Work-Related Stress and Occurrence of Cardiovascular Disease: A 13-Year Prospective Study.

OBJECTIVE: The aim of the study is to investigate the influence of work-related psychological and physical stresses on risk of cardiovascular disease (CVD). METHODS: A total of 5651 CVD-free participants older than 50 years from the Survey of Health, Ageing and Retirement in Europe were followed up for 13 years to detect incident CVD. Work-related stress was assessed using job strain and job reward questionnaire. Cox regression model was used to estimate the association. RESULTS: High physical demands (hazard ratio [HR], 1.30) and low reward (HR, 1.19) compared with their counterparts, as well as active physical jobs (HR, 1.41) and high physical strain (HR, 1.45) in comparison with low physical strain were associated with higher risk of incident CVD after adjusting for confounders. However, combining physically stressful jobs with low reward did not further increase the CVD risk. CONCLUSIONS: Avoiding physically stressful jobs or providing appropriate reward may reduce the occurrence of CVD.

Working life job strain status and cognitive aging in Europe: A 12-year follow-up study.

BACKGROUND: To examine the association of job strain with cognitive ability and the influence of life-course job strain on later life cognitive decline. METHODS: Data were derived from six waves of the Survey of Health, Aging, and Retirement in Europe. The study sample consists of 13349 participants aged 50 to 98 years at wave 2 and has been followed up for 12-years. Job strain status across working life was assessed using a short demand-control job strain model containing two core dimensions: job demands and job control collected in wave 3. Cognitive abilities concerning episodic memory was assessed by immediate recall and delayed recall tests, executive function was evaluated by verbal fluency test collected in all waves (waves 2-7) except wave 3. Mixed-effects model was used to estimate working life job strain and its cumulative effect on cognitive decline. RESULTS: Both passive and high strain jobs were associated with lower levels of cognitive ability (episodic memory and verbal fluency) in comparison with active job. Long exposure to active- or low strain-job was associated with higher cognitive ability whereas long exposure to passive job or moderate duration of high strain job was associated with lower cognitive ability. The rate of memory decline was positively related to moderate duration of passive job and negatively related to long-term exposure to low strain job. LIMITATIONS: Information on working conditions was based on self-reported recollections. CONCLUSIONS: Working life variation in job strain status and their duration may explain individual differences in cognitive ability in later life.

Depressive symptoms and cognitive impairment: A 10-year follow-up study from the Survey of Health, Ageing and Retirement in Europe.

BACKGROUND: Depressive symptoms and cognitive impairment often coexisted in the elderly. This study investigates the effect of late-life depressive symptoms on risk of mild cognitive impairment (MCI). METHODS: A total of 14,231 dementia- and MCI free participants aged 60+ from the Survey of Health, Ageing, and Retirement in Europe were followed-up for 10 years to detect incident MCI. MCI was defined as 1.5 standard deviation (SD) below the mean of the standardized global cognition score. Depressive symptoms were assessed by a 12-item Europe-depression scale (EURO-D). Severity of depressive symptoms was grouped as: no/minimal (score 0-3), moderate (score 4-5), and severe (score 6-12). Significant depressive symptoms (SDSs) were defined as EURO-D score ≥ 4. RESULTS: During an average of 8.2 (SD = 2.4)-year follow-up, 1,352 (9.50%) incident MCI cases were identified. SDSs were related to higher MCI risk (hazard ratio [HR] = 1.26, 95% confidence intervals [CI]: 1.10-1.44) in total population, individuals aged 70+ (HR = 1.35, 95% CI: 1.14-1.61) and women (HR = 1.28, 95% CI: 1.08-1.51) in Cox proportional hazard model adjusting for confounders. In addition, there was a dose-response association between the severity of depressive symptoms and MCI incidence in total population, people aged ≥70 years and women (p-trend <0.001). CONCLUSIONS: Significant depressive symptoms were associated with higher incidence of MCI in a dose-response fashion, especially among people aged 70+ years and women. Treating depressive symptoms targeting older population and women may be effective in preventing MCI.

The Role of Fibrocyte in the Pathogenesis of Silicosis.

Exposure to free silica induces silicosis and myofibroblasts are regarded as primary effector cells. Fibrocytes can differentiate into myofibroblast. Therefore, the present study was designed to investigate whether fibrocytes participate in silicosis. The rat model of silicosis was established. Hematoxylin-eosin stainings and Masson stainings were used to evaluate the histopathology and collagen deposition. Flow cytometry and immunofluorescence were performed to detect the number of fibrocytes and their contribution to myofibroblasts. Results showed that fibrocytes participate in silicosis. Trend analysis of different sources of myofibroblasts during silicosis indicated that fibrocytes and lung type II epithelial cell-derived myofibroblasts play an important role in the early stage of silicosis, while resident lung fibroblast-derived myofibroblasts play a predominant role during the fibrosis formative period.

Crystalline Silica Promotes Rat Fibrocyte Differentiation in Vitro, and Fibrocytes Participate in Silicosis in Vivo.

OBJECTIVE: The aim of this study was to investigate the effects of SiO2 on fibrocytes and whether fibrocytes participate in silicosis in vivo. METHODS: A macrophagocyte (AM)/fibrocyte coculture system was established, and AMs were treated with 100 µg/mL SiO2. Flow cytometry was used to detect the number of fibrocytes. Real-time PCR was performed to measure the expression of collagen I, collagen III, and α-SMA mRNA. The levels of collagen I, collagen III, and TGF-ß1 protein were determined by ELISA. Immunohistochemical staining was performed to measure α-SMA protein expression. A rat silicosis model was induced by intratracheal instillation of SiO2. Lung histopathological evaluation was conducted using HE and Masson's trichrome staining after 1 and 9 weeks. The number of fibrocytes in peripheral blood or lung tissue of rat was detected by flow cytometry. Double-color immunofluorescence was applied to identify fibrocytes in the lung tissue. RESULTS: Peripheral blood monocytes were found to differentiate into fibrocytes in vitro in a time-dependent manner, and exposure to crystalline silica might potentiate fibrocyte differentiation. In addition, fibrocytes were able to migrate from peripheral blood to the lung tissue, and the number of fibrocytes was increased after SiO2 exposure. CONCLUSION: Silica exposure potentiates fibrocyte differentiation, and fibrocytes may participate in silicosis in vivo.

Percutaneous transhepatic cholangiography and intraductal radiofrequency ablation combined with biliary stent placement for malignant biliary obstruction.

PURPOSE: To determine the safety and feasibility of percutaneous transhepatic cholangiography (PTC) and intraductal radiofrequency (RF) ablation combined with biliary stent placement for malignant biliary obstruction. MATERIALS AND METHODS: Data from patients with unresectable malignant biliary obstruction who underwent PTC, intraductal RF ablation, and biliary stent placement (n = 12) or PTC and biliary stent placement only (control group; n = 14) were reviewed. Postoperative complications, jaundice remission, and stent patency were assessed. RESULTS: All procedures were successful. No severe complications (eg, biliary bleeding, perforation) occurred. Two experimental group patients developed cholangitis, which resolved with conservative treatment. The 1-week jaundice remission and 3-month stent patency rates were similar in both groups, but the 6-month stent patency rate was higher in the experimental group (P < .05). In the experimental group, one death occurred as a result of gastrointestinal hemorrhage (unrelated to stent placement) by 3 months, and there were two cases of recurrent jaundice by 6 months. The latter two patients underwent repeat PTC, ablation, and stent placement. In the control group, one death occurred as a result of hepatic failure caused by progressive jaundice at 3 months, and another death resulted from disseminated intravascular coagulation caused by jaundice recurrence at 138 days after stent placement. In addition, seven patients developed jaundice recurrence (50-151 d after stent placement). PTC and repeat stent placement were performed in these patients. CONCLUSIONS: Percutaneous transhepatic cholangiography and intraductal RF ablation combined with biliary stent placement for malignant biliary obstruction is safe and feasible and effectively prolongs stent patency time.

[The expression of vascular endothelial growth factor antibody in serum of coal workers with pneumoconiosis].

OBJECTIVE: To determine the role of serum VEGF-Ab in pneumoconiosis of coal workers. METHODS: Four groups of participants were recruited for this study, including 230 with early stage (less serious than stage one) changes in relation to pneumoconiosis, 328 with confirmed coal worker pneumoconiosis, 309 workers exposed to coal dust, and 393 healthy people. All participants completed a questionnaire, and have their peripheral venous blood sample taken. Serum VEGF-Ab was detected by ELISA. RESULTS: Compared with healthy controls and those with early stage changes, the participants with pneumoconiosis and those exposed to coal dust had higher levels of serum VEGF-Ab (P < 0.05). The level of serum VEGF-Ab increased with the progression of stages of pneumoconiosis but without statistical significance (P > 0.05). In those with early stage pneumoconiosis, higher levels of serum VEGF-Ab were found in their 20 yr. - and 40 yr. - compared with those in their 60 yr. - (P < 0.05). By contrast, in those with confirmed pneumoconiosis and the healthy controls, lower levels of serum VEGF-Ab were found in their 20 yr. - and 40 yr. - compared with those in their 60 yr. - (P < 0.05). In those with early stage or first-stage pneumoconiosis, longer than 25 years work experience was associated with higher levels of serum VEGF-Ahb (P < 0.05). In those with confirmed pneumoconiosis, coal mining workers had a higher level of serum VEGF-Ab than their colleagues involving in assistance tasks (P < 0.05). In those exposed to coal dust, tunnelling workers had a higher level of serum VEGF-Ab than their coal mining colleagues (P < 0.05). CONCLUSION: Serum VEGF-Ab is associated with the occurrence and development of coal worker pneumoconiosis. The level of serum VEGF-Ab increases with age and length of exposure to dust.

Protein expression in silica dust-induced transdifferentiated rats lung fibroblasts.

OBJECTIVE: To analyze the expression of different proteins in free silica-induced transdifferentiated rat lung fibroblasts. METHODS: Rat lung fibroblasts and alveolar macrophages were cultured. A transdifferentiation model of rat lung fibroblasts was established. Free silica was used as a stimulator for rat lung fibroblasts. Changes in α-SMA were detected by immunohistochemistry and Western blot, respectively. Protein of lung fibroblasts was extracted and analyzed by two-dimensional electrophoresis (2-DE). RESULTS: Six protein spots were identified by mass spectrometry, including glyceraldehyde 3-phosphate-dehydrogenase, peroxiredoxin 5, heterogeneous nuclear ribonucleoprotein A2, transgelin 2, keratin K6 and vimentin. CONCLUSION: Some proteins are changed in free silica-induced transdifferentiated rat lung fibroblasts.

Role of insulin-like growth factor II receptor in transdifferentiation of free silica-induced primary rat lung fibroblasts.

OBJECTIVE: To study the role of insulin-like growth factor II receptor in free silica-induced transdifferentiation of primary rat lung fibroblasts. METHODS: Rat lung fibroblasts and rat alveolar macrophages were cultured. A transdifferentiation model of primary rat lung fibroblasts was induced by free silica. Levels of α-SMA protein, IGF-IIR protein and mRNA were measured by immunocytochemistry, Western blot and RT-PCR, respectively. Lung fibroblasts were treated with Wortmannin. RESULTS: The expression levels of α-SMA and IGF-IIR increased with the increasing free silica concentration and decreased after Wortmannin was used. CONCLUSION: The IGF-IIR plays an important role in free silica-induced transdifferentiation of primary rat lung fibroblasts.

[DNA methylation levels of genome in cFb transdifferentiation induced by SiO2 in rats].

OBJECTIVE: To explore the DNA methylation levels of genome in cFb transdifferentiation induced by SiO2 in rats. METHODS: The primary macrophages and fibrocytes of SD rats were co-cultured directly and indirectly, which were exposed to SiO2 at the doses of 25, 50 and 100 g/ml. The transdifferentiation of cFb was identified with immunohistochemical assay. The genomic DNA methylation levels of cFb were detected with HPLC. RESULTS: Under the condition of indirect co-culture, as compared with control group, the genomic DNA methylation levels of cFb exposed to SiO2 at the doses of 25, 50 and 100 g/ml reduced by 19.9%, 26.9% and 30.3%, respectively (P < 0.05); as compared with cFb exposed to 100 g/ml SiO2, the genomic DNA methylation levels of cFb exposed to 5-aza-dC decreased by 22.0% (P < 0.05). Under the condition of ThinCert(TM) direct co-culture, as compared with control group, the genomic DNA methylation levels of cFb exposed to SiO2 at the doses of 25, 50 and 100 g/ml reduced by 22.2%, 30.2% and 36.7%, respectively (P < 0.05); as compared with cFb exposed to 100 g/ml SiO2, the genomic DNA methylation levels of cFb exposed to 5-aza-dC decreased by 20.6% (P < 0.05). CONCLUSION: Under the co-culture condition in vitro, SiO2 could reduce the genomic DNA methylation levels of cFb. The ThinCert(TM) direct co-culture can be used to study the silicosis fibrosis.

[A meta-analysis of susceptibility to pneumoconiosis and polymorphism of tumor necrosis factor-α 308 and 238 locus].

OBJECTIVE: To explore the relationship between the polymorphism of TNF-α gene 308, 238 locus and the susceptibility to pneumoconiosis. METHODS: Eighteen published case-control studies about TNF-α gene 308, 238 locus polymorphism and pneumoconiosis susceptibility were searched out from sino-foreign databases from January 1994 to December 2010. Meta-analysis was applied on the published research to calculate the pooled OR value (95%CI) and stratified analyze the types and species of pneumoconiosis. RESULTS: Eleven of the published research articles were selected into the analysis, including 10 research focusing on TNF-α gene 308 locus, with 1408 cases and 1639 controls in total. The meta-analysis showed that comparing with Gln/Gln carriers, Arg/Arg, Arg/Gln, Gln/Arg + Arg/Arg carriers were 1.89-fold (95%CI: 1.10 - 3.24), 1.53-fold (95%CI: 1.25 - 1.87), and 1.56-fold (95%CI: 1.28 - 1.90) more susceptible to pneumoconiosis, respectively. The stratified analysis showed that among coal workers, the TNF-α gene 308 locus Arg/Arg, Arg/Gln, Gln/Arg + Arg/Arg carriers were separately 2.29-fold (95%CI: 1.22 - 4.29), 1.56-fold (95%CI: 1.20 - 2.03), 1.64-fold (95%CI: 1.28 - 2.11) more susceptible to pneumoconiosis than Gln/Gln carriers; and among Asian people, the TNF-α gene 308 locus Gln/Arg, Gln/Arg + Arg/Arg carriers were separately 1.58-fold (95%CI: 1.28 - 1.95) and 1.57-fold (95%CI: 1.28 - 1.94) more susceptible to pneumoconiosis than the Gln/Gln carriers. Four case-control research focus on the study of TNF-α gene 238 locus, including 391 cases and 391 controls in total. The analysis showed that comparing with the non-carriers, TNF-α gene 238 locus Arg/Arg, Arg/Gln, Gln/Arg + Arg/Arg carriers were 6.03-fold (95%CI: 1.35 - 26.97), 1.87-fold (95%CI: 1.07 - 3.30) and 2.36-fold (95%CI: 1.37 - 4.07) more susceptible to pneumoconiosis. CONCLUSION: TNF-α gene 308, 238 locus Arg/Arg, Gln/Arg, Gln/Arg + Arg/Arg carriers are more susceptible to pneumoconiosis.

[The relationship between the concentration of TGF-beta1 in serum and its gene polymorphisms in CWP].

OBJECTIVE: To study the relationship between the concentration of TGF-beta1, in serum and its gene polymorphisms in CWP. METHODS: 101 cases of coal worker's pneumoconiosis (CWP)were selected. And the peripheral vein blood samples were collected from them. The concentration of TGF-beta1 of their serum were detected with the TGF-beta1 ELISA kit. And their TGF-beta1 gene -509 site polymorphisms were analyzed with the polymerse chain reaction-restriction fragment length polymorphisms (PCR-RFLP) techniques. RESULTS: The mean value of TGF-beta1, concentration in serum of T/T, C/T and C/C gene type group were 90 ml, 60 ml and 55.960 +/- 28.833 ng/ ml respectively. Significant differences were observed within the three groups (P<0.05). The differences of the mean value of TGF-beta1, concentration in serum in various work years groups, age groups and in the groups with different stage of pneumoconiosis were not significant (P > 0.05). CONCLUSION: The correlative relationship between the concentration of transforming growth factor I (TGF-beta1) in serum and its gene -509 site polymorphisms might be occurring.