Figure 1

Morphology and immunohistochemistry of COPD-associated lung lesions. A: Chronic bronchitis. B: Centriacinar emphysema. C: Advanced active bronchitis with fibrosis and emphysema. A-C, hematoxylin-eosin staining; D: CD68-PPARG coexpression with double IHC staining using alkaline phosphatase [red cytoplasm-CD68] and diamino-benzidine [brown nuclei-PPARG]. E: Cells with red fluorescence and green nuclei DCSign-PPARG double fluorescence staining. Nuclear counter-staining is DAPI. Indications: b, bronchus; a, alveolar spaces; arrows, alveolar macrophages. Original magnifications: A-D 20×; E 40×;