1. Departments of AnesthesiologyHoward University College of Medicine, Washington, DC 20059, USA
2. Physiology & Biophysicsthe Sickle Cell Center, Howard University College of Medicine, Washington, DC 20059, USA
3. School of PharmacyHoward University, Washington, DC 20059, USA
4. Department of SurgerySchool of Medicine, Azad University, Mashad, Iran