1. Department of Pathology, Medical College of Wisconsin,1
2. Pathology and Laboratory Medicine Service, Department of Veterans Affairs Medical Center,2 and
3. Gastroenterology Diagnostic Unit, University of Wisconsin Medical School—Milwaukee,3 Milwaukee, Wisconsin;
4. Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland4; and
5. Department of Cell Biology and Physiology, Washington University, St. Louis, Missouri5