Overlapping bouts of inflammation induce more DSBs than independent bouts of inflammation.

<p>Inflammation, cell proliferation and γH2AX foci formation were quantified in pancreas sections from mice treated with independent bouts of inflammation (blue bars) and with overlapping bouts of inflammation (purple bars). (<b>A,B</b>) Cerulein induces inflammation in both independent (n = 7) and overlapping (n = 8) treatment regimens. Severity of inflammation in control and cerulein-treated mice was quantified by a trained pathologist. (<b>C, D</b>) Quantification of nuclei positive for the proliferation marker Ki-67 shows a moderate increase in independent bouts of inflammation (n = 7), and a large increase in overlapping bouts of inflammation (n = 8). (<b>E,F</b>) Quantification of nuclei positive for the DSB marker γH2AX (nuclei with >5 foci) shows a moderate increase in independent bouts of inflammation (n = 3), and a large increase in overlapping bouts of inflammation (n = 3). Data are mean ± SEM. See <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004901#sec004" target="_blank"><i>Methods</i></a> for detailed pathological scoring criteria. Statistical testing could not be performed in groups containing only zero values. * <i>P</i> < 0.05; ** <i>P</i> < 0.01, *** <i>P</i> < 0.001 (Student’s <i>t</i>-test).