Acta Medica Okayama volume24 issue6

Transformation of Japanese encephalitis antibody from IgM to IgG in the sera of the experimental infected chicks with Japanese encephalitis virus and transmission of IgM or IgG from hen to chicks were examined by the gel filtration on Sephadex G-200 column. The following results were obtained. 1. Titer of hemoagglutination inhibiting antibody rose on seven days after inoculation of mouse brain homogenate infected with Japanese encephalitis, and that increased rapidly after the second inoculation of Japanese encephalitis. The maximum peak of antibody titer attained on 35 days after the first inoculation, on 7 days after the second inoculation and it maintained for a period of 2 months then decreased. Viremia was detected till 6 hours after the first inoculation. 2. IgM antibody by gel filtration appeared on 7 days after the first inoculation, kept on rising, reached the peak on 35 days after the first inoculation, then decreased, and disappeared on 120 days. IgG antibody appeared about 2 weeks after the IgM antibody appearance, and the titer of IgG antibody became higher than that of IgM antibody on 35 days after the first inoculation, then decreased gradually, and showed 1 : 16 of titer of peak on 150 days by gel filtration. 3. We could obtain the chicks by fertilization from experimentally infected hen, having IgM and IgG of hemoagglutination inhibiting antibody of Japanese encephalitis. And the localization of antibodies in the sera of its chicks was determined by Sephadex G-200 gel filtration. And IgG antibody was detected in chick serum, though IgM antibody was not detected by this method.

1. Mitochondria isolated from hamster tumors induced by adenovirus type 12 possessed circular DNA fibers. 2. The mean value of the length of the highest frequency group of the circular DNA molecules was 4.92 ±0.38 μ. 3. Catenated dimer DNA molecules and small (less than 2 μ in length) circular DNA molecules were observed.

As to trial toward the elimination of Japanese encephalitis virus in natural surroundings, pigs received inoculation of inactivated Japanese encephalitis vaccine supplemented with complete Freund's adjuvant twice at one-week interval. Effect of adjuvant supplement on the magnitude of antibody and also prevention of viremia caused by natural infection by antibody induced with vaccine were investigated. The results of this study are summarized as follows. 1. In the group of pigs inoculated with vaccine containing adjuvant, titer of hemoagglutination inhibiting and neutralizing antibodies was higher than those inoculated with vaccine alone and their high titer persisted. 2. With respect to natural infection of pigs, on August 22 when the pigs were thought to have been infected, there was observed a rise in antibody titers. And on antibody formed in those pigs inoculated with vaccine with or without adjuvant proved to be all 2-ME resistant type, whereas the antibodies produced in control group were 2-ME sensitive antibody. 3. Viremia was detected in the blood of pigs naturally infected, but it was not demonstrated pigs inoculated with vaccine supplemented with adjuvant or without adjuvant. The virus of pig blood which was inoculated into suckling mouse brain and was separated after low suckling passage mouse was supposed to be JaGAr strain from optimum hydrogen ion concentration of its hemoagglutination reaction. 4. Effect of vaccination on antibody response of pigs having maternal antibody was not recognized.

The first successful electron-microscopic observation of a virus isolated from a patient with SMON was performed. The morphological and developmental characteristics of this virus suggests that this type of virus has not been isolated from humans. Hence, it is considered that the virus observed is of a new type and presumably the causative agent of SMON. The author wishes to express his profound thanks to Prof. TADASHI OFUJI for painstaking proof reading of the manuscript and also acknowledgement is due to Mr. NOBUO HAYASHI, Mr. NOBORU SAIHARA, Mr. TAKASHI NAKAMURA and Miss TOSHIYO OMIZU for their technical assistance of electron microscopy.

Morphological comparison at colonial level was made on a series of established liver cell lines derived from rats fed 4-dimethylaminoazo-benzene (DAB) for various periods of days for the purpose of elucidating more accurately the differences in morphology and growth patterns among these cell lines. Colonies of each cell line produced by the single cell plating technique were compared with regard to colony size, density and piling-up of cells, atypism and pleomorphism of cells, and the migration of cells from colonies. Plating efficiency of each cell line was also compared. The cultured rat liver cells obtained from those rats fed DAB for a longer period of days showed higher plating efficiency, and increased the incidence of large-sized, dense, and piled-up colonies, of colonies consisted of cells having nuclear atypism and pleomorphism, and of irregularly margined colonies with migrating cells. The correlation between the present results and the process of DABcarcinogenesis is discussed.

We applied unidirectional MLC test to skin allografts in dogs, and examined the correlation between the strength of the MLC reaction and the survival time of skin allografts. As a result it was found that the skin allografts was rejected within 10 days when the rate of blastformation was more than 18 %. In contrast, the skin graft survived over 13 days when the rate was less than 15 %. The rate of blastformation was inversely correlated with the median survival time of skin allograft.