[The study on biological exposure index of occupational exposure to arsenic and its inorganic compounds].

Objective: To establish biological exposure index (BEI) of occupational exposure to arsenic and its inorganic compounds through occupational epidemiology and the regression analysis of internal and external exposure of workers. Methods: In November 2021, 125 workers with occupational exposure to arsenic and its inorganic compounds and 49 office administrators in a non-ferrous metal smelter in Yunnan Province were selected as the exposure group and control group, respectively. Air samples from the workplace of the study subjects on weekdays were collected and arsenic concentrations were determined. Urine samples were collected in end-of-work weekend and high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was used to detect the levels of trivalent inorganic arsenic (iAs(3+)) , pentavalent inorganic arsenic (iAs(5+)) , monomethyl arsenic (MMA) and dimethyl arsenic (DMA) in urine. The correlations between arsenic concentration in the workplace air and arsenic species in urine of workers were analyzed. Arsenic exposure concentration and the level of urinary arsenic (ΣiAs+MMA+DMA) of workers was analyzed by linear regression and the BEI of arsenic and its inorganic compounds in the workplace was proposed based on the results of micronucleus test. Results: The median of time-weighted average concentration (C(TWA)) of arsenic in the workplace air of the exposure group was 0.0116 mg/m(3), and the over-standard rate was 71.2% (89/125) . The concentrations of iAs(3+), iAs(5+), inorganic arsenic (iAs=ΣiAs(3+)+iAs(5+)) 、MMA、DMA and urinary arsenic in the exposure group were higher than those in the control group at the end of shift, and the differences were statistically significant (P<0.05) . The concentration of arsenic in the workplace air had the strongest correlation with the concentration of urinary arsenic at the end of the shift (r(s)=0.909, P<0.001) . The regression equation was lg (y) =7.662+2.968lg (x) (r=0.821, P<0.05) . According to the occupational exposure limit (OEL) of arsenic in China, the concentration of urinary arsenic in the end-of-work weekend was calculated to be 53.2 µg/L. Combined with the results of micronucleus test, the BEI of occupational exposure to arsenic and its inorganic compounds in the workplace was proposed to be 50 µg/L. Conclusion: The urinary arsenic in the end-of-work weekend can be used as a biomarker of occupational exposure to arsenic, and its BEI is recommended to be 50 µg/L.

[Correlation analysis of urinary arsenic species and health effect indicators of occupational arsenic exposure workers].

Objective: To explore the correlation between urinary arsenic and health effects through the determination and analysis of urinary arsenic levels in occupational arsenic exposed workers. Methods: In November 2021, 95 workers exposed to arsenic and its inorganic compounds and 31 administrative personnel from a non-ferrous metal smelter in Yunnan Province were selected as the contact group and control group, respectively. Urine forms of arsenic, blood tumor markers, liver function were detected, and micronucleus test was used to analyze the chromosome damage. The correlation between urine forms of arsenic and health effects were analyzed. Results: Compared with the control group, the concentrations of urinary trivalent inorganic arsenic (iAs(3+)) , pentavalent inorganic arsenic (iAs(5+)) , inorganic arsenic (iAs=ΣiAs(3+)+iAs(5+)) , monomethyl arsenic (MMA) , dimethyl arsenic (DMA) and urinary arsenic (ΣiAs+MMA+DMA) at the end of class in contact group were higher (P<0.05) . There was no statistically significant difference in blood tumor markers and liver function indicators between the two groups (P>0.05) . Compared with the control group, the peripheral blood micronucleus rate and cell micronucleus rate in the contact group were significantly increased (P<0.05) . The urinary arsenic, iAs(5+), inorganic arsenic and DMA were positively correlated with peripheral blood micronucleus rate in contact group (r(s)=0.48, 0.34, 0.37, 0.23, P<0.05) , and the urinary arsenic, iAs(5+), DMA were positively correlated with peripheral blood micronucleus rate (r(s)=0.48, 0.34, 0.26, P<0.05) . Conclusion: There is a significant correlation between different valence states of arsenic in the urine and abnormal health effects of occupational arsenic exposed workers. It is necessary to strengthen the detection of arsenic species in the urine of occupational arsenic exposed workers to better protect their health.

[In vitro activity of ß-lactamase inhibitors avibanvctam and relebactam in combination with ß-lactams against multidrug-resistant Mycobacterium tuberculosis and mutations of resistance genes].

Objective: To evaluate the activity of six ß-lactams in combination with three ß-lactamase inhibitors against mycobacterium tuberculosis(MTB) in vitro. Methods: A total of 105 multidrug-resistant tuberculosis (MDR-TB) strains from different regions of Henan province from January to September 2020 were included in this study. Drug activity of six ß-lactams (biapenem, meropenem, imipenem, doripenem, ertapenem and tebipenem) alone or in combination with ß-lactamase inhibitors (clavulanic acid, avibactam and relebactam) was examined by minimum inhibitory concentration method (MICs) against 105 clinical isolates. Mutations of blaC, ldtmt1 and ldtmt2 were analyzed by PCR and DNA sequencing. Chi-square test was used to compare the antimicrobial activities of different ß-lactam drugs. Results: Out of the ß-lactams used herein, tebipenem was the most effective against MDR-TB and had an MIC50 value of 8 mg/L(χ2=123.70,P=0.001). Besides, after the addition of ß-lactamase inhibitors, the MICs of most ß-lactam drugs were reduced more evidently in the presence of avibactam and relebactam compared to clavulanic acid.Especially, relebactam decreased both the MIC50 and MIC90 of telbipenem by 16-fold, and diluted the MIC of 23 (21.90%) and 41 (39.04%) isolatesby 32-fold and 16-fold.In addition, a total of 13.33% (14/105) of isolates harbored mutations in the blaC gene, with three different nucleotide substitutions: AGT333AGG, AAC638ACC and ATC786ATT. For the strains with Ser111Arg and Asn213Thr substitution in BlaC, the MIC values of the meropenem-clavulanate combination were reduced compared with a synonymous single nucleotide polymorphism (SNP) group. Conclusions: Both avibactam and relebactam had better synergistic effects on ß-lactams than clavulanic acid. The combination of tebipenem and relebactam showed the most potent activity against MDR-TB isolates. In addition, the Ser111Arg and Asn213Thr substitution of BlaC may be associated with an increased susceptibility of MDR-TB isolates to meropenem in the presence of clavulanate.

[Determination of six arsenic species in urine by high-performance liquid chromatography-inductively coupled plasma-mass spectrometr].

Objective: Establishing an analysis method for the detection of six arsenic compounds trivalent arsenic, pentavalent arsenic, methyl arsenic, dimethyl arsenic, arsenical choline and arsenical betaine in urine by high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) and providing a theoretical basis for health assessment of arsenic poisoning patients. Methods: HPLC-ICP-MS was used to detect six arsenic compounds with the hamilton PRP-X100 column and aqueous ammonium phosphate in a gradient elution as mobile phase. Results: There was a good linear relationship in the selected range of six arsenic compounds evidenced by a linear correlation coefficient greater than 0.999. The detection limit of 6 arsenic compounds was 0.46~0.57 µg/L, and the minimum quantitative concentration were 1.52~1.91 µg/L. The recovery rates of six arsenic compounds were 96.5%~106.4%, The within-run and between-run relative standard deviation was 2.9%~6.2% and 3.8%~8.7%. Conclusion: The established method with high accuracy and precision is suitable for detecting arsenic levels in urine of occupational arsenic exposure population.

[Investigation of small airway function of occupational asthma at different stages].

Objective: To analyze the characteristics of small airway dysfunction in patients with occupational asthma, and explore the significance of small airway function indicators in the evaluation of occupational asthma. Methods: A total of 53 patients with occupational asthma diagnosed in our hospital from December 2008 to December 2018 were retrospectively collected in May 2020. 55 healthy people were included as the control group (NC group) and 58 bronchial asthma patients as BA group. The general information and baseline pulmonary function (FVC、FEV(1)、PEF) of the subjects were collected, the pulmonary function were reexamined and small airway function (FEF(25%)pred、FEF(50%)pred、FEF(75%)pred、MMEF(25-75%)pred) were tested at the time of diagnosis and remission. Results: There was no significant difference in pulmonary function and asthma control score (ACT) between OA group and BA group (P=0.356, 0.610, 0.364, 0.430, 0.533, 0.759, 0.426, 0.632) . The incidence of small airway dysfunction in OA group was 77.4%. The indexes of small airway function (FEF(25%)pred, FEF(50%)pred, FEF(75%)pred, MMEF(25-75%)pred) were lower than those in the NC group (P<0.001) . The small airway function indexes of mild and moderate OA patients in remission stage were improved (P=0.029, 0.182) , but the abnormal rate of small airway function was still 62.3%, and there was no significant difference compared with those at the time of diagnosis (P=0.091) . Small airway function (MMEF(25-75%)pred, FEF(50%)pred) was correlated with large airway function (FEV(1)% pred, PEF% pred) (P=0.001) . Conclusion: Small airway dysfunction often occurs and persists in patients with occupational asthma, and has a certain correlation with large airway function indexes.

[The diagnostic value of fractional exhaled nitric oxide in occupational asthma and its correlation with pulmonary function].

Objective: To investigate the value of fractional exhaled nitric oxide (FeNO) in the diagnosis of occupational asthma (OA) , and analyze the correlation between FeNO and pulmonary function in patients with OA. Methods: In October 2019, clinical datas, including pulmonary function, FeNO and blood routine test of 64 workers who applied for the diagnosis of OA in January 2012 to October 2018 in our hospital were collected. The diagnostic value of FeNO in OA was evaluated, FeNO and pulmonary function in different degrees of OA were compared, and the correlations were analyzed. Results: The FeNO value of OA patients [ (58.4±13.1) ppb] was higher than non-OA patients[ (30.1±13.7) ppb] (P<0.05) . The FeNO value of patients with moderate OA [ (68.9±13.8) ppb] was higher than that of patients with mild OA[ (54.2±10.3) ppb] (P<0.05) . The area under the receiver operating characteristic (ROC) curve of FeNO in the diagnosis of OA was 0.9453 (95%CI: 0.8928-0.9978, P<0.05) , the optimal cut-off point is 47.5 ppb, and the sensitivity and specificity are 88.6% and 89.7% respectively. There was negative correlation between FeNO and FEV1% pred (r=-0.454, P<0.01) . Conclusion: FeNO has a clinical application value in the diagnosis of OA. It should be combined with pulmonary function index in practical work.

[The role of renal tubular epithelial cells in cadmium-induced renal fibrosis].

Objective: To investigate the role of renal tubular epithelial cells in cadmium-induced renal fibrosis. Methods: Established a sub-chronic cadmium exposure mouse model and analyzed the progress of renal fibrosis induced by cadmium exposure through Masson staining and immunohistochemistry, and then a co-culture system of renal tubular epithelial cells and renal fibroblasts was established, the levels of proliferation and activation of renal fibroblasts were detected by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and Western blotting. Results: Sub-chronic cadmium exposure led to weight loss in mice (P<0.05) , and the levels of ß-microglobulin (ß-MG) and N-acetyl ß-D-glucosaminidase (NAG) in urine were increased in mice exposed to cadmium (P<0.05) ; pathological analysis revealed that sub-chronic cadmium exposure damaged renal tubular structure, causing infiltration of inflammatory cells and deposition of collagen fiber by Masson (P<0.05) , which in turn induced kidney fibrosis in mice; the results of in vitro co-culture experiments showed that cadmium-exposed renal tubular epithelial cells accelerated the synthesis of collagen in renal fibroblasts and promoted the proliferation and activation of renal fibroblasts (P<0.05) . Conclusion: In the progression of cadmium-induced renal fibrosis, a deleterious renal epithelial-fibroblast cross talk was formed, which may be one of the important mechanisms of cadmium-induced renal fibrosis.

[Study of cytokines in peripheral blood and lung of rats exposed to hard metal dust].

Objective: To study the dynamic changes of cytokines in bronchoalveolar lavage fluid (BALF) and serum of hard metal lung disease (HMLDR) rats. Methods: In March 2019, the rats were randomly divided into 6 groups, each group included 8 rats: control (C) group include 3 groups, hard metal (HM) group include 3 groups. 10 mg HM were administered in HM group by using the pulmonary endotracheal tube. After 4, 8 and 12 week, the BALF and serum were collected for the enzyme-linked immunosorbent assay (ELISA) of matrix metalloproteinase-1 (MMP-1) , tissue inhibitor of metalloproteinase-1 (TIMP-1) and tumor necrosis factor-alpha (TNF-α) . Results: There was no abnormality in behavior, diet and fur of rats in C and HM group at each exposure time. There was no significant difference in body weight between the two groups of rats (P>0.05) . Compared with the C group, the expression of MMP-1 in BALF of rats in HM group were significantly higher in all stages (4, 8 and 12 weeks after exposure) (P<0.05) , the expression of TIMP-1 in BALF of rats in HM group were significantly higher in 8 and 12 weeks after exposure (P<0.05) . However, there was no significant difference in serum MMP-1 and TIMP-1 levels between the two groups in each stage (P>0.05) . There was no significant difference in TNF-α. level in BALF and serum between C and HM group in all stages (P>0.05) . Conclusion: Expression of MMP-1 and TIMP-1 in BALF have reference value in the HMLD auxiliary diagnosis.

First-principles calculations of oxygen octahedral distortions in LaAlO3/SrTiO3(001) superlattices.

The size, shape and connectivity of oxide octahedra are essential for understanding and controlling the emergent functional properties of ABO3 perovskites. Using first-principles calculations, we systematically studied the oxygen octahedral rotation and deformation in LaAlO3/SrTiO3(001) superlattices. Superlattices with electron- or hole-doped interfaces, or both, are compared. The results showed that there are at least three different types of oxygen octahedral distortions in these superlattices, which is more than what had previously been reported in the literature. We demonstrate that interfacial oxygen octahedral coupling and hole-doping, in addition to epitaxial strain, are the key factors underlying the formation of multiple types of oxygen octahedral rotations in these systems. We confirm that oxygen octahedral rotations and deformations play an essential role in insulator-metal transitions. Furthermore, octahedral distortion leads to ferroelectricity like dipole formation with the polarization vector always pointing to the positively charged interfaces.

[Development of the Core Occupational Stress Scale for occupational populations in China].

Objective: To develop the Core Occupational Stress Scale (COSS) for key occupational populations, and to assess the reliability and validity of COSS in China. Methods: According to the literature review, in-depth interview and expert evaluation, the item pool of COSS was established. A total of 20 981 employees (3 703 employees from 2018 and 17 178 employees from 2019) of manufacturing, medical, and traffic polices, etc. from Beijing, Tianjin, Shanghai, Chongqing, Jiangsu, Shandong, Zhejiang, Hunan, Guangdong and Hubei were investigated using convenient sampling of those participating in general or occupational health examination of the day. Item differential test and exploratory factor analysis (EFA) were used to screen items from the item pool; confirmatory factor analysis (CFA) was used to test structure validity; criterion and convergent validity were tested by Pearson correlation. Cronbach's α coefficient was used to test the reliability of the scale. Results: The EFA suggested a four-factor structure for a 17-item version of COSS, which were social support, organization and reward, demand and effort, and control. It explained 62.06% of the total variance and factor loadings ranged from 0.447 to 0.918. The CFA confirmed the hypothesized four-factor model (GFI=0.904, CFI=0.912, RMSEA=0.079). The COSS scores were positively correlated with burnout, depressive symptoms, and effort-reward imbalance scores with r ranging from 0.357 to 0.567 (P<0.05). The total COSS and each dimension of Cronbach's α coefficients were 0.772-0.896. Conclusions: The COSS has good reliability and validity and can be used as an occupation stress assessment for occupational populations in China.

[Changes of serum markers in acute liver injury induced by oral 1, 2-dichloropropane in BALB/cA-nu mice].

Objective: To investigate the characteristics of inflammatory response in BALB/cA-nu mice induced by oral 1, 2-dichloropropane (1, 2-DCP) , and to provides theoretical reference for further study of subchronic, chronic toxicity and carcinogenic mechanism. Methods: From October 2018, Clean grade healthy BALB/cA-nu mice were randomly divided into 5 groups with 10 mice in each group. And 860, 1150, 1500, 1950, 2535 mg/kg 1, 2-DCP were given by gavage respectively. Meanwhile, blank group and solvent control group (corn oil) were set up. Blood samples were collected from eyeballs and liver and bile tissues were collected for histopathological examination within 24 hours after exposure. The expression of alanine aminotransferase (ALT) , total bilirubin (TBLI) , C-reactive protein (CRP) , interleukin-6 (IL-6) , tumor necrosis factor-α (TNF-α) and tumor necrosis factor-ß (TNF-ß) were detected by enzyme-linked immunosorbent assay. Results: With the increase of the dose of 1, 2-DCP, the number of microbubbles in liver cells and the infiltration of inflammatory cells increased gradually. No pathological changes were found in the gallbladder. Compared with the blank group and solvent control group, the content of serum ALT in each exposure group was increased, the serum levels of IL-6 and TNF-ß in 860, 1150, 1950 and 2350 mg/kg exposure groups were increased, the serum TNF-α and TBLI levels in 1 950, 2535 mg/kg groups were significantly higher (P<0.05) . The levels of ALT, TBLI and TNF-ß in serum of female mice were significantly different (P<0.05) . There were significant differences in ALT, TBLI, CRP, IL-6, TNF-α, TNF-ß in serum of male mice (P<0.05) . Conclusion: Oral 1, 2-DCP may cause acute liver injury in BALB/cA-nu mice and increase the expression of serum inflammatory factors. Moreover, the types of inflammatory factors activated in male mice are more than those in female mice.

[Analysis of direct economic burden of occupational asthma].

Objective: To analyze the direct economic burden of occupational asthma patients and provide economic basis for the government to rationally allocate health resources. Methods: In September 2019, colleted the case data of 53 patients diagnosed with occupational asthma who were hospitalized in our hospital from December 2008 to December 2018, and analyze the impact of gender, age, diagnosis time, ducation level, allergen type to the length of stay, hospitalization cost, medical technology diagnosis and treatment costs, western medicine costs, average daily hospitalization costs and other indicators. Results: The average length of hospitalization for occupational asthma patients was (38.7±8.1) days, and the average hospitalization cost was 14743 yuan, of which medical technology diagnosis and treatment costs, western medicine costs, and comprehensive medical service costs accounted for the top three, 42.5% (331977/781369) , 32.0% (249942/781369) , 19.6% (153268/781369) respectively. Hospitalization days for occupational asthma patients has decreased significantly in 2014-2018 (P<0.05) . There were no significant differences in hospitalization costs, medical technology diagnosis and treatment costs, western medicine costs, and average daily hospitalization costs for occupational asthma patients caused by different allergens (isocyanates, persulfates and phthalic anhydrides) (P>0.05) . Hospitalization days, hospitalization costs, medical technology diagnosis and treatment costs, western medicine costs, and average daily hospitalization costs of patients with moderate occupational asthma were significantly higher than those of mild patients (P<0.05) . Conclusion: Early detection of occupational asthma patients and early intervention can reduce the economic burden on patients and society.

Strain-induced indirect-to-direct bandgap transition in an np-type LaAlO3/SrTiO3(110) superlattice.

Using first-principles calculations, we studied the influence of in-plane strain on the electronic properties of the polar LaAlO3/SrTiO3 (LAO/STO)(110) superlattice. We propose that alternate positively (n-type) and negatively (p-type) charged interfaces can be introduced along the [110] direction, without changing the stoichiometry of the system, if the np-type LAO/STO(001) superlattice is constructed in a 45° stepped pattern. We find that when the LAO-STO layer thickness is larger than the critical thickness of the insulator-metal transition, a quasi-two dimensional hole gas and an anisotropic quasi-two dimensional electron gas are formed at alternate interfaces. By applying uniaxial in-plane strains, an unexpected indirect-to-direct bandgap transition occurs in the polar LAO/STO(110) superlattices. The strain-induced changes in the O-2p orbitals near the p-type interface modify the dispersion of valence-band edges, leading to the transition.

[Characteristics of auditory brainstom response and auditory steady state evoked responses in noise-induced hearing loss population].

Objective: To explore the characteristics of auditory steady state evoked responses (ASSR) and auditory brainstem response (ABR) in noise-induced hearing loss population and the relationship between the response threshold of corresponding frequency and pure tone audiometry (PTA) . Methods: Noise-induced hearing loss patients who completed subjective and objective audiometry in our hospital from October 2014 to October 2018 were collected. The results of PTA, ABR, ASSR and the correlation between subjective and objective audiometry were discussed. Results: A total of 381 ears of 193 patients were enrolled. The difference of 0.5, 1.0, 2.0 and 4.0 kHz between ASSR threshold and PTA was 5.9, 6.9, 11.8 and 1.8 dB, respectively. The correlation coefficients were 0.638, 0.680, 0.657 and 0.608. The difference of 1.0, 2.0, 3.0 and 4.0 kHz between ABR threshold and PTA was 44.2, 35.0, 19.0 and 2.0 dB. With the increase of frequency, the threshold difference between ABRt V wave and PTA decreased gradually. Conclusion: ASSR and ABR response thresholds are valuable in subjective assessment on noise-induced hearing loss. The thresholds of ASSR and ABR at 4 kHz are close to those of PTA.

[Evaluating the level of occupational stress and its influence factors among traffic police in a district in Shanghai].

Objective: To investigate the high occupational stress and its influencing factors in traffic police in Shanghai. Methods: 728 traffic police were selected as the study subjects, and the《Occupational Health Questionnaire》was used to investigate and evaluate their job demand-control (JDC) and effort-reward imbalance model (ERI) occupational stress situation respectively. The related influencing factors were analyzed. Results: The prevalence rates of high occupational stress in JDC and ERI models were 74.6% (543/728) and 51.5% (375/728) . The influencing factors of JDC were education, marriage, average weekly hours (χ(2)=16.82, 10.04, 18.71, P<0.05) , and The influencing factors of ERI were gender, age, marriage, real monthly income level, education, work experience, and average weekly hours (χ(2)=7.02, 26.18, 6.73, 50.42, 4.75, 26.61, 112.98, 6.19, P<0.05) . The JDC multivariate logistic analysis indicated that the risk of occupational stress of married police was 2.81 times as high as that of Unmarried ones. The risk of occupational stress of traffic police with more education was 1.92 times as high as that of low eduacation, average weekly working 41-50 hours and≥51 hours was 2.53, 3.12 times as high as that of ones with average working 40 hours, respectivly. Meanwhile, the ERI multivariate logistic analysis indicated that high income level is the protective factor of occupational stress. The traffic police with 15-<20 working years were more likely to occur higher occupational stress. The traffic police with the more average weekly hours had greater possibility of higher occupational stress. Conclusion: The main influencing factors of JDC and ERI are marriage, real monthly income level, education, work experience, and average weekly hours.

[Occupational characteristics of 318 cases diagnosed as occupational asthma].

Objective: To summarize the clinical characteristics of occupational asthma and provide a basis for revising the diagnosis of occupational asthma in China. Methods: Taking "occupational asthma" , "occupational bronchial asthma" and "bronchial provocation test at work site" as key words, the case reports of occupational asthma in China were retrieved. The general data, latent period, allergen, clinical manifestation, and diagnostic methods were analyzed. Results: A total 318 cases from 14 published literatures were reported.The incidence of male and female is basically similar. The average age of onset is 38 years, and the latent period is from 2 months to 19 years. The top 3 allergens were isocyanates, penicillin and cephalosporins, formaldehyde. During the diagnosis process, 48.8% of the patients were diagnosed by bronchial provocation test, and 19 cases were diagnosed according to the specific IgE antibody. Only 1 case was diagnosed according to the specific skin test. Conclusion: The etiological diagnosis of occupational asthma is not easy. Nearly half of the patients in our country have been diagnosed as occupational asthma by bronchial provocation test at work site. How to identify the relationship between occupational exposure and the occurrence of asthma is one of the main problems we need to solve.

[Study on airway inflammation in patients with occupational pulmonary thesaurosis induced by iron].

Objective: To study the airway inflammation feature difference in the patients with occupational pulmonary thesaurosis induced by iron. Methods: Induced sputum samples were obtained from 20 healthy men, 20 patients with stable asthma, 25 patients with occupational pulmonary thesaurosis induced by iron. Differential cell counts in induced sputum were examined. The levels of supernatant IL-8 were measured by ELISA. Results: The pulmonary function result was normal in the patients with pulmonary thesaurosis., their FVC (4.1±1.2) L was similar to FVC (4.3±0.9) L in mal group; but their FEV(1.0) (2.9±0.9) L、FEV(1)/FVC (71.9%±5.4%) were lower than normal group's FEV(1.0) (3.2±0.7 L) 、FEV(1.0)/FVC (79.2%±9.9%) , and were hirher than asthma group's FEV(1) (2.5±0.8) L and FEV(1.0)/FVC (68.7%±6.1%) . In induced sputum, macrophages percentage in patients with pulmonary thesaurosis (54.3%±9.7%) was higher than asthma group and normal group (48.4±6.4, 51.9±7.3, P<0.05) , neutrophils percentage in patients with pulmonary thesaurosis group (43.9%±7.6%) was higher than asthma group and normal group (41.3%±7.1%, 39.8%±6.9%, P<0.05) , eosinophils percentage in patients with pulmonary thesaurosis group (0.3%±0.1%) was lower than asthma group (2.8±0.3, P<0.05) , lymphocytes percentage in patients with pulmonary thesaurosis group (2.0%±0.4%) was lower than asthma group (4.7±0.6, P<0.05) ; the sputum levels of IL-8 in patients with pulmonary thesaurosis group (914.7±24.3) pg/ml was higher than asthma group and normal group (747.9%±16.8 pg/ml, (405.4±13.7) pg/ml, P<0.05) . Conclusion: Macrophages and IL-8 may play an important role in the pathogenesis of airway inflammation after long-term inhalation of iron and its compounds, the airway function in patients of occupational pulmonary thesaurosis was found damaged.

[Comparison of whole blood indium and the serum indium of the population exposed to the indium].

Objective: The method was established for the detection of whole blood indium and serum indium. By comparing the results of two samples, it is possible to explore the significance of whole blood indium and serum indium in the population exposed to indium compounds. Methods: According to GBZ/T 295-2017 and GBZ 294-2017, the whole blood and serum samples were diluted 20 times by 0.5% nitric acid solution (including 0.05% Triton X-100) . Under the standard mode of inductively coupled plasma mass spectrometry (ICP-MS) , whole blood indium and serum indium of indirect exposure group, low exposure group and high exposure group in an indium mine were detected with 20 µg/L rhodium standard solution as internal standard. Results: This method has a working range of 0.00~5.00 µg/L and a correlation coefficien t>0.999. The detection limit and quantitative lower limit of whole blood indium were 0.076 µg/L and 0.26 µg/L respectively. Those of serum indium were 0.06 µg/L and 0.20 µg/L accordingly. The recovery rates of serum and whole blood samples were 88.5%~95.6% and 93.0%~101%. Intra batch precisions were 1.3%~4.4% and 1.9%~3.5% and inter batch precision were 2.4%~6.1% and 2.1%~4.6% in two samples. There were no significant differences between whole blood indium and serum indium in indirect exposure group. The serum indium level was lower than the detection limit in 3 cases, while their whole blood indium was only below the quantitative lower limit. However, in other groups whole blood indium level was significantly higher than serum indium level (P<0.05) and even was two-fold in the high exposure group. Conclusion: The detection of whole blood indium is more sensitive than that of serum indium, which can reflect the internal exposure level more accurately in exposure population. Therefore, the whole blood indium is of more important referential value to health examination and poisoning diagnosis in the population exposed to indium and its compounds.

[Effect of nerve growth factor on chronic peripheral neuropathy in rats induced by 1-bromopropane].

Objective: To observe the effect of nerve growth factor (NGF) and Mecobalamin on chronic peripheral neuropathy in rats induced by 1-bromopropane. Methods: 36 male SD rats were exposed to 1-bromopropane vapor at concentrations of 4 000 mg/m(3), 6 hours per day, 5 days per week for 12 weeks. The rats were randomed divided into 4 groups, and treated by Mecobalamin for 300 µg/kg qd, NGF for 40 µg/kg qd, Mecobalamin+NGF with the dose as mentioned above, respecively. The control group were fed in normal condition. The changes of Sciatic nerve conduction velocity (NCV) , electromyography (EMG) and pathology were observed 30 days later. Results: The nerve conduction velocity were decreased in all the rats. Compared with the control group, the motor nerve conduction velocity (MCV) was improved in group Mecobalamin and group Mecobalamin+NGF, The difference was statistically significant, as the sensory nerve conduction velocity (SCV) was improved only in group Mecobalamin+NGF. Sciatic nerve biopsy observed by electron microscope showed that myelinated nerve fibers were obvious swelling, lamellar separation, partial myelin vacuolization, and axonal degeneration. After treatment with exogenous nerve growth factor, the number and severity of damaged nerve fibers were restored. Conclusion: Exogenous nerve growth factor contributes to the recovery of peripheral nerve damage induced by 1-bromopropane.