1. Center for Infectious Disease, School of Public Health and Medical School, University of Texas—Houston,1
2. University of Texas M.D. Anderson Cancer Center,2 and
3. Alfa Wassermann, S.p.A. Bologna, Italy3; and
4. Salix Pharmaceuticals Inc., Palo Alto, California4
5. St. Luke's Episcopal Hospital and Baylor College of Medicine,5 Houston, Texas;