1. Population Council (S.S.W.C., M.-y.M., C.Y.C.), Center for Biomedical Research, New York, New York 10021
2. Department of Zoology (S.S.W.C., W.M.L.), The University of Hong Kong, Hong Kong, China
3. Institute of Pharmacology and Pharmacognosy (B.S.), University of Rome “La Sapienza,” 00185 Rome, Italy