ABSTRACT
@#Objective - （ ） To investigate the effects of nuclear factor erythroid 2 related factor 2 NRF2 on the oxidative stress （ ） Methods ） ，， induced by trichloromethane TCM in human normal hepatocyte L02 cells. i L02 cells were stimulated with 1 2 ， ， ， （ ）， 4 8 12 16 and 20 mmol/L TCM solution dissolved in dimethyl sulfoxide and the control group and blank group were set ， - ， up. After culturing for 24 hours the cell viability was detected by CCK 8 colorimetric method and the concentration of TCM ） -， - stimulation was screened. ii L02 cells in logarithmic growth phase were randomly divided into control group and low medium - ， ， ， and high dose groups. After 24 hours of exposure to 0 4 8 and 12 mmol/L TCM the cells were collected. The activity of （ ）， （ ）， （ - ） （ ） superoxide dismutase SOD catalase CAT glutathione peroxidase GSH Px and the level of malondialdehyde MDA NRF2， - （HO-1）， were detected by colorimetric analysis. The mRNA expression levels of heme oxygenase 1 glutamate cysteine （GCLC） （） （NQO1） - ligase catalytic subunit and NAD P H quinone dehydrogenase 1 were detected by real time fluorescence ， - ， polymerase chain reaction. The protein levels of NRF2 HO 1 GCLC and NQO1 were detected by Western blotting.Results ） ， ， ， ， i When the concentration of TCM was 4 8 12 16 and 20 mmol/L the survival rate of L02 cells decreased （ P ） ， ， significantly compared with the control group all <0.05 . The concentration of 0 4 8 and 12 mmol/L were selected as the ） ， - stimulation doses for subsequent experiments. ii Compared with the control group the activities of SOD and GSH Px in L02 （ P ） （ P ）， - cells in the three doses groups decreased all <0.05 and the levels of MAD increased all <0.05 with a dose effect - （P ）， relationship. The CAT activity of L02 cells in the medium dose group was lower than that in the control group <0.05 and the - （ P ） CAT activity of L02 cells in the high dose group was lower than that in the others three groups all <0.05 . Compared with the ， NRF2 - （P ），NRF2 control group the relative expression levels of mRNA in L02 cells in the low dose group decreased <0.05 - （P ）， NRF2 mRNA in L02 cells in the medium dose group increased <0.05 mRNA and NRF2 protein expression in L02 cells in （ P ） HO-1，GCLC， NQO1 ， the highdose group increased both <0.05 . The relative expression level of mRNA and GCLC NQO1 （ P ） protein expression in L02 cells in the three doses groups increased compared with the control group all <0.05 . The relative NRF2 - - - expression level of mRNA in L02 cells in the high dose group was higher than that in the low and medium dose groups （ P ）， - （P ）， both <0.05 and the relative expression of NRF2 protein was higher than that in the low dose group <0.05 but the HO-1 GCLC - - （ relative expression levels of and mRNA and HO 1 protein level were lower than those in the medium dose group all P ）Conclusion - <0.05 . TCM exposure can inhibit the proliferation of L02 cells by inducing oxidative stress with a dose effect ， relationship. In this process the antioxidant mechanism mediated by NRF2 was activated. The expression of antioxidant defense ， - ， and detoxification related target genes downstream of NRF2 signaling pathway was activated and the expression of HO 1 - GCLC and NQO1 was up regulated to alleviate the oxidative damage caused by TCM.
ABSTRACT
OBJECTIVE: To establish a method for detecting dichloromethane,trichloromethane and 1,2-dichloroethane in blood by gas chromatography-mass spectrometry. METHODS: Using static headspace analysis, three halogenated hydrocarbons in blood samples were separated by DB-5 MS elastic capillary column and detected by gas chromatographymass spectrometry. RESULTS: There was a good linear relationship in the selected range of dichloromethane,trichloromethane and 1,2-dichloroethane in blood. The linear correlation coefficient was greater than 0. 999 8. The detection limit and the lower limit of quantitation was 0. 19-0. 28 and 0. 64-0. 93 μg/L,respectively. The average recovery rate was 95. 1%-106. 6%. The within-run and between-run relative standard deviation was 2. 9%-4. 9% and 5. 0%-7. 0%,respectively. The samples could be preserved at room temperature or 4 ℃ for 3 days and at-8 ℃ or below for7 days. CONCLUSION: With the features of high sensitivity,precision,accuracy,easy operation and less interference,this method is suitable for detecting dichloromethane,trichloromethane and 1,2-dichloroethane in the blood.
ABSTRACT
We report 2 cases of hepatotoxicity in cleanroom workers due to high retained chloroform air concentrations. The women, aged 34 and 41 years, who had been working in a medical endoscopic device manufacturer as cleanroom workers for approximately 40-45 days suffered severe liver damage. Two measured time-weighted averages of the chloroform concentration in the air in the cleanroom were 82.74 and 64.24 ppm, which are more than 6 times the legal occupational exposure limit in Korea. Only 7% of the cleanroom air was newly introduced from outside. The clinical courses of these cases and workplace inspection, led us to conclude that both cases of hepatotoxicity were caused by chloroform exposure.