1. Department of Pharmaceutical Sciences, University of Brasília (F.A.R.N., L.A.S., R.C.J.R.), Brasília, DF 70910-900, Brazil
2. Veterans Affairs Medical Center (R.R.C.), University of California, San Francisco, California 94143
3. Metabolic Research Unit (D.G.G., J.D.B.), University of California, San Francisco, California 94143
4. Chiron Corp. (B.F.S.), Emeryville, California 94608
5. Department of Biology, University of Cergy-Pontoise (N.L.), Paris, France