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Query: UMLS:C0037116 (silicosis)
 1,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The conditions which might favour development of the fibrotic or the lipid component of the pulmonary reaction to inhaled quartz were examined in rats. Smaller particle size and freedom from surface contamination by amorphous silica or iron oxide, status of the animals whether specific pathogen-free or conventional, and the resistance of cell membranes to damage appeared to bear on fibrogenesis. Increased membrane stability by treatment with polyvinylpyridine-N-oxide abolished not only the fibrosis but also the response of type II cells and hence lipidosis. The rate and intensity of quartz deposition may also affect the response, a low concentration inhaled over a long period favouring nodulation. No other manipulations, environmental or pharmacological, succeeded in inhibiting lipidosis to the benefit of fibrosis. Guinea pigs, however, behaved differently, their reaction being characterized by massive alveolar accumulation of dust-bearing macrophages and type II cell hyperplasia but not by lipidosis. The species variation is unexplained but macrophage predominance may represent a phase that later transforms to lipidosis. The experimental findings may have implications for forms of pneumoconiosis other than silicosis.
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PMID:Determinants of pulmonary fibrosis and lipidosis in the silica model. 302 27

Silicon carbide is a widely used synthetic abrasive manufactured by heating silica and coke in electric furnaces at 2400 degrees C. Until recently it had been considered a relatively inert dust in humans and animals. However, several roentgenologic surveys had revealed lesions similar to low-grade silicosis. A recent epidemiological study has revealed a 35% incidence of pulmonary problems. Tissues from three such workers were available for light microscopy. A mixed pneumoconiosis was found, and lesions can be summarized as follows: (a) abundance of intraalveolar macrophages associated with a mixture of inhaled particles including carbon, silicon, pleomorphic crystals, silicon carbide, and ferruginous bodies showing a thin black central core; (b) nodular fibrosis, generally profuse, containing silica and ferruginous bodies and associated with large amount of carbon pigment; (c) interstitial fibrosis, less prominent than the nodular form; (d) carcinoma in two cases. We believe this pneumoconiosis is sufficiently characteristic to be recognized as a distinct entity. The Stanton hypothesis on fiber properties and carcinogenesis could be applied to silicon carbide dust. At present, it appears that the occupational hazard is limited to the manufacturing process and powdered product used in some industries.
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PMID:Pathology of silicon carbide pneumoconiosis. 323 93

The whole contingent of patients, ill with silicosis manifested after interrupting work with dust, registered up to 1984, at the Clinic of Occupational Diseases, Sofia was examined. Analysis was made of the lasting disability of the patients. A study was performed on the relation between group of invalidity and age groups in the newly discovered cases; group of invalidity and length of service at dry drilling; group and diagnosis of the illness in stages; connection between x-ray morphological displays and functional disturbances and group of invalidity. Recommendations are given concerning the basic pneumoconiosis process and its complications and the interrelations between pneumoconiosis disease, chronic bronchitis and pulmonary emphysema.
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PMID:[Characteristics of work capacity of patients with silicosis occurring after stopping their work in exposure to dust]. 344 61

Current topics for occupational and environmental medicine and physiology in the U.S.A., especially in the National Institute for Occupational Safety and Health (NIOSH), and the University of California, San Francisco, are reviewed. Reduction of the rate for occupational lung diseases is one of the national objectives for occupational safety and health in the U.S.A., and NIOSH has rated it as the top disease of ten-leading work-related diseases and injuries. Current topics for occupational lung diseases--asbestosis, byssinosis, silicosis, coal worker's pneumoconiosis, lung cancer, and occupational asthma & hyperreactivity, and for pathophysiology of airway hyperreactiveness and pulmonary edema are discussed.
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PMID:[Current topics for occupational and environmental medicine and physiology in the U.S.A.--with special reference to occupational lung diseases]. 352 79

A diet with low fat content did not influence the lipid level in the lungs and fibrinogenesis values in the development of silicosis in rats, due to the intensification of the lung lipopexic function, that was revealed in the prefibrosis period, using single fat load. A direct correlation of the lung lipopexic function degree in the prefibrosis period with the degree of pneumophibrosis developing afterwards was noted. The optimum time for the study of the rat lung lipopexic function was specified (1.5 h) after single fat load. It is recommended that the lung lipopexic function, as an indirect sign of the degree of the development of proliferative-cellular reactions in the lungs, be investigated in subjects engaged in the work associated with the risk of pneumoconiosis.
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PMID:[Effect of reduced fat content of the diet of the rat and a single fat load on the lipopexic function of the lungs and the development of silicosis]. 356 88

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

This is a study of cancer mortality, cancer incidence, and incidence of lung tuberculosis among cases of silicosis reported to the National Swedish Pneumoconiosis Register during 1959-1977. Two occupational categories were extracted--"mining, tunneling, and quarrying" (n = 284) and "iron and steel foundries" (n = 428), respectively. Control groups were drawn from a national register of persons undergoing periodic health examinations with regard to silicosis risk. The controls were matched for occupation, age, and time of first exposure. The follow-up was performed through record-linkage operations to computerized information in Swedish Death Statistics, Swedish Cancer Register, and the Swedish Tuberculosis Index. End of follow-up was set at December 31, 1980. In cases drawn from mining, quarrying, and tunneling workers seven deaths in lung cancer were observed and two among the controls. Among iron and steel foundry workers the corresponding numbers were 10 and 6. The values for expected numbers, based on general population statistics, were 1.3 and 2.6, respectively, for these two occupational groups. When cancer incidence statistics were used, the case/control ratio for lung cancer was 2.1 for "mining, quarrying, and tunneling" and 0.6 for "iron and steel foundries." There were 29 cases of lung tuberculosis registered among the silicosis cases during the follow-up period. Only one tuberculosis case was observed among the controls. The results demonstrate that persons with silicosis contracted in the mining, quarrying, and tunneling occupations are subject to an increased risk of lung cancer. The risk is observed when both the general population and a closely matched control population from the same occupations are used for values of reference. The results also demonstrate the high risk of persons with silicosis to contract lung tuberculosis.
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PMID:Silicosis and risk of lung cancer or lung tuberculosis: a cohort study. 375 78

This study was conducted through regular pneumonoconiosis examination according to the law on 1,096 employees of medium and small-sized ceramic enterprises in Tokai district in 1981-82. Interview examination with BMRC questionnaire, X-ray examination and measurement of urinary hydroxyproline to creatinine ratio (HOP ratio) were carried out in order to elucidate the relationship between silicosis and urinary HOP ratio and to demonstrate the effect of smoking on pneumofibrosis. Grade of silicosis was classified into five types (0 to 4) based on the Japanese Classification of Radiographs of Pneumoconioses. In evaluating the behavior of urinary HOP ratio, when smoking factor is added in the early grade of pneumofibrosis (type 1 and type 2), collagen decomposition rate is rapidly repressed and fibroplastic conditions develop to the final grade as type 3 and 4, although smoking itself does not seem to induce pneumofibrosis. To exclude the effects of smoking, nonsmoking group was used for measurement of HOP ratio by grade. The HOP ratio in type 0 was lowest and HOP ratio increased in the order of type 1 and type 2. The turning point was found in type 2 and their HOP ratio decreased one after another. The turning point shifted from type 2 to type 3 in the case of non-smokers without any index symptoms by BMRC questionnaire and also shifted to type 1, in the case of non-smokers with them. Shifting of turning point suggests that index symptoms also promote fibroplastic activities.
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PMID:[Behavior of urinary hydroxyproline and the effect of cigarette smoking in silicosis]. 377 97

Four men who mined barytes in Scotland and who developed pneumoconiosis are described. Three developed progressive massive fibrosis, from which two died; and one developed a nodular simple pneumoconiosis after leaving the industry. The radiological and pathological features of the men's lungs were those of silicosis and high proportions of quartz were found in two of them post mortem. The quartz was inhaled from rocks associated with the barytes in the mines. The features of silicosis in barium miners are contrasted with the benign pneumoconiosis, baritosis, that occurs in workers exposed to crushed and ground insoluble barium salts. Diagnostic difficulties arise when silicosis develops in workers mining minerals known to cause a separate and benign pneumoconiosis. These difficulties are compounded when, as not infrequently happens, the silicotic lesions develop or progress after exposure to quartz has ceased.
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PMID:Silicosis in barium miners. 378 42

To study the local distribution of lymphocyte subsets in inorganic dust diseases, bronchoalveolar lavage (BAL) was performed in seven patients with asbestosis, and in 13 patients with mixed dust pneumoconiosis (anthracosidero-silicosis). Lymphocyte subsets in BAL and blood were determined by the monoclonal antibodies OKT3 (pan T), OKT4 (helper/inducer), OKT8 (suppressor/cytotoxic), B1 (B-cells), OKIa (HLA-DR antigens), and Leu-7 (natural killer). The BAL lymphocytes were moderately elevated to 15 +/- 8 percent (mean +/- SD) in mixed dust pneumoconiosis, and even more markedly increased to 28 +/- 21 percent in asbestosis. The OKT4/OKT8 ratio in BAL was significantly increased to 4.5 +/- 2.1 in asbestosis, and significantly reduced to 0.9 +/- 0.8 in mixed dust pneumoconiosis. In blood, the ratio of T-cell subsets remained unchanged, though total lymphocytes were decreased in asbestosis. These results suggest altered cellular immune processes in the lungs of patients with pneumoconiosis and may indicate different immunoregulatory changes depending on the nature of the inhaled dust.
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PMID:Lung and blood lymphocyte subsets in asbestosis and in mixed dust pneumoconiosis. 379 62


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