OBJECTIVE: To investigate whether the sex ratio of children varies between fathers of different occupations. METHODS: The sex ratio (the ratio of the number of boys to the number of girls at birth) was calculated in relation to paternal occupation in the cohort of all 253,433 live births in Cumbria, north west England, from 1950-89. Exact binomial confidence intervals were used to estimate whether the sex ratio in each occupational category was significantly different from that for the rest of the cohort. RESULTS: There were fewer occupational categories with significantly different sex ratios at the 5% level than expected by chance alone, assuming the same binomial distribution of sexes at birth within each paternal occupation. CONCLUSIONS: Significant variation of the sex ratio with fathers' occupations was not found. There is some evidence that the sex ratio shows less variance than expected under a binomial model which assumes independence of the sex of each child; a possible explanation of this may be parental preference for limiting family size after children of both sexes have been born or some other factor which results in children within a family being more likely to be of both sexes rather than the same sex. 相似文献
A cross-sectional comparative study was carried out in two chemical manufacturing plants in order to ascertain the effect of an occupational physiotherapy service on absence attributed to sickness. There was no overall effect on total sickness absence rates in this study, but a possible reduction in short-term sickness absence was noted. Changes in management attitudes to absence attributed to sickness at the comparison site caused a significant reduction in short-term absences. It is concluded that physiotherapy in an occupational setting has little effect on sickness absence compared to management attitudes, but the unquantifiable benefits, such as increased employee mobility, better industrial relations and employee morale may be significant benefits, worthy of further study. 相似文献
Background. Leukocytes are associated with myocardial injury during reperfusion after ischemia. Short periods of leukocyte depletion during reperfusion result in persistent attenuation of postischemic myocardial dysfunction.
Methods. Leukocyte depletion was examined in a canine model of regional myocardial ischemia and reperfusion. The extracorporeal circuit and cardioplegia circuits underwent leukocyte depletion by mechanical filtration. Animals were instrumented for baseline global function before 90-minute occlusion of the left anterior descending coronary artery. Global function during ischemia and at 5, 30, 60, and 90 minutes after a 60-minute cardioplegic arrest using continuous blood cardioplegia was assessed in leukocyte-depleted (n = 9) and control (n = 10) groups.
Results. No significant difference between groups was seen for systemic leukocyte counts, global function, or water content. Endothelial function was significantly protected as assessed by response to both calcium ionophore (endothelial-dependent, receptor-independent relaxation: leukocyte-depleted, 72% ± 19% of endothelin-induced constriction versus control, 46% ± 14%; p < 0.05) and acetylcholine (endothelial-dependent, receptor-dependent relaxation: leukocyte-depleted, 83% ± 11% versus control, 44% ± 15%; p < 0.05).
Conclusions. Leukocyte-mediated endothelial reperfusion injury can be attenuated by leukocyte depletion during reperfusion. 相似文献
Hypertension after cardiac surgery is common and requires accurate control by carefully regulated infusions of drugs such as sodium nitroprusside. A microprocessor-based controller has been designed to close the loop between the blood pressure response and the infusion rate of a hypotensive drug. This system has been refined by computer simulation of the blood pressure response to sodium nitroprusside and by experience gained in using the controller in eleven patients in the early recovery period after cardiac surgery. The controller was able automatically to maintain blood pressure within 10% of a specified value. Provision of sophisticated safety features in automatic drug infusion controllers is essential for patient protection. 相似文献
Epidermolysis bullosa is a group of dermatologic disorders with varied inheritance patterns having the common manifestation of blister or bulla formation after minor trauma. Sixteen patients with the disease had the following radiographic manifestations: esophageal stricture (16), fecal impaction (six), vaginal stenosis (one), epithelial bridging and fusion of the digits (six), and aspiration changes in the lungs (two). Esophageal strictures involved the pharynx or cervical esophagus in eight cases and were multiple in five; they ranged in length from 2 mm to 15 cm and tended to progress over time. The findings of esophageal stricture, particularly when multiple and involving the proximal esophagus, and/or the presence of distal phalangeal atrophy with soft-tissue webbing suggest the diagnosis of epidermolysis bullosa. 相似文献
A representative sample of 1,367 employed men and women in Detroit responded to questions about drinking practices and symptoms of depression. After controlling for age, education, family income, marital status, medication use, fathers' drinking, and other variables, increased quantity of alcohol consumed per drinking occasion was associated with increased depression symptoms in the sober state among men and women. Depression symptoms may be one of a group of not fully identified drug after-effect disorders involving psychological functioning. 相似文献
A 73-year-old man with severe chronic obstructive pulmonary disease and cor pulmonale developed an intermittent right bundle branch block (RBBB) during mechanical ventilation. The appearance and disappearance of his RBBB was temporally associated with each positive pressure breath. Intermittent RBBB is a previously undescribed complication of positive pressure ventilation. 相似文献