolding of the external ear, opening of both eyes, and clinical emergence of incisors, was delayed in pups from litters in the low magnesium groups. A synergistic effect on delay of onset of ear unfolding by deficiency of both magnesium and pyridoxine was observed. Calcium content of heart and kidney from dams was increased in the low magnesium groups. Renal calcium was not further increased by the level of pyridoxine deficiency in this study. The calcium to magnesium ratio in heart from pups was higher in those from litters in the low magnesium and pyridoxine group than in the others. Results indicate that simultaneous deficiencies of magnesium and pyridoxine may impair function synergistically. Because these two nutrients are often reported to be presented in inadequate amounts in diets of women in their reproductive years, the potential exists for impaired reproductive success. 相似文献
983.
G J Wintemute J F Kraus S P Teret M A Wright 《American journal of preventive medicine》1988,4(6):343-348
Previous epidemiological studies of drowning in the United States have dealt primarily with children. The epidemiology and prevention of drowning in adulthood may be very different. To test this general hypothesis, we analyzed the 293 drownings occurring among Sacramento County residents 20 years of age and above during 1974 to 1985. Drowning rates were highest for men 20-29 years of age (11.5 per 100,000 population) and blacks (7.5 per 100,000 population). Swimmers, boaters, and motor vehicle occupants were most frequently represented. Alcohol use was involved in 48% of cases overall and 77% of those involving motor vehicle occupants. A history of seizure disorder was another contributing factor. Important differences do exist in drowning epidemiology between children and adults. Our results suggest that preventing drowning will be more problematic among adults than among children. The study was also used to test the sensitivity of two commonly used methods of case ascertainment for cases in Sacramento County. A manual review of coroner's records had a sensitivity of 96%. A computerized review of death certificate data from the state's vital statistics data base had a sensitivity of 79%. The sources and implications of these differences are discussed. 相似文献
984.
Falls among the elderly: epidemiology and prevention 总被引:1,自引:0,他引:1
G S Sorock 《American journal of preventive medicine》1988,4(5):282-288
Harmful psychological and physical consequences may result when elderly people fall. I summarize the epidemiology of falls among elderly people and focus on three potentially remediable causes of falls: reduced peripheral neurosensation, the use of psychoactive medication, and environmental hazards. From 1960 to 1980, death rates from falls among white persons 75 years of age and older have decreased by more than 50%. Fall rates among community-dwelling elderly people increase with age and are greater for women than men. The death rates from falls, however, are now greater for men than women. Reduced peripheral neurosensation in the lower extremities may be a significant cause of falls among the elderly. Recreational walking or physical therapy may improve these deficits and lead to fewer falls. The use of psychoactive medications, most commonly benzodiazepine sedatives, is possibly associated with an increased risk of falls and hip fractures; greater caution in the use of these medications is warranted. The elimination or redesign of steps and curbs and the provision of hand railings and walking aids may be the most effective environmental approaches to preventing falls. These conclusions need further study in community-dwelling elderly populations. 相似文献
985.
In the doubly-labelled water (2H2(18)O) method for the measurement of carbon dioxide production rate in man, single exponential disappearance curves for 2H2O and H2(18)O in body water are used; the precision with which the slopes and intercepts of the curves are estimated determines the precision of the estimate of carbon dioxide production rate. In studies with infants, and in computer simulations, the effect of different experimental regimes on the overall precision of the carbon dioxide production estimate was investigated. When the number of data points used was progressively reduced by shortening the total observation period from 7 d (about 3 biological half-lives for the isotopes) to 1 d there was a deleterious effect on precision and in the infants there was an upward bias in the values for carbon dioxide production. When the number of data points was reduced by removing points from the middle of the exponential curves with the maintenance of the 7-d experimental period, precision was also reduced but by less than in the former procedure and there were no consistent trends in the average values for carbon dioxide production. 相似文献
986.
Correlation between concentrations of humoral antibodies and vitamin D nutritional status: a survey study 总被引:2,自引:0,他引:2
S H Sedrani 《European journal of clinical nutrition》1988,42(3):243-248
The vitamin D nutritional status and the plasma concentrations of IgG, IgA, IgM and total immunoglobulins were determined in 2052 Saudi subjects. It was observed that females had significantly lower 25-hydroxyvitamin D levels than males and children had lower levels than adults. The mean levels of IgG and IgM were significantly higher in females than in males and those in adults higher than in children. There was a highly significant positive correlation between the concentrations of the circulating form of vitamin D, 25-OHD, and IgG levels in the overall population, in children and in adults. When these groups were classified into males and females the correlation was significant only for females. The significance and importance of this correlation between vitamin D nutritional status and IgG is as yet unknown. The possible clinical relevance of this study's findings are discussed. 相似文献
987.
988.
K A Burkman R W Gaines S R Kashani R D Smith 《Archives of physical medicine and rehabilitation》1988,69(2):132-134
Herpes zoster probably occurs more often than generally thought. Since it produces a radicular distribution of pain, it should be included in the differential diagnosis of radiculopathy. A case is presented in which evaluating the radicular low back pain before the characteristic rash appears was misleading. Careful history-taking concerning the exact nature of the pain and sensory changes is needed to differentiate between zoster and radiculopathy, if no rash is evident. 相似文献
989.
990.