[1] Yokohama City Univ, Grad Sch Med, Dept Urol, Yokohama, Kanagawa 232, Japan
[2] Yokohama City Univ, Med Ctr, Dept Urol, Yokohama, Kanagawa 232, Japan
[3] Yokohama City Univ, Med Ctr, Dept Renal Transportat, Yokohama, Kanagawa 232, Japan
[4] Yokohama City Univ, Grad Sch Med, Dept Biostat, Yokohama, Kanagawa 232, Japan
[5] Johns Hopkins Univ, Sch Med, Dept Pathol, Baltimore, MD 21205 USA
[6] Johns Hopkins Univ, Sch Med, Dept Urol, Baltimore, MD 21205 USA