Objective To observe the effects and mechanism of uranium dust on collagen synthesis in fibroblastic cells . Methods i) RAW264.7 macrophages were divided into solvent-control group and dust-affected group, and then treated with 0 and 120 mg/L ( final concentration ) uranium dust suspension for 0, 2, 4, 8, 16, 24 and 32 hours.The supernatants of cells from these two groups were collected , and transforming growth factor beta 1 ( TGF-β1 ) levels were measured by enzyme-linked immunosorbent assay ( ELISA ) .The best time phase was defined , and t...