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Bedia C.,French Institute of Health and Medical Research | Bedia C.,University Paul Sabatier | Camacho L.,CSIC - Institute of Advanced Chemistry of Catalonia | Abad J.L.,CSIC - Institute of Advanced Chemistry of Catalonia | And 4 more authors.
Journal of Lipid Research | Year: 2010

Acid ceramidase (aCDase) is one of several enzymes responsible for ceramide degradation within mammalian cells. As such, aCDase regulates the intracellular levels of the bioactive lipid ceramide. An inherited deficiency of aCDase activity results in Farber disease (FD), also called lipogranulomatosis, which is characterized by ceramide accumulation in the tissues of patients. Diagnosis of FD is confirmed by demonstration of a deficient aCDase activity and the subsequent storage of ceramide. Existing methods include extremely complex assays, many of them using radiolabeled compounds. Therefore, the aCDase assay and the in vitro enzymatic diagnosis of FD are still performed in only a very limited number of specialized laboratories. Here, the new fluorogenic substrate Rbm14-12 was synthesized and characterized as a new tool to determine aCDase activity. The resulting optimized assay was performed in 96-well plates, and different fibroblast and lymphoid cell lines derived from FD patients and controls were tested to measure aCDase activity. As a result, the activity in cells of FD patients was found to be very low or even null. This new fluorogenic method offers a very easy and rapid way for specific and accurate determination of aCDase activity and, consequently, for diagnosis of FD. Copyright © 2010 by the American Society for Biochemistry and Molecular Biology, Inc. Source

Formosa C.,French National Center for Scientific Research | Formosa C.,Toulouse 1 University Capitole | Grare M.,Institute Federatif Of Biologie | Duval R.E.,University of Lorraine | And 2 more authors.
Nanomedicine: Nanotechnology, Biology, and Medicine | Year: 2012

Studying living bacteria at the nanoscale in their native liquid environment opens an unexplored landscape. We focus on Pseudomonas aeruginosa and demonstrate how the cell wall is biophysically affected at the nanoscale by two reference antibiotics (ticarcillin and tobramycin). The elasticity of the cells drops dramatically after treatment (from 263 ± 70 kPa to 50 ± 18 and 24 ± 4 kPa, respectively on ticarcillin- and tobramycin-treated bacteria) and major micro- and nano-morphological modifications are observed (the surface roughness of native, ticarcillin- and tobramycin-treated bacteria are respectively 2.5, 0.8, and 4.4 nm for a surface area of 40,000 nm2). Thus the nanoscale approach in liquid is valid and can be extended. From the Clinical Editor: Pseudomonas aeruginosa cell wall was demonstrated to be biophysically affected at the nanoscale by two reference antibiotics, ticarcillin, and tobramycin, with the elasticity dropping dramatically after treatment. © 2012 Elsevier Inc. Source

Izopet J.,Institute Federatif Of Biologie
Revue Francophone des Laboratoires | Year: 2010

Hepatitis E virus (HEV) is an agent responsible for waterborne acute hepatitis in tropical and subtropical areas. Epidemiological and molecular data indicate zoonotic transmission of HEV in industrialized countries. HEV infections can lead to fulminant hepatitis in pregnant women and patients with chronic liver diseases. The virus can persist in immunocompromised patients and lead to chronic hepatitis and cirrhosis. Among mammalian strains, genotypes 1 and 2 HEV are found only in humans. By contrast, genotype 3 and 4 have been characterized both in humans and several animal species (pigs, wild-boars and deers). Avian strains have also been described but they are not transmissible to humans. Further studies are needed to improve our knowledge on the size of animal reservoir and molecular and cellular determinants of viral tropism.. © 2010 - Elsevier Masson SAS - Tous droits réservés. Source

Robert J.,University Pierre and Marie Curie | Tristan A.,University of Lyon | Cavalie L.,Institute Federatif Of Biologie | Decousser J.-W.,Bacteriologie Hygiene | And 3 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2011

The epidemiology of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) differs from country to country. We assess the features of the ST80 European clone, which is the most prevalent PVL-positive CA-MRSA clone in Europe, and the TSST-1 ST5 clone that was recently described in France. In 2008, all MRSA strains susceptible to fluoroquinolones and gentamicin and resistant to fusidic acid that were isolated in 104 French laboratories were characterized using agr alleles, spa typing, and the staphylococcal cassette chromosome mec element and PCR profiling of 21 toxin genes. Three phenotypes were defined: (i) kanamycin resistant, associated with the ST80 clone; (ii) kanamycin and tobramycin resistant, associated with the ST5 clone; and (iii) aminoglycoside susceptible, which was less frequently associated with the ST5 clone. Among the 7,253 MRSA strains isolated, 91 (1.3%) were ST80 CA-MRSA (89 phenotype 1) and 190 (2.6%) were ST5 CA-MRSA (146 phenotype 2, 42 phenotype 3). Compared to the latter, ST80 CA-MRSAs were more likely to be community acquired (80% versus 46%) and found in young patients (median age, 26.0 years versus 49.5 years) with deep cutaneous infections (48% versus 6%). They were less likely to be tetracycline susceptible (22% versus 85%) and to be isolated from respiratory infections (6% versus 27%). The TSST-1 ST5 clone has rapidly emerged in France and has become even more prevalent than the ST80 European clone, whose prevalence has remained stable. The epidemiological and clinical patterns of the two clones differ drastically. Given the low prevalence of both among all staphylococcal infections, no modification of antibiotic recommendations is required yet. Copyright © 2011, American Society for Microbiology. All Rights Reserved. Source

Feigerlova E.,Toulouse University Hospital Center | Diene G.,Toulouse University Hospital Center | Oliver I.,Toulouse University Hospital Center | Gennero I.,Institute Federatif Of Biologie | And 6 more authors.
Journal of Clinical Endocrinology and Metabolism | Year: 2010

Background: Children with Prader-Willi syndrome (PWS) are routinely treated with GH and have a response comparable with that observed in children with GH deficiency (GHD). Objective: The objective of the study was to compare changes in serum IGF-I, IGF binding protein 3 (IGFBP-3), IGF-I to IGFBP-3 molar ratio, and growth velocity during the first 2 yr of GH therapy in PWS and GHD children. Subjects and Methods: Thirty-three children with PWS (14 boys, 4.9 ± 3.8 yr) and 591 with GHD (351 boys, 9.6 ± 3.6 yr), all naive to GH treatment, were included in this study. Serum IGF-I and IGFBP-3 were measured at 0, 6, 12, and 24 months of GH therapy. The mean initial dose of GH was 0.9 and 1 mg/m2·d in the PWS and GHD groups, respectively. Results: Mean ± SD IGF-I SDscore (SDS) and IGFBP-3 SDS were significantly higher in PWS compared with GHD. The IGF-I to IGFBP-3 molar ratio was significantly lower at baseline and subsequently not different. Despite significantly lower GH doses in PWS children at 6, 12, and 24 months (P = 0.021, P = 0.021, P = 0.001), IGF-I reached 2.8 ± 1.2 SDS at 24 months (72% of values > 2 SDS), and remained at 0.7 ± 1.6 SDS in GHD children (17% of values > 2 SDS). IGFBP-3 did not exceed 2 SDS in either group. There was no significant change in the IGF-I to IGFBP-3 molar ratio. Conclusions: IGF-I SDS increases to a greater extent in PWS than GHD. Bioavailable IGF-I is apparently not different, suggesting that any possible safety issues related to elevated IGF-I are similar in both groups. Copyright © 2010 by The Endocrine Society. Source

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