1. a Department of Epidemiology, School of Public Health , University of Alabama , (UAB), Birmingham , USA
2. b Division of Preventive Medicine, Department of Medicine , UAB
3. c Center for AIDS Research , UAB , USA
4. d Glaxo-Wellcome, Inc , USA
5. e Comprehensive Cancer Center , UAB , USA
6. f Division of Infectious Diseases, Department of Medicine , UAB , USA