Objective To investigate the virulence role of ompT of Escherichia coli in the patho-genesis of neonatal meningitis .Methods Adhesive abilities of the parent strain E 44 and the isogenic ompT-deletion mutant strain ( E44 ∶ΔompT) to human brain microvascular endothelial cells were evaluated in in vitro model.Low-copy-number plasmid pST containing ompT locus and point mutant plasmid pST 85 were transferred into E44 ∶ΔompT to construct the complemented mutant strain , and its adhesive ability was ana-lyzed.Influences of ompT deletion on E44 strain in its ability of bacterial intestinal colonization and ability of penetrating the blood-brain barrier were determined . Results In comparison with the parent strain , E44 ∶ΔompT strain showed significantly impaired adhesive ability to human brain microvascular endothelial cells, which could be partly restored by inserting the complementary plasmids of pST and pST 85.Deletion of the ompT did not affect Escherichia coli K1 in normal intestinal colonization in in vivo model.E44 ∶ΔompT strain could induce bacteremia , which was similar to that induced by the parent strain , but its ability of crossing the blood-brain barrier was significantly declined .Conclusion The study demonstrate that ompT plays an important role as the virulence element of Escherichia coli in binding to brain microvascular endothe-lial cells and penetrating the blood-brain barrier .Further study should be performed to investigate the influ-ences of OmpT proteinase on the virulence of Escherichia coil.

Objective To study the effect of DNA damage induced by H2 O2 on the micronucleus frequency in lymphocytes. Methods Resting lymphocytes were treated with different levels of H2 O2 (10,50,100,1 000 μmol/L).1 000 μmol/L H2 O2 was added into mitogen-stimulated lymphocyte cultures at different time intervals.Then micronucleus rate was examined by the conven-tional culture method.Results There was no significant change of the micronucleus frequency in the experimental groups.Conclu-sion H2 O2 could induce lymphocyte DNA damage rapidly,but exerts no effect on the formation of micronuclei,which may be relat-ed to the type of DNA damage and rapid DNA repair.

Objective To establish a method for the isolation and identification of platelets.Methods 10 healthy volunteers were selected to collect the EDTA anticoagulant venous blood of 3 tubes,each tube was 2 ml,which was divided into the whole blood cell tube,platelet rich plasma (control group),and stepped centrifugal platelet extract (experiment group).Platelet was isolated by simple centrifugation method(PRP) and stepped centrifugal method.The two groups were full blood count and analyzed by microscopic morphology and platelet activity test.Leukocyte specific HGB gene and platelet mitochondrial ND1 gene content was analyzed by real time PCR.Results Platelets were extracted and detected in control group and experimental group.Platelets were found and white blood cells and red blood cells were not remained in experimental group.Platelets and sporadic white blood cells were found in control group.The platelet pick up rate of experiment group was significantly higher than control group,the difference was statistically significant.Experimental gene content HGB of experiment group was significantly lower than control group,the difference was statistically significant (t=-3.281,-2.865,P＜0.05).ND1 gene content of experiment group higher than the control group,the difference was not statistically significant.There was no significant difference for platelet activity test between experimental group and control group (t=-0.046,-0.799,P＞ 0.05).Conclusion A isolation and identification method of stepped centrifugal platelet was established.The method can be used for the study of platelet gene and the functional analysis of platelets.

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.

Objective:To research the mitochondrial cytochrome c oxidase subunit I (MT-COI) gene methylation levels in patients with occupational chronic benzene poisoning, and to explore effective molec μlar biomarkers in patients with occupational chronic benzene poisoning.Methods:38 confirmed cases of occupational chronic benzene poisoning were selected in the case group. 46 healthy people who underwent physical in our hospital were selected in the control group. Pyrosequencing was used to detect the methylation sites of methylation sites, flow cytometry was used to detect peripheral blood cell count levels, and non-parametric statistical methods were used to analyze the differences in detection results between the two groups.Results:The methylation level of mitochondrial MT-COI site 1 (2.21±0.81) % in the case group was less than that in the control group, and the difference was statistically significant ( P<0.05) . The methylation level of mitochondrial MT-COI site 2 (2.31±0.96%) in the case group was less than that in the control group, and the difference was statistically significant ( P<0.05) . The methylation average level of mitochondrial MT-COI (2.26±0.75) % in the case group was less than that in the control group, and the difference was statistically significant ( P<0.05) . Analysis of the average level of methylation found that the methylation level of mitochondrial MT-COI was correlated with WBC ( P<0.05) . Analysis of the average level of methylation found that the methylation level of mitochondrial MT-COI was correlated with platelets ( r=0.254、0.280, P<0.05) . Conclusion:The level of mitochondrial MT-COI gene methylation in patients with occupational chronic benzene poisoning may be related to the sensitivity to benzene exposure. Mitochondrial MT-COI gene methylation may serve as a potential predictive biomarker for benzene poisoning.

Objective:To research the mitochondrial cytochrome c oxidase subunit I (MT-COI) gene methylation levels in patients with occupational chronic benzene poisoning, and to explore effective molec μlar biomarkers in patients with occupational chronic benzene poisoning.Methods:38 confirmed cases of occupational chronic benzene poisoning were selected in the case group. 46 healthy people who underwent physical in our hospital were selected in the control group. Pyrosequencing was used to detect the methylation sites of methylation sites, flow cytometry was used to detect peripheral blood cell count levels, and non-parametric statistical methods were used to analyze the differences in detection results between the two groups.Results:The methylation level of mitochondrial MT-COI site 1 (2.21±0.81) % in the case group was less than that in the control group, and the difference was statistically significant ( P<0.05) . The methylation level of mitochondrial MT-COI site 2 (2.31±0.96%) in the case group was less than that in the control group, and the difference was statistically significant ( P<0.05) . The methylation average level of mitochondrial MT-COI (2.26±0.75) % in the case group was less than that in the control group, and the difference was statistically significant ( P<0.05) . Analysis of the average level of methylation found that the methylation level of mitochondrial MT-COI was correlated with WBC ( P<0.05) . Analysis of the average level of methylation found that the methylation level of mitochondrial MT-COI was correlated with platelets ( r=0.254、0.280, P<0.05) . Conclusion:The level of mitochondrial MT-COI gene methylation in patients with occupational chronic benzene poisoning may be related to the sensitivity to benzene exposure. Mitochondrial MT-COI gene methylation may serve as a potential predictive biomarker for benzene poisoning.

OBJECTIVETo investigate the cytochrome P450 2E1 (CYP2E1) RsaI/PstI and DraI polymorphisms in workers exposed to benzene.

METHODSA cross-sectional survey was carried out. A total of 71 workers exposed to benzene were included in observation group and the same number of people without occupational benzene exposure were included in control group. Blood samples from the two groups were collected and genotyping for CYP2E1 RsaI/PstI and DraI were conducted using the polymerase chain reaction-restriction fragment length polymorphism.

RESULTSThere were no significant differences in CYP2E1 DraI genotype and allele distributions between the observation group and the control group (χ² = 2.374, P > 0.05; χ² = 2.113, P > 0.05). Significant differences in CYP2E1 RsaI/PstI genotype and allele distributions between the two groups were observed (χ² = 9.129, P < 0.01; χ² = 6.028, P < 0.05).

CONCLUSIONMutations at CYP2E1 RsaI/PstI can enhance the expression of CYP2E1 and this suggests individuals with the mutated gene have increased susceptibility to chronic benzene poisoning.

Alleles ; Benzene ; poisoning ; Cross-Sectional Studies ; Cytochrome P-450 CYP2E1 ; genetics ; metabolism ; Genetic Predisposition to Disease ; Genotype ; Humans ; Poisoning ; genetics ; Polymerase Chain Reaction ; Polymorphism, Genetic ; genetics ; Polymorphism, Restriction Fragment Length

OBJECTIVETo investigate the cytotoxicity of indium chloride (InCl₃) and its effects on micro-nucleus formation in primary human lymphocytes cultured in vitro.

METHODSThe CCK-8 assay was used to evaluate the cytotoxicity of 24 h exposure to different concentrations of InCl₃(4, 40, 80, 200, 500, and 1 000 µmol/L) in lymphocytes cultured in vitro. The cytokinesis-block method was used to determine the micronucleus level in lymphocytes exposed to different concentrations of InCl₃and the effects of anti-oxidant vitamin C on micronucleus frequency.

RESULTSLymphocytes exposed to InCl₃of no less than 500 µmol/L had significantly lower survival rates than those in the control group (P < 0.05). Lymphocytes exposed to 80 µmol/L InCl₃had a significantly higher micronucleus frequency than those in the control group (P < 0.05). However, there was no further increase in micronucleus frequency of lymphocytes exposed to 200 µmol/L InCl₃. Lymphocytes cultured in whole blood and exposed to 500 or 1000 µmol/L InCl₃had a significantly increased micronucleus frequency than those in the control group (P < 0.001). The increase in micronucleus frequency of lymphocytes induced by indium could be partially antagonized by 20 or 100 µmol/L vitamin C.

CONCLUSIONInCl₃can induce an increase in micronucleus frequency of primary human lymphocytes cultured in vitro, which might be associated with DNA damage induced by oxidative stress.

Cell Nucleus ; metabolism ; Cytokinesis ; DNA Damage ; Humans ; In Vitro Techniques ; Indium ; toxicity ; Lymphocytes ; drug effects ; Oxidative Stress

Objective:To investigate the changes in liver function and peripheral regulatory lymphocytes before and after treatment in patients with occupational medicamentosa-like dermatitis due to trichloroethylene (OMDT) .Methods:In December 2019, 16 patients with OMDT (8 patients with erythema multiforme and 8 with erythema multiforme major) who were admitted from February 2017 to February 2019 were enrolled as subjects. Liver function parameters and percentages of peripheral regulatory lymphocytes were measured before and after treatment, and the changes in liver function and peripheral regulatory T and B lymphocytes and their correlation were analyzed.Results:Before treatment, compared with the healthy control group, the experimental group had significantly higher levels of alanine aminotransferase (ALT) , aspartate aminotransferase (AST) , total bilirubin (TBIL) , direct bilirubin (DBIL) and gamma-glutamyl transpeptidase (GGT) and significantly lower levels of total protein (TP) , albumin (ALB) and cholinesterase (CHE) ( P<0.05) . Compared with the healthy control group, the experimental group had significantly lower percentages of lymphocytes, CD4 + T cells, CD4 +CD25 + Tregs, CD19 +CD24 +CD27 + Bregs and CD4 +/CD8 + ratio, as well as a significantly higher percentage of CD8 + T cells ( P<0.05) . Before treatment, the levels of ALT, AST, GGT and DBIL were negatively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 + Bregs, CD4 + T cells and CD4 +/CD8 + ratio ( r=-0.386 to -0.809, P<0.05) and was positively correlated with the percentage of CD8 + T cells (except DBIL) ( r=0.503-0.568, P<0.05) . The levels of TP and ALB were positively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 + T cells ( r= 0.351-0.784, P<0.05) , ALB was negatively correlated with the percentage of CD8 + T cells ( r=-0.315, P<0.05) . CHE was positively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 +/CD8 + ratio ( r=0.390-0.527, P<0.05) . Conclusion:Immune dysfunction is observed in patients with OMDT, which may be caused by the imbalance of regulatory lymphocytes. And liver injury may be associated with the increase of CD8 + T cells and the reductions of percentages of CD4 + T cells, CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 +/CD8 + ratio.

Objective:To investigate the changes in liver function and peripheral regulatory lymphocytes before and after treatment in patients with occupational medicamentosa-like dermatitis due to trichloroethylene (OMDT) .Methods:In December 2019, 16 patients with OMDT (8 patients with erythema multiforme and 8 with erythema multiforme major) who were admitted from February 2017 to February 2019 were enrolled as subjects. Liver function parameters and percentages of peripheral regulatory lymphocytes were measured before and after treatment, and the changes in liver function and peripheral regulatory T and B lymphocytes and their correlation were analyzed.Results:Before treatment, compared with the healthy control group, the experimental group had significantly higher levels of alanine aminotransferase (ALT) , aspartate aminotransferase (AST) , total bilirubin (TBIL) , direct bilirubin (DBIL) and gamma-glutamyl transpeptidase (GGT) and significantly lower levels of total protein (TP) , albumin (ALB) and cholinesterase (CHE) ( P<0.05) . Compared with the healthy control group, the experimental group had significantly lower percentages of lymphocytes, CD4 + T cells, CD4 +CD25 + Tregs, CD19 +CD24 +CD27 + Bregs and CD4 +/CD8 + ratio, as well as a significantly higher percentage of CD8 + T cells ( P<0.05) . Before treatment, the levels of ALT, AST, GGT and DBIL were negatively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 + Bregs, CD4 + T cells and CD4 +/CD8 + ratio ( r=-0.386 to -0.809, P<0.05) and was positively correlated with the percentage of CD8 + T cells (except DBIL) ( r=0.503-0.568, P<0.05) . The levels of TP and ALB were positively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 + T cells ( r= 0.351-0.784, P<0.05) , ALB was negatively correlated with the percentage of CD8 + T cells ( r=-0.315, P<0.05) . CHE was positively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 +/CD8 + ratio ( r=0.390-0.527, P<0.05) . Conclusion:Immune dysfunction is observed in patients with OMDT, which may be caused by the imbalance of regulatory lymphocytes. And liver injury may be associated with the increase of CD8 + T cells and the reductions of percentages of CD4 + T cells, CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 +/CD8 + ratio.