Relationship between plasma SP-A expression level and disease stage in silicosis patients / 上海预防医学

ObjectiveTo investigate the relationship between plasma surfactant protein⁃A （SP⁃A） expression level and silicosis progression， and to provide early evidence for exploring whether SP⁃A can be used as a biomarker for clinical monitoring of silicosis disease progression. MethodsWe recruited 187 silicosis patients in Guangdong Province hospital for occupational disease prevention and treatment between November， 2019 and November，2020. Their peripheral venous blood samples were collected for the plasma isolation. The level of pulmonary SP⁃A was detected by enzyme-linked immunosorbent assay. ResultsThere was a statistically significant difference in the level of SP⁃A among the silicosis groups （P<0.05）， and the plasma SP-A level of the silicosis patients in stage Ⅲ was higher than that in stage Ⅰ and stage Ⅱ （P<0.05）. Smoking had effect on plasma SP⁃A levels， Age， working years and drinking had no effect on plasma SP⁃A levels. ConclusionThe expression level of SP⁃A in the plasma of silicosis patients is increased， which has a certain correlation with the disease stage， and plays a certain early warning role in the occurrence and development of silicosis， and may be a potential biomarker for the diagnosis and prognosis of silicosis.

Silicosis en el Paraguay: la amenaza no se ha ido

La literatura médica nacional guarda una asignatura pendiente relativa a las enfermedades ocupacionales. La silicosis es la neumoconiosis más frecuente y se debe a la inhalación de sílice cristalina y, acorde a la susceptibilidad individual junto a la intensidad de exposición y a la concentración del mineral en el aire, puede originar determinadas formas clínicas. La silicosis crónica es la forma más frecuente y se asocia a varios tipos de labores como cavar pozos y el trabajo en canteras. En los últimos tiempos se relatan otros oficios que pueden originar formas más aceleradas de la enfermedad en tiempos más abreviados de exposición, recrudeciendo brotes preocupantes en adultos en edad laboral. Realizamos una revisión narrativa de trabajos observacionales hechos en el Paraguay con el objetivo de analizar varios aspectos puntualizando las aristas clínicas y demográficas regionales.

Occupational diseases remain an unresolved issue in the national medical literature. The most common form of pneumoconiosis is silicosis, which is brought on by inhaling crystalline silica and depending on the susceptibility of the person, the extent of their exposure, and the concentration of the mineral in the air, silicosis can result in different clinical forms. The most prevalent type, chronic silicosis, is linked to a variety of jobs, including well digging and quarry work. In recent times, other trades have been reported that can cause more accelerated forms of the disease in shorter exposure times, worsening worrying outbreaks in working-age adults. With the intention of assessing various elements and highlighting certain clinical and regional demographic aspects, we performed a narrative review of observational studies conducted in Paraguay.

Silicoproteinosis en paciente minero en Colombia. Reporte de caso / Silicoproteinosis in a mining patient in Colombia. Case report

La silicosis pulmonar es una enfermedad ocupacional que continúa ocasionando morbilidad en el mundo. Debido a que el sílice es el mineral más abundante en la tierra y en las rocas, son numerosas las fuentes de exposición laboral a la inhalación del polvo de sílice en varios sectores industriales. Por su parte, la silicoproteinosis pulmonar es una forma aguda muy rara de silicosis, que puede desarrollarse con un período de latencia más corto en comparación con la silicosis, luego de la primera exposición al sílice, y se caracteriza por un rápido deterioro de la función pulmonar, sin respuesta efectiva a ningún tratamiento. Por su forma de presentación tan atípica, reportamos el caso de un hombre de 58 años, con antecedente laboral de trabajo en mina de extracción de oro en socavón

Pulmonary silicosis is an occupational disease that continues to cause morbidity in the world. Because silica is the most abundant mineral in soil and rock, sources of occupational exposure to inhalation of silica dust are numerous in various industrial sectors. Alternately, pulmonary silicoproteinosis is a very rare acute form of silicosis, which can develop with a shorter latency period compared to silicosis after the first exposure to silica, and is characterized by a rapid deterioration of lung function, without effective response to any treatment. Due to its atypical form of presentation, we report the case of a 58-year-old man, with a history of working in a gold mine

Occupational lung diseases in South African miners at autopsy: 2020 surveillance report

The Pathology Division at the National Institute for Occupational Health (NIOH) provides autopsy services for deceased workers who worked in controlled mines or works under the provisions of the South African Occupational Diseases in Mines and Works Act, 1973 (Act No. 78 of 1973). This report describes the ages, commodities, employment durations, and occupational cardio-respiratory diseases in miners whose organs were submitted for autopsies in 2019 and 2020. Data were exported from the PATHAUT database into STATA for analysis. Differences in the proportions of disease (expressed per 1 000) were calculated using the Pearson's chi-square test; significance was set at p ≤ 0.05. There were 759 and 557 records of deceased miners and ex-miners in 2019 and 2020, respectively. Pulmonary tuberculosis decreased from 192/1 000 in 2019 to 153/1 000 autopsies in 2020, and silicosis decreased from 246/1 000 to 223/1 000. However, neither decrease was significant. There was a significant increase in the rate of asbestosis from 50/1 000 in 2019 to 79/1 000 in 2020. Pulmonary tuberculosis (TB), emphysema, and silicosis were the most frequent diseases, with high rates. There was a non-significant decrease in occupational respiratory disease rates in 2020 from 2019, but these remain higher than the rates seen in the early 1990s. The NIOH continues to conduct autopsy surveillance on miners to support compensation for families, and the development of policy and intervention programmes in the mining industry

The incidence of artificial stone-related silicosis among interior decoration workers in different countries / 中华劳动卫生职业病杂志

In this paper, 177 cases of artificial stone-related silicosis in interior decoration workers from Israel, Spain, USA, Italy and Australia were analyzed. Interior decoration workers were from small businesses (or workshops), engaged in kitchen and/or bathroom artificial stone countertops cutting, grinding, polishing and other reprocessing. In the working environment, the content of crystalline silica in artificial stone was more than 70%, and the concentration of silica dust exceeded the relevant standards. Most workplaces used dry cutting without ventilation and dust removal and other dust-proof measures, and most workers did not wear qualified respiratory protective equipment. Taking comprehensive measures such as wet operation, ventilation and dust removal, and individual protection can effectively prevent the occurrence of artificial stone-related silicosis.

Epidemiological characteristics of pneumoconiosis deaths in a certain area from 1961 to 2020 / 中华劳动卫生职业病杂志

Objective: To investigate the epidemiological characteristics of pneumoconiosis deaths in Putuo District of Shanghai, and to provide evidence for prevention and management of pneumoconiosis in the future. Methods: In June 2021, the data of 263 patients with pneumoconiosis who died from January 1961 to December 2020 in Putuo District of Shanghai were retrospectively analyzed. Trend χ(2) test, analysis of variance and Spearman rank correlation methods were used to analyze the basic information, age of exposure to dust, promotion period, course of disease and direct cause of death of patients with pneumoconiosis. Results: Among the 263 cases of pneumoconiosis patients who died in Putuo District of Shanghai from 1961 to 2020, 260 cases (98.86%) were male. The main types of pneumoconiosis were foundry worker pneumoconiosis (53.23%, 140/263) and silicosis (43.73%, 115/263). The main types of pneumoconiosis were sand cleaner (36.50%, 96/263). The age of onset was (53.42±10.13) years old, the age of death was (76.14±9.12) years old, and the age of exposure to dust was (20.91±8.99) years. The duration of dust exposure was negatively correlated with the duration of disease (r(s)=-0.24, P<0.001). With the increase of pneumoconiosis stage, the mortality of silicosis and foundry worker pneumoconiosis also showed an increasing trend (χ(2)(trend)=4.22, 3.87, P=0.040, 0.049). 31.94% (84/263) of pneumoconiosis patients died directly from pneumoconiosis, ranking first among the direct causes of death. Conclusion: The death cases of pneumoconiosis in Putuo District of Shanghai are mainly foundry worker pneumoconiosis and silicosis, and pneumoconiosis is the main cause of death.

Evaluation of right ventricular function using two-dimensional speckle tracking echocardiography and analysis of the risk factors for right ventricular dysfunction in patients with silicosis / 中华劳动卫生职业病杂志

Objective: To evaluate the right ventricular function using two-dimensional speckle tracking echocardiography (2-D STE) and analyze the associated risk factors of right ventricular dysfunction in patients with silicosis. Methods: All 104 patients with silicosis treated in the Department of Occupational Medicine and Toxicology in Beijing Chao-Yang Hospital, Capital Medical University from May 2021 to September 2022 were enrolled in this study in October 2022. The clinical information of patients such as general data, arterial blood gas analysis and pulmonary function test were collected. The right ventricular function of patients was evaluated by 2-D STE-derived right ventricular free wall longitudinal strain (RVFWLS) and conventional echocardiographic-derived parameters, including right ventricular fractional area change (RVFAC), tricuspid annular plane systolic excursion (TAPSE) and doppler tissue imaging-derived tricuspid lateral annular systolic velocity (S'), respectively. Based on their RVFWLS, the patients were divided into right ventricular dysfunction group and normal right ventricular function group. Risk factors for right ventricular dysfunction in patients with silicosis were analyzed using binary logistic regression analysis. Results: A total of 104 silicosis patients were enrolled, with aneverage age (65.52±11.18) years old, among whom including 57 cases diagnosed with stage Ⅰ/Ⅱ silicosis and 47 cases diagnosed with stage Ⅲ silicosis. 26 (25.00%) patients concurrent right ventricular dysfunction. The abnormal rates of RVFAC, TAPSE and S' in patients were 16.35% (17 cases), 21.15% (22 cases) and 6.73% (7 cases), respectively. The RVFAC and TAPSE in right ventricular dysfunction group were lower than those in normal right ventricular function group, and the incidence of pulmonary arterial systolic pressure ≥36 mmHg was higher than that in normal right ventricular function group (P<0.05). Logistic regression analysis showed that arterial partial pressure of oxygen (OR=0.932, 95%CI: 0.885-0.981, P=0.007) was the protective factor, and the forced expiratory volume in 1 second (FEV(1)) /forced vital capacity (FVC) ratio<70% (OR=5.484, 95%CI: 1.049-28.662, P=0.044) and stage Ⅲ silicosis (OR=6.343, 95%CI: 1.698-23.697, P=0.007) were the risk factors for silicosis patients concurrent right ventricular dysfunction. Conclusion: The incidence of right ventricular dysfunction is higher in patients with stage Ⅲ silicosis than that in patients with stage Ⅰ/Ⅱ silicosis. Using 2-D STE can help the early detection of silicosis with right ventricular dysfunction. Hypoxemia, airflow limitation and the stage Ⅲ silicosis are the risk factors for silicosis patients concurrent right ventricular dysfunction.

A systematic review of the epidemiology and clinical characteristics of artificial stone-related silicosis and dust protection / 中华劳动卫生职业病杂志

Objective: To investigate the epidemiology, clinical characteristics, on-site dust monitoring and individual protection of the patients with artificial stone-related silicosis. Methods: In March 2022, the literature on artificial stone-related silicosis published from January 1965 to February 2022 was searched in China Journal Full-text Database, Wanfang Database, VIP Database, EMbase and PubMed. Chinese and English search terms include "silica dust""silica dust""silicosis""artificial stone""pneumoconiosis", etc. References were included according to inclusion and exclusion criteria, and data were extracted. The epidemiological characteristics, natural course of disease, workplace dust concentration and individual protection level of patients with artificial stone-related silicosis were analyzed by systematic review. Results: A total of 30 literatures were included, including 7 cohort studies, 14 cross-sectional studies, 3 case-control studies and 6 case reports. A total of 1358 patients with artificial stone-related silicosis were diagnosed from 1997 to 2020, with an average age of 41.5 years old and an average dust exposure time of 11.3 years. Among them, 36.2% (282/778) had progressive mass fibrosis or accelerated progressive silicosis at first diagnosis. Chest imaging showed diffuse small nodule shadow, pulmonary fibrosis, and silico-alveolar proteinosis. Pulmonary function showed restricted or mixed ventilation disorder with or without decreased diffusion volume. The disease progressed rapidly, with progressive mass fibrosis, respiratory failure, and even death. Patients engaged in artificial quartz stone processing, with high concentration of silica including ultra-fine particles, most of which were dry operation, lack of on-site ventilation measures and no effective personal protection. Conclusion: The artificial stone processing workers suffer from artificial stone-related silicosis due to dry cutting, lack of on-site dust removal facilities and personal protective measures, and the disease progresses rapidly, leading to poor prognosis.

Relationship between interleukin-1β and silicosis development / 中国基层医药

Silicosis is a diffuse pulmonary fibrosis disease caused by occupational exposure to silica, which is one of the occupational diseases with high incidence in developing countries. Up to now, there is no definite drug to relieve or reverse the lung injury caused by silicosis, so it is very important to prevent, diagnose and treat pulmonary fibrosis as soon as possible. Studies have shown that a chronic inflammatory environment contributes to pulmonary fibrosis to a certain extent. Interleukin-1β is a cytokine that increases the number of inflammatory factors in the microenvironment in the immune response and plays a key role in inflammatory reaction. Therefore, the release of interleukin-1β is of great significance in the pathogenesis of silicosis. This paper aims to systematically expound the development course of silicosis, the signal pathway of interleukin-1β production, and the relationship between them.

Analysis of epidemiological characteristics of newly diagnosed occupational pneumoconiosis in Henan Province from 2006 to 2020 / 中国职业医学

Objective: To analyze the epidemiological distribution of new occupational pneumoconiosis (hereinafter referred as pneumoconiosis) in Henan Province from 2006 to 2020. Methods: Clinical data of newly recruited pneumoconiosis cases from 2006 to 2020 in Henan Province were retrospectively analyzed. Results: A total of 9 624 cases of newly diagnosed pneumoconiosis were reported in Henan Province in the past 15 years, of which 98.6% were males. The number of cases had two peaks, one in 2009-2011 and the other in 2014-2017. There were 12 types of pneumoconiosis of all reported cases except for mica pneumoconiosis, in which coal workers' pneumoconiosis and silicosis accounted for 96.0%. The incidence of phase Ⅰ, Ⅱ and Ⅲ pneumoconiosis was 64.7%, 21.0% and 14.3%, respectively. The incidence of phase Ⅱ and Ⅲ silicosis was higher than that of coal miners' pneumoconiosis (56.3% vs 22.7%, P<0.01). Patients with pneumoconiosis were mainly distributed in Zhengzhou City, Sanmenxia City, Luoyang City, Pingdingshan City and Hebi City, accounting for 85.0%. The enterprises involved were mainly mining industry, large- and medium-sized enterprises, state-owned enterprises and collective enterprises. The top five position of patients were coal miners, rock drillers, excavators, coal mixed workers and pure coal miners, total accounting for 72.0%. There were 196 enterprises reported ≥10 cases, accounting for 17.2% of all enterprises and 80.3% of the total of newly diagnosed pneumoconiosis cases. The median (M) of onset age of new cases was 49 years old, and the M of onset of working age was 16 years. The onset age of silicosis was younger (M: 49 vs 48 years old, P<0.05), while the onset of working age was longer (M: 10 vs 20 years, P<0.05), compared with that of coal workers' pneumoconiosis. Conclusion: The incidence of pneumoconiosis in Henan Province were disease clustering distribution, regional distribution, industry of enterprise, enterprise scale, enterprise type, nature and working position distribution of enterprises. And it showed the characteristics of group incidence. The prevention and control treatment of pneumoconiosis should be strengthened in key areas, key enterprises and key diseases and jobs.

The role of surfactant associated protein-A in silicosis / 中国职业医学

Objective: To investigate the role of surfactant associated protein-A (SP-A) in the development and progression of silicosis, and its mechanism. Methods: Homozygous and heterozygous mice of SP-A knockout of specific pathogen free (SPF) grade were selected for mating, and mice with SP-A-/- genotype were selected for subsequent experiments. SP-A wild-type (SP-A+/+) and SP-A-/- mice were divided into SP-A+/+ control group, SP-A-/- control group, SP-A+/+ silicosis group and SP-A-/- silicosis group with six mice in each group by random number table method. Mice in both silicosis groups were given 20.0 μL 250 g/L silica suspension by tracheal exposure, and mice in both control groups were injected with 0.9% sodium chloride solution at the same volume. On the 28th day after modeling, mice were sacrificed. Lung tissues were used for lung histopathology examination. The apoptosis of alveolar type Ⅱ epithelial cells of mice was detected by TUNEL method. The mRNA expression of B-lymphoblastoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), cysteinyl aspartate specific proteinase (Caspase)-3 and Caspase-9 in lung tissues of mice was detected by quantitative real-time polymerase chain reaction. Results: The histopathological result of mice showed that thickened alveolar septum, scattered silicon nodule and collagen fiber formation were observed in the mice lungs of SP-A+/+ silicosis group, and a large number of inflammatory cells were observed in silicosis nodule, after exposure to silica dust. SP-A-/- silicosis group resulted in a more severe pulmonary inflammation and interstitial fibrosis compared to SP-A+/+ silicosis group. The apoptosis of alveolar type Ⅱ epithelial cells and the mRNA relative expression levels of Bax, Caspase-3 and Caspase-9 in lung tissues of mice in each silicosis groups were increased compared with their control groups (all P<0.05). The above four indexes of mice in SP-A-/- silicosis group were higher than those in SP-A+/+ silicosis group (all P<0.05). There was no significant difference in the expression of Bcl-2 mRNA in lung tissues of these four groups (P>0.05). Conclusion: Knockout of SP-A can aggravate inflammation and pulmonary fibrosis in silicosis model mice, and promote apoptosis of alveolar type Ⅱ epithelial cells. The mechanism may be related to the Bcl-2/Bax/Caspase-3 signaling pathway which affects the apoptosis of mitochondrial pathway.

Establishment of mouse silicosis fibrosis model by non-exposed tracheal perfusion / 中国职业医学

Objective: To establish a convenient non-invasive tracheal perfusion method for constructing a mouse model of silicosis-induced pulmonary fibrosis. Methods: The specific pathogen-free C57BL/6 mice were randomly divided into control group and model group, with 15 mice in each group. After anesthesia, a 22G arteriovenous indwelling needle was used to inset into the trachea through the mice's mouth. The model group mice were perfused with 0.1 mL of silica suspension with a mass concentration of 25 g/L, and the mice in the control group were perfused with an equal volume of 0.9% sodium chloride solution. On the 7th, 14th, and 30th day after modeling, the body weight of the mice was measured, and the lung tissue morphology and pathological changes were observed. The expression of α-smooth muscle actin (α-SMA) and collagen type 1 alpha 1 (COL1A1) protein in lung tissue of mice was detected by immunofluorescence on the 30th day after modeling. Results: There was no death of mice in the two groups during the experiment. There was no significant difference in body weight between the two groups (P>0.05). The lung tissues of the mice in the model group were pinkish-gray and uneven in color on the 7th and 14th days after dust exposure. On the 30th day after dust exposure, the lung tissue of the mice in the model group was gray and hard, and unevenly distributed silicon nodules were visible by the naked eyes. The histopathology results of lung tissue showed that compared with the mice in control group, the model group mice exhibited persistent aggravation of pulmonary inflammation, thickening of alveolar septum, infiltration of inflammatory cells gradually clustering into clumps, and an increasing number of fibrous foci.On the 30th day after dust exposure, the relative expression of α-SMA and COL1A1 proteins in the lung of the model group was higher than those in the control group (median： 72.59 vs 5.91, 35.62 vs 10.07, both P<0.05). Conclusion: The method of tracheal perfusion silica suspension of mice using 22G arteriovenous indwelling needle can successfully construct an animal model of silicosis fibrosis. This method is convenient, safe and effective, and is worth promoting.

Intervention effect of physical exercise on silicotic mice / 环境与职业医学

Background Pneumoconiosis is the most serious occupational disease in China, and silicosis accounts for about half of it. Any intervention effect of physical exercise as the key and core of lung rehabilitation training on silicosis is still unclear. Objective To explore potential intervention effect of physical exercise on silicotic mice. Methods Forty SPF C57BL/6 male mice were randomly divided into four groups, 10 in each group, including a control group, a physical exercise group, a silicosis model group, and a silicosis model + physical exercise intervention group. Silicotic mouse model was established by using 50 μL SiO2 suspension (200 mg·mL−1). A treadmill was used to prepare mice receiving physical exercise at 0° inclination, 12.3 m·min−1, 60 min·d−1, 5 d·week−1 for 4 weeks. Pathological morphology of lung tissues was evaluated after hematoxylin-eosin (HE) staining; deposition of collagen in lung tissues was evaluated after Van Gieson (VG) staining; expression of p-protein kinase R-like endoplasmic reticulum kinase (PERK) was detected by immunofluorescence staining; expressions of cyclin dependent kinase inhibitors (p21) and p-p38 mitogen activated protein kinase (p38) were detected by immunohistochemistry. The protein expressions of endoplasmic reticulum stress signal factors [p-inositol-requiring enzyme-1α (p-IRE-1α), p-PERK, and p-eukaryotic initiation factor-2α (p-eIF-2α)], senescence signal factors (p-p53, p21, and p16), mitogen-activated protein kinase (MAPK) signal factors [p-p38, p-extracellular regulated protein kinases (p-ERK), and p-stress-activated protein kinase (p-JNK)] were detected by Western blotting. Results After designed acute SiO2 exposure, the images of micro computed tomography (CT) showed high density shadows in lung tissues of the silicotic mice and less shadows in lung tissues of the physical exercise intervention mice. After HE staining, the proportions of silicotic nodule area in lung tissues was (18.67±3.89) % in the silicosis model group, and significantly decreased to (8.78±1.05) % in the silicosis model + physical exercise intervention group (P<0.05). After VG staining, the proportion of collagen fiber area of lung tissues was (10.37±2.18) % in the silicosis model group, and significantly decreased to (4.35±0.89) % in the silicosis model + physical exercise intervention group (P<0.05). The results of immunofluorescence staining showed that in the silicosis model group, the expression of p-PERK increased at the location of silicotic nodules, while in the silicotic model + physical exercise intervention group, the expression of p-PERK decreased. The immunohistochemical staining results showed that the expression of p21 and p-p38 increased in the lung tissues of the silicosis model group; the expression of p21 and p-p38 decreased in the lung tissues of the silicosis model + physical exercise intervention group. The results of Western blotting showed that compared with the control group, the expression levels of p-IRE-1α (0.11±0.03), p-PERK (0.95±0.40), p-eIF-2α (3.53±0.91), p-p53 (1.78±0.07), p21 (1.98±0.10), p16 (1.26±0.17), p-p38 (0.41±0.09), p-ERK (0.42±0.05), and p-JNK (3.20±1.23) of the silicosis model group were all upregulated (P<0.05). Compared with the silicosis model group, the expression levels of p-IRE-1α (0.03±0.01), p-PERK (0.31±0.12), p-eIF-2α (0.30±0.06), p-p53 (0.76±0.08), p21 (0.18±0.11), p16 (0.70±0.24), p-p38 (0.03±0.00), p-ERK (0.19±0.03), and p-JNK (0.46±0.21) of the silicosis model + physical exercise intervention group were downregulated (P<0.05). Conclusion Physical exercise may alleviate pulmonary fibrosis in silicotic mice, and inhibit abnormal expressions of endoplasmic reticulum stress signal, MAPK signal, and senescent signal.

Epidemiological characteristics of newly diagnosed occupational pneumoconiosis in Guangdong Province from 2011 to 2020 / 中国职业医学

Objective To analyze the epidemiological characteristics of newly diagnosed occupational pneumoconiosis (hereinafter referred to as "pneumoconiosis") in Guangdong Province from 2011 to 2020. Methods Clinical data of newly diagnosed pneumoconiosis in Guangdong Province from 2011 to 2020 was collected from the “Health Hazards Monitoring Information System” under “China Disease Prevention and Control Information System”. The distribution of the cases was analyzed retrospectively. Results A total of 2 731 cases of newly diagnosed pneumoconiosis were reported from 2011 to 2020 in Guangdong Province, with cases at stages Ⅰ,Ⅱ, and Ⅲ accounting for 61.6%, 23.8%, and 14.6%, respectively. Except for talc pneumoconiosis, 12 other types of pneumoconiosis were reported. The top three incidence of diseases were silicosis, other pneumoconiosis, and welder's pneumoconiosis, accounting for 58.8%, 22.0% and 11.0%, respectively. Males accounted for 97.5%, and females 2.5%. The median age of onset was 47 years old. The median dust exposure duration was 9.8 years, with 19.4% of cases having a dust exposure duration less than 5.0 years. And 80.7% of the cases were distributed in the Pearl River Delta region. The industries with the new cases were mainly the manufacturing (accounting for 69.4%), and 34.8% of cases were found in private limited liability companies. Cases in medium- and small-sized enterprises accounted for 35.7% and 34.3% respectively. Conclusion Silicosis, other pneumoconiosis, and welder's pneumoconiosis are predominant in Guangdong Province. The prevention and control of pneumoconiosis should focus on small- and medium-sized private enterprises in the concentrated manufacturing industry in the Pearl River Delta region.

Clinical characteristics of artificial quartz stone silicosis patients / 中国职业医学

Objectives To explore and compare the clinical characteristics and risk factors for mortality between patients with artificial quartz stone silicosis and those with classic silicosis. Methods A total of 48 patients with artificial quartz stone silicosis (experiment group) and 98 patients with classic silicosis (control group) were recruited as the research subjects using the convenience sampling method. Data of clinical symptoms, laboratory tests, high-resolution computed tomography (HRCT), and pulmonary pathology of the research subjects were retrospectively analyzed. The Cox proportional hazards regression model was used to analyze the influencing factors on the survival time of silicosis patients. Results Patients in the experiment group had shorter years of dust exposure, latency period and time since last exposure than those in the control group (all P<0.01). The positive rate of anti-nuclear antibodies and the expression of neuron-specific enolase in the experiment group were higher than those in the control group (39.6% vs 10.2%, median： 28.44 vs 16.25, both P<0.01). The PaO2 levels in the experiment group were lower than those in the control group (median： 66.0 vs 89.0, P<0.01). The patients in the experiment group had lower vital capacity, inspiratory reserve volume, forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), and carbon monoxide diffusion capacity compared to the control group (all P<0.05), but the maximal expiratory flow in 75% vital capacity was higher than the control group (P<0.05). Compared with the control group, patients in the experiment group had the presence of ground-glass opacity (GGO) in both lungs, aggregation and fusion of subpleural nodules, and gradual formation of progressive massive fibrosis (PMF), with higher potential of pneumothorax. Within 5 years after diagnosis, the mortality of patients in the experiment group was higher than that in the control group (27.1% vs 4.1%, P<0.01). The Cox regression model analysis results showed that patients with nodule aggregation on lung HRCT images had a higher risk of mortality than those without nodule aggregation, and lower lung function including vital capacity, FVC, FEV1 and maximum expiratory flow in 25% vital capacity had higher risk of reduced survival time (all P<0.05). Conclusion Compared with patients with classic silicosis, patients with artificial quartz stone silicosis have higher level of serum neuron-specific enolase, increasing the risk of autoimmune diseases. Pulmonary imaging features in patients with artificial quartz stone silicosis include GGO, PMF and susceptibility to pneumothorax, and rare calcification of mediastinal lymph nodes, leading to a higher mortality rate within 5 years after diagnosis.

Exploring the mechanism of action of curcumin in the treatment of silicosis based on network pharmacology and molecular docking / 中国职业医学

Objective To explore the mechanism of action of curcumin in the treatment of silicosis by network pharmacology combined with molecular docking technology. Methods The targets prediction network of curcumin in treating silicosis was established based on the collection of targets of curcumin and silicosis in multiple databases, cross-targets were submitted to the STRING database, and their connectivity was analyzed by Cytoscape software. Gene ontology (GO) function analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed on the top 20 genes. The molecular docking was performed on the key targets to study the mechanism of action of curcumin in treating silicosis. Results A total of 311 targets related to curcumin, 270 targets related to silicosis, and 74 cross-targets were obtained from the databases. GO function analysis revealed 2 665 related pathways, and KEGG pathway enrichment analysis revealed 188 related pathways. Molecular docking results showed that curcumin had good binding ability with the targets of mitogen-activated protein kinase 3 (MAPK3), interleukin (IL) 6, serine/threonine kinase 1 (AKT1), vascular endothelial growth factor A (VEGFA), signal transducer and activator of transcription 3, albumin, Jun proto-oncogene, tumor necrosis factor (TNF), IL1B, tumor protein p53, C-C motif chemokine ligand 2 and fibronectin 1. Conclusion The therapeutical effects of curcumin on silicosis were implemented through multi-targets and multi-pathways. Curcumin may play a role in the treatment of silicosis by binding to the core targets MAPK3, IL6, AKT1, VEGFA and TNF and regulating the MAPK, IL6, TNF, phosphatidylinositol 3-kinase/protein kinase B and VEGF signaling pathways.

Analyzing the current status of newly diagnosed occupational pneumoconiosis patients in Zhangdian District of Zibo City / 中国职业医学

Objective To analyze the distribution, survival conditions, and medical support of newly diagnosed occupational pneumoconiosis (hereinafter referred to as pneumoconiosis) patients in Zhangdian District, Zibo City. Methods A total of 1 189 newly diagnosed pneumoconiosis patients in Zhangdian District from 1956 to 2019 were selected as the study subjects using retrospective method. Data of their age of onset, years of occupational exposure, category of working industry, type of pneumoconiosis, and status of medical support was collected and analyzed. Results The median and the 25th-75th percentiles ［M (P25, P75)］ of the age of onset were 51.8 (45.5, 56.1) years, and the mortality was 37.0%. The majority of pneumoconiosis cases were silicosis (45.2%) and coal workers' pneumoconiosis (39.8%). The highest prevalence of pneumoconiosis was in the coal mining and washing industry (42.4%), followed by manufacturing (33.4%). Pneumoconiosis patients in stage Ⅰ,Ⅱ, and Ⅲ accounted for 89.1%, 8.7%, and 2.2%, respectively. The M (P25, P75) of the length of work exposed to dust were 24.1 (16.5, 29.9) years.The higher stage of pneumoconiosis the shorter of the length of work exposed to dust among these pneumoconiosis patients(all P<0.05). The overall survival rate, the 5-year survival rate and the 10-year survival rate of these pneumoconiosis patients were 63.0%, 92.3% and 85.9%, respectively. Among the 749 surviving cases, 60.8% were aged 60.0 to <80.0 years. In terms of social security, 100.0% surviving cases enjoyed basic medical insurance, meanwhile, 96.1% and 81.8% patients were covered by major medical insurances and occupational injury insurances, respectively. The M (P25, P75) of age at death were 73.1 (64.0, 77.1) years. The main causes of death were respiratory diseases (59.3%) and malignant tumors (20.4%). Conclusion The prevalent types of pneumoconiosis in Zhangdian District, Zibo City, are coal workers' pneumoconiosis and silicosis. Medical support and assistance are relatively limited. The pneumoconiosis prevention and control focus should be on silicosis and coal workers' pneumoconiosis, particularly in the manufacturing industry.

A case report of stage Ⅲ silicosis complicated by pulmonary tuberculosis and secondary pneumothorax treated with minimally invasive thoracoscopic surgery / 中国职业医学

Objective To analyze the feasibility of using minimally invasive thoracoscopic surgery to treat stage Ⅲ silicosis complicated by pulmonary tuberculosis and secondary pneumothorax. Methods This study retrospectively analyzed the clinical data of a patient with stage Ⅲ silicosis complicated by pulmonary tuberculosis and secondary pneumothorax. Results The patient had stage Ⅲ silicosis complicated with active pulmonary tuberculosis for 1.5 years. In March 2021, a left-sided pneumothorax occurred and was conservatively treated with closed chest drainage. In April 2022, the patient was admitted with sudden frequent coughing and left-sided chest discomfort. Based on occupational history, dust exposure history, high-kilovolt anterior-posterior chest radiography, chest computed tomography, and sputum smear results, the diagnosis was "stage Ⅲ silicosis; active tuberculosis (positive for acid-fast bacilli in sputum smear); left-sided pleural effusion, pulmonary bulla rupture; secondary pneumothorax (recurrent tension type in left, encapsulated in right); left pleural adhesion". On the second day of admission, left-sided closed chest drainage was performed with poor outcome. On the fifth day of admission, minimally invasive thoracoscopic treatment was performed, including left lung volume reduction, pleural adhesion cauterization, and pleural fixation. Postoperative anti-inflammation, anti-tuberculosis, and symptomatic supportive treatments were administered. Due to the patient's severe underlying disease, wound healing was slow postoperatively, but no serious complications occurred. The pneumothorax completely absorbed and recovered in 17.0 days. Conclusion Minimally invasive thoracoscopic surgery is an effective treatment for silicosis complicated with pulmonary tuberculosis and secondary pneumothorax, and it is worth promoting.

Regulation of PGC1α on SiO2-induced lipid accumulation in macrophages and fibrosis in pulmonary fibroblasts / 环境与职业医学

Background The pathogenesis of silicosis is complex and treatment methods are limited. SiO2-induced increase of transforming growth factor-β1 (TGF-β1) can activate fibroblasts to promote collagen deposition, ultimately leading to fibrosis. Previous studies have confirmed that lipid metabolism plays an important role in the progression of silicosis. Peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) mediates mitochondrial dysfunction and lipid metabolism pathways in diabetic models, but its role in silicosis has not been elucidated. Objective To investigate the effect of PGC1α on lipid metabolism disorder of macrophages induced by SiO2 and its effect on the progression of silicosis fibrosis. Methods (1) Macrophages were divided into four groups by transfecting and silencing PGC1α and its control sequence in macrophages and followed by SiO2 stimulation: negative control group (transfected with si-NC for 48 h), si-PGC1α group (transfected with si-PGC1α for 48 h), SiO2 stimulation group (stimulated with 50 μg·mL−1 SiO2 for 36 h after transfection with si-NC for 48 h), and si-PGC1α+SiO2 group (stimulated with 50 μg·mL−1 SiO2 for 36 h after transfection with si-PGC1α for 48 h). Western blot and cell immunofluorescence were used to test PGC1α expression, 4,4-difluoro-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene (BODIPY 493/503) and total cholesterol (TC) and free cholesterol (FC) kits were used to test lipid accumulation, and the Oroboros2k-Oxygraph respiratory test system (O2K) was used to assess the effects of PGC1α on mitochondrial respiratory chain. ELISA kits were used to test TGF-β1 expressed in the macrophage supernatant. (2) Lung fibroblasts were divided into the same four groups as above, and stimulated with the supernatant of macrophages in the above groups. The expression of collagen Ι (COL Ι), E-cadherin (Eca), and fibronectin (FN) were detected by cell immunofluorescence and Western blot to further evaluate the effect of silencing PGC1α on fibrosis. Results The protein expression level of PGC1α stimulated by SiO2 was decreased, and the relative expression level of PGC1α was 0.78 times that of the control group (P<0.05). After transfection with si-PGC1α, the expression of PGC1α was decreased, and the relative protein expression level of the si-PGC1α group was 0.86 times that of the control group (P<0.05). Compared with the SiO2 stimulation group, the staining area of BODIPY 493/503 in the si-PGC1α+SiO2 group was enhanced, and the cholesterol-related indexes [TC, FC and cholesterol ester (CE)] were increased to 1.38, 1.10, and 2.26 times those in the SiO2 stimulation group (P<0.05). The activity of mitochondrial complex Ι was decreased, and the level of complex Ι in the si-PGC1α+SiO2 group was 0.63 times that in the SiO2 stimulation group (P<0.05). The secretion of TGF-β1 by macrophages increased, and the level of TGF-β1 in the si-PGC1α+SiO2 group was 1.15 times that of the SiO2 stimulation group (P<0.05). In addition, after stimulation of primary lung fibroblasts with macrophage supernatant, silencing PGC1α increased the expression levels of COL Ι and FN, while decreased the expression of Eca. The protein levels of COL Ι, FN, and Eca in the si-PGC1α+SiO2 group were 1.39, 1.18, and 0.82 times those in the SiO2 stimulation group, respectively (P<0.05). Conclusion Silencing PGC1α exacerbates SiO2-induced lipid metabolism disorder, inhibits mitochondrial respiratory chain, and aggravates the fibrosis induced by SiO2, suggesting that PGC1α may participate silicosis fibrosis by regulating mitochondrial respiratory chain and lipid metabolic disorder induced by SiO2.

Mechanism of osteoclast stimulatory transmembrane protein promoting silicosis fibrosis by inducing ferroptosis / 环境与职业医学

Background Osteoclast stimulatory transmembrane protein (OC-STAMP) is involved in silicosis fibrosis induced by silicon oxide (SiO2) exposure. Its role in silicosis fibrosis by inducing ferroptosis of alveolar type II epithelial cells and its related mechanism remain unclear. Objective To explore the effect and possible mechanism of OC-STAMP on ferroptosis of alveolar type II epithelial cells and silicosis fibrosis in rats under SiO2 exposure. Methods Twenty male Wistar rats of SPF grade were randomly divided into two groups: control (Sham) group and SiO2 group, 15 rats in each group. Rats in the SiO2 group were given 1 mL of 50 mg·L−1 SiO2 suspension at one time through the non-exposed intratracheal instillation method to establish an animal model of silicosis, and rats in the Sham group were give 1 mL of 0.9% sodium chloride solution in the same way. Rats were sacrificed after 8 weeks. Samples of lung tissue were fixed in glutaraldehyde or paraformaldehyde for observing ultrastructure of mitochondria by transmission electron microscopy; HE, Masson, VG, and Prussian blue were used to observe changes in lung tissue structure and iron deposition. The expression level of OC-STAMP and the degree of lung fibrosis were evaluated by immunohistochemistry and immunofluorescence. The expression level of OC-STAMP in rat lung tissue was detected and the transfection effect of OC-STAMP was verified by real-time fluorescence quantitative polymerase chain reaction (RT-PCR). Overexpression (OCS group) and inhibition expression (SI-OC group) models were constructed by OC-STAMP plasmid and OC-STAMP small interfering RNA (siRNA) transfection to cultured MLE-12 cells, respectively. The relative expression levels of glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11), and other proteins in lung tissue and MLE-12 were detected by Western blotting. Results The results of HE, Masson, and VG staining showed that the silicosis modeling was successful after 8 weeks of SiO2 exposure. The immunofluorescence results showed that OC-STAMP and ATP binding cassette subfamily A member 3 (ABCA3) co-localized in alveolar type II epithelium. The immunohistochemical results showed that the levels of OC-STAMP and collagen I in the SiO2 group were significantly higher than those in the Sham group (P<0.01). The RT-PCR results showed that the OC-STAMP mRNA in the lung tissue of the SiO2 group was significantly higher than that of the Sham group (P<0.01). The Prussian blue staining in the lung tissue of the SiO2 group showed positive brownish-yellow particles. Compared with the Sham group which showed normal mitochondrial structure, the mitochondrial structure was generally swollen and the mitochondrial cristae dissolved and disappeared in the SiO2 group by transmission electron microscope observation. The Western blotting results showed that the expression levels of SLC7A11 and GPX4 both decreased in the lung tissue of the SiO2 group (P<0.05, P<0.01), and the expression level of Vimentin increased (P<0.01). In the transfected MLE-12 cells, compared with the Sham group, the expression levels of SLC7A11 and GPX4 in the OCS group were significantly reduced (P<0.05, P<0.01). Conclusion OC-STAMP may affect the expression of proteins related to ferroptosis, and promote lung fibrosis induced by SiO2 exposure.