1. Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
2. Colorectal Research Center, Iran University of Medical Sciences, Tehran, Iran
3. Liver and Digestive Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
4. Department of Medicine, Tehran University of Medical Sciences, Tehran, Iran
5. Department of Orthopedics and Neurosurgery, Rothman Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
6. Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USA
7. Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran
8. Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Tehran, Iran, and with the Brain and Spinal Injuries Research Center (BASIR), Neuroscience Institute, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran