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Biomedical subjects

J Bignon

Publications and source records attributed to J Bignon.

At least 181 records · Page 10Linked to original sources
PubMed1980

[Efficiency of bronchial and trans-bronchial lung biopsies in 45 cases of sarcoïdosis (author's transl)].

Forty five patients with suspected sarcoïdosis underwent bronchial and trans-bronchial lung biopsies in the course of fiberoptic bronchoscopy. Specific histologic lesions were found in 51% of the bronchial biopsies (23/45) and in 67% of trans-bronchial biopsies (30/45). The combination of these two different technics of biopsy has significantly increased the efficacity of fiberoptic bronchoscopy in the diagnosis of sarcoïdosis (87%: 39/45). [P. < 0,01]. The presence of specific histologic lesions in the trans-bronchial biopsy was independent of the presence or absence of pulmonary parenchyma in the biopsy. The results were classified according to the radiologic stages of the disease. The trans-bronchial lung biopsy, which is described, is well tolerated. Only one complication was observed (partial pneumothorax).

Adolescent↗
PubMed1979

Asbestos risk among full-time workers in an electricity-generating power station.

A matched survey of 55 full-time workers probably exposed to asbestos in an electricity-generating power station (exposed group) and of 53 unexposed workers in an automobile plant has been conducted. The asbestos risk in the power station was confirmed by the presence of airborne fibers in the range 0.1--6000 X 10(-9) g/m3 in the air sampled during the survey period and by the presence of FB in the sputa of 32.7% of the workers. The following parameters were significantly related to asbestos exposure in the study group: FB in the sputa, localized rectitude of the diaphragm, pleural thickening, pleural calcification, and the chest pain. Moreover, for all persons studied, gastrointestinal symptoms and recent hoarsening of the voice were significantly related to the number of FB in the sputa.

Adult↗
PubMed1979

Levels of asbestos air pollution in some environmental situations.

Asbestos contamination of the outside aid in Paris and suburbs has been monitored in some environmental situations, namely, "typical" urban sites removed from known sources of asbestos emissions, crossroad locations, the vicinity of a freeway, areas with buildings under construction, and areas around asbestos factories. In the same manner, measurements have been performed inside buildings of various types: those sprayed with asbestos-containing materials, those fitted with asbestos products, and control buildings. Air has been sampled by use of 0.45 micrometer pore size Millipore filters. After low-temperature ashing, ultrasonicated ashes were transferred to carbon film on 200-mesh gold grids examined under an analytic transmission electron microscope. Levels of pollution were expressed in terms of gravimetric concentrations. Inside buildings, when the air was in contact with significant amounts of asbestos-containing materials (spray, sheets), the levels were in the range 0.1--1000 10(-9) g m-3. In the vicinities of asbestos plants, the concentrations were higher: 1000--3000 10(-9) g m-3. Under other circumstances, the levels were of the same order of magnitude: 99% of the values were below 7 X 10(-9) g m-3. The Conseil Supérieur d'Hygiène Publique de France proposed a numerical ambient air quality standard of 50 X 10(-9) g m-3 inside buildings sprayed with asbestos.

Air Pollutants↗
PubMed1979

French mesothelioma register.

A total of 197 definite cases of mesothelioma (mainly of the pleura) have been reported by pathologists to the French Mesothelioma Register for the period 1965--78. A moderate linear increase in the annual incidence of mesothelioma cases since 1965 was noted. In men and women over the ages of 47 and 41 years, respectively, the annual death rate was higher in those with mesothelioma than in those of the general population. The proportions of mesothelioma patients who had experienced occupational, para-occupational, and unknown asbestos exposures were 77%, 3%, and 20% respectively. The number of cases reported to the register is obviously an underestimate of the true number of mesothelima cases in France, because such cases are not reported to the register systematically. Mesothelioma registers cannot provide information about dose-response relationships; however, with good management of the register, such relationships could be obtained, since a good assessment of dose can be accomplished by biologic monitoring.

Adult↗
PubMed1979

Human and experimental data on translocation of asbestos fibers through the respiratory system.

The translocation of fibrous dusts through the respiratory system is discussed on the basis of human and experimental data obtained with the transmission electron microscope. Comparison of the characteristics (numerical and mass concentrations, sizes, types) of asbestos fibers retained in different locations of the respiratory system in humans exposed to asbestos has shown that there is no relationship between the numerical concentrations in lung parenchyma and those in parietal pleura. Moreover, almost al fibers encountered in the pleura were ultimate, short fibrils of chrysotile. The animal data are from rats injected intrapleurally with different types of fibers (chrysotile, crocidolite and glass fibers) and sacrificed at different times. There was a progressive increase in the number and mass of fibers translocated into lung parenchyma from the pleural cavity that was particularly obvious after 90 days. After this time, the mean length of fibers, especially chrysotile, increased, indicating that more long fibers are retained in alveolar tissue than short fibers.

Animals↗
PubMed1979

Inhibition by phospholipids of haemolytic action of asbestos.

Haemolysis by asbestos fibres results from an increase in membrane permeability and not from rupture of red blood cells (RBC). The effect of chrysotile asbestos on RBC is at least partly, if not completely, attributable to lipid extraction and adsorption on to the fibres. This was suggested by the hyperbolic relationship between the haemolytic activity of chrysotile and the relative concentration of both chrysotile and RBC. Moreover, it was shown that pre-incubation of chrysotile with lipids, either as RBC membranes or with pure lipids in the form of liposomes, prevents haemolysis.

Asbestos↗
PubMed1979

Pleural effusion: laboratory tests in 300 cases.

The cause of pleural effusion was studied in 300 consecutive patients by clinical examination and laboratory tests. The three most common causes were found to be cancer 117 cases (metastatic 65, bronchogenic 34, mesothelioma 10, lymphoma 7, other 1); tuberculous infection 53; and bacterial infection 38. The cause was not found in 62 patients. Cancer diagnosis was established by cytological examination of pleural fluid (63), closed pleural biopsy (37), and open pleural biopsy (11). Tuberculosis was diagnosed by culture of pleural fluid (12), closed pleural biopsy (38), and open pleural biopsy (3). In cases of empyema 12 Gram-positive and two Gram-negative cocci and two anaerobes were identified. The various causes and the usefulness of the different investigative procedures are discussed, and the data evaluated in the light of current knowledge about mechanisms of transfer through the pleural space.

Empyema↗
PubMed1979

Asbestos fibers in laryngeal tissues. Findings in two patients with asbestosis associated with laryngeal tumors.

Significant concentrations of asbestos fibers have been found in samples of laryngeal tissue from two patients with past exposure to asbestos and associated asbestosis. In one case, there was a polyp on a vocal cord and in the other one a laryngeal carcinoma. These findings could provide an indication of a local carcinogenic effect of asbestos fibers in laryngeal tissue.

Adolescent↗
PubMed1979

[Fibre interaction with red blood cells or alveolar macrophages "in vitro" (author's transl)].

Haemolytic activities and effects on alveolar macrophages (AM) of various fibres were studied. UICC asbestos fibres and attapulgites either untreated or acid-leached were used. Amphiboles and commercial attapulgites were both cytotoxic on AM, but attapulgites and chrysotile were only haemolytic. Chrysotile fibres induced a release of B galactosidase; when acid treated these fibres were cytotoxic and less haemolytic. Acid treated amphiboles were more haemolytic than untreated.

Asbestos↗
PubMed1979

Phagocytosis of chrysotile fibers by pleural mesothelial cells in culture.

Pleural mesothelial cells (PMC) from the parietal pleura of rats were incubated in culture with UICC A chrysotile fibers. The sequence of events in phagocytosis was studied by electron microscopy: phases of attachment sequestration, and degranulation of lysosomal content into the phagocytic vacuole were observed. This demonstrates that PMC can engage in phagocytosis of chrysotile fibers.

Animals↗
PubMed1978

Partial characterisation of an elastase-like enzyme secreted by human and monkey alveolar macrophages.

An elastinolytic activity on soluble and insoluble elastin has been demonstrated in the culture medium of human and monkey alveolar macrophages. This activity is potentiated by latex particles in the medium. An enzyme resembling some other elastases was partially purified and characterised. It differs from other elastases in its affinity for elastin and a synthetic substrate, its susceptibility to various kinds of inhibitors and by its metal ion requirement.

Animals↗
PubMed1978

Biological effects of chrysotile after SO2 sorption. II. Effects on alveolar macrophages and red blood cells.

An experimental study has been carried out using different biological and biochemical in vivo and in vitro tests for assessing the toxicity of natural UICC (A) chrysotile and SO2-sorbed UICC (A) chrysotile and for detecting a possible synergistic effect. For in vivo studies, rabbits received an intratracheal injection of chrysotile fibers suspended in physiological saline (PS). The control group received only PS; all animals were sacrificed after 68 hr. The alveolar free cells were harvested by pulmonary lavage. The results have shown that chrysotile induces a decrease in the free cell population but there was no significant difference in the number of viable cells or in the nature of cells harvested between the two chrysotile groups. Enzymatic activities of the alveolar macrophages from animals injected with SO2-sorbed chrysotile showed a significant increase of the enzymes LDH and acid phosphatases. The LDH increase could be related to the affinity of the enzyme regarding some chemical forms of SO2. In vitro studies using alveolar macrophages harvested by pulmonary lavage have shown no differences between the two chrysotile groups when cell viability and enzyme release were studied. The toxic effect was due to chrysotile fibers (decrease of 38% in cell viability and increase in cellular enzyme release when compared with control). When rabbit red blood cells were used, both natural and SO2 chrysotile fibers showed the same hemolytic activity. The failure to detect high differences between the two chrysotile groups may be related to the chemical form of sorbed SO2.

Acetylglucosaminidase↗
PubMed1978

Biological effects of chrysolite after SO2 sorption. iii. effects on the biochemical components of alveolar washing.

The short-term effects of chrysotile asbestos before and after SO2 sorption are studied in the rabbit after intratracheal injection of low doses of these pollutants. Chrysotile, as well as SO2-chrysotile, induces an increase in the unsaturated fatty acid content of lung surfactant, which is similar to that observed in the respiratory distress syndrome of the newborn, and an increase in the protein level of pulmonary washings which may be explained by an increase of the permeability of the blood-air barrier. These soluble proteins can interact with the surfacant and thus decrease its tensio-active properites.

Animals↗
PubMed1978

Culture procedure of mesothelial cells from the rat parietal pleura.

Cultures were made of mesothelial cells obtained by scraping the parietal pleura of the adult rats. The growth was restricted to close polyhedric epithelial-like cells, forming a monolayer. The cellular proliferation continued until the 7th day, followed by a stationary phases. In subcultures the mesothelial cells kept their epithelial type. The cultures were stopped on the 20th day.

Animals↗