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F Lépine

Publications and source records attributed to F Lépine.

7 recordsLinked to original sources
PubMed1991

Carboxylation of o-cresol by an anaerobic consortium under methanogenic conditions.

The metabolism of o-cresol under methanogenic conditions by an anaerobic consortium known to carboxylate phenol to benzoate was investigated. After incubation with the consortium at 29 degrees C for 59 days, o-cresol was transformed to 3-methylbenzoic acid, which was not further metabolized by the consortium. Proteose peptone in the culture medium was essential for the transformation of o-cresol. In addition, a transient compound detected in the culture was identified as 4-hydroxy-3-methylbenzoic acid. o-Cresol-6d was transformed by the consortium to deuterated hydroxy-methylbenzoic acid and deuterated methylbenzoic acid. These results demonstrate that o-cresol is carboxylated in the para position relative to the phenolic hydroxyl group and dehydroxylated by the anaerobic consortium.

Bacteria, Anaerobic↗
PubMed1990

Degradation pathways of PCB upon gamma irradiation.

In order to understand the modifications of the chromatographic profile of Aroclor 1260 upon gamma irradiation, a total of 14 pure polychlorinated biphenyl (PCB) congeners were separately irradiated in solution. Dechlorination was observed, and the generated products were investigated by gas chromatography and mass spectrometry. Degradation proceeds more rapidly in methanol/water mixture than in petroleum ether, but the relative amount of ortho-dechlorinated congeners formed upon irradiation was smaller in the former solvent. Ortho chlorines are preferentially lost in petroleum ether except when they are involved in a 2.5 (or 3.6) substitution pattern, in which case para dechlorination becomes predominant. The precursors of some toxicologically important congeners such as congeners 77, 118, 167, and 189 have been identified. These data are useful to rationalize the modifications of the chromatographic profile of PCB complex mixture upon gamma irradiation.

Aroclors↗
PubMed1990

[Post-varicella anetoderma. 3 cases].

We report three cases of typical macular atrophy which appeared during, or was noticed shortly after varicella. The three patients were children. These cases were particular in that anetoderma lesions occurred independently of the scarring varicella lesions and followed a prolonged course of their own afterwards. We were unable to classify these cases in the primary or secondary type of macular atrophy. The various dermatoses associated with macular atrophy and the numerous physiopathological hypotheses put forward concerning this entity are enumerated.

Atrophy↗
PubMed1989

Catalase activity measurement with the disk flotation method.

Activity measurements of catalase are usually performed with a spectrophotometric method by monitoring the decrease of H2O2 at 240 nm. A different method presented here uses an instrument named Catalase-meter and yields flotation time data which are expressed in tenth of seconds. For the first time, solutions of catalase of different concentrations were tested simultaneously with the two methods, and the Catalase-meter's flotation data were submitted to correlation with international units calculated from spectrophotometric data. The corresponding calibration curve correlates flotation time data to international units. The r2 values thus obtained for the two calibration curves were 0.960 and 0.929, for a range of activity varying from 9.3 to 144.5 international units/ml.

Animals↗