1. Department of Applied Bioscience, Research Institute, University of Osaka Prefecture, Shinke-cho, Sakai, Osaka 593, Japan
2. Department of Veterinary Radiology, University of Osaka Prefecture, Sakai, Osaka 591, Japan
3. Department of Pathology, Nara Medical University, Kashiwara 634, Japan
4. Research Laboratory for Oncological Gynecology, Department of Obstetrics and Gynecology, Academisch Ziekenhuis Vrije Universiteit, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands