Myeloperoxidase activity in lung homogenates. Saline, low titer hu-IgG, high titer hu-IgG, or anti-PcrV rab-IgG was administered to the mice and their lungs were removed 24 h post-instillation. MPO: myeloperoxidase activity; Dots represent animals. Data are presented as median, first (boxes), and second quartiles (bars) with each value indicated by circles; *, p < 0.05 compared with the saline-premixed group; ‡, p < 0.05 compared with the no bacteria control group.