Fig. 6

Gastric mucosal defect, dog. a Absence of lining epithelium, presence of bleeding ulcer, and mononuclear inflammatory cell infiltration in periglandular connective tissue in the control group. b Regenerated lining epithelium, hypervascularization of underlying tissue, and presence of mononuclear inflammatory cell infiltration in periglandular connective tissue (H&E × 200). c Poorly observed bluish stained connective tissue in mucosa of control ulcer. d Fine fibers of connective tissue below regenerated epithelium in the gastric ulcer with AM graft (Masson’s trichrome × 200). e Negative staining of collagen IA1 in the exposed granulation tissue in the control ulcer and f negative staining of subepithelial connective tissue in the gastric ulcer with AM graft (avidin–biotin–peroxidase complex method, hematoxylin counterstain × 400)