1. Department of Medicine, Division of Nephrology; University of Würzburg; Würzburg
2. Department of Nephrology Hôpital Lapeyronie; University of Montpellier; Montpellier; France
3. Research and Development; Membrana GmbH; Wuppertal
4. Dialysis Center; Elsenfeld
5. Hamburger Dialyse Lohbrügge; Hamburg
6. KfH Center; Aschaffenburg; Germany