Biomedical subjects
Publications and source records attributed to J Bruce.
A total of 203 samples of faeces from 124 cows was examined for the presence of Yersinia enterocolitica and related species by a variety of isolation procedures. Cold enrichment at 5 degrees C for three weeks, followed by plating on cefsulodin-irgasannovobiocin agar yielded Yersinia species most frequently. Yersinia enterocolitica or related species were isolated from 50% of the cows.
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A high proportion of T cell clones derived from bulk cultures selected to M1s a,d determinants were found to have joint specificity for allo-H-2 determinants, and vice versa. Significantly, the patterns of H-2 alloreactivity shown by clones selected to M1sa,b determinants appeared to be random. The possible implications of these findings are discussed.
(CBA x B6)F1 (Iak x Iab) T cells were activated to sheep erythrocytes in irradiated F1 mice in the presence of various monoclonal anti-Ia reagents and then tested for their capacity to collaborate with B cells from B10.BR (I-Ak, I-Ek) (kk), B10.A(4R) (kb), and B10 (bb) mice. Anti-I-Ak antibodies blocked the generation of help for B10.A(4R) B cells, but not B10.BR or B10 B cells. An anti-I-Ab antibody blocked help for B10 B cells, but not for B10.BR or B10.A(4R) B cells. An antibody (Y-17) specific for I-Ak/Ek and I-Ab/Ek molecules, but not for I-Ak or I-Ab molecules, failed to impair the generation of help for B10.BR, B10.A (4R), or B10 B cells. In marked contrast to injecting each antibody separately, a mixture of anti-I-Ak and anti-I-Ak,b/Ek (Y-17) antibodies virtually abolished the generation of help for B10.BR B cells. A mixture of anti-I-Ak and anti-I-Ab antibodies effectively blocked help for (4R x B10)F1 B cells, i.e., cells expressing hybrid I-A molecules. These two antibodies only marginally impaired help for (CBA x B6)F1 B cells. To block help for (CBA x B6)F1 B cells required selection in the presence of a cocktail of anti-I-Ak, anti-I-Ab, and anti-I-Ak,b/Ek antibodies. The implications of these findings are discussed.
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A description is given of a rat anti-mouse hybridoma antibody, JIId, which reacts with erythrocytes, neutrophils, greater than 90% of thymus cells, and most B cells. JIId does not have detectable activity for mature T cells, pluripotential stem cells, platelets, or cells of the monocyte-macrophage lineage. Although the JIId antigen is present on 90 to 95% of typical small B lymphocytes, pretreatment of spleen cells with JIId plus complement has no effect on secondary IgG antibody responses; by contrast, primary IgM responses and proliferative responses to lipopolysaccharide are substantially reduced. Unlike the precursors of IgG antibody-producing cells (AFC), IgG AFC per se are strongly JIId-positive. Rapid acquisition of the JIId antigen also applied to the early progeny of pluripotential stem cells.
There are today some 200 women's health centers in the United States providing information and, in many cases, direct health and family planning services to women in a manner responsive to their needs and preferences, and that involves them in the design and provision of services. This approach to delivering services was specifically recommended by the International Conference of Family Planning in the 1980's held in Indonesia in April 1981. in addressing the challenges facing family planning programs in the decade ahead, the conference noted that in many parts of the world, women often have little control over decisions related to their own fertility. Furthermore, low levels of acceptance and use of family planning, which are characteristic of many programs, often reflect a failure to design and provide services in a manner that is responsive to the needs and perceptions of the users. The conference called for measures to improve the status of women, and recommended that women be involved in all aspects of program design, management, policymaking, and provision of services. In this special report, Judith Bruce describes how women-oriented services are designed and provided at one of the women's health centers, The New hampshire Feminist Health Center.
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Lung function among 599 white male employees of a southeastern Tennessee copper mine/smelter operation was compared according to smoking history and occupational experience. The job categories compared included employees with work histories in low sulfur dioxide [SO2] environments (both underground mining and non-mining), in high SO2 exposure work areas, and in those with transient exposure to SO2. Miners with low SO2 exposure were found to have lower lung function indices (both FVC AND FEV1) than did employees in other job categories. Smoking history was strongly associated with low FEV1. After adjusting for smoking history, cumulative long-term exposure to SO2 was not demonstrated to contribute to decreased lung function.
Information was sought on whether B cells undergo abnormal differentiation in F1 leads to parent chimeras (irradiated parental-strain mice reconstituted with F1-hybrid bone marrow cells). As assessed by collaborative responses to sheep erythrocytes in vivo, three different types of T cells restricted to interaction with strain a H-2 determinants were shown to collaborate as effectively with heterologous F1 leads to b chimera B cells as with homologous F1 leads to a chimera B cells. This applied to both primed and unprimed B cells, to IgM- and IgG-antibody formation and to production of Ig allotype. Thus, unlike T cells, B cells from F1 leads to parent chimeras behaved indistinguishably from normal F1 B cells. F1 leads to parent chimeras were also examined for their capacity to present antigen to normal F1 T cells in vivo. The results suggested that the antigen-presenting cells in these chimeras were no different than in normal F1 mice. Collectively these data imply that, at least in the situation studied, raising F1 stem cells in a parental-strain environment has a marked effect on T-cell specificity but does not discernably influence the differentiation of B cells or macrophage-like cells.
Administration of 4 nitro-4' isothiocyano-diphenylamine (CGP 4540, amoscanate) to two nonhuman primates, Macaca mulatta and Cebus apella, resulted in the appearance of mutagenic material in the urines of these animals. Mutagenic metabolites of this drug could also be detected in the urines when the drug was administered to primates infected with Schistosoma mansoni and Schistosoma japonicum. As observed previously in mice, the mutagenic activation of amoscanate can be prevented in primates by coadministration of a single oral dose of erythromycin with no concomitant reduction in antischistosomal activity. The protective effect of erythromycin was confirmed in several crossover experiments. This dissociation of mutagenic from chemotherapeutic effects provides an opportunity to reduce serious potential long-term risks of this antischistosomal drug.
Cells of the beige mouse contain abnormally large lysosomes and show enhanced capping of concanavalin A. It has been suggested that these phenomena may be secondary to a defect in microtubule polymerization. We have examined the cytoskeleton of beige mouse cells by indirect immunofluorescence and find the number and distribution of microtubules and actin cables to be indistinguishable from those of normal control cells.
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Within the bacterial ribosome a large number of specific protein and rRNA interactions appear to be required for assembly of the particle and its subsequent function in protein synthesis. In this communication it is shown that it is possible to isolate cyanogen bromide digestion products from ribosomal 30S protein S8 which will interact stoichiometrically with 16S rRNA. In addition to this a small binding polypeptide was generated from S8-16S rRNA complexes which were treated with proteinase K. The digestion of the complex yields a "protected" fragment of protein S8 which binds to 16S-rRNA. The isolated fragment will reassociate with 16S rRNA. It is not displaced by other 30S ribosomal proteins and blocks the binding of intact S8 to 16S rRNA. The size the possible structure of the S8 protein binding site are discussed and compared with the binding of cyanogen bromide digestion products which bind to 16S rRNA.
Conditions are described for optimal stimulation in vitro of lymphocytes from rats primed in vivo with syngeneic MuLV-G leukaemia cells. Cultures generate effector cells which show high cytotoxic activity against leukaemic cells. Specific stimulation can be obtained with leukaemic cells and with disrupted MuLV. Leukaemic cells, normal spleen cells and the viron internal protein p30 competitively inhibit effector cells, but purified virus exerts non-specific inhibition. These findings are interpreted as supporting the hypothesis that virion antigens constitute a major target of anti-tumour cytotoxic immunity.
The interaction between ribosomal proteins of the 30s subunit with intact 50s subunits was investigated. Experiments with mixtures of total 30s proteins indicated that several 30s proteins including protein s4 would form a stable complex with 50s subunits. Further work with pure s4 indicates that this protein binds stoichiometrically to the 50s subunits, probably through protein-nucleic acid interaction. The possible significance of this interaction is discussed.
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