Biomedical subjects

J M Gazave

Publications and source records attributed to J M Gazave.

At least 19 recordsLinked to original sources

PubMed1982

[Reduction of dehydroascorbic acid by thiols in presence of biocatalytic substances: polarographic study].

The chemical reduction of dehydroascorbic acid is studied in the presence of organic and vitaminic compounds. Redox properties of the compounds: ascorbic acid, dehydroascorbic acid, thiols such as glutathion, cistein, British anti-Lewisite (BAL), thiamin, riboflavin, para amino benzoic acid, biotin, 1-4 dihydronaphtoquinone and flavonoids (flavone and derived salts, quercetin rutin, 1-epicatechin and dimer) are established by direct and pulse polarography. The redox reactions are analysed by amperometry. From the results, it appears that the catalytic effect of biocatalyst of the dehydroascorbic reduction by thiols has no direct relation with the redox properties. This catalytic effect is specifically obtained with flavan-3 ol complex with antiscorbutic activities of C2 factor type.

Ascorbic Acid↗

PubMed1981

[Main part of two factors of exogenous origin contained in the blood capillary wall (author's transl)].

Besides the l-ascorbic acid (C1 factor), we put in evidence the l-epi-3',4',5',5,7-pentahydroxyflavan-3-ol (C2 factor) in the blood capillary wall. It was mainly located and found in the endothelial cell membranes. To reach that results, we used an original method using a specific polyphenoloxydase extracted from Psaliota campestris.

Animals↗

PubMed1981

[Ultrastructural alterations of the alveolar walls capillaries by injection of histamine (author's transl)].

Histamine chlorhydrate was intravenously injected to Guinea pigs (7 microgram/kg). Alterations of the alveolar walls capillaries were by electronic microscopy studied 1.5, 12 and 15 minutes after injection. It was observed a rapid dilator effect associated with an opening of the endothelial cells tight junctions, an increasing in the size and turnover of pinocytic vesicles, an enlargement and a loss of homogeneity of the basal membrane and an edema of type I pneumocytes. In the last group of animals, lesions reversibility is characterized by a beginning of closing of endothelial cells junctions and of edema resorption. These morphological findings point out the local effect of histamine on the pulmonary capillary microcirculation and show the decrease of resistance and the increase of permeability of the capillaries.

Animals↗

PubMed1980

[Part of ascorbic acid in the maintenance of the blood capillary wall. New data (author's transl)].

The part of ascorbic acid in the blood capillary wall is shown by deficiency experiment. The pictures obtained by electron microscopy show that, non only is the ascorbic acid needed for the structure integrity of the basement membrane, but also for the permeability of the capillary wall, which when this compound is lacking becomes too important.

Animals↗

PubMed1978

Original method of showing some constitutive elements of the capillary wall.

The ascorbic acid and the 1-epi-3', 4', 5', 5, 7-pentahydroxy-flavan-3-ol have been located in the blood capillary wall by an histochemical method for electron microscopy. The method consists in an intra-arterial administration of vegetal oxydases specific of the compound to put in evidence. Those oxydases fix themselves on their effectors, and the addition of osmium and lead salts gives co-precipitates opaque to electrons.

Animals↗

PubMed1975