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Biomedical subjects

M Homma

Publications and source records attributed to M Homma.

At least 307 records · Page 17Linked to original sources
PubMed1982

Absence of Carp's agent in sera of patients with multiple sclerosis in Japan.

A study was devised to test for Carp's agent in the sera of Japanese patients with multiple sclerosis (MS). The sera were obtained from 17 patients with definite MS and six patients with possible MS. Strain C3H mice were given an intraperitoneal injection of 0.1 mL of each serum. One week before and 1, 3, and 6 weeks after inoculation, blood drops from tail tip were smeared and polymorphonuclear leukocytes (PMNLs) were counted. Although the experimental animals were kept under careful control, substantial fluctuation in the number of PMNLs occurred, and the variations of PMNL count in the experimental groups were all within the normal range. We conclude that there is no Carp's agent in the sera of patients with MS in Japan.

Animals↗
PubMed1982

In vitro immune response of SLE lymphocytes. The mechanism involved in B-cell activation.

Peripheral blood lymphocytes from 26 patients with systemic lupus erythematosus (SLE) and six normal individuals were tested for IgG synthesis in the presence or absence of PWM. Lymphocytes from patients with active SLE synthesized increased amounts of IgG in the absence of PWM and reduced amounts of IgG in the presence of PWM. Serum from patients with active SLE had an enhancing effect on the in vitro IgG synthesis of normal lymphocytes. The IgG or F(ab')2 fractions of SLE serum retained the enhancing effect on in vitro IgG synthesis, and the enhancing activity was absorbed by human spleen cells. As little as 4 h of incubation with SLE serum was needed for the enhancing activity of normal lymphocytes. Treatment of B lymphocytes appeared to be of main importance for an increase in the in vitro IgG synthesis of SLE serum-treated lymphocytes. These results suggest that anti-B-lymphocyte antibodies from patients with active SLE are responsible in part for the hyperactive response of SLE B lymphocytes.

Antibody-Producing Cells↗
PubMed1982

Correlation between clinical activity of systemic lupus erythematosus and the amounts of DNA in DNA/anti-DNA antibody immune complexes.

The relationship between clinical activity of systemic lupus erythematosus (SLE) and molecular sizes of DNA fragments isolated from DNA/anti-DNA antibody immune complexes were examined. Among sera from twenty-eight patients with SLE examined, three different molecular sizes of DNA were identified, namely, DNA of m.v. 25,000 with 30 to 50 base pairs (bp); m.w. 100,000 with 150 to 200 bp; and m.w. 200,000 with 300 bp. On the basis of the molecular sizes of DNA fragments, we can divide patients with SLE into four groups. The first group contained DNA predominantly of m.w. 25,000. The second group contained DNA predominantly of m.w. 100,000. The third group contained DNA of m.w. 200,000. The fourth group contained both m.w. 25,000 and 100,000. A method to quantitate the amounts of DNA in DNA/anti-DNA immune complexes was developed. The amount of DNA fragments was estimated by measuring the amount of 32P-phosphate incorporated into 5 ends of DNA. Patients with severe disease tended to have greater amounts of DNA (up to 400 ng/ml serum). Two serial studies also support this result. Thus, the quantitative analysis shows that the amount of DNA in the immune complexes is highly correlated with disease activity (r = 0.864; p less than 0.001). These results suggest that DNA/anti-DNA immune complexes may play some role in the pathogenesis of lupus nephritis.

Adolescent↗
PubMed1981

Protein synthesis in Vero cells abortively infected with influenza B virus.

Growth of influenza B virus was found to be greatly restricted in Vero cells compared with that in MDCK cells. The analysis of protein synthesis in infected cells showed that the synthesis of M protein is selectively inhibited in abortive infection. Cell fractionation experiments demonstrated that the viral glycoproteins, HA and NA, migrate from rough membranes via smooth membranes to plasma membranes in abortive as well as in productive cells. These results suggest that intracellular migration of influenza B virus glycoproteins occurs independently of the synthesis of M protein although M protein synthesis appears to be required for the formation of virus particles.

Animals↗
PubMed1981

A comparison of proteins among various influenza B virus strains by one-dimensional peptide mapping.

The major virus-specific proteins (HA, NA, NP, NS1 and M) of five different isolates of influenza B virus (B/Lee/40, B/Osaka/2/70, B/Yamagata/1/73, B/Aomori/1/76 and B/Yamagata/26/77) were compared by limited proteolysis with Staphylococcus aureus V8 protease and subsequent polyacrylamide gel electrophoresis. The peptide patterns of matrix (M) proteins from all five strains were virtually identical. The nucleoproteins (NP) as well as the non-structural proteins (NS1) were also very similar among strains although the peptides of B/Lee/40 could be distinguished from those of the strains isolated from 1970 to 1977. In contrast, the peptides from haemagglutinin (HA) glycoproteins were largely different even among the strains isolated later than 1970. It therefore appears that the HA glycoproteins of influenza B virus are more changeable than any of the non-glycosylated proteins. Furthermore, it was found that the maps of HA1 were markedly different among strains while the maps of HA2 were very similar, which suggests that the structural changes in the HA polypeptide occur preferentially in the HA1 portion. The neuraminidase (NA) glycoproteins also showed strain-dependent differences in their mapping patterns.

Electrophoresis, Polyacrylamide Gel↗
PubMed1981

Mode of subacute sclerosing panencephalitis (SSPE) virus infection in tissue culture cells. III. Neurovirulence of cell-free SSPE viruses of Niigata-1, Kitaken-1, and Biken strains.

Cell-free viruses recovered from virus-carrying cultures of the Niigata-1, Kitaken-1, and Biken strains of SSPE virus were examined for neurovirulence. The cell-free viruses were prepared by freezing and thawing or by EDTA treatment of the virus-carrying cultures and inoculated into adult mice intracerebrally. A considerable number of the inoculated mice showed clinical signs about 1 to 5 weeks after the inoculation. The first symptom was hyperreactivity, which was followed by paresis and myoclonus. All of the affected mice fell in paralysis and finally died. The virus could be recovered from the moribund mice by cocultivation of the brain cells with Vero cells. Immunofluorescence staining of the brain tissue revealed that infected cells containing viral antigens were distributed sparsely. No inflammatory feature, however, was observed in the brain as far as examined and neutralizing antibody against SSPE virus was not detected in sera from the mice inoculated with the cell-free SSPE viruses.

Animals↗
PubMed1981

Evidence of aberration of T-cell subsets in aged individuals.

In the present study, T-cell subsets from aged individuals were examined by using anti-BAT (brain-associated thymocyte antigen) serum. Anti-BAT serum was raised against the human fetal brain at 28 weeks of gestation. After absorption wit AB erythrocytes, B-cell lines, and leukaemic cells, anti-BAT serum was T cell-specific but unreactive to normal B cells. The ability of anit-BAT serum-treated lymphocytes from aged individuals to respond to concanavalin A, phytohaemagglutinin, and pokeweed mitogen (PWM) was unaltered even at a high concentration. In PWM-stimulated Ig synthesis, T lymphocytes lacking the anti-BAT serum-reactive T-cell subset enhanced the PWM-stimulated Ig synthesis of autologous B lymphocytes from young individuals. The Con A-induced suppressor function of lymphocytes from aged individuals was not significantly abolished by treatment with anti-BAT serum and complement. In the autologous mixed lymphocyte reaction, the decrease in response was minimal when responder cells from aged individuals was treated with anti-BAT serum even at a high concentration. It is concluded that the T-cell subset with suppressor function is defective in aged individuals.

Adult↗
PubMed1981

Mitogenic responses to lipopolysaccharide by B lymphocytes from patients with systemic lupus erythematosus.

Peripheral blood lymphocytes from 43 patients with systemic lupus erythematosus (SLE) and from age- and sex-matched normal controls were cultured with lipopolysaccharide (LPS) to examine the response to the polyclonal B-cell activator. Lymphocytes from active SLE patients incorporated 4840 +/- 471 (mean +/- SE) cpm in response to LPS, whereas lymphocytes from inactive SLE patients incorporated 6906 +/- 897 cpm. In contrast, lymphocytes from normal individuals incorporated 7452 +/- 1126 cpm. Ig synthesis of lymphocytes from active SLE in response to LPS stimulation was also less than that of normal individuals. The helper T-cell function of active SLE, as examined by co-culturing irradiated SLE lymphocytes with unirradiated normal lymphocytes, was normal. These results thus suggested that a defect of B lymphocytes exists in active SLE patients. This B-cell defect and T suppressor cells apparently play an important role in the pathogenesis of SLE.

Adult↗