Histological examination of lung tissue. Tissues from pre-terminal bronchioles were analyzed for morphologic features, mucosubstances in mucous cells and the presence of some proteins associated with allergic lung inflammation. (A-C) H&E staining. (D-E) AB/PAS staining. Arrows depict AB/PAS-stained mucosubstances in airway epithelium. (G-I) Immunohistological staining using anti Ym1/Ym2 antibodies. Arrows depict stained Ym1/Ym2. (J-L) Immunohistological staining using anti FIZZ1 antibodies. Arrows depict FIZZ in the epithelium. Abbreviations: AB/PAS, Alcian blue-Periodic acid schiff double stain; AL, airway lumen; ap, alveolar parenchyma; bv, blood vessel; e, airway surface epithelium; H&E, hematoxylin and eosin stain.