We studied the effects of bovine catalase on increased lung vascular permeability to fluid and protein during air emboli in unanesthetized sheep. Pulmonary arterial and left atrial pressures, cardiac output, lung lymph flow, lymph and plasma protein concentrations, arterial PO2, and numbers of arterial leukocytes were measured in paired experiments in which each sheep served as its own control. We found an increase in protein-rich lung lymph flow during embolization in untreated sheep, indicating an increase in microvascular permeability. When sheep were pretreated with intraperitoneal injections of catalase (50 mg/kg divided over the 24 h before air infusion), vascular pressures, arterial PO2, and leukocyte counts were not different from when the sheep were untreated, but the expected increases in transvascular fluid and protein flow during emboli were significantly attenuated (by approximately 50%). This effect required catalase enzyme activity, as demonstrated by the failure of enzymatically inactivated catalase (by reaction in vitro with aminotriazole in the presence of H2O2) or catalase vehicle (0.1% thymol in water) to affect the lung lymph response to air emboli. We conclude that H2O2 plays a role in the pathogenesis of the acute lung injury caused by intravenous air infusions into unanesthetized sheep. Because both catalase and superoxide dismutase have protected sheep lungs from air emboli-induced increased vascular permeability, a possible specific cause of microvascular barrier injury could be hydroxyl radicals formed from reactions between H2O2 and superoxide anion.
This Case Report is that of a young woman followed for 21 years, whose life was saved repeatedly by bronchoscopy and lavage to remove mucous plugs and casts from the tracheobronchial tree. In 1982, after again having a respiratory crisis and not having a bronchoscopy and lavage, she died. The pathology revealed a thickened hyalinized basement membrane and numerous mucous plugs filling the larger bronchi and bronchioles.
Erosion and fistula formation can present more than two decades after using permanent material in pelvic reconstructive surgery. These complications should be included in the differential diagnosis of unexplained pelvic symptoms.
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