BACKGROUND:Studies have found that after stimulation, chemerin can further amplify the inflammatory signal, resulting in the release of inflammatory factors and matrix metaloproteinases. It indicates that chemerin may serve as an important regulator of cartilage metabolism, and plays an important role in the pathogenesis of osteoarthritis. OBJECTIVE: To explore the correlation between level of chemerin in synovia and serum and severity of knee osteoarthritis. METHODS: Eighty patients with knee osteoarthritis were enroled in the study. Knee osteoarthritis grading was evaluated according to the Kelgren-Lawrence classification. Chemerin levels in synovia and serum were examined with enzyme-linked immunosorbent assay. RESULTS AND CONCLUSION:The level of chemerin in synovia and serum in patients with knee osteoarthritis were positively correlated with the Kelgren-Lawrence classification (r=0.981,P< 0.001;r=0.901,P < 0.001). And there was a positive correlation between the level of chemerin in synovia and in serum (r=0.596,P < 0.01). Experimental findings suggest that the levels of chemerin in synovial fluid and serum that are positively correlated with the Kelgren-Lawrence classification can be used as a reference biomarker of severity of knee osteoarthritis.

A thermal desorption ( TD) device was developed and coupled to gas chromatography ( GC) or gas chromatography-mass spectrometry ( GC-MS ) for the qualitative and quantitative analysis of semi-volatile organic compounds on atmospheric particulate matters ( PM ) . The TD was operated by direct heating and placed on the GC injector, leading to high heating rate and easy transfer of analytes to GC without focusing of analytes by cold trap. For establishing the TD-GC method, the materials used for supporting PM samples, temperature and time of thermal desorption, and types of sample injection were investigated for detection of sixteen polycyclic aromatic hydrocarbons ( PAHs) and nine n-alkanes. The limits of detection of the proposed TD-GC method were in the range of 0. 014-0. 093 ng for PAHs, and 0. 016-0. 026 ng for n-alkanes, respectively, with the correlation coefficients of correlation above 0. 9975. The TD-GC method was applied to the determination of trace PAHs and n-alkanes on PM10 samples from three cities. The recoveries were in the range of 95%-135% ( PAHs) and 95%-115% ( n-alkanes) , respectively. Finally, the TD was coupled to GC-MS for comparison of the contents of PAHs and n-alkanes on PMx with different particulate size ( x=10 , 5, 2, 1, 0. 5, 0. 25, 0. 1).