Effect of oral exposure to trichloroethylene on JMJD3 expression and polarization of M1 Kupffer cells / 环境与职业医学

Background Trichloroethylene (TCE) can enter human body through biological accumulation of polluted water or air, resulting in health hazards. The most commonly involved organs are the liver. Objective To observe potential polarization of M1 Kupffer cells (KCs) in mice liver exposed to TCE orally, and to investigate the relationship between histones lysin demethylase JMJD3 and M1 KCs polarization. Methods A total of 72 SPF BALB/c mice aged 6 to 8 weeks were randomly divided into a blank control group (n=18), a vehicle control group (n=18), a 2.5 mg·mL−1 TCE group (n=18), and a 5.0 mg·mL−1 TCE group (n=18) after adaptive feed for one week. A TCE transoral exposure model was established after eight weeks of administration according to previous research of the research group. In the 2nd, 4th, and 8th weeks, the mice were sacrificed and liver tissue samples were collected. Western blotting was used to detect the expression level of JMJD3 in the liver tissue samples. Immunofluorescence was used to co-locate the macrophage marker F4/80 and the surface marker CD11c of M1 macrophages. Immunohistochemistry was used to detect the expressions of CD16/32, a marker of M1 macrophages, and TNF-α, an inflammatory factor of M1 macrophages in mouse liver. Results In the 2nd, 4th, and 8th weeks, the mice in each group were generally in good condition, and no individual died due to TCE. There was no statistically significant difference in the amount of water consumed by each group, nor in the body weight gain and the liver coefficient of mice at each time point (P>0.05). The results of Western blotting analysis showed that there was no statistically significant difference in JMJD3 protein expression level between the blank control group and the vehicle control group at each time point, the expression levels of JMJD3 protein in the 2.5 mg·mL−1 TCE group and the 5.0 mg·mL−1 TCE group were higher than that in the control group , and the expression level of JMJD3 protein in the 5.0 mg·mL−1 TCE group was higher than that in the 2.5 mg·mL−1 TCE group (P<0.05). The results of immunofluorescence co-localization showed that the expressions of F4/80 and CD11c were low in the blank control group and the vehicle control group, while the expressions of F4/80 and CD11c were increased in the 2.5 mg·mL−1 and the 5.0 mg·mL−1 TCE groups. The results of immunohistochemistry showed that the expressions of CD16/32 and TNF-α in the blank control group and the vehicle control group were low, and there were large deposits in the 2.5 mg·mL−1 TCE group and the 5.0 mg·mL−1 TCE group. Conclusion The polarization of M1 KCs and the expression of proinflammatory factors may be related to an increased expression level of JMJD3 induced by oral TCE exposure.

The role of TNF-α/TNFR1 inhibiting autophagy of M1-type Kupffer cells in liver injury in trichloroethylene-sensitized mice / 中华劳动卫生职业病杂志

Objective: To detect the expression levels of M1-type polarization and autophagy-related indicators in the liver of trichloroethylene (TCE) -sensitized mice, and to explore the role of liver tumor necrosis factor-α (TNF-α) and tumor necrosis factor receptor 1 (TNFR1) in regulating M1-type Kupffer cells autophagy in liver injury in TCE-sensitized mice. Methods: In November 2019, according to simple random grouping, 45 SPF grade BALB/c female mice (6-8 weeks old) were divided into 4 groups: blank control group (n=5) , solvent control group (n=5) , TCE treatment group (n=18) , TCE+R7050 (inhibitor) treatment group (n=17) . Transdermally sensitized mice, 24 h after the last challenge, the mice were divided into TCE sensitized group and TCE non-sensitized group according to the skin reaction score. The livers of mice were harvested, and the pathological changes of the livers were observed under light and electron microscopes. Western blotting was used to detect the expressions of TNF-α, TNFR1 and autophagy-related indexes. The expression of inducible nitric oxide synthase (iNOS) , a marker of M1-type Kupffer cells, was detected by immunohistochemistry, and the occurrence of autophagy in M1-type Kupffer cells was detected by immunofluorescence double-labeling method. Results: The sensitization rate of TCE treatment group was 38.9% (7/18) , and TCE+R7050 treatment group was 35.3% (6/17) , with no significant difference between the two groups (P=1.000) . Compared with the blank control group, mice in the TCE sensitized group had abnormal liver ocytes, obvious liver injury, reduced mitochondria and broken endoplasmic reticulum. Western blotting results showed that the expressions of TNF-α and TNFR1 protein in the liver of the mice in the TCE sensitized group increased, the expression of iNOS protein in M1-type Kupffer cells increased, and the expressions of autophagic microtubule-associated protein 1 light-chain 3 (LC3B) and Beclin1 protein were decreased (P<0.05) . The results of immunohistochemistry showed that iNOS was not significantly expressed in the blank control group and solvent control group, and a small amount of expression was found in the TCE non-sensitized group, the positive staining area was obvious in TCE sensitized group, and the expression of iNOS was significantly increased (P<0.05) . Immunofluorescence results showed that the iNOS protein levels in the blank control group, solvent control group and TCE non-sensitized group were lower, and only partially colocalized with P62; the colocalization of iNOS with P62 in the TCE sensitized group was significantly increased. Conclusion: TNF-α/TNFR1 signaling pathway may promote liver injury in TCE-sensitized mice by inhibiting autophagy of M1-type Kupffer cells.

The role of ROS/TXNIP/NLRP3 pathway in the skin injury of trichloroethylene sensitized mice / 中华劳动卫生职业病杂志

Objective: To explore the mechanism of reactive oxygen species/thioredoxin-interacting protein/nucleotide-binding oligomerization domain-like receptor 3 (ROS/TXNIP/NLRP3) pathway in the skin injury of trichloroethylene (TCE) sensitized mice. Methods: In August 2020, 40 female BALB/c mice were randomly divided into control group (n=5) , solvent control group (n=5) , TCE treatment group (n=15) and TCE+(2-(2, 2, 6, 6-Tetrameyhylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl) triphenylphosphonium chloride (Mito TEMPO) treatment group (n=15) . The TCE sensitization model was established. Mice in the TCE treatment group and TCE+Mito TEMPO treatment group were divided into the sensitized positive group and the sensitized negative group according to the skin erythema and edema reactions on the back of the mice 24 h after the last stimulation. The mice were sacrificed 72 h after the last stimulation, the back skin of the mice was taken, and the skin lesions were observed. Immunohistochemistry (IHC) was used to detect the expression level of NLRP3, and the Western Blot was performed to detect the expression levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC) , cysteinyl aspartate specific proteinase 1 (Caspase 1) , Interleukin-1β (IL-1β) and TXNIP proteins in the skin of the mice, the reactive oxygen species (ROS) kit was used to detect the level of intracellular ROS in the back skin tissue. Results: The sensitization rates of TCE treatment group and TCE+Mito TEMPO treatment group were 40.0% (6/15) and 33.3% (5/15) , respectively, and there was no significant difference between the two groups (P>0.05) . The back skin of the mice in the TCE sensitized positive group was thickened and infiltrated by a large number of inflammatory cells. The number of mitochondria in the epidermis cells was significantly reduced, the mitochondrial crest disappeared and vacuolar degeneration occurred. TCE+Mito TEMPO sensitized positive group had less damage, more mitochondria and relatively normal cell structure. Compared with the solvent control group and corresponding sensitized negative groups, the expression levels of NLRP3, ASC, Caspase 1, IL-1β, TXNIP proteins and the content of ROS in the TCE sensitized positive group and TCE+Mito TEMPO sensitized positive group were significantly increased (P<0.05) . Compared with TCE sensitized positive group, the expression levels of NLRP3, ASC, Caspase 1, IL-1β, TXNIP proteins and the content of ROS in the TCE+Mito TEMPO sensitized positive group were significantly decreased (P<0.05) . Conclusion: ROS/TXNIP/NLRP3 pathway was activated and then encouraged the release of IL-1β, finally aggravated the TCE-induced skin injury.

Role of oxidative stress in trichloroethylene-induced toxicity / 环境与职业医学

Trichloroethylene (TCE) is a common industrial organic solvent and environmental contaminant. People are exposed to TCE through occupational contact or environmental pollution, which leads to serious human health hazards. A large number of studies have shown that oxidative stress plays an important role in the TCE-induced multi-target organ toxicity. However, the research of related signaling pathways remains to be deepened. In this review, we summarized the epidemiological, animal, and cellular studies correlated to liver toxicity, kidney toxicity, cardiac developmental toxicity, placental developmental toxicity, neurodevelopmental toxicity, and autoimmune response induced by TCE. In addition, the possible molecular mechanisms of oxidative stress in TCE-induced toxicity were concluded, including DNA damage, mitochondrial dysfunction, cell apoptosis, and abnormal activation of the immune system. Through literature review, we proposed that nuclear factor E2 related factor 2 may play an important role in mediating TCE-induced target organ toxicity, providing a theoretical basis for the prevention and treatment of adverse health effects caused by TCE.

Analysis on dynamic change of cytokines in patients with occupational trichloroethylene-induced medicamentosa-like dermatitis / 中国职业医学

OBJECTIVE: To analysis the dynamic change of cytokines in patients with occupational trichloroethylene-induced medicamentosa-like dermatitis(OMDT) at the initial stage of treatment. METHODS: Twenty-two cases of early onset OMDT with no glucocorticoid treatment history were selected as the research subjects by judgment sampling method. Blood samples were collected on the 1 st, 2 nd, 3 rd, 4 th and 5 th weeks after admission and on the day of hospital discharge. The levels of tumor necrosis factor-α(TNF-α), interferon-γ(IFN-γ), interleukin(IL)-5, IL-6 and IL-10 in plasma samples were measured by the enzyme linked immunosorbent assay. RESULTS: The five cytokines in patients with exfoliative dermatitis showed an increasing trend at the initial stage of treatment. Among them, the levels of TNF-α, IL-5 and IL-10 reached a peak and then dropped rapidly to form a plateau, and the levels of IFN-γ and IL-6 were slightly increased and the duration of increase was shorter than that of other cytokines. The levels of TNF-α, IFN-γ, IL-5 and IL-6 in patients with erythema multiforme remained within the detection limits in the detection process. Only a few patients showed a short-term increase, the IL-10 level showed a slight increase at the initial stage and then decreased to the plateau stage. The levels of TNF-α, IFN-γ and IL-6 in patients with bullous epidermal necrolysis increased rapidly at the initial detection stage for a short period of time, and then decreased sharply. The level of IL-5 remained at the detection limit, and the IL-10 level showed alternative rising and falling pattern. Part of the dynamic change of cytokines in patients with exfoliative dermatitis and bullous epidermal necrolysis was similar. CONCLUSION: The levels of TNF-α, IFN-γ, IL-5, IL-6, and IL-10 in OMDT patients changed with the progression of the disease at the early treatment stage, and the degree of change was related to the type of rash. Among them, the levels of TNF-α and IL-10 showed dynamic changes due to the progression of the disease, which could be considered as effect biomarkers to evaluate the severity and progression of the disease, and provide a reference for the rational treatment of patients.

Role of NRF2 signaling pathway in trichloroethylene-induced oxidative stress in HepG2 cells / 中国职业医学

OBJECTIVE: To investigate the role of nuclear factor erythroid-2-related factor 2(NRF2) signaling pathway in trichloroethylene(TCE) induced oxidative stress in human liver cancer HepG2 cells. METHODS: HepG2 cells in the exponential growth phase were randomly divided into control group and low-, medium-and high-dose groups, and the cells were stimulated with TCE at the final concentrations of 0, 2, 4 or 8 mmol/L respectively for 24 hours. After TCE exposure, the cells were collected. The activity of superoxide dismutase(SOD) was measured by 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulphenyl)-2 h-tetrazole monosodium salt method.The activities of catalase(CAT) and glutathione peroxidase(GSH-Px) were detected by enzymatic method. The level of malondialdehyde(MDA) was detected by thiobarbituric acid method. The level of 8-hydroxydeoxyguanosine(8-OHDG) was detected by enzyme-linked immunosorbent assay. The mRNA expression of NRF2, heme oxygenase(HO1), glutamate-cysteine ligase catalytic subunit(GCLC), NAD(P) quinone oxidoreductase 1(NQO1) were detected by real-time polymerase chain reaction and the protein expression of NRF2, HO1, GCLC, NQO1 were detected by Western blotting. RESULTS: The activity of CAT in HepG2 cells decreased in the 3 doses drug exposure groups(all P<0.05). The activity of GSH-Px increased(all P<0.05), while the level of MDA in HepG2 cells decreased in low-dose group compared with the control group(P<0.05). There was no statistical significance in SOD activity and 8-OHDG level of HepG2 cells among these 4 groups(all P>0.05). The mRNA and protein relative expression of NRF2 and GCLC in HepG2 cells decreased in the low-and medium-dose groups(all P<0.05) compared with the control group. The mRNA relative expression of HO1 decreased(all P<0.05). The HO1 protein relative expression of HepG2 cells increased in low-dose group compared with the control group(P<0.05). The mRNA and protein relative expression of NQO1 in low-dose group increased(both P<0.05). The protein relative expression of HO1 in HepG2 cells in medium-dose group was lower than that in control group(P<0.05).The mRNA and protein relative expression levels of NRF2 and NQO1 increased in HepG2 cells of high-dose group(all P<0.05) and the mRNA relative expression of HO1 increased in HepG2 cells of high-dose group(all P<0.05) compared with the other 3 groups. CONCLUSION: The low and medium dose TCE stimulation can cause oxidative stress in HepG2 cells and decrease the antioxidant enzyme activity. The high dose TCE stimulation to HepG2 cells can activate NRF2 signaling pathway, thus upregulating the expression of downstream antioxidant enzymes HO1, GCLC and NQO1, and relieving the oxidative damage caused by TCE.

Correlation between cytokine levels and liver function damage in patients with occupational medicamentosa-like dermatitis due to trichloroethylene / 中国职业医学

OBJECTIVE: To investigate the correlation between plasma cytokine levels and liver functions in patients with occupational medicamentosa-like dermatitis due to trichloroethylene(OMDT). METHODS: A total of 22 OMDT patients were selected as research subjects using judgment sampling method. Blood samples were collected from patients on the 1 st, 2 nd, 3 rd, 4 th, and 5 th week of admission and the day of hospital discharge. The automatic biochemical instrument was used for detecting the index of serum liver function. The levels of cytokines including tumor necrosis factor-α(TNF-α), interferon-γ(IFN-γ), interleukin(IL)-5, IL-6, and IL-10 in plasma were measured by enzyme-linked immunosorbent assay. The Spearman correlation analysis was performed to analyze the correlation between cytokines and liver function in 15 patients with exfoliative dermatitis. RESULTS: The levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), total bilirubin(TBIL), direct bilirubin(DBIL), glutamyl transpeptidase(GGT), and total bile acid(TBA) of OMDT patients on the 1 st week of admission increased(P<0.05), while total protein(TP) and albumin(ALB) decreased(P<0.05) compared with the results at discharge(a stage of recovery). The correlation analysis results of patients with exfoliative dermatitis showed that: the levels of TNF-α, IFN-γ and IL-6 were negatively correlated with the levels of TP and ALB respectively(P<0.05), the level of IL-5 was negatively correlated with TBIL(P<0.05), and the level of IL-10 was negatively correlated with ALB(P<0.05) in the 1 st week. The level of IL-6 was positively correlated with ALT(P<0.05) in the 2 nd week. The level of TNF-α was positively correlated with TBIL(P<0.05), the level of IL-10 was positively correlated with AST(P<0.05) in the 3 rd week. The levels of TNF-α and IL-10 were positively correlated with AST and ALT respectively(P<0.05), the level of IFN-γ was positively correlated with AST(P<0.05) in the 4 th week. The levels of IL-6 and IL-10 were positively correlated with ALT and GGT(P<0.05), and the levels of TNF-α and IFN-γ were positively correlated with AST(P<0.05) in the 5 th week. The level of TNF-α was negatively correlated with DBIL(P<0.05) and was positively correlated with TBA(P<0.05) at discharge.CONCLUSION:s Patients with OMDT are frequently accompanied with severe liver function damage at the early stage. The level of plasma cytokines(TNF-α, IFN-γ, IL-6 and IL-10) might correlate with the severity of liver dysfunction.

Report on the follow-up study of occupational medicamentosa-like dermatitis induced by trichloroethylene / 中国职业医学

OBJECTIVE: To understand the long-term prognosis of patients with occupational medicamentosa-like dermatitis induced by trichloroethylene( OMDT) after recovery. METHODS: A total of 185 patients with OMDT were surveyed through landline and correspondence after recovery. Based on the individual's wishes,19 patients( follow-up examination group)were followed up and arranged for health examination in hospital. RESULTS: Seventy-one cases of OMDT was successfully follow-up. The success rate was 38. 4%( 71/185). Among the 71 cases who were successfully followed up,64. 8%( 46/71)cases complained of physical discomfort. The main complain included skin itching,allergy,upper respiratory tract infection or frequent fever,xerophthalmus,osteonecrosis of femoral head. The 19 cases in the follow-up examination group had different degrees of skin itching,dryness and mild melanosis. The abnormal rates of schirmer I test were 42. 1%( 8/19)and 52. 6%( 10/19) in the left and right eye,respectively. The abnormal rate of tear break-up time in both left and right eyes was 84. 2%( 16/19). The highest positive rate of patch test was chloral hydrate( 100. 0%). There was no abnormality in body temperature,superficial lymph nodes,blood routine,urine routine,liver function and autoimmunity antibody. There was no new rash. CONCLUSION: Different degree of long-term prognosis can occur in OMDT recovery patients. Xerophthalmus and osteonecrosis of femoral head are the major sequelae. Chloral hydrate,which is the main metabolite of trichloroethylene,may be the causative culprit compound for OMDT.

Analyzing the epidemiologic characteristics of occupational medicamentosa-like dermatitis induced by trichloroethylene in Guangdong Province / 中国职业医学

OBJECTIVE: To analyze the epidemiologic characteristics of occupational medicamentosa-like dermatitis induced by trichloroethylene( OMDT) in Guangdong Province. METHODS: The data of OMDT cases diagnosed by Guangdong occupational disease diagnosis institutions from 1988 to 2016 was collected and analyzed. The data of OMDT come from medical records,the National Occupational Disease Network Reporting System and literature retrieval. RESULTS: A total of 475 cases of OMDT were diagnosed in Guangdong Province during 1988 to 2016. The recovery rate was 91. 4%( 434/475),and the fatality rate was 8. 6%( 41/475). All cases had a clear history of trichloroethylene( TCE) exposure and had not been exposed to TCE prior to the present exposure. The median incubation period was 30 days. The exceeding standard rate of TCE time weighted average concentration was 80. 7%( 171/212),and the exceeding standard rate of urine trichloroacetic acid was 75. 0%( 123/164). The years that have most OMDT cases were from 1999 to 2006,which accounted for 64. 0%( 304/475); but there was no seasonal aggregation. The enterprises of OMDT cases concentrated in the Pearl River Delta Region,with Shenzhen City and Dongguan City accounting for 62. 9%. The median age of onset was22 years old,81. 9% of cases were 30 years old or below. The male-female ratio was 1. 2 ∶ 1. 0; 57. 7%( 274/475) cases were from southern China. Meanwhile,95. 4%( 453/475) of the cases came from the manufacturing industry such as electronics factory,hardware factory,electroplating factory and others. CONCLUSION: The distribution of OMDT cases on area,age of onset,native place and occupation in Guangdong Province showed a certain aggregation.

Expression of IL-23 and IL-17 in immune injury of the liver of mice sensitized by trichloroethylene and aggravated by Poly I:C / 中国职业医学

OBJECTIVE: To observe the expression of interleukin(IL)-23 and IL-17 in the liver of mice sensitized by trichloroethylene(TCE), and to explore the role of IL-23 and IL-17 in polyinosinic: polycytidylic acid(Poly I:C) exacerbated TCE-sensitized mice with immune injury of the liver. METHODS: Female specific pathogens free BALB/c mice were randomly divided into control group(n=5), solvent control group(n=5), TCE group(n=20), and TCE+Poly I:C group(n=20). A TCE-sensitized mouse model was established in TCE group and TCE+Poly I:C group. Three hours before the last challenge, mice in TCE+Poly I:C group was intraperitoneally injected with a mass concentration of 0.5 g/L poly I:C, 100 μL per mouse. The two groups of mice were divided into sensitized and non-sensitized subgroups according to the results of skin sensitization. After 48 hours of the final challenge, serum alanine aminotransferase(ALT) was detected by colorimetric method. The histopathological changes of mouse liver were observed, and the expression of IL-23 and IL-17 in liver tissues was detected by immunohistochemistry and Western blotting method. RESULTS: The sensitization rates of TCE and TCE+Poly I:C groups were 35.0%(7/20) and 40.0%(8/20) respectively, with no significantly statistical difference(P>0.05). Pathological examination showed that there was cell edema in some areas of the liver tissues of mice in the TCE-sensitized subgroup, while the TCE+Poly I:C sensitized subgroup showed cell vacuolar degeneration and loose cytoplasm. Serum ALT activity and the expression of IL-23 and IL-17 in liver tissues in the TCE-sensitized subgroup were higher than that in the blank control group, the solvent control group and the TCE non-sensitized subgroup(P<0.05). Serum ALT activity and IL-23 and IL-17 expression in the TCE+Poly I:C sensitized subgroup were higher than that in the TCE-sensitized subgroup(P<0.05). The relative expression of IL-23 and IL-17 protein in liver tissues in TCE-sensitized subgroup was higher than that of the blank control group and the solvent control group(P<0.05), while that in TCE+Poly I:C sensitized subgroup was higher than that of TCE-sensitized subgroup(P<0.05). CONCLUSION: IL-23/IL-17 axis may play an important role in the development of immune injury of liver in the TCE-sensitized mice and Poly I:C exacerbated TCE-sensitized mice.

Trichloroethylene Hypersensitivity Syndrome: Should Be Considered When Diagnosing DRESS Syndrome

Trichloroethylene (TCE) is an organic solvent that is used for degreasing and removing impurities from metal parts. However, this solvent's characteristics and hypersensitivity can produce clinical patterns and laboratory data that mimic drug rash with eosinophilia and systemic symptoms (DRESS) syndrome. Thus, exposure confirmation is critical to making an accurate diagnosis. This is a case of TCE-induced hypersensitivity syndrome (TCE HS) in a 24-year-old Indonesian man who was working in an electro-plating business. He was admitted to a referral hospital after one month of working, and exhibited a fever with skin symptoms. He was administered immunosuppressive therapy based on an assumed diagnosis of DRESS syndrome, although he subsequently experienced cardiac arrest and did not respond to resuscitation. An investigation into his disease history confirmed that he was prescribed medications one week before he developed the skin disease, and had been periodically exposed to TCE for the previous 4 weeks. Based on these findings, it was believed that his clinical course was caused by TCE HS, rather than DRESS syndrome.

Association of occupational medicamentosa-like dermatitis induced by trichloroethylene and infection with human herpesvirus 6 and cytomegalovirus / 中国职业医学

OBJECTIVE: To explore the potential association between occupational medicamentosa-like dermatitis induced by trichloroethylene( OMDT) and past infection,reactivation and recent infection of human herpesvirus 6( HHV6) and human cytomegalovirus( HCMV). METHODS: Twenty OMDT patients were recruited as case group by using judgment sampling method. Twenty healthy workers occupationally exposed to trichloroethylene for more than half a year were randomly selected as exposure group. Twenty healthy people with no exposure history to trichloroethylene were randomly selected as control group. The enzyme linked immunosorbent assay was used to qualitatively determine the titer of HHV6 and HCMV immunoglobulin( Ig) G,Ig M antibodies from serum samples of these subjects. The polymerase chain reaction was used to qualitatively detect HHV6 and HCMV DNA from whole blood DNA samples of these subjects. The differences of previous infection rate,reactivation rate and recent infection rate of HHV6 and HCMV among these three groups of patients with different clinical types of OMDT were analyzed. RESULTS: The prevalence of HHV6 and HCMV infection in the case group was higher than that in the control group,and the difference was statistically significant( 65. 5% vs 20. 0%,75. 0% vs15. 0%,P < 0. 017). The reactivation rate of HHV6 and HCMV in the case group was higher than that in the control group,but the difference was not statistically significant( P > 0. 017). The recent infection rate of HHV6 and HCMV in the case group was not significantly different from that in the control group( P > 0. 017). There was no significant difference in the past infection rate,reactivation rate and recent infection rate of HHV6 and HCMV between the exposure group and the control group( P > 0. 05),meanwhile in different clinical types of OMDT patients( P > 0. 05). CONCLUSION: OMDT may be associated with past infection of HHV6 and HCMV.

Screening of allergens of trichloroethylene-induced occupational medicamentosa-like dermatitis / 中国职业医学

OBJECTIVE: To screen the allergens of trichloroethylene-induced occupational medicamentosa-like dermatitis( OMDT) by patch test,and explore methods for OMDT auxiliary diagnosis and trichloroethylene( TCE) allergic population screening. METHODS: A total of 20 subjects diagnosed with OMDT were selected as case group,and 22 nonOMDT healthy workers exposed to TCE≥12 weeks were selected as control group. Different concentrations of TCE and its main metabolites such as chloral hydrate( CH),trichloroethanol( TCOH) and trichloroacetic acid( TCA) were used as allergens in a skin patch test in workers of these two groups. Another 20 new workers exposed to TCE < 12 weeks without OMDT were tested as validation group. They were tested with a patch test at a mass fraction of 15. 00% CH and follow-up observations were performed until 12 weeks of TCE exposure. RESULTS: The patch test of TCE,CH,TCOH and TCA were negative in the control group. In the case group,the patch test positive rate for 50. 00% TCE was 10. 00%,the patch tests were negative in 25. 00%,10. 00% and 5. 00% TCE. The CH patch test positive rate was 100. 00% with the CH mass concentrations of 15. 00%,10. 00% and 5. 00%. The TCOH patch test positive rates were 90. 00%,75. 00% and50. 00%,with the corresponding concentration of 5. 00%,0. 50% and 0. 05%. The TCA patch test positive rates were50. 00% and 0. 00% with the TCA concentrations of 5. 00% and 0. 50% respectively. When the mass concentration was5. 00%,the patch test positive rates in case group from high to low were CH,TCOH,TCA and TCE( P < 0. 01). And the patch test positive rates of CH and TCOH showed no statistical significant difference( P > 0. 05). The patch test positive rate of TCOH increased with increase of TCOH mass concentrations( P < 0. 01). The patch test positive rates for 5. 00%TCA was higher than that of 0. 50% TCA( P < 0. 01). The patch test positive rate in 0. 50% TCOH was higher than that of 0. 50% TCA( P < 0. 01). In the validation group,the patch test of 15. 00% CH was negative,and there was no OMDT case found during the follow-up 12 weeks of TCE exposure. CONCLUSION: The metabolites CH and TCOH of TCE may be the main allergens of OMDT after exposure to TCE. The CH and TCOH patch test can be an auxiliary diagnosis method for OMDT. The CH patch test could be used as a method for screening population allergic to TCE.

Simultaneous detection of 45 kinds of common organic compounds in workplace air by gas chromatography / 中国职业医学

OBJECTIVE: To explore the feasibility of simultaneous detection of 45 kinds of common organic compounds in workplace air by solvent desorption-gas chromatography method.METHODS: A total of 45 kinds of common organic compounds such as benzene,1,2-dichloroeyhane,n-hexane and trichloroethylene in workplace air were collected with activated carbon tube and desorbed with carbon disulfide,separated by capillary chromatographic column,and detected with flame ionization detector.RESULTS: There was good linear relationship in the selected range.The correlation coefficients was 0.999 92-0.999 99.The detection limit was 0.03-0.30 mg/L and the minimum detectable concentration range was 0.01-0.20 mg/m~3( sample volume was 3.00 L).The average desorption efficiencies was 75.4%-105.7%.The within-run and between-run relative standard deviations were 0.4%-6.7% and 1.8%-7.9%,respectively.The sampling efficiency was 91.9%-100.0%.CONCLUSION: The method is simple,high sensitivity and good precision,which can be used for simultaneous detection of 45 kinds of common coexisting organic compounds in workplace air.

Predicting the sensitizing potency of trichloroethylene by in vitro test / 中国职业医学

OBJECTIVE: To predict the sensitizing potency and optimal sensitization dose of trichloroethylene( TCE) by an in vitro skin sensitization test on a human acute monocytosis cell line( THP-1).METHODS: THP-1 cells were cultured in vitro and exposed to 2,4-dinitrochlorobenzene( DNCB),sodium dodecyl sulfate( SDS),tert-butylhydroquinone( tBHQ)and TCE for 24 hours.Flow cytometry was used to detect the expression of cell surface marker such as cluster of differentiation( CD) 86 and CD54,and the optimal dose range for sensitization detection was determined.With the relative fluorescence intensity( RFI),CD86 ≥ 150 and CD54 ≥ 200 as the standard,the sensitizing potency and optimal sensitization dose of TCE were predicted.RESULTS: The concentration range of reagents for sensitization test on THP-1 cells was the dose range at which the relative cell survival rate reached 75.0%-100.0%.DNCB at the doses of 20.83,25.00 and 30.00 μmol/L,tBHQ at the dose of 5.80 μmol/L,TCE at the doses of 8.33,10.00 and 12.00 mmol/L,can cause sensitivity.SDS was recognized as a negative sensitizer.The expression of CD86 and CD54 was the highest when the concentration of TCE was 8.33 mmol/L,which was considered as the best sensitization dose.CONCLUSION: The optimum sensitization dose of TCE is 8.33 mmol/L,which can provide the basis for dose design in future study of TCE sensitization pathways.

Effect of cathepsin L activation on trichloroethylene-induced skin allergy in mice / 中国职业医学

OBJECTIVE: To observe the expression of cathepsin L( CTSL) on the skin of trichloroethylene( TCE)-sensitized mice,and explore the mechanism of CTSL in TCE-induced immunological skin damage. METHODS: The specific pathogen free female BALB/c mice were randomly divided into blank control group( n = 5),solvent control group( n = 5),TCE group( n = 15) and inhibitor group( n = 15). Skin sensitization experiments were performed according to the maximum guinea pig test method. The TCE group and inhibitor group were divided into sensitized subgroups and non-sensitized subgroups according to skin sensitization results. The skin tissues were taken 72 hours after the last TCE challenge.Hematoxylin-eosin staining was used to observe the pathological structure of skin tissues and measured the thickness of epidermis. The level of Ctsl mRNA was examined by real-time quantitative polymerase chain reaction,and the expression of CTSL, interleukin( IL)-6 and IL-17 were studied by immunohistochemical staining technique. RESULTS: The sensitization rate of TCE group and inhibitor group were 40. 0%(6/15) and 33. 3%(5/15) respectively. There was no statistical difference in the sensitization rate between the two groups( P > 0. 05). The thickness of epidermis and relative expression of Ctsl mRNA,CTSL,IL-6 and IL-17 in TCE sensitized subgroup and inhibitor sensitized subgroup were higher than that in blank control group,solvent control group,TCE non-sensitized subgroup and inhibitor non-sensitized subgroup(P < 0. 05). The above-mentioned indexes were higher in TCE sensitized subgroup than that in inhibitor sensitized subgroup( P < 0. 05). The relative expression of Ctsl mRNA,CTSL,IL-6 and IL-17 in skin of TCE sensitized subgroup were positively correlated between any two indexes( P < 0. 05). CONCLUSION: CTSL activation may play an important role in immunological skin damage of TCE-sensitized mice,which may be related to the promotion of IL-6 and IL-17 release.

Simultaneous determination of trichloroethylene and trichloroethanol in blood by liquid-liquid extraction-gas chromatography / 中华劳动卫生职业病杂志

Objective@#To establish a method for determing the trichloroethylene(TCE)and trichloroethanol(TCOH)in blood samples by liquid-liquid extraction-gas chromatography with electron capture detector.@*Methods@#With this method,ether was used as extraction solvent and trichloromethane was used as an internal standard. The whole blood sample was extracted with ether, and dehydrated by anhydrous sodium sulfate. Then the analytes were separated on HP-5 capillary column(30m×0.32mm×0.15μm)and detected byECD.The retention time was for qualitative analysis and the internal standard was for quantitation.@*Results@#The standard curves of TCE and TCOH showed significant linearity between 95.5μg/L-7640.0μg/L(r=0.9997)and 19.0μg/L-1520.0μg/L(r=0.9992). The average recovery was 95.5%-103.6%.The intra-day and inter-day precisions(RSD)were 2.5%-6.8%(n=6)and 1.6%-4.3%(n=6) respectively. The detect limit of TCE and TCOH were 2.10 μg/L and 0.56μg/L(S/N=3)respectively.The blood can be kept 7 days at-20℃ refrigerator without significantly loss.@*Conclusion@#This method is proved to be simple,practical and highly sensitive. It can satisfy the request for the determination of blood samples of humans exposed to TCE.

Detection of HLA-B*13:01 gene by dual allele-specific real-time polymerase chain reaction in patients with trichlorethylene-induced dermatitis / 中华劳动卫生职业病杂志

Objective@#To investigate the detection of a human leukocyte antigen-B (HLA-B) allele HLA-B*13:01 by dual allele-specific real-time polymerase chain reaction (PCR) in patients with trichlorethylene-induced dermatitis.@*Methods@#A total of 20 patients with trichlorethylene-induced dermatitis who were admitted and treated from January 2014 to October 2016 were enrolled as case group, and 20 persons who underwent physical examination from January to October, 2016 were enrolled as control group. Peripheral cubital venous blood samples were collected from all subjects, and dual allele-specific real-time PCR was used to detect the HLA-B*13:01 gene. The two groups were compared in terms of the proportion of subjects carrying HLA-B*13:01 gene.@*Results@#There were no significant differences between the case group and the control group in median age (25.0 years vs 27.0 years, Z=0.30, P>0.05) and the proportion of male subjects (60.0% vs 70.0%, χ2=0.44, P>0.05) . The mean time of exposure to trichloroethylene was 30.8 days in the case group, while the subjects in the control group were not exposed to trichloroethylene. The case group had a significantly higher frequency of HLA-B*13:01 gene than the control group (80.0% vs 20.0%, χ2=14.40, P<0.01) with an odds ratio of 16.00.@*Conclusion@#Dual allele-specific real-time PCR can be used for detection of the HLA-B*13:01 gene in patients with trichlorethylene-induced dermatitis.

An investigation of trichloroethylene-induced effects on histone methylation in L-02 hepatic cells / 中华预防医学杂志

Objective@#To further explore TCE-induced hepatotoxicity and its mechanisms by identification of trichloroethylene (TCE) induced abnormal histone methylation in human liver cells.@*Methods@#L-02 cells were treated with 0 and 8 mmol/L TCE for 24 h. Histones were extracted by acid. Liquid chromatography electrospray ionization tandem mass spectrometry (ESI-LC-MS/MS) were used to identify and quantify TCE related histone methylations. TCE induced abnormal methylation of H3K79 me2 and H3K79 me3 were validated by Western blot analysis. The further analysis of the function of histone abnormal methylation modifications were done by single cell gel electrophoresis (SCGE) and Western blot analysis of p53 and ɤH2AX.@*Results@#After treatment with TCE for 24 h in L-02 cells, the 36 TCE related histone methylation sites in 28 peptide segments were identified by MS. After treatment with TCE in concentrations of 0 and 8.0 mmol/L in L-02 cells for 24 h, the relative expression level of histone H3K79 me3 were 1.00±0.06, 0.70±0.09 (t=15.01, P=0.015); the relative expression level of histone H3K79 me2 were 1.00±0.05, 0.74±0.07 (t=16.69, P=0.018); the Olive Tail Moment about DNA damage were 1.46±0.28, 3.12± 0.68 (t=15.22, P=0.018); the relative expression levels of p53 were 1.00±0.04, 1.24±0.04 (t=18.71, P= 0.012); and the relative expression levels of ɤH2AX were 1.00 ± 0.03, 1.56 ± 0.11 (t=8.32, P=0 045).@*Conclusion@#TCE can induce changes in the relative expression level of H3K79 me2 and H3K79 me3 in L-02 cell, and induce DNA damage, suggesting that TCE may induce changes in the relative expression level of H3K79 me2 and H3K79 me3 by DNA damage.

Recombinant human tumor necrosis factor receptor type Ⅱ-IgG Fc fusion protein for treatment of occupational medicamentosa-like dermatitis induced by trichloroethylene / 中华劳动卫生职业病杂志

Objective@#To investigate the efficacy and safety of the recombinant human tumor necrosis factor receptor Ⅱ-IgG Fc fusion protein (rhTNFR: Fc, etanercept) for the treatment of occupational medicamentosa-like dermatitis induced by trichloroethylene (OMLDT) .@*Methods@#In September 2011 to February 2016, 12 patients with OMLDT were treated with etanercept 25 mg, subcutaneous injection, twice per week, doubling of first dose. The course of treatment was 6 weeks. The drug eruption area and severity index (DASI) score, the proportion of patients achieving a 50%, 75% and 90% reduction in DASI (DASI50, DASI75, DASI90) and the serum level of TNF-α were used to assess the efficacy at different times. Adverse reactions were also recorded and evaluated. The results were statistically analyzed by nonparametric Friedman test and repetitive measurement ANOVA using the software SPSS19.0.@*Results@#After 4 weeks treatment, the DASI score decreased form 56.33±7.02 to 0.50±0.91 (P<0.01) . The DASI50, DASI75 and DASI90 were all increased to 12 (100%) . The serum level of TNF-α decreased form (43.74±41.62) pg/ml to (3.03±0.47) pg/ml (P<0.01) . Statistically significant difference was observed from the above indexes. There were no adverse reactions in clinical application.@*Conclusion@#Recombinant human tumor necrosis factor receptor Ⅱ-IgG Fc fusion protein may be a safe and effective drug in the treatment of OMLDT.