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J Biguet

Publications and source records attributed to J Biguet.

At least 37 records · Page 2Linked to original sources

[Study of the Sporothrix schenkii (yeast forms) extract. Electrophoretic and immunoelectrophoretic analyses: characterization of enzymatic activities].

An extract from living yeast forms of S. schenckii was prepared. The yeasts originated from a shake culture in B.H.I. broth (Difco) incubated for 3 days at 35 degrees C in darkness; they were harvested, washed and disrupted with glass beads in a model MSK Braun mechanical cell homogenizer; a freezing-thawing was added to improve the extract. After electrophoretic separation in agarose gel, the extract's components were characterized by their enzymic activity; with this technique, 30 bands were revealed. These enzymic activities were also investigated on the antigenic fractions of the extract revealed by a rabbit hyperimmunserum: 16 among 22 immunoprecipitates are identified by their catalytic properties. Study of the earliest precipitating antibodies (appearing-order and enzymic caracterization) in rabbits just immunized completes this work. How to ameliorate the quality of the extract by culture and extraction conditions is also specified.

Cell-Free System↗

[Photoinhibition of chlamydosporulation of Candida albicans].

Candida albicans produced chlamydospores after 24 h in the dark at 27 degrees C, but the process was inhibited under adequate irradiation of light. The in vivo absorption spectra showed a main peak at 414 nm, and less important peaks at 430, 446, 477, 519, 549 and 560 nm. No bands were detected beyond 600 nm. A total inhibition of chlamydosporulation occurred at 414 nm (monochromatic light) for an initial energy of 2,000 ergs cm-2 s-1. A 4,000 ergs cm-2 s-1 irradiation energy was necessary to observe a marked inhibition at 460, 500 and 530 nm (les chlamydospores and/or immaturity); this energy must be raised to 300,000 ergs cm-2 s-1 to observe a similar effect at 575 and 630 nm. Biological activity spectra were in full concordance with absorption spectra at 414 nm; no interpretation of absorption band at 460 nm is given, but total or partial inhibition could be explained by modulation of protoporphyrin activity.

Candida albicans↗

[Comparative enzymatic study of two strains of Aspergillus fumigatus and of A. fischeri of sapropytic origin or isolated from human or animal lesions: practical diagnostic applications].

14 enzymatic activities (3 dehydrogenases and 11 hydrolases) were systematically investigated in the extracts of 2 strains of Aspergillus fischeri and 14 strains of A. fumigatus (8 isolated from human or animal lesions named 'pathogenic' strains and 6 strains of saprophytic origin). The enzymic composition of A. fumigatus appeared to be very different from one strain to another but no relationships could be established between enzymic differences and origin of the strains. In addition, the immunoelectrophoretic analysis of these antigenic extracts using rabbits immunsera and sera of patients with pulmonary asperigllosis was performed. The type II chymotrypsic activity, corresponding to C arc, was shown more frequently and gave stronger reaction when antigenic extracts from pathogenic strains were allowed to react with sera of patients. Moreover, when sera of patients revealed a same enzymic activity in a saprophytic strain and a pathogenic strain, the number of precipitin lines was significantly larger with the latter one. Accordingly, antigenic extracts used for precipitin tests had to be preferably prepared from pathogenic strains and tested, for value, against sera of patients with pulmonary aspergillosis.

Alkaline Phosphatase↗

Sulphitolysis in keratinolysi. Biochemical proof.

The presence of S-sulphocysteine in filtrates of the dermatophyte Keratinomyces ajelloi growing on human hair in a culture medium buffered by pH 7-4 by phosphates was demonstrated by means of ion exchange chromatography techniques. S-sulphocysteine being destroyed during acidic hydrolysis was identified after enzymic hyrolysis of dialyzed and lyophilized filtrates. This result indicates that sulphitolysis occurs during kerationlysis performed by K. ajelloi. As thiosulphuric esters were shown present in hair perforations made by Microsporum gypseum, we think sulphitolysis is a common mechanism developed by dermatophytes to attack keratin.

Culture Media↗

[Growth and sexual reproduction of the dermatophyte Arthroderma vanbreuseghemii Takashio (Trichophyton mentagrophytes (Robin blanchard) on a synthetic medium].

A synthetic medium without agar is proposed for the growth and the sexual reprpduction of the dermatophyte Arthroderma vanbreuseghemii (Trichophyton mentagrophytes). The determinations of mycelium dry weight showed that this species grew poorly with only one amino-acid as nitrogen source. A. vanbreuseghemii grew weakly on a mixture of glutamic and aspartic acid and serin. A small amount of aromatic amino-acids added to this mixture, increased the growth rate comparable to that obtained on peptone. The sexual reproduction was induced on synthetic medium with a propicious balance between carbon and nitrogen sources. Addition of 0.5 or 1g/1 of glucose to 50 mg N/1 supplied by the amino-acids mixture (including the aromatics) gave the optimal ratio. Using these conditions, many cleistothecia was produced by crossing two semi-compatible strains.

Amino Acids↗

[The mycelial wall of Trichophyton mentagrophytes; ultrastructural study of its constitutive layers following the use of a method to demonstrate polysaccharides].

The ultrastructure of T. mentagrophytes hyphal walls was studied after the use of a cytochemical reaction for polysaccharides. The sections showed a wall composed of 3 layers viz: an external, poorly reactive one with a microfibrillary structure; a medium, fairly reactive one, with a periodic structure and an internal, intensivly stained layer, not observed in old cells. Other observations suggested that the septal medium layer should be differentiated from those cited above. The results are compared with previous data and a synthetic scheme of the Trichophyton mentagrophytes hyphal wall is proposed.

Cell Wall↗