Affiliation: | 1. Departments of Obstetrics and Gynecology, and Laboratory Medicine, University of Nebraska Medical Center, 42nd and Dewey Avenue, Omaha, Nebraska 68105 U.S.A.;2. Departments of Biochemistry, and Pathology and Laboratory Medicine, University of Nebraska Medical Center, 42nd and Dewey Avenue, Omaha, Nebraska 68105 U.S.A. |