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521.
522.
R. P. Cooke T. Riordan D. M. Jones M. J. Painter 《BMJ (Clinical research ed.)》1989,298(6673):555-558
To determine the incidence of secondary meningococcal infection in close family and household contacts of index patients and to review the efficacy of chemoprophylaxis the records of 3256 cases occurring from 1984 through 1987 were examined. Seventeen secondary cases (0.5%) of infection were identified among these groups. The median interval between index and secondary cases was seven weeks. Fourteen secondary cases occurred more than one week after the disease was diagnosed in the index case. Three secondary cases had not received chemoprophylaxis and in another case the infecting strain had acquired resistance to rifampicin. Prophylaxis for the close contacts of 10 out of 11 of the remaining index patients failed to fulfil all the criteria of an optimal regimen. Even after optimal chemoprophylaxis the medical practitioner and the family should be aware of the increased and prolonged risk of secondary meningococcal infection among close contacts of patients with the disease. 相似文献
523.
A sediment quality index (SQI) based on the Canadian Water Quality Index was developed and applied to the assessment of sediment quality in two Great Lakes Areas Of Concern where metals are the primary contaminants of potential concern, Peninsula Harbour (Lake Superior) and Collingwood Harbour (Lake Huron). The SQI was calculated according to an equation incorporating two elements; scope—the number of variables that do not meet guideline objectives; and, amplitude—the magnitude by which variables exceed guideline objectives. Categorizations of sediment quality were developed based on SQI scores. The robustness of the SQI was evaluated through comparison of the relative rankings of sediment quality in the two test areas with results obtained from principle components analysis (PCA) incorporating reference sites, and calculations of hazard quotients (HQs). Trends and rankings in sediment quality determined by the SQI were similar to those calculated using PCA at both test areas. The HQs also appeared to be good indicators of sediment quality. Both the SQI and HQ methods are based on existing Sediment Quality Guidelines, but the SQI had the added benefit of allowing straightforward integration of multiple contaminants. The SQI and PCA analyses appeared complementary in that the SQI incorporated information on the number of variables exceeding guideline values and the degree to which these guidelines were exceeded. The PCA allowed a simple check of the SQI by relating test conditions to regional background. It is recommended that this analysis be performed concurrently with SQI to ensure that non-anthropogenic sources of contaminants (metals in this case) are not considered as representing an anthropogenic hazard. 相似文献
524.
R B Painter 《Mutation research》1985,143(3):113-115
3-Aminobenzamide (3AB), a potent inhibitor of poly(ADP-ribose) synthesis, does not affect the dose response for ionizing radiation-induced inhibition of DNA synthesis in human fibroblasts. If the radioresistant DNA synthesis observed in fibroblasts from patients with ataxia-telangiectasia (A-T) were due to reduced poly(ADP-ribose) synthesis after irradiation, as has been proposed, the response in normal cells incubated with 3AB would have been similar to that observed in A-T cells. Therefore, altered poly(ADP-ribose) synthesis in A-T cells is not solely responsible for their radioresistant DNA synthesis. 相似文献