Figure 5: (a) Mononuclear leucocytes infiltration, crypt architectural disarray, and deep mucosal lymphocytosis. (b) Focally there is a moderate epithelial regeneratory atypia simulating dysplasia (arrow). Kreyberg trichrom stain (acid mucopolysaccharides are stained blue). C57BL/6JOlaHsd male mice are exposed to 3% DSS solution for 5 days followed by drinking water for 28 days.