[1] TOKYO MED & DENT UNIV,DEPT MOL VIROL,TOKYO 113,JAPAN
[2] KITASATO UNIV,SCH SCI,DEPT BIOSCI,SAGAMIHARA,KANAGAWA 228,JAPAN
[3] KYUSHU UNIV,DEPT NEUROL,FUKUOKA 812,JAPAN
[4] CENT INST EXPT ANIM,KAWASAKI,KANAGAWA 216,JAPAN
[5] KANAGAWA ACAD SCI & TECHNOL,KAWASAKI,KANAGAWA 213,JAPAN
[6] TOKAI UNIV,DEPT PATHOL,ISEHARA,KANAGAWA 25911,JAPAN
[7] OSAKA UNIV,DEPT BIOREGULAT,SUITA,OSAKA 565,JAPAN