1. Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
2. The First Affiliated Hospital of San Yat-Sen University, Guangzhou, China.
3. Department of Internal Medicine, Chosun University College of Medicine, Gwangju, Korea.
4. Department of Internal Medicine, Kyung Hee University College of Medicine, Seoul, Korea.
5. Department of Internal Medicine, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea.