Congested capillaries and swollen endothelium with extensions. Image (A) shows a non-infected control lung with non-congested capillaries. Congested capillaries in ALI/ARDS lungs could be seen by light (B) and TEM (C and D) and were filled with iRBC, niRBC and leukocytes (B, insert). Endothelial cells appeared swollen (C and D), and extensions of the swollen cells could be seen as in Figure (D) where they are sheltering the red blood cell (arrow head). E, endothelium; niRBC, non-infected red blood cell; AS, alveolar space; iRBC, infected red blood cell. Note: (A) is close up of tissue shown in 2B.