Thickening of septa in ALI/ARDS lungs. Light microscopy images of HE-stained, non-infected (A) and ALI/ARDS lungs (C). Septa of ALI/ARDS lungs were 80% thicker (B) than those of non-infected control lungs, mean (SEM), n = 5/group. ALI/ARDS lung image by TEM, showing oedema and thickened septa containing congested capillaries and leukocytes (D). ALI/ARDS lung, lung from DBA/2 mouse that died with acute lung injury/acute respiratory distress syndrome after infection with P. berghei ANKA. Ly, lymphocyte; Mφ, macrophage; N, neutrophil; AS, alveolar space; EPII, epithelium type II.