[1] Univ Colorado, Sch Med, Denver, CO USA
[2] Methodist Childrens Hosp, Lubbock, TX 79410 USA
[3] Osped Circolo, Div Urol, Varese, Italy
[4] Univ Calif Los Angeles, Div Urol, Los Angeles, CA USA
[5] Kaiser Permanente Med Ctr, Los Angeles, CA 90034 USA
[6] Brown Univ, Sch Med, Hasbro Childrens Hosp, Div Urol, Providence, RI 02912 USA