1. Virology Laboratory, Pathology Laboratory and Infectious Diseases Clinic, School of Medicine, "Gr. T. Popa" University of Iasi, Iasi, Romania; and AIDS Animal Models Laboratory, Tulane National Primate Research Center, Covington, Louisiana 70433
2. Laboratoire de Virologie, Hopital Bichat-Claude Bernard, Paris, France
3. School of Biological Sciences, University of Manchester, Manchester, UK
4. Virology Laboratory, Pathology Laboratory and Infectious Diseases Clinic, School of Medicine, "Gr. T. Popa" University of Iasi, Iasi, Romania