[1] Univ Munich, Dept Urol, D-81377 Munich, Germany
[2] Royal Hallamshire Hosp, Sheffield S10 2JF, S Yorkshire, England
[3] Vanderbilt Univ, Med Ctr, Nashville, TN USA
[4] Natl Hosp Neurol & Neurosurg, London WC1N 3BG, England
[5] Univ Texas SW Med Ctr Dallas, Dallas, TX 75390 USA
[6] Wake Forest Inst Regenerat Med, Winston Salem, NC USA