Phenotypic and proliferative properties of Schwann cells from nerves of diabetic patients.

The phenotypic (morphologic and antigenic) properties and mitotic index of cultured Schwann cells obtained by dissecting nerves from six diabetic patients were studied. These features were compared with those of Schwann cells cultured in vitro from six normal control nerves. Preservation of the specific antigenic properties of cells, identified with rabbit antiserum as bovine protein S-100, was documented by immunofluorescence with monoclonal antibodies against laminin, fibronectin, histocompatibility antigens HLA-A, B, C and -DR, HNK-1 antigen and the human receptor for nerve growth factor. The cell proliferation index was assessed by incorporation of bromodeoxyuridine. The results of the study showed that the mitotic capacities of Schwann cells from diabetic nerves cultured in vitro remained comparable with those of normal control cells. As regards phenotypic characteristics, no modifications were detectable by immunofluorescence. These findings suggest that the phenomena of demyelination and remyelination, sometimes with onion bulb features, which can be observed in some cases of diabetic neuropathy, are not due to a primary dysfunction of the Schwann cells but are secondary to axonal degeneration.     

Transmission of Mycobacterium tuberculosis in a California State Prison, 1991.

OBJECTIVES: An investigation was conducted to determine whether ongoing transmission of Mycobacterium tuberculosis was occurring in a California state prison. METHOD: Prison pharmacy records were used to identify cases of active tuberculosis (TB). RESULTS: Ten of the 18 cases of active TB treated at the facility during 1991 were diagnosed at the prison that same year (an incidence of 184 per 100,000). Three inmates were infectious for a total of 7 months while imprisoned. The prevalence of TB skin test-positivity among inmates was 30%, and the incidence of new infection attributable to incarceration was 5.9 per 100 inmates per year. CONCLUSIONS: Transmission of M. tuberculosis may be occurring in the California prison system.     

Split tolerance in chimeric GVH mice

Abstract The i.v. inoculation of parental spleen cells into unirradiated adult F1 hybrid mice results in a graft-versus-host reaction (GVHR). In the strain combination B10D2±(B10.BRx B10.D2) F1, this reaction is associated with thymic injury and transient but profound cellular immune deficiency. We further analysed the immune status of these mice 60 days after GVHR induction. Phenotypic studies of spleen cells showed that these mice were re-populated with parental lymphocytes resulting in a high degree of chimerism (85%). At this time, the mice looked healthy and recovered a normal cytotoxic T cell response (CTL) against allogeneic cells. GVH chimeric splenocytes were unresponsive against F 1 hybrid cells in mixed lymphocyte culture (MLC), but exhibited anti-F1 CTL reactivity. We also analysed the anti-F 1 reactivity of these mice in vivo. GVH chimeric splenocytes were unable to induce GVHR after injection into a new F1 hybrid and F1 GVH mice specifically rejected F1 bone marrow (BM) cells after lethal irradiation. Grafting a neonatal parental thymus prevented the rejection of F1 BM cells and restored CTL alloreactivity. It is concluded that the chimeric state induced by GVHR is associated with a split tolerance and that a radiosensitive thymic-dependent mechanism is involved in maintaining self-tolerance in these mice.     

Effect of physiotherapy on sickness absence in industry: a comparative study.

A cross-sectional comparative study was carried out in two chemical manufacturing plants in order to ascertain the effect of an occupational physiotherapy service on absence attributed to sickness. There was no overall effect on total sickness absence rates in this study, but a possible reduction in short-term sickness absence was noted. Changes in management attitudes to absence attributed to sickness at the comparison site caused a significant reduction in short-term absences. It is concluded that physiotherapy in an occupational setting has little effect on sickness absence compared to management attitudes, but the unquantifiable benefits, such as increased employee mobility, better industrial relations and employee morale may be significant benefits, worthy of further study.