To determine whether data available to physicians in the emergency room can accurately identify which patients with acute chest pain are having myocardial infarctions, we analyzed 482 patients at one hospital. Using recursive partitioning analysis, we constructed a decision protocol in the format of a simple flow chart to identify infarction on the basis of nine clinical factors. In prospective testing on 468 other patients at a second hospital, the protocol performed as well as the physicians. Moreover, an integration of the protocol with the physicians' judgments resulted in a classification system that preserved sensitivity for detecting infarctions, significantly improved the specificity (from 67 per cent to 77 per cent, P less than 0.01) and positive predictive value (from 34 per cent to 42 per cent, P = 0.016) of admission to an intensive-care area. The protocol identified a subgroup of 107 patients among whom only 5 per cent had infarctions and for whom admission to non-intensive-care areas might be appropriate. This decision protocol warrants further wide-scale prospective testing but is not ready for routine clinical use.
Using standard procedures, aerobic plate counts (APC), total and fecal coliform most probable number (MPN) determinations, and analyses for Salmonella, Arizona, Shigella and Edwardsiella tarda were performed on 335 fresh and 342 frozen sample units of channel catfish. APC values for 93.0% of the fresh and 94.5% of the frozen samples were
The behavior of microorganisms was studied in mung beans and alfalfa seeds before and after germination in modified, commercially available bean-sprouting kits. The microorganisms were enumerated by the aerobic plate count (APC) and by total yeast and mold count procedures. Salmonella species were artificially inoculated into selected samples and were enumerated by the most probable number (MPN) method. After germination of the beans or seeds into mature sprouts, significant increases were noted in APCs and in MPN values of Salmonella species. Although counts of yeasts and molds did not increase significantly after germination, these samples showed an increase in toxic Aspergillus flavus and potentially toxic Alternaria species. The presence of toxic Penicillium cyclopium molds also increased substantially in 5 samples of a single brand of mung beans. Analysis of selected sprout samples, however, showed no presence of aflatoxin.
An assay for the enzyme glucuronidase was used to determine the presence of Escherichia coli in selected, naturally contaminated high moisture foods. Raw pork sausage, ground turkey, and ground beef were inoculated into tubes containing the substrate 4-methylumbelliferyl beta-D-glucuronide (MUG) in lauryl tryptose (LT) medium. After incubation at 35°C for 24 h, the inoculated LT-MUG tubes were examined under longwave ultraviolet light for the presence of a fluorogenic glucuronidase end product. A fluorescing tube indicated the presumptive presence of E. coli. The 10 day most probable number method of the AOAC and the LT-MUG procedure gave comparable recoveries of E. coli.
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