[1] UNIV TOKYO,INST MED SCI,DEPT VIRAL INFECT,MINATO KU,TOKYO 108,JAPAN
[2] UNIV TOKYO,FAC MED,DEPT UROL,BRANCH HOSP,BUNKYO KU,TOKYO 112,JAPAN
[3] UNIV TOKYO,FAC MED,DEPT UROL,BUNKYO KU,TOKYO 113,JAPAN
[4] KITASATO UNIV,DEPT MICROBIOL,SCH ALLIED HLTH SCI,SAGAMIHARA,KANAGAWA 228,JAPAN