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Biomedical subjects

K Yoshimatsu

Publications and source records attributed to K Yoshimatsu.

122 records · Page 7Linked to original sources
PubMed1982

Luminous-efficiency functions for point sources.

Luminous-efficiency functions for small fields were measured with flicker photometry and heterochromatic brightness-matching methods for the same two subjects. For the larger stimuli (22.9 and 11.5'), the luminous-efficiency functions differed between the two methods. Those obtained by flicker photometry showed a simple narrow shape, whereas those obtained by heterochromatic brightness matching showed increased sensitivity at short and long wavelengths. The difference however, decreased as the stimulus was reduced to 2.3', and the luminous-efficiency functions converged to curves that resemble the CIE V (lambda ) or Judd's modification. It seems unnecessary to introduce a new luminous-efficiency function for point sources, which is fortunate for practical purposes.

Adult↗
PubMed1982

The modulation of murine immune responses by methyl-B12.

We examined the effect of methyl-B12 on the immune system. As a result, it was revealed that methyl-B12 enhanced antibody production in the in vitro system and that this activity was the strongest with methyl-B12 among the homologues of B12 examined, being nearly as strong as that of Levamisole. It was also revealed that methyl-B12 can exert an enhancing activity on the induction of suppressor T cells Con A. These facts suggest that methyl-B12 has a therapeutic effect against spontaneous incidence of diseases in NZA/W mice. These immunomodulative activities of methyl-B12 and their therapeutic significance against immune disorders were discussed.

Animals↗
PubMed1981

Isolation and characterization of a mitogenic substance for murine and human B lymphocytes from Ulex europeus seeds.

A mitogenic substance, which stimulates murine and human B lymphocytes, has been isolated from the seeds of Ulex europeus. The m.w. of this mitogen was estimated to be approximately 100,000 by sodium dodecyl sulfate disc gel electrophoresis. Under physiologic conditions Ulex mitogen was in the form of a polymer. The isolated mitogen was found to contain 80% carbohydrate, in which glucose, galactose, and rhamnose were the predominant sugars. The carbohydrate portion of the mitogen could be responsible for the mitogenic activity, since the activity was destroyed by periodate treatment but not by protease digestion. It is unlikely that the mitogenic activity is due to the contamination by lipopolysaccharide (LPS), because Ulex mitogen strongly activated spleen cells from C3H/HeJ mice and did not contain a detectable amount of fatty acid. Spleen cells from nude mice, T-depleted spleen cells from conventional mice, or T-depleted spleen cells from conventional mice, or T-depleted lymphocytes from human peripheral blood responded as strongly as lymphocytes (T + B) from normal origin as measured by 3H-thymidine incorporation. It seems that the mitogenic effect is primarily on B cells. Ulex mitogen also induced the increase of immunoglobulin synthesis in murine and human B cells.

Animals↗
PubMedDate not supplied

Effect of the synthetic lipid A-related compound, DT-5461, on resistance to Sendai virus infection in mice.

DT-5461 enhanced host resistance to Sendai virus infection in mice. Intranasal (i.n.) administration of 200 micrograms of DT-5461 per mouse 3 days before infection was the most effective administration route, dose and timing. DT-5461 enhanced the cytotoxicity of murine natural killer (NK) cells. In addition, DT-5461 activated murine peritoneal macrophages, resulted in augmented of cytotoxicity and the induction of tumor necrosis factor-alpha (TNF-alpha). Therefore, these immunomodulating activities presented by DT-5461 caused protection against Sendai virus infection.

Adjuvants, Immunologic↗
PubMedDate not supplied

Adjuvant activity of muramyl dipeptide derivatives to enhance immunogenicity of a hantavirus-inactivated vaccine.

The adjuvant effect of two lipophilic derivatives of muramyl dipeptide (MDP), B30-MDP and MDP-Lys(L18), on the ability of an inactivated vaccine of B-1 virus (B-1 vaccine) to induce immune response against Hantavirus causing hemorrhagic fever with renal syndrome (HFRS) was examined. When mice were immunized subcutaneously (s.c.) twice at 2-week intervals with B-1 vaccine admixed with or without 100 micrograms mouse-1 of B30-MDP (B-1/B30-MDP) or MDP-Lys(L18) [B-1/MDP-Lys(L18)], mice immunized with B-1/B30-MDP as well as B-1/MDP-Lys(L18) showed significantly higher indirect fluorescent antibody (IFA) titers against HFRS virus than mice immunized with B-1 vaccine alone. Both mice treated with B-1/B30-MDP and B-1/MDP-Lys(L18) also exhibited significantly higher neutralizing antibody titers against HFRS virus than mice immunized with B-1 vaccine alone during 3-9 weeks after the primary immunization. The evaluation of antibody-producing cells by enzyme-linked immunospot (ELISPOT) assay on week 4 revealed that both MDP derivatives enhanced the number of HFRS virus-specific IgG1 and IgM antibody-producing cells. Furthermore, mice treated with B-1/B30-MDP as well as B-1/MDP-Lys(L18) showed a higher level of Th-2 type cytokines, IL-4 and IL-6, in sera than mice treated with B-1 alone. In an in-vitro analysis of T lymphocyte proliferation to baculovirus-expressed recombinant nucleocapsid protein (rNP) of Hantaan 76-118 strain, the splenocytes of mice treated with B-1/B30-MDP and B-1/MDP-Lys(L18) on week 4 showed a significantly higher proliferating activity than those treated with B-1 vaccine alone. In addition, when mice were immunized once with B-1 vaccine admixed with or without B30-MDP and MDP-Lys(L18) and followed by intrafootpad (i.f.) injection of B-1 vaccine on day 7, mice immunized with B-1/B30-MDP and B-1/MDP-Lys(L18) induced a higher delayed-type hypersensitivity (DTH) reaction than mice immunized with B-1 vaccine alone. These results suggest that B30-MDP and MDP-Lys(L18) are useful immunoadjuvants to enhance the ability of inactivated B-1 vaccine to induce a humoral and cellular response to HFRS virus.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMedDate not supplied

Determination of cardenolides in hairy root cultures of Digitalis lanata by enzyme-linked immunosorbent assay.

A competitive ELISA technique using digoxin-specific antibody has been developed to determine digoxin and its related compounds in hairy root cultures of Digitalis lanata. The ELISA could detect 0.2-2 nM digoxin and closely related cardenolides. Hairy roots cultured in the dark accumulated very small amounts of cardenolides (0.02-0.07 micrograms/g dry wt), while the content of cardenolides in green hairy roots cultured in the light was increased maximally 600-fold (16.5 micrograms/g dry wt) compared to those in the dark.

Antibodies, Monoclonal↗
PubMedDate not supplied

Intrahepatic lymphocyte analyses and assessment of the effects of levamisole in murine hepatic metastasis model.

We used hepatic metastasis models to determine the mechanism and effect of levamisole. BALB/c mice and Colon 26 cells were used. Group I was injected with tumor cells through the portal vein. Group II was primed with tumor cells before tumor cells injecting. Group III was same as Group II, but treated with levamisole. Surface antigens of intrahepatic lymphocytes and spleen cells were determined by FACScan with Anti-CD3, anti-CD4, anti-CD8, anti-CD45, anti-NK1.1 and anti-F4/80. Nodules on the liver were greatest in Group I and fewest in Group III. Concerning intrahepatic lymphocytes, Group II, when compared with Group I, had increases of CD3+, CD4+ and CD8+ cells, and decreases of CD45+ and NK1.1+ cells. Group III when compared with Group II, showed increased CD8+ cells and decreased of NK1.1+ cells. Levamisole is considered to be effective in the prevention of liver metastasis and is suggeste to enhanced CD8+ cells.

Adjuvants, Immunologic↗