Whole transcriptome sequencing identifies key lncRNAs,circRNAs, and mRNAs for exploring the pathogenesis and therapeutic target of mouse pneumoconiosis

BACKGROUND

Pneumoconiosis is a kind of lung dysfunction caused by the inhalation of mineral dust. However, the potential molecular mechanism of pneumoconiosis have not been fully elucidated.

METHODS

In this study, the silica-treated pneumoconiosis mice model was constructed and the transcriptome sequencing data including lncRNA, circRNA, and mRNA were obtained. Firstly, differentially expressed lncRNA, circRNA, and mRNA (DElncRNA, DEcircRNA, DEGs) between control and pneumoconiosis/silicosis samples were screened, the target miRNAs (co-pre-miRNAs) were obtained by intersecting the miRNAs predicted by DElncRNA and DEcircRNA, respectively, and the target mRNAs (co-mRNA) were obtained by intersecting the mRNAs predicted by target miRNA and DEGs. Then, the lncRNA/circRNA-miRNA-mRNA networks were constructed by Cytoscape. Next, the key mRNAs were obtained by protein-protein interaction (PPI) analysis, and the key lncRNAs/circRNAs were selected by correlation analysis. Moreover, the expression of the key lncRNAs, circRNAs and mRNAs on chromosome were studied by the "circlize" package. Furthermore, the TFs-miRNA-mRNA network was constructed and the function of DEGs were explored by Ingenuity Pathway Analysis (IPA). To demonstrate the feasibility and value of the constructed ceRNA networks, we validated key genes and mmu-miR-682 pathway. Finally, We used the Drug-Gene Interaction database to predict potential drugs that could interfere with key genes,which may help to find promising treatment.

RESULTS

There were 427 DElncRNAs, 107 DEcircRNAs and 1,597 DEGs between silicosis and control groups. Totals of 77 co-pre-miRNAs and 96 co-mRNA were screened, and the lncRNA/circRNA-miRNA-mRNA networks were constructed with 27 lncRNA/25 circRNAs, 74 miRNAs and 96 mRNAs. Then, 6 key mRNAs including Igf1, Klf4, Ptgs2, Epas1, Gnao1, and Il1a were obtained by PPI, and all of these key mRNAs and 10 key lncRNAs and 8 circRNAs were significantly different between the pneumoconiosis and normal groups, in which 10 lncRNAs and 9 circRNA that have not been previously studied in pneumoconiosis/silicosis can be used as new potential therapeutic targets. Moreover, the TFs-miRNA-mRNA network were constructed with 11 TFs, 1 key miRNA (mmu-miR-682) and 3 key mRNAs (Igf1, Epas1, Ptgs2). And the validation of key genes revealing by RNA-seq through experimental approaches shows the the predictive power of this study. Finally, IPA results indicated that 41 pathways were activated and 2 pathways were suppressed in pneumoconiosis/silicosis groups, and Pathogen Induced Cytokine Storm Signaling Pathway was the most significant pathway affected by pneumoconiosis/silicosis. In addition, 93 drugs were screened out by Drug-Gene Interaction database. Among them, Hydroxychloroquine was a kind of drug which associated with Il1a and Ptgs2, may be a promising treatment.

CONCLUSION

This study constructed the lncRNA/circRNA-miRNA-mRNA and TFs-miRNA-mRNA networks, which could deepen the potential molecular regulatory mechanism of pneumoconiosis/silicosis.

The interplay of Cxcl10+/Mmp14+ monocytes and Ccl3+ neutrophils proactively mediates silica-induced pulmonary fibrosis

As a fatal occupational disease with limited therapeutic options, molecular mechanisms underpinning silicosis are still undefined. Herein, single-cell RNA sequencing of the lung tissue of silicosis mice identified two monocyte subsets, which were characterized by Cxcl10 and Mmp14 and enriched in fibrotic mouse lungs. Both Cxcl10+ and Mmp14+ monocyte subsets exhibited activation of inflammatory marker genes and positive regulation of cytokine production. Another fibrosis-unique neutrophil population characterized by Ccl3 appeared to be related to the pro-fibrotic process, specifically the "inflammatory response". Meanwhile, the proportion of monocytes and neutrophils was significantly higher in the serum of silicosis patients and slices of lung tissue from patients with silicosis further validated the over-expression of Cxcl10 and Mmp14 in monocytes, also Ccl3 in neutrophils, respectively. Mechanically, receptor-ligand interaction analysis identified the crosstalk of Cxcl10+/Mmp14+ monocytes with Ccl3+ neutrophils promoting fibrogenesis via coupling of HBEGF-CD44 and CSF1-CSF1R. In vivo, administration of clodronate liposomes, Cxcl10 or Mmp14 siRNA-loaded liposomes, Ccl3 receptor antagonist BX471, CD44 or CSF1R neutralizing antibodies significantly alleviated silica-induced lung fibrosis. Collectively, these results demonstrate that the newly defined Cxcl10+/Mmp14+ monocytes and Ccl3+ neutrophils participate in the silicosis process and highlight anti-receptor-ligand pair treatment as a potentially effective therapeutic strategy in managing silicosis.

Macrophage-derived exosomal HMGB3 regulates silica-induced pulmonary inflammation by promoting M1 macrophage polarization and recruitment

BACKGROUND

Chronic inflammation and fibrosis are characteristics of silicosis, and the inflammatory mediators involved in silicosis have not been fully elucidated. Recently, macrophage-derived exosomes have been reported to be inflammatory modulators, but their role in silicosis has not been explored. The purpose of the present study was to investigate the role of macrophage-derived exosomal high mobility group box 3 (HMGB3) in silica-induced pulmonary inflammation.

METHODS

The induction of the inflammatory response and the recruitment of monocytes/macrophages were evaluated by immunofluorescence, flow cytometry and transwell assays. The expression of inflammatory cytokines was examined by RT-PCR and ELISA, and the signalling pathways involved were examined by western blot analysis.

RESULTS

HMGB3 expression was increased in exosomes derived from silica-exposed macrophages. Exosomal HMGB3 significantly upregulated the expression of inflammatory cytokines, activated the STAT3/MAPK (ERK1/2 and p38)/NF-κB pathways in monocytes/macrophages, and promoted the migration of these cells by CCR2.

CONCLUSIONS

Exosomal HMGB3 is a proinflammatory modulator of silica-induced inflammation that promotes the inflammatory response and recruitment of monocytes/macrophages by regulating the activation of the STAT3/MAPK/NF-κB/CCR2 pathways.

Psychometric properties of the Perceived Stress Scale (PSS-10) in silica-exposed workers from diverse cultural and linguistic backgrounds

BACKGROUND

The Perceived Stress Scale (PSS-10) has been used in a range of occupational cohorts, but only recently in stone benchtop workers undergoing screening for silicosis. The aim of this study was to compare psychometric properties of the PSS-10 in stone benchtop workers amongst those born overseas or who used an interpreter.

METHODS

Stone benchtop workers in Melbourne, Australia completed the PSS-10 as part of their occupational screening for silicosis. Internal consistency was assessed with Cronbach's α for the total score and the positive and negative subscales. Validity was assessed using confirmatory factor analysis (CFA). Analysis was performed for the total group and for subgroups according to sex, interpreter use, overseas-born, and language spoken at home.

RESULTS

The results of 682 workers with complete PSS-10 scores were included in analysis. Most participants were male (93%), with mean age 36.9 years (SD 11.4), with just over half (51.6%) born in Australia, 10.1% using an interpreter, and 17.5% using a language other than English at home. Cronbach's α for the overall group (α = 0.878) suggested good internal consistency.

DISCUSSION

CFA analysis for validity testing suggested PSS-10 performance was good for both sexes, moderate for country of birth and language spoken at home categories, but poorer for those who used an interpreter. Whilst professional interpreters provide a range of benefits in the clinical setting, the use of translated and validated instruments are important, particularly in cohorts with large numbers of migrant workers.

CONCLUSION

This study describes the psychometric properties of the PSS-10 in a population of stone benchtop workers, with good internal consistency, and mixed performance from validity testing across various subgroups.

Toward targeted treatments for silicosis

PURPOSE OF REVIEW

There has been a rapid increase in silicosis cases, particularly related to artificial stone. The key to management is avoidance of silica exposure. Despite this, many develop progressive disease and there are no routinely recommended treatments. This review provides a summary of the literature pertaining to pharmacological therapies for silicosis and examines the plausibility of success of such treatments given the disease pathogenesis.

RECENT FINDINGS

In-vitro and in-vivo models demonstrate potential efficacy for drugs, which target inflammasomes, cytokines, effector cells, fibrosis, autophagy, and oxidation.

SUMMARY

There is some evidence for potential therapeutic targets in silicosis but limited translation into human studies. Treatment of silicosis likely requires a multimodal approach, and there is considerable cross-talk between pathways; agents that modulate both inflammation, fibrosis, autophagy, and ROS production are likely to be most efficacious.

Early experience of endobronchial ultrasound-guided transbronchial nodal cryobiopsy: a case series from Sabah, Malaysia

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an established minimally invasive method for the diagnosis of benign and malignant conditions. Continuous efforts are underway to improve the material adequacy of EBUS-TBNA, including the introduction of a new technique called EBUS-guided transbronchial nodal cryobiopsy (EBUS-TBNC). This method allows for the retrieval of larger and well-preserved histologic samples from the mediastinum. We present a case series of four patients who underwent combined EBUS-TBNA and EBUS-TBNC procedures in our centre. All procedures were performed under general anaesthesia using a convex probe EBUS scope (Pentax EB-1970UK). Two patients were diagnosed with malignancy and two with benign disorders (silicosis and tuberculosis). In the malignant cases, both EBUS-TBNA/cell block and cryobiopsy provided a diagnosis but cryobiopsy yielded more material for ancillary tests in one patient. However, in the benign cases, there was discordance between EBUS-TBNA/cell block and cryobiopsy. Only cryobiopsy detected granuloma in the patient with TB (tuberculosis), and in the patient with silicosis, TBNC provided a better overall histological evaluation, leading to a definitive diagnosis. No complications were observed. This case series supports the potential diagnostic value of combining EBUS-TBNA and EBUS-TBNC, particularly in benign mediastinal lesions (granulomatous diseases), and in cases requiring additional molecular tests in cancer diagnosis.

[The prevalence of common complications among pneumoconiosis patients: a systematic review and Meta-analysis]

Objective: To analysis the main types and prevalences of complications among pneumoconiosis patients, and to provide scientific basis for the prevention and treatment of pneumoconiosis. Methods: In January 2023, literatures on pneumoconiosis complications published before December 31, 2022 in China National Knowledge Infrastructure (CNKI), Wanfang Database, Chinese Science & Technology Journal Database (VIP), PubMed and Web of Science were systematically searched. Literatures were selected according to inclusion and exclusion criteria, and relevant data were extracted. Quality assessment tool was used to evaluate the quality of the articles for this study. The combined prevalence of complications among pneumoconiosis patients was calculated by R 4.1.1 software. Subgroup analysis was carried out to explore the origin of heterogeneity. Results: Sixty-four eligible articles were selected from 2276 literatures related to pneumoconiosis and its complications. The combined prevalence of complications among pneumoconiosis patients was 21.1% (95% CI: 16.0%-26.3%, I(2)=99.9%). The combined prevalence of chronic obstructive pulmonary disease (COPD) was 26.4% (95%CI: 17.3%-35.6%, I(2)=97.1%), which was the highest among different types of complications among pneumoconiosis patients. Subgroup analyses revealed that the combined prevalence of tuberculosis among pneumoconiosis stage Ⅰ, Ⅱand Ⅲ were 13.8% (95%CI: 10.5%-17.2%, I(2)=99.6%), 18.4% (95% CI: 14.9%-22.0%, I(2)=99.3%) and 37.3% (95% CI: 30.7%-44.0%, I(2)=99.1%), respectively, showing a corresponding increasing tendency (P<0.05). The combined prevalence of tuberculosis among coal worker's pneumoconiosis patients was 12.9% (95% CI: 6.4%-19.3%, I(2)=97.9%), while the combined prevalence of tuberculosis among silicosis patients was 13.9% (95%CI: 10.0%-17.8%, I(2)=96.9%) . Conclusion: The prevalence of pneumoconiosis patients combined with different types of complications is high, and its prevalence increases with the severity of pneumoconiosis.

Biomarkers related to silicosis and pulmonary function in individuals exposed to silica

BACKGROUND

The identification of markers that can facilitate the early diagnosis of silicosis has remained challenging. We evaluated the association of inflammatory markers with the presence of silicosis and lung function impairment in individuals exposed to silica.

METHODS

Individuals exposed and not exposed to silica were assessed by occupational history, clinical findings, lung function, chest imaging findings, and inflammatory markers.

RESULTS

Among 297 men evaluated, 51 were unexposed controls (G1), 149 were exposed to silica without silicosis (G2), and 97 were exposed to silica with silicosis (G3). Inflammatory marker levels were higher in G3 than in G2 and G1. Platelet/lymphocyte ratio (PLR), lactate dehydrogenase (LDH), soluble tumor necrosis factor II (sTNFRII), and macrophage inflammatory protein-4 (MIP-4) were associated with silicosis, and LDH, neutrophil/lymphocyte ratio (NLR), sTNFRII, monocyte chemoattractant protein-1 (MCP-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and fibrinogen were negatively associated with lung function.

CONCLUSION

Blood inflammatory markers are associated with silicosis and impaired lung function.

[Analysis of suspected occupational diseases cases and subsequent diagnosis follow-up investigation in Hubei Province from 2020 to 2021]

Objective: To understand the epidemiological characteristics of suspected occupational diseases cases, and to track the subsequent diagnosis of suspected cases in Hubei Province from 2020 to 2021, and to provide theoretical basis for the supervision of suspected occupational diseases. Methods: In April 2022, the data of suspected occupational diseases cases and occupational diseases in Hubei Province from 2020 to 2021 were collected by the Occupational Diseases and Health Risk Factors Information Surveillance System. The distribution and diagnosis of suspected occupational diseases cases were analyzed. We investigated undiagnosed suspected occupational diseases by telephone. Results: From 2020 to 2021, a total of 1872 cases of suspected occupational diseases in 6 categories and 18 species were reported in Hubei Province. The top three suspected occupational diseases were suspected occupational noise deafness (36.75%, 688/1872), suspected coal worker's pneumoconiosis (33.07%, 619/1872) and suspected silicosis (20.99%, 393/1872). The diagnosis rate of suspected occupational diseases was 33.60% (629/1872). The rate of confirmed diagnosis was 63.59% (400/629). The diagnosis rate (26.86%, 456/1698) and rate of confirmed diagnosis (55.48%, 253/456) of suspected occupational diseases detected by occupational health examination were the lowest. The diagnosis rate of suspected occupational diseases detected by comprehensive medical institutions and private medical institutions were lower than disease prevention and control institutions and occupational disease prevention center (P<0.05). The main reasons for not entering the diagnostic procedure included that workers were not informed that they were diagnosed as suspected occupational diseases (31.55%, 124/393), workers were unwilling to apply for occupational disease diagnosis (18.56%, 73/393), and some workers planned to apply for diagnosis but had not yet applied (10.69%, 42/393) . Conclusion: Occupational noise deafness, coal worker's pneumoconiosis and silicosis are the main diseases of suspected occupational diseases in Hubei Province. In order to increase the diagnosis rate and confirmed diagnosis rate of suspected occupational diseases, it is suggested to strengthen management and supervision from the aspects of case management, information warning and worker notification.

[Expression analysis of inflammatory factors in artificial quartz stone plate processing silicosis patients]

Objective: To investigate the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-1beta (IL-1β) in the plasma and bronchoalveolar lavage fluid of silicosis patients with artificial quartz stone plate processing. Methods: In January 2022, 10 patients with artificial quartz stone plate processing silicosis and 20 patients with common silicosis who were hospitalized and diagnosed in a hospital at Zhejiang Province from June 2019 to December 2021 were retrospectively selected as the research objects, and 30 healthy people were selected as the control group during the same period. Plasma of all subjects and bronchoalveolar lavage fluid of all patients were collected. The levels of TNF-α, IL-6 and IL-1β in plasma and bronchoalveolar lavage fluid were detected by enzyme-linked immunosorbent assay and were analyzed. Results: The levels of TNF-α, IL-6 and IL-1β in the plasma of patients with silicosis were higher than those of the control group (P<0.05), and the levels of TNF-α and IL-1β in the plasma of silicosis patients with artificial quartz stone plate processing were higher than those of common silicosis patients (P<0.05). The levels of TNF-α and IL-1β in plasma of artificial quartz stone plate processing silicosis patients were higher than those of common silicosis patients at the same silicon stage (P<0.05). The levels of IL-1β in bronchoalveolar lavage fluid of silicosis patients with artificial quartz stone plate processing was higher than that of patients with common silicosis (P<0.05) . Conclusion: The levels of TNF-α, IL-6 and IL-1β in silicosis patients with artificial quartz stone plate processing are higher than those in patients with common silicosis, which may be related to dust components they are exposed to.

Fibroblast-derived CXCL14 aggravates crystalline silica-induced pulmonary fibrosis by mediating polarization and recruitment of interstitial macrophages

Exposure to crystalline silica (CS) particles in worksites and dwellings can lead to silicosis due to excessive fibroblast activation. Considering their immuno-regulatory activities, the contribution of pulmonary fibroblasts in the progression of silicosis has not been thoroughly characterized. Here, we demonstrate that exposure of the lung to CS particles leads to the upregulation of fibroblast-derived C-X-C motif chemokine ligand 14 (CXCL14). By employing an in vitro co-culture system, we demonstrated activated fibroblasts recruited bone marrow-derived macrophages (BMDMs) and favored alternative macrophage polarization (M2) mediated by CXCL14. Furthermore, in vivo studies echoed that systemic CXCL14 neutralizing or fibroblast-specific Cxcl14 knockout proved CXCL14 was indispensable for the recruitment and phenotype alteration of lung macrophages, especially interstitial macrophages (IMs), under stimulation by CS particles. Mechanistically, we showed that GLI2 and p21-mediated cellular senescence were mediators of CXCL14 production following CS exposure. Accordingly, GLI2 blockage and countering cellular senescence by reviving PINK1-mediated mitophagy may be efficient strategies to reduce CXCL14 expression in activated fibroblasts during silicosis. Our findings emphasize the immuno-regulatory function of fibroblasts in silicosis via CXCL14, providing intervention targets for CS-induced pulmonary fibrosis.

ISRIB inhibits the senescence of type II pulmonary epithelial cells to alleviate pulmonary fibrosis induced by silica in mice

The role and mechanisms of integrated stress response inhibitor (ISRIB) on silicosis are still not well defined. In the present study, the effects of ISRIB on cellular senescence and pulmonary fibrosis in silicosis were evaluated by RNA sequencing, micro-computed tomography, pulmonary function assessment, histological examination, and Western blot analysis. The results showed that ISRIB significantly reduced the degree of pulmonary fibrosis in mice with silicosis and reduced the expression of type I collagen, fibronectin, α-smooth muscle actin, and transforming growth factor-β1. Both in vivo and in vitro results showed that ISRIB reversed the expression of senescence-related factors β-galactosidase, phosphor-ataxia telangiectasia mutated, phosphor-ataxia telangiectasia and Rad3-related protein, p-p53, p21, p16, and plasminogen activator inhibitor type 1. The aforementioned results were consistent with the sequencing results. These findings implied that ISRIB might reduce the degree of pulmonary fibrosis in mice with silicosis by inhibiting the cellular senescence of alveolar epithelial cell type II.

Ac-SDKP promotes KIF3A-mediated β-catenin suppression through a ciliary mechanism to constrain silica-induced epithelial-myofibroblast transition

Kinesin family member 3 A (KIF3A) decrease have been reported in silicotic patients and rats. However, the detailed mechanisms of KIF3A in silicosis remain unknown. In this study, we demonstrated that KIF3A effectively blocked the expression of β-catenin and downstream myocardin-related transcription factor (MRTF)-A/serum response factor (SRF) signaling, thus inhibiting silica-induced epithelial-myofibroblast transition (EMyT). Moreover, KIF3A was identified as a downstream mediator of an antifibrotic tetrapeptide N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP). Knockdown of KIF3A expression reactivated β-catenin/myocardin-related transcription factor (MRTF)-A/serum response factor (SRF) signaling that was attenuated by Ac-SDKP in vitro. Collectively, our findings suggest that Ac-SDKP plays its anti-fibrosis role via KIF3A-mediated β-catenin suppression, at least in part, in both in vivo model of silicosis and in vitro model of EMyT.

Association of spirometric restriction with mortality in the silicotics: a cohort study

BACKGROUND

Restrictive spirometry pattern (RSP), defined as reduced forced vital capacity (FVC) in absence of airflow obstruction (AFO), is associated with increased risk of mortality in general population. However, evidence in the patients with silicosis is limited. This study was aimed to investigate the relationship between RSP and the risk of death in a silicotic cohort.

METHOD

This retrospective cohort study used data from the Pneumoconiosis Clinic, Hong Kong Department of Health that containing 4315 patients aged 18-80 years and diagnosed with silicosis during 1981-2019, with a follow-up till 31 December 2019. Spirometry was carried out at the diagnostic examination of silicosis. Lung function categories were classified as normal spirometry (FEV1/FVC ≥ 0.7, FVC ≥ 80% predicted), RSP only (FEV1/FVC ≥ 0.7, FVC < 80% predicted), AFO only (FEV1/FVC < 0.7, FVC ≥ 80% predicted), and RSP&AFO mixed (FEV1/FVC < 0.7, FVC < 80% predicted). The hazard ratio (HR) and 95% confidence intervals (95% CI) were computed using a Cox proportional hazards model adjusting for age, body mass index, history of tuberculosis, smoking status, pack-years, and radiographic characteristics of silicotic nodules.

RESULTS

Among the 4315 patients enrolled in the study, the prevalence of RSP was 24.1% (n = 1038), including 11.0% (n = 473) with RSP only and 13.1% (n = 565) with mixed RSP and AFO. During the follow-up period, a total of 2399 (55.6%) deaths were observed. Compared with the silicotics with normal spirometry, those with RSP only had significantly increased risk of all-cause mortality (HR = 1.63, 95% CI 1.44-1.85) and respiratory-related mortality (HR = 1.56, 95% CI 1.31-1.85). Notably, a higher risk of mortality was observed in silicotics with mixed ventilatory defects of both RSP and AFO (all-cause mortality: HR = 2.22, 95% CI 1.95-2.52; respiratory-related mortality: HR = 2.59, 95% CI 2.18-3.07) than in those with RSP only.

CONCLUSION

RSP is significantly associated with increased risk of all-cause and respiratory-related mortality in the silicotics, and patients with mixed restrictive and obstructive ventilatory defect have higher risk of mortality than those with single RSP or AFO. These findings emphasize the importance of recognizing RSP in the occupational settings, especially for the silicotic patients with mixed ventilatory defect.

[The characteristics of plasma lipids in silicosis rat models were studied based on lipid metabolomics]

Objective: To screen the differential metabolites and metabolic pathways in silicosis model by analyzing plasma metabolomics of silicosis rats. Methods: In May 2021, twenty male SD rats were randomly divided into control group (C), 1-week silicosis group (S1W), 2-week silicosis group (S2W) and 4-week silicosis group (S4W), with 5 rats in each group. Rats were intratracheally instillated with 1ml crystalline SiO(2) suspension (50 mg/ml) or normal saline and were sacrificed after 1 week, 2 weeks and 4 weeks, HE staining was used to observe the lung pathology of rats. The plasma samples were analyzed by UPLC-IMS-QTOF mass spectrometer to screen out potential differential metabolites in silicosis models and analyze their lipid enrichment. Results: HE results showed that nodules formed in the silicosis model group, and with the extension of time, nodules gradually increased and alveolar structure was gradually destroyed. Metabolomics screened out 14 differential metabolites in S1W, 24 in S2W, and 28 in S4W, and found that the differential metabolites were mainly enriched in the metabolism of glycerophospholipid metabolism, fatty acid degradation, Glycosylphosphatidylinositol (GPI) -anchor biosynthesis, fatty acid elongation and other metabolic pathways. Conclusion: There are significant changes in plasma lipid metabolites in silicosis rat models.

Cholesterol-dependent molecular mechanisms contribute to cationic amphiphilic drugs' prevention of silica-induced inflammation

Silicosis is considered an irreversible chronic inflammatory disease caused by the inhalation of crystalline silica (cSiO2). The cycle of inflammation that drives silicosis and other particle-caused respiratory diseases is mediated by NLRP3 inflammasome activity in macrophages resulting in the release of IL-1β. Lysosomal membrane permeability (LMP) initiated by inhaled particles is the key regulatory step in leading to NLRP3 activity. In addition to its role in LMP, the lysosome is crucial to cellular cholesterol trafficking. Lysosomal cholesterol has been demonstrated to regulate LMP while cationic amphiphilic drugs (CADs) reduce cholesterol trafficking from lysosomes and promote endolysosomal cholesterol accumulation as seen in Niemann Pick disease. Using a bone marrow derived macrophage (BMdM) model, four CADs were examined for their potential to reduce cSiO2-induced inflammation. Here we found that FDA-approved CAD drugs imipramine, hydroxychloroquine, fluvoxamine, and fluoxetine contributed to reduced LMP and IL-1β release in cSiO2 treated BMdM. These drugs inhibited lysosomal enzymatic activity of acid sphingomyelinase, decreased lysosomal proteolytic function, and increased lysosomal pH. CADs also demonstrated a significant increase in lysosomal-associated free cholesterol. Increased lysosomal cholesterol was associated with a significant reduction in cSiO2 induced LMP and IL-1β release. In contrast, reduced lysosomal cholesterol significantly exacerbated cSiO2-induced IL-1β release and reduced the protective effect of CADs on IL-1β release following cSiO2 exposure. Taken together, these results suggest that CAD modification of lysosomal cholesterol may be used to reduce LMP and cSiO2-induced inflammation and could prove an effective therapeutic for silicosis and other particle-caused respiratory diseases.

A systematic review of the effectiveness of dust control measures adopted to reduce workplace exposure

The recent increase in silicosis cases in several countries casts doubt on dust control practices and their effectiveness in preventing respirable crystalline silica (RCS) exposure. Apart from silicosis, RCS may lead to other illnesses, health-related quality of life losses for workers and their families, and economic losses for companies. Thus, this systematic literature review examined the effectiveness of interventions employed to prevent exposure to RCS and increase the use of dust control measures. The review used keywords related to dust control interventions to search seven databases. Search results were screened and extracted for synthesis. The narrative synthesis showed the extent of research investment in China. In several designs and combinations, the interventions utilized water, surfactant, foam, and air currents to reduce dust exposure. These interventions offer varying degrees of dust control effectiveness against RCS and respirable dust. Although evidence indicates that interventions significantly decrease dust concentration levels, the control measures in place may not effectively prevent workplace overexposure to RCS. The review found that education and training interventions are employed to improve dust controls and respiratory protective equipment (RPE) use. Also, marketing strategies promote the use of RPE. These interventions can increase the frequency of use of RPE and the adoption of best practice dust control measures. Interventions increase knowledge, awareness, and attitudes about RPE usage and generate positive perceptions while reducing misconceptions. However, the benefits obtained from an intervention may diminish after its implementation, indicating that the interventions may not continually motivate workers to adopt control measures or use RPE.

[Epidemiological Characteristics and Drug Resistance of Microbial Pathogens of Patients With Silicosis Combined With Pulmonary Infection]

Objective

To investigate the epidemiological characteristics of patients with silicosis combined with pulmonary infection in recent years, to study the distribution and the drug susceptibility of fungal and bacterial pathogens in their sputum samples, and to provide references for the prevention and treatment of silicosis and the appropriate drug use.

Methods

The clinical data and drug sensitivity test results of patients with silicosis combined with pulmonary infection diagnosed at the Department of Occupational Diseases, West China Fourth Hospital, Sichuan University were retrospectively analyzed.

Results

A total of 318 patients with silicosis combined with pulmonary infection who received treatment between January 2017 and December 2020 were enrolled. All the patients had positive microorganism test results. All participants were male. Their median age at the time of onset was 51.00 years and the median time of exposure to silica dust at work was 12.40 years. They worked mostly in construction, non-ferrous metal mining, and coal mining. The main types of work they did were pneumatic drilling, coal digging, and mining. The positive detection rates for the first, second and third phases of silicosis were 27.54%, 28.32%, and 32.97%, respectively. A total of 341 strains of fungal and bacterial pathogens were isolated, of which, 54.1% were fungi, including 114 strains (35.8%) of Candida albicans, and 53.1% were bacteria, including 168 strains (52.8%) of gram-negative bacteria, most of which being Klebsiella pneumoniae (30.2%). There was only 1 strain (0.3%) of gram-positive bacteria, namely Staphylococcus hemolyticus. Gram-negative bacilli were most resistant to ampicillin and highly sensitive to penicillin G and ofloxacin.

Conclusion

Among patients with silicosis combined with pulmonary infection, the incidence of pulmonary infection increases along with the progress of silicosis. Microorganism analysis reveals high detection rates for fungi and the bacteria detected are predominantly gram-negative bacteria. The overall prospect for drug resistance rate was not optimistic.

Evaluation of Oxidative Stress Parameters and Genotoxic Effects in Patients With Work-Related Asthma and Silicosis

OBJECTIVE

To determine the mechanistic roles of oxidative stress, inflammation, and genotoxicity parameters in patients with work-related asthma (WRA) and silicosis.

METHODS

Thirty-eight healthy office workers, 27 employees with a history of exposure and no disease, 24 employees with WRA, and 23 employees with silicosis were included in this study. Superoxide dismutase, catalase, glutathione peroxidase, malondialdehyde, and interleukins (IL) 17, 23, and 27 levels were measured in the serum. Genotoxic damage was evaluated by calculating the frequency of micronuclei in swab samples and 8-hydroxy-2'-deoxyguanosine in serum.

RESULTS

Serum superoxide dismutase, catalase, glutathione peroxidase, malondialdehyde, 8-hydroxy-2'-deoxyguanosine, and IL-17, IL-23, and IL-27 levels were found to be statistically significantly higher in the exposure, WRA, and silicosis groups compared with the control group. The frequency of micronuclei in buccal epithelial cells of the patient group was found to be significantly higher than that of the control group.

CONCLUSION

These results may provide information for molecular mechanisms and early diagnosis of WRA and silicosis and will be a guide for taking precautions in the early period.

Silica crystals activate toll-like receptors and inflammasomes to promote local and systemic immune responses in zebrafish

Silica crystals are potent activators of the inflammasome that cause a fibrotic lung disease, called silicosis, with no effective treatment available. We report here that injection of silica crystals into the hindbrain ventricle of zebrafish embryos led to the initiation of local and systemic immune responses driven through both Toll-like receptors (TLR)- and inflammasome-dependent signaling pathways, followed by induction of pro-fibrotic markers. Genetic and pharmacological analysis revealed that the Nlrp3 inflammasome regulated silica crystal-induced inflammation and pyroptotic cell death, but not emergency myelopoiesis. In addition, Cxcl8a/Cxcr2-dependent recruitment of myeloid cells to silica crystals was required to promote emergency myelopoiesis and systemic inflammation. The zebrafish model of silicosis developed here shed light onto the molecular mechanisms involved in the activation of the immune system by silica crystals.

About the Transient Effects of Synthetic Amorphous Silica: An In Vitro Study on Macrophages

Silica (either crystalline or amorphous) is widely used for different applications and its toxicological assessment depends on its characteristics and intended use. As sustained inflammation induced by crystalline silica is at the root of silicosis, investigating the inflammatory effects induced by amorphous silicas and their persistence is needed. For the development of new grades of synthetic amorphous silicas, it is also desirable to be able to understand better the factors underlying potential adverse effects. Therefore, we used an optimized in vitro macrophage system to investigate the effects of amorphous silicas, and their persistence. By using different amorphous silicas, we demonstrated that the main driver for the adverse effects is a low size of the overall particle/agglomerate; the second driver being a low size of the primary particle. We also demonstrated that the effects were transient. By using silicon dosage in cells, we showed that the transient effects are coupled with a decrease of intracellular silicon levels over time after exposure. To further investigate this phenomenon, a mild enzymatic cell lysis allowed us to show that amorphous silicas are degraded in macrophages over time, explaining the decrease in silicon content and thus the transiency of the effects of amorphous silicas on macrophages.

Hazardous dusts from the fabrication of countertop: a review

Artificial countertop materials, including solid surface composites (SSC) and engineered stone (ES) may pose significant pulmonary health risks for workers who manipulate them. These materials have rapidly become popular in the multibillion-dollar countertop industry, rivaling that of natural materials such as granite and marble due to their variety of desirable esthetic qualities and reduced costs. Both SSC and ES consist of a mineral substrate bound together in a polymer matrix. For SSC the mineral is about 70% aluminum trihydrate (ATH) while ES contains up to 95% crystalline silica by weight. Both materials emit airborne dusts when being manipulated with power tools during the fabrication process. Several deaths and dozens of cases of silicosis have been identified worldwide in workers who fabricate ES, while a single case of fatal pulmonary fibrosis has been associated with SCC dust exposure. This review examines the current state of knowledge for both SSC and ES regarding the composition, particle emission characteristics, workplace exposure data, particle constituent toxicity, and possible methods for reducing worker exposure.

Physical and chemical properties of dust in the Pre-Aral region of Uzbekistan

The aim of this work is study of physical and chemical properties of dust of the Pre-Aral region of Uzbekistan such as Karakalpakstan and Khorezm that are located near the three deserts such as the Aralkum, Karakum, and Kyzylkum. The dust particles fell on glass have been collected in Karakalpakstan and Khorezm and studied systematically by employing wide range of methods. Particle volume vs size distribution has been measured with maximum around 600 nm and ~ 10 µm. The major and minor constituent materials present in the dust have been studied systematically by X-ray fluorescence spectroscopy, energy dispersive X-ray diffraction, and inductively coupled plasma optical emission spectroscopy. Main characteristic absorption bands corresponding to Si-O, Si-O-Si bonding in quartz and Fe-O bonds in hematite Fe₂O₃ have been identified by infrared and Raman spectroscopy. Quartz, hematite, lime, corundum, magnesia, and several other trace minerals have been identified in the dust particles. X-ray diffraction peaks corresponding to quartz, hematite, and corundum are sharp and are found to be more crystalline with some level of disorder. Analysis of the particle size and crystallinity on human being has been performed: disordered or crystalline quartz can create the lung disease; the particles in the size of 0.5-0.7 µm may produce diseases such as chronic silicosis, silicosis, and silica tuberculosis whereas hematite might create lung disease. Dust particles worsen optical transmittance of glass of the panels.

[Analysis on incidence of occupational diseases in Guangzhou from 2010 to 2020]

Objective: To analyze the incidence characteristics of occupational diseases in Guangzhou from 2010 to 2020, provide scientific basis for formulating occupational disease prevention and control policies. Methods: In January 2021, based on the data of occupational diseases in Guangzhou reported in the Information Monitoring System of Occupational Diseases and Occupational Health, descriptive epidemiological method was used to analyze the types and characteristics of occupational diseases in Guangzhou from 2010 to 2020. Results: A total of 1341 cases of 38 kinds of occupational diseases in 9 categories were reported in the past 11 years. The incidence of occupational pneumoconiosis, occupational otolaryngology and oral diseases and occupational chemical poisoning ranked the top three, accounting for 38.1% (511/1341) , 30.5% (409/1341) and 16.2% (217/1341) of the total cases respectively. The cases of pneumoconiosis in welders and silicosis accounted for 47.7% (244/511) and 34.4% (176/511) of the cases of occupational pneumoconiosis respectively. The cases of noise deafness accounted for 99.8% (408/409) of occupational otorhinolaryngology oral diseases. Acute occupational chemical poisoning cases accounted for 26.7% (58/217) of the occupational chemical poisoning cases, in which dichloroethane poisoning cases ranked the first, accounting for 79.3% (46/58) . Chronic occupational chemical poisoning cases accounted for 73.3% (159/217) of the occupational poisoning cases, in which benzene and lead poisoning cases ranked the top two, accounting for 79.2% (126/159) and 17.6% (28/159) respectively. Conclusion: Pneumoconiosis, silicosis, noise deafness, benzene poisoning, lead poisoning, dichloroethane poisoning should be supervised and managed as key occupational diseases in Guangzhou.

[Analysis on the diagnosis of suspected occupational diseases in Guangzhou from 2014 to 2019]

Objective: To understand the diagnosis of suspected occupational diseases reported in Guangzhou from 2014 to 2019, so as to provide theoretical basis and technical support for the supervision of suspected occupational disease reports. Methods: By cluster sampling, the suspected occupational disease report card, occupational disease report card and pneumoconiosis report card reported by Guangzhou from January 1, 2014 to December 31, 2019 in the occupational disease and occupational health information monitoring system were collected for matching analysis to understand the diagnosis of suspected occupational disease patients. Results: From 2014 to 2019, a total of 1426 suspected occupational cases in 7 categories and 32 species were reported in Guangzhou. The average number of reported cases per year was about 240. The main diseases of suspected occupational diseases were suspected occupational noise deafness (68.44%, 976/1426) , suspected occupational chronic benzene poisoning (16.48%, 235/1426) , suspected occupational other pneumoconiosis (4.84%, 69/1426) , suspected occupational silicosis (3.23%, 46/1426) and suspected occupational welder pneumoconiosis (1.82%, 26/1426) . The diagnostic rate required to enter the occupational disease diagnostic program is 36.61% (522/1426) , and the diagnostic rate is 59.20% (309/522) . In 2019, the diagnosis rate of suspected occupational diseases was the lowest (23.92%, 61/255) , Huadu District was the lowest (8.33%, 9/108) , suspected occupational pneumoconiosis was the lowest (28.03%, 44/157) , the diagnosis rate of suspected occupational diseases reported by the Centers for Disease control and prevention was the lowest (17.43%, 19/109) , and the diagnosis rate of suspected occupational diseases reported by outpatient treatment was the lowest (22.22%, 2/9) . The suspected occupational diseases reported by institutions outside Guangzhou did not enter the occupational disease diagnosis procedure. Suspected occupational skin diseases, suspected occupational diseases caused by physical factors and suspected occupational tumors were diagnosed, and the diagnosis rate of occupational disease prevention and control institutions was the highest (94.87%, 37/39) . Conclusion: The main types of suspected occupational diseases reported during these six years are noise deafness, chronic benzene poisoning and pneumoconiosis. The overall diagnosis rate and diagnosis rate of suspected occupational diseases are not high. It is suggested to improve the network direct reporting system of suspected occupational diseases and strengthen the follow-up management and supervision of suspected occupational diseases.

Silica Exposure Estimates in Artificial Stone Benchtop Fabrication and Adverse Respiratory Outcomes

Silicosis is being increasingly reported among young stonemasons in the artificial stone (AS) benchtop fabrication and installation industry. Respiratory health screening, which included a job and exposure history, a chest X-ray (CXR), a respiratory health questionnaire, and gas transfer testing, were offered to stonemasons in Victoria, Australia. Workers typically reported a variety of tasks, including cleaning and labouring, which made exposure assessment complex. We estimated the relative respirable crystalline silica exposure intensity of each job from the proportion of time using AS and the proportion of time doing dry work (work without water suppression). The relative average intensity of exposure for up to five jobs was calculated. Cumulative exposure was calculated as the sum of the duration multiplied by intensity for each job. Installers and factory machinists (other than computer numeric control operators) were the most likely to report dry work with AS, and so had a greater average intensity of exposure. Exposure intensity and cumulative exposure were associated with increased odds of an ILO (International Labour Organisation) CXR profusion major category of ≥1 and with dyspnoea. Exposure duration was also associated with ILO profusion category. In multivariate analyses of health outcomes, only job type was associated with the ILO profusion category. For both most recent and longest-duration job types, when compared to the lowest exposure group, factory machinists were more likely to have an ILO category ≥1. This suggests that intensity of exposure estimated from the proportion of time dry cutting and proportion of time working on AS can predict the risk of adverse respiratory outcomes for workers in this industry.

PPARγ/LXRα axis mediated phenotypic plasticity of lung fibroblasts in silica-induced experimental silicosis

Silicosis is a disease mainly caused by pulmonary interstitial fibrosis caused by long-term inhalation of dust with excessively high content of free SiO₂. Transdifferentiation of lung fibroblasts into myofibroblasts is an important cellular basis for silicosis, but the key transcription factors (TFs) involved in this process are still unclear. In order to explore the biological regulation of transcription factor PPARγ/LXRα in silica-induced pulmonary fibrosis, this study explored the molecular mechanism of PPARγ/LXRα involved in regulating transcription factors related to SiO₂-induced lung injury at the cellular level and in animal models. ChIP-qPCR detected that PPARγ directly regulated the transcriptional activity of the LXRα gene promoter, while the PPARγ agonist RSG increased the expression of LXRα. In addition, we demonstrated in the cell model that upregulation of LXRα can inhibit silica-mediated fibroblast transdifferentiation, accompanied by an increase in the expression of SREBF1, PLTP and ABCA1. The results of LXRα silencing experiment matched those of overexpression experiment. These studies explored the role of LXRα in plasticity and phenotypic transformation between lung fibroblasts and myofibroblasts. Therefore, inhibiting or reversing the transdifferentiation of lung fibroblasts to myofibroblasts by intervening PPARγ/LXRα may provide a new therapeutic target for the treatment of silicosis.

Plasma Metabolic Profiling in Patients With Silicosis and Asbestosis

OBJECTIVES

To explore the circulating metabolites and related pathways in silicosis and asbestosis exposure to different mineral dust.

METHODS

Plasma of 30 silicosis, 30 asbestosis, and 20 healthy controls was analyzed using liquid chromatography-mass spectrometry. Metabolic networks and the relevance of the identified metabolic derangements were explored.

RESULTS

Compared with healthy controls, 37 and 39 dysregulated plasma metabolites were found in silicosis and asbestosis, respectively, of which the levels of 22 metabolites differed. Three major pathways were identified, among which arginine and proline metabolism was identified as the most closely related metabolic pathway.

CONCLUSIONS

The types and quantities of up-regulated metabolites including lipids, amino acids, and carnitines differed between silicosis and asbestosis. Pathways inducing lung fibrosis were common to mineral dust exposure, while pathways related to oxidative stress and tumorigenesis differed between silicosis and asbestosis.

Using Artificial Intelligence for High-Volume Identification of Silicosis and Tuberculosis: A Bio-Ethics Approach

Although Artificial Intelligence (AI) is being increasingly applied, considerable distrust about introducing "disruptive" technologies persists. Intrinsic and contextual factors influencing where and how such innovations are introduced therefore require careful scrutiny to ensure that health equity is promoted. To illustrate one such critical approach, we describe and appraise an AI application - the development of computer assisted diagnosis (CAD) to support more efficient adjudication of compensation claims from former gold miners with occupational lung disease in Southern Africa. In doing so, we apply a bio-ethical lens that considers the principles of beneficence, non-maleficence, autonomy and justice and add explicability as a core principle. We draw on the AI literature, our research on CAD validation and process efficiency, as well as apprehensions of users and stakeholders. Issues of concern included AI accuracy, biased training of AI systems, data privacy, impact on human skill development, transparency and accountability in AI use, as well as intellectual property ownership. We discuss ways in which each of these potential obstacles to successful use of CAD could be mitigated. We conclude that efforts to overcoming technical challenges in applying AI must be accompanied from the onset by attention to ensuring its ethical use.

Mortality in Underground Miners in a Former Uranium Ore Mine–Results of a Cohort Study Among Former Employees of Wismut AG in Saxony and Thuringia

BACKGROUND

From 1946 to 1990, more than 400 000 people were employed by Wismut AG, a Soviet/Soviet-German corporation (German abbreviation: SAG/ SDAG), in the East German states of Saxony and Thuringia. In the early years in particular, employees were exposed to large amounts of radon and respirable crystalline silica.

METHODS

In a cohort of 35 204 former underground employees of Wismut AG, mortality was analyzed in comparison to the general male population of East Germany, and the pertaining standardized mortality ratios (SMRs) were calculated.

RESULTS

18 510 persons in the study cohort died in the follow-up period 1960-2013. Mortality from lung cancer was 2.36 higher in the study cohort than in the general population (95% confidence interval, [2.28; 2.45]); the associated SMRs rose markedly with increasing radon exposure. Mortality from silicosis and other types of pneumoconiosis was elevated by a factor of 22.62 [21.20; 24.11], and the associated SMRs rose exponentially with increasing exposure to respirable crystalline silica. Mortality from both of these causes was still markedly elevated more than 20 years after Wismut AG had ceased its activities. Mortality from a wide range of other diseases was elevated as well, with the following SMRs: stomach cancer, 1.28 [1.17; 1.40]; liver cancer, 1.34 [1.15; 1.55]; all tumors other than lung cancer, 1.06 [1.02; 1.09]; infections, 1.18 [1.01; 1.38]; cerebrovascular diseases, 1.33 [1.26; 1.41]; and influenza/pneumonia, 1.13 [1.01; 1.27]. Mortality from a small number of other causes was found to be markedly lowered in the study cohort (mental illness, renal diseases, and nervous system diseases). The role of occupational risk factors, lifestyle differences and other reasons for the latter results is unclear.

CONCLUSION

Underground miners employed by Wismut AG displayed marked excess mortality due to silicosis/other pneumoconiosis and lung cancer. The contribution of individual occupational risk factors for these and other causes of death with increased SMR are being further investigated in analyses within the study cohort.

Analysis of Health Service Utilization and its Influencing Factors among Patients with Pneumoconiosis in China

Pneumoconiosis, an interstitial lung disease that occurs from breathing in certain kinds of damaging dust particles, is a major occupational disease in China. Patients diagnosed with occupational pneumoconiosis can avail of free medical treatment, whereas patients without a diagnosis of occupational diseases cannot not claim free medical treatment in most provinces from the government before 2019. This study aimed to analyze the priority of medical facility selection and its influencing factors among patients with pneumoconiosis. A total of 1,037 patients with pneumoconiosis from nine provinces in China were investigated. The health service institutions most frequently selected by the patients were county-level hospitals (37.5%). The main reason for the choice was these hospitals' close distance to the patients' homes (47.3%). The factors for the choice of health care institutions were living in the eastern region ( OR = 2.91), living in rural areas ( OR = 2.10), silicosis diagnosis ( OR = 2.44), employment in private enterprises ( OR = 2.91), smoking ( OR = 2.69), and quit smoking ( OR = 3.98). The diagnosis, treatment, and rehabilitation therapy of pneumoconiosis should be enhanced in primary medical institutions.

Transcriptome analysis reveals a protective role of liver X receptor alpha against silica particle-induced experimental silicosis

Silicosis, a severe and irreversible form of pulmonary fibrosis (PF) caused by long-term exposure to dust particles in production environments, is the biggest occupational health concern in China and most low-income countries. The transdifferentiation of pulmonary fibroblasts is the terminal event in silicosis, and specific transcription factors (TFs) play a crucial role in this condition. However, the relationship between TF-mediated regulation and silicosis remains unknown. We performed a transcriptomic analysis to elucidate this relationship, and our results revealed that two TFs, EGR2 and BHLHE40, were upregulated and five, i.e., TBX2, NR1H3 (LXRα), NR2F1, PPARG (PPARγ), and EPAS1, were downregulated in activated fibroblasts. Notably, PPARγ and LXRα expression was also decreased in an experimental mouse model of silicosis. The mechanism underlying these changes may involve TGF-β1 secretion from silica-exposed alveolar macrophages, causing PPARγ and LXRα downregulation, which in turn would result in aberrant α-SMA transcription. Our results suggest that LXRα is a potential target for the prevention of silicosis and PF.

Silicosis in finishing workers in quartz conglomerates processing

INTRODUCTION

Outbreaks of silicosis have bene recently reported in artificial stone workers.

AIM

To describe the features of silicosis in quartz conglomerate workers in North-Eastern Italy.

METHODS

Active search of pneumoconiosis was performed in 11 companies of North-Eastern Italy involved in the fabrication of quartz conglomerate countertops. Occupational history, lung function tests, chest X-ray and high resolution computed tomography (HRCT) were performed. In selected cases, trans-bronchial biopsies were taken for histological evaluation and identification of silica crystals in the tissue. Cumulative exposure to crystalline silica was estimated.

RESULTS

We recruited 45 workers and 24 cases of silicosis were diagnosed. Mean age at diagnosis was 43 years and duration of exposure to quartz conglomerate dust was 3.5 to 20 years. The average silica cumulative exposure was 4.3 mg/m3/y. Abnormal findings were detected in 42% of chest X-rays, in 33% of spirometry and 50% of carbon monoxide lung diffusion (DLco). HRCTs were abnormal in all cases showing well-defined rounded opacities, irregular/linear intralobular opacities and bilateral enlarged mediastinal lymph-nodes. Histological findings consistent with silicosis were observed in 24 cases. Numerous silica particles (diameter 0.1-5 µm) were identified in lung tissue.

CONCLUSIONS

We reported an unexpected high incidence of silicosis in Italian workers exposed to quartz conglomerate dust. The results suggest that chest HRCT is indicated for screening of workers with high exposure to silica and DLco should be added to spirometry in health surveillance. More rigorous application of safety regulations and more effective preventive interventions at work are necessary.

Public Health 2019, 16 (4), 568, doi:10.3390/ijerph16040568

The systematic review by Leso et al. (16 February 2019) is a timely contribution to the body of knowledge concerning silicosis. It highlights the lack of quality data necessary to inform both occupational health risk management and the clinical management of workers exposed to respirable crystalline silica. This communication highlights current activity being undertaken in Queensland, Australia, that will further inform our knowledge concerning this entirely preventable disease. We are about half-way through a government-funded, case-finding program involving over 800 workers from the engineered stone bench-top fabrication industry. As of 15 February 2019, 99 confirmed cases of silicosis associated with engineered stone work were identified; nearly all were asymptomatic. The empirically observed false negative rate of ILO CXRs in this high-risk group appeared significantly greater than 10%. From pooled data, we hope to develop an appropriate index of exposure to trigger health surveillance using low-dose chest HRCT. Once a worker develops symptoms of silicosis, apart from lung transplantation, there are no treatment options currently available.

Overview of Silica-Related Clusters in the United States: Will Fracking Operations Become the Next Cluster?

Silicosis is the oldest know occupational pulmonary disease. It is a progressive disease and any level of exposure to respirable crystalline silica particles or dust has the potential to develop into silicosis. Silicosis is caused by silica particles or dust entering the lungs and damaging healthy lung tissue. The damage restricts the ability to breathe. Exposure to silica increases a worker’s risk of developing cancer or tuberculosis. This special report will provide background history of silicosis in the U.S., including the number of workers affected and their common industries. Over the years, these industries have impeded government oversight, resulting in silicosis exposure clusters. The risk of acquiring silicosis is diminished when industry implements safety measures with oversight by governmental agencies. Reputable authorities believe that the current innovative drilling techniques such as fracking will generate future cases of silicosis in the U.S. if safety measures to protect workers are ignored.

Leveraging Big Data for Exploring Occupational Diseases-Related Interest at the Level of Scientific Community, Media Coverage and Novel Data Streams: The Example of Silicosis as a Pilot Study

Objective

Silicosis is an untreatable but preventable occupational disease, caused by exposure to silica. It can progressively evolve to lung impairment, respiratory failure and death, even after exposure has ceased. However, little is known about occupational diseases-related interest at the level of scientific community, media coverage and web behavior. This article aims at filling in this gap of knowledge, taking the silicosis as a case study.

Methods

We investigated silicosis-related web-activities using Google Trends (GT) for capturing the Internet behavior worldwide in the years 2004–2015. GT-generated data were, then, compared with the silicosis-related scientific production (i.e., PubMed and Google Scholar), the media coverage (i.e., Google news), the Wikipedia traffic (i.e, Wikitrends) and the usage of new media (i.e., YouTube and Twitter).

Results

A peak in silicosis-related web searches was noticed in 2010–2011: interestingly, both scientific articles production and media coverage markedly increased after these years in a statistically significant way. The public interest and the level of the public engagement were witnessed by an increase in likes, comments, hashtags, and re-tweets. However, it was found that only a small fraction of the posted/uploaded material contained accurate scientific information.

Conclusions

GT could be useful to assess the reaction of the public and the level of public engagement both to novel risk-factors associated to occupational diseases, and possibly related changes in disease natural history, and to the effectiveness of preventive workplace practices and legislative measures adopted to improve occupational health. Further, occupational clinicians should become aware of the topics most frequently searched by patients and proactively address these concerns during the medical examination. Institutional bodies and organisms should be more present and active in digital tools and media to disseminate and communicate scientifically accurate information. This manuscript should be intended as preliminary, exploratory communication, paving the way for further studies.

[Research on the Anti-Pulmonary Fibrosis Effect of the Bletilla striata Polysaccharide in Rat Silicosis Model]

OBJECTIVE

To investigate the anti-pulmonary fibrosis effect and the possible molecular mechanism of the Bletilla striata polysaccharide.

METHODS

Polysaccharide was prepared by water reflux extraction plus ethanol precipitation method, and following deproteinization process by Sevage method. Rat silicosis model was established by invasive intratracheal instillation method. The effect and molecular mechanism of the polysaccharide was evaluated by lung indexes, lung pathological change, serum levels of SOD,MDA,NF-κB,IL-1β,PDGF,TGF-β1,TNF-α,HYP were detected, and the contents of CD3~+,CD4~+,CD8~+T lymph cells and CD4~+/ CD8~+ratio were detected by flow cytometry.

RESULTS

Both low( 100 mg / kg) and high( 400 mg / kg) dosage polysaccharide treatment could remarkably elevate the serum SOD level and reduce the MDA,NO level, and effectively reverse the CD4~+/ CD8~+ratio comparing with the model group( P < 0. 01). Except the TNF-α level was significantly lower in the high dosage treatment group, there was no other effect in inflammatory cytokines and HYP content in serum. HE pathological section confirmed that the Bletilla striata polysaccharide treatment group can not effectively prevent lung fibrosis.

CONCLUSION

The Bletilla striata polysaccharide has remarkable regulation effect on antioxidation system and immune system, but can not effectively prevent lung fibrosis, more effort should be made to study the active antipulmonary fibrosis components of Bletilla striata.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

Inflammatory factors were significantly associated between IS and whole lung lavage fluid, which could indicate early lung injury in pneumonoconiosis patients.