Role of complement in Mycobacterium avium pathogenesis: in vivo and in vitro analyses of the host response to infection in the absence of complement component C3.

We investigated the importance of the host complement system in the pathogenesis of disease mediated by the intramacrophage pathogen Mycobacterium avium. Mycobacteria opsonized with complement are efficiently ingested by macrophages through various complement receptors. Furthermore, unlike other bacteria, mycobacteria can activate both the alternative and classical complement pathways in the absence of specific antibodies. Therefore, to examine the role of complement in the mycobacterial infection process in vivo, mice deficient in complement component C3 were infected with M. avium. Surprisingly, C3-deficient mice infected intravenously with M. avium displayed no difference in bacterial burden or granulomatous response compared to wild-type control mice. C3-sufficient mice and C3-deficient mice were equally susceptible to infection by M. avium regardless of the genotype at the bcg locus, a locus known to confer susceptibility to infection with intracellular pathogens. In vitro studies using mouse bone marrow-derived macrophages resulted in significant M. avium invasion of macrophages in the absence of C3; however, the kinetics of infection were delayed compared to complement-mediated invasion. The data indicate that complement does not play an essential role in mediating M. avium infections in the mouse and suggest either that other invasion mechanisms can compensate for the absence of complement-mediated entry or that complement is not a major mycobacterial opsonin in vivo.

Graduate nursing students' attitudes toward gay and hemophiliac men with AIDS.

Subjects were 180 registered nurses enrolled in a master's nursing program. By random assignment, each read one of six versions of a vignette about a male patient. Vignettes differed in terms of patient's diagnosis (AIDS of unspecified origin, AIDS in a hemophiliac infected by blood transfusion, and leukemia) and sexual preference (gay or heterosexual). Nurses evaluated the patient on two scales, one involving judgments of patients and the other concerning willingness to interact socially with them. The hemophiliac/AIDS and leukemia patients were judged significantly less responsible for and less deserving of their illnesses than was the patient with AIDS of unspecified origin (p less than .001). However, all three diagnostic categories were considered equally deserving of the best possible care. Both categories of AIDS patients were stigmatized in terms of certain social interactions. There was also some weak evidence of antigay bias. Implications for theory and practice are discussed.

Nutrition and the homeless person.

Homeless persons include men, women, and children who are among the poorest of America's poor. A review is provided of the eating patterns of the homeless, their special nutritional problems, and controversial nutritional issues involving them. Also discussed are ways in which community health nurses (CHNs) can (a) help upgrade the nutritional standards of community-based shelters and other facilities which feed the homeless, and (b) provide suggestions to such food providers to improve the social climate during mealtimes.

A survey of doctorally prepared academic nurses on qualitative and quantitative research issues.

A nationwide mail survey of 400 doctorally prepared nurses in academia yielded 251 usable questionnaires. Fifty-five percent had doctoral research preparation classifiable as primarily (or entirely) quantitative (Qn), 11% as qualitative (Ql), and 33% as combined qualitative-quantitative (Combined). Two separate scales assessed the nurses' positions on qualitative-quantitative issues. The Ql and Combined research preparation groups held significantly more favorable positions toward qualitative methodology than the Qn group. However, these differences did not indicate polarization on this issue. The Qn group also exhibited a favorable position on qualitative methods, though to a lesser degree. All three groups favored combined qualitative-quantitative doctoral research preparation as ideal and advocated increased coverage of qualitative research in nursing journals.