1. Department of Haematology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia
2. Department of Biology, Faculty of Education, Omdurman Islamic University, Omdurman P.O. Box 382, Sudan
3. Department of Internal Medicine, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Kelantan, Malaysia