1. Department of Internal Medicine, University at Buffalo, Buffalo, New York, USA.
2. Department of Internal Medicine, United Health Services, Johnson City, New York, USA.
3. Faculty of Medicine, Minia University, Minia, Egypt.
4. Department of Internal Medicine, Marshall University Joan C. Edwards School of Medicine, Huntington, West Virginia, USA.
5. Department of Internal Medicine, Rochester General Hospital, Rochester, New York, USA.
6. Faculty of Medicine, Al-Azhar University, Cairo, Egypt.
7. Faculty of Medicine, October 6 University, Giza, Egypt.
8. Faculty of Medicine, Benha University, Qalubiya, Egypt.