American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Feb 1995
Comparative StudyEffects of intrapleural heparin or urokinase on the extent of tetracycline-induced pleural disease.
Extravascular fibrin deposition is common at sites of pleural injury and has been related to loculation of pleural fluids. Although thrombolytic therapy has been used to treat pleural loculations, it has not been compared with pleural administration of anticoagulant therapy. We therefore tested interventional strategies designed to compare the relative effects of in vivo anticoagulation or supplemented fibrinolysis on pleural injury, and to characterize the local tissue responses to these modalities. ⋯ Visceral pleural thickness did not differ between groups (p = NS). We conclude that intrapleural heparin or uPA are equally effective in decreasing intrapleural adhesions in tetracycline-induced pleural injury. The data indicate that early anticoagulation or fibrinolytic intervention can attenuate subsequent pleural symphysis in this model.
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Gas and tar phases of commercially available filter cigarettes were tested for ferritin-iron-releasing effects and polyunsaturated-fatty-acid oxidant capacity in vitro. A vacuum pump-dependent apparatus with Cambridge filters was used to separate gas and tar; the former was directly smoked into reaction mixtures, while the latter was extracted from Cambridge filters in aqueous medium and freshly used at 40 to 80% final concentrations. Both phases induced ferritin iron release, which was not antagonized by superoxide dismutase (SOD). ⋯ In the absence of ferritin, gas-induced lipid peroxidation was very low, and tar extracts were apparently ineffective. Thus, the intrinsic lipoperoxidative capacity of cigarette smoke is low and is due to gas; however, when smoke interacts with ferritin, a marked iron-driven peroxidation becomes manifest essentially with gas, tar components acting as antioxidants. The present data suggest that cigarette-smoke-mediated iron mobilization from ferritin may represent a specific prooxidant mechanism related to cigarette smoking in vivo.