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Biomedical subjects

M G Schmidt

Publications and source records attributed to M G Schmidt.

27 records · Page 2Linked to original sources
PubMed1979

Patient as volunteer: an assault on chronicity.

By integrating selected former patients into its regular volunteer program, a South Australian state hospital reduced the hospital stays and the readmissions of a large number of the participants who had previously been seen as failures of the community mental health movement. The author describes the program, its benefits, and some limitations and problems, such as an occasional extra burden on ward personnel. The former patients' new roles as volunteers enabled them to get the support they needed from the hospital but through means more acceptable to them. The program also improved their self-esteem and enabled them to engage in more normalizing social relationships.

Adult↗
PubMed1976

Strain-related differences in immunosuppressive effects of Enterobacteriaceae and their lipopolysaccharides on production in rabbits of antibody to enterobacterial common antigen.

Certain polysaccharides have been shown to inhibit the antibody response of rabbits to the common enterobacterial antigen (CA). The present investigation revealed that striking differences exist in the immunosuppressive effects of enteric bacteria and their lipolysaccharides (lps), depending upon CA production by the strains. Mixtures of immunogenic strains (Escherichia coli F2378 [R4], E. coli F470 [R1], or Shigella boydii F3140 [R]) and non-immunogenic CA-producing strains, such as E. coli O1, E. coli O113, Salmonella montevideo, and S. minnesota, as well as the R mutants E. coli F614 (R1), E. coli F757 (R1), and S. typhimurium his 642 (Ra), failed to elicit CA antibodies. In contrast, mixtures of the immunogen and CA-negative strains S. typhimurium his 386 (Ra) and S. minnesota P595 (Re) or R555 (Ra) yielded antibodies in titers similar to those elicited by the immunogen alone. Further, LPS of CA-positive but not of CA-negative strains exerted this immunosuppressive effect. Quantitative studies revealed that LPS of S. minnesota in amounts of 100 mug/ml was strongly immunosuppressive, in amounts of 20 mug/ml slightly effective, and in amounts of 4 mug/ml ineffective. It is postulated that hitherto unknown differences exist, either in composition or in configuration, between LPS obtained from different microorganisms to account for the strain-related differences in immunosuppressive effects and, further, that the immunosuppressive LPS interacts with immunogenic CA.

Animals↗
PubMedDate not supplied

HIV-1 protease regulation: the role of the major homology region and adjacent C-terminal capsid sequences.

The maturation of human immunodeficiency type-1 virions is accomplished through the proteolytic processing of Gag and GagPol precursor proteins by the viral protease (PR). Since virions must be assembled at the cell surface from uncleaved precursor molecules, intracellular activation of PR must be inhibited. We have previously developed a system where the intracellular activity of PR, associated with GagPol, was inhibited by the expression of Gag in trans. The disproportionate synthesis of Gag inhibits the activation of PR in the cytoplasm. Sequences capable of mediating this inhibition were localized to capsid. In this communication, the region of HIV-1 capsid capable of mediating inhibition was further defined and shown to require the major homology region of capsid within Gag.

Amino Acid Sequence↗
PubMedDate not supplied

HIV-1 Rev promotes the nuclear export of unspliced and singly spliced RNAs in a mammalian cell-free export system.

Rev has been shown to promote the export of HIV-1 RNAs from Xenopus oocyte nuclei, but a system to examine the direct effect of Rev on HIV-1 RNA export in mammalian somatic cells does not exist. In this report, the development of a cell-free RNA export system using COS cells is described. This system is capable of examining the movement of RNA from nuclei of COS cells transfected with an HIV-1 proviral construct into reconstituted cytosol from nontransfected cells. A reproducible preparation of nuclei free of residual cytoplasmic RNA is demonstrated. Export of RNA from these nuclei into reconstituted cell-free extracts was saturable and dependent on temperature and energy. Further validation of the system was obtained by confirming that the nuclear export of HIV-1-unspliced and partially spliced RNAs was dependent upon the expression of HIV-1 Rev and that the presence of Rev appeared to decrease the export of an HIV-1-spliced RNA. The system was also able to demonstrate that Rev did not appear to significantly enhance the export of an HIV-1 protease-containing RNA that has been shown to be dependent upon Rev for maximal expression. Consequently, the system appears useful for the examination of parameters of nuclear export of HIV-1 and cellular RNAs.

Animals↗
PubMedDate not supplied

Tumor necrosis factor alpha gene expression in human monocytic THP-1 cells exposed to beryllium.

Chronic beryllium disease, which results from occupational exposure to particulate beryllium, is characterized by the development of lung granulomas and progressive pulmonary fibrosis. Increased production of proinflammatory cytokines (e.g., tumor necrosis factor alpha and interleukin-1 beta) by pulmonary alveolar macrophages occurs in many chronic fibrotic lung diseases and is thought to contribute to the disease process. The purpose of the present study was to investigate cytokine production by human monocytic cells exposed to beryllium in vitro. The results indicated that such cells respond to beryllium ions in the presence of fluoride by accumulation of messenger ribonucleic acid for both tumor necrosis factor alpha and interleukin-1 beta. These findings suggest that inhaled beryllium may directly stimulate the production of these cytokines by alveolar macrophages in vitro.

Beryllium↗
PubMedDate not supplied

Exchange and power in special settings for the aged.

Goffman's model of institutional totality was examined within a social-exchange framework in the boarding and nursing units of two homes for the aged. The power-dependence relationships appeared to be determined by the residents' social resources -- all the assets that enabled them to reward a favor, extort a concession, or do without -- and by the conditions of patienthood that limited their use. Boarders were equally responsive to peer and staff expectations while patients, lacking a cohesive peer group, were more confirming to the demands of staff members, who controlled most of the system's rewards in the nursing units. Efforts to humanize these late-life settings seem unlikely to succeed unless they take into account staff's ability to structure the conditions of negotiation as a base of its power.

Aged↗