Lung histology. Photomicrographs of hematoxylin - and eosin-stained left lung lower lobe specimens from sheep subjected to right pneumonectomy followed by an 8 h period of one-lung ventilation. Magnification x 25 (left). Areas within the squares are magnified x 100 (right). Panel A: protective ventilation (PROTV group) showing no pathologic changes. Panel B: injurious ventilation (INJV group). Panel C: injurious ventilation followed by intravenous infusion of 7-nitroindazole (INJV + NI group). Atelectasis (atl), interstitial edema with thickening of interalveolar - and interlobular septa (ias and ils), thickening of the subpleural interstitium (spi), extravasation of neutrophils (arrows), formation of hyaline membranes (hm).