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Biomedical subjects

J Charon

Publications and source records attributed to J Charon.

30 records · Page 2Linked to original sources
PubMed1984

Secretion of a chemotactic factor for neutrophils and eosinophils by alveolar macrophages from asthmatic patients.

The studies presented in this article demonstrate the release of an IgE-dependent chemotactic factor for polymorphonuclear neutrophils (PMN) and eosinophils by alveolar macrophages (AMs) from normal subjects (n = 15) and allergic asthmatic patients (n = 15). A 60-minute incubation of normal AMs previously sensitized by 20% nonheated allergic sera with anti-human IgE antibody or the related allergen induced the release of a chemotactic activity (CA) for PMN and eosinophils in culture supernatants. When AMs were obtained from asthmatic patients, direct incubation with anti-IgE or the related allergen induced the same CA, whereas incubation with an unrelated allergen failed to produce CA (neutrophil CA after addition of anti-IgE, 22.5 +/- 3.5 cells per high power field; with related allergen, 15.8 +/- 3.6; with unrelated allergen, 0.7 +/- 1.8; p less than 0.0001). A partial characterization of the neutrophil chemotactic factor was carried out. Enzymatic treatment by trypsin or carboxypeptidase or by heating (56 degrees C for 3 hr) failed to abolish the neutrophil CA. After gel filtration the greater part of the neutrophil CA (80%) was recovered among low-molecular-weight components (300 to 1300 daltons). A preliminary deactivation of PMN by leukotriene B4 suppressed the CA of AM supernatants. These results indicate that IgE-dependent stimulation of AMs produces a neutrophil and eosinophil CA, present in a low-molecular-weight fraction possibly related to leukotrienes, and emphasizes the role of AMs in inflammatory lung processes during allergic asthma.

Adult↗
PubMed1984

Heterogeneity of human eosinophils. II. Variability of respiratory burst activity related to cell density.

Recent work has suggested that there may be heterogeneity amongst human eosinophils. In order to study this further, blood and tissue eosinophils were separated by density gradient centrifugation in discontinuous gradients of metrizamide. Blood eosinophils were obtained from 16 patients with blood eosinophil counts above 1 X 10(9)/l. Resident eosinophils were isolated from alveolar fluid in three of these patients and from pleural effusion in two others. A large proportion of the eosinophils in these patients were of light buoyant density (hypodense) and a high percentage of these showed morphological evidence of hypogranulation. Hypodense eosinophils had a reduced capacity to reduce nitroblue tetrazolium or develop chemiluminescence after stimulation with phorbol myristate acetate. It was concluded that there is structural and metabolic heterogeneity amongst blood and tissue eosinophils in patients with a variety of eosinophilic disorders.

Centrifugation, Density Gradient↗
PubMed1981

Activated macrophages in human periodontitis.

Fifteen patients, eight males and seven females, ranging from 30 to 88 years of age with advanced periodontal disease were selected for this study. Biopsies and blood samples were taken of both normal and inflamed gingival tissues, and processed for detection of nonspecific esterase and acid phosphatase activity in monocytes and macrophages. Activated macrophages, as indicated by their intense reaction to acid phosphatase and nonspecific esterase, were found in the gingival epithelium, lamina propria, perivascular tissues and in the blood vessels in human chronic periodontitis. Blood smears of monocytes showed variability of stain intensity suggesting that their activation occurred in blood vessels where they marginate and emigrate into the perivascular tissues in chronic periodontitis. They then appear as macrophages that migrate through the connective tissue, penetrate the basement membrane and continue through the epithelium. The nonspecific esterase stain identified T-cells, by a singular dot-like granule, and plasma cells by multiple granules in the cytoplasm. Lymphocytes containing multiple cytoplasmic nonspecific esterase positive granules commonly were found only in the perivascular connective tissue and may represent B-cell differentiation to plasma cells. The plasma cell predominance, the presence of T-cells and activated macrophages indicated both humoral and cell-mediated responses are operative in human chronic periodontitis.

Acid Phosphatase↗