1. Department of Surgery, Kuopio University Hospital, Kuopio, Finland.
2. Department of Microbiology and Immunology, University of Turku, Turku, Finland.
3. Department of Physiology and Biocenter of Oulu, Oulu University, Oulu, Finland, and Department of Psychiatry, Kuopio University Hospital, Kuopio, Finland.
4. Division of Surgery, Gastroenterology and Oncology, University Hospital of Tampere, Tampere, Finland.
5. Department of Surgery, Turku University Hospital, Turku, Finland.