Resistance to mycobacteria in mice treated with fractionated total lymphoid irradiation (TLI) and in mice reconstituted with allogenic bone marrow cells following radiotherapy.

The increased clinical use of total lymphoid irradiation (TLI) as an immunosuppressive adjunct in transplantation suggested the need for determining the effects of TLI on the in vivo susceptibility of animals to infections controlled by cell-mediated immunity. TLI-treated, TLI-treated and splenectomized, and chimeric mice prepared with TLI were inoculated in the hind foot pad with Mycobacterium marinum or Mycobacterium leprae. Although M. marinum organisms multiplied in greater numbers in the TLI mice, ultimately they were destroyed as effectively in TLI mice as in the non-irradiated control mice. M. leprae multiplied at the same rate and to the same maximum in TLI mice as in controls. Mice previously challenged with M. marinum in one hind foot pad, and challenged subsequently with the same organism in the opposite hind foot pad, showed a solid immunity against this reinfection. It appears that upon recovery from the immediate effects of radiotherapy TLI-treated mice are able to mount an effective immune response to experimental infection with M. marinum and M. leprae.

Specific health problems of Southeast Asian refugees in middle Tennessee.

Three diseases representative of specific health conditions affecting the Southeast Asian refugees living in middle Tennessee are leprosy (chronic bacterial infections), liver fluke infection (parasitic diseases), and hemoglobin E-beta-thalassemia (hematologic disorders). In this paper we discuss incidence, causative agent, mode of transmission, metabolic abnormalities, and management of these conditions.

Perturbation of lymphocyte circulation in experimental murine leprosy. II. Nature of the defect.

Intravenous infusion of radiolabeled thoracic duct lymphocytes (TDL)2 from normal syngeneic donors to rats experimentally infected with Mycobacterium lepraemurium fails to produce a significant increase of cell output and radioactivity within the thoracic duct lymph. Conversely, ther is a marked increase in cell counts and radioactivity in the thoracic duct lymph of control recipients. Splenectomy of infected rats prior to the infusion significantly increased the ouptut of cells and radioactivity from the TD of these rats although it was not restored to normal. Serial quantitation of radioactivity in lymphoid organs of infected rats after infusion of 51Cr-labeled TDL revealed significantly increased uptake by the spleen as compared with the spleens of controls. Thus, the spleen of infected rats was a major trap for recirculating TDL. TDL were also trapped to a lesser extent by the lymph nodes and liver of infected rats. The circulation of TDL was not disturbed significantly in control rats with massive splenomegaly and red pulp hyperactivity induced by i.p. injection of methyl cellulose. Since murine leprosy preferentially involves the periarteriolar lymphocyte sheaths of the splenic white pulp and paracortical area of lymph nodes, it is suggested that the disturbance of lymphocyte circulation is secondary to pathology within these areas.