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Biomedical subjects

T Masuda

Publications and source records attributed to T Masuda.

At least 757 records · Page 42Linked to original sources
PubMed1981

Immunological properties of Fc receptor on lymphocytes. 9. Functional analysis of FcR gamma+ and FcR gamma- lymphocytes in IgE antibody responses.

The present study was undertaken to clarify the function of FcR gamma+ and FcR gamma- lymphocytes in anti-DNP IgE antibody responses. The helper activity was observed predominantly in FcR gamma- T cells, but poorly in FcR gamma+ T cells, as in the case of IgG antibody responses, indicating that the absence of FcR gamma on T cell surface is a common surface characteristic to helper T cells, and that there is no close relationship between the determination of class specificity of Ig and T cell subsets divided by the presence or absence of FcR gamma. Furthermore, IgE antibody responses were more dependent upon helper T cells than IgG antibody responses. The data presented in this paper also demonstrated that the precursors of anti-DNP IgE antibody-forming cells were equally contained in both FcR gamma+ and FcR gamma- B cells, when they were transferred into recipients with helper T cells. This is a striking contrast to IgM/IgG antibody responses, in which only FcR gamma- B cells could differentiate into antibody-forming cells. Moreover, the precursor activity of FcR gamma+ and FcR gamma- B cells for IgE antibody-forming cells was not affected by the treatment of cells with suppressive B cell factor released from FcR gamma+ B cells after binding of antigen-antibody (IgG) complexes and known to suppress the proliferation of FcR gamma- IgM/IgG antibody-forming cell precursors. Thus, IgE B cells seem to be more heterogeneous than IgM/IgG B cells with respect to the FcR gamma marker and insensitive to the regulatory effect of FcR gamma+ B cells. IgE B cells are regulated differently from IgG B cells in B-B cell interactions.

Animals↗
PubMed1981

Scanning electron microscopy of corrosion cast of rat adrenal vasculatures with emphasis on medullary artery under ACTH administration.

In the vascular system of the adrenal, the medullary artery is considered to be a shunt which controls cortical function by changing its diameter. To confirm this hypothesis, the medullary arteries of ACTH-treated and control rats were observed by scanning electron microscopy of methacrylate corrosion casts of blood vessels. After ACTH treatment, the medullary arteries were constricted mostly at their distal segments and sometimes also at other portions. This constriction probably results in an effective augmentation of adrenocortical blood flow. The diameter of capillaries in the glomerular zone and medullary sinusoids was markedly increased by ACTH. Small protrusions o the corrosion casts which supposedly corresponded to capillary fenestrations became prominent after ACTH administration in the fascicular and reticular zones.

Adrenal Glands↗
PubMed1981

Enhancement of immune responses and possible inhibition of suppressor cells by aclacinomycin A.

Antitumor antibiotics were examined as possible candidates that possess activity which inhibits preferentially suppressor cells in comparison with effector cells. In screening for such compounds among known antibiotics, aclacinomycin was found to augment antibody formation and delayed-type hypersensitivity in mice over a wide concentration range. The addition of aclacinomycin to mouse spleen cell cultures also enhanced antibody formation in vitro. The generation of suppressor cells or the suppressor activity per se in mice immunized with high doses of SRBC was reduced by aclacinomycin. These results suggest that the drug may possibly inhibit suppressor cells selectively. The administration of aclacinomycin at ow doses exhibited antitumor effects on IMC carcinoma; the effect was not dose-dependent.

Aclarubicin↗
PubMed1981

[Erythema rheumaticum].

A case of typical erythema rheumaticum is presented with emphasis on clinical, histological, immunopathological and immunological findings. Pathogenesis and therapy are shortly discussed.

Acute Disease↗
PubMed1981

Dimer formation in radiation-irradiated aqueous solution of lysozyme studied by light-scattering-intensity measurement.

The reaction of lysozyme with OH., Br.-2 and e-aq, produced in an aqueous solution by pulsed electrons and gamma-rays, were investigated. Irradiated enzymes showed an increase in the light scattering intensity (LSI) which is proportional to the absorbed dose. Results obtained from SDS gel electrophoresis confirm dimerization of lysozyme, which is considered to be responsible for the increase in LSI. It was found that the rate constant of the dimerization of protein radicals produced in the reaction with OH. is 2K=(1.0 +/- 0.3) X 10(6)M-1 s-1 and the yield of the dimerization is 0.6 in G. The enzymatic activity of the dimer is shown to be reduced to about 30 per cent of that of the intact enzyme. It is concluded that the radiation-induced inactivation of lysozyme is largely due to dimerization.

Electrons↗
PubMed1981

[Use of cefroxadine dry syrup in the management of acute skin infections in children (author's transl)].

1. Cefroxadine dry syrup was in principle administered at the dosage of 10 mg per kilogram of body weight 3 times a day. 2. Evaluation was done in 4 grades, i.e. excellent, good, fair and poor. 3. According to subjective judgement by attending doctors, 'excellent' or 'good' was recorded in 90.7%. 4. If the evaluation was partially standardized, 'excellent' or 'good' was obtained in 74.8% of total 163 cases and in 78.7% of 108 impetigo cases. 5. Side effects were observed in 3 cases (diarrhea 1, fever 2). No direct correlation of these complaints with the administration of the present drug was confirmed.

Abscess↗
PubMed1981

Membrane expression of Fc-receptors in cultured leukemic cell lines. I. Induction of Fc-receptor in undifferentiated types of cells after passive modulation of lipid viscosity.

The role of lipid environment of plasma membrane for the expression of Fc receptor (gamma) (FcR gamma) were studied by physicochemical modification of the membranes of myeloid leukemia cell line cells, M1. Sterol binding polyene antibiotics such as amphotericine B or filipin inhibit the expression of FcR gamma during the differentiation of M1- cells by the CM obtained from the culture of mouse embryonic fibroblasts, suggesting the possible involvement of cholesterol molecules in the induction mechanism of FcR gamma. Low-temperature incubation at either 20 degrees C or 4 degrees C results in the increment of their membrane microviscosity, when tested by the fluorescence depolarization method, in company with the appearance of FcR gamma on approximately 60% of M1 cells when assayed by the EA-rosetting method. FcR gamma is also induced on approximately 40% of M1- cells by incubating cells with cholesterol-phosphatidyl-choline liposomes with the concomitant increase of their membrane microviscosity. Nevertheless, no phagocytosis of EA is observed in these cells treated with such physicochemical procedures. These findings imply that FcR gamma is embedded in the membrane of M1- cells and that physicochemical modification of the membrane lipid bilayers can induce the FcR gamma independent on their functional differentiation marked by the expression of phagocytic activity.

Animals↗
PubMed1980

Transient immune deposits in the papillary dermis and in the epidermis. A light-microscopical study on the experimental Arthus reaction.

To have as further insight into the localizations of immune deposits in the skin the reversed passive and the passive Arthus reactions were carried out in the foot-pads skin of guinea-pigs using horseradish peroxidase as antigen. The transient localizations of immune deposits in the papillary dermis and in the epidermal cell layer were observed in the skin of the reversed passive Arthus reaction, but not in the skin of the passive Arthus reaction. Following the immune deposits in the papillae including the capillary walls and the dermoepidermal junction, the papillary dermis became widened, swollen, and edematous, being infiltrated by PMN's. In the epidermal layer, the immune deposits were found as fine granular aggregates adhering to the epidermal cells or to the dendritic cells. Although the immune deposits disappeared promptly from the papillae and the inflammatory reactions were slightly and transient, the epidermal cell layer became thickened, and several mitotic figures of the epidermal cells were observed.

Animals↗