[Effect of occupational stress on depression in gas field workers].

Objective: To explore the occurrence level of depressive symptoms and it's influencing factors among gas field workers. Methods: In October 2018, a cross-sectional study was conducted in 1726 gas field workers from a gas field by using cluster sampling method. Questionaire was used to evaluate the individual factors, depressive symptoms, occupational stress factors and stress regulatory factors. The correlation between depressive symptoms and occupational stress was analyzed. Multivariate logistic regression was used to analyze the influencing factors of depressive symptoms. Results: The depressive symptoms score of gas field workers was 12.00 (7.00, 19.00) point. Correlation analysis revealed that depressive symptoms score was positively related to sleep disorders (r=0.598) , effort (r=0.186) , daily tension (r=0.478) , negative affectivity (r=0.565) , social support (r=0.446) and monotony of work (r=0.484) (P<0.01) . And it was negatively related to reward (r=-0.386) , work stability (r=-0.294) , promotion opportunities (r=-0.258) , positive affectivity (r= -0.310) , self-efficacy (r=-0.312) , contral strategy (r=-0.268) , support strategy (r=-0.209) and job satisfaction (r=-0.398) (P<0.01) . Multivariate logistic regression analysis revealed that sleep disorder, high negative affectivity, low support from colleagues, low support from family, high monotony of work and high daily tension were the risk factors for depressive symptoms of gas field worker (OR=3.423, 95%CI: 2.644-4.397; OR=2.847, 95%CI: 2.200-3.683; OR=1.646, 95%CI: 1.215-2.116; OR=1.496, 95%CI: 1.164-1.923; OR=1.578, 95%CI: 1.227-2.303; OR=1.903, 95%CI: 1.480-2.440; P<0.01) . High work stability, high self-efficacy and high job satisfaction were protective factors for depressive symptoms of gas field workers (OR=0.752, 95%CI: 0.591-0.958; OR=0.590, 95%CI: 0.465-0.749; OR=0.718, 95%CI: 0.516-0.999; P<0.05) . Conclusion: Occupational stress factors have a great influence on the depressive symptoms of gas field workers. Increased work stability, self-efficacy and job satisfaction could reduce the risk of depressive symptoms.

[Correlation between social support and occupational stress among gas production workers in the field].

Objective: To investigate the level of social support and its correlation with occupational stress among gas production workers in the field. Methods: In October 2018, the cluster sampling method was used to perform a cross-sectional survey for 1726 gas production workers in the field, and related data of these workers were collected, including age, education level, marital status, level of social support, and related factors for occupational stress. A Spearman's rank correlation analysis was used to investigate the correlation between social support and occupational stress, and the levels of occupational stress-related factors were compared between the groups with different social support scores. Results: The gas production workers in the field had a median (25th percentile, 75th percentile) social support score of 24.00 (19.00, 28.00) , and there was a significant difference in social support score between the workers with different posts or work shifts (P<0.01) . Social support score was positively correlated with effort, daily stress, negative emotion, and job routinization (P<0.05) and was negatively correlated with job satisfaction, reward, working stability, and promotion opportunity (P<0.05) . The group with a high social support score had significantly higher scores of effort, job routinization, sleep disorders, and daily stress than the other two groups (P<0.01) , and the group with a low social support score had significantly higher scores of reward, self-efficacy, positive affection, and job satisfaction than the other two groups (P<0.01) . Conclusion: High-level social support plays an important role in alleviating occupational stress and protecting mental health among gas production workers in the field.

[Interaction of shift work and psychological capital on abnormal glucose and lipid metabolism among natural gas field workers].

Objective: To explore the interaction between shift work and psychological capital on abnormal glucose and lipid metabolism. Methods: A convenient sampling survey of demographics characteristics, shift work and psychological capital was conducted on 1 415 natural gas field workers by questionnaire in October 2018,and their physiological and biochemical indexes were measured according to standard norms. Multivariate logistic regression model was used to analyze the interaction between shift work and psychological capital on abnormal glucose and lipid metabolism. Results: For 1 415 subjectsthe prevalence of abnormal blood glucose was 21.2%, the prevalence of diabetes was 8.3%.The prevalence of abnormal total cholesterol was 40.4%, the prevalence of hypercholesterolemia was 11.3%.The prevalence of abnormal triglyceride was 41.6%, the prevalence of hypertriglyceridemia was 24.7%.The detection rate of Low-density Lipoprotein was 17.3%, the detection rate of Low-density Lipoprotein was 4.0%, and the detection rate of high-density Lipoprotein was 1.3%. Multiple logistic regression model analysis showed that shift work, the low level of self-efficacy and the low level of optimism was positively associated with abnormal blood glucose, respectively (P<0.05). Shift work was positively associated with abnormal triglyceride (P<0.05). However, there was no interaction between shift work, low self-efficacy, low hope, low resilience, and low optimism on abnormal glucose and lipid metabolism. Conclusion: Shift work was a risk factor of abnormal blood glucose and triglyceride, self-efficacy and optimism were protective factors of abnormal blood glucose. There was no multiplicative interaction between shift work and psychological capital on abnormal glucose and lipid metabolism in the study population.

[Sleep quality and occupational stress relationship analysis of field gas recovery workers].

Objective: To explore the relationship between sleep quality and occupational stress in field gas recovery workers. Methods: In October 2018, cluster sampling method was adopted to conduct cross-sectional survey on 1726 field workers in a gas production oilfield. The individual characteristics, occupational stress factors, stress regulation factors, stress response and sleep quality, social support and coping strategies were evaluated by occupational stress measurement tools and job content questionnaire. Mann Whitney U test and Kruskal Wallis H test were used to compare sleep quality scores between the groups. Spearman rank correlation analysis was used to analyze the correlation between sleep quality and occupational stress, and logistic regression analysis was used to analyze multiple factors. Results: There were significant differences in sleep quality scores among different positions, gender, marital status, age, length of service, smoking and drinking (P<0.05) . There were no significant differences in sleep quality scores between different education levels and work shift groups (P>0.05) . Spearman rank correlation analysis showed that sleep quality score was negatively correlated with job satisfaction, reward, job stability, promotion opportunity, positive emotion, respect, self-esteem, control strategy, support strategy and self-efficacy score (r(s)=-0.361, -0.311, -0.238, -0.261, -0.248, -0.212, -0.139, -0.188, -0.152, -0.226, P<0.01) , and was positively correlated with social support, giving, daily tension, negative emotion, work monotony and depression symptom (r(s)=0.312, 0.279, 0.547, 0.493, 0.429, 0.599, P<0.01) . Compared with the high sleep quality score group, the middle and low sleep quality score groups had lower giving, work monotony, daily tension, depressive symptoms, negative emotions and social support (P<0.01) , while the scores of respect, reward, job satisfaction, positive emotion, self-efficacy, job stability, promotion opportunity, control strategy and support strategy were higher (P<0.01) . Multiple depressive symptoms, high daily tension, high negative emotion and high work monotony were the risk factors for sleep disorders (OR=3.417, 2.659, 2.913, 1.543) . Conclusion: Depressive symptoms, daily tension and negative emotion have great influence on sleep quality of field gas recovery workers.

[Influence of Toll-like receptor 7 on CD8(+) T lymphocytes in patients with breast cancer].

Objective: To investigate the effect of Toll-like receptor 7 (TLR7) in CD8(+) T cells activity from patients with breast cancer. Methods: Thirty-three patients with breast cancer, twenty-three patients with benign breast tumor, and twenty healthy individuals were collected from The First Affiliated Hospital of Xinxiang Medical University between December 2017 and March 2018. Peripheral blood mononuclear cells (PBMCs) were isolated, and CD8(+) T cells were purified. TLR7 protein and mRNA relative expression in CD8(+) T cells was measured using flow cytometry and real-time PCR, respectively. mRNA relative expressions corresponding to perforin, granzyme B, and FasL in CD8(+) T cells were measured in response to TLR7 agonist stimulation. Direct/indirect contact co-culture system of CD8(+) T cells and breast cancer cell line MCF-7 was also used to assess cytolytic and noncytolytic function in response to TLR7 agonist CL097 stimulation. Results: The mean fluorescence intensity corresponding to TLR7 protein in CD8(+) T cells from breast cancer patients was 124.0±15.32, which was significantly down-regulated in comparison with benign breast tumor patients (255.5±54.91) and healthy individuals (261.9±68.65) (P<0.000 1). TLR7 mRNA relative level was also remarkably reduced in CD8(+) T cells from breast cancer patients (1.97±1.18) in comparison with benign breast tumor patients (4.84±1.01) and healthy individuals (4.75±1.40) (P<0.000 1). TLR7 agonist CL097 stimulation notably increased mRNA relative levels of perforin and granzyme B mRNA in CD8(+) T cells (P<0.01), but not elevated FasL mRNA (P>0.05).Furthermore, TLR7 agonist CL097 stimulation enhanced the cytolytic and noncytolytic function of CD8(+) T cells to MCF-7 cells, which presented as the elevation of target cell death and increase of interferon-γ production in direct and indirect contact co-culture system. Conclusion: TLR7 agonist promoted CD8(+) T cells function from breast cancer patients.

Identification of the immunodominant regions of the Em18 antigen and improved serodiagnostic specificity for alveolar echinococcosis.

The aim of this work was to identify the immunodominant regions of the Em18 antigen to improve the specificity in diagnosis of alveolar echinococcosis (AE). Two recombinant antigens ReEm18-1 and ReEm18-2, which have the same sequence except that nine amino acid residues are absent in ReEm18-2, were tested by ELISA and Western Blot (WB) for their diagnostic efficiency. Serological evaluation of the two antigens demonstrated that the sensitivity of both antigens was 95.5% in ELISA and WB, and the specificity was 93.6% and 95.7% in ELISA, and 81.4% and 82.9% in WB, respectively. Five more expression clones (EmS1-EmS5), which contain different regions of the Em18 sequence, were constructed for defining the immunodominant regions of the antigen. Fourteen monoclonal antibodies (mAbs) against ReEm18-2 antigen and the sera from different groups of patients were used to identify the epitope regions of the five antigen fragments. Results showed that the epitopes recognized by the mAbs are located in the N-terminal third of the sequence, but the immunodominant area recognized by native serum antibodies may be located further downstream (C-terminal) in the sequence. The nonspecific cross-reactivity is due to epitopes present in the C-terminal third of the sequence. The antigen fragments that contain the first two-thirds of the sequence have the same sensitivity to AE sera as those of the ReEm18-1 and ReEm18-2 antigens, but removal of the C-terminal third of the sequence improved the specificity of the assay from 93.6% to 99.3% (ELISA) and 81.4% to 90.7% (WB). We conclude that the necessary part of the ReEm18 antigen sequence for AE diagnosis is the N-terminal half to two-thirds of the entire sequence.

[Application of dot immunogold filtration assay in antibody detection for cysticercosis].

OBJECTIVE: To detect serum antibody of cysticercosis by dot immunogold filtration assay for establishing a diagnostic kit for cysticercosis patients. METHODS: Cyst fluid of cysticercus of Taenia solium after dialysis was used as diagnostic antigen in dot immunogold filtration assay and enzyme-linked immunosorbent assay to detect the serum antibody in patients with cysticercosis. Samples to be detected included 71 sera from patients with cysticercosis, 90 sera from healthy people, 20 sera from patients with other parasitic infections or brain tumor. RESULTS: The sensitivity and specificity of dot immunogold filtration assay were 90.1%(64/71) and 95.6%(86/90), respectively. No positive reaction was recorded in cases with other diseases except one serum from a patient with brain tumor. The coincidence rate between dot immunogold filtration assay and enzyme-linked immunosorbent assay was 94.4% (152/161). CONCLUSION: Dot immunogold filtration assay showed promising result for the diagnosis of cysticercosis.

[Comparison of circulating antigen detection in schistosomiasis japonica patients using two methods of ELISA].

OBJECTIVE: To compare 2 kinds of ELISA methods for detecting circulating antigen in schistosomiasis patients. METHODS: Monoclonal antibody-based dot-ELISA and sandwich ELISA. RESULTS AND CONCLUSION: The positive rates of dot-ELISA were higher than or similar to those of sandwich ELISA, the former being 48.0%-98.8% and the latter being 12.0%-93.8%. The specificities were 95.4%-100% and 90.0%, respectively.

Strain complex of Schistosoma japonicum in the mainland of China.

The present paper deals with studies on the characteristics of Schistosoma japonicum isolated from five localities in the mainland of China. The following items were observed and compared including morphometric data, susceptibility of six mammalian hosts, prepatent period, compatibility between larvae and snail hosts, size of hepatic granuloma produced by eggs, immunoreactions in experimental animals, sensitivity to praziquantel, SDS-PAGE protein pattern and its antigenicity analysis, DNA hybridization and genetic variation and differentiation by analysis with multilocus enzyme electrophoresis. By means of these multidisciplinary methods, from morphological to molecular level, the following conclusions may be drawn from our results. The evidence indicates firstly that S. japonicum in the mainland of China comprises a strain complex with several components of geographically distributed strains. At least four distinct strains exist, ie Yunnan, Guangxi, Sichuan and Anhui-Hubei. Characteristics of each strain are distinct and the results of these studies lead to discussion on the problem of the intraspecific and interstrain differentiation of S. japonicum in the mainland of China.

SDS-PAGE protein pattern and its antigenicity analysis of different isolates of Schistosoma japonicum in China.

Homogenates prepared from S. japonicum adult worms of different isolates from Anhui, Hubei, Guangxi, Yunnan and Sichuan Provinces were analyzed by SDS-PAGE and enzyme linked immunoelectrotransfer blot (EITB) tested with rabbit anti-snails antibody. The results of SDS-PAGE indicated that with silver staining both male and female worms of Guangxi isolate showed some definite differences in their protein profile, namely, absence of one band between 50-75 kDa in male worms and marked reduction in quantity of > 110 and 30 kDa bands in female worms. There was no obvious difference among other isolates both in male and female worms. The EITB patterns were similar in S. japonicum of Anhui and Hubei, and it was also the case with isolates from Yunnan and Sichuan, except that Yunnan female worms had a distinct band at 84 kDa which could hardly be seen in EITB pattern of Sichuan female worms; female worms of Guangxi isolates also showed a distinct 84 kDa band. The EITB pattern of male worms from Guangxi isolates showed 2 main bands of MW > 130 kDa against anti-Anhui snail antiserum which corresponded with the result of male worms of Anhui isolates. But these bands could not be seen with male worms from isolates of Yunnan and Sichuan.

[Characterization of Echinococcus granulosus and Echinococcus multilocularis by DNA probe].

Cloned DNA fragments pHD5, pSM889 and pEG18 have been used as DNA probes in the restriction endonuclease analysis and southern blot hybridization to characterize E. granulosus and E. multilocularis protoscolices from China. Southern blot hybridization method is sensitive, specific and has the advantage in identification over microscopic examination. The authors deem that it can be used in the base-line epidemiological survey and surveillance of hydatid disease to provide data for hydatid disease control.

[RFLP analysis of DNA from Echinococcus granulosus collected from four provinces/autonomous region in China].

A fragment of the ribosomal RNA gene of Schistosoma mansoni pSM889 and two DNA fragments specific to Echinococcus granulosus pHD5 and pEG18 have been used as DNA probes to assess the extent of genetic variability within E. granulosus. The DNA analysis, including restriction endonuclease digestion and Southern blot hybridization with the probes, did not demonstrate any genetic variation among E. granulosus collected from sheep in Xinjiang, Qinghai, Gansu and Ninxia. Similarly, there was no genetic variation among E. granulosus isolates collected from yak in Qinghai and Gansu provinces. The authors deemed that the yak isolates and the sheep isolates of E. granulosus appear to belong to a same strain.

[Studies on the strain differences of Schistosoma japonicum in the mainland of China. XI. Enzyme linked immunoelectrotransfer blot analysis].

Antigens prepared from S. japonicum adult worms of different isolates i. e. Anhui, Hubei, Guangxi, Yunnan and Sichuan by origin were analyzed by enzyme linked immunoelectrotransfer blot (EITB) probed with rabbit anti-snail antibody (Figs 1,2). Anti-sera against Oncomelania h. hupensis from Anhui, Hubei, Yunnan and Sichuan localities were prepared separately and used in the tests. The EITB patterns were similar in S. j. isolates of Anhui and Hubei, and it was also the case among S. j. isolates of Yunnan and Sichuan except Yunnan female worms with a marked band of 84 kDa but it was almost invisible in EITB pattern of Sichuan female worms. Like Yunnan isolate, female worms of Guangxi isolate also showed marked 84 kDa bands. The EITB pattern of male worms from Guangxi isolate showed 2 main bands of mw > 130 kDa against anti-Anhui snail anti-serum, which corresponded with the male worms of Anhui isolate whereas the color of the bands was darker and denser in the former isolates, and these bands can not be seen in the male worms from isolates of Yunnan and Sichuan. Based on the above mentioned results in connection with the information about the susceptibility between different isolates of schistosomes and their snail hosts which we have reported before, some preliminary analysis and discussion were made.

[Studies on the strain differences of Schistosoma japonicum in the mainland of China. X. Comparison of SDS-page protein patterns].

The purpose of the present study was to investigate the SDS-PAGE separation of proteins of the 5 different isolates of Schistosoma japonicum from the mainland of China to determine their similarities and/or differences and to gain additional data which could give an added insight into the degree of relationship. Soluble proteins of freshly sonicated adult worm extract of the 5 different isolates (i.e., Anhui, Hubei, Guangxi, Sichuan and Yunnan) were compared by SDS-polyacrylamide gel electrophoresis. The results indicated that no marked difference could be observed among the isolates after gels were stained by Coomassie blue white both male and female worms of Guangxi isolate showed some definite differences in their protein profile, i.e., lack of 50-75 kDa band in male worms and a marked reduction in the quantity of > 110 and 30 kDa bands in female worms as shown by silver stain.

[Studies on the strain differences of Schistosoma japonicum in the mainland of China. VIII. Immunoreactions in experimental animals].

Observations on the immunoreactivities toward egg antigens of different experimental animals infected with Schistosoma japonicum were made, which included mouse, rat, hamster, rabbit and rhesus monkey. The cercariae applied for infection were shed by snails collected from 5 different isolates, i.e., Anhui, Hubei, Sichuan, Yunnan and Guangxi in the mainland of China. Sera from the same sort of animals were separately pooled according to the different sources of infection mentioned above. Antibody reactivities were evaluated by COPT, LAT and ELISA. In COPT each serum sample was tested with ova from homologous and heterologous isolates, whereas soluble egg antigen merely prepared from Anhui isolate was used in LAT and ELISA. The level of antibodies detected by homologous or heterologous worm isolate antigens was compared. The results suggested that the positive antibody detection rate might not be influenced by antigens prepared from S. japonicum eggs of different isolates in the mainland of China.

[Isolation of germinal cells from the secondary cysts of Echinococcus granulosus harbored in mice].

The secondary cyst tissues derived from mice infected with protoscoleces of Echinococcus granulosus for 8-10 months were digested with 0.25% trypsin at 37 degrees C for 30 min. The separation of different cells in the remaining suspension was achieved by discontinuous gradient centrifugation. The germinal cells were washed 3 times with ice-cold HBSS, and then cultivated in the medium of RPMI 1640 supplemented with 20% of calf serum. The cells were kept in an incubator at 37 degrees C in an atmosphere of 95% air-5% CO2. After incubation for 5-7 days, the germinal cells began to multiply accompanied by the enlargement of cells as compared with those before incubation. The surface of both isolated and/or cultured cells showed smooth appearance examined by scanning electron microscopy. Immunofluorescence assay and enzyme-linked immunosorbent assay had been used for examining the specific antigenicity of the cells. The results showed that antigen components of E. granulosus were detected either on cell surface or in soluble proteins of the cells. Furthermore, 120 NIH female mice were inoculated intraperitoneally with 1-5 x 10(7) cultured germinal cells and sacrificed 1-3 months after inoculation. Only 2 cystic materials had been detected in two mice. Of which, one located in the liver and the other in peritoneal cavity of the animals. Histological examination noted that the cystic materials consisted of germinal layer and cyst fluid, but no laminated layer was observed. The above mentioned evidence demonstrated that the cells isolated from the cysts of E. granulosus were germinal cells.(ABSTRACT TRUNCATED AT 250 WORDS)

[Detection of circulating membrane antigen of schistosome in schistosomiasis by dot-ELISA and idiotype/antiidiotype interaction inhibition test].

A monoclonal antibody (designated 8SE) against membrane antigen of adult Schistosoma japonicum labeled with HRP was used in dot-ELISA (direct method) to detect schistosomal circulating membrane antigen. Sera from 48 parasitologically confirmed schistosomiasis cases were tested, 39 (81.3%) were positive. No false positive reaction was found in sera from 24 healthy controls. No cross reaction was detected in sera from clonorchiasis or paragonimiasis in 18 cases each. This results suggest that circulating membrane antigen does exist in patients with schistosomiasis and it might be used as a complementary method for diagnosis of schistosomiasis. A preliminary result of idiotype/antiidiotype interaction inhibition reaction for detecting circulating membrane antigen was also presented.

[Construction of Echinococcus granulosus genomic library].

Using EMBL3 phage DNA as a vector, a perfect genomic library of Echinococcus granulosus from sheep from Xinjiang has been constructed, which contains 1.2 x 10(6) independent recombinants. The main procedure of construction comprised: 1. extraction of Echinococcus granulosus genomic DNA, 2. partial digestion of the extracted E. granulosus genomic DNA with restriction enzyme Sau3Al, 3. harvest of 15-23 kb DNA fragments by electric elution equipment, 4. preparation of EMBL3 phage vector DNA, 5. cleavage of EMBL3 vector DNA with two restriction enzymes Bam HI and Eco RI to remove the central fragment, 6. ligation of the harvested 15-23 kb E. granulosus genomic DNA and the cleavaged vector DNA with T4 DNA ligase, 7. the package reaction of ligated recombinant DNA in vitro with the package protein and with Q359 strain (Spi-) to screen recombinants, 8. identification of the genomic library, 9. hybridization in situ by pSM889 probe, obtaining 6 positive recombinant clones. It was estimated that the E. granulosus genome was about 1.5 x 10(8) bp. A perfect E.g. genomic library is expected to contain 4.6 x 10(4) independent recombinants at minimum. The constructed genomic library has enough independent recombinants (1.2 x 10(6)). This is the first time to establish an E. granulosus genomic library in China. Previous work showed that there existed differences in many aspects, including pathogenicity, among various isolates of E. granulosus from different hosts and areas. We plan to employ this library to screen the E. granulosus intraspecies DNA probe by hybridization in situ. This kind of probe is envisaged to be of advantage for epidemiological investigation of the hydatid disease in China. It also provides a base for researching E. granulosus at the molecular level.

[Detection of circulating antigen and/or antigen-antibody complex by using McAb against surface membrane antigen of adult Schistosoma japonicum].

In the present paper, the results of detecting circulating antigen and/or antigen-antibody complexes by McAb against surface membrane antigen of adult Schistosoma japonicum were reported. The McAb, coded as 8SE4, was prepared by fusion of SP2/0 myeloma cells with spleen cells of the BALB/c mice immunized with the saline extract of adult S. japonicum. The 8SE4- directed antigen was proved to be located on the surface of the adult worm. After being purified by a DE52 column, 8SE4 was labelled with HRP and the conjugate (HRP-8SE4) was used in the test. For testing, the serum sample was first incubated with HRP-8SE4, then PEG (mw. 6,000) was added to precipitate the antigen-antibody complex. Upon centrifugation, OPD was added to the precipitate. Results were read by ELISA reader at 492nm. The OD value was found to be proportional to the amount of circulating antigen and/or antigen-antibody complexes. Results from 5 heavily infected (1,500-2,000 cercariae) rabbits showed that the OD values were raised significantly at the 6th week post infection, being 1.9-4.5 times higher than those before infection. The OD values of the 5 rabbits each lightly infected with 10-500 cercariae were also markedly raised 6 weeks post infection and reached the peak at the 8th week, then maintained in high levels until 11th week post infection. The worm burden of the 5 lightly infected rabbits were 4-326. No obvious correlations between OD values and worm loads were observed. The results suggested the existence of surface membrane-related antigen and/or antigen-antibody complexes in the circulation of infected rabbits.