Naoki Nakazono

Evolution of enterovirus type 70: Oligonucleotide mapping analysis of RNA genome

Different isolates of enterovirus type 70 (EV70) taken between 1971 and 1981 were studied by molecular biological methods to elucidate their evolutional change. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that only a few isolates had a slight alteration in mobility in some viral proteins. On the contrary, oligonucleotide mapping of virion RNA could clearly delineate the molecular changes among isolates. The number of base changes of isolates became greater as the years elapsed. In addition, the number of base changes among recent isolates from different areas of the world was much greater than those among early isolates. Thus, when the isolates were arranged three-dimensionally according to the number of base changes between each other, the constellation of the strains gave rise to a conical shape. The central axis of the figure was the time of isolation of the strains. The early isolates clustered near the top of the conical figure and the recent isolates tended to disperse divergently at the bottom. The figure indicated that all EV70 strains were derived from a common ancestor, and its top would be the time of emergence of the original strain. It was estimated to be around 1966, 3 years prior to the first epidemic in Accra, Ghana. From the results, it was presumed that EV70 would have emerged at a single focus in Africa as a novel human virus. After having circulated there for a few years, the virus spread to the other parts of the world. Based on the difference in the oligonucleotide spots between the recent isolates and early isolates, the base changes of EV70 that occurred during 10 years was estimated to be 320, about 4% (0.4% a year on the average) of the bases of the total RNA genome.

Factors associated with clinical reactions to rubella vaccination in women

Two types of rubella vaccine were given to 272 seronegative healthy Japanese adult women. Clinical and laboratory studies on clinical reaction after vaccination were carried out on HI antibody response, HLA types, basal body temperature (BBT), menstrual cycles and serum progesterone levels of vaccinees. Clinical reactions were not associated with HLA types of vaccinees, but arthropathy occured significantly more often in women vaccinated at the progestational stage than in women vaccinated at the estrogenic stage.

Clinical and Etiological Study of Viral Conjunctivitis During six Years, 1974–1979, in Sapporo, Japan

Among 357 viral conjunctivitis tested during 6-year study, 219 (61%) were virologically and/or serologically detected; consisting of 76 cases with enteroviruses (EV70 except one), 141 cases with adenoviruses (types 3, 4, 8 and 19) and 2 cases with HSV. The findings were an interim outline on the etiologic analysis of viral conjunctivitis which has been conducted in Sapporo since 1974. Upon the basis of these findings, improvements were made on some points and the collaborative study continues to be carried out We would like to clarify the problems left unsolved, especially in those patients with new viral agents, such as cox-ackievirus A 24 variant and higher number types of adenoviruses.