Search PubMed⌕ Search

Biomedical subjects

J Bignon

Publications and source records attributed to J Bignon.

At least 145 records · Page 8Linked to original sources
PubMed1982

[Non-ventilatory functions of the cells of the respiratory system].

The physiology of the respiratory system was limited until recently to study of the structures subjected to simple physical laws and involved in gas exchanges only. Today, the airways and lung itself are conceived as complex living structures adapted to defence against exogenous, microbiological, organic and inorganic substances which reach the respiratory epithelium, contained in the 10 to 12 m3 of air entering and leaving the lungs daily. In addition, the considerable surface area represented by the endothelium of the pulmonary circulation is a site of synthesis and elimination, the implications of which are increasingly important in the area of the metabolism of endogenous substances: prostaglandins, vasomotor substances and the bioconversion of drugs and toxic agents. This is an increasingly large area of research and investigation, the clinical applications of which appear to be more and more frequent and important.

Arachidonic Acids↗
PubMed1981

Rat pleural mesothelial cells in culture.

A culture system has been developed for long-term maintenance of rat pleural mesothelial cells. Mesothelial cells were isolated from the parietal pleura of rats and cultured in NCTC 109 medium supplemented with 10% fetal bovine serum. The cell explants attached to the dish and formed a confluent monolayer of polygonal cells within 10 to 15 days. Subcultures were made in the same medium. The mean population doubling time was approximately 30 hr. The ultrastructure of the mesothelial cells in culture was studied by light and electron microscopy and was compared with that of cells obtained from sub-mesothelial components.

Animals↗
PubMed1981

In vitro reactivity of alveolar macrophages and red blood cells with asbestos fibres treated with oxalic acid, sulfur dioxide and benzo-3,4-pyrene.

The effects of 3 UICC asbestos fibres (A chrysotile, crocidolite, amosite) were observed in vitro on red blood cells (RBC) and alveolar macrophages (AM). THe reactivity of the fibres after leaching with 0.1 N oxalic acid or adsorption of SO2 or benzo-3,4-pyrene (BP) was studied. The haemolytic activity of crocidolite and amosite was very low. A cytotoxic effect on AM occurred when the fibres were present in high concentration (100 microgram/ml), this was characterized by a release of both cytoplasmic (LDH) and lysosomal (beta-galactosidase) enzymes. The leached fibres were more haemolytic than the unleached ones, and more beta-galactosidase (beta-Gal) than lactic dehydrogenase (LDH) was released from the AM. In contrast to the amphiboles, chrysotile fibres were highly haemolytic and induced a selective release of beta-Gal from AM. Leached fibres were less haemolytic and were cytotoxic for AM (both enzymes were released). Their in vitro reactivity was similar to that observed with quartz. The results showed that SO2 changed the reactivity very little. BP sorption on acid-leached chrysotile decreased the LDH release from AM. The difference in the in vitro reactivity related to the chemical state of asbestos fibres might explain the difference in their in vivo reactivity (latency, degree of fibrosis). This point is discussed.

Animals↗
PubMed1981

Mesotheliomas in rats following inoculation with acid-leached chrysotile asbestos and other mineral fibres.

The carcinogenicity of untreated UICC chrysotile A, of acid (oxalic and hydrochloric)-leached UICC chrysotile A, of crocidolite and of JM 104 glass fibres has been studied by intrapleural injection into rats. This experiment, carried out on 304 animals, demonstrated that when more than 80% of the Mg had been leached from chrysotile fibres by either hydrochloric or oxalic acid, the proportion of pleural mesotheliomas was either nil or dramatically lower than that obtained with untreated chrysotile. The carcinogenic effect of crocidolite was higher than that of 43.7% oxalic acid-leached chrysotile. The proportion of mesotheliomas observed in animals injected with JM 104 glass fibres was similar to that in animals injected with fibres from which 63.8% had been leached with oxalic acid. These results indicate that with regard to the induction of pleural carcinogenicity by chrysotile fibres, not only size characteristics but also parameters such as chemical composition and physiochemical properties must intervene.

Animals↗
PubMed1981

Zeolite bodies in human lungs from Turkey.

It is thought that the extremely high occurrence of malignant pleural mesothelioma in the two Turkish villages of Karain and Tusköy could be related to environmental zeolite fibers. Mineral fibers were assessed in lung samples from two cases of malignant pleural mesothelioma in Tusköy, using the light microscope and the analytical transmission electron microscope. Zeolite (erionite) fibers and ferruginous bodies, formed around zeolite fibers (zeolite bodies), were frequently encountered in these samples. Under the light microscope, zeolite bodies were morphologically identical to typical asbestos bodies. To document the zeolite exposure in this area of Turkey, it is suggested that a biologic monitoring study be performed in villages in which mesotheliomas occur and in control villages, by testing for the presence of zeolite bodies in sputum.

Aluminum Silicates↗
PubMed1981

[Etiological and histological study of 448 cases of lung cancer (author's transl)].

The study of this series of hospitalized patients extended over a period of 8 years, and the number of cases was estimated to be 1/8 of the total lung cancer population seen in the area serviced by the hospital. Distribution according to sex was in the ratio 18.6/1 and the mean age (60 to 62.8 years) was identical whatever the sex, smoking habits, presence or a absence of exposure to asbestos, and the histological type. The epidermoid type was more frequent, both in men (77.6 p. cent) and women (39.1 p. cent). A significant relationship with smoking was observed in the epidermoid form but not with adenocarcinomas. In men who smoked there were 78.6 p. cent of epidermoids against 53.8 p. cent in women, in whom the percentage of undifferentiated types (15.3 p. cent) exceeded that of the men (5.7 p. cent). In nonsmokers, adenocarcinomas represented 70 p. cent in women against 37.5 p. cent in men. In 9 p. cent of the cancers the patient had been exposed to asbestos during their occupation, the degree of exposure being low or moderate in 78 p. cent. The cancers were more frequently proximal (73 compared with 54.2 p. cent), bilateral (8 compared with 3.4 p. cent), derived from the inferior lobe (superior to inferior lobe ratio: 1.2 to 2.75), more often undifferentiated (20 against 4.2 p. cent), and less frequently of the epidermoid type (65 compared with 80.1 p. cent). The histological type is discussed as a function of the methodology of the histological diagnosis, and of the etiological factors, particular smoking and exposure to asbestos.

Adenocarcinoma↗
PubMed1981

[Diagnostic value of fiberoptic bronchoscopy in pneumopathies in immunodeficient adults: a report on 59 examinations (author's transl)].

Fifty-nine fiberoptic examinations with endobronchial sampling, brushings, distal bronchial biopsy, and alveolar lavage were conducted during the course of recent pneumopathies in immunodeficient adults with malignant hemopathies (41 cases), solid tumors (7 cases), and other affections (11 cases). Diagnosis was established by fiberoptic bronchoscopy in 4 cases with specific locations of hemopathy or cancer, after bronchial biopsy, in 5 cases of mycoses, after bronchial biopsy, aspiration and/or alveolar lavage, in 4 patients with bacterial pneumonia after bronchial aspiration, and in 1 case of pneumocystosis, after distal biopsy. Diagnosis was not confirmed in the other cases. Mortality (50 p. cent) was similar in the diagnosed group and the group without confirmation of diagnosis. No significant complications due to the examination were observed, except for worsening of the respiratory condition in 7 patients with hypoxemia. The role of fiberoptic bronchoscopy in causing these alterations cannot be excluded. Fiberoptic bronchoscopy appears to be a safe examination except in patients with hypoxemia (PaO2 less than or equal to 50 mmHg). Distal biopsy appeared to be of less value than bronchial biopsy in these patients, as there was a positive correlation between the results of the latter examination and the macroscopic lesions observed in all cases.

Adult↗
PubMed1980

[Respiratory allergy to house dust. A comparison between clinical reactions and the results of some diagnostic tests. 54 cases (author's transl)].

Fifty-four cases of respiratory allergy to house dust were studied by observing clinical reactions and, simultaneously, the results of skin tests, respiratory function tests, radio-allergo-sorbent test (RAST) and human basophil degranulation test (HBDT). The standard skin tests matched clinical reactions and correlated better with the results of HBDT (89.5%) than with those of RAST (50%). This would suggest that HBDT is a more reliable test to explore immediate hypersensitivity to heterogenous allergens.

Adolescent↗