1. Division of Urology, Duke University Medical Center, Durham, North Carolina
2. Department of Urology, Naval Medical Center, San Diego, California
3. Department of Urology, National Naval Medical Center, Bethesda, Maryland
4. Urologic Specialists of Oklahoma, Tulsa, Oklahoma
5. Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
6. Division of Pediatric Urology, Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania