Masahiro Chiga

Successful treatment of a malignant rat glioma with cytotoxic T lymphocytes.

Brain tumors are highly resistant to therapy. Their diffuse infiltrative nature and the relative inaccessibility of brain tissue to blood and lymph are barriers to surgical and cytotoxic treatments alike. The purpose of this study was to produce immune cells specifically reactive with an anaplastic rat glioma (RT2) and determine whether those cells could affect tumor progression in the brain. RT2-specific cytotoxic cells were prepared by priming rats in vivo with RT2 tumor cells and Corynebacterium parvum and stimulating the primed lymphocytes in vitro with irradiated RT2 tumor cells and interleukin-2 (IL-2). Cultured cells exhibited a high level of cytotoxicity against RT2, but not C6 (an allogeneic glioma), 3M2N (a syngeneic mammary tumor), or CSE (a syngeneic fibrosarcoma) tumor cells. To generate a model for therapy, rats were injected intracerebrally with RT2, generating progressing brain tumors, which killed untreated rats in approximately 2 weeks. To test the therapeutic potential of the effector cells, tumor-bearing rats were treated by intravenous injection of lymphocytes on Day 5 of tumor growth. Treated rats also received a 5-day course of systemic IL-2 beginning on Day 5. Treatment with IL-2 alone, RT2-primed spleen cells, or RT2-primed spleen cells stimulated in vitro with C6 did not affect rat survival. However, tumor-bearing rats treated with RT2-stimulated lymphocytes exhibited increased survival or were cured. Systemic IL-2 was an essential adjunct, because survival was not affected by treatment with effector cells alone. Therapy initiated on Day 8 of tumor progression lacked effect on survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Stimulation of liver catalase synthesis in rats by ethyl-α-p-chlorophenoxyisobutyrate

Abstract In male rats fed 0.25% CPIB in diet 1 to 2 weeks, the concentration of catalase protein in liver extract was 2.1 times that of controls. With immunochemical methods, it was shown that CPIB enhances the rate of synthesis of hepatic catalase by more than 80% in three days and maintains this enhanced synthesis throughout the duration of its administration.

Disseminated histoplasmosis in acquired immunodeficiency syndrome: Light and electron microscopic observations

Two young homosexual men with acquired immunodeficiency syndrome (AIDS) presented with five-lobe pneumonia and maculopapular rash, respectively, and were found to have disseminated histoplasmosis by examination of peripheral blood smears. Bone marrow smears from one patient revealed more numerous Histoplasma capsulatum organisms than peripheral blood smears did. Electron microscopy of peripheral-blood buffy coat demonstrated histoplasma organisms in monocytes and neutrophils as well as tubuloreticular structures in small lymphocytes. A search for Histoplasma capsulatum in peripheral blood smears from patients with AIDS is warranted, especially in endemic midwestern states.

Identification of herpes simplex virus infection by immunoperoxidase and in situ hybridization methods

Seven cases of visceral herpes simplex virus (HSV) infection were observed in five cases of hematopoietic disease and in one case each of a newborn baby and a pregnant woman. These seven cases were studied with an immunoperoxidase method and in situ hybridization. In HSV lesions of squamous epithelium, the immunoperoxidase method using rabbit anti-human HSV revealed positive staining, mainly in the nucleus but with some cytoplasmic staining. DNA in situ hybridization revealed stronger positive staining in the nucleus. In HSV hepatitis positive staining was seen in the nucleus and cytoplasm, both by immunoperoxidase and in situ hybridization methods. In the newborn baby, HSV lesions were observed in the brain only, with numerous positive astrocytes identified by the immunoperoxidase method and a few positive astrocyte nuclei by in situ hybridization. Cultured human fetal fibroblasts from the lung were infected with HSV. The immunoperoxidase method revealed diffuse positive staining in the nucleus and in the cytoplasm whereas in situ hybridization revealed fibrillar positive staining in the nucleus only. Thus, the immunoperoxidase method using rabbit antihuman HSV can detect the presence of HSV protein more sensitively than in situ hybridization, probably because of the greater quantity of HSV protein compared with HSV DNA in infected cells.

The Role of Membrane Phospholipid in Expression of Erythrocyte Rh0(D) Antigen Activity

Abstract Previous investigators have reported that the expression of Rho(D) antigen activity by human erythrocytes and their membranes depended on the presence of phospholipid. In order to further elucidate the role of phospholipids in expression of Rho(D) antigen activity, erythrocyte membranes and partially purified Rho(D) antigens were incubated with bee venom phospholipase A2. Treatment of erythrocyte membranes with phospholipase A2 resulted in loss of Rho(D) antigen activity as detected by hemagglutination inhibition assays. However, subsequent solubilization of these treated membranes with deoxycholate allowed recovery of Rho(D) antigen activity. Phospholipase treatment of solubilized Rho(D) antigens, which had been partially purified by affinity chromatography on anti-Rho(D) IgG agarose columns, did not destroy Rho(D) antigen activity. These results suggested that phospholipids did not affect the antigenic determinants of the Rho(D) antigen since solubilized, partially purified Rho(D) antigens retained their antigenicity following exposure to phospholipase. Phospholipids were presumably required for proper orientation of Rho(D) antigens within erythrocyte membranes since Rho(D) membranes lost their antigenicity following phospholipase treatment.

Identification of cytomegalovirus infection in acquired immunodeficiency syndrome

Cytomegalovirus (CMV) infection was observed in 10 of 12 autopsy cases of acquired immunodeficiency syndrome (AIDS) and appears to be the commonest life-threatening viral infection in AIDS. In all 10 cases, adrenal glands were affected with CMV and adrenal medullary necrosis was present in 6 cases. Lungs were affected with CMV in 7 cases with disseminated infection and positive CMV culture. In situ hybridization of tissue sections with CMV-specific DNA provided positive staining for CMV in inclusions as well as other infected cells without obvious inclusions. Human diploid lung fibroblasts were infected with isolated CMV in culture, yielding positive CMV identification within 5 days by in situ hybridization before specific cytopathic changes appeared in the fibroblasts. The early and specific detection of CMV is possible by in situ hybridization with cultured fibroblasts.