[1] NATL INST HLTH,HEPATITIS VIRUSES LAB 2,DEPT ENTEROVIRUSES,2-10-35 KAMIOSAKI,TOKYO 141,JAPAN
[2] NATL INST HLTH,DEPT VET MED,SHINAGAWA KU,TOKYO 141,JAPAN
[3] NATL INST HLTH,DEPT MED ENTOMOL,SHINAGAWA KU,TOKYO 141,JAPAN
[4] ST MARIANNA MED UNIV,SCH MED,KAWASAKI 216,JAPAN
[5] SCI UNIV TOKYO,DEPT BIOL SCI & TECHNOL,NODA,CHIBA 278,JAPAN
[6] UNIV TOKYO,INST MED SCI,MOLEC GENET LAB,MINATO KU,TOKYO 108,JAPAN