1. Section of Oncology-Hematology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198-7680, USA
2. Department of Internal Medicine, Creighton University School of Medicine, Omaha, NE 68131, USA
3. Urologic Surgery Section, Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68198-2360, USA