[Nursing care of children with pneumonia complicated by heart failure in its early stage].
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to Y J Tang.
Explore the source record for details and available documents.
Among a set of frameshift mutagen (ICR-191; Polysciences, Inc.)-induced mutations that confer inability to grow anaerobically with N2O as the sole electron acceptor, one class was found that produced an inactive N2O reductase which lacked copper. All of these mutant strains failed to produce a 61,000-Mr protein located in the outer membrane. This protein, termed NosA, seems not to be responsible for bringing copper into the cell because the mutant strains and their parent were similarly sensitive to the copper content of the growth medium and no intermediate copper concentration in the medium permitted the mutant strains (nosA) to grow anaerobically with N2O as the sole electron acceptor. We conclude that NosA is necessary to insert copper into N2O reductase or to maintain it there.
The role of the capsular polysaccharide in anaphylactic reactions to Cryptococcus neoformans was investigated. Groups of mice were sensitized with viable cells of either a moderately encapsulated strain of C. neoformans or a non-encapsulated variant. Anaphylactic reactions were observed in both groups of mice to a similar extent when challenged with whole cells. Mice sensitized with the encapsulated strain and challenged with homologous polysaccharide showed only mild hypersensitivity symptoms. Mice sensitized with either the encapsulated or the nonencapsulated strain showed cross-reactivity when challenged with killed cells of the heterologous strain. These data indicate that the capsular polysaccharide plays a minor role in anaphylactic reactions to C. neoformans and that the sensitizing antigen is probably located in the cell wall of the yeast.
The polymerase chain reaction was used for the detection of Clostridium difficile, the etiologic agent of antibiotic-associated colitis. An upstream primer identical to a coding region (segment I) of the C. difficile 16S rRNA gene and a downstream primer complementary to a highly conserved region of eubacterial 16S rRNA served to amplify a targeted 270-base-pair fragment of genomic DNA. This technique allowed the detection of as few as 10 C. difficile organisms among 10(6) Escherichia coli bacteria. This level of sensitivity represents a 100-fold increase over that of conventional anaerobic culture. C. difficile was detected in DNA extracted directly from the stools of 23 patients with antibiotic-associated colitis and from those of four patients with diarrhea whose stools had been negative for C. difficile when assessed in a cytotoxicity assay. No amplification products were found in the stools of asymptomatic patients. When detected in stools of symptomatic patients, amplification products of C. difficile were confirmed by Southern blotting with a nonradioactive, horseradish peroxidase-catalyzed, chemiluminescent probing system in which biotin-labeled oligonucleotides were used. This system discriminates between C. difficile and similar organisms, such as Clostridium sordellii and Clostridium bifermentans. The combination of the polymerase chain reaction with enzyme-linked probing results in a faster and more sensitive assay for C. difficile than standard culture.
We identified enterotoxigenic Bacteroides fragilis in stool specimens of patients with inflammatory bowel disease and other gastrointestinal disorders. The organism was detected in 11 (13.2%) of 83 patients with inflammatory bowel disease. Of 57 patients with active disease, 19.3% were toxin positive; none of those with inactive disease had specimens positive for enterotoxigenic Bacteroides fragilis gene sequences.