- Human immunodeficiency virus type 1 (HIV-1) strains selected for resistance against the HIV-1-specific [2',5'-bis-O-(tert-butyldimethylsilyl)-3'-spiro- 5''-(4''-amino-1'',2''-oxathiole-2'',2''-dioxide)]-beta-D-pentofurano syl (TSAO) nucleoside analogues retain sensitivity to HIV-1-specific nonnucleoside inhibitors. Balzarini, J., Karlsson, A., Vandamme, A.M., Pérez-Pérez, M.J., Zhang, H., Vrang, L., Oberg, B., Bäckbro, K., Unge, T., San-Félix, A. Proc. Natl. Acad. Sci. U.S.A. (1993)