1. Faculty of Medicine, Tanta University, Tanta, Egypt
2. Department of Medicine, University of Missouri, Kansas City, USA
3. Faculty of Medicine, Islamic University of Gaza, Gaza, Palestine
4. Faculty of Medicine, Minia University, Minia, Egypt
5. Department of Medicine, University of Texas, MD Anderson Cancer Center, Texas
6. Department of Internal Medicine, McLaren Health Care, Flint, Michigan
7. Department of Internal Medicine, Michigan State University, East Lansing, Michigan
8. Baylor College of Medicine, Texas