1. The Randall Institute, King's College London, 26-29 Drury Lane, London WC2B 5RL, U.K., Anti-Infectives Research, SmithKline Beecham Pharmaceuticals, 1250 South Collegeville Road, P.O. Box 5089, Collegeville, Pennsylvania 19426-0989, and SmithKline Beecham Pharmaceuticals, New Frontiers Science Park (North), Harlow, Essex CM19 5AW, U.K.