[1] ARCISPEDALE SM NUOVA,CUN CHEM LAB,FLORENCE,ITALY
[2] WEIZMANN INST SCI,DEPT HORMONE RES,REHOVOT 76100,ISRAEL
[3] UNIV BOLOGNA,PHYSIOPATHOL REPROD SERV,I-40126 BOLOGNA,ITALY
[4] UNIV LONDON KINGS COLL,SCH MED,DEPT OBSTET & GYNAECOL,LONDON WC2R 2LS,ENGLAND