1. Medical Research Group of Egypt, Cairo, Egypt
2. Faculty of Medicine, Fayoum University, Fayoum, Egypt
3. Faculty of Medicine, Al-Azhar University, Cairo, Egypt
4. Faculty of Medicine, Zagazig University, Zagazig, Egypt
5. Faculty of Medicine, University of Oran 1 Ahmed Ben Bella, Oran, Algeria
6. Faculty of Medicine, Elrazi University, Khartoum, Sudan.