1. Equipe “Endotoxines” du C.N.R.S. (U.R.A. 1116), Université de Paris-Sud, Centre d’Etudes Pharmaceutiques, 92296 Châtenay-Malabry, France, and Institute of Biochemistry, Faculty of Sciences, University of Debrecen, P.O. Box 55, H-4010 Debrecen, Hungary