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Biomedical subjects

J Bignon

Publications and source records attributed to J Bignon.

At least 199 records · Page 11Linked to original sources
PubMed1978

[Use of the transmission electron microscope in the analysis of wine contamination by asbestos].

A method for assessing chrysotile asbestos fibers in wines is described. Particles are isolated from wines samples by means of microfiltration through Nuclepore membrane. Retained particles are entrapped in a carbon layer which is observed under a transmission electron microscope fitted with an energy dispersive spectrometer. Chrysotile fibers identification is based on the determination of three characteristics- namely, morphology, elemental composition and crystal structure. Fibers are counted and measured (length and diameter) on an aliquot of the preparation area: numerical concentrations and their statistical significance are calculated. Several factors affect the accuracy and precision of this method. The feasibility for numerous laboratories to use this method is discussed.

Asbestos↗
PubMed1977

Ultrastructural examination of broncho-alveolar lavage for diagnosis of pulmonary histiocytosis X: Preliminary report on 4 cases.

Fibreoptic broncho-alveolar lavage was used in four patients; the diagnosis of histiocytosis X had been established by lung biopsy in three and was suggested on clinical grounds in the remaining patient. Characteristic cells with an ultrastructural cytoplasmic marker (X body) were found in the washes of all four patients. In the patient without biopsy confirmation, the findings in the broncho-aleolar washes supplied the corroborating evidence for the diagnosis. From this preliminary study the technique seems able to provide a diagnosis in pulmonary histiocytosis X without the need for an open lung biopsy.

Adolescent↗
PubMed1976

Immunoelectron microscopic and immunochemical demonstrations of serum proteins in the alveolar lining material of the rat lung.

By means of antibodies labeled with horseradish peroxidase, autologous albumin and IgG were visualized in electron microscopy on the alveolar epithelial surface of the rat lung, as a continuous cell coat, as free granular deposits, or associated with tubular myelin figures. These 2 proteins were detected by immunochemistry in alveolar washing. After ultracentrifugation of alveolar washing, they were still found in the phospholipid-rich precipitate fraction by immunization of rabbits and by immunoelectron microscopy. Thus, albumin and IgG appeared as normal alveolar components in the rat lung; fibrinogen was not found under normal conditions.

Animals↗
PubMed1976

Plasma protein immunocytochemistry and polysaccharide cytochemistry at the surface of alveolar and endothelial cells in the rat lung.

Ultrastructural immunocytochemistry of plasma proteins and cytochemistry of polysaccharides with ruthenium red and concanavalin A were combined with different types of fixation with or without prior vascular or airway washing, to study the surface of capillary endothelial and alveolar epithelial cells of the blood-air barrier in the rat lung. The endothelial and epithelial cell surface layers were found to have two components: a moveable part belonging to the cellular microenvironement made of plasma proteins and a deeper glucidic or anionic fixed part bound to the plasma membranes (cell coat).

Animals↗
PubMed1975

Ultrastructural immunoperoxidase demonstration of autologous albumin in the alveolar capillary membrane and in the alveolar lining material in normal rats.

The location of autologous serum albumin within the alveolar-capillary membrane was studied in the rat under physiological conditions using antialbumin antibodies labeled with peroxidase. Albumin was detected in the lung interstitium, and in numerous pinocytic vesicles within endothelial cells and type I alveolar epithelial cells. The immunoreaction was also positive at the level of plasmalemmal membranes of both cell types and in the alveolar lining material.

Animals↗
PubMed1975

[Phenotype Pi and alpha 1 antitrypsin deficiency in types A and B chronic obstructive bronchopneumopathies].

The authors studied 79 patients with chronic obstructive lung disease. (COLD) (FEV1/VC less than 70%). Patients with chronic asthma were excluded from the series. These patients with COLD were divided up into 2 groups, depending on radiological and clinical criteria: (1) Type A, primary emphysema, 24 patients; (2) Type B, chronic bronchitis, 49 patients. 6 patients of type X (intermediate type) were excluded. Their respiratory function tests were studied together with clinical and radiological findings and blood gases. Furthermore, were studied in each patient, the antitrypsic activity and the serum concentrations of alpha-1-antitrypsin and phenotype Pi. Group A were, on average, more obstructive than group B. The ratio FEV1/VC was 31% +/- 7% in group A, against 46% +/- 13% in group B. The serum antitrypsin activity and the serum concentration in alpha-1-AT were on average close to normal in both groups. However, group A was divided up into two populations: a small population with a low concentration of alpha-1-AT, and a large population with normal alpha-1-AT. A study of the incidence of various phenotypes in groups A and B showed a significantly higher frequency of phenotype ZZ in group A (12.5%) than in group B (10%). All ZZ subjects were of clinical type A. There was no significant difference in the incidence of other phenotypes encountered. Serum alpha-1-antitrypsin concentration was very low in 3 ZZ patients. One case with phenotype SZ and one MM showed intermediate levels. The authors emphasize the low percentage of cases of pulmonary emphysema which may be explained by an alpha-1-antitrypsin deficiency. Nevertheless, this preliminary report should be completed by a study of a larger sample of patients with COLD with control of the phenotype.

Alleles↗
PubMed1975

[The small airways obstruction: an assay of structure-function correlation].

A review is made of the structural lesions responsible of the small airways obstruction: stenosis of the peripheral membranous bronchioles, either segmental stenosis or diffuse narrowing; loss of bronchioles consecutive to the inflammatory destruction of their walls; mucus plugs; fine or metabolic modifications of the distal bronchiolar epithelium. It is probable that these two latter lesions,--mucus plugs and lesions of the bronchiolar epithelium--, are reversible. Nevertheless, we don't know presently what are among these various bronchiolar lesions those responsibles for the alteration of the functional tests used in the study of early obstruction of the small airways.

Bronchi↗
PubMed1975

Topographic distribution of asbestos fibres in human lung in relation to occupational and non-occupational exposure.

A topographic study of asbestos fibre content of lung and pleura of diversely exposed cases has been carried out. For heavily exposed cases with lung fibrosis, this study has stressed the distinctive behaviour of the peripheral lower lobe in the retention of asbestos fibres in the lung. In these areas were found the smallest asbestos concentrations but the largest fibres. For cases without lung fibrosis, the results clearly demonstrated an accumulation of asbestos fibres, especially of chrysotile type, in peripheral areas. These findings are to be related to the incidence of pleural mesothelioma associated with moderate or low exposure. The small variation of fibre concentration in the pleural plaques of diversely exposed subjects is pointed out.

Adult↗
PubMed1975

[Mathematical study of size distribution of alveolar mononuclear cells (CMA) in man].

The mathematical study using the Wicksell transformation of the size distribution of the mononuclear alveolar cells has shown two different populations among the alveolar macrophages obtained from 4 adult men. These two types of cells could be also found out and described by electron microscopy. The large cells (14 microns in diameter) looked like the "alveolar macrophage ", with many phagolysosomes. The small cells (7 microns in diameter), less numerous (1/3 of the whole population) resembled monocytes. These data in man are compared to those found in rabbits and the role ot two kinds of cells is discussed.

Animals↗