1. Immune cytotoxicity of trichloroethylene and its mechanism in activated human T cells
Jie WU ; Hailan WANG ; Qifeng WU ; Xiangrong SONG ; Hongling LI ; Na ZHAO
China Occupational Medicine 2017;44(01):1-13
OBJECTIVE: To explore the immune cytotoxicity effect and its mechanism of trichloroethylene( TCE) on activated human T cells. METHODS: a) Different concentrations of TCE( 0. 32,0. 63,1. 25,2. 50,5. 00,10. 00 mmol / L)were used to treat activated T cells [activated with cluster of differentiation( CD) 3 and CD28] respectively. Dimethyl sulfoxide( DMSO) was used in the solvent group and the control group used no TCE or DMSO. The survival rate of activated T cells was calculated using CCK-8 assay after being cultured for 24 hours. b) Different concentrations of TCE( 0. 00,2. 50,5. 00 mmol/L) were used to treat activated T cells. The apoptosis of cells was detected using flow cytometry. c) Different concentrations of TCE( 0. 00,0. 32,0. 63,1. 25,2. 50,5. 00 mmol / L) were used to treat activated T cells and the level of cytokines as interleukin( IL)-2 and IL-6 in cell culture supernatant was detected using enzyme linked immunosorbent assay after culturing for 24 hours. d) The control group and TCE treatment group of activated T cells were treated with 0. 00 and 5. 00 mmol / L TCE respectively. Cells were collected after culturing 0,30,60 and 120 minutes. Western Blot was used to detect the protein expression of signal transducers and activators of transcription3( STAT3) and phospho-STAT3( p-STAT3). RESULTS: a) After 24-hour-exposure to TCE,the activated T cell survival rate of 10. 00 mmol / L TCE treatment group were significantly lower than that in the control group and DMSO group( P <0. 05). b) There were no significant differences in cell apoptosis of activated T cells after treatment with 0. 00,2. 50 and5. 00 mmol / L TCE( P > 0. 05). c) In groups treated with different concentrations of TCE( 0. 32,0. 63,1. 25,2. 50,5. 00 mmol / L),the level of IL-2 and IL-6 in the cell culture supernatant of activated T cells were significantly higher than that in the control group( P < 0. 05). With the increasing of TCE exposure doses,the levels of IL-2 and IL-6 significantly increased( P < 0. 01) with dose-effect relationship. Compared with the control group,the levels of IL-17 A,interferongamma and transforming growth factor-beta in cell culture supernatant of activated T cells of the TCE treatment groups were no significant differences( P > 0. 05). d) The expression of p-STAT3 protein was low in the control group at different times. The expression of p-STAT3 protein in TCE treatment group was low at 0 minute,but increased at 30,60,120 minutes. The expression of p-STAT3 protein in TCE treatment group was higher than that in the control group at different time points. The levels of STAT3 total protein in TCE treatment group and the control group were similar at different time points,and were higher than the p-STAT3 proteins. CONCLUSION: TCE at 5. 00 mmol / L had no observed toxic effect on activated T cells. High doses of TCE( ≥10. 00 mmol / L) showed cytotoxic damages to activated T cells,and low doses of TCE( ≤5. 00 mmol / L) could stimulate activated T cells to secrete IL-2 and IL-6. Treatment of TCE at 5. 00 mmol / L on activated T cells could up-regulated the level of p-STAT3.
2. The changes of ROR-γt,IL-17A and Foxp3 mRNA expression and promoter methylation in TDI-induced mouse asthma
Xiaoqun WANG ; Qiang JIA ; Zhenling ZHANG ; Gongchang YU ; Yu ZHANG ; Cunxiang BO ; Zhifeng YANG ; Hua SHAO
China Occupational Medicine 2017;44(01):7-13
OBJECTIVE: To explore the changes of retinoic acid related orphan receptor-γt( ROR-γt),interleukin( IL)-17 A and forkhead / winged helix protein 3( Foxp3) mRNA expression and promoter methylation in the process of asthma induced by toluene-diisocyanate( TDI). METHODS: Specific pathogens free grade healthy male BALB / c mice were randomly assigned into asthma group and control group with 18 animals in each group. In the asthma group,the mice were sensitized with 0. 30% TDI( mass-volume concentration) dropped on the dorsum of both ears( 20 μL / ear) on day 1 and day 8. On day 15,the mice were challenged with 20 μL 0. 01% TDI( mass-volume concentration) by the trachea. The control group mice were sensitized and challenged by the same procedures with the same amount of solvent( acetone / olive oil). The mice were challenged 24 hours,the pathological changes of trachea and lung tissues were observed. The bronchoalveolar lavage fluid( BALF) from each group was collected,and the inflammatory cells in BALF were counted and classified. IL-4and Interferon-γ( IFN-γ) levels in BALF supernatant were measured by enzyme-linked immunosorbent assay. ROR-γt,IL-17 A and Foxp3 mRNA expression in the lung tissue were measured by real-time fluorescent quantitative polymease chain reaction. The degree of ROR-γt,IL-17 A and Foxp3 promoter methylation in lung issue were detected by Mass Array system.RESULTS: The asthmatic group demonstrated the symptoms of acute asthma,such as breathing deeply and fastly,bowing the back,lifting the forelimbs,et al. But the control group had no such symptoms in mice. Hematoxylin-Eosin staining showed obvious inflammatory lesions in the trachea and lung tissue of asthmatic mice. Compared with the control group,the white blood cell count,the neutrophil and eosinophil percentages in BALF,the IL-4,IFN-γ levels in BALF supernatant in asthma group were all significantly increased( P < 0. 01),meanwhile the lymphocyte and monocyte percentages in BALF were reduced( P < 0. 01); ROR-γt mRNA expression was significantly increased( P < 0. 01),and the degree of promoter methylation from sites 3,4,5,6,8,11 and 12 was significantly reduced( P < 0. 05); IL-17 A mRNA expression was significantly increased( P < 0. 01),and the degree of promoter methylation from sites 6 and 7 was significantly reduced( P < 0. 01); Foxp3 mRNA expression was significantly reduced( P < 0. 01),and the degree of promoter methylation from sites 1 and 10 was significantly increased( P < 0. 01). CONCLUSION: Th17 / Treg cell immune imbalance occurs in asthma induced by TDI. ROR-γt,IL-17 A and Foxp3 gene promoter methylation abnormalities may be involved in Th17 / Treg cell immune imbalance.
3. Mechanism of coke oven emissions-induced acute toxicity in HL-60 cells
Meili SHEN ; Qiuyan XIE ; Hongli LI ; Yanhua WANG ; Qianpeng JI ; Qingrong WANG ; Yufei DAI ; Huawei DUAN
China Occupational Medicine 2017;44(01):14-19
OBJECTIVE: To establish the cell model using human leukemia cell line HL-60 for exposure of coke oven emissions( COE) in vitro and to explore the mechanism of COE-induced acute toxicity in HL-60 cells. METHODS: HL-60 cells were collected in their logarithmic growth phase and cultured in medium that had final concentrations of COE in 2. 5,5. 0,10. 0 and 20. 0 mg / L for 24 hours. Cell survival rate was examined by CCK-8 assay. The cytotoxicity was evaluated using lactate dehydrogenase release assay. Reactive oxygen species( ROS) production was determined by the 2',7'-dichlorofluorescein diacetate and nitroblue tetrazolium method. The activation of nuclear factor-κB( NF-κB) pathway was evaluated by western blot. RESULTS: With the increasing exposure concentrations of COE,the cytotoxicity of HL-60 cells increased( P < 0. 01),the cell survival rate decreased( P < 0. 01),intracellular ROS decreased( P < 0. 01),whereas extracellular ROS increased( P < 0. 01). These changes had a dose-effect relationship. The levels of phospho-nuclear factor-kappa B p65 and phospho-inhibitor of kappa Bα were higher in all the COE-treated cells compared with untreated cells( P < 0. 05),with no dose-effect relationship. CONCLUSION: COE could cause acute toxicity in HL-60 cells in a doseeffect relationship. The mechanism may be related to the COE-induced in-balanced ROS release and removal,leading to the activation of NF-κB pathway. HL-60 cells can be used as a common cell line for COE hematotoxicity analysis.
4. Comparative toxic effect of different aluminum compounds in PC12 cells
Chunmei DUAN ; Jin FAN ; Chengyun LIU ; Ling ZHANG ; Qiao NIU
China Occupational Medicine 2017;44(01):20-24
OBJECTIVE: To investigate the toxic effects of four different kinds of aluminum compounds in rat adrenal-derived pheochromocytoma cell PC12. METHODS: PC12 cells at logarithmic growth phase were treated with four different kinds of aluminum compounds: aluminum maltolate( concentration was 0. 0,0. 1,0. 2,0. 4,0. 8 mmol / L),aluminum chloride( concentration was 0. 0,1. 0,2. 0,4. 0,8. 0 mmol/L),aluminum citrate( concentration was 0. 0,1. 0,2. 0,4. 0,8. 0mmol / L) and aluminum lactate( concentration was 0. 0,2. 0,4. 0,8. 0,16. 0 mmol / L) for 24 hours,respectively. The cell viability was determined with CCK-8 assay,and the apoptotic rate was detected by flow cytometry. RESULTS: All of the aluminum compounds suppressed the cell viability and increased apoptosis( P < 0. 01). Most of the effects were in a dose dependent manner. Comparing with the control,the minimum effective concentration of aluminum maltolate,aluminium chloride,aluminum citrate and aluminum lactate were 0. 2,2. 0,2. 0 and 4. 0 mmol / L,respectively,in cell viability( P < 0. 05); and 0. 1,2. 0,1. 0 and 2. 0 mmol/L in cell apoptosis( P < 0. 05). The 24 hours 50% inhibitory concentration of the above four aluminum compounds were( 0. 45 ± 0. 01),( 4. 02 ± 0. 39),( 5. 37 ± 0. 88) and( 6. 31 ±0. 58) mmol / L,respectively. CONCLUSION: Treatment of all four aluminum compounds had reduced cell viability and increased the percentage of cell apoptosis in a dose-dependent manner in PC12 cells. The best dose-response relation was observed in aluminum maltolate treatment group,and a relatively low dose of it was required in in-vitro toxicology study.Therefore,aluminum maltolate posed to be better reagent than the other three for in-vitro aluminum toxicity study.
5. Intervention effect and mechanism of polyguanylic acid on pulmonary fibrosis in silica-exposed rats
Meng YANG ; Na WANG ; Sanqiao YAO
China Occupational Medicine 2017;44(01):25-30
OBJECTIVE: To observe the intervention effect of polyguanylic acid( Poly G) on silicosis fibrosis in rats and to explore its possible mechanism. METHODS: Specific pathogen free adult male SD rats were randomly divided into 6 groups:control group,silicosis model group and 4 intervention groups( intervention group 1,2,3 and 4),with 5 rats in each group. Except for the control group,the other 5 groups were treated with 1. 0 m L silica suspension( 50. 0 g / L mass concentration) by intratracheal intubation,four intervention group was given by intraperitoneal injection of 1,2,3 and 4doses of Poly G at 2. 5 mg / kg body weight after establishing the model for 1 to 21 days. All rats were sacrificed 28 days after silicosis model establishment. Lung pathological changes were observed and the pulmonary fibrosis was evaluated by Ashcroft scores. The expression of Macrophage receptor with collagenous structure( MARCO),transforming growth factor-β1( TGF-β1),E-cadherin,Vimentin and α-smooth muscle actin( α-SMA) protein were detected by western blot.RESULTS: In the model group,a large number of dust cell aggregates were found in the alveolar cavity and diffuse collagen deposition appeared in the pulmonary interstitial,indicating that silicosis model was successfully constructed. The alveolar structure of the single dose intervention group was integral and the degree of fibrosis was significantly less than that of the silicosis model group. Compared with the control group,MARCO,TGF-β1,Vimentin and α-SMA expression levels of silicosis model group were increased,the expression level of E-cadherin decreased, the difference was statistically significant( P < 0. 05). Compared with the silicosis model group,TGF-β1,Vimentin and α-SMA expression levels of single dose intervention group decreased,E-cadherin expression level increased,the difference was statistically significant( P < 0. 05). The dose-response relationship could not perceived between the Poly G intervention times and the Ashcroft scores or the protein expression levels of MARCO,TGF-β1,E-cadherin,Vimentin and α-SMA respectively. CONCLUSION: Poly G can effectively reduce lung inflammation and fibrosis in rats. The effect of single dose intervention( 2. 5 mg / kg body weight,intraperitoneal injection) at the first day after silica exposure is the best. The mechanism of action may be related to the low-does Ply G which can inhibit the epithelial-mesenchymal transition and then result in the decrease of collagen synthesis.
6. Effects of sub-chronic aluminum-maltolate complex exposure on mitochondrial fission and fusion of hippocampus in SD rats
Xueying FU ; Ling YANG ; Wubin WANG ; Qiao NIU ; Jisheng NIE
China Occupational Medicine 2017;44(01):31-35
OBJECTIVE: To study effects and mechanism of sub-chronic aluminum-maltolate complex [Al( mal)3]exposure on mitochondrial damage of hippocampus in rats. METHODS: Sixty specific pathogen free healthy adult male SD rats were randomly divided into 5 groups: a blank group,a control group,a low-,a medium- and a high-dose group,with 12 rats in each group. Blank group was not treated. Low-,medium- and high-dose groups were treated with 0. 41,0. 81,1. 62 mg / kg body weigh of Al( mal)3solution respectively. The control group was treated with an equal volume of saline. Al( mal)3exposure was conducted by intraperitoneal injection every other day for 90 days. The activities of Na+-K+-ATPase and Ca2 +-Mg2 +-ATPase in hippocampus were tested by chemical colorimetric technique. Western blot analysis was used to detect the relative expression of cytochrome oxidase Ⅳ( Cox Ⅳ),dynamin-related protein 1( Drp1),optic Atrophy 1( Opa1),mitofusin( Mfn) 1,and Mfn2 in hippocampus. RESULTS: The activity of Na+-k+-ATPase in high-dose group was significantly lower than those in blank-,control-,and low-dose groups( P < 0. 05). The activity of Ca2 +-Mg2 +-ATPase in medium-dose group was significantly lower than those in blank group( P < 0. 05),and that in high-dose group was significantly lower than those in the other four groups( P < 0. 05). The relative expression levels of CoxⅣ in mediumand high-dose groups were lower than those of the other three groups( P < 0. 05). The relative expression levels of Drp1 and Mfn2 in medium-and high-dose groups were significantly higher than those in blank-,control and low dose group( P <0. 05). The relative expression levels of Opa1 in medium- and high-dose groups were significantly higher than those in blank-,control- and low-dose groups( P < 0. 05). The relative expression levels of Mfn1 in medium- and high-groups were significantly higher than that in blank group( P < 0. 05). CONCLUSION: The mitochondria of rat hippocampus was damaged by the sub-chronic aluminum-maltolate exposure. The damage may be related to the change of mitochondrial dynamics.
7. Effect of silencing of poly(ADP-ribose) polymerase-1 on cell apoptosis induced by hydroquinone in rat bone marrow mesenchymal stem cells
Yuting GAO ; Jinlin DU ; Hui YANG ; Huanwen TANG
China Occupational Medicine 2017;44(01):36-41
OBJECTIVE: To explore the effect of silencing of poly( ADP-ribose) polymerase-1( PARP-1) on cell apoptosis induced by hydroquinone( HQ) in rat bone marrow-derived mesenchymal stem cells( BMMSCs). METHODS: i) The RNA expression vectors for PARP-1 gene were transfected into BMMSCs. Neomycin was used to select the transfected cells that stably expressed PARP-1-shRNA. Western blotting was used to examine the gene silencing efficiency. ii) BMMSCs with PARP-1 silencing were sorted as the treated group,while BMMSCs with empty vector were considered as the control group.HQ dissolved in phosphate buffer solution at the concentrations of 0. 0,2. 5,5. 0,10. 0,20. 0,40. 0,80. 0,160. 0 and320. 0 μmol / L were given to both groups for 24 hours. The cell viability was detected by methyl thiazolyl tetrazolium assay,and the concentration of HQ was chosen for the following study based on cell viability. iii) Both groups were treated by HQ at concentrations of 0. 0-20. 0 μmol / L for 24 hours,then the apoptosis of BMMSCs was detected by flow cytometry. The PARP-1 mRNA expression was determined by real-time fluorescent quantitative polymerase chain reaction assay. RESULTS: i) PARP-1 silencing cells and empty vector control cells were successfully screened with a mass concentration of 400 mg / L neomycin,and confirmed by level of protein expression. The interference efficiency of PARP-1 gene and inhibition efficiency was 85. 00%. ii) Based on the result of cell viability,HQ at concentrations of 0. 0-20. 0 μmol / L was chosen for the following study. iii) Compared with the group treated by HQ at concentration of 0. 0 μmol / L,the rate of early apoptosis of control group increased significantly with HQ at concentration of 10. 0 μmol / L while that of treated group was increased significantly at concentration of 5. 0 μmol / L( P < 0. 05). In addition,at concentrations of 0. 0-10. 0 μmol / L,the rates of early apoptosis in both groups increased in a dose-dependent manner( P < 0. 01). Compared with the group treated by HQ at concentrations of 0. 0 μmol / L,the expression of PARP-1 mRNA of both groups increased significantly at the concentration of 5. 0 μmol / L( P < 0. 05). The expression of PARP-1 mRNA of treated group was less than that of control group with HQ at every concentration( P < 0. 05). At concentrations of 0. 0-20. 0 μmol / L,the expression of PARP-1 mRNA of both groups increased in a dose-dependent manner( P < 0. 01). CONCLUSION: Silencing PARP-1 in BMMSCs caused cell apoptosis. PARP-1 may participate in cell apoptosis induced by HQ.
8. Research on the inflammatory injury induced by N,N-dimethylformamide in H9c2 cardiomyocytes
Qingxiu RONG ; Yongjian YANG ; Wanwan ZHANG ; Xiaoli MA ; Mei XIANG ; Lulu WANG ; Wenjing SUN
China Occupational Medicine 2017;44(01):42-54
OBJECTIVE: To explore the effect of N,N-dimethylformamide( DMF)-induced inflammatory injury in H9c2 cardiomyocytes and its mechanism. METHODS: H9c2 cardiomyocytes were cultured in vitro and randomly divided into 4different groups: control group,50 mmol / L-group,100 mmol / L-group,200 mmol / L-group. These 4 groups of cells were treated with different DMF concentrations( 0,50,100,200 mmol / L) for 12 hours. The cells were also divided into 6groups and treated with 200 mmol / L DMF at different time points( 0,2,4,6,8,12 h) : control group,2 h-group,4 hgroup,6 h-group,8 h-group and 12 h-group. The level of lactate dehydrogenase( LDH) was detected by colorimetry. The levels of creatine kinase( CK) and isoenzyme of creatine kinase( CK-MB) were detected by ultraviolet spectrometry. The levels of tumor necrosis factor-α( TNF-α),interleukin( IL)-1β,IL-6,and IL-8 were detected by enzyme linked immunosorbent assay. The level of reactive oxygen species( ROS) was detected by fluorescence probe. The location of nuclear factor-kappa B( NF-κB) p65 protein was detected by immunofluorescence cytochemistry( IFC) staining. RESULTS: The levels of LDH,CK and CK-MB in the 50 mmol / L-group,100 mmol / L-group and 200 mmol / L-group were higher than that of the control group( P < 0. 05) and showed a significant dose-effect( P < 0. 05). The levels of LDH,CK and CK-MB in the 6 h-group,8 h-group and 12 h-group were higher than that of the control group( P < 0. 01) and showed a significant time-effect( P < 0. 01). The levels of TNF-α,IL-1β,IL-6 and IL-8 of the 200 mmol / L-group were higher than the control group( P < 0. 05). Compared with the control group,the levels of TNF-α of the 4 h-group,12 h-group were higher( P < 0. 05),the levels of IL-1β of the 2 h-group,4 h-group,6 h-group,8 h-group and 12 h-group were higher( P < 0. 05),the levels of IL-6 of the 2 h-group and 4 h-group were higher( P < 0. 05),the level of IL-8 of the 2 h-group was higher( P < 0. 05). In addition,the levels of TNF-α,IL-1β and IL-6 reached a peak at 4 h-group and the level of IL-8 reached a peak at 2 h-group. The ROS levels of the 2 h-group,4 h-group and 6 h-group were higher than the control group( P < 0. 01),and the level of ROS reached a peak at 2 h-group. Furthermore,IFC staining showed that the fluorescence intensity of NF-κB p65 protein in nucleus of the 2h-group and 4 h-group increased after treatment with DMF,comparing with the control group. CONCLUSION: DMF leads to inflammatory injury in H9c2 cardiomyocytes. ROS and NF-κB might be involved in the process.
9. Sub-chronic oral toxicity of 1,1-diamino-2,2-dinitroethene in rats
Qing LU ; Panhong ZHANG ; Junhong GAO ; Zhiyong LIU ; Hong WANG ; Hong YUE ; Yongchao GAO
China Occupational Medicine 2017;44(01):48-54
OBJECTIVE: To explore the sub-chronic oral toxicity of 1,1-diamino-2,2-dinitroethene( FOX-7) in rats.METHODS: Ninety-six specific pathogen free healthy adult SD rats were randomly divided into control group,low-,medium-,and high-dose groups. Each group consisted of 24 rats,half of them were males and the other half were females.The low-,medium-,and high-dose groups of rats were exposed to 10,30,90 mg /( kg·d) body weigh of 1,1-diamino-2,2-dinitroethene by gavage for 90 days,once a day,6 days a week. The control group was given the same volume of 4%water starch solution. The toxic symptoms,the body weight,food utilization,routine blood,blood biochemical indicators,organ coefficients and histopathology changes of the rats were observed or tested. RESULTS: a) The body weights of male and female rats in the high-dose group in the 28 th day after exposure were lower than those of the control group for the same time and same sex( P < 0. 05). Food utilization in the male and female high-dose group in the 77 th and 90 th day after exposure were lower than those of the control group for the same time and same sex( P < 0. 05). b) Red blood cell counts,hemoglobin levels,hematocrit levels in the female rats of low-,medium-,and high-dose groups were lower than those of the female control group( P < 0. 05). Platelet counts in the female high-dose group was lower than that of the female control group( P < 0. 05). Red blood cell counts,hemoglobin level,hematocrit level and mean corpuscular hemoglobin concentration in the male high-dose group were lower than those of the male control group( P < 0. 05). The platelet counts in the male medium-,and high-dose group were lower than that of the male control group( P < 0. 05). c) Total cholesterol levels in female medium-,and high-dose group and blood urea nitrogen level in the female high-dose group were higher than those of the female control group( P < 0. 05). In high-dose group,the levels of total protein and uric acid were higher and lactate dehydrogenase level was lower than those of the control group( P < 0. 05). d) The spleen organ coefficients in the female high-dose group were higher and those in male medium- and high-dose groups were higher than those of the control group for same sex( P < 0. 05). The organ coefficients of liver and kidney in high-dose group were higher than those of the control group( P < 0. 05),the organ coefficients of testis and epididym in the male high-dose group were lower than those of the male control group( P < 0. 05). The testis convoluted tubule shrink and seminiferous cells decreased in the male high-dose group. e) The no observed adverse effect level of FOX-7 dinitroethene in female rats were less than10. 00 mg /( kg·d) and it was 10. 00 mg /( kg·d) in the male rats. CONCLUSION: FOX-7 could inhibit the growth of rats and damage the blood system and male reproductive system.
10. Comparative study on the diagnostic criteria of occupational noise-induced deafness between version 2014 and version 2007
Jing ZHANG ; Aichu YANG ; Qianling ZHENG ; Xiaoyang LIANG ; Weixin HUANG ; Jijun GUO
China Occupational Medicine 2017;44(01):55-59
OBJECTIVE: To analyze the impact of GBZ 49-2014 Diagnosis of Occupational Noise-induced Deafness and GBZ49-2007 Diagnostic Criteria of Occupational Noise-induced Deafness on the diagnosis of occupational noise-induced deafness( ONID). METHODS: A total of 84 individuals,who were workers exposed to noise and diagnosed as observation subjects by GBZ 49-2007 were selected as the subjects of study by judgment sampling. They were diagnosed based on the criteria of GBZ 49-2014 and GBZ 49-2007. The impact of different diagnostic audiometry,different age and gender correction methods and the inclusion of a weighting of 0. 1 high-frequency 4. 0 k Hz hearing threshold of GBZ 49-2014 on the diagnosis of ONID was analyzed. RESULTS: The binaural high frequency threshold average( BHFTA) calculated by GBZ 49-2014 were lower than that of GBZ 49-2007 [( 52. 1 ± 10. 3) vs( 52. 8 ± 10. 1) d B,P < 0. 05 ],but monaural threshold of weighted value( MTWV) of the good ear calculated by GBZ 49-2014 were higher than speech frequency threshold average( SPTA) of the good ear of GBZ 49-2007 [( 23. 2 ± 4. 1) vs( 19. 3 ± 4. 8) d B,P < 0. 01]. All of the 84 patients had BHFTA ≥40 d B and SPTA < 26 d B when diagnosed by GBZ 49-2007,and could not be diagnosed as ONID. A total of33. 3% patients had BHFTA ≥40 d B and MTWV ≥26 d B when diagnosed by GBZ 49-2014 which could be diagnosed as mild ONID. The detection rate of ONID was 21. 4% to 34. 5%( P < 0. 01) when the threshold of 4. 0 k Hz was used as the weighting diagnostic threshold of hearing in the case of using different diagnostic audiograms and different age and sex correction methods. CONCLUSION: A high-frequency hearing threshold of 4. 0 k Hz with a weighting of 0. 1 was included in GBZ 49-2014 as a diagnostic threshold,which reduced the diagnostic threshold of ONID.