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P Huet

Publications and source records attributed to P Huet.

27 records · Page 2Linked to original sources
PubMed1993

Spectrophotometric assay of superoxide dismutase activity based on the activated autoxidation of a tetracyclic catechol.

A new spectrophotometric assay of superoxide dismutase (SOD) activity is described. The assay is based on the SOD-mediated increase in the rate of autoxidation of 5,6,6a,11b-tetrahydro-3,9,10-trihydroxybenzo[c]fluorene (BXT-01050) in aqueous alkaline solution. This autoxidation yields a chromophore with a maximal absorbance wavelength of 525 nm. The optimized assay of SOD activity is performed at pH 8.8, 37 degrees C, in 50 mM air-saturated 2-amino-2-methyl-1,3- propanediol buffer containing 3 mM boric acid and 0.1 mM diethylenetriaminepentaacetic acid. The kinetic measurement of 525-nm absorbance is performed for 1 min upon addition of BXT-01050. BXT-01050 is stabilized in stock solution acidified at pH 1.5. The SOD activity is determined from the Vs/Vc ratio of the autoxidation rates measured in the presence (Vs) and in the absence (Vc) of sample. One SOD activity unit (U-525) has been defined as the activity that doubles the autoxidation background (Vs/Vc = 2). The equation that fits the standard curve is the same with all studied SODs. Another reagent, 1,4,6-trimethyl-2-vinylpyridinium trifluoromethanesulfonate, directly eliminates interference due to sample mercaptans such as glutathione by means of a very fast alkylation reaction. A fast and reproducible measurement of SOD activity requires only a single determination per sample. At pH 8.8, an optimal assay sensitivity is achieved without strongly affecting the activity of known SODs such as Cu/Zn-, Mn-, or Fe-SOD.

Animals↗
PubMed1993

[Evaluation of velopharyngeal function using an aerophonoscope before and after surgery for snoring].

Following surgery for snoring, regardless of the technique used, velopharyngeal insufficiency remains an infrequent but disabling complication. In an attempt to assess the risk of velopharyngeal insufficiency, we used a new, simple, rapid, and noninvasive method of evaluating palatal function, the aerophonoscope. Pre and postoperative aerophonoscopic studies were carried out in 25 chronic snores undergoing a single step uvulopalatoplasty with a laser under local anesthesia. The aerophonoscope revealed signs of palatal dysfunction in 2 patients (8%) preceding surgery and confirmed the absence of palatal dysfunction in all patients following our technique of uvulopalatoplasty. We also present the aerophonoscopic findings in 3 patients with nasopharyngeal stenosis and 2 patients with velopharyngeal insufficiency following surgery for snoring.

Humans↗
PubMed1993

[Segmental neurofibromatosis].

Segmental neurofibromatosis is a rare form of the disease characterized by the unilateral location of cutaneous neurofibromas and café au lait spots along one or several dermatomes. It corresponds to the fifth type in Riccardi's classification. We report the 83rd case of segmental neurofibromatosis discovered by chance in an 83-year old woman presenting with isolated cutaneous neurofibromas situated on the right T10-L1 dermatomes. Type five neurofibromatosis is divided into four subgroups according to the uni- or bilateral site of the lesions, the presence or absence of a family history and the association, or lack of, with deep regional or systemic lesions. It is usually not hereditary, but due to a post-zygotic somatic mutation in the primary neural crest. The disease has a favourable prognosis: no case of evolution towards generalized neurofibromatosis has ever been reported.

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