1. Division of Nephrology, Department of Internal Medicine, Keelung Chang Gung Memorial Hospital, Keelung 204, Taiwan
2. College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
3. Community Medicine Research Center, Keelung Chang Gung Memorial Hospital, Keelung 204, Taiwan
4. Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
5. Department of Chemistry, Tamkang University, No. 151, Ying-Chuan Road, Tamsui, New Taipei City 251, Taiwan
6. Department of Medical Research, Koo Foundation Sun Yat-Sen Cancer Center, Taipei 112, Taiwan