1. Semmelweis University, Budapest, Hungary;
2. Hemodialysis Unit, Fresenius Medical Care, Budapest, Hungary;
3. Medical Services, Ralph H. Johnson VA Medical Center, Charleston, SC, USA;
4. Hemodialysis Unit, Fresenius Medical Care Hungary, Hatvan, Hungary;
5. Hemodialysis Unit, Fresenius Medical Care Hungary, Cegléd, Hungary;
6. 1st Department of Internal Medicine, Faculty of Medicine, Semmelweis University, Budapest, Hungary;
7. Department of Pathophysiology, International Nephrology Research and Training Center, Semmelweis University, Budapest, Hungary;
8. Department of Medicine, Division of Nephrology, Medical University of South Carolina, Charleston, SC, USA