1. Department of Internal Medicine and Oncology, Faculty of Medicine, Semmelweis University, 1085 Budapest, Hungary
2. Department of Nephrology, Szent Margit Kórhaz, 1032 Budapest, Hungary
3. Medicine Service, Ralph H. Jonson VA Medical Center, Charleston, SC 29401, USA
4. Department of Medicine, Division of Nephrology, University of Maryland Medical Center, Baltimore, MD 21201, USA
5. Department of Medicine, Division of Nephrology, Medical University of South Carolina, Charleston, SC 29425, USA