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991.
There is debate about the possible deleterious effect of excessive vitamin A exposure on fracture risk. In this nested case control study in older women (312 cases and 934 controls), serum retinol, retinyl palmitate, and beta-carotene were not associated with fracture risk, and there was no evidence of excess risk with multivitamin or cod liver oil supplementation. INTRODUCTION: Recent studies have suggested that higher vitamin A intake may account for a component of fracture risk within the general population and that supplemental vitamin A may be harmful even within recommended limits. No studies have examined the relationship between biochemical retinol status and fracture in older women. MATERIALS AND METHODS: We examined serum retinol, retinyl palmitate, and beta-carotene as predictors of incident hip and other fractures in a large prospective study of British women over the age of 75 years (n = 2606, 312 incident osteoporotic fractures, 92 incident hip fractures; mean follow-up duration, 3.7 years). Fasting blood samples (9:00-11:00 a.m.) were collected at baseline. Using a case-control design (three controls per case), serum retinol, retinyl palmitate, and beta-carotene were assessed as univariate predictors of incident osteoporotic fracture or hip fracture. Baseline BMD at the total hip, age, 25(OH)D, serum beta Crosslaps, bone-specific alkaline phosphatase, weight, height, and smoking were considered as covariates in a multivariate model. RESULTS: Serum retinol, retinyl palmitate, and beta-carotene were not significant univariate predictors of either hip fracture or any fracture (all p > 0.05; Cox proportional hazards regression). For all osteoporotic fractures, the hazard ratio (HR) was 0.92 (95% CI, 0.81-1.05) per 1 SD increase in serum retinol. Risk of any osteoporotic fracture was slightly less in the highest quartile of serum retinol compared with the lowest quartile (HR, 0.85; 95% CI, 0.69-1.05; p = 0.132) There was a tendency for increased serum retinol to predict benefit rather than harm in terms of BMD (r = 0.09, p = 0.002). Multivitamin or cod liver oil supplementation was associated with a significantly lower risk of any fracture (HR, 0.76; 95% CI, 0.60-0.96; p = 0.021). In multivariate analysis, only age, total hip BMD, and weight were associated with fracture risk (p < 0.05). CONCLUSIONS: We found no evidence to support any skeletal harm associated with increased serum indices of retinol exposure or modest retinol supplementation in this population.  相似文献   
992.
OBJECTIVE--To assess whether fetal heart rate in early and late pregnancy relates to size at birth. DESIGN--Prospective study of fetal heart rates in early and late pregnancy. SETTING--Princess Anne Hospital, Southampton. SUBJECTS--63 primigravid women. MAIN OUTCOME MEASURES--Anthropometric measurements made on the newborn infant. RESULTS--There were no differences in heart rate between the sexes at 18 weeks gestation but by 36 weeks the boys had rates which were 4.4 beats lower than those of the girls. Higher fetal heart rate at 18 weeks was associated with lower ponderal index, smaller head circumference and smaller mid-arm circumference. There were no trends in fetal heart rate at 36 weeks with any birth measurements. CONCLUSION--Babies born at term who have a pattern of neonatal measurements which reflect growth retardation have raised heart rates in early pregnancy. Influences which impair fetal growth appear to take effect early in gestation.  相似文献   
993.
A case-control study of acute appendicitis and diet in children.   总被引:1,自引:1,他引:0       下载免费PDF全文
The diets of 53 Southampton children who had had appendicitis were compared with those of two sets of age-sex matched controls using a seven-day weighed food record. One set of controls comprised classmates of the cases; the other was a random sample of all schoolchildren in the city. The cases weighed less and were shorter in height; they had lower intakes of energy, all the main nutrients and water. The differences in weight and water intake were statistically significant. Low water intake was identified as a risk factor independent of other factors. Consumption of dietary fibre from cereals and vegetables in relation to total energy intake and body weight was similar in cases and controls.  相似文献   
994.
995.
A simple technique permitting long term 31P magnetic resonance spectroscopy of cultured mammalian cells is described. Cells are encapsulated in calcium alginate gels and perfused with a new phosphate-fre medium designed for maintenance of high cell viability. Intracellular pH and beta-NTP/Pi ratios, studied in three cell types, remained stable over a 16-20 h NMR monitoring period. The techniques described may be useful for monitoring cell metabolism with a variety of cell types.  相似文献   
996.
The validity and cost-effectiveness of three methods for detecting medication errors were examined. A stratified random sample of 36 hospitals and skilled-nursing facilities in Colorado and Georgia was selected. Medication administration errors were detected by registered nurses (R.N.s), licensed practical nurses (L.P.N.s), and pharmacy technicians from these facilities using three methods: incident report review, chart review, and direct observation. Each dose evaluated was compared with the prescriber's order. Deviations were considered errors. Efficiency was measured by the time spent evaluating each dose. A pharmacist performed an independent determination of errors to assess the accuracy of each data collector. Clinical significance was judged by a panel of physicians. Observers detected 300 of 457 pharmacist-confirmed errors made on 2556 doses (11.7% error rate) compared with 17 errors detected by chart reviewers (0.7% error rate), and 1 error detected by incident report review (0.04% error rate). All errors detected involved the same 2556 doses. All chart reviewers and 7 of 10 observers achieved at least good comparability with the pharmacist's results. The mean cost of error detection per dose was $4.82 for direct observation and $0.63 for chart review. The technician was the least expensive observer at $2.87 per dose evaluated. R.N.s were the least expensive chart reviewers at $0.50 per dose. Of 457 errors, 35 (8%) were deemed potentially clinically significant; 71% of these were detected by direct observation. Direct observation was more efficient and accurate than reviewing charts and incident reports in detecting medication errors. Pharmacy technicians were more efficient and accurate than R.N.s and L.P.N.s in collecting data about medication errors.  相似文献   
997.
目的:评价开放手术稳定脊柱(脊柱融合)与强化康复训练治疗慢性下腰痛的临床效果。  相似文献   
998.
999.
1000.
Small pulmonary lesions detected at CT: clinical importance   总被引:27,自引:0,他引:27  
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