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@#Objective - To establish a new non exposed intratracheal instillation method for establishing a rat silicosis model. Methods ， The specific pathogen free SD rats were randomly divided into control group and experimental group with ten rats in ， each group. Rats in the control group were given 1.0 mL of 0.9% sodium chloride solution and rats in the experimental group - were given 1.0 mL of silica suspension with a mass concentration of 50 g/L adopting to the one time intratracheal instillation ， - ， method and then followed by ventilator assisted ventilation immediately. When the tidal volume stabilized at 2.0 mL the ventilator was removed and the tracheal intubation was pulled out. Five rats in each group were sacrificed after two and four ， - Results weeks after modeling and hematoxylin eosin staining and Masson staining of lung tissue were performed. There was ， ， no death in the two groups of rats during the experiment. After two and four weeks the control group had normal lung structure ， ， ， normal alveolar cavity size no inflammatory cell infiltration thin alveolar wall only a small amount of collagen distribution ， around the lung interstitium and bronchus. At the second week of modeling the alveolar wall of the rats in the experimental ， ， ， group was slightly thickened interstitial lymphocytes and macrophages were infiltrated slight hyperplasia was found and a ， small amount of fibroblasts were visible. At the 4th week of modeling the alveolar wall of the rats in the experimental group was ， ， ， ， significantly thickened fibrous nodules were formed and fibroblasts fibrocytes collagen fibers were significantly increased. Conclusion - The combination of ventilator and non exposed intratracheal instillation method can be used to successfully ， ， . establish a rat silicosis model which is simple safe and effective
RESUMO
<p><b>OBJECTIVE</b>To evaluate the alterations of biomarkers in the development and progression of coal workers' pneumoconiosis (CWP).</p><p><b>METHODS</b>The type and number of cells, and the levels of tumor necrosis factor-alpha (TNF-alpha), pulmonary surfactant protein, phospholipids and fibronectin in bronchoalveolar lavage fluid were assayed in 14 health active coal miners, 21 coal miners without CWP and 13 miners with CWP of 0/1 to 1/1.</p><p><b>RESULTS</b>Compared to active coal miners without CWP (8.23 microg/mL), TNF-alpha concentration was gradually decreased when dust exposure was stopped (5.90 microg/mL). Elevated surfactant protein A (SP-A) level and phosphatidylglycerol (PG) to phosphatidylinositol (PI) ratio were found in miners actively exposed to coal dust (6528 ng/mL for SP-A and 10. for PG/PI), and both parameters decreased when CWP progressed from CWP (0/1) (3419 microg/mL for SP-A and 5.9 for PG/PI) to CWP (1/1) (1654 microg/mL for SP-A and 5.5 for PG/PI).</p><p><b>CONCLUSION</b>Biomarkers in bronchoalveolar lavage fluid can be used to screen coal miners at high risk of developing coal workers' pneumoconiosis.</p>