1. Division of Nephrology, Department of Medicine, Chosun University Hospital, Chosun University School of Medicine, Gwangju 61453, Republic of Korea
2. Department of Obstetrics and Gynecology, Chung-Ang University Gwang-myung Hospital, Chung-Ang University College of Medicine, Gwangmyeong-si 14353, Republic of Korea
3. Department of Physiology, Dong-A University College of Medicine, Busan 49201, Republic of Korea