1. Eugene Marais Hospital, Les Marais, Pretoria, Republic of South Africa
2. North Estonian Regional Hospital, Clinic of Surgery, Tallinn, Estonia
3. P. Stradina Clinical University Hospital, Medical Academy of Latvia, Riga, Latvia
4. Tijger Trial Centre, Karl Bremer and University of Stellenbosch, Bellville, Republic of South Africa
5. Tartu University Clinics, Tartu, Estonia
6. St. Mary's Hospital, Durban, Republic of South Africa
7. Clinical Research and Development, Wyeth Research, Paris, France
8. Clinical Research and Development, Wyeth Research, Collegeville, Pennsylvania