Fig. 5

A–C Electron photomicrographs of the CG showing: A Interalveolar septum with few interstitial cells (IS) and patent alveoli (PA) lined by flatted type I (P1) and club-shaped type II pneumocyte (P2). Double arrow; thin blood-air barrier. B Type I pneumocyte showing flattened euchromatic nucleus (N). Bc; blood capillary, PA; patent alveoli. C Type II pneumocyte (P2) showing prominent microvillous border (MV), euchromatic nucleus (N), mitochondria (m) and multiple lamellar bodies (LB). Intercellular junction (J) is seen between the two types of pneumocytes. Notice the thin blood-air barrier (double arrow). PA; patent alveoli. Scale bar A–C 2 µm. D–G Electron photomicrographs of HG showing D The IAS is obviously thickened, fibroblasts (F) surrounded by collagen (C) and some interstitial cells have small heterochromatic nuclei (N) were also seen. Multiple type II pneumocytes (P2) with almost empty lamellar bodies (LB) and absent microvilli (MV) are seen. Notice a desquamated type II pneumocyte into the alveolar lumen (arrowhead). P1; type I pneumocyte. E Type I pneumocyte (P1) with irregular heterochromatic nucleus and dense cytoplasm. F; fibroblast surrounded by collagen fibrils (C). EL; elastic fibers, IS; interstitial cell (star); interstitial oedema. F Type II pneumocyte (P2) with an irregular heterochromatic nucleus and blunted microvillus border (MV). Extensive collagen deposition (C) in the vicinity of a fibroblast (F) is also seen. G Type I pneumocyte (P1) with irregular heterochromatic nucleus. Type II pneumocyte (P2) showing heterochromatic nucleus and blunted microvillous border (MV). A cell in the process of apoptosis with multiple apoptotic bodies (arrow) and peripheral nuclear chromatin clumps (N) is also seen. BC; blood capillary, IS; interstitial cell, star; interstitial oedema. Scale bar D 5 µm (E, F, G) 2 µm. H–L Electron photomicrographs of CFM -TG showing: H: Multiple ISCs showing irregular heterochromatic nuclei, and some surrounded with collagen fibrils (C). P1; type I pneumocyte, P2; type II pneumocyte, E; endothelial cell, star; interstitial oedema. I Multiple type II pneumocytes having small irregular nuclei (N) and empty lamellar bodies (LB). Many interstitial cells (IS) are also seen. C; collagen. MV; microvilli. CA; collapsed alveolus. J Type I pneumocyte with irregular surface. A; alveolus, C; collagen, star; interstitial oedema. K Type II pneumocyte with irregular heterochromatic nucleus and mildly dilated perinuclear cisterna (arrow). LB; lamellar body. C; Collagen, EL; elastic fibers. L Type II pneumocyte (P2) having empty lamellar body (LB). CA; Collapsed alveolus, RBC; an extravasated red blood corpuscle into the alveolar lumen. Scale bar H, I 5 µm, J–L 2 µm. n = 10 in all groups