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Objective: To investigate the role of surfactant associated protein-A (SP-A) in the development and progression of silicosis, and its mechanism. Methods: Homozygous and heterozygous mice of SP-A knockout of specific pathogen free (SPF) grade were selected for mating, and mice with SP-A-/- genotype were selected for subsequent experiments. SP-A wild-type (SP-A+/+) and SP-A-/- mice were divided into SP-A+/+ control group, SP-A-/- control group, SP-A+/+ silicosis group and SP-A-/- silicosis group with six mice in each group by random number table method. Mice in both silicosis groups were given 20.0 μL 250 g/L silica suspension by tracheal exposure, and mice in both control groups were injected with 0.9% sodium chloride solution at the same volume. On the 28th day after modeling, mice were sacrificed. Lung tissues were used for lung histopathology examination. The apoptosis of alveolar type Ⅱ epithelial cells of mice was detected by TUNEL method. The mRNA expression of B-lymphoblastoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), cysteinyl aspartate specific proteinase (Caspase)-3 and Caspase-9 in lung tissues of mice was detected by quantitative real-time polymerase chain reaction. Results: The histopathological result of mice showed that thickened alveolar septum, scattered silicon nodule and collagen fiber formation were observed in the mice lungs of SP-A+/+ silicosis group, and a large number of inflammatory cells were observed in silicosis nodule, after exposure to silica dust. SP-A-/- silicosis group resulted in a more severe pulmonary inflammation and interstitial fibrosis compared to SP-A+/+ silicosis group. The apoptosis of alveolar type Ⅱ epithelial cells and the mRNA relative expression levels of Bax, Caspase-3 and Caspase-9 in lung tissues of mice in each silicosis groups were increased compared with their control groups (all P<0.05). The above four indexes of mice in SP-A-/- silicosis group were higher than those in SP-A+/+ silicosis group (all P<0.05). There was no significant difference in the expression of Bcl-2 mRNA in lung tissues of these four groups (P>0.05). Conclusion: Knockout of SP-A can aggravate inflammation and pulmonary fibrosis in silicosis model mice, and promote apoptosis of alveolar type Ⅱ epithelial cells. The mechanism may be related to the Bcl-2/Bax/Caspase-3 signaling pathway which affects the apoptosis of mitochondrial pathway.
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OBJECTIVE: To explore the effect of ultra-high frequency radiation on psychomotor neurological behavior in workers with exposure. METHODS: A total of 85 workers who exposed to 40.68 MHz radiofrequency were recruited as the exposure group by judgment sampling method. A group of 121 workers without occupational EMR exposure were recruited as the control group. Workers in both groups were from the same shoe factory. The electric field intensity(EFI) of ultra-high frequency radiation of workplace in the exposure group was measured. The computerized neurobehavioral evaluation system in Chinese version 3 was used to evaluate the psychomotor neurobehavioral function which included the neurobehavioral ability index(NAI) of simple visual reaction time(SVRT), digital screening and fit curve and the general NAI(GNAI) of the above 3 indexes. RESULTS: The median of the workplace EFI of ultra-high frequency radiation in the exposure group was 119.0 V/m, and all of them exceeded the national occupational exposure limit. NAI of digital screening in exposure group was lower than that in the control group(P<0.05). There is no statistically significant difference in the NAI of SVRT, fit curve and GNAI(P>0.05). Meanwhile, there is no statistically significant difference in abnormal rate of NAI of SVRT, digital screening, fit curve and GNAI(P>0.05). The results of multiple linear regression analysis showed that the ultra-high frequency radiation EFI exposure was negatively correlated with NAI of digital screening(P<0.05) after eliminating the influence of confounding factors such as age, working age, gender, education level, smoking, drinking and staying up late. CONCLUSION: The digital screening of psychomotor neurobehavioral function in the exposure workers was adversely affected by the ultra-high frequency radiation. The neural behavioral ability of eye-hand coordination and precise movement may be the specific performance.
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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.
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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.
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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.
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OBJECTIVE: To explore an objective evaluation mode for emergency response capacity on sudden poisoning incidents. METHODS: Based on the health emergency drills and blind design,22 teams in Guangdong Province were recruited to participate in the first round of evaluation,including blind sample analysis,theoretical examination( poisoning medical rescue,detection and investigation) and skills assessment( poisoning medical care,poisoning investigation,personal protection,poisoning detection and emergency decision-making). Then,the top 10 teams in the first round of evaluation were proceeded to desktop exercise in the second round of evaluation. The evaluation results were compared with the local gross domestic product( GDP) from 2011 to 2015 by Spearman rank correlation analysis. RESULTS: The median scores of the 4 sections were as follows: blind sample analysis was 71. 0,theoretical examination was 61. 4,skills assessment was 76. 5,and the desktop exercise was 55. 0. The rates of excellent for assessment of blind sample analysis,theoretical examination and skills assessment were 22. 7%,4. 5% and 0. 0%,while the failure rates were 31. 8%,45. 5% and 4. 5%,respectively. The rates of failure in medical rescue and investigation in theoretical examination were63. 6% and 50. 0%,the rates of failure in medical rescue and investigation in skills assessment were 40. 9% and 31. 8%,respectively. The middle-grade and passing rates of the top 10 teams in the desktop exercise were 10. 0%,and the failure rate was 80. 0%. There was a moderate positive correlation between the emergency response capacity for emergent poisoning and local GDP( Spearman rank correlation coefficient > 0. 700,P < 0. 05). CONCLUSION: The evaluation mode of emergency response capability assessment combined with actual combat and desktop emergency drill is established successfully. It can objectively test the assessment of emergency response capabilities.
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OBJECTIVE: To evaluate the ability of health emergency drill for sudden poisoning incidents in Guangdong Province. METHODS: A double-blinded method was used to organize 22 teams in Guangdong Province to conduct a health emergency drill which contained preliminary and repeated drill. The preliminaries contained blind sample analysis,theoretical examination and skills assessment. The repeated drills was desktop network exercise carried out for the teams ranked top 10 in the preliminaries. RESULTS: In the preliminary round,the median( M) of total score among the 22 teams was 72. 5. Among them,blind sample analysis,theoretical examination and skills assessment were 71. 0,61. 4 and 76. 5,respectively. The total score of skill assessment was higher than that of theoretical assessment( P < 0. 05). The passing rate of 22 teams was 68. 2%(15/22),and the failure rate was 31. 8%(7/22). The failing teams all came from the nonPearl River Delta region. The total preliminary scores,passing rate,the total scores of blind sample analysis and skills assessment of the teams in Pearl River Delta Region were higher than that in the non-Pearl River Delta region( P < 0. 01).In the theoretical examination,the scores of detection and investigation were both higher than that of medical rescue( P <0. 05). For the skills assessment,the scores of decision-making,personal protection and poisoning detection were in the top three,the scores of the medical rescue and investigation were relatively low( P < 0. 05). In the repeated round,the M of desktop exercise was 55. 0,passing rate was 20. 0%,and the failure rate was 80. 0%. CONCLUSION: The health emergency response capacity for sudden poisoning incidents in Guangdong Province needs to be improved. The construction of emergency response capacity for emergency poisoning in the non-Pearl River Delta region should be strengthened,especially the training on strengthening theoretical and practical knowledge of poisoning medical treatment and poisoning investigation.