[Application of precision-cut lung slice technology to study the role of DDR2 in pulmonary fibrosis].

Pulmonary fibrosis is a severe lung interstitial disease characterized by the destruction of lung tissue structure, excessive activation and proliferation of fibroblasts, secretion and accumulation of a large amount of extracellular matrix (ECM), and impaired lung function. Due to the complexity of the disease, a suitable animal model to mimic human pulmonary fibrosis has not yet been established. Precision-cut lung slice (PCLS) has been a widely used in vitro method to study lung physiology and pathogenesis in recent years. This method is an in vitro culture technology at the level between organs and cells, because it can preserve the lung tissue structure and various types of airway cells in the lung tissue, simulate the in vivo lung environment, and conduct the observation of various interactions between cells and ECM. Therefore, PCLS can compensate for the limitations of other models such as cell culture. In order to explore the role of discoidin domain receptor 2 (DDR2) in pulmonary fibrosis, Ddr2flox/flox mice were successfully constructed. The Cre-LoxP system and PCLS technology were used to verify the deletion or knockdown of DDR2 in mouse PCLS. Transforming growth factor ß1 (TGF-ß1) can induce fibrosis of mouse PCLS in vitro, which can simulate the in vivo environment of pulmonary fibrosis. In the DDR2 knock down-PCLS in vitro model, the expression of various fibrosis-related factors induced by TGF-ß1 was significantly reduced, suggesting that knocking down DDR2 can inhibit the formation of pulmonary fibrosis. The results provide a new perspective for the clinical study of DDR2 as a therapeutic target in pulmonary fibrosis.

Determination of perfluorocarboxylic acids in fish by ultra performance liquid chromatography tandem mass spectrometry / 预防医学

Objective@#To develop the ultra performance liquid chromatography tandem mass spectrometry ( UPLC-MS/MS ) for the determination of perfluorocarboxylic acids ( PFCAs ) in fish.@*Methods@#The fish samples were extracted with tert-butyl methyl ether and purified by WAX columns. The WAX cartridges were rinsed with methanol and 25 mmol/L ammonium acetate, and the target compound residues were eluted with 0.5% ammonia methanol and then redissolved with 50% methanol aqueous solution after nitrogen blowing to nearly dry. Nine kinds of PFCAs were simultaneously quantified by UPLC-MS/MS with 1 mmol/L ammonium acetate-methanol solution as the mobile phase.@*Results@#The extraction was separated well in UPLC BEH C18 column. There were good linear correlations of nine kinds of PFCAs in the range of 1.0-200.0 ng/mL, with the coefficients all more than 0.99. The limits of detection and quantification were 0.06-0.19 μg/kg and 0.19-0.62 μg/kg, respectively. The recovery rates were 70.08%-117.24% at different spiked levels ( 5.0, 25.0, 50.0 μg/kg ), and the relative standard deviations were 2.31%-19.68%. @*Conclusion@#Through optimizing the pretreatment conditions, the mobile phase of liquid chromatography and the detection conditions of mass spectrometry, the UPLC-MS/MS could meet the monitoring requirements of PFCAs in fish.

Simultaneous determination of 20 phthalate esters in oil-free food by UPLC/MS/MS.

A quantitative method was established for the determination of 20 phthalate esters (PAEs) in oil-free food by ultra-performance LC/MS/MS and was used to evaluate the PAEs of 111 oil-free samples from supermarkets in Hangzhou City. By quantification with the internal standard D4-bis(2-ethylexyl) phthalate, linearity ranges of the 20 PAEs were observed with correlation coefficients of 0.9990-0.9999. For liquid and solid sample, the spiking recoveries were 65.5-129.9% with RSD of 2.7-9.7% and 70.9-126.9% with RSD of 1.6-9.8% (n = 6), and the method LODs were 0.05-7.4 microg/L and 0.6-14.4 microg/kg, respectively. Most of the 111 oil-free samples had detectable PAEs; the detection rate was 23.0-42.0%, and the concentration of PAEs was in the range of 1.0-38 610.9 microg/kg. The detection rate in the drink packaged in a glass bottle was the highest, next was laver, and the detection rate in the drink packaged in a plastic bottle was the lowest.

Rapid determination of quinolones in cosmetic products by ultra high performance liquid chromatography with tandem mass spectrometry.

This study developed an improved analytical method for the simultaneous quantification of 13 quinolones in cosmetics by ultra high performance liquid chromatography combined with ESI triple quadrupole MS/MS under the multiple reaction monitoring mode. The analytes were extracted and purified by using an SPE cartridge. The limits of quantification ranged from 0.03 to 3.02 µg/kg. The precision for determining the quinolones was <19.39%. The proposed method was successfully developed for the determination of quinolones in real cosmetic samples.

Disruption of zebrafish (Danio rerio) sexual development after full life-cycle exposure to environmental levels of triadimefon.

In this study, zebrafish was exposed to environmental levels of triadimefon (0.125, 0.25, 0.5 µg/mL) from 24 h post fertilization to 120 days post fertilization. Several endpoints that related to reproductive function were evaluated. It was found that the body length, body weight and vitellogenin transcription were significantly reduced for fish exposed to triadimefon. Histological examination showed that the sex ratio of fish skewed to male and female exposed to 0.5 µg/mL triadimefon had immature ovary. The breeding success, as determined from data on egg production and spawning, was reduced in fish exposed to 0.25 µg/mL triadimefon. In the offspring, the reduced egg fertility, hatching rate and survival were observed in eggs exposed to 0.5 µg/mL triadimefon. These findings indicated that triadimefon had the potential to adversely affect the sexual development and breeding success through the multiple endocrine actions.