1. Department of Gastroenterology and Hepatology; University Hospital Essen; Hufelandstrasse 55 Essen 45147 Germany
2. Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health; National Institutes of Health; Bethesda Maryland 20892
3. Laboratory of Immunopathogenesis and Bioinformatics; SAIC-Frederick, Inc., National Cancer Institute at Frederick; Frederick Maryland 21702
4. Department of Psychiatry; University of North Carolina at Chapel Hill; Chapel Hill North Carolina 27599-7305
5. Laboratory of Immunoregulation, National Institute of Allergy, Infectious Diseases; National Institutes of Health; Bethesda Maryland 20892