1. Department of Medicine, Hamad Medical Corporation, Doha, Qatar
2. Department of Internal Medicine, Tripoli Central Hospital, Tripoli, Libya
3. Department of Nephrology, Tripoli Children Hospital, Tripoli, Libya
4. Department of Medicine, Faculty of Medicine, University of Tripoli, Tripoli, Libya
5. Department of Medicine, Hamad Hamad Medical Corporation, College of Medicine, Qatar University, Doha, Qatar