Correspondence to: Mohammed Elmujtba Adam Essa Adam, Medical and Cancer Research Institute (MCRI), Department of Clinical Medicine, Faculty of Medicine, AlFashir University, AlFashir, Sudan. Tel: +249907009378, E-mail:
Awadali818@yahoo.com; Ziryab Imad Taha, Department of Internal Medicine, Faculty of Medicine, University of Bahri, Khartoum, Sudan, Tel: +249912129921, E-mail:
Ziryab2008@yahoo.com; Abdelkareem Abdallah Ahmed, Department of Physiology and Biochemistry, Faculty of Veterinary Science, University of Nyala, Nyala, P.O. Box: 155 Nyala, Sudan. Fax: +249711833123, E-mail:
kareemo151@gmail.com