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Biomedical subjects

K Takamura

Publications and source records attributed to K Takamura.

At least 55 records · Page 3Linked to original sources

[Intraocular fluid antibody quotients following inoculation with two different antigens in experimental herpes simplex virus retinochoroiditis].

Viral retinochoroiditis was induced experimentally by inoculation of herpes simplex virus into the vitreous body in rabbits. The animals were sensitized systemically using 2 pathogens as antigens (herpes simplex virus and toxoplasma gondii) 3 weeks prior to intraocular inoculation. Serum and intraocular fluid were collected 2 weeks after inoculation. The intraocular fluid antibody titers and quotients for these 2 pathogens were then measured to determine the effects of serum antibodies, which are thought to enter the eyes as a result of destruction of the blood-ocular barrier. Experimental criteria for antibody quotients were also determined. Antibody quotients for the etiological virus (herpes simplex virus) ranged from 2 to 20, with an average of 9.7. Those for toxoplasma gondii, the antibody of which is thought to enter the eye from the blood, were all less than 5 with average of 1.9. From these results, it would seem that when the antibody quotient of a pathogen in more than 6 in the intraocular fluid, it is likely to be an etiological organism, while the possibility of infection is very low when the quotient is under 2. More precise studies are required to identify an etiological pathogen when the quotient is 2-6.

Animals↗

Changes in body proportions of Japanese medical students between 1961 and 1986.

Since 1945, the Japanese physique has changed a great deal. Physical examinations of medical students at Kyushu University have been carried out on an annual basis since 1939. We investigated changes in body proportions using data on 813 medical students examined from 1961 to 1986. During these 26 years, standing height has increased by 4.69 cm, arm length by 2.58 cm, and sitting height by 0.79 cm. Thus, the Japanese have grown taller and their extremities are longer, yet the trunk has not changed significantly. This study also shows a 10-year delay in increase in length of the upper extremities.

Adult↗

Expression of epidermis-specific antigens during embryogenesis of the ascidian, Halocynthia roretzi.

We have produced two monoclonal antibodies (Epi-1 and Epi-2) which specifically recognize epidermal cells and their derivative, the larval tunic, of developing embryos of the ascidian Halocynthia roretzi. The antigens, examined by indirect immunofluorescence staining, first appear at the early tailbud stage and are present until at least the swimming larval stage. There were distinct and separate puromycin and actinomycin D sensitivity periods for each antigen. Aphidicolin, a specific inhibitor of DNA synthesis, prevented the appearance of each antigen when embryos were exposed to the drug continuously from cleavage stages. These results suggest that the antigens are synthesized during embryogenesis by developing epidermal cells and that several rounds of DNA replication are required for the antigen expression. Early cleavage stage embryos, including fertilized but unsegmented eggs, in which cytokinesis had been blocked with cytochalasin B expressed the antigens, and blastomeres exhibiting the antigens were always of the epidermis lineage. In partial embryos produced by four separated blastomere pairs of the 8-cell embryos, the expression of antigens was seen only in those developed from the animal blastomere pairs, which are progenitors of epidermal cells. These observations indicate that differentiation of epidermal cells in ascidian embryos takes place in a typical "mosaic" fashion.

Animals↗

Effect of phospholipase A2 on Ca2+-stimulated adenosine triphosphatase activity in microsomal fraction of rat submandibular gland.

The effect of phospholipase A2 on the Ca2+-ATPase (EC 3.6.1.3) activity in the microsomal fraction of rat submandibular gland was kinetically studied in vitro. The Ca2+-ATPase activity was significantly increased by the treatment with phospholipase A2 in the presence of bovine serum albumin as a scavenger for hydrolyzed products. When the microsomal fraction was incubated with phospholipase A2 in the absence of bovine serum albumin, the Ca2+-ATPase activity was not altered. The Vmax and Km values for both ATP and Ca2+ were increased by the phospholipase A2 treatment, respectively. These results indicated that the activation of Ca2+-ATPase by the phospholipase A2 treatment is due to the increase of Vmax.

Animals↗