Mediating role of psychological capital between occupational stress and depressive symptoms in disease prevention and control personnel / 环境与职业医学

Background Occupational stress and depressive symptoms of disease prevention and control personnel are serious. Objective To investigate the relationship between occupational stress, psychological capital, and depressive symptoms of disease prevention and control personnel, and analyze the potential mediating effect of psychological capital on the relationship between occupational stress and depressive symptoms. Methods From July to September 2020, a cluster random sampling method was used to select 2201 employees from 21 centers for disease control and prevention as study subjects covering all levels of administrative divisions in Jiangsu Province. A total of 2036 valid questionnaires were collected with a recovery rate of 92.5%. The Core Occupational Stress Scale, Patient Health Questionnaire, and Psychological Capital Questionnaire were used to investigate their occupational stress, depressive symptoms, and psychological capital. Stratified regression analysis was used to explore the effects of occupational stress and psychological capital on depressive symptoms. A mediating effect model was used to analyze and verify the potential mediating effect of psychological capital on the relationship between occupational stress and depressive symptoms. Results The total scores in M (P25, P75) of occupational stress, depressive symptoms, and psychological capital in the target population were 42.0 (37.0, 48.0), 8.0 (4.0, 9.0), and 4.6 (4.0, 5.0) respectively. The positive rate of occupational stress was 31.0% (631/2036), and the positive rate of depressive symptoms was 22.0% (448/2036). The dimensional scores of organization and reward, and demand and effort of occupational stress were positively correlated with the total score of depressive symptoms [Spearman correlation coefficients (rs) were 0.371 and 0.269, P<0.05]. The dimensional scores of social support and autonomy of occupational stress and the score of psychological capital were negatively correlated with the total score of depressive symptoms (rs=−0.373, −0.112, −0.494, P<0.05). The organization and reward, and demand and effort had positive effects on depressive symptoms (b=0.188, 0.177, P<0.05), while social support and autonomy had negative effects on depressive symptoms (b=−0.290, −0.078, P<0.05), and associated with a 22.5% increase of explanatory variance. Psychological capital had a negative effect on depressive symptoms (b=−0.368, P<0.05), and associated with an 11.0% increase of explanatory variance. Psychological capital had mediating effects on the associations of social support, organization and reward, and autonomy with depressive symptoms, and the mediating effect values were −0.210 (95%CI: −0.253-−0.171), 0.096 (95%CI: 0.071-0.122), and −0.164 (95%CI: −0.229-−0.103), respectively. The corresponding mediating effect percentages were 40.23%, 26.97%, and 45.56%, respectively. Conclusion Occupational stress of disease prevention and control personnel can directly affect depressive symptoms, but also indirectly through psychological capital. Psychological capital plays a partial mediating role in the associations of social support, organization and reward, and autonomy of occupational stress with depressive symptoms. The occurrence of depressive symptoms can be reduced by decreasing occupational stress and increasing psychological capital.

Role and mechanism of IGF2BP3 in malignant transformation of human gastric epithelial cells induced by MNNG / 环境与职业医学

Background N6-methyladenosine (m6A) RNA methylation may play an important role in the process of malignant transformation of cells induced by environmental carcinogens. However, the specific roles and mechanisms need to be further explored. Objective To explore the role and mechanism of m6A binding protein insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) in the malignant transformation of human gastric mucosal epithelial cells GES-1 induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Methods Based on the GES-1 malignant transformation cells MC-30, a stable knockdown IGF2BP3 MC-30 cell line (MC30-shIGF2BP3, abbreviated as MC30-shI3) was constructed by lentiviral transfection technology, and a negative control group (MC30-NC) was also prepared. Real-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting were applied to detect the mRNA expression and protein levels of IGF2BP3. RNA binding protein immunoprecipitation (RIP-qPCR) was used to examine the combination between IGF2BP3 protein and MYC mRNA in malignant cells MC-30. Furthermore, the stability of MYC mRNA was detected by actinomycin D assay. CCK-8 and Transwell respectively were employed to detect cell proliferation, migration, and invasion. Western blotting was applied to detect the expression of EMT markers (N-cadherin, Vimentin, α-SMA, and Snail). The role of the downstream target gene MYC was further elucidated by a rescue assay in MC30-shI3 cells transfected with a plasmid overexpressing MYC to observe changes in cellular phenotypes (proliferation, migration, invasion) and expression of key EMT proteins. Results Compared with the control group, the expression of IGF2BP3 mRNA was up-regulated after 5, 10, 20, and 40 μmol·L−1 MNNG infection of GES-1 cells (P<0.05). After 20 μmol·L−1 MNNG infection, the expression level of IGF2BP3 mRNA increased with prolongation of exposure time (P<0.05). Compared with the control group, the mRNA and protein expression levels of IGF2BP3 were up-regulated in the 10th, 20th, and 30th generations of 5 μmol·L−1 MNNG malignant transformation (P<0.05). The results of qRT-PCR and Western blotting showed that, compared with the MC30-NC group, the IGF2BP3 and MYC mRNA expression and protein expression decreased in the MC30-shI3 group (P<0.01). The CCK8 and transwell assay results showed that, compared with the MC30-NC group, the cell proliferation, migration, and invasion abilities significantly reduced in the MC30-shI3 group (P<0.01). The results of the Western blotting showed that, compared with the MC30-NC group, the protein levels of EMT markers N-cadherin, Vimentin, α-SMA, and Snail decreased in the MC30-shI3 group (P<0.01). The results of RIP-qPCR showed that, compared with the IgG group, the mRNA level was higher for the enriched MYC in the IGF2BP3 group (P<0.01); the results of the actinomycin D assay showed that, compared with the MC30-NC group, the stability of MYC mRNA significantly reduced in the MC30-shI3 group (P<0.01). While the rescue experiment showed that, compared with the IGF2BP3 knock-down+vector group, the MYC protein level significantly increased in the IGF2BP3 knock-down + MYC over-expression group (P<0.01), the proliferation, migration, and invasion abilities significantly enhanced (P<0.01), and the EMT key proteins (N-cadherin, Vimentin, α-SMA, Snail) increased in the MC30-shI3+MYC group (P<0.01). Conclusion Exposure to MNNG could result in up-regulation of IGF2BP3 expression in GES-1 cells. IGF2BP3 may enhance the proliferation, migration, and invasion of malignantly transformed human gastric epithelial cells by binding to MYC mRNA and increasing its stability and expression level and thus promoting the EMT process, which in turn affects the progression of malignant transformation.

Occupational hazards and risk assessment of benzene-related enterprises in yangzhou city from 2014 to 2018 / 中华劳动卫生职业病杂志

Objective@#To investigate the benzene concentration in the workplace of benzene-related enterprises in Yangzhou City from 2014 to 2018, and the abnormal blood routine of workers exposed to benzene, and to assess their occupational hazards.@*Methods@#The environmental monitoring data of benzene-related enterprises and the health examination data of benzene exposed workers were collected in March 2019. The inhalation risk assessment model of the National Environmental Protection Agency (EPA) was used to assess the carcinogenic and non-carcinogenic risks of benzene workers.@*Results@#The qualified rate of benzene detection in the workplace was 100% from 2014 to 2018, the highest concentration was 1.42 mg/m3 in five years. The abnormal rates of blood routine detection in benzene exposed workers in five years was 7.10% (213/2 998) 、5.17% (218/4 214) 、5.61% (196/3 493) 、7.65% (288/3 767) 、7.83% (280/3 574) and 7.83%. respectively. The results of risk assessment showed that the minimum carcinogenic risk value was 7.56×10-6 and the maximum carcinogenic risk value was 31.33×10-6 in 2014-2018. The hazard quotient values were than 1.@*Conclusion@#Benzene monitoring concentration in benzene-related enterprises in Yangzhou City from 2014 to 2018 was low, which meets the occupational exposure limit in China. However, the abnormal rate of blood routine in five years is still high, and there are both carcinogenic and non-carcinogenic risks. We should pay more attention to the health risk of workers exposed to low concentrat in benzene.

miR-93-5p Transferred by Exosomes Promotes the Proliferation of Esophageal Cancer Cells via Intercellular Communication by Targeting PTEN / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the relationship between plasma miR-93-5p and the risk of esophageal cancer, as well as the influence of miR-93-5p on the biological function of esophageal cancer cells, exerted through exosomes.</p><p><b>METHODS</b>The expression of plasma miR-93-5p in esophageal cancer patients and healthy controls was analysed by real-time quantitative PCR. The influence of miR-93-5p on the risk and prognosis of esophageal carcinoma was analyzed by conditional logistic regression and survival analysis. The effect of miR-93-5p on the biological function of recipient cells was investigated by establishing an in vitro donor cell co-culture model. The target gene of miR-93-5p was validated by luciferase reporter assay and Western Blotting.</p><p><b>RESULTS</b>Upregulation of plasma miR-93-5p expression significantly increases the risk of esophageal cancer and is associated with poor prognosis. miR-93-5p transferred by exosomes promotes the proliferation of recipient esophageal cancer cells and affects the expression of PTEN and its downstream proteins p21 and cyclin D1.</p><p><b>CONCLUSION</b>Our study provides a reference for the identification of biomarkers for the diagnosis and prognosis of esophageal cancer.</p>

Prevalence of Overweight and Obesity among Students Aged 7-22 Years in Jiangsu Province, China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To report the prevalence and trend of overweight and obesity among students aged 7-22 years in Jiangsu, 2010 to 2013.</p><p><b>METHODS</b>This cross-sectional study was carried out as part of students physical fitness and health survey in Jiangsu province. A total of 255,581 subjects (50.03% males and 49.97% females) enrolled in 82 school and 10 universities in Jiangsu. Weights and heights were obtained for each subject and its body mass index (BMI) was calculated using the Chinese Working Group on Obesity in China (CWGO).</p><p><b>RESULTS</b>Anthropometric measurement including bodyweight, height, BMI and bust were significantly different between males in urban compared to females living rural areas (P<0.001). The total prevalence of overweight and obesity was 12.4% and 5.7%. Males had a significantly higher rate than in female's student. The prevalence of overweight and obesity by age groups was (14.5%, 10.3%) at age 7-11 years, (11.2%, 6.8%) at age 12-14 years, (11.7%, 3.1%) at age 15-17 years, and (11.4%, 2.3%) at age 18-22 years. By regions; the highest prevalence of overweight obesity reported in Taizhou (10%, 14.2%), Xuzhou (9.4%, 12.5%), and Nanjing (9.2%, 15.6%), respectively.</p><p><b>CONCLUSION</b>The finding declares that overweight and obesity are important health problems among students in Jiangsu Province. Early intervention programme are needed to address this problems.</p>

Isolation and characterization of an algicidal bacterium indigenous to lake Taihu with a red pigment able to lyse microcystis aeruginosa / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To isolate and characterize indigenous algicidal bacteria and their algae-lysing compounds active against Microcystis aeruginosa, strains TH1, TH2, and FACHB 905.</p><p><b>METHODS</b>The bacteria were identified using the Biolog automated microbial identification system and 16S rDNA sequence analysis. The algae-lysing compounds were isolated and purified by silica gel column chromatography and reverse-phase high performance liquid chromatography. Their structures were confirmed by Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FT-IR) spectroscopy. Algae-lysing activity was observed using microscopy.</p><p><b>RESULTS</b>The algae-lysing bacterium LTH-2 isolated from Lake Taihu was identified as Serratia marcescens. Strain LTH-2 secreted a red pigment identified as prodigiosin (C20H25N3O), which showed strong lytic activity with algal strains M. aeruginosa TH1, TH2, and FACHB 905 in a concentration-dependent manner. The 50% inhibitory concentration (IC50) of prodigiosin with the algal strains was 4.8 (± 0.4)× 10⁻² μg/mL, 8.9 (± 1.1)× 10⁻² μg/mL, and 1.7 (± 0.1)× 10⁻¹ μg/mL in 24 h, respectively.</p><p><b>CONCLUSION</b>The bacterium LTH-2 and its pigment had strong Microcystis-lysing activity probably related to damage of cell membranes. The bacterium LTH-2 and its red pigment are potentially useful for regulating blooms of harmful M. aeruginosa.</p>

ZnO, TiO(2), SiO(2,) and Al(2)O(3) nanoparticles-induced toxic effects on human fetal lung fibroblasts / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>This study aims to investigate and compare the toxic effects of four types of metal oxide (ZnO, TiO(2), SiO(2,) and Al(2)O(3)) nanoparticles with similar primary size (∼20 nm) on human fetal lung fibroblasts (HFL1) in vitro.</p><p><b>METHODS</b>The HFL1 cells were exposed to the nanoparticles, and toxic effects were analyzed by using MTT assay, cellular morphology observation and Hoechst 33 258 staining.</p><p><b>RESULTS</b>The results show that the four types of metal oxide nanoparticles lead to cellular mitochondrial dysfunction, morphological modifications and apoptosis at the concentration range of 0.25-1.50 mg/mL and the toxic effects are obviously displayed in dose-dependent manner. ZnO is the most toxic nanomaterials followed by TiO(2), SiO(2), and Al(2)O(3) nanoparticles in a descending order.</p><p><b>CONCLUSION</b>The results highlight the differential cytotoxicity associated with exposure to ZnO, TiO(2), SiO(2), and Al(2)O(3) nanoparticles, and suggest an extreme attention to safety utilization of these nanomaterials.</p>

Detection of CYP2E1, a genetic biomarker of susceptibility to benzene metabolism toxicity in immortal human lymphocytes derived from the Han Chinese Population / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Cytochrome P450 2E1 (CYP2E1) is an important metabolizing enzyme involved in oxidative stress responses to benzene, a chemical associated with bone marrow toxicity and leukemia. We aimed to identify the CYP2E1 genetic biomarkers of susceptibility to benzene toxicity in support of environmental and occupational exposure prevention, and to test whether a model using immortal human lymphocytes might be an efficient tool for detecting genetic biomarkers.</p><p><b>METHODS</b>Immortalized human lymphocyte cell lines with independent genotypes on four CYP2E1 SNP sites were induced with 0.01% phenol, a metabolite of benzene. CYP2E1 gene function was evaluated by mRNA expression and enzyme activity. DNA damage was measured by Single-Cell Gel Electrophoresis (SCGE).</p><p><b>RESULTS</b>Among the four SNPs, cells with rs2070673TT and rs2030920CC showed higher levels of CYP2E1 transcription and enzymatic activity than the other genotypes in the same SNP site. Cells with higher gene expression genotypes also showed higher comet rates compared with lower gene expression genotypes.</p><p><b>CONCLUSION</b>These results suggest that CYP2E1 rs2070673 and rs2030920 might be the genetic biomarkers of susceptibility to benzene toxicity and that the immortalized human lymphocytes model might be an efficient tool for the detection of genetic biomarkers of susceptibility to chemicals.</p>

Association of combined CYP2E1 gene polymorphism with the risk for esophageal squamous cell carcinoma in Huai'an population, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cytochrome P450 2E1 (CYP2E1) has an important role in the metabolic activation of precarcinogens such as N-nitrosoamines and other low relative molecular mass, organic compounds. This study examined whether CYP2E1 RsaI and DraI polymorphism are associated with susceptibility to esophageal squamous cell carcinoma and the correlation between the genotypes and expression levels of CYP2E1 mRNA.</p><p><b>METHODS</b>Seventy-seven patients with newly diagnosed, untreated esophageal squamous cell carcinoma and 79 healthy controls matched in age, gender and residence were recruited for the control study. An RsaI polymorphism in the 5'-flanking region and a DraI polymorphism in the sixth intron of the CYP2E1 gene, which could possibly affect its transcription, were determined in this study by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and mRNA level of CYP2E1 was measured by quantitative real-time reverse transcription PCR.</p><p><b>RESULTS</b>No significant association of RsaI or DraI polymorphism of CYP2E1 with susceptibility of esophageal squamous cell carcinoma were demonstrated (OR = 1.67, 95% CI: 0.89 - 3.15, P = 0.11; OR = 1.11, 95% CI: 0.59 - 2.09, P = 0.74, respectively). With SHEsis software, no linkage disequilibrium was detected between RsaI and DraI polymorphism (D' = 0.528, r(2) = 0.27). When combined RsaI polymorphism with DraI polymorphism, the association between that carrying c2 allele and DD genotype and the risk for esophageal squamous cell carcinoma were found (OR = 5.77, 95% CI: 1.65 - 20.22). Compared with the normal controls, the mRNA levels with RsaI polymorphism, DraI polymorphism, or any combined genotypes in cases showed no statistical difference.</p><p><b>CONCLUSIONS</b>This study suggests that carrying c2 allele and DD genotype conferreded an elevated risk for esophageal squamous cell carcinoma. There was no significant statistical relationship between the genotypes c1/c2, D/C, or the combined allele and mRNA expression.</p>

In vivo degradation and tissue compatibility of poly-L-lactide/beta-tricalcium phosphate composite rods for internal fixation of bone fractures / 生物医学工程学杂志

Abstract Poly-l-lactide/beta-tricalcium phosphate (PLLA/betaTCP) composite was obtained by combining ground beta-TCP with PLLA, and absorbable rods were prepared by injection moulding. Degradations of the rods were investigated by scanning electron microscope (SEM), mass loss, molecular weight and bending strength changes. At the beginning of in vivo degradation of the rods, the molecular weight of PLLA decreases sharply with the less mass losses of the rods. As in vivo degradation progress, the surfaces of the rods changed roughly, while micropores and fine groove were observed in the inner part of the rods. The bending strength of composite rods decreased from 151 MPa to 106 MPa after in vivo degradation of 12 weeks. Tissue test reveal that PLLA/beta-TCP composite has good tissue compatibility compared with PLLA.

Relationship between quinone oxidoreductase1 gene ns-cSNP and genetic susceptibility of esophageal cancer / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the relationship between quinone oxidoreductase1 (NQO1) gene nonsynonymous cSNP and the genetic susceptibility of esophageal cancer.</p><p><b>METHODS</b>Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and Allele-Specific PCR (AS-PCR) were employed to assess the polymorphism of NQO1 genes both in 106 patients with esophageal cancer and control subjects matched by age, gender and origin.</p><p><b>RESULTS</b>It was shown that no C/C genotype was found at 406 of NQO1. The allelic frequency of NQO1 609T was significantly higher in patients with esophageal cancer than in the control subjects (P < 0.005) and the individuals with 609T allelic genotype of NQO1 gene were at greater risk to develop esophageal cancer (OR = 4.76, 95% CI = 1.064 - 3.397). But Individuals with mutant allele of NQO1 465 genotype did not show the rising risk of esophageal cancer.</p><p><b>CONCLUSIONS</b>The NQO1 C609T polymorphisms should likely be associated with the genetic susceptibility of esophageal cancer.</p>

Study on hydroxyapatite porous scaffold bonded by phosphates and its biocompatibility / 生物医学工程学杂志

The porous scaffolds for bone tissue engineering were prepared by foam impregnation. The magnesium and aluminum acid phosphates were used as bonder and the hydroxyapatite ((Ca10 (PO4)6(OH)2, HA) powder as raw materials. Scanning electron microscopy (SEM) examination indicated that the 3D interconnected porous structure of the organic foam was replicated well by the scaffolds calcined at high temperature and the structural requirement of tissue engineering was satisfied. XRD analysis showed that the scaffold was composed of HA and Ca7Mg2P6O24 while calcined at 1150 degrees C for shorter time and of (Ca, Mg)3(PO4)2 when the time prolonged to 2 h. There was no peak of CaO found in the scaffolds by XRD. According to the culture in vitro, the scaffold possesses good biocompatibility and certain degree of degradability.

A study on the repair of bone defects with deproteinized bone surrounded by titanium mesh and osteoblasts / 生物医学工程学杂志

To investigate the ability of composite graft of osteobalsts and deproteinized bone-titanium mesh (DPB-TM) scaffold to repair cranial bone defect. 30 rabbits were randomly divided into 3 groups. The passage 3 fetal rabbit osteoblasts were seeded into porous DPB-TM scaffolds at the density of 5 x 10(6) ml(-1) as the experimental group. The same defects were respectively reconstructed by DPB-TM or osteoblasts as the control groups. After 12 weeks, the result was evaluated by three-dimensional computed tomographic scanning, gross inspection, scanning electron microscopy, histological examination and mechanics test, respectively. In the experimental group, bone trabecula was observed to pass the defect and interface was mixed. No demarcation between the region of the bone defect and the normal bone was observed. There was plenty of new bone on the scaffold. Part of the scaffold was absorbed. In view of mechanics, the intensity of artificial bone (18.93+/-1.12 MPa) was higher than that of normal bone (16.96+/-1.60 MPa) (P<0.05). In the control groups, only fibrous tissue was observed in the defect region, there was no new bone formation. The tissue engineering bone constructed by osteoblasts and DPB-TM scaffold can be applied to the repair of bone defect.

Observation of the grafting of platelet-derived growth factor gene-modified artificial composite skin on rat wounds / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the effects of the grafting of a platelet-derived growth factor gene-modified artificial composite skin on rat wounds with full thickness defect.</p><p><b>METHODS</b>Platelet derived growth factor-B (PDGF-B) eukaryotic expression plasmid was constructed, and the fibroblasts were transfected with it by liposome mediation. Artificial composite skins 1 and 2 were constructed respectively. The skin1 was composed of keratinocyte, porcine acellular dermal matrix and PDGF-B gene-transfected fibroblasts while the skin 2 contained keratinocyte, porcine acellular dermal matrix and fibroblasts. The two kinds of composite skin were grafted onto wounds on the rat back to form composite skin group 1 (C1) and 2 (C2), respectively, with 18 rats in each group. Eight rats with wounds without treatment served as control (C) group. The survival rate of the composite skin was observed at 2 post-operative weeks (POWs). The rat wounds were examined grossly on 2, 4 and 6 POWs for the calculation of wound contraction rate. Wound tissue samples were harvested for histological examination.</p><p><b>RESULTS</b>(1) Up to 2 POWs, 14 grafts in C1 group survived completely, 3 with partial survival and 1 failure. In C2 group, 10 skin grafts survived completely, 4 with partial survival and 4 failures. (2) A scab was formed in the wound at 2 POW in C group. The surface of the grafted skin in C1 group was smooth, elastic, and showed good anti-friction properly, and it was better in quality compared with that in other two groups at 6 POW. (3) The wound contraction rate of the grafts in C group of rats was higher than that in C1 and C2 groups at 2, 4 and 6 POWs, while that in C1 was lower than that in C2 group. (4) Capillary formation was more intense in the grafted skins in C1 group at 2 POWs, and the epithelia differentiated well into 7 to 10 layers of epithelial cells with compact and orderly arrangement and evenly distributed fibrous tissue at 6 POWs.</p><p><b>CONCLUSION</b>Repair of the wound with artificial composite skin containing PDGF-B gene could improve the quality of wound healing.</p>

Cytotoxicity of Oxidation Hair Dyes on Rat's Keratinocytes / 环境与健康杂志

Objective To explore the mechanism of the skin lesion induced by oxidation hair dyes Methods The effects of subjects,such as oxidation hair dyes,hydrogen peroxide (H 2O 2) and p phenylenediamine (PPD) and their mixture which were main components of oxidation hair dyes,on the proliferation of rat's keratinocytes were detected by primary culture technique of rat's keratinocytes and MTT colorimetric assay Results All of the observed groups presented a certain inhibition on proliferation of the rat's keratinocytes,except the group exposed to PPD at the lowest dose for the shorter period The OD values decreased with the increase of exposure levels and periods Dose response relationship was observed between the exposure levels and inhibition rates of cell survival(the r values after 24 h exposue: r H 2O 2 =0 981, r PPD =0 949, r PPD-H 2O 2 =0 963, r hair dyes =0 887) Conclusion The skin lesion induced by oxidation hair dyes might associated with its cytotoxicity

The Oxidative Stress Way Induced by Soot on Rat Pulmonary Cells / 环境与健康杂志

ve To study the way of oxidative stress induced by soot rat pulmonary cells type Ⅱ ?Methods Before exposure to soot extracts, the rat pulmonary cells were pretreated with anti-oxidative agent, N-acetylcysteine (NAC), vitamin C, vitamin E and mannitol for 30 minutes, then the ceils were exposed to the soot extracts for 24 hours. MTT assay was applied to detect the cytotoxicity. Results It showed that NAC, vitamin C and vitamin E could reduce the cytotoxicity of rat pulmonary cell caused by soot, but no same change was observed in that of man-nitol. Conclusion It was suggested that the DNA oxidative stress of soot may be caused by multi-ways, such as in-duction of oxygen free radical and lipid peroxide etc.

Micronucleus Test of Mice Peripheral Blood Reticulocytes Induced by Organic Extracts of Air Particulate Pollutants in Railway Transport Station of Chemical Dangerous Goods / 环境与健康杂志

Objective To investigate the micronucleus frequency in mice peripheral blood reticulocytes induced by air particulate pollutants in a railway transport station of chemical dangerous goods (RTSCDG) Methods Male BALB/C mice were selected and randomly divided into exposure groups and control groups One time exposure experiment was carried out among mice exposed to acetone extracts of air particulate pollutants at doses of 20,40,80,160 mg/kg by intraperitoneal injection Multiple time exposure experiment was carried out among mice exposed to acetone extacts of air particulate pollutants at dose of 10 mg/kg by consecutive intraperitoneal injection one time per day for 5 days The peripheral blood was sampled from mice tails and the micronucleus frequencies in reticulocytes were observed at 24, 48 and 72 h after the exposure Results The frequencies of micronuclei in peripheral blood reticulocytes revealed good time response relationship and reached the highest levels at 48 h after exposure,at the same time the frequencies of micronuclei in dose groups of 20,40,80,160 mg/kg were all higher than those in control group The multiple frequencies exposure experiment with lower dose showed that the frequencies of micronuclei in peripheral blood reticulocytes in exposure group always revealed significantly higher levels compared with those in control group during the 24th~72th hour after the exposure ( P