1. Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryland 21201.
2. Profectus Biosciences, Inc., Baltimore, Maryland 21227.
3. Gentara Corporation, Malvern, Pennsylvania 19355.
4. Praecis Pharmaceuticals Inc., Waltham, Massachusetts 02451.
5. Institute of Human Virology, Baltimore, Maryland 21201.