The world's largest organization of surgeons has accepted the resignation of its president-elect after he wrote a Valentine's Day column for the group's newspaper that some members found demeaning to women. Dr. Lazar J. Greenfield, a renowned surgeon and professor emeritus at the University of Michigan Medical School, said Monday he had stepped down from his leadership post with the American College of Surgeons after the association's board rejected his attempts to make amends. His column divided the 77,000-member group, with some saying it insulted women and exposed a male-dominated culture within the profession. Greenfield's defenders said he had encouraged many aspiring women surgeons and accused his critics of overreacting to a clumsy attempt at humor. In the Surgery News editorial, Greenfield described semen as a mood enhancer for women and referred to a scientific study that described female college students who had unprotected sex as less depressed than those whose partners used condoms.