Lung pathohistology photomicrographs. Representative examples of the stained specimen slides show the inflammation in the murine lungs 48 h after an intratracheal infection with 6.0 × 105 CFU of P. aeruginosa. Slides A-E represent different degrees of inflammation as they were assessed in the semi-quantitative pathohistological score; control (F). Hematoxilin-eosin staining; scale bar: 100 μm. A) Profound purulent pneumonia in an old FABP WT mouse, massive inflammatory infiltrates within the alveolae and intrabronchiolar (arrow), B) Old FABP WT mouse showing moderate inflammation with peri- and minor intrabronchiolar (arrowhead) leucocyte accumulation, C) Peribronchiolar and perivascular inflammation accompanied by inflammatory edema (arrow) in a young CftrMHH mouse D) Old CftrKO mouse: Strong leucocyte accumulation (arrow) around a lung vessel, E) Only faint peribronchiolar inflammation in an old CftrMHH F) Control: normal lung parenchyma.