Silicosis Research Articles

The discriminant analysis of the silicosis's induction on cytokines in phlegm and combined multi-markers

To investigate the changes of cytokines in induced sputum at different stages of silicosis patients. A total of 200 workers from one of the Shandong Province gold mine were chosen as object of observation. Among which 40 patients at silicosis stage I and 40 patients at silicosis stage II were divided into silicosis observed object group, silicosis stage I group, silicosis stage II group, and another 80 workers exposed to silica dust without suffering from silicotic Clinical symptoms, however, were chosen as group of dust exposed, and 40 logistical workers without being exposed and history of silicosis's illness were chosen as control group. And ask their basic information by questionnaire. Then, spray-inhalation the induced sputum and apply the ELISA to assess the level of tumor necrosis factor (TNF), interleukin (IL), macrophage inflammatory protein-1 (MIP-1α), monocyte chemotactic factor-1 (MCP-1), metalloproteinases (MMP), transforming growth factor-β (TGF-β), platelet derived growth factor (PDGF) in induced sputum from subjects. The level of TGF-β [(901.60 ± 30.09) ng/L] in the induced sputumof patients in silicosis stage I group is lower than that in the observed object group [(913.02 ± 20.51) ng/L], and the level of MMP-9 [(212.49 ± 5.97) ng/L], MCP-1 [(129.91 ± 4.30) ng/L] has various degrees of increase than that in control group, observed object group and dust exposed group. All the differences have statistical significances (P < 0.05). The level of TNF-α [(85.76 ± 3.78) ng/L] in the induced sputum of patients in silicosis stage I group reaches the maximum, there are significant differences comparing with that level in the silica dust exposure group and the control group, whose differences are statistically significant (P < 0.05). Compared with the control group, the level of MMP-2 (427.95 ± 23.64) in the induced sputum of patients in silicosis stage I group has increased, whose differences also have statically significant (P < 0.05). Compared with the control group, silica dust exposed group, the observation group of objects, the pneumosilicosis patients of IL-16 in induced sputum IL-16 (21.40 ± 9.24) decreased, the content of PDGF [(5.96 ± 0.51) ng/L], MMP-2 [(447.86 ± 27.10) ng/L], MMP-9 [(223.91 ± 12.28) ng/L], MCP-1 [(122.87 ± 6.08) ng/L] increased, the differences are statistically significant (P < 0.05). As silicosis biomarkers, TNF-alpha, TGF-beta, IL-16, PDGF, MMP-2, MMP-9 and MCP-1 have certain significance, further suggesting that early detection rate of patients with silicosis can be improved by employing the multiple indexes discriminate equation.

Analyses on the characteristics and the trends of pneumoconiosis notified between 2001 and 2012 in Hebei Province

To describe the incidence, development and death of pneumoconiosis reported in Hebei from 2001 to 2012 and investigate the epidemiological trends and characteristics of pneumoconiosis to provide basic data for formulating the guidelines and policies for control of pneumoconiosis. The Hebei database of new cases of pneumoconiosis reposed from 2001 to 2012 were subjected to systematic arrangement. Clean data and descriptive analysis using SPSS 17.0. The statistical indices included number of new and death pneumoconiosis cases in each year. From 2001 to 2012 a total of 4558 new cases of pneumoconiosis were reported. The situation was same to coal-workers' pneumoconiosis and silicosis. (2) The pneumoconiosis cases were distributed mainly in the city of Tang Shan, Cheng De, Zhang Jia Kou and Han Dan (88.24%). (3) Most cases were centerred in coal industry, metallurgical industry, nonferrous metals industry, architectural material industry and light industry. (4) The mean age of onset in new cases was shorted each year for silicosis, coal-workers' pneumoconiosis, potter pneumoconiosis and electric welder pneumoconiosis, especially for 2010 to 2012 (9 years). (5) The work types of these cases mainly included drilling (26.72%), mining as the main work (6.67%), hybrid coal mine work (6.95%), molding worker (5.24%) and berterring worker (4.82%). (6) The new cases of pneumoconiosis reposed from 2001 to 2012 were diagnosissed I (3415, 74.92%), II (782, 17.16%), III (361, 7.92%). (7) The death cases of pneumoconiosis reposed from 2001 to 2012 were 1182, most of them were distributed mainly in the city of Tang Shan, Cheng De, Zhang Jia Kou and Han Dan (88.24%). The incidence of pneumoconiosis is still high: the new cases of pneumoconiosis is still rising. The mean age of onset in new cases was shorted each year. The new cases of pneumoconiosis reposed from 2001 to 2012 were diagnosed II was above 25%. The prevention and control of pneumoconiosis should be enhanced in key industries and for people engaging in key regions, industries, types of work according to the epidemiological characteristics of pneumoconiosis. Most cases were centerred in coal-workers' pneumoconiosis and silicosis.

Observation of the inflammatory factors level and the correlation between induced sputum and whole lung lavage fluid for silicosis

To detect the inflammatory factors of induced sputum (IS) and whole lung lavage fluid in pneumonoconiosis patients and to explore the correlation between the inflammatory factors with pulmonary function. The records of 45 cases of pneumonoconiosis patients were observed. All patients underwent lung function examination, sputum induction and massive whole lung lavage (WLL) sequentially through advance. IS and whole lung lavage fluid were collected respectively. Inflammatory factors of the two specimens were detected by using enzyme linked immunosorbent assay. The correlation of inflammatory factors between the two specimens was analyzed. The relationship between the inflammatory factor and lung function index was observed. The statistical analysis is performed with SPSS 17.0 for Windows. P < 0.05 is considered to be statistically significant. Cytokines (MCP-1, TNF-α MIP-1α, NO(2)(-)/NO(3)(-) and IL-16) were significantly associated between IS and whole lung lavage fluid (P < 0.05), while TNF-α, MCP-1, NO(2)(-)/NO(3)(-) and IL-16 were no significantly associated with lung function index (P > 0.05). MIP-1α was significantly associated with FEV(1.0)/VCmax and MEF(25), respectively (P < 0.05). Inflammatory factors were significantly associated between IS and whole lung lavage fluid, which could indicate early lung injury in pneumonoconiosis patients.

Quality of life and influencing factors for patients with silicosis: an analysis of 220 cases

To investigate the quality of life and influencing factors for patients with silicosis and to provide a basis for treatment of silicosis. Two hundred and twenty stone workers with silicosis from June 1999 to June 2014 were enrolled into observation group, while healthy stone workers within the same period were used as controls. The quality of life was evaluated using the Chinese version of the World Health Organization Quality of Life Assessment (WHOQOL-100), and the influencing factors were determined using stepwise multivariate regression analysis. The scores for psychological function, physiological, independence, spiritual realm, the overall quality of life, and physical condition in the observation group were significantly lower than those in the control group (t = 7.1168, P < 0.05; t = 3.8165, P < 0.05; t = 5.9230, P < 0.05; t = 2.7764, P < 0.05; t = 3.0761, P < 0.05). The scores for 11 items including pain, discomfort, energy, fatigue, sleep, and rest in the observation group were significantly lower than those in the control group (P < 0.05). Negative emotions, silicosis stage, recreation, age, reliance on health care, pain, discomfort, and spiritual beliefs were all influencing factors for the quality of life, which resulted in 68.3% of variation in the quality of life. Besides clinical treatment, health and psychological education and recreation are important for patients with silicosis to improve their quality of life.

Serum levels of matrix metalloproteinase 9 and 19 in the patients with pneumoconiosis

To measure peripheral serum levels of matrix metalloproteinase 9 (MMP9) and matrix metalloproteinase 19 (MMP19) in patients with pneumoconiosis, and to investigate their feasibility as potential biomarkers for pneumoconiosis. Ninety-eight male patients with pneumoconiosis (49 patients in phase I, 36 patients in phase II, and 13 patients in phase III) were enrolled as subjects, which included 41 patients with silicosis and 57 patients with coal workers' pneumoconiosis. Ninety-eight healthy male physical examinees were used as controls. A fasting blood sample (3 ml) was collected from the peripheral venous blood of each patient or control, and the serum was separated from the blood sample. The expression levels of MMP9 and MMP19 in serum were measured by enzyme-linked immunosorbent assay. Serum levels of MMP9 and MMP19 in patients with silicosis or coal workers' pneumoconiosis were significantly lower than those in the control group (P < 0.05). Serum levels of MMP19 in patients with silicosis were significantly higher than those in patients with coal workers' pneumoconiosis (P < 0.05). Serum levels of MMP19 in patients exposed to dust for less than 7 years were significantly higher than those in patients exposed to dust for more than 20 years (P < 0.05). There were no significant differences in serum levels of MMP9 and MMP19 between patients with different levels of pulmonary function impairment (P > 0.05). Serum expression levels of MMP9 and MMP19 were positively correlated with each other in both patients with pneumoconiosis and those in the control group (P < 0.05). The serum expression level of MMP9 was negatively correlated with the stage of pneumoconiosis (P < 0.05). Serum MMP9 and MMP19 may be used as potential biomarkers for pneumoconiosis.

Study on tissue Doppler imaging in diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease

To investigate the value of tissue Doppler imaging (TDI) in the diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease. A total of 50 cases of silicosis complicated by chronic pulmonary heart disease in our hospital underwent conventional electrocardiography (ECG) and TDI. The detection rates for right ventricular hypertrophy by two methods were compared. Of 50 cases of silicosis complicated by chronic pulmonary heart disease, 19 were diagnosed with right ventricular hypertrophy by ECG, with a detection rate of 38.0%; 29 were diagnosed with right ventricular hypertrophy by TDI, with a detection rate off 58.0%. Statistical analysis suggested that TDI leads to a significantly higher detection rate for right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease (χ² = 4.006, P = 0.036). Both TDI and ECG can be used for detecting right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease, but the detection rate is higher when TDI is employed. In addition, ECG cannot directly reflect the increase in pulmonary artery pressure. Therefore, TDI is more suitable for the diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease and provides a strong diagnostic basis for the clinical treatment of silicosis complicated by pulmonary heart disease.

Nursing of treating silicosis with pneumothorax by in dwelling chest catheterization with needle

尘肺并发自发性气胸是其严重并发症之一.由于其肺组织变薄,弹性减弱,肺泡易破裂形成肺大泡造成矽肺并发气胸,使原有肺功能进一步下降,所以确诊后应立即排气减压,使肺尽快复张,改善心肺功能.我们自2008年6月以来对27例32侧矽肺并发气胸应用留置带针胸管进行胸腔闭式引流术,取得了满意的效果,并有如下护理体会。

Advances in research on the role of Gas 6/TAMin inflammation response and silicosis induced by silica dusts

矽尘(游离SiO2)是我国危害最严重的职业有害因素,长期接触直接导致我国发病最高的职业病-尘肺,因此,矽尘及其致病效应受到广泛重视.矽尘的致病机制一直未能阐明,其引起免疫炎性反应被认为是其致病的起始[1-3].生长停滞特异性基因产物6(growth arrest-specific gene 6,Gas 6)是维生素K依赖性蛋白家族成员,与抗凝蛋白S属同源蛋白.已有研究证明Gas 6参与细胞信号传导,调节细胞存活、增殖,特别是在免疫反应的起始阶段进行细胞黏附和识别,可能在肺部炎症反应,以及自身免疫性疾病、心血管疾病、肿瘤和糖尿病等疾病的发生发展中发挥重要作用[4-8].本文就Gas 6/TAM结构特点、参与炎症反应的机制和Gas 6在矽肺发病过程中的可能作用进行综述。

Comparative proteomic analysis on anti-fibrotic effect of N-acetyl-seryl-aspartyl-lysyl-proline in rats with silicosis

To perform a comparative proteomic analysis for identification of pulmonary proteins related to the progression of silicosis and anti-fibrotic effect of N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP). Bronchial instillation of SiO₂powder (for 4 or 8 weeks) was applied in rats to establish a silicosis model. Ac-SDKP treatment was performed before (prevention group) or after (treatment group) SiO₂instillation. The control group was treated by bronchial instillation of sodium chloride solution of the same volume as SiO₂powder for 4 or 8 weeks. Proteins in lung tissue were separated by two-dimensional gel electrophoresis and stained with colloidal Coomassie brilliant blue. The gel images were scanned with the Lab Scan III system and analyzed with Imagemaster 6.0. The protein spots with significant differences between two groups (i.e., P value was less than 0.05 in One-way ANOVA) and with a change in volume over 30% were defined as differential proteins. Comparison was performed between the silicosis group and control group after 4 or 8 weeks, between the Ac-SDKP treatment group and silicosis group after 8 weeks, and between the Ac-SDKP prevention group and silicosis group after 8 weeks. The differentially expressed proteins were subjected to in-gel digestion with trypsin and MALDI-TOF-MS and Mascot search engine analysis to identify these proteins. Thirty-three differential proteins were identified. In comparison with the control group (4 weeks), the silicosis group (4 weeks) had 17 up-regulated proteins and 11 down-regulated proteins. In comparison with the control group (8 weeks), the silicosis group (8 weeks) had 16 up-regulated proteins and 12 down-regulated proteins. In comparison with the silicosis group (8 weeks), the Ac-SDKP treatment group had 5 up-regulated proteins and 6 down-regulated proteins, and the Ac-SDKP prevention group had 8 up-regulated proteins and 10 down-regulated proteins. Critical regulatory proteins related to silicotic fibrosis and anti-silicotic effect of Ac-SDKP have been identified. These proteins may play an important role in proliferation, apoptosis, inflammation, epithelial-mesenchymal transition, and signal transduction in silicosis.

Relationship between genetic polymorphisms of matrix metalloproteinase-2 and -3 and susceptibility to silicosis

To investigate the relationship between the genetic polymorphisms of matrix metalloproteinase-2 (MMP-2) (-735) and matrix metalloproteinase-3 (MMP-3) (-1171) and the susceptibility to silicosis. A case-control study was conducted in 113 patients diagnosed with stage I silicosis (case group) and 115 dust-exposed workers without silicosis (control group); the two groups had the same sex, ethnic group, and type of dust and similar age and cumulative exposure time. Polymerase chain reaction-restriction fragment length polymorphism was used to determine the genotypes of MMP-2 (-735) and MMP-3 (-1171). No significant difference was observed in age, cumulative exposure time, or smoking rate between cases and controls (P > 0.05). The frequencies of genotypes C/C, C/T, and T/T at MMP-2 C-735T in the case group were 57.5% (65/113), 31.0% (35/113), and 11.5% (13/113), respectively, which were significantly different from those of the control group (69.6% (80/115), 26.9% (31/115), and 3.5% (4/115)), χ² = 6.542, P < 0.05). The frequencies of T allele in cases and controls were 27.0% and 17.0%, respectively, which were significantly different from each other χ² = 6.704, P < 0.05). Carriage of T allele at MMP-2 C-735T increased the risk of silicosis (OR = 1.811, 95% CI: 1.151-2.847). The frequencies of genotypes 6A/6A, 5A/6A, and 5A/5A at MMP-3 A-1171A were 67.2% (76/113), 24.8% (28/113), and 8.0% (9/113), respectively, in the case group, versus 59.1% (68/115), 37.4% (43/115), and 3.5% (4/115) in the control group (χ² = 5.519, P > 0.05). Genetic polymorphism at MMP-2 C-735T is significantly associated with the development of silicosis. Carriage of T allele increases the risk of silicosis among workers exposed to dust. No significant association was found between MMP-3 A-1171A polymorphism and silicosis in this study.

Prevalence of silicosis among Xiangyang-Chongqing Railway construction workers 40 years after dust exposure

To investigate the prevalence of silicosis among workers who had participated in tunnelling of the Xiangyang-Chongqing Railway construction project and had returned to their home town and lived free of dust exposure for 40 years, and to provide a scientific basis for government decision. A total of 3417 civilian workers who had participated in tunnelling of the Xiangyang-Chongqing railway construction project during 1968 to 1972 were subjected to high-kV chest X-ray for primary examination. The suspected cases of silicosis underwent examination in Chongqing Center for Disease Control and Prevention for a confirmed diagnosis. Among the 3661 workers who were to undergo physical examination as planned, 3417 (93.34%) actually participated in this examination. The detection rate of silicosis was 9.34% (319/3417), including 192 cases of stage I, 116 cases of stage II, and 11 cases of stage III. No significant difference was found in average exposure time between different stages (F = 1.873, P > 0.05). The detection rate of silicosis was the highest among pneumatic drill workers, followed by tunnelling workers, blasters, supporting workers, and persons doing casual work. Significant difference was found in detection rate between different types of workers (χ² = 112.79, P < 0.05). Four decades after dust exposure, the prevalence of silicosis among workers who participated in tunnelling of the Xiangyang-Chongqing Railway construction project remains serious. Routine examination for silicosis, as well as documentation of patients' health status and follow-up investigation, should be carried out in these workers.

Study on effect of cordyceps sinensis on early-stage silicotic pulmonary fibrosis in rabbits

To establish a rabbit model of silicotic pulmonary fibrosis and to investigate the effect of cordyceps sinensis in this model. Thirty healthy male white rabbits were randomly divided into control group, silicosis model group, and intervention group. The rabbits in silicosis model group and intervention group received endotracheal perfusion of silicon dioxide suspension (120 mg/kg), and the control group was treated with the same volume of saline. All the rabbits were sacrificed 30 days later. The lung coefficient was calculated by comparing the lung weight and body weight; the right lung tissue was stained with hematoxylin-eosin (HE). The content of hydroxyproline in lung tissue was measured by alkaline hydrolysis. The mRNA levels of transforming growth factor beta 1 (TGF-β₁) and mothers against decapentaplegic homolog 7 (Smad7) in rabbit lung sections were determined by real-time PCR. No abnormalities were observed by HE staining in the lung tissues of control group, while fibrosis and silicotic nodules were discovered in the silicosis model group and intervention group. The lung coefficient and the content of hydroxyproline in lung tissue were significantly higher in the silicosis model group than in the control group and intervention group (P < 0.05 or P < 0.01). Compared with the control group, the silicosis model group and intervention group had significantly increased TGF-β₁ mRNA levels but significantly reduced Smad7 mRNA levels (P < 0.02). Compared with the silicosis model group, the intervention group had a significantly reduced TGF-β₁ mRNA level but a significantly increased Smad7 mRNA level (P < 0.05). Cordyceps sinensis is able to reduce the expression of TGF-β₁ mRNA and increase the expression of Smad7 mRNA in lung tissues of rabbits with silicotic pulmonary fibrosis, and thus postpone the progression of fibrosis.

Anti-fibrotic role of AcSDKP through inhibition of P38MAPK pathway activity mediated transforming growth beta receptors in rat with silicosis

To investigate the distribution and expression of transforming growth factor beta (TGF-β) receptors I and II, p38 mitogen-activated protein kinase (p38 MAPK), and type I and type III collagen in the lungs of rats with silicosis and cultured pulmonary fibroblasts, and to investigate the relationship of the anti-fibrosis effect of N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) with its inhibition of TGF-β receptor-mediated p38 MAPK pathway activity. Rats were randomly divided into control group, silicosis model group, and AcSDKP treatment group (n = 10 for each group). For the model group and AcSDKP treatment group, rats were intratracheally instilled with silica to establish a silicosis model. Cultured pulmonary fibroblasts from neonatal rats were divided into control group, TGF-β1 stimulation group, TGF-β receptor inhibition group, p38 MAPK pathway inhibition group, and AcSDKP treatment group. The protein expression of TGF-β receptors I and II, p38 MAPK, and type I and type III collagen were determined by immunohistochemistry and Western blot. The mRNA expression of TGF-β receptors I and II were determined by real-time PCR. The distribution and nuclear translocation of phospho-p38 MAPK in cultured fibroblasts were determined by laser scanner confocal microscopy. In the AcSDKP treatment group, AcSDKP reduced the expression of TGF-β receptors I and II, phospho-p38 MAPK, and type I and type III collagen to 86.12%, 41.01%, 42.63%, 89.05%, and 52.71%, respectively, of those of the silicosis model group (P < 0.05). In cultured fibroblasts, AcSDKP reduced the mRNA expression of TGF-β receptors I and II to 42.26% and 54.33%, respectively, of those of the TGF-β1 stimulation group; the protein expression of TGF-β receptors I and II, phospho-p38 MAPK, and type 1 and type III collagen was reduced to 58.14%, 51.40%, 45.6%, 58.04%, and 44.74%, respectively, of those of the TGF-β1 stimulation group. The phospho-p38 MAPK translocation from plasma to the nucleus was also inhibited; the nucleus/plasma ratio of p38 MAPK and the protein expression of type I and type III collagen were reduced to 68.60%, 58.04%, and 44.74%, respectively, of those of the TGF-β stimulation group (P < 0.05). AcSDKP can inhibit the expression of collagen through inhibition of TGF-β receptor-mediated p38 MAPK pathway activity, and is thus able to exert anti-fibrosis effect in rats with silicosis.

Screening and identification of key signal transduction pathways in pulmonary silicotic fibrosis

To investigate the differential gene expression profile of the lung tissues in experimental silicosis rats and to screen for and identify the key signal transduction pathways in pulmonary silicotic fibrosis. A total of 80 rats were randomly divided into control group (n = 40) and silica-instilled group (n = 40). Each group was equally divided into five subgroups, and each subgroup was treated at 1, 7, 14, 21, or 28 d. Intratracheal instillation was used to give 1 ml of silica suspension (50 mg/ml) in the silica-instilled group and normal saline in the control group. Silicotic nodules and type I and III collagen were observed through hematoxylin and eosin staining and Sirius red staining, respectively. Differentially expressed genes in pulmonary silicotic fibrosis were selected by the rat whole-genome gene expression RatRef-12 BeadChip (Illumina, USA), and a fold change cutoff was applied. Quantitative real-time polymerase chain reaction (qRT-PCR) was also used to verify differentially expressed genes. Through bioinformatics databases such as Visualization and Integrated Discovery (DAVID) and Kyoto Encyclopedia of Genes and Genomes (KEGG), preliminary research was performed on the biological pathways of differential genes, key biological signal transduction pathways were identified, and key differentially expressed genes in each pathway at different time points were searched for. A total of 2694 genes were differentially expressed and changed dynamically. The KEGG pathway analysis showed that 141 signal transduction pathways were involved in the development and progression of pulmonary silicotic fibrosis, among which 48 pathways were more significant than others (P < 0.01), with the mitogen-activated protein kinase (MAPK) pathway exceptionally significant. The differentially expressed genes interleukin-1 receptor (IL-1R), tumor necrosis factor receptor (TNFR), and transforming growth factor beta (TGF-β) in the MAPK pathway were up-regulated at different time points after silica instillation. The results of real-time PCR showed that granulocyte-macrophage colony-stimulating factor (GM-CSF) was over-expressed at 4 time points and under-expressed at 1 time point compared with the control group. The MAPK signal transduction pathway plays a very important role in the development of pulmonary silicotic fibrosis. Both IL-1R and TNFR may play major roles during inflammation phase through the P38/Jun N-terminal kinase (JNK) pathway, and TGF-β may have important function through the extracellular-signal-regulated kinase (ERK) pathway in the formation of fibrosis.

The pathological observation of lung's draining lymph node on 12 autopsy with coal workers

To investigate the pathological characteristics of draining pulmonary lymph nodes in coal workers' pneumoconiosis (CWP) and study their significance for the early diagnosis of CWP. The autopsy materials of 12 coal workers were subjected to HE staining and observed under a light microscope, and a retrospective analysis was performed considering the occupational history. The age range of 12 cases was 46∼71 years (mean, 58 years), and the exposure time range was 3∼32 years (mean, 22.8 years). The draining pulmonary lymph nodes of 1 case with dust reaction mostly had coal dust deposition, mild pulmonary fibrosis, and local dust fibrosis in the medullary sinus; 1 case of stage I anthracosilicosis mainly showed extensive dust fibrosis and coal dust deposition; 8 cases of stage II anthracosilicosis mainly showed dust fibrosis and silicotic nodules; 1 case of stage III anthracosilicosis and 1 case of stage III silicosis mainly showed silicotic nodules' fusion with each other, and lymph nodes' adhesion and formation of massive fibrosis, and the formation of silicotic nodules was especially obvious in cases of stage III silicosis. The dust lesions of draining pulmonary lymph nodes become severer with higher severity of pulmonary lesions in cases of CWP. The cases of simple silicosis have earlier and severer lesions in draining pulmonary lymph nodes than in lung tissue.

Changes in activities of SOD and GSH-Px in induced sputum and their significance among silicosis patients

To observe the changes in activities of superoxide dismutase (SOD) and glutathione peroxide (GSH-Px) in the induced sputum of silicosis patients, and to investigate the roles of SOD and GSH-Px in the development and progression of silicosis and the significance of measuring activities of SOD and GSH-Px in induced sputum among silicosis patients. Fifty hotel attendants were chosen as control group, 50 workers with more than one year of silica dust exposure as dust exposure group, 32 silica dust-exposed workers as observation subject group, and 52 silicosis patients as silicosis group. The activities of SOD and GSH-Px in their induced sputum were measured by enzyme-linked immunosorbent assay. Compared with the control group, the observation subject group and silicosis group had significantly decreased SOD activity (68.16 ± 30.17 and 66.38 ± 47.32 U/ml vs 75.81 ± 11.92 U/ml, P < 0.05); compared with the dust exposure group, the silicosis group had significantly decreased SOD activity (66.38 ± 47.32 U/ml vs 70.12 ± 14.31 U/ml, P < 0.05). Compared with the control group and dust exposure group, the observation subject group and silicosis group had significantly increased GSH-Px activity (268.21 ± 15.45 and 279.34 ± 29.26 U/ml vs 224.22 ± 12.64 and 236.41 ± 14.54 U/ml, P < 0.05 or P < 0.01). The SOD activity in dust exposure group and silicosis group decreased, but there were no significant differences between patients with different stages of silicosis. The GSH-Px activity in dust exposure group and silicosis group was significantly higher than that in control group, and there were significant differences between patients with different stages of silicosis. These suggest that the imbalance of oxidative/antioxidant systems is associated with the development and progression of silicosis.

The relationship between polymorphisms of epidermal growth factor gene and silicosis

To investigate the relationship between epidermal growth factor (EGF) gene polymorphisms at G-61A, R431K, and D784V and susceptibility to silicosis. In a case-control study, 116 patients diagnosed with stage I silicosis were included in the case group, and 149 workers without silicosis of the same gender and nationality, exposed to the same nature of dust, and with similar age and cumulative time of dust exposure were included in the control group. Peripheral venous blood was collected, DNA was extracted by salting out, polymerase chain reaction-restriction fragment length polymorphism was used to identify the genotypes at three polymorphic loci of EGF and the allele frequencies, and their distributions in the case group and control group were analyzed. The genotype frequencies of G-61A GG, GA, and AA in the case group were 50.9%, 34.5%, and 14.7%, respectively, and significant differences were found when comparing the data with those in the control group (35.6%,44.3%, and 20.1%), (χ(2) = 6.283, P = 0.048). The distribution frequencies of allele A in the case group and control group were 31.9%and 42.3%, respectively, and the difference between the two groups was statistically significant (χ2 = 5.554, P = 0.018). The risk of silicosis in workers carrying allele G at G-61A was increased by 1.564 times (OR = 1.564, 95%CI: 1.092∼2.024). The genotype frequencies of D784V AA, AT, and TT in the case group were 58.6%, 34.5%, and 6.9%, respectively, versus 65.1%, 31.5%, and 3.4% in the control group, and the differences between the two groups were not statistically significant (χ(2) = 2.278, P = 0.320). The genotype frequencies of R431K GG, GA, and AA in the case group were 56.9%, 39.7%, and 3.4%, respectively, versus 55.0%, 39.6%, and 5.4% in the control group, and the differences between the two groups were not statistically significant (χ(2) = 0.572, P = 0.751). The EGF gene polymorphism at G-61A is associated with susceptibility to silicosis, and the risk of silicosis in dust-exposed workers carrying GG genotype is relatively high. No relationship between EGF gene polymorphisms at D784V and R431K and silicosis is found.

Changes of cell factor in bronchoalveolar lavage fluid in rats exposed to silica

To investigate the changes in the levels of inflammatory cytokines in bronchoalveolar lavage fluid (BALF) in rats exposed to silica dust. Experimental rats were randomly divided into control group and three experimental groups (doses of dust: 15, 30, and 60 mg/ml), with 42 rats in each group. Each rat in the control group was treated with 1 ml of normal saline by intratracheal instillation, while each rat in the experimental groups was exposed to 1 ml of silica suspension by a single intratracheal instillation. Seven rats in each group were killed at 1, 3, 7, 14, 21, and 28 days after exposure, and then BALF was collected. Enzyme-linked immunosorbent assay was used to measure the levels of interleukin (IL)-1, IL-6, IL-16, macrophage inflammatory protein-1 alpha (MIP-1α), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), and transforming growth factor-β (TGF-β). The levels of cytokines in each experimental group were higher than those in the control group at any time point. In the early stage of exposure (day 1-3), BALF IL-1 level increased significantly with the increase in dust dose, and on day 14, BALF IL-6 and IL-16 levels increased significantly with the increase in dust dose; the levels of IL-1, IL-6, and IL-16 in the experimental groups reached the peak on day 14. There were significant differences in the levels of MIP-1α and MCP-1 between the experimental groups (FMIP-1α = 30.106, P<0.01; FMCP-1 = 17.193, P<0.01). In each group, the level of MCP-1 varied significantly at different time points (F = 0.618, P>0.05). On day 1-14, BALF TNF-α level increased with the increase in dust dose, with a significant dose-response relationship (P < 0.05). In each experimental group, TNF-α level reached the peak on day 14. On days 14, 21, and 28, the high-dose group had significantly higher BALF TGF-β levels than the low-dose group (P<0.05); on days 14 and 28, the high-dose group had significantly higher BALF TGF-β levels than the middle-dose group (P<0.05). IL-1, IL-6, IL-16, MIP-1α, MCP-1, and TNF-α play a role in the development and progression of silicosis inflammation. TGF-β may be related to (related to; associated with; correlated with) fibrosis.

Clinical analysis of silicosis complicated with spontaneous pneumothorax on silica brick production industry

目的 探讨硅砖生产行业矽肺并发自发性气胸的临床特点及预防思路.方法 对住院治疗的硅砖生产行业矽肺患者79例中并发自发性气胸15例患者的临床资料进行分析.结果 本组硅砖生产行业矽肺自发性气胸的并发率18.99％(15/79);以矽肺Ⅲ期为主14例.左侧气胸3例,右侧气胸8例,双侧气胸4例;闭合型气胸7例,开放型气胸6例,张力型气胸2例;低体重指数(BMI)者15例;低血清白蛋白者14例.15例患者肺复张时间9～86 d,平均30d.治愈13例,好转2例.随访2～0.5年有4例因肺心病、呼吸衰竭死亡.结论 硅砖生产行业矽肺并发自发性气胸的基础疾病重,发生气胸后恢复慢,易复发.建议增加胸部HRCT、BMI及血清白蛋白作为动态观察必检项目。

The long-term therapeutic effects of silicosis by repeat the whole lung lavage

To preliminary study the long term therapeutic effects of repeat the whole lung lavage (RWLL) in the treatment of silicosis. A total of 60 patients with silicosis in the same stone mine were randomly and equally divided into repeat the whole lung Lavage (RWLL) group and whole lung Lavage (WLL) group based on silicosis staging, age and working age of dust exposure. Comparative analysis was performed to evaluate the long-term therapeutic efficacy and safety of RWLL. The cell count and SiO2 content were measured in twice right lung bronchoalveolar lavage fluid(BALF) of the RWLL group. Four years after treatment, the cough and asthma improvement rates of the RWLL group were 68.4% and 75.0% higher than those (52.4%and 57.9%) of the WLL group (P > 0.05). Six years after treatment, the asthma improvement rate (70.0%) of the RWLL group was significantly higher than that (36.8%) of the WLL group (P < 0.05). The RWLL group showed slight decrease in forced vital capacity (FVC) and forced expiratory volume in one second (FEV1.0) after treatment (P > 0.05), while the WLL group showed significant decrease in FVC and FEV1.0 in the six years after treatment (P<0.05). Four and Six years after treatment, the RWLL group had higher no change rate and lower progression rate and significant progression rate than the WLL group in terms of chest X-ray (P>0.05). In the RWLL group,the first time the right lung BALF test showed a number of cells 6.71×10(7)∼2.14×10(9)/L, average 4.50×10(8)/L, pulmonary alveoli macrophages (PAM) ratio of 0.873∼0.980, average 0.954 and SiO2 content of 18∼104.7 mg, average 93.7 mg; the second test showed a number of cells 5.71×10(6)∼1.30×10(9)/L, average 9.12×10(7)/L; PAM ratio 0.710∼0.926, average 0.870 and SiO2 content of 6∼90.2 mg, average 46.2 mg. The RWLL group happened hemoptysis, chest pain one case in perioperative period, the incidence of 6.7%. The RWLL group complicated by left pneumothorax, pulmonary infection one case and the WLL group complicated by one case of lung cancer in a year of follow-up. RWLL is reasonable and safe treatment which could help to further improve the long-term effects of WLL for silicosis.