1. Cell Biology and Histochemistry Division, Zoology Department, Faculty of Science, South Valley University, Qena, Egypt
2. Physiology Division, Zoology Department, Faculty of Science, Beni-Suef University, Salah Salem Street, P.O. Box 62514, Beni-Suef, Egypt
3. Faculty of Oral and Dental Medicine, Nahda University, New Beni-Suef City, Beni-Suef, Egypt
4. Diabetes Research Institute, Düsseldorf, Germany