CD4 T lymphocyte activation in BLV-induced persistent B lymphocytosis in cattle.

Bovine leukemia virus (BLV) is an oncogenic retrovirus in the human T cell leukemia virus family. BLV infects B lymphocytes and induces a nonmalignant persistent lymphocytosis (PL) and leukemia/lymphoma in cattle. There is evidence that CD4 T lymphocytes are activated during BLV infection and promote the development of PL. How CD4 T lymphocytes are activated by BLV infection is not known. We observed that CD4 T lymphocytes from PL cattle proliferated in the presence of autologous, irradiated peripheral blood mononuclear cells (PBMC), whereas no proliferation occurred in cell cultures from BLV-infected non-PL cattle. Proliferation required direct contact with metabolically active irradiated PBMC but was not associated with viral protein expression or inhibited by antibodies to BLV. Unexpectedly, B lymphocytes alone failed to account for the irradiated PBMC stimulation of CD4 T lymphocytes. These observations and the magnitude of the proliferative response suggest that activation is polyclonal and involves mechanisms other than BLV antigen-specific stimulation.

Medical services use by patients before and after detoxification from benzodiazepine dependence.

OBJECTIVE: The authors examined use of medical and mental health services before and after detoxification among a group of patients detoxified from benzodiazepines to see if the data suggested a reduction in service use and costs after detoxification, the so-called offset effect observed for treatment of alcohol and mental disorders. METHODS: Through a medical record review, information was collected about medical service use for patients aged 40 and older who were detoxified from benzodiazepines at Scott and White Clinic and Hospital between 1987 and 1991. RESULTS: Among the 76 patients, medical and mental health outpatient visits fell from an average rate of 25.4 visits per year before detoxification to 4.4 per year after detoxification. For the 44 patients with at least one inpatient stay besides the admission for detoxification, the mean number of inpatient days remained constant at three days per year before and after detoxification. CONCLUSIONS: Although a retrospective record review suffers from a range of limitations, the findings suggest that detoxification from benzodiazepines may be effective in reducing use of outpatient medical and mental health services and presumably in reducing costs of care.