Fig. 1
From: Mucosal eosinophilic infiltration may be a characteristic of human intestinal spirochetosis
Histology of HIS specimens. A-C. Histology of hematoxylin & eosin (A) and Giemsa-stained (B & C) sections revealed neutrophils (white arrowheads), eosinophils (yellow arrowheads), and a metachromatic mast cell (red arrowhead in C). Histology also displayed hematoxylinophilic structures (i.e., fringes) covering the surface epithelium (black arrowheads in A). D-H Immunohistochemistry using anti-Treponema pallidum antibody showed many immunopositive spiral bacteria within the attached mucus and epithelial layer in HIS samples (D: positive control section). This was almost negative and no spiral bacteria were evident in non-HIS samples (E: negative control section). Immunohistochemistry revealed thick, band-like fringes on the surface epithelium (black arrowheads in F) and spiral organisms either within the crypt lumens (blue arrows in G) or within the surface epithelial layers (blue arrows in H). A: hematoxylin & eosin, × 400; B & C: Giemsa, × 400; D-F: diaminobenzidine, D × 200, F × 100, E, G & H × 400