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Biomedical subjects

H Takeyama

Publications and source records attributed to H Takeyama.

At least 163 records · Page 9Linked to original sources
PubMed1979

Induction of tumor resistance in mice by L1210 leukemia cells persistently infected with HVJ (Sendai virus).

A temperature-sensitive strain of Sendai virus, HVJ-pi, showed little or no cytopathic effect and led to establishment of carrier cultures in several cell lines. By the use of this characteristic, L1210 leukemia cells persistently infected with HVJ-pi (L1210/c--HVJ-pi) was established, almost all of which were positively stained with fluorescent HVJ antibody. They are viable and grow almost equally as uninfected L1210 leukemia cells in vitro. Athymic nude mice (BALB/c, nu/nu), deficient of T-cells, died from intraperitoneal inoculation of L1210/c--HVJ-pi cells as well as by uninfected L1210 leukemia cells. However, viable L1210/c--HVJ-pi cells showed lower transplantability in normal syngeneic mice. This immunological mechanism of rejection was explained by the modification of cell surface membrane due to HVJ-pi infection. The mice which survived the inoculation of 10(5) L1210/c--HVJ-pi cells were able to reject 10(5) uninfected L1210 leukemia cells challenged subsequently. The induction of immune resistance was more prominent in (C57BL/6 x DBA/2)F1 mice or (BALB/c x DBA/2)F1 mice than in DBA/2 mice.

Animals↗
PubMed1979

Properties of interferon induced by purified protein derivative of tuberculin in mice sensitized with BCG or cell-wall skeleton of BCG.

Mice sensitized with either BCG or cell-wall skeleton of BCG (BCG-CWS) produced interferon in blood after stimulation with specific antigen, purified protein derivative of tuberculin (PPD). Both BCG-infected normal (C57BL/6) and thymic nude (BALB/c, nu/nu) mice showed enhanced activity to produce interferon by stimulation with E. coli endotoxin. However, detectable interferon was not produced in athymic nude mice sensitized with BCG or BCG-CWS by stimulation with PPD. Immune-induced interferon (I-IF) produced by BCG-CWS and PPD in mice was different in biological and physicochemical properties from virus-induced interferon. I-IF showed about 100 times more potent L-cell growth inhibitory activity than virus-induced L-cell interferon (L-IF). Both I-IF and L-IF showed macrophage-activating activity, which renders resting macrphages cytotoxic to L1210 leukemia cells. Antiviral and macrophage-activating activity of interferon preparation was not separated physicochemically in this study.

Animals↗
PubMed1979

Common leukemia-associated antigen of DBA/2 mouse leukemia detected by tumor rejection and complement-dependent cytotoxicity assays.

A cytotoxic antibody for L1210 leukemia cells was found in the (C57BL/6 x DBA/2)F1 (BDF1) mice immunized with L1210 leukemia cells infected with ts mutant of HVJ (HVJ-pi) and challenged several times with uninfected L1210 leukemia cells. These immune mice fell into two categories; high and low responders regarding the titer of cytotoxic antibody produced. The antigen defined by this cytotoxic antibody was present on leukemia cells originating in DBA/2 mice but not on leukemia induced by passage-A Gross virus or spontaneous mammary tumors. This serological cross-reactivity among L1210, P388, and L5178Y leukemia cells has been substantially confirmed by the observation of cross protection against challenge with DBA/2 leukemia cells in immune BDF1 mice. These findings strongly suggested the presence of a common DBA/2 leukemia-associated antigen different from known cell-surface antigens of murine leukemia. The results obtained in the present work also demonstrated the great efficacy of non-cytopathic, viable HVJ-pi-injected tumor cells as an immunogen for inducing tumor immunity.

Animals↗
PubMed1978

Suppression of interferon production in mouse spleen cells by cytochalasin D.

Cytochalasin D is thought to impair microfilament function. The present study has investigated its effects on four different systems in which interferon is formed, namely (1) mouse fibroblasts induced with virus (2) mouse spleen cells induced with virus, or (3) with endotoxin or (4) by allogeneic stimulation. Cytochalasin D did not suppress formation of interferon by fibroblasts (L cells) or spleen cells stimulated with either HVJ or NDV. However it did suppress production of interferon by spleen cells in response to endotoxin or an allogeneic stimulation; here its action was apparently not on the secretion of interferon, but on some earlier event. It also suppressed the production of interferon by mouse spleen cells induced with HVJ if this had been u.v. irradiated for more than 15 min: this suggests that cytochalasin D sensitive structures do play some role in interferon production by mouse spleen cells when stimulated with HVJ, as well as when they are stimulated with endotoxin or an allogeneic stimulus.

Antigen-Antibody Reactions↗
PubMed1978

Acute lymphoblastic leukaemia of the B-cell type refractory to intensive chemotherapy.

Four patients, aged 15-50, with acute lymphoblastic leukaemia (ALL) shown to be of the B-cell type, since they formed rosettes with complement-coated sheep erythrocytes (EAC) and had lymphocytes bearing IgA on the cell surface. Clinically, they had massive leukaemic infiltration associated with hepatosplenomegaly and were extremely resistant to multiple, conventional chemotherapy, as demonstrated by prolonged therapy to achieve a remission or a short-term remission. The surface characteristics of the lymphoblasts in the circulating blood seemed to remain unchanged throughout the course of the leukaemia, despite intensive chemotherapy. The evaluation of surface markers on leukaemic cells might give better information for a forecast of the prognosis of the disease.

Adolescent↗
PubMed1978

A clinical trial of cell-wall skeleton of BCG in chemoimmunotherapy of acute leukemia.

A clinical trial of chemoimmunotherapy using cell-wall skeleton of BCG (BCG-CWS) was conducted in 28 patients with acute leukemia in complete remission. Chemotherapy consisted of monthly intensification therapy for 2 months and bimonthly therafter. Immunotherapy with 200 microgram of oil-attached BCG-CWS mixed with 10(7) autochthonous leukemic cells was given intradermally at either of upper or lower extremities every week, except when the patients were on maintenance therapy. No serious systemic side effect attributable to BCG-CWS was noted. Six patients developed mild and transient temparature elevation. Most importnat side effect was local skin reaction. Indulated papules developed in all patients, resulting in draining ulcerations in 26 patients. Increase of immunological reactivity of the patients receiving BCG-CWS was noted. Skin test response to PPD, Varidase, and candida extract showed definite increase. In vitro lymphocyte blastogenic response to PPD, concanavalin-A, and pokeweed mitogen revealed significant increase.

Adolescent↗