Objectives: While the importance of exploring and better measuring elements of prenatal care have been noted in the public health literature, the components and timing of such services have been poorly examined for the overall pregnant population and specifically for African-Americans, who traditionally have had higher rates of low birth weight and premature delivery. This study explores the association between patient receipt of selected recommended prenatal care interventions and infant birth weight in a nationally representative sample of African-American women, while controlling for the influence of low birth weight risk indicators. Method: This is a retrospective case-control analysis using survey data of women who delivered normal birth weight, moderate low birth weight, and very low birth weight newborns in 1988. A sample of 3905 African-American women who responded to the 1988 National Maternal and Infant Health Survey is examined based on maternal recall of receipt of six clinical screening procedures and seven health-promotion recommendations. Birth weight measures were obtained from linked 1988 birth certificate data. Results: The initial results indicated that women who do not receive all of the recommended health-promotion advice are more likely to deliver very low birth weight infants than women who receive all of the advice in the content of their prenatal care, after controlling for low birth weight risks (OR = 1.28; 95% CI = 1.01, 1.7). However, when breast-feeding advice is removed from the aggregation of health-promotion advice, the significant effect of advice on very low birth weight is negated. No other significant group variations in the receipt of clinical screening procedures or health-promotion advice for women who gave birth in the remaining birth weight categories are observed. Conclusions: Nationally recommended initial clinical screening procedures and health-promotion advice in prenatal care content do not appear to be associated with a reduction in low birth weight for African-American women. More research is needed to better assess the impact of other antenatal interventions, particularly those given to women with a higher prevalence of poor birth outcomes. 相似文献
Objectives. To confirm the observation that has been occasionally reported in the literature that perinatal mortality rate is lower in ethnic Chinese than in ethnic whites, and to assess the reasons for this lower perinatal mortality rate.
Methods. Secondary‐analysis based on published data.
Results. This exercise demonstrates that the perinatal mortality rate was lower in ethnic Chinese than in ethnic whites. The birth weight distribution in ethnic Chinese was more favourable with reduced births at two extremes of the distribution, and the exposure to risk factors for perinatal death by their mothers was also lower.
Conclusion: Perinatal mortality rate is lower in ethnic Chinese than in ethnic whites, and the lower perinatal mortality rate in ethnic Chinese is probably caused by their favourable birth weight distribution and lower exposure to risk factors of perinatal death by their mothers. 相似文献
Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction
and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose
of γ-rays (0.01 Gy) 4 or 20 hrs prior to high dose γ-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA
fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant
adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low
and high dose γ-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-β-d-ribofuranosylbenzimidazole
(DRFB), respectively during adaptation period, the period from low dose γ-ray irradiation to high dose γ-ray irradiation,
was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated
EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein
and RNA synthesis. 相似文献
In published studies of chronic haemodialysis patients, the frequency of autonomic dysfunction varies widely. One reason for the variation may be the time of testing with respect to time of dialysis. The current study tests the hypothesis that autonomic function — as measured by heart rate responses to the Valsalva manoeuvre (Valsalva ratio) and 30:15 electrocardiogram (ECG) R—R interval to upright posture (postural ratio) — is different when patients are above dry weight (predialysis) than when they are at or below dry weight (postdialysis). The study also reviews available literature to analyze other factors that may affect the results of autonomic testing in this population. A total of 25 chronic haemodialysis patients underwent standard Valsalva and 30:15 R—R interval postural autonomic testing prior to and after haemodialysis. In addition, pre- and postdialysis orthostatic responses were measured and compared with a control population. The 30:15 ratio increased after dialysis (p = 0.001). The Valsalva ratio did not change with dialysis. Out of 25 subjects, seven had an abnormal 30:15 ratio prior to dialysis decreasing to two out of 25 patients postdialysis (p < 0.03). Orthostatic responses predialysis did not differ from those in the control group. Review of the literature shows great variability in definition of normal Valsalva and postural (30:15 R—R interval) ratios. Diabetic patients in the current and prior studies were more likely to have abnormal responses. In conclusion, the prevalence of autonomic dysfunction in chronic dialysis patients as determined by Valsalva and 30:15 ECG postural ratios may be influenced by the following factors: when subjects are studied with respect to their dialysis treatment; the number of subjects with diabetes; and the cut-off point used to define abnormal test results. Abnormal Valsalva ratios are less frequent when measured postdialysis. 相似文献