Fig. 6.

Histology of organotypic cultured bronchial tissues after a one-month period of repeated CSE exposure. Hematoxylin and eosin staining was performed after exposing the organotypic bronchial tissue cultures to each concentration of cigarette smoke extract (CSE) for one month. (A–D) Representative histology images from tissue exposed to 0 (A), 5 (B), 10 (C), or 20 (D) μg/ml CSE. (E–F) Images of abnormal morphology focally observed in tissue exposed to 20 μg/ml CSE. The scale bar indicates 100 μm. Histology images from tissue exposed to 1 μg/ml CSE is not prepared due to technical failure.