Department of Modern Sciences and Technologies, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Department of Pharmacology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Student Research Committee, Department of Modern Sciences and Technologies, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Department of Biochemistry, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Division of Medical Education, Brighton and Sussex Medical School, Falmer, Brighton, Sussex, BN1 9PH, UK. Biochemistry and Nutrition Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Biotechnology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.