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J Desbordes

Publications and source records attributed to J Desbordes.

At least 37 records · Page 2Linked to original sources

[An unusual case of talco-asbestosis].

The authors present an unusual case of asbestosis. The latter had very diffuse macrophagic and giant cell granulomatous lesions. The morphological findings and the history enabled one to relate the appearance observed to the conjoined handling of asbestos and talc. A primary adenocarcinoma developed on these lesions.

Asbestosis↗

[Asparagine metabolism in mycobacteria. II. -- Asparagine hydrolysis and aspartohydroxamic acid formation and hydrolysis catalysed by M. fortuitum, M. phlei and BCG asparaginases (author's transl)].

Crude extracts of BCG, M. fortuitum and M. phlei, hydrolyse asparagine (I) and L-beta-asparthohydroxamic acid (III), and catalyse the synthesis of aspartohydroxamic acid from asparagine and hydroxylamine (II). The ratio between these enzymatic activities (I:II and I:III) presents a certain stability during the different steps of purification of these mycobacteria asparaginases. In particular, M. fortuitum asparaginase has been purified 90 to 130-fold, with recovery of approximately 10%. Only the fractions of supernatants which have an asparaginase activity catalyse the formation of aspartohydroxamate from asparagine and hydroxylamine. Some differences between the asparaginases of these strains are described. Particularaly, in comparison to reaction I, their abilities to catalyse reactions II and III vary noticeably from one asparaginase to an other. The asparaginase of BCG catalyses very slightly in the reactions II and III and is more specific of L-asparagine hydrolysis than are the asparaginases of M. fortuitum and of M. phlei. Furthermore, in the case of M. phlei, p-chloromercuribenzoate (pCMB) inhibits very stronly the reactions I and III and slightly reaction II, whereas conversely, for M. fortuitum, pCMB does not inhibit reactions I and III but strongly inhibits reaction II. In the case of BCG, these three reactions are not inhibited by pCMB. Moreover, the asparaginases from these strains are more or less sensitive to the ionic strength of the buffer used.

Asparaginase↗

[Polyol dehydrogenases in mycobacteria (author's transl)].

Contrary to the the tubercle bacilli (H37Ra, BCG), Mycobacterium phlei, grown on Sauton medium, formed the NAD+ dependent dehydrogenases that catalyse the oxidation of ribitol, sorbitol and mannitol. These enzymes were separated by chromatography on DEAE-cellulose and Sephadex G-200. In the present work we have principally studied the ribitol dehydrogenase. All the experiments for induction of the ribitol dehydrogenase in H37Ra or BCG were negative; whereas after the adaptation of M. phlei to ribitol, the specific activity of this enzyme increased in the supernatants more than 100 per cent. The ribitol dehydrogenase of M. phlei reduced NAD+ not only in the presence of ribitol but also (though to a lesser extent) in the presence of erythritol and glycerol. Other properties studied concerning this enzyme and the reaction it catalyses were: pH dependence, equilibrium constant, Km and sensitivity towards the inhibitors of the thiol groups.

Erythritol↗