Respirable coal mine dust in underground mines, United States, 1982-2017.

BACKGROUND: This study summarized the mass concentration and quartz mass percent of respirable coal mine dust samples (annually, by district, and by occupation) from underground coal mines during 1982-2017. METHODS: Respirable dust and quartz data collected and analyzed by Mine Safety and Health Administration (MSHA) were summarized by year, coal mining occupation, and geographical area. The older (before August 2016) 2.0 mg/m 3 respirable dust MSHA permissible exposure limit (PEL) was used across all years for comparative purposes. For respirable dust and quartz, geometric mean and percent of samples exceeding the respirable dust PEL (2.0 mg/m 3 or a reduced standard for samples with >5% quartz content) were calculated. For quartz samples, the average percent quartz content was also calculated. RESULTS: The overall geometric mean concentration for 681 497 respirable dust samples was 0.55 mg/m 3 and 5.5% of the samples exceeded the 2.0 mg/m 3 PEL. The overall respirable quartz geometric mean concentration for 210 944 samples was 0.038 mg/m 3 and 18.7% of these samples exceeded the applicable standard. There was a decline over time in the percent of respirable dust samples exceeding 2.0 mg/m 3 . The respirable dust geometric mean concentration was lower in central Appalachia compared to the rest of the United States. However, the respirable quartz geometric mean concentration and the mean percent quartz content were higher in central Appalachia. CONCLUSION: This study summarizes respirable dust and quartz concentrations from coal mine inspector samples and may provide an insight into differences in the prevalence of pneumoconiosis by region and occupation.

[Clinical characteristics of pneumoconiosis complicated with chronic obstructive pulmonary disease].

Objective: To analyze the pulmonary function and clinical features of coal worker's pneumoconiosis complicated with chronic obstructive pulmonary disease (COPD) , coal worker's pneumoconiosis and COPD, in order to improve the diagnosis and treatment of coal worker's pneumoconiosis complicated with chronic obstructive pulmonary disease. Methods: Selected patients in respiratory department of General Hospital of Jincheng Coal Industry Group were classified as pneumoconiosis complicated with COPD group (n=52) , pneumoconiosis group (n=70) and COPD group (n=50) . Clinical data were collected and compared between three groups, including age, history of smoking, BMI, pulmonary function, CAT score and complication with Hypoxemia and respiratory faliure. Results: The mean age, smoking index and BMI of the three groups were not significantly different. The FEV1% pred, FEV(1)/FVC%, DLco-SB%, FVC% pred were significantly lower in pneumoconiosis complicated with COPD group than pneumoconiosis group (P<0.05) ; The FEV(1)% pred, DLco-SB%, FVC% pred were significantly lower in pneumoconiosis complicated with COPD group than COPD group (P<0.05) , but, the FEV(1)/FVC% was no significant different between pneumoconiosis complicated COPD group and COPD group (P>0.05) ; The CAT score for clinical symptoms of pneumoconiosis complicated with COPD group was significantly higher than that of pneumoconiosis group (P<0.05) , but there was no significant difference between pneumoconiosis complicated COPD group and COPD group (P>0.05) . The rate of hypoxemia in coal workers' pneumoconiosis combined with chronic obstructive pulmonary disease was 78.8%, which was higher than that of coal workers' pneumoconiosis group (61.4%) and chronic obstructive pulmonary disease group (72%) ; The respiratory failure rate of coal worker's pneumoconiosis combined with chronic obstructive pulmonary disease group was 44.2%, which was higher than that of coal worker's pneumoconiosis group (4.3%) and chronic obstructive pulmonary disease group (16%) . Conclusion: In pneumoconiosis patients, once complicate with COPD, the pulmonary function indexes are worse, the clinical symptoms are heavier, and the probability of hypoxemia and respiratory failure are higher. Compared with the COPD group, the patients with pneumoconiosis complicated with COPD have more restrictive ventilation dysfunction and diffuse dysfunction, and the clinical symptoms are heavier, and the probability of combined respiratory failure is higher.

[Correlation research between imaging performance and pulmonary function of pneumoconiosis patients at stage three].

Objective: To study the imaging performance and pulmonary function of pneumoconiosis patients at stage three. Methods: 89 cases of pneumoconiosis patients at stage three for high thousand volt back chest, chest CT, pulmonary function, analysis the relationship of high thousand volt back chest, chest CT manifestations and pulmonary function. Results: In patients with chest X-ray progressive massive fibrosis range of 2.31-102.95 cm(2), divide patients according to the X-ray performance into three groups, the difference of each group pulmonary function index FVC、FEV(1)、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV is statistically significant (P<0.01) , the difference of FEV(1)/FVC%、RV/TLC、DLCO is no statistical significance (P>0.05) . Checked by related, in pneumoconiosis patients at stage three, the X-ray manifestations and pulmonary function index FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV、DLCO showed a negative correlation (r=-0.326, -0.438, -0.251, -0.344, -0.317, -0.337, -0.425, -0.347, -0.230) . With the deterioration of the X-ray imaging findings, pulmonary function index FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV、DLCO is a trend of decrease (P<0.05) . The X-ray changes is not associated with RV/TLC. By linear regression analysis, FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV、DLCO regression equation are meaningful. The RV/TLC regression equations is meaningless. The volume of the patients with chest CT progressive massive fibrosis range of 4.86~179.74 cm(3), divide patients according to the chest CT performance into three groups, the difference of each group pulmonary function index FVC、FEV(1)、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV、RV/TLC is statistically (P<0.05) , the difference of FEV(1)/FVC%、DLCO is no statistical significance (P>0.05) . Checked by related, in pneumoconiosis patients at stage three, chest CT manifestations and pulmonary function index FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV showed a negative correlation (r=-0.360, -0.419, -0.256, -0.432, -0.366, -0.326, -0.254, -0.405, ) , It is not associated with the RV/TLC、DLCO. With the deterioration of the chest CT imaging findings, pulmonary function index FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV is a trend of decrease (P<0.05) . By linear regression analysis, FVC、FEV(1)、FEV(1)/FVC%、PEF、MEF(75%)、MEF(50%)、MEF(25%)、MVV regression equations are meaningful. The RV/TLC、DLCO regression equations are meaningless. Conclusion: It is correlated with chest X-ray, chest CT manifestations and pulmonary function in pneumoconiosis patients at stage three, that could help guide clinicians comprehensive evaluation in patients with pulmonary function status.

[The application of holistic nursing in the rehabilitation of occupational pneumoconiosis complicated with chronic obstructive pulmonary disease].

Objective: To investigate the effect of holistic nursing on the rehabilitation of patients with occupational pneumoconiosis complicated with acute exacerbation of chronic obstructive pulmonary disease (COPD) . Methods: In October 2018, from September 2016 to September 2018, 120 pneumoconiosis patients with copd admitted to the occupational disease department of Laigang Hospital attached to Affilated to Shandong First Medical University were selected, according to random number table method is divided into experimental group (60 cases) and control group (60 cases) in the control group given conventional nursing, the experimental group to implement the holistic nursing, before and after the intervention were compared of two groups of patients with disease recognition grade self-management behavior of related parameters of blood gas analysis and lung function changes. Results: Comparison of disease recognition score between the two groups, the experimental group was higher than the control group (P<0.05) . Comparison of scores of self-management behaviors such as diseases medical management, daily life management. Emotion management and so on between the two groups showed that the experimental group was higher than the control group (P<0.05) . Comparison of blood gas analysis indicators between the two groups showed that PaO(2) in the experimental group was higher than that in the control group (P<0.05) . Comparison of pulmonary function indicators between the two groups showed that FEV(1) and FEV(1)/FVC in the experimental group were higher than that in the control group (P<0.05) . Conclusion: Holistic nursing can effectively improve the cognition of pneumoconiosis patients with copd in the acute exacerbation stage, regulate their self-management behavior, improve arterial oxygen content, improve pulmonary ventilation function. and promote the recovery of the disease.

[Preliminary study on the evaluation of pneumoconiosis].

Objective: Select the appropriate disease assessment indicators, formulate the comprehensive evaluation group of pneumoconiosis patients, and explore the role of the comprehensive evaluation grouping in the clinical evaluation of pneumoconiosis, and provide the basis for the prognosis of pneumoconiosis. Methods: Combined with clinical symptoms, pulmonary function, pneumoconiosis stage, acute exacerbation and complications, a comprehensive assessment of pneumoconiosis patients was established.138 newly diagnosed pneumoconiosis patients were divided into low risk group, middle risk group and (very) high risk group. The patients were followed up by telephone to record their health status and quality of life within one year after discharge from hospital. Analysis of the relationship between the comprehensive assessment group of patients with pneumoconiosis and symptom score, pulmonary function, pneumoconiosis stage, acute exacerbation and complications. The relationship between the comprehensive assessment group of pneumoconiosis patients and the risk events (the number of visits, hospitalization, mechanical ventilation, death cases in one year) and CAT score were analyzed. Results: There were significant differences in clinical symptoms, pulmonary function injury, pneumoconiosis stage, acute exacerbation and complications among patients in low risk group, middle risk group and (very) high risk group (P<0.01) . With the increase of comprehensive assessment score, CAT score increased, the risk events increased, the difference was statistically significant (P<0.01) . Spearman correlation analysis showed that the comprehensive assessment group was significantly correlated with the number of visits, hospitalization, mechanical ventilation, deaths and CAT score in one year. Conclusion: Combined with clinical symptom assessment, pulmonary function assessment, chest imaging assessment, acute exacerbation assessment, and complication assessment, the pneumoconiosis patients' comprehensive assessment group formulated can evaluate the severity of pneumoconiosis patients, and make a more accurate and comprehensive judgement of the disease.

[Clinical abservations of pulmonary surfactant' s autologous transfusion in massive lung lavage].

Objective: Investigate the pulmonary surfactant autotransfusion effect on the recovery of respiratory function in patients with whole lung lavage, to provide theoretical basis for the clinical application. Methods: We taken 30 patients of pneumoconiosis treated by whole lung lavage as the subjects. We extracted the pulmonary surfactant from lavage fluid, after single postoperative lung lavage for the first time; after one weeks when the second times of lung lavage were performed to the other side of the lung of patients, we put PS into the right side. We taken the patients the second times of lung lavage who were put PS into the right side as returning group, the first times of lung lavage who were not put PS into as on returning group. We observed indi-cators, such as expiratory resistance, respiratory work, lung compliance, airway pressure, PO(2), the pulmonary function recovery time and other indicators, comparing with the changes of pulmonary function before lung la-vage for the first time and at 0、60、90、120 min after the pulmonary surfactant autotransfusion. Results: Com-pared with the no returning group, the expiratory resistance of the returning group decreased significantly at 90 min、120 min after the pulmonary surfactant autotransfusion; the respiratory work and airway pressure of the re-turning group decreased significantly at 60、90、120 min after the pulmonary surfactant autotransfusion, there was statistically significant in the difference between different groups (P<0.05, P<0.01). Compared with the no returning group, the lung compliance and the PO(2) of the returning group increased significantly at 60 min、90 min、120 min after the pulmonary surfactant autotransfusion, there was statistically significant in the difference between different groups (P<0.05, P<0.01). The lung function recovery time of returning group was (155.7 ± 35.2) min, the lung function recovery time of no returning group was (183.71±41.81) min, there was statistical-ly significant in the difference between different groups (P<0.05). Compared with the no returning, there were not statistically significant in the difference of the Heart rate、the systolic blood pressure and the diastolic blood pressure about the returning at 60、90、120 min after the pulmonary surfactant autotransfusion.There was no ad-verse reactions such as pulmonary infection, pulmonary infection and so on. Conclusion: The pulmonary surfac-tant autotransfusion may reduce expiratory resistance, work of breathing, airway pressure; improve lung compliance, alveolar ventilation function; increase oxygen partial pressure and decrease the surgery recovery time in patients with pneumoconiosis.

CT patterns of pleuro-pulmonary damage caused by inhalation of pumice as a model of pneumoconiosis from non-fibrous amorphous silicates.

PURPOSE: The aim of this article is to correlate the radiological features of pleuro-pulmonary damage caused by inhalation of pumice (an extrusive volcanic rock classified as a non-fibrous, amorphous, complex silicate) with exposure conditions. MATERIALS AND METHODS: 36 subjects employed in the pumice quarries were evaluated for annual follow-up in a preventive medical surveillance program including spirometry, chest CT lasting from 1999 to 2014. They were only male subjects, mean age 56.92 ± 16.45 years. Subjects had worked in the quarries for an average of 25.03 ± 9.39 years. Domestic or occupational exposure to asbestos or other mineral dusts other than pumice was excluded. Subjects were also classified as smokers, former smokers and nonsmokers. RESULTS: Among the 36 workers examined, we identified four CT patterns which resulted to be dependent on exposure duration and intensity, FVC, FEV1 and FEF25-75, but not on cigarette smoking. The most common symptoms reported by clinical examination were dyspnoea, cough and asthenia. In no case it was proven an evolution of CT findings during follow-up for 10 years. CONCLUSIONS: Liparitosis, caused by pumice inhalation, can be considered a representative example of pneumoconiosis derived by amorphous silica compounds, which are extremely widespread for industrial manufacturing as well as for applicative uses, such as nano-materials. Moreover, being pumice free of quartz contamination, it can represent a disease model for exposure to pure non-fibrous silicates.

Forecasting role of genetic markers in outlining features of pneumoconiosis course in post-contact period.

Based on studies of certain gene-candidate polymorphism, the authors studied markers of early development and unfavorable course of pneumoconiosis in post-contact period. Analysis covered occurrence of genotypes and allels of I/D polymorphism of gene CCRS, 4a/b polymorphism of gene NOS3, VNTR polymorphism of gene ILRN, I/D polymorphism of CASP8 and mutation GLU342LYS (rs28929474) and GLU264VAL (rsl7S80) in gene SERPINAl in patients with various terms of pneumoconiosis formation. Findings are individual criteria of early formation and progress of pneumoconiosis in post-contact period..

[Right ventricular systolic function of patients with pneumoconiosis based on the evaluation of systolic displacement of tricuspid annulus].

OBJECTIVE: To determine the tricuspid annular plane systolic excursion (TAPSE) using M-mode echocardiography, and to evaluate the right ventricular systolic function in patients with pneumoconiosis. METHODS: One hundred and eighty-three patients with pneumoconiosis were enrolled as subjects, and one hundred and ninety-nine healthy volunteers were used as controls. According to the types of ventilation dysfunction, patients were divided into four groups: normal type, obstructive type, restrictive type, and mixed type. In the apex four-chamber sections, the displacement of tricuspid annular plane on the right ventricular free wall side was measured from end-diastole to end-systole using M-mode echocardiography. RESULTS: The average TAPSE in the pneumoconiosis group was significantly lower than that in the control group (18.61 ± 3.08 vs 22.38 ± 3.03 mm, P < 0.01). Along with the progression of pneumoconiosis, the TAPSE values in patients with stage I, II, and III pneumoconiosis were significantly decreased compared with those in the control group (P < 0.01). The TAPSE values in patients diagnosed with normal, obstructive, restrictive, and mixed types of pneumoconiosis in pulmonary function tests were all significantly lower than those in the control group (P < 0.01). Among all patients, patients with mixed type of pneumoconiosis had the most significant reduction in the TAPSE. CONCLUSION: The TAPSE is substantially decreased in patients with pneumoconiosis and further decreased along with the progression of pneumoconiosis. Measurement of the TAPSE is an easy way to evaluate the right ventricular systolic function in patients with pneumoconiosis.

[Comparison of welder's pneumoconiosis with silicosis and follow-up study of welder's pneumoconiosis].

OBJECTIVE: To study the character of welder's pneumoconiosis on CT, pathology, and lung function. METHODS: To contrast 185 welder's pneumoconiosis and 115 silicosis on CT, pathology, and clinical characters which were diagnosed between Jan 2008 and Dec 2013. Chest X-ray and lung function of 39 welder's pneumoconiosis patients were followed up after diagnosed 4~6 years later. RESULTS: Average age and working years of welder's pneumoconiosis were 36.7 and 11.5, less than silicosis patients 58.8 and 22.1, respectively (P<0.05). Of all 185 welder's pneumoconiosis 98.4% were of stage I and no stage III, while in silicosis group stage I, stage II and stage III were 56.5%, 22.6% and 20.9%, respectively. The ratio differences between the two groups were statistically significant,P<0.05. 82.7% of welder's pneumoconiosis patients were observed pathologically moderate or above dust deposition in lung tissue while interstitial fibrosis level was just mild (97.6% patients) or no fibrosis (2.4% patients). By contrast, 60.0% silicosis patients pathologically showed moderate or above dust deposition while 77.8% were of moderate or above fibrosis. CT findings in welder' s pneumoconiosis were diffuse branching linear structure (38.9%), low density consistent size centrilobular micronodules (19.5%), or both (30.8%). Poorly-defined ground-glass attenuation centrilobular micronodules or widely ground glass shadow were observed in 6.4% welder's pneumoconiosis patents. 30.8% patients failed to reach the original stage when 39 welder's pneumoconiosis followed up chest radiograph. CONCLUSION: Changes in welder's lung caused by welding fume were not only siderosis, but also interstitial fibrosis.

[The effect of pneumoconiosis observation object and coal workers' pneumoconiosis in one stage again in the dust exposure work after whole lung lavage].

OBJECTIVE: To investigate the effects of secondary dust exposure after whole-lung lavage (WLL) on the clinical symptoms, arterial blood gas parameters, and pulmonary function in subjects with pneumoconiosis and patients with stage I coal workers' pneumoconiosis (CWP). METHODS: The subjects with pneumoconiosis and patients with stage I CWP who underwent WLL in our hospital during the study period were selected. All patients were divided into postoperative dust exposure group (n = 86) and lavage control group (n = 86) according to whether they were exposed to dust after conventional operation. In addition, their workmates with similar age, history of dust exposure, and type of dust exposure were selected as non-lavage control group (n = 86). Follow-up was performed before and at one month and one year after WLL to evaluate clinical symptoms, arterial blood gas parameters, and pulmonary function. RESULTS: One month after operation, the clinical scores of the postoperative dust-exposure group and lavage control group were significantly reduced compared with their preoperative scores and the clinical score of the non-lavage control group (P < 0.01). One year after operation, the clinical scores of the postoperative dust-exposure group and lavage control group were significantly reduced compared with their preoperative scores and the clinical score of the non?lavage control group (P < 0.01), and the lavage control group had a significantly lower clinical score than the postoperative dust exposure group (P < 0.01). One month after operation, the arterial partial pressure of oxygen (PaO2) of the postoperative dust-exposure group and lavage control group were significantly higher than their preoperative values and the arterial PaO2 of the non-lavage control group (P < 0.01). One year after operation, the lavage control group had significantly higher arterial PaO2 than the postoperative dust exposure group and the arterial PaO2 of the non-lavage control group was significantly lower than its preoperative value and the arterial PaO2 of the postoperative dust exposure group and lavage control group (P < 0.05 or P < 0.01); the postoperative dust exposure group showed a significant decrease in arterial PaO2 (P < 0.01), while the lavage control group showed a significant increase in arterial PaO2 (P < 0.01). The partial pressure of carbon dioxide showed no significant differences between the three groups before and at one month and one year after operation (P > 0.05). CONCLUSION: Dust exposure should be avoided after WLL to ensure the treatment outcome.

Man-made mineral fibers and interstitial lung diseases.

PURPOSE OF REVIEW: Manufactured (artificial) fibers represent an important and continuously growing volume among substitutes to natural fibers. A major proportion of the population in an industrialized society has been, is, or will be in contact with these fibers. The fibrous configuration of asbestos is well recognized as being an important parameter in toxicity, and now that of synthetic fibers is also suspected of inducing serious health effects on the respiratory system. There is an ongoing debate about the actual fibrogenic effect of these man-made mineral fibers (MMMFs) in humans. RECENT FINDINGS: Several case reports have demonstrated the biopersistance of MMMFs in the lung of workers who were exposed to rock wool or fiberglass for long periods of time and were diagnosed with interstitial pulmonary fibrosis. A 20-year follow up also identified refractory ceramic fibers in workers' lung tissue, with significant association between cumulative fiber exposure and radiographic pleural changes. Newly emerging man-made fiber industries appear to induce new types of occupational diseases. SUMMARY: Exposure of workers in MMMFs production plants is correlated to high risk for developing pneumoconiosis. Large epidemiological studies are needed in order to determine dose metrics for risk assessment and management.

Lung response after subchronic glass fiber intratracheal instillation: an experimental study on rats.

The aim of the study was to identify the effects on the lung after subchronic glass fiber intratracheal instillation study on rats. We evaluated the toxicological effects on the lung: persistent inflammatory reaction, cell proliferation, and pulmonary fibrosis on histopathological examination. We performed a glass fiber intratracheal instillation study on total 32 Wistar rats. The animals were divided into four groups: three test groups exposed to different doses of glass fiber and one control group. One week after the end of the exposure period, all animals were euthanized. The histopathological examination of the lung performed in this study followed both distribution of the lesions through the multilevel biopsies that were taken and the inflammatory profile using both hematoxilin-eozin and Sirius red staining. The inflammatory lesions described for the first group were minimal/slight (grade I) and the total score was between 0 and 10 points (mean value = 3). For the second group, the inflammatory lesions were moderate/marked (grade II) with discrete collagen proliferation and discrete fibrosis and the total score ranged between 11 and 20 points (mean value = 11,250). For the third group, the described inflammatory lesions were massive with total score ranging between 21 and 30 points with collagen deposition, pulmonary and pleural fibrosis, and lung emphysema (mean value = 21,750) and no lesion in control group (with statistically significant difference P ≤ .001). This study of fiber glass intratracheal instillation of three different doses demonstrates that exposure to fiber glass is responsible for the development of persistent inflammatory response and a large range of hystopathological lesions which correlate to the administered dose.

Small mine size is associated with lung function abnormality and pneumoconiosis among underground coal miners in Kentucky, Virginia and West Virginia.

OBJECTIVES: To describe the prevalence of lung function abnormality and coal workers' pneumoconiosis (CWP) by mine size among underground coal miners in Kentucky, Virginia and West Virginia. METHODS: During 2005-2012, 4491 miners completed spirometry and chest radiography as part of a health surveillance programme. Spirometry was interpreted according to American Thoracic Society and European Respiratory Society guidelines, and radiography per International Labour Office standards. Prevalence ratios (PR) were calculated for abnormal spirometry (obstructive, restrictive or mixed pattern using lower limits of normal derived from National Health and Nutrition Examination Survey (NHANES) III) and CWP among workers from small mines (≤50 miners) compared with those from large mines. RESULTS: Among 3771 eligible miners, those from small mines were more likely to have abnormal spirometry (18.5% vs 13.8%, p<0.01), CWP (10.8% vs 5.2%, p<0.01) and progressive massive fibrosis (2.4% vs 1.1%, p<0.01). In regression analysis, working in a small mine was associated with 37% higher prevalence of abnormal spirometry (PR 1.37, 95% CI 1.16 to 1.61) and 2.1 times higher prevalence of CWP (95% CI 1.68 to 2.70). CONCLUSIONS: More than one in four of these miners had evidence of CWP, abnormal lung function or both. Although 96% of miners in the study have worked exclusively under dust regulations implemented following the 1969 Federal Coal Mine Safety and Health Act, we observed high rates of respiratory disease including severe cases. The current approach to dust control and provision of safe work conditions for central Appalachian underground coal miners is not adequate to protect them from adverse respiratory health effects.

Using volume-time curves with real-time three-dimensional echocardiography to analyze right ventricular function in patients with pneumoconiosis.

We evaluated right ventricular function in patients with pneumoconiosis using real-time three-dimensional echocardiography (RT3DE). A total of 80 consecutive patients were prospectively recruited, 44 of whom were diagnosed with pneumoconiosis, and the remaining 36 age- and gender-matched healthy volunteers served as the control group. All patients underwent both 2D and 3DE. The tricuspid regurgitation pressure (TRPG), right ventricular anterior wall thickness and range of motion, right ventricular posterior wall thickness and range of motion, right ventricular end-diastolic volume, right ventricular end-systolic volume, and right ventricular ejection fraction (RVEF) were measured. The RVEF of healthy volunteers ranged from 50 to 78%, while the RVEF of pneumoconiosis patients ranged from 29 to 73%. TRPG influenced RVEF by 77.3% (P = 0.006) and showed a negative correlation (r = -0.643, P < 0.01). Volume-time curves (VTC) of patients with pneumoconiosis showed more troughs (low stroke volumes) than the VTCs of normal subjects. Evaluation of right ventricular function in patients with pneumoconiosis using RT3DE can provide additional clinical information.

Pneumoconiosis in dental technicians: HRCT and pulmonary function findings.

BACKGROUND: Pneumoconiosis is a form of diffuse interstitial lung disease, often resulting from occupational exposures. As dental prosthetic technicians (DPTs) build prostheses, they are exposed to many chemical materials that increase their risk of developing pneumoconiosis. AIMS: To document pulmonary function and prevalence of pneumoconiosis in DPTs. METHODS: A cross-sectional study of DPTs working in prosthetic laboratories who underwent pulmonary function test and high-resolution chest computed tomography (HRCT) scanning. RESULTS: There were 76 participants and pneumoconiosis was diagnosed in 46%. The most commonly seen radiological finding was round opacities, present in 38%. Agreement among HRCT readers was moderate to good. As defined by HRCT, emphysema was diagnosed more often in those with a longer occupational history or a history of smoking, and low carbon monoxide diffusion capacity (DLCO), but not in those with pneumoconiosis. Forced expiratory rate and DLCO were significantly lower in those who had worked 16 years or more (all P < 0.05). DLCO values were significantly lower in technicians with emphysema and in current smokers (all P < 0.01). Round opacities were also present in a substantial proportion of DPTs who had 15 years or less exposure. Because HRCT is able to detect radiological changes of occupational lung disease very early, the prevalence of pneumoconiosis in our participants was quite high. CONCLUSIONS: Pneumoconiosis identified by HRCT was present in almost half of DPTs surveyed. Appropriate education and workplace protection should be given to DPTs in order to prevent exposure to hazardous materials in dental prosthetics laboratories.

[Relationship between recovery levels of pulmonary surfactants and lung compliance after whole-lung lavage].

OBJECTIVE: To investigate the relationship between the recovery levels of pulmonary surfactants (PS) and lung compliance after whole-lung lavage. METHODS: Patients with pneumoconiosis in different stages (healthy subjects, stage I, and stage II, n = 10 for each group) were selected. The recovery levels of PS and lung compliance at different time points after whole-lung lavage were determined, and their relationship was analyzed. RESULTS: Before whole-lung lavage and at 0, 10, 30, 60, 90, and 120 min after the operation, the lung compliance levels were 39.5±6.7, 28.3±5.6, 31.5±5.2, 37.6±4.4, 38.0±5.3, 38.7±5.5, and 39.2±5.3 ml/cm H2O for healthy subjects, 38.8±5.1, 25.1±6.1, 28.4±6.8, 30.5±5.9, 36.3±5.5, 37.3±5.4, 38.2±4.5, and 38.8±5.1 ml/cm H2O for patients with stage I pneumoconiosis, and 32.9±6.1, 20.3±6.0, 24.3±5.4, 25.1±5.4, 26.8±5.8, 27.8±4.8, and 32.8±4.5 ml/cm H2O were for patients with stage II pneumoconiosis. It was observed that in patients with pneumoconiosis, the lung compliance levels showed a declining trend along with the increasing stage, reaching the lowest level in stage II patients; comparison between groups indicated a significant difference (P < 0.05). For healthy subjects, 30 min was needed for restoring lung compliance to its preoperative level, while 60 and 120 min were needed for stage I and stage II patients, respectively. Compared with that at 0 min after operation, PS levels were elevated significantly at 10 min after operation in all patients (P < 0.05), whereas for stage I and stage II patients, the PS levels at 30 min after operation were significantly higher than that at 10 min (F = 4.27, P < 0.05; F = 20.40, P < 0.05). For all patients, the PS levels at 60 min after operation were significantly higher than those at 10 and 30 min (P < 0.05). After whole-lung lavage, the PS levels in all patients were restored to a large extent within 10∼30 min, but the recovery of lung compliance needed 30∼ 90 min. CONCLUSION: After whole-lung lavage, the lung compliance declines obviously, but recovers gradually afterwards; the higher stage suggests a longer recovery. The recovery of lung compliance needs a longer time than that of PS.

[Effect of smoking on the microRNAs expression in pneumoconiosis patients].

OBJECTIVE: To investigate the effect of smoking on the microRNAs (miRNAs) expression in pneumoconiosis patients. METHODS: Real-time qPCR was used to measure the expression levels of miR-21, miR-200c, miR-16, miR-204, miR-206, miR-155, let-7g, miR-30b, and miR-192 in 36 non-smoking patients with pneumoconiosis and 38 smoking patients with pneumoconiosis, and the differences in expression levels between the two groups were evaluated by two-independent samples t-test. RESULTS: The expression of miR-192 in serum showed a significant difference between non-smoking and smoking pneumoconiosis patients (P < 0.05), and it decreased gradually in smoking patients with stage I and II pneumoconiosis. In the serum of all pneumoconiosis patients, the expression level of miR-16 was the highest, while the expression level of miR-204 was the lowest. CONCLUSION: Pneumoconiosis patients have differential expression of miRNAs in serum, and smoking has an effect on the miRNAs expression in pneumoconiosis patients.

Is an individual prediction of maximal work rate by 6-minute walk distance and further measurements reliable in male patients with different lung diseases?

BACKGROUND: In patients with chronic lung diseases, the work rate for endurance training is calculated by the maximal work rate (Wmax). Because the assessment bears side effects, a prediction by easier accessible tests would be of practical use. OBJECTIVE: We addressed the reliability of predicting Wmax on the basis of the 6-min walk distance (6MWD) test and a set of further parameters in patients with different lung diseases. METHODS: Baseline data of a longitudinal study including 6MWD, Wmax, peripheral muscle force, lung function, fat-free mass and dyspnea (Modified Medical Research Council score) of 255 men with occupational lung diseases (104 asthma, 69 asbestosis, 42 silicosis, 40 chronic obstructive pulmonary disease) were evaluated. RESULTS: 6MWD correlated with Wmax (r = 0.51, p < 0.05). The product of 6MWD and body weight, in particular fat-free mass, led to an improvement in the correlation of Wmax with 6MWD. Muscle force, lung function and Modified Medical Research Council score correlated moderately but significantly with Wmax (p < 0.05 each). The maximum correlation gained by including 6MWD and further parameters in the prediction equations was r = 0.76 in patients with obstructive lung function impairment and r = 0.61 in asbestosis patients. The residual standard deviations of Wmax predicted by the calculated equations ranged between 20 and 28 W, and the 95% prediction intervals of Wmax ranged between ±47 and ±65 W. CONCLUSIONS: A reliable prediction of individual Wmax by 6MWD or related measures and therefore a replacement by other tests is not possible. Nevertheless, it may be useful for the comparison of average values in epidemiological and clinical studies.

[Effects of whole lung lavage on pulmonary function and exercise capacity in patients with pneumoconiosis].

OBJECTIVE: To investigate the effects of whole lung lavage (WLL) on the pulmonary function and exercise capacity in patients with pneumoconiosis. METHODS: Forty-one patients with pneumoconiosis who quit dust-exposed work not more than 6 months before underwent WLL. Clinical symptom assessment, pulmonary function test, and cardiopulmonary exercise test were performed before and one week after WLL, and the results were compared. RESULTS: The patients with pneumoconiosis showed no significant changes in clinical symptoms after WLL. At one week after WLL, the patients with pneumoconiosis showed nonsignificant increases in forced vital capacity, forced expiratory volume in one second (FEV1.0), and percent predicted FEV1 (P > 0.05); peak oxygen uptake (peak VO2) increased from 2140.6 ± 353.2 ml/min before WLL to 2374.6 ± 362.4 ml/min after WLL, percent predicted peak VO2 increased from 82.2 ± 13.7% before WLL to 91.0 ± 14.0% after WLL, peak VO2/kg increased from 30.6 ± 3.5 ml/min×kg before WLL to 34.2 ± 3.7 ml/min×kg after WLL, and ventilatory equivalent for carbon dioxide decreased from 30.6 ± 3.1 before WLL to 26.1 ± 2.7 after WLL (P < 0.05). CONCLUSION: WLL can remarkably improve the oxygen uptake and ventilatory efficiency in patients with pneumoconiosis during exercise, so it can improve the exercise capacity of these patients.