Identification of Antigenic Proteins from Lichtheimia corymbifera for Farmer's Lung Disease Diagnosis.

The use of recombinant antigens has been shown to improve both the sensitivity and the standardization of the serological diagnosis of Farmer's lung disease (FLD). The aim of this study was to complete the panel of recombinant antigens available for FLD serodiagnosis with antigens of Lichtheimia corymbifera, known to be involved in FLD. L. corymbifera proteins were thus separated by 2D electrophoresis and subjected to western blotting with sera from 7 patients with FLD and 9 healthy exposed controls (HEC). FLD-associated immunoreactive proteins were identified by mass spectrometry based on a protein database specifically created for this study and subsequently produced as recombinant antigens. The ability of recombinant antigens to discriminate patients with FLD from controls was assessed by ELISA performed with sera from FLD patients (n = 41) and controls (n = 43) recruited from five university hospital pneumology departments of France and Switzerland. Forty-one FLD-associated immunoreactive proteins from L. corymbifera were identified. Six of them were produced as recombinant antigens. With a sensitivity and specificity of 81.4 and 77.3% respectively, dihydrolipoyl dehydrogenase was the most effective antigen for discriminating FLD patients from HEC. ELISA performed with the putative proteasome subunit alpha type as an antigen was especially specific (88.6%) and could thus be used for FLD confirmation. The production of recombinant antigens from L. corymbifera represents an additional step towards the development of a standardized ELISA kit for FLD diagnosis

Evaluation of the toxicity of prorocentrum species by liquid chromatography mass-spectrometry and cell-based assay

Dinoflagellates belonging to the genus Prorocentrum were studied for toxicological and toxin production properties by cell assays and liquid chromatographic methods, using fluorescence and mass-spectrometry detection (LC-FD, LC-MS). Cytotoxicity characterised by IC50 and morphological changes was examined. IC50 ranged from 2.103 cell equivalents mL-1 for P. cf faustiae to 133.103 for P. rhathymum. Morphological changes such as rounding and membrane blebbing were observed in fibroblasts exposed to Prorocentrum belizeanum and all Prorocentrum lima from Malaysia suggesting the presence of okadaic acid (OA). Analytical measurements confirmed the production of OA. However toxicity not correlated with the presence of OA suggests the production of derivates of OA or others toxin

Premières naissances en France après transfert d’embryons équins génotypés et cryoconservés

National audienc

The toxicity and intraspecific variability of Alexandrium andersonii Balech

The toxicity of Alexandrium andersonii Balech is unclear and its intraspecific variability has yet to be studied. To address these gaps in our knowledge, in the present work five strains of A. andersonii from four different localities were characterized. The results showed that despite genetic homogeneity in the 5.8-ITS (internal transcribed spacer) and large subunit (LSU) regions and similar growth rates, strains originating from different locations varied with respect to cell size, the ratios of certain pigments, and their growth patterns. Cultures of the strains grown at 20 °C were analyzed for toxicity using four different methodologies. The two officially established methods, mouse bioassay and high-performance liquid chromatography with fluorescence detection (HPLC-FLD) and post-column reaction analysis of PSP toxins, failed to show the toxicity of any strain. Strains grown at 14 °C were also negative for PSP toxins by HPLC-FLD. However, strains grown at 20 °C exhibited both a response characteristic of the presence of toxin-inhibiting voltage-gated sodium channels, as demonstrated in a neuroblastoma neuro-2a cell-based assay, as well as hemolytic activity in a sheep red blood cell assay.Versión del editor3,083

Refinement and Difference for Probabilistic Automata

International audienceThis paper studies a difference operator for stochastic systems whose specifications are represented by Abstract Probabilistic Automata (APAs). In the case refinement fails between two specifications, the target of this operator is to produce a specification APA that represents all witness PAs of this failure. Our contribution is an algorithm that allows to approximate the difference of two deterministic APAs with arbitrary precision. Our technique relies on new quantitative notions of distances between APAs used to assess convergence of the approximations as well as on an in-depth inspection of the refinement relation for APAs. The procedure is effective and not more complex than refinement checking