[1] NIH, Program Reprod & Adult Endocrinol, NICHHD, Bethesda, MD 20892 USA
[2] Massachusetts Gen Hosp, Neuroendocrine Unit, Boston, MA 02114 USA
[3] Med Coll Wisconsin, Milwaukee, WI 53226 USA
[4] Univ Sheffield, Sheffield S10 2JF, S Yorkshire, England
[5] Univ London, William Harvey Res Inst, London EC1M 6BQ, England
[6] Mayo Clin, Rochester, MN 55905 USA
[7] Univ Birmingham, Birmingham B15 2TT, W Midlands, England