1. Department of Internal Medicine, Eisenhower Medical Center, California, USA
2. Research Development Center, Department of Cardiology, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
3. Department of Internal Medicine, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
4. Research Development Center, Sina Hospital; Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran, Iran
5. Knowledge Utilization Research Center, Tehran University of Medical Sciences, Tehran, Iran