1. Division of Periodontics Section of Oral, Diagnostic and Rehabilitation Sciences College of Dental Medicine Columbia University Irving Medical Center New York New York USA
2. Department of Microbiology & Immunology Vagelos College of Physicians & Surgeons Columbia University Irving Medical Center New York New York USA
3. Department of Obstetrics & Gynecology Vagelos College of Physicians & Surgeons Columbia University Irving Medical Center New York New York USA