Fig. 4.

Extracellular DNA concentration in pleural fluids of humans and rabbits with EMP. A: semilogarithmic plot of DNA concentration (μg/ml) in human (prospectively collected at UTHSCT and MIST2) and rabbit P. multocida and S. pneumoniae-induced EMP pleural fluids. Total nucleic acids were purified from 100 μl of pleural fluid by using a DNeasy blood and tissue kit from Qiagen as described in the manufacturer's protocol. The amounts and size distribution of DNA were estimated by A₂₆₀ (A) and agarose gel electrophoresis (B). Lane 1, Human UTHSCT; lane 2, human MIST2; lane 3, rabbit with P. multocida EMP; lane 4, rabbit with S. pneumoniae EMP. The reassembly of noncontiguous gel lanes is demarcated by white spaces. Gels were visualized and analyzed by using a Molecular Imager supplemented with Quantity One (version 4.2.3) software (Bio-Rad). Data are presented as box plots (showing interquartile ranges). Results for Kruskal-Wallis test presented statistically significant difference in the mean values among the treatment groups (P < 0.001). Pairwise multiple comparison showed that the concentration of DNA in the P. multocida pleural injury group is statistically higher among the analyzed groups (P < 0.001).