1. Department of Obstetrics and Gynecology, Faculty of Medicine, Shimane University, 6938501 Izumo, Japan
2. Department of Organ Pathology, Faculty of Medicine, Shimane University, 6938501 Izumo, Japan
3. Division of Cardiovascular and Thoracic Surgery, Department of Surgery, Faculty of Medicine, Shimane University, 6938501 Izumo, Japan