Pulmonary fibrosis was induced in male Sprague-Dawley rats by intratracheal instillation of bleomycin. By 30 d post-bleomycin, the lungs exhibited elevated interstitial collagen levels. Thirty d after exposure to bleomycin, animals were further treated by intratracheal administration of phosphate-buffered saline (PBS) or 12,500 units of recombinant human urokinase (rh-UK). Three days later, the animals were sacrificed and the lungs fixed, sectioned, and assessed for fibrosis. The presence of interstitial collagen was quantitated using a BioQuant Image Analysis System (R and M Biometrics, Inc., Nashville, TN). Urokinase treatment of animals with established pulmonary fibrosis induced by exposure to 0.5 units of bleomycin was found to diminish the collagen content of lungs to near control levels by 3 d post-UK treatment. By 36 d post-UK treatment (66 d post-bleomycin), values for interstitial collagen were again partially elevated, indicating that UK treatment interfered with established fibrosis but did not stop the bleomycin-mediated process. However, the extent of fibrosis was less than that observed in lungs from non-UK treated animals 66 d post-bleomycin. UK treatment initiated 63 d post-bleomycin exposure again revealed a decline in the extent of fibrosis, but the values did not return to baseline levels. A repeat of the short-term experiment with a higher dose of bleomycin (0.85 units) again revealed that UK treatment was effective in diminishing the extent of fibrosis from 22% to 12% collagen. These results indicate that exogenous UK may be an effective therapeutic modality in the treatment of pulmonary fibrosis induced by some stimuli or developing in association with diseases such as scleroderma.

Animals↗

PubMed1993

The risk of sidestream smoke from pipes.

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Humans↗

PubMed1993

Exogenous rh-urokinase modifies inflammation and Pseudomonas aeruginosa infection in a rat chronic pulmonary infection model.

The effect of recombinant human urokinase (rh-UK) in a rat model of chronic Pseudomonas aeruginosa pulmonary infection was studied. Efficacy was assessed by lung histology and quantitative bacteriology. Male Sprague-Dawley rats received 1 x 10(4) or 1 x 10(5) P. aeruginosa encapsulated in agar beads via the intratracheal route on day 1. Intratracheal administration of up to 12,500 units of rh-UK on day 21 led to a dose-dependent disappearance of viable organisms from the lungs by day 24 in rats receiving 10(4) organisms. In slightly longer term infections (30 days), rh-UK was still effective in facilitating the disappearance of the organisms from the lungs of most of the treated animals. rh-UK was effective in eliminating organisms when animals were infected with 10(4), but not 10(5) bacteria. In vitro analysis revealed that rh-UK was not directly toxic for the organisms. Histologically, lungs from short-term infected control animals exhibited acute inflammation, inflammatory cell infiltrates, and fibrin deposition. Histology of lungs from UK-treated, short-term infected rats revealed decreased airway inflammation and cellular infiltration compared with infected controls. Lungs from infected animals treated with 12,500 units of rh-UK were histologically indistinguishable from the lungs of uninfected control animals, except for the foreign body reaction. These results indicate that exogenous rh-UK may be efficacious in the treatment of pulmonary inflammation accompanying exposure to Gram-negative bacteria such as P. aeruginosa.

Animals↗

PubMed1992

Smoking accepted on death certificates.

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Cause of Death↗

PubMed1987

Smoking at work.

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Environmental Pollution↗

PubMed1986

Effects of passive smoking.

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Aged↗

PubMedDate not supplied

Measurement of passive smoking.

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Adult↗