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PubMed1998

[Application and analysis of biochemical indices for the evaluation of antisilicosis treatment. Study on anti-silicosis therapy and its evaluation research group].

The levels of serum Ceruloplasmin (Cp), Superoxide dismutase (SOD) and IgG of 296 silicosis patients treated by tetrandrine, polyvinylpridine-N-Oxide, hydroxypiperaquinoline phosphate and aluminium citrate were measured. Sera were collected before and after the 1st, 3rd and 6th therapy courses. 144 Silicosis patients without treatment were observed as controls. The levels of these three indices decreased by the end of treatment. The levels of SOD were fluctuated, which were increased after the 3rd course, but decreased after the 1st and 6th courses. The decrease of Cp, SOD and IgG consisted with the clinical effectiveness of the treatment, indicating that Cp, SOD and IgG were appropriate biochemical indicators for the evaluation of antisilicosis drugs. The quality control and the statistics standardization for data analysis are important.

Alkaloids↗
PubMed2000

A distinct mutational spectrum of p53 and K-ras genes in lung cancer of workers with silicosis.

Crystalline silica was recently classified as a human carcinogen by the International Agency for Research on Cancer (IARC). However, the direct genotoxic effect of silica in humans remains unclear. We examined the p53 and K-ras gene mutations in lung cancer in workers with silicosis (LCWS). DNA was extracted from paraffin-embedded tissues and examined by PCR-RFLP, PCR-SSCP, and DNA sequencing. The mutation frequencies of p53 gene were high, but the mutation distributions in exons and among the histological types of LCWS differed from those of common (i.e., not silicosis-related) lung cancer. Furthermore, no mutations in codon 12 of K-ras gene (predominant in common lung cancer) were found in LCWS. These findings in the mutational spectrum support a carcinogenic effect of silica dust at the DNA molecular level.

DNA Mutational Analysis↗
PubMed2000

In vivo experimental model for silicosis.

The selection of an experimental model for silicosis requires a thorough understanding of many pulmonary parameters specific to the experimental animal (e.g., clearance time, penetration curves, anatomical differences), as well as the strain's sensitivity to different conditions. The pulmonary response of three rat strains (i.e., Fischer 344, Sprague-Dawley, and Wistar) to silica dust was compared using two methods of exposure: intratracheal injection and inhalation. The test period lasted 3 months for injection and 6 and 12 months for inhalation. The histological study of the lung revealed a distinct nodular reaction in Sprague-Dawley and Wistar strains. Intratracheal injections led to the development of fibrotic nodules in Wistar rats, whereas such silicotic nodules were infrequent in injected Fischer 344 rats, and almost absent when exposure was by inhalation. Sprague-Dawley and Fischer 344 rats showed frequent thickening and metaplasia of the alveolar walls near the terminal bronchioles. This tendency was particularly pronounced in rats exposed by inhalation (especially Fischer 344 rats). Macroscopic examination (wet lung weight) and biochemical dosing (lung silica, hydroxyproline, and lipid content) revealed an increase in the various parameters examined in Sprague-Dawley rats relative to the other two strains, regardless of the type of exposure. The histological examination, however, leads us to conclude that the Wistar rats offer the best experimental model for silicosis, because their pulmonary reaction is more characteristic of the human condition than that of the other two strains.

Animals↗
PubMed2000

Pulmonary histopathology and alteration in cellular pattern of bronchoalveolar lavage fluid in experimental silicosis.

Pathogenesis of silicosis is still being evaluated. Cellular and histopathological changes in lung following acute and chronic exposure of quartz in rats have been investigated. Inbred wistar rats were given single intratracheal injection of quartz (10 mg in 0.05 ml saline) in groups of acute model, and inhalation of quartz (40 mg/m3 with air flow 5 l/hr in a simulation chamber, 6 hr/day) in groups of chronic model. The control groups were exposed to vehicles only. Rats were sacrificed on day 3, 5 and 7 of intratracheal injection and after 2, 4 and 8 weeks of inhalation. Total and differential cell counts (TC and DC) were performed in bronchoalveolar lavage fluid (BALF). Histopathology was done in the lungs. There was significant (P < 0.001) increase in TC and significant (P < 0.001) changes in percentage of inflammatory cell counts on DC in the BALF of silicotic rats. Histopathology showed progressive inflammatory and fibrotic response in quartz exposed lungs in both acute and chronic models. The results indicate duration dependent inflammatory changes in lungs of both the models. Changes in cell counts precede the histopathological changes and may serve as early biological marker for detection of silicosis.

Acute Disease↗
PubMed1975

A study of the age factor in experimental silicosis in rats.

In order to study the progress of pulmonary silicosis in rats of different ages, intratracheal injections of (50 mg/150 g body weight) quartz dust of particle size less than 5 mu were given as a single dose and studies were made over a period of 180 days. The pulmonary macrophage reaction and phagocytosis in the younger age group of rats was different from that in the older animals at 30 days postinoculation. The formation of silicotic nodules was delayed in the younger animals. They consisted of thick reticulin fibers and some collagen fibers; in the older group of rats large silicotic nodules with dense collagination developed towards the termination of the experiment (180 days). The present results indicate a possible direct relationship between age and the development of experimental pulmonary silicosis in rats.

Age Factors↗
PubMed2001

[A case of IgA nephropathy associated with silicosis].

A 51-year-old male who had been working as a building wrecker for 20 years, was admitted to our hospital in June 1999 for proteinuria and hematuria examination. He started this work in 1978. Twelve years later, severe coughing and bloody sputum began and he was diagnosed as having silicosis in 1995. Urinalysis on admission showed proteinuria(294 mg/day), microhematuria(20-30/hpf), RBC cast and granular cast. High serum IgA(770 mg/dl) and high serum interleukin-6(IL-6) (3,280 pg/dl) were found. A renal biopsy showed mild mesangial matrix expansion and mesangial cell proliferation with IgA deposition, which was diagnosed as IgA nephropathy. Chest X-rays showed multiple small nodular lesions on both lung fields indicating silicosis. In Nov. 1999, he resigned from his job as a building wrecker because of increasing coughing and bloody sputum associated with body weight loss. Within 3 months after stopping this work, coughing and bloody sputum disappeared and the abnormal urinalysis findings returned to normal. Serum IgA and serum IL-6 data improved to 462 mg/dl and 2.5 pg/dl, respectively. It is suggested that silicon exposure might be related to the pathogenesis of IgA nephropathy in this patient.

Biomarkers↗
PubMed1975

[Silicosis associated with scleroderma].

Such an association would not appear to be fortuitous since scleroderma is commoner in male miners than in women in general, whilst the predominance of the disease in the latter group is well known. The picture is that of generalised scleroderma without any special characteristics. Silicosis usually precedes the scleroderma. In general, the onset of scleroderma alters the chest X-ray appearance with the development of diffuse, non-cavitated macro-nodular opacities localised in the lower two-thirds of the lungs and in particular at the bases, without absolute symmetry. Several hypotheses may be advanced to explain this association. Irritation by dust in the presence of a particular underlying terrain may cause silicosis and the same terrain may be associated with the development of scleroderma. A second possibility is that of immune phenomena secondary to the pneumoconiosis which favourise the development of scleroderma.

Aged↗
PubMedDate not supplied

Impairment of pulmonary mixing in simple and complicated silicosis.

Two simple indices of pulmonary mixing (helium mixing time in a closed circuit, and mixing ventilation) were measured in 274 patients (mostly miners) with silicosis, aged 50 years or less (mean 42.4 years); the results were analysed in respect to silicosis category and type, presence of co-existent chronic bronchitis and ventilatory performance, and were compared to those of a group of normal subjects to assess statistical significance. The average results for the whole group were 5.81 min for mixing time (tmix) and 62.3 1 for mixing ventilation (Vmix), representing 1.8 times and 2.4 times the normal, respectively; the results were higher for patients with co-existent chronic bronchitis within each radiological category, except the last ("C" opacities), but the differences were significant only for patients with small opacities and with "suspect pneumoconiosis". Among patients with small rounded opacities the co-existence of healed tuberculosis (apical fibrous nodules) or of other X-ray changes did not influence the pulmonary mixing; no difference was found between the three types of small opacities. A slight tendency towards lower values in patients with early conglomeration ("A" opacities) allows the suggestion of conglomeration starting in "slow" lung spaces. The best results were those of patients with normal ventilatory function followed by those with a restrictive and then by those with an obstructive ventilatory impairment. The most severe mixing disturbance was found among patients with chronic bronchitis and obstructive defect with "suspect pneumoconiosis", who are not covered by occupational disablement compensation.

Adult↗
PubMedDate not supplied

Cytokine polymorphisms in silicosis and other pneumoconioses.

Silicosis and coal workers' pneumoconiosis are complex multifactorial lung diseases whose etiopathogenesis are not well defined. It is generally accepted that fibrotic lung disorders are mediated by macrophage-derived cytokines and growth factors. There is evidence showing a crucial role for tumor necrosis factor-a (TNF-alpha) and interleukin-1 (IL-1) in inflammation caused by silica dust and in the transition from simple to progressive massive fibrosis. In this review we discuss genetic polymorphisms responsible for regulating the production of these proinflammatory cytokines and their role in modifying silicosis severity.

Genotype↗
PubMed2003

Silicosis in a housewife.

Silicosis is an occupational respiratory disease caused by inhaling respirable crystalline silica dust. We report the case of silicosis in a 50-year-old woman that presented with pulmonary fibrosis and later developed pulmonary tuberculosis. Her condition is believed to be due to inhalation of dust produced by scrubbing a silica rich surface during usual daily housework.

Female↗
PubMed1992

Clinical observations with Paxirasol aerosol in patients suffering from chronic bronchitis accompanying silicosis.

Paxirasol aerosol applied in daily 3 x 5 puff doses in the treatment of silicosis patients is found to be a well tolerated drug form. In the course of the 21-day therapy especially coughing and chest pain were moderated, but the product also controlled, the catarrhal coat formation on the mucosa. It influenced abundant expectoration and dispnoea beneficially. During the therapy the laboratory parameters did not change. The objective respiratory parameters improved but the change was non-significant. Paxirasol aerosol is found useful in the treatment of chronic bronchitis accompanying silicosis. Evaluable side-effects were not registered.

Administration, Inhalation↗
PubMed1992

[Experimental research on the efficacy of terrilytin in silicosis].

Experimental silicosis was induced by quartz-containing dust administered intratracheally to Wistar male rats. Proteoclastic enzymes terrilytine was found to arrest pulmonary fibrosis, which was proved by inhibited development of silicotic granulomas and their lowered fibrosis. Terrilytine was most effective when inhaled in a dose of 0.08 PU per rat. Injected intraperitoneally, terrilytine in the dose elevated from 0.1-0.2 to 0.3 PU inhibited fibrosis developing in the presence of marked serous desquamative alveolitis. Incorporation of the enzyme in the cholesterol-lecithin liposomes prevents this side effect in the lungs. Liposomes injected intraperitoneally do not influence the development of pulmonary fibrosis in silicosis.

Adjuvants, Immunologic↗
PubMed1992

Standard imaging in silicosis and coal worker's pneumoconiosis.

Silicosis and coal worker's pneumoconiosis (CWP) are two relatively common occupational diseases. Silicosis is the most common pneumoconiosis in the United States. It results from inhalation of the particulate form of quartz or other crystalline forms of silicon dioxide with a diameter of less than 5 micrograms. CWP is the result of inhalation of carbon particles. Pathologic features of the two diseases differ, yet their radiologic features are identical. Simple pneumoconiosis is characterized by multiple small rounded opacities of 1 to 5 mm in diameter and with a bias for the upper lung zones. Complicated pneumoconiosis results from confluence of small opacities into large opacities that form conglomerate masses or progressive massive fibrosis.

Coal Mining↗
PubMed1992

Computed tomographic evaluation of silicosis and coal workers' pneumoconiosis.

The introduction of computed tomography (CT) has modified the radiologic approach to silicosis and coal worker's pneumoconiosis considerably, allowing earlier recognition and more precise characterization of pulmonary abnormalities than chest radiography. An optimal approach to CT recognition requires an understanding of the main physiologic and pathologic features that are known to occur in both pneumoconioses. This report focuses on the most common CT features of simple and complicated forms of silicosis and coal worker's pneumoconiosis as well as on the optimal scanning protocol. The respective roles of chest radiographs and CT scans in the recognition of pneumoconiosis and follow-up of exposed workers are discussed.

Coal Mining↗
PubMed2004

[Expression and role of early growth response gene-1 in experimental silicosis of rat].

OBJECTIVE: To study the expression and location of early growth response gene-1 (Egr-1), transforming growth factor-beta(1) (TGF-beta(1)), fibronectin (FN) in silicotic rat and to discuss the role of Egr-1 in the development of silicosis. METHODS: Silicotic animal model of rat was established, and the expressions of Egr-1, TGF-beta(1), FN in various lung cells of silicotic rat were analysed by using immunohistochemical technique (SP) and the image analysis. RESULTS: The expressions of Egr-1 in bronchial epithelial cell, pulmonary macrophage, alveolar epithelium cell and interstitial cell in lung silicotic tissue (gray values: 118.58 +/- 5.65 - 168.52 +/- 5.67) were higher than those of controls (gray values: 166.23 +/- 5.23 - 188.12 +/- 8.35) during 1 - 28 days, and the expression was mainly in nucleus; the expressions of TGF-beta(1) in these cells (gray values: 123.49 +/- 5.65 - 170.24 +/- 3.56) were also higher than those of controls (166.53 +/- 6.25 - 198.56 +/- 4.53), and the expression was mainly in cytoplasm. The expressions of FN in bronchial epithelial cell, pulmonary macrophage and alveolar epithelial cell (gray values: 150.32 +/- 6.54 - 201.54 +/- 7.38) were lower, while those in interstitial cell (gray values: 121.43 +/- 5.65 - 167.55 +/- 6.35) were higher than those of controls. The changes of TGF-beta(1) and Egr-1 expression level in bronchial epithelial cell, pulmonary macrophage, alveolar epithelium cell and interstitial cell were synchronous during the experiment (1 - 28 days). Both of them were correlated with each other (r = 0.61, P < 0.01), while the expression of FN was not correlated with Egr-1, but correlated to TGF-beta(1) in interstitial cell (r = 0.46, P < 0.01). CONCLUSION: Silicon dioxide could up-regulate the expression of nuclear transcription factor Egr-1 in several kinds of cell in lung. The activated Egr-1 may coordinate the expression of TGF-beta(1) and FN to regulate the development of silicosis.

Animals↗
PubMedDate not supplied

Silicosis related changes in serum copper.

To ascertain the diagnostic and prognostic value of serum copper in silicosis, this trace element was determined in 68 patients (all males), aged varied between 20 and 60 years (mean age 44 +/- 2.3 years). The same determination was carried out in a control group of 35 healthy subjects. The patients were distributed into three subgroups according to the evolutive stage of disease. The mean value of serum copper increased gradually from stage to stage reaching in stage III the highest copper mean value (p < 0.01). Serum copper concentrations also increased with the severity of the disease. These changes suggest that copper is directly responsible for the lung changes in silicosis and can be used as an indicator of the severity of the inflammatory reaction.

Adult↗
PubMed1992

Screening of pulmonary hypertension in chronic obstructive pulmonary disease and silicosis by discriminant functions.

The aim of our prospective multicentric study was to develop a screening method for pulmonary hypertension in patients with chronic lung diseases. We investigated 710 patients in 10 hospitals: 315 males and 109 females with chronic obstructive pulmonary disease, and 286 males with silicosis. Manifest pulmonary hypertension was defined as pulmonary artery pressure greater than 20 mmHg (2.7 kPa) at rest. The multivariate statistical method used was a stepwise discriminant analysis. In males with chronic obstructive pulmonary disease, the diameter of the right descending pulmonary artery, forced expiratory volume in one second (FEV1) arterial oxygen tension (PaO2) at rest, and age turned out to be relevant for discrimination of groups with and without manifest pulmonary hypertension. For females the FEV1/FVC (forced vital capacity) ratio replaced the absolute value of FEV1 in the calculated discriminant function. In females, sensitivity and specificity were below 80%. In males, both were distinctly above 80%. In silicosis, the diameter of the right descending pulmonary artery was much less important, since it could frequently not be measured precisely. In these cases, precision of the prediction of about 80% could only be obtained by combined evaluation of spirometry, PaO2 during exercise, and body plethysmography. The calculated discriminant functions are appropriate for screening patients with risk of pulmonary hypertension. For different chronic lung diseases, and for both sexes, different combinations of parameters are relevant. The method is recommended to select patients who should undergo an invasive examination of pulmonary haemodynamics.

Discriminant Analysis↗
PubMedDate not supplied

Chronic necrotising pulmonary aspergillosis: a rare complication in a case of silicosis.

Chronic necrotising pulmonary aspergillosis (CNPA) is a rare complication of silicosis whose diagnosis requires a high index of suspicion as it mimics tuberculosis. We report a case of a 52-year-old male with a long history of silica dust exposure and progressively increasing dyspnoea for the past eight years, productive cough, fever, weight loss for past three months and hemoptysis for preceding three weeks. Based on the clinical, radiological and microbiological evidence, he was diagnosed to be a case of CNPA with aspergilloma complicating silicosis.

Aspergillosis, Allergic Bronchopulmonary↗