1. Department of Microbiology and Immunology, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania 17033
2. Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
3. Department of Biochemistry, University of Pennsylvania, School of Dental Medicine
4. Biosyn, Inc., Philadelphia, Pennsylvania 19104