Auteur(s)
Si plusieurs auteurs, séparez les par des virgules
Mots-clés
278 résultat(s) trouvé(s)
2015;87(18):9234–9242
Voir le résumé
P289
Beucher L - Dervilly-Pinel G - Prevost S - Monteau F - Le Bizec B
Determination of a large set of β-adrenergic agonists in animal matrices based on Ion Mobility and Mass Separations
Analytical Chemistry
While the coupling of traveling wave ion mobility spectrometry (TWIMS) and mass spectrometry is mainly reported for structural purposes, we studied its potential in enhancing compounds analysis such as growth promoters used in livestock animals at trace concentrations. β-Adrenergic agonists have been selected as model compounds since they exhibit a range of close physicochemical properties leading to analytical issues using classical approaches. In this paper, the potential of Synapt G2-S (Q-TWIM-TOF MS) has been investigated for sensitive and specific detection of a range of these synthetic phenethanolamines in various complex biological matrices (retina, meat, and urine) from bovine considered as relevant in the context of detecting β-adrenergic agonists use in animals. In particular, the specificity of the additional information provided by the TWIMS (i.e., collision cross section) together with the interest of the extra dimension of separation is discussed. © 2015 American Chemical Society.

2015;26:784-795
Voir le résumé
P288
Alexandre MC - Martin Agnoux A - Antignac JP - Boquien CY - David A - Desnots E - Ferchaud-Roucher V - Darmaun D - Parnet P
Perinatal protein restriction affects milk free amino acid and fatty acid profile in lactating rats; potential role on pup growth and metabolic status
Journal of Nutritional Biochemistry
Perinatal undernutrition affects not only fetal and neonatal growth but also adult health outcome, as suggested by the metabolic imprinting concept. Although maternal milk is the only channel through which nutrients are transferred from mother to offspring during the postnatal period, the impact of maternal undernutrition on milk composition is poorly understood. The present study investigates, in a rat model of nutritional programming, the effects of feeding an isocaloric, low-protein diet throughout gestation and lactation on milk composition and its possible consequences on offspring’s growth and metabolic status. We used an integrated methodological approach that combined targeted analyses of macronutrients, free amino acid and fatty acid content throughout lactation, with an untargeted mass-spectrometric-based metabolomic phenotyping. Whereas perinatal dietary protein restriction failed to alter milk protein content, it dramatically decreased the concentration of most free amino acids at the end of lactation. Interestingly, a decrease of several amino acids involved in insulin secretion or gluconeogenesis was observed, suggesting that maternal protein restriction during the perinatal period may impact the insulinotrophic effect of milk, which may, in turn, account for the slower growth of the suckled male offspring. Besides, the decrease in sulfur amino acids may alter redox status in the offspring. Maternal undernutrition was also associated with an increase in milk total fatty acid content, with modifications in their pattern. Altogether, our results show that milk composition is clearly influenced by maternal diet and suggest that alterations in milk composition may play a role in offspring growth and metabolic programming. © 2015 Elsevier Inc. All rights reserved.

2015;118:329-335
Voir le résumé
P287
Munschy C - Olivier N - Veyrand B - Marchand P
Occurrence of legacy and emerging halogenated organic contaminants in marine shellfish along French coasts
Chemosphere
Current contamination levels of selected legacy, currently-used and emerging halogenated contaminants were monitored in marine shellfish along French coastlines. The studied contaminants included polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), decabromodiphenylethane (DBDPE), hexabromobenzene (HBB), 2,20,4,40,5,50-hexabromobiphenyl (BB-153) and perfluorinated compounds (PFCs). BDE-47, BDE-209, BTBPE, HBB and a-HBCDD were detected in 100% of the analyzed samples, whereas BB-153, DBDPE and PFOS were detected at frequencies of 97%, 90% and 55%, respectively. Concentrations were in the pg.g-1 ww range and varied as follows: PFOS > BDE-47 ∼ a-HBCDD > BDE-209 > BTBPE ∼ DBDPE > HBB ∼ BB-153. Overall, non-PBDE Brominated Flame Retardants (BFRs) revealed concentrations between 3 and 59 times lower than those of PBDEs. PBDE pattern was dominated by BDE-47, followed by BDE-99 > BDE-100 > BDE-49 > BDE-209 > BDE-154; these 6 congeners represented 94% of the summed ten PBDEs. PFC pattern determination revealed PFOS as the predominant PFC in samples from the English Channel and Atlantic, whereas perfluorocarboxylic acids (PFCAs) prevailed in Mediterranean samples. Temporal trend investigations on archived samples from the Mediterranean coast collected between 1981 and 2012 showed a prevalence of PFOS until 1998; PFCAs subsequently increased and became more abundant than PFOS. High levels of PFCAs were observed until 2008, followed by a decrease and stabilization in 2010–2012. Amongst PFCAs, perfluorotridecanoic acid (PFTrDA) and perfluoroundecanoic acid (PFUnA) were predominant and exhibited similar time trends, suggesting similar sources at the investigated site, home to major industrial activity. © 2014 Elsevier Ltd. All rights reserved.

2015; 4:27. DOI 10.1186/s40064-015-0790-4
Voir le résumé
P286
Sévère S - Marchand P - Guiffard I - Morio F - Venisseau A - Veyrand B - Le Bizec B - Antignac JP - Abadie J
Pollutants in pet dogs: a model for environmental links to breast cancer
SpringerPlus
Purpose: Invasive breast carcinoma is the most common cancer in women as in non-ovariectomised pet dogs, which are already identified as a valuable spontaneous preclinical model for that disease. Geographical and time trends suggest that environmental factors may play an important role in the etiology and pathogenesis of breast cancer. Persistent organic pollutants (POPs) fit perfectly with these trends and are known to interact with hormonal receptors implicated in breast cancer subtyping. The aim of this innovating study was to evaluate the interest of the companion dog model in assessing chemical exposure and breast cancer associations, in order to identify common etiological features with the human disease in a context of comparative oncology. Methods: We monitored a hundred of molecules belonging to a large panel of POPs (dioxins, dioxin-like and non dioxin-like polychlorobisphenyls, organochlorine pesticides, brominated flame retardants, perfluorinated alkylated substances) in companion dogs diagnosed for mammary adenocarcinoma (n = 54) and non cancer controls (n = 47). Results: All targeted chemical families were able to be detected in canine samples. We identified pollutants associated with mammary cancer belonging to the dioxin like-PCB family (notably PCB-118, -156, -105, -114) that were already pointed out in human epidemiological studies on breast cancer, and that fit with the fundamental role of the Aryl Hydrocarbon Receptor in the promotion of breast cancer. Conclusions: Similarities observed in the spontaneous dog model are very helpful to progress in interpretation of human breast cancer-environment relationships. This study provides a new insight focusing on this discrete but recurrent signature.

2015;407:2485–2497
Voir le résumé
P285
Deceuninck Y - Bichon E - Marchand P - Boquien CY - Legrand A - Boscher C - Antignac JP - Le Bizec B
Determination of bisphenol A and related substitutes/analogues in human breast milk using gas chromatography-tandem mass spectrometry
Analytical and Bioanalytical Chemistry
Bisphenol A (BPA) is an industrial chemical widely used in the production of polycarbonate and epoxy resins. Identified as an endocrine-disrupting chemical (EDC), BPA is a matter of existing or ongoing restrictive regulations and then is increasingly being replaced by other analogues used as BPA’s substitutes. Human biomonitoring studies focusing on both BPA and emerging related analogues consequently appear as a requirement either for documenting the efficiency of regulatory actions toward BPA and for fuelling incoming risk assessment studies toward BPA’s substitutes. In particular, the increasing concern about the late effects consecutive to early exposures naturally identify human breast milk as a target biological matrix of interest for priority exposure assessment focused on critical sub-populations such as pregnant women, fetuses, and/or newborns. In this context, an accurate and sensitive analytical method based on gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) was developed for the quantification of 18 BBPA-like compounds in breast milk samples at trace levels (<0.05 μg.kg-1). The method includes a preliminary protein precipitation step followed by two successive solid phase extraction (SPE) stages. Quantification of the targeted compounds was achieved according to the isotopic dilution method using 13C12-BPA as internal standard. The method was validated according to current EU guidelines and criteria. Linearity (R2) was better than 0.99 for each molecule within the concentration range 0-5 μg.kg-1. The detection and quantification limits ranged from 0.001 to 0.030 μg.kg-1 and from 0.002 to 0.050 μg.kg-1, respectively. The analytical method was successfully applied to the first set of human breast milk samples (n=30) originating from French women in the Region Pays-de-la-Loire. The measured levels of BPA were found in the <LOQ-1.16 μg.kg-1 range. BPS was detected in only one sample at 0.23 μg.kg-1, while the other targeted molecules were not detected. The proposed methodology then appeared suitable for the further monitoring of a potential decrease of BPA levels and an increase of other BPA analogue levels as reflective of the expected incoming trend in terms of human exposure. © Springer-Verlag Berlin Heidelberg 2015.

2015;407:4473–4484
Voir le résumé
P284
Doué M - Dervilly-Pinel G - Pouponneau K - Monteau F - Le Bizec B
Analysis of glucuronide and sulfate steroids in urine by ultra-high-performance supercritical-fluid chromatography hyphenated tandem mass spectrometry
Analytical and Bioanalytical Chemistry
Profiling conjugated urinary steroids to detect anabolic-steroid misuse is recognized as an efficient analytical strategy in both chemical-food-safety and anti-doping fields. The relevance and robustness of such profiling rely on the analysis of glucuronide and sulfate steroids, which is expected to have properties including accuracy, specificity, sensitivity, and, if possible, rapidity. In this context, the ability of ultrahigh-performance supercritical-fluid chromatography (UHPSFC) hyphenated tandem mass spectrometry (MS–MS) to provide reliable and accurate phase II analysis of steroids was assessed. Four stationary phases with sub-2 μm particles (BEH, BEH 2-ethyl-pyridine, HSS C18 SB, and CSH fluorophenyl) were screened for their capacity to separate several conjugated steroid isomers. Analytical conditions including stationary phase, modifier composition and percentage, back pressure, column temperature, and composition and flow rate of make-up solvent were investigated to improve the separation and/or the sensitivity. Thus, an analytical procedure enabling the analysis of eight glucuronide and 12 sulfate steroids by two different methods in 12 and 15 min, respectively, was optimized. The two procedures were evaluated, and UHPSFC–MS–MS analysis revealed its ability to provide sensitive (limits of quantification: 0.1 ng.mL-1 and 0.5 ng.mL-1 for sulfate and glucuronide steroids, respectively) and reliable quantitative performance (R2>0.995, RSD<20 %, and bias<30 %) through the use of suitable labeled internal standards. Comparison with UHPLC–MS–MS was performed, and UHPSFC–MS–MS obtained better performance in terms of sensitivity. Finally, as a proof of concept, this so-called green technology was used in a chemical-foodsafety context to profile steroid conjugates in urine samples from bovines treated with estradiol. © Springer-Verlag Berlin Heidelberg 2015.

2015;63:1339−1346
Voir le résumé
P282
Wauters J - Vanden Bussche J - Le Bizec B - Kiebooms JAL - Dervilly-Pinel G - Prevost S - Wozniak B - Sterk4 SS - Grønningen D - Kennedy DG - Russell S - Delahaut P - Vanhaecke L
Towards a new European threshold to discriminate illegally administered from naturally occurring thiouracil in livestock
Journal of Agricultural and Food Chemistry
Thiouracil is a thyrostat inhibiting the thyroid function, resulting in fraudulent weight gain if applied in the fattening of livestock. The latter abuse is strictly forbidden and monitored in the European Union. Recently, endogenous sources of thiouracil were identified after frequently monitoring low-level thiouracil positive urine samples and a “recommend concentration” (RC) of 10 μg/L was suggested by the EURL to facilitate decision-making. However, the systematic occurrence of urine samples exceeding the RC led to demands for international surveys defining an epidemiologic threshold. Therefore, six European member states (France, Poland, The Netherlands, United Kingdom, Norway, and Belgium) have shared their official thiouracil data (2010−2012) collected from bovines, porcines, and small livestock with 95 and 99% percentiles of 8.1 and 18.2 μg/L for bovines (n = 3894); 7.4 and 13.5 μg/L for porcines (n = 654); and 7.4 μg/L (95% only) for small livestock (n = 85), respectively. Bovine percentiles decreased with the animal age (nonadults had significantly higher levels for bovines), and higher levels were observed in male bovines compared to female bovines. © 2015 American Chemical Society.

2015;407:4343–4349
Voir le résumé
P281
Doué M - Dervilly-Pinel G - Cesbron N - Stefani A - Moro L - Biancotto G - Le Bizec B
Clinical biochemical and hormonal profiling in plasma: a promising strategy to predict growth hormone abuse in cattle.
Analytical and Bioanalytical Chemistry
Recombinant bovine somatotrophin (rbST) is widely used in some countries to increase milk production. Since 1994, both marketing and use of this substance have been prohibited within the European Union. In this context, the targeted plasma biochemical and hormonal profiling was assessed as a potential screening strategy to highlight rbST (ab)use in cattle. Twenty-one routinely measured clinical blood parameters, representative of main biological profiles (energetic, proteic, etc.), were measured in the plasma of six lactating cows before and after rbST treatment throughout a 23-day study period. Appropriate multivariate statistical analyses [principal component analysis (PCA) and orthogonal partial least square (OPLS)] enabled discriminating animal samples before and after treatment (days 0 vs. 2 to 9, P=2.10−9) and highlighted the five most relevant blood parameters in this discrimination. Based on each five-analyte contribution, a simple mathematically weighted equation was suggested to predict the status of samples. A suspicious threshold was proposed, and the model was further tested with the status prediction of the supplementary samples from untreated (n=20) and treated cows (n=22). The calculated false-positive (10 %) and false-negative (4.5 %) rates were in accordance with the EU requirements for screening methods. Although the model needs to be further validated with additional samples, such targeted plasma biochemical and hormonal profiling already appears as a potential promising screening strategy to highlight rbST (ab)use in cattle. © Springer-Verlag Berlin Heidelberg 2015.

2015;1408:169-177
Voir le résumé
P280
Bichon E - Guiffard I - Venisseau A - Marchand P - Antignac JP - Le Bizec B
Ultra-trace quantification method for chlordecone in human fluids and tissues
Journal of Chromatography A
Chlordecone is an organochlorine pesticide (OCP) considered as a Persistent Organic Pollutant (POP) as it persists in the environment, bio-accumulates through the food web, causes adverse effects to human health and the environment and transports across international boundaries far from its sources. The atypical physico-chemical properties of chlordecone make its inclusion in classical analytical approaches non applicable. The aim of our work was to include chlordecone in a multi organochlorine residue method preventing any degradation during the analytical process and thus allowing quantification at ppt (ng.kg-1 or ng.kg-1) levels for a wide range of OCPs in breast milk, human serum and adipose tissue. After GC–HRMS vs. MS/MS and EI vs. APCI comparisons, the major improvement in terms of sensitivity was found indecreasing the length and film thickness of the gas chromatography column. Thanks to a linear correlation between relative response and quantity of chlordecone injected, LC-(ESI-)-MS/MS was finally preferred. An acetonitrile based gradient optimized on a C30 core shell HPLC column has led to reaching limits of quantification as low as 8 ng.kg-1, 25 pg.mL-1 and 0.2 ng.g-1 fat for breast milk, serum and adipose tissue, respectively, allowing multiresidue OCP quantification at concentration levels compatible with biomonitoring purposes and pre-requisites.©2015 Elsevier B.V. All rights reserved.

2015;196:211-219
Voir le résumé
P279
Cariou R - Larvor F - Monteau F - Marchand P - Bichon E - Dervilly-Pinel G - Antignac JP - Le Bizec B
Measurement of Phthalates Diesters in Food Using Gas Chromatography-Tandem Mass Spectrometry
Food Chemistry
An analytical strategy dedicated to 4 major phthalate diesters (DiBP, DnBP, BBzP and DEHP) monitoring in food items has been developed and validated according to normalized guidelines. The method has been applied to a wide range of foodstuffs (n = 54) to generate first-ever occurrence data at the French level. This method involves separation and detection using gas chromatography coupled to tandem mass spectrometry, in electron ionisation with highly specific selected reaction monitoring, quantification being performed according to the isotope dilution principle. A particular attention has been paid to background contamination management at any stage of the analytical process, from the sampling to the expression of the results. Limits of reporting, defined as statistically different from background contamination, were found to be 2.7, 0.53, 0.18 and 3.4 µg.kg-1, and relative combined uncertainties were finally found to be 7.6%, 12.2%, 12.0% and 14.1%, for DiBP, DnBP, BBzP and DEHP, respectively. © 2015 Elsevier Ltd. All rights reserved.

« Page précédente1234567891011Page suivante »