Cellular distribution of pulmonary Mn and CuZn superoxide dismutase: effect of hyperoxia and interleukin-1

Pulmonary superoxide dismutase (SOD) plays an important role in the lung defense against O2 toxicity. We have previously demonstrated that tracheal insufflation of interleukin-1 alpha (IL-1) selectively enhances pulmonary MnSOD and protects rats against O2 toxicity. However, little is known about the cellular distribution of pulmonary MnSOD- and CuZnSOD-specific proteins. We performed immunohistochemistry in plastic sections (2 microns thick) to determine the effects of hyperoxia and IL-1 on the cellular distribution of pulmonary MnSOD and CuZnSOD in rats. MnSOD and CuZnSOD were present in all lung cells. Smooth muscle and endothelial cells appeared to contain higher immunoreactive MnSOD and CuZnSOD proteins than other lung cell types. Exposure of rats to 100% O2 for 24 hr had no effect on the cellular distribution and intensity of pulmonary MnSOD. However, at 50 hr after O2 exposure the intensity of pulmonary MnSOD was reduced. In contrast, tracheal insufflation of IL-1 markedly enhanced the intensity of pulmonary MnSOD in rats exposed to O2 for 50 hr. Neither O2 exposure nor IL-1 insufflation had any apparent effect on the distribution and intensity of pulmonary CuZnSOD. We conclude that IL-1 selectively enhances pulmonary MnSOD and that this effect is manifested in most lung cells, particularly smooth muscle and endothelial cells.     

Vaginal colonization with Group B beta-hemolytic streptococcus as a risk factor for post-cesarean section febrile morbidity

Vaginal colonization of mothers with Group B beta-hemolytic streptococcus (GBS) has been recognized as a risk factor for neonatal morbidity. The relationship of GBS colonization to risks for the mother who undergoes cesarean section has not been defined. In this study, we found that, among patients who underwent cesarean section, the 19% of them who were colonized with GBS had a higher incidence of standard fever (66.6% vs. 30.5%), clinical diagnosis of endomyometritis (61.1% vs. 12.5%), and use of antibiotics (61.1% vs. 26.3%) in relationship to a significantly increased frequency of premature rupture of the membranes (50.0% vs. 14.8%). Reasons for the association between vaginal colonization and increased morbidity are discussed.