[1] UNIV CALIF SAN FRANCISCO, SAN FRANCISCO GEN HOSP, DEPT PATHOL, SAN FRANCISCO, CA 94143 USA
[2] UNIV CALIF SAN FRANCISCO, DEPT DERMATOL, SAN FRANCISCO, CA 94143 USA
[3] UNIV CALIF SAN FRANCISCO, DEPT MED, SAN FRANCISCO, CA 94143 USA
[4] UNIV CALIF SAN FRANCISCO, DEPT ORAL & MAXILLOFACIAL SURG, SAN FRANCISCO, CA 94143 USA
[5] VIROLAB, BERKELEY, CA 94710 USA