1. Division of Medical SciencesThe Medical School, Institute of Biomedical Research, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK1Nestle Research CenterPO Box 44, Vers-Chez-Les-Blanc, 1000 Lausanne 26, Switzerland2Pfizer Global Research and DevelopmentLa Jolla Laboratories, 10646 Science Center Drive, San Diego, California 92121, USA