1. University College of Medicine and Dentistry, University of Lahore, Lahore, Pakistan
2. Karachi Medical and Dental College, Karachi, Pakistan
3. Faculty of Medicine, Fayoum University, Fayoum, Egypt
4. Faculty of Medicine, Zagazig University, Zagazig, Egypt
5. Faculty of Medicine, University of Aleppo, Aleppo, Syria