1. Department of Surgical and Morphological Sciences, Faculty of Medicine and Surgery, University of Insubria, Varese, Italy.
2. Department of Surgery and Surgical Specialties, University of Modena and Reggio Emilia Medical School, Surgical Clinic, Modena, Italy.
3. Poliambulatorio del Secondo Parere, Modena, Italy.
4. Department of Physiology, School of Medicine, University of Kentucky Medical Center, Lexington, Kentucky.