Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0037116 (silicosis)
 1,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In recent years, with the aging of patients with pneumoconiosis, autoimmune diseases as a complication have been observed. One of the reasons for this may be that autoimmune diseases are prone to develop among the elderly. On the other hand, it has been reported that dust itself, such as silica for example, has adjuvant effect. A review of the recent literature published in Japan and abroad was made to clarify the relationship between pneumoconiosis and autoimmune diseases and the following results were obtained. 1) Disorders which accompany pneumoconiosis: Scleroderma, rheumatoid arthritis, systemic lupus erythematosus (SLE), and disorders of the kidney and liver have been reported. In Japan, about 30 cases of pneumoconiosis accompanied with autoimmune diseases have been reported. In many of the reports, patients with pneumoconiosis and scleroderma have a past history of exposure to silica. In both case studies and case control studies, patients with rheumatoid arthritis and history of silica exposure are prone to develop pneumoconiosis. 2) Immunological studies of patients with pneumoconiosis: As for humoral immunity, elevation of polyclonal gamma-globulin, especially IgG, has been often reported together with high positive rate of autoantibodies such as antinuclear antibodies. In cellular immunity, decreased delayed type skin reaction and decreased CD4/8 ratio have been reported. In human leukocyte antigen (HLA) typing the elevated frequency of DR4 has been reported. In the study of BAL increased production of superoxide anion O2- by alveolar macrophages has been observed. 3) EXPERIMENTAL STUDIES: Silica is well known for its toxicity to cells and also for its adjuvant effect. In the German Democratic Republic, patients with scleroderma and history of long term silica exposure are recognized as patients with occupational disease even though pneumoconiosis is not clearly demonstrated on X-ray film. It is difficult from this review to nrake a definite conclusion regarding the relation between silicosis and autoimmune diseases. There is a need to repeat this review of the literature on autoimmune diseases and pneumoconiosis in the near future.
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PMID:[Relationship between autoimmune diseases and pneumoconiosis]. 140 2

We could identify, via bronchoalveolar lavage, crystals in the lavage fluid and in the alveolar macrophages. Thus, BAL could be another method for diagnosing silicosis patients.
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PMID:Silicosis in ceramic-industry workers with particular reference to the diagnostic value of bronchoalveolar lavage. 179 86

The purposes of this study were (1) to investigate the chronology of events in cellular and biochemical changes thought to be important in the development of silicosis, (2) to relate these to changes in lung function and radiograph, and (3) to evaluate the relation of quartz exposure and retention to individual response leading to early silicosis. Thirty-six sheep were exposed by repeated intratracheal infusion at 10-day intervals to 100 mg Minusil-5 in 100 ml saline (Si group), and 10 sheep were exposed at the same intervals to 100 ml saline (control). All sheep were investigated at 3-month intervals by chest radiograph, lung function, and lung lavage. At month 9, chest radiograph score of parenchymal opacities was significantly increased at 2.8 +/- 0.6 versus 0.4 +/- 0.4 in the Si group (p less than .05), establishing early radiologic silicosis. Lung function was significantly altered with reduction in lung compliance, vital capacity, and diffusion capacity (p less than .05). Lung lavage cellularity revealed significant increase in total cells (X 2.5), macrophages (X3), and neutrophils (X3). Albumin in BAL remained at the control level. Fibronectin production was significantly increased, as was the fibroblast growth activity, without significant change in procollagen 3 at this early stage of disease. Total phospholipids were significantly elevated in the Si-exposed sheep, and the profile demonstrated an increase in all the phospholipid components. Spontaneous release of hydrogen peroxide by alveolar cells was not increased, but in the presence of phorbol myristate acetate (PMA) higher levels of peroxide were found in the quartz-exposed sheep (p less than .05). The cellular and biochemical alterations of lung lavage preceded other changes. At month 12, there were good correlations (r greater than .49, p less than .001) between parameters evaluating related phenomena but poor correlations between measurements evaluating different aspects of the disorder. To investigate the heterogeneity in the individual response of sheep to the same exposure (susceptibility), individual quartz retention levels at month 12 were measured and found to correlate well with individual parameters of disease activity. We concluded that in early silicosis of sheep, cellular and biochemical changes in lung lavage preceded derangements of pulmonary function and radiographic abnormalities. Thereafter, parameters of lung lavage, lung function, and radiograph were significantly interrelated, but for a given exposure the degree of quartz retention appeared to determine the intensity of the silicotic process.
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PMID:Quartz exposure, retention, and early silicosis in sheep. 254 36

1. Serial bronchoalveolar lavages were performed on a subhuman primate (Macacus cynomolgus) in order to give an experimental model for silicosis. 2. We have measured glycosidases, proteases, peroxidase and antiproteases of the BAL fluids from seven normal monkeys. 3. The results obtained were similar to those found in human control BAL fluids. 4. For monkeys, the repetition of the bronchoalveolar procedure does not seem to have an important influence on the values obtained. 5. The present results will now permit sequential follow up studies during the course of experimental silicosis.
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PMID:Comparison of hydrolases, peroxidase and protease inhibitors in bronchoalveolar fluid from Macacus cynomolgus and human controls. 332 59

Data on the cytology of BAL performed on 8 silicosis and 5 asbestosis patients with different degrees of radiological profusion and functional impairment are examined. The prevalently neutrophilic alveolitis reported in the literature in these forms of pneumoconiosis is confirmed, while differences were found between the percentage of lymphocyte subpopulations in the two diseases.
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PMID:[Data on cellular subpopulations in bronchoalveolar lavage in silicosis and asbestosis patients. Case contribution]. 367 Jun 90

Risk groups with regard to bronchopulmonary precancerous and tumor diseases of occupational origin can be deduced from current occupational disease statistics. Most prominent are those working with asbestos. Each year about 250 asbestos-associated bronchial carcinomas and 400 mesotheliomas are recognized and compensated; the tendency is increasing. Because of the long latency time, the frequency peak will probably be reached in about 15 years in spite of the prohibition of asbestos usage. The second place is probably taken by malignomas among the underground uranium mine workers in Thuringia and Saxony (SDAG Wismut). Next come bronchial carcinomas with silicosis (carcinoma in scar tissue) after exposure to chromium(VI) and arsenic compounds as well as various other chemicals and metals. Dose-activity relationships are significant for all occupational carcinogenic agents, as there are also often syncancerogenic influences (especially smoking). From the data on previous loading, high risk groups, for example, among the insulation workers exposed to asbestos or uranium miners in the so-called "wild years", can be defined. A suitable screening method for the detection of bronchopulmonary tumors in the early stages has not yet been established. Medical checkups for the respective risk groups concentrate on the early X-ray detection of circular foci. As shown by recent studies, cytological sputum diagnosis, (fluorescence) bronchoscopy, and BAL cytology must be employed much more frequently in the high risk groups so that the prognostically more favorable stages of preneoplasm and carcinoma in situ can be detected and possibly treated curatively. These procedures are currently reaching a considerably higher sensitivity with the help of modern molecular biology techniques (e.g. detection of tumor-associated genetic changes and gene products). This contributes to an improvement in surveillance examinations with increasing detection of the curable early forms of tumors. However, only the further development of primary prevention, i.e. the greatest possible minimization or, if possible, total elimination of contact with carcinogenic agents and the consequent control of occupational protection will lead to a drastic reduction in the occupational risk of cancer.
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PMID:[Bronchopulmonary precancerous conditions and tumors--risk groups from the occupational medicine viewpoint]. 784 56

The cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNFalpha), derived from macrophages and other cells, may promote mononuclear cell inflammation and fibrosis in pulmonary silicosis. C3H/HeN mice were exposed to control air or to an aerosol of 70 mg/m3 cristobalite silica for 5 h/d for 12 days and examined at 2 and 16 weeks after exposure. This exposure resulted in murine silicosis, as manifested by focal mononuclear cell accumulations, diffuse interstitial fibrosis, lymphoid tissue enlargement, recruitment of inflammatory cells into BAL fluid, and increased total lung collagen. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) with designed primers and membrane hybridization with biotinylated cDNA probes were used to assess the abundance of IL-1beta and TNFalpha mRNA. In situ hybridization with digoxigenin-labeled cDNA probes was used to localize gene expression. Persistent overexpression of both IL-1beta and TNFalpha were found at 2 and 16 weeks in the lungs of silica-exposed mice compared with air-sham control mice. IL-1beta and TNFalpha expression localized to individual mononuclear cells in the alveolar spaces, groups of cells within the aggregate lesions, and scattered mononuclear cells in BALT and lymphoid nodules. Thus, cells producing IL-1beta and TNFalpha appear to be intimately associated with the evolving lesions of silicosis, and the lymphoid tissue of the lung may be important in driving the pathogenesis of this disease.
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PMID:Persistent overexpression of interleukin-1beta and tumor necrosis factor-alpha in murine silicosis. 954 46

Silica exposure results in an initially acute inflammatory response followed by chronic fibrotic change. The mechanism for the maintenance of silica-induced inflammation has not been understood yet. In silica-induced acute inflammation and chronic fibrosis, various mediators such as reactive oxygen species, cytokines and growth factors are released. And these substances are suggested to have the regulatory role for the inflammation and fibrosis by possessing the potential to influence apoptosis. To demonstrate the apoptosis as an underlying mechanism for the development of silicosis, in vitro and in vivo models were designed. In in vitro study, we evaluated that apoptotic cell fraction in silica (10, 50 microg/cm2)-treated A549 cells was significantly increased in comparison with control by FACS (fluorescein activated cell sorter). Also genomic DNA from silica (10, 50 microg/cm2)-treated A549 showed DNA ladder formation while control and 1 microg/cm2 groups didn't. In in vivo study, total cell numbers and apoptotic cell numbers of BAL (bronchoalveolar lavage) fluid from silica (10, 20, 40 mg/kg)-instilled rats were significantly higher than control group from 1 week. From these results, we concluded acute and chronic presence of apoptosis may contributes to silica-induced acute inflammation and chronic fibrosis.
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PMID:Silica-induced apoptosis in vitro and in vivo. 1051 Dec 80

Silicosis is characterized by progressive granulomatous and fibrogenic response in the lung. Inhaled crystalline silica (Qt) induces activation of pulmonary macrophages and leukocyte infiltration in the lung of Qt-treated animals. We investigated the role of leukocyte infiltration and L-selectin during the acute phase of inflammation in developing chronic lung injury in Qt-treated rats. Seventy Wistar male rats were treated with a single transtracheal instillation of Qt (25 mg/kg). Rats were treated intraperitoneally with anti L-selectin monoclonal antibody (mAb), F(ab')2 HRL-3 (HRL-3, a blocking mAb), or RF(ab')2 HRL-2 (HRL-2, a non-blocking mAb)for 4 days before and after Qt injection. Administration of HRL-3 reduced approximately 50% of leukocyte infiltration in the BAL, whereas HRL-2 treatment prior to Qt stimulation showed time-dependent increase of BAL leukocytes. CINC and GRO levels as well as peripheral blood cell counts were similar in HRL-2- or HRL-3-treated animals in the first 4 days of the study. Three months after Qt treatment, extensive granuloma-containing macrophages and leukocytes developed in the lung of the HRL-3-treated rats as compared with the HRL-2-treated rats. Ratio of CD4+ to CD8+ T cells in granulomas did not differ between the HRL-3 and HRL-2 groups. Results suggest that an early phase of leukocyte activation was diminished by blocking L-selectin with the antibody, but treatment with anti-L-selectin increased the formation of granulomas in the Qt-treated rats.
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PMID:The role of leukocytes during acute phase inflammation in crystalline silica-induced lung injury. 1159 19

Numerous investigations have been conducted to elucidate mechanisms involved in the initiation and progression of silicosis. However, most of these studies involved bolus exposure of rats to silica, i.e. intratracheal instillation or a short duration inhalation exposure to a high dose of silica. Therefore, the question of pulmonary overload has been an issue in these studies. The objective of the current investigation was to monitor the time course of pulmonary reactions of rats exposed by inhalation to a non-overload level of crystalline silica. To accomplish this, rats were exposed to 15 mg/m3 silica, 6 h/day, 5 days/week for up to 116 days of exposure. At various times (5-116 days exposure), animals were sacrificed and silica lung burden, lung damage, inflammation, NF-KB activation, reactive oxygen species and nitric oxide production, cytokine production, alveolar type II epithelial cell activity, and fibrosis were monitored. Activation of NF-KB/DNA binding in BAL cells was evident after 5 days of silica inhalation and increased linearly with continued exposure. Parameters of pulmonary damage, inflammation and alveolar type II epithelial cell activity rapidly increased to a significantly elevated but stable new level through the first 41 days of exposure and increased at a steep rate thereafter. Pulmonary fibrosis was measurable only after this explosive rise in lung damage and inflammation, as was the steep increase in TNF-alpha and IL-1 production from BAL cells and the dramatic rise in lavageable alveolar macrophages. Indicators of oxidant stress and pulmonary production of nitric oxide exhibited a time course which was similar to that for lung damage and inflammation with the steep rise correlating with initiation of pulmonary fibrosis. Staining for iNOS and nitrotyrosine was localized in granulomatous regions of the lung and bronchial associated lymphoid tissue. Therefore, these data demonstrate that the generation of oxidants and nitric oxide, in particular, is temporally and anatomically associated with the development of lung damage, inflammation, granulomas and fibrosis. This suggests an important role for nitric oxide in the initiation of silicosis.
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PMID:Effect of inhaled crystalline silica in a rat model: time course of pulmonary reactions. 1216 31


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