Orderly expression of B cell antigens during the in vitro differentiation of nonmalignant human p... more Orderly expression of B cell antigens during the in vitro differentiation of nonmalignant human pre-B cells.
Biofilters have been implemented in urban areas due to their ability to improve road runoff quali... more Biofilters have been implemented in urban areas due to their ability to improve road runoff quality. However, little is known about the role of soil microorganisms and plants on pollutant remediation in planted swales. Therefore, four large-scale outdoor mesocosms were built and co-contaminated with metals and model polycyclic aromatic hydrocarbons (PAHs) (phenanthrene (Phen), pyrene (Pyr) and benzo[a]pyrene (BaP)), to better understand the complex functioning of swale-like environments. Three macrophyte plant species were tested for enhanced remediation of PAHs: Juncus effusus, Iris pseudacorus, Phalaris arundinacea and a grass mix. Longterm dynamics of PAHs in water outflow and soil was studied. Results showed that only 0.07 to 0.22% of total PAHs were released in water outflow after one year. Two years after contamination, soil sample analyses showed a dissipation of 99.6% for Phen and 99.4% for Pyr whatever the mesocosm considered and ranging from 75.5 to 91% for BaP, depending on plant species. Furthermore, dissipation time-courses may be described by a biphasic process. Experiments showed that the grass mix facilitated BaP long-term biodegradation. Grass appeared also to be the best filter for suspended solids because of its dense rhizosphere, which prevents the transfer of BaP to groundwater.
HAL (Le Centre pour la Communication Scientifique Directe), Feb 15, 2013
National audienceLes hydrocarbures aromatiques polycycliques (HAP), polluants toxiques persistant... more National audienceLes hydrocarbures aromatiques polycycliques (HAP), polluants toxiques persistants, présentent un caractère de géo-accumulation. En fonction de leur forme chimique et des caractéristiques du sol, ils sont plus ou moins fortement séquestrés et l'efficacité des procédés de bioremédiation est alors intimement liée à la biodisponibilité des HAP pour les micro-organismes dégradeurs du sol. Le but de cette étude est donc (i) de mettre au point une technique simple et rapide afin d'évaluer la biodisponibilité des HAP dans les sols (ii) de définir les communautés bactériennes impliquées dans la dégradation des HAP et (iii) de comprendre la relation entre la biodégradation des HAP, leur biodisponibilité, la nature des sols et les communautés bactériennes dégradant le phénanthrène. (i) Les techniques d'extraction drastiques généralement mises en oeuvre pour extraire les HAP (Soxhlet, extraction assistée par micro-ondes MAE, ou par solvants sous pression) donnent la teneur pseudo-totale en HAP, mais ne permettent pas d'accéder à la fraction labile des HAP. Des méthodes d'extraction douces en phase aqueuse, utilisant des agents solubilisants, sont plus susceptibles d'accéder à cette fraction de HAP réellement biodisponibles. Des additifs tels que des agents tensioactifs synthétiques, des émulsions, des biosurfactants (produits par des bactéries), des cyclodextrines et des liquides ioniques micellaires ont été testés sur 5 sols naturels, de caractéristiques géochimiques très différentes (taux de matière organique, d'argiles, pH…). Les capacités d'extraction en phase aqueuse, en présence des différents additifs, ont ensuite été comparées aux extractions pseudo-totales effectuées par MAE, afin d'établir si le ratio entre HAP labiles et HAP totaux était corrélé aux caractéristiques de rétention des sols. (ii) Des tests de croissance en milieu minimum, en présence de Phénanthrène (PHE) comme seule source de carbone, ont été réalisés sur une centaine de souches provenant d'un des sols d'étude, permettant de mettre en évidence 2 souches significativement dégradantes, dont une produit un biosurfactant. Le dosage par HPLC-FLD du PHE résiduel dans les tubes de culture a permis de valider les résultats des tests de croissance bactérienne. Des études de la cinétique de dissipation naturelle de 7 HAP dans les 5 sols d'étude ont été parallèlement réalisées en microcosmes, et ont présenté des résultats contrastés semblant être plutôt reliés au paramètre bactérien qu'aux caractéristiques physico-chimiques des sols. (iii) Au final, une analyse en composantes principales (ACP) a permis de corréler (ou non) la biodégradation des HAP en 3 mois à certaines caractéristiques des sols, à leur biodisponibilité et au nombre de bactéries cultivables dégradant le phénanthrène
Objective. To identify a new autoantigen/ autoantibody population in rheumatoid arthritis (RA) se... more Objective. To identify a new autoantigen/ autoantibody population in rheumatoid arthritis (RA) sera. Methods. Following a population-based recruitment effort, 255 patients with very early arthritis (median disease duration 4 months) were studied using different clinical, biologic, and radiologic assessments. After a followup period of 1 year, patients were classified as having RA (n ؍ 145), non-RA rheumatic diseases (n ؍ 70), and undifferentiated arthritis (n ؍ 40). Patients' sera were analyzed by one-dimensional (1D) and 2D Western blotting. The recognized 50-kd protein was analyzed by matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry (MS). RA serum reactivities were evaluated against the recombinant protein synthesized by an in vitro coupled transcription-translation system. Results. On 1D Western blots, 36 of the 145 RA sera bound to a 50-kd polypeptide. On 2D Western blots, anti-50-kd؉ RA sera recognized a triplet of isoelectric point 6.5-7.0 and a molecular mass of 50 kd. The 3 spots of the triplet were analyzed by MALDI-TOF MS and were shown to correspond to human ␣-enolase. A goat anti-enolase antiserum, which recognized a band comigrating with the 50-kd antigen on 1D Western blots, gave a labeling pattern on 2D Western blots similar to that observed with anti-50-kd؉ RA sera. Among the 36 RA sera that identified ␣-enolase in protein maps, only 8 recognized the recombinant (unmodified) ␣-enolase. The specificity of anti-␣-enolase antibodies for RA was 97.1%. Half of the anti-␣-enolase-positive RA patients were negative for both rheumatoid factor and antifilaggrin antibodies. The presence of anti-␣-enolase antibodies was the greatest predictive factor of radiologic progression in the first 66 RA patients included. Conclusion. Autoantibodies to ␣-enolase, an enzyme of the glycolytic pathway, are present in the sera of patients with very early RA and have potential diagnostic and prognostic value for RA.
ABSTRACTHydrocarbon contamination, which can alter the physiochemical and biological properties o... more ABSTRACTHydrocarbon contamination, which can alter the physiochemical and biological properties of the subsurface, can be monitored by using geochemical analyses and integrated geophysical techniques. Electrical resistivity tomography, induced polarization, ground‐penetrating radar, and self‐potential methods were used in this work to characterise the hydrocarbon contamination and investigate the geoelectrical properties of a site impacted by an aged hydrocarbon plume. Throughout the investigation, geoelectrical measurements supported the conductive plume model and consistently recorded low‐resistivity anomalies and high‐chargeability values in the contaminated aquifer. Furthermore, the low‐resistivity anomalies were found to be coincident with regions of ground‐penetrating radar attenuated reflections and significant negative self‐potential anomalies associated with oxidation–reduction processes. These findings were supported by the geochemical measurements, which revealed depleted concentrations of terminal electron acceptors (TEAs) and elevated amounts of ions and total dissolved solids, which could be attributed to bacterial biodegradation of hydrocarbons. The study showed that biological alterations of hydrocarbon‐induced subtle changes in the pore water biogeochemistry, which consequently modified the geophysical properties of the contaminated sediments. Based on these observations, the extent of groundwater contamination was delineated according to the geophysical contrast between the contaminated and clean zones. The combination of different geophysical methods constrained by geochemical point measurements provided insight on the different processes that might have modified the soil and groundwater biogeochemical properties.
HAL (Le Centre pour la Communication Scientifique Directe), 2005
Analysis of virtual two-dimensional gels based upon affinity capillary electrophoresis hyphenated... more Analysis of virtual two-dimensional gels based upon affinity capillary electrophoresis hyphenated to ion trap-mass spectrometry Affinity capillary electrophoresis (ACE) is a robust tool for the study of noncovalent biomolecular interactions and to determine the binding constants. It is advantageous due to the speed of analysis, the high and reproducible separation efficiencies, the low consumption of analytes, the ability to study several interactions at the same time, and to cover a wide range of affinity. The use of an ion trap-mass spectrometer as a sensitive and specific detector, coupled on-line with a classical UV detector, permits extracting simultaneously the electropherograms corresponding to each ionic species. The mass spectra, acquired by scanning the results of a first separation due to ACE, were assimilated into a virtual two-dimensional (2-D) gel. We developed a software application, which was designed to create and analyze these virtual 2-D gels. The validity of this new analytical tool for probing biomolecular interactions has been demonstrated on mixtures of antibiotics of the vancomycin group and several dipeptide substrates. Using the dynamic equilibrium affinity electrophoresis approach, we have shown that molecular components interacting with a low affinity are easily located on the virtual 2-D gels, and that binding constants and stoichiometry of the interactions can be assessed. As the binding constants derived from ACE-electrospray ionizationmass spectrometry (ESI-MS) are unreliable, they must only be determined with the UV detector.
A simple, efficient matrix solid phase dispersive extraction (MSPD) method was optimised to analy... more A simple, efficient matrix solid phase dispersive extraction (MSPD) method was optimised to analyse simultaneously polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs) from sediments, and was compared to microwave-assisted extraction (MAE). New dispersing agents were tested to improve MSPD extraction. 3-chloropropyl-bonded silica particles, in addition to Florisil, increased significantly the polyaromatics desorption capacity. A compromise was found for eluting both families of compounds from sediments, using a small volume of hexane/acetone. Low procedural detection limits could be reached (0.06-0.22 ng g − 1 and 0.3-1.1 ng g − 1 for PAHs and PCBs, respectively). Mean total extraction recoveries were good for PAHs (>67%, depending on the sediment) and for PCBs (>89%), with good precision (6-9% and 4-10% inter-day precision for PAHs and PCBs, respectively). Higher recoveries for PCBs could be reached in comparison with formerly developed sonication or Soxhlet extraction methods, but also with MAE. MSPD offered significant decrease of sample amount, of solvent consumption and allowed more efficient cleaning of the sediment matrix, leading to less matrix effects compared to MAE, removing lots of interfering compounds without additional purification step. The robustness of the MSPD methodology could be demonstrated extracting quantitatively sediments from different sources and with various mineralogical characteristics.
Polycyclic aromatic hydrocarbons (PAHs) are persistent pollutants that accumulate in sediments, w... more Polycyclic aromatic hydrocarbons (PAHs) are persistent pollutants that accumulate in sediments, where they may be turned into more toxic oxygenated metabolites (oxy-PAHs). Two methodologies were screened for a multi-residue analysis of two different families of oxy-PAHs from sediments: hydroxylated PAHs (OH-PAHs) and carbonyl-PAHs (quinones). Microwaveassisted extraction (MAE), which has never been used for their simultaneous extraction, was optimized based on (1) a fractional factorial design to screen the influential factors and (2) a central composite design to obtain the best compromise for optimal extraction conditions, which were 128 °C, 26 mL of acetonitrile/methylene chloride (90/10) and 10 min duration. Individual recoveries were in the range 73.9-118%. Then GC-MS and HPLC coupled to UV and fluorescence (FLD) detectors were investigated for quantification of traces. OH-PAHs and quinones had to be derivatized before GC-MS. Acetylation of quinones was improved and limits of detection (LODs) were decreased 2.7-53 fold, with the highest benefit for orthoquinones. There was no real advantage in using HPLC-UV instead of GC-MS in terms of carbonyl-PAH detection sensitivity, but OH-PAH LODs were decreased 30-to 140-fold using HPLC-FLD. Despite this advantage, MAE-GC-MS appeared the best way to analyze oxy-PAHs at trace levels from naturally contaminated sediment matrices, because confirmation of their presence in extracts was more reliable.
The potential of electrospray tandem mass spectrometry using a quadrupole-time-of-flight tandem m... more The potential of electrospray tandem mass spectrometry using a quadrupole-time-of-flight tandem mass spectrometer was evaluated for the identification of two unknown proteins from one-dimensional polyacrylamide gel electrophoresis (1-D-PAGE). Two proteins from cellular cultures of mammary epithelia were purified by 1D-PAGE. Their identification was achieved using peptide sequence tags generated by LC/Q-TOF-MS/MS, whereas MALDI-TOF mass mapping failed for these proteins obtained from simple 1D-PAGE separation.
HAL (Le Centre pour la Communication Scientifique Directe), Jun 13, 2016
National audiencePolycyclic aromatic hydrocarbons (PAHs) are toxic and carcinogenic pollutants pr... more National audiencePolycyclic aromatic hydrocarbons (PAHs) are toxic and carcinogenic pollutants produced in majority by incomplete combustion processes in industrialized and urbanized areas. After being emitted in atmosphere, these persistent contaminants are deposited to soils or sediments. Even if persistent, some can be partially degraded (photodegradation, biodegradation, chemical oxidation) and they lead to oxygenated metabolites (oxy-PAHs) which can be more toxic than their parent PAH. Oxy-PAHs are less measured than PAHs in sediments and this study aims to compare different analytical tools in order to extract and quantify a mixture of four hydroxylated PAHs (OH-PAHs) and four carbonyl PAHs (quinones) in sediments. Methodologies: Two analytical systems-HPLC with on-line UV and fluorescence detectors (HPLC-UV-FLD) and GC coupled to a mass spectrometer (GC-MS)-were compared to separate and quantify oxy-PAHs. Microwave assisted extraction (MAE) was optimized to extract oxy-PAHs from sediments. Results: First OH-PAHs and quinones were analyzed in HPLC with on-line UV and fluorimetric detectors. OH-PAHs were detected with the sensitive FLD, but the non-fluorescent quinones were detected with UV. The limits of detection (LOD)s obtained were in the range (2-3)×10-4 mg/L for OH-PAHs and (2-3)×10-3 mg/L for quinones. Second, even if GC-MS is not well adapted to the analysis of the thermodegradable OH-PAHs and quinones without any derivatization step, it was used because of the advantages of the detector in terms of identification and the advantages of GC in terms of efficiency. Without derivatization, only two of the four quinones were detected in the range 1-10 mg/L (LODs=0.3-1.2 mg/L) and LODs were neither very satisfying for the four OH-PAHs (0.18-0.6 mg/L). So two derivatization processes were optimized, comparing to literature: one for silylation of OH-PAHs, one for acetylation of quinones. Silylation using BSTFA/TCMS 99/1 was enhanced using a mixture of catalyst solvents (pyridine/ethyle acetate) and finding the appropriate reaction duration (5-60 minutes). Acetylation was optimized at different steps of the process, including the initial volume of compounds to derivatize, the added amounts of Zn (0.1-0.25 g), the nature of the derivatization product (acetic anhydride, heptafluorobutyric acid…) and the liquid/liquid extraction at the end of the process. After derivatization, LODs were decreased by a factor 3 for OH-PAHs and by a factor 4 for quinones, all the quinones being now detected. Thereafter, quinones and OH-PAHs were extracted from spiked sediments using microwave assisted extraction (MAE) followed by GC-MS analysis. Several mixtures of solvents of different volumes (10-25 mL) and using different extraction temperatures (80-120°C) were tested to obtain the best recovery yields. Satisfactory recoveries could be obtained for quinones (70-96%) and for OH-PAHs (70-104%). Temperature was a critical factor which had to be controlled to avoid oxy-PAHs degradation during the MAE extraction process. Conclusion: Even if MAE-GC-MS was satisfactory to analyze these oxy-PAHs, MAE optimization has to be carried on to obtain a most appropriate extraction solvent mixture, allowing a direct injection in the HPLC-UV-FLD system, which is more sensitive than GC-MS and does not necessitate a previous long derivatization step
HAL (Le Centre pour la Communication Scientifique Directe), Mar 28, 2017
In this study, an automated method for the simultaneous determination of polycyclic aromatic hydr... more In this study, an automated method for the simultaneous determination of polycyclic aromatic hydrocarbons (PAHs) and their chlorination by-products in drinking water was developed based on online solid-phase microextraction-gas chromatography-mass spectrometry. The main focus was the optimisation of the solid-phase microextraction step. The influence of the agitation rate, type of fibre, desorption time, extraction time, extraction temperature, desorption temperature, and solvent addition was examined. The method was developed and validated using a mixture of 17 PAHs, 11 potential chlorination by-products (chlorinated and oxidised PAHs) and 6 deuterated standards. The limit of quantification was 10 ng/L for all target compounds. The validated method was used to analyse drinking water samples from three different drinking water distribution networks and the presumably coal tar-based pipe coatings of two pipe sections. A number of PAHs were detected in all three networks although individual compositions varied. Several PAH chlorination by-products (anthraquinone, fluorenone, cyclopenta[d,e,f]phenanthrenone, 3-chlorofluoranthene, and 1-chloropyrene) were also found, their presence correlating closely with that of their respective parent compounds. Their concentrations were always below 100 ng/L. In the coatings, all PAHs targeted were detected although concentrations varied between the two coatings (76-12,635 mg/kg and 12-6295 mg/kg, respectively). A number of chlorination by-products (anthraquinone, fluorenone, cyclopenta[d,e,f]phenanthrenone, 3-chlorofluoranthene, and 1-chloropyrene) were also detected (from 40 to 985 mg/kg), suggesting that the reaction of PAHs with disinfectant agents takes place in the coatings and not in the water phase after migration.
A simple, efficient matrix solid phase dispersive extraction (MSPD) method was optimised to analy... more A simple, efficient matrix solid phase dispersive extraction (MSPD) method was optimised to analyse simultaneously polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs) from sediments, and was compared to microwave-assisted extraction (MAE). New dispersing agents were tested to improve MSPD extraction. 3-chloropropyl-bonded silica particles, in addition to Florisil, increased significantly the polyaromatics desorption capacity. A compromise was found for eluting both families of compounds from sediments, using a small volume of hexane/acetone. Low procedural detection limits could be reached (0.06-0.22 ng g − 1 and 0.3-1.1 ng g − 1 for PAHs and PCBs, respectively). Mean total extraction recoveries were good for PAHs (>67%, depending on the sediment) and for PCBs (>89%), with good precision (6-9% and 4-10% inter-day precision for PAHs and PCBs, respectively). Higher recoveries for PCBs could be reached in comparison with formerly developed sonication or Soxhlet extraction methods, but also with MAE. MSPD offered significant decrease of sample amount, of solvent consumption and allowed more efficient cleaning of the sediment matrix, leading to less matrix effects compared to MAE, removing lots of interfering compounds without additional purification step. The robustness of the MSPD methodology could be demonstrated extracting quantitatively sediments from different sources and with various mineralogical characteristics.
Orderly expression of B cell antigens during the in vitro differentiation of nonmalignant human p... more Orderly expression of B cell antigens during the in vitro differentiation of nonmalignant human pre-B cells.
Biofilters have been implemented in urban areas due to their ability to improve road runoff quali... more Biofilters have been implemented in urban areas due to their ability to improve road runoff quality. However, little is known about the role of soil microorganisms and plants on pollutant remediation in planted swales. Therefore, four large-scale outdoor mesocosms were built and co-contaminated with metals and model polycyclic aromatic hydrocarbons (PAHs) (phenanthrene (Phen), pyrene (Pyr) and benzo[a]pyrene (BaP)), to better understand the complex functioning of swale-like environments. Three macrophyte plant species were tested for enhanced remediation of PAHs: Juncus effusus, Iris pseudacorus, Phalaris arundinacea and a grass mix. Longterm dynamics of PAHs in water outflow and soil was studied. Results showed that only 0.07 to 0.22% of total PAHs were released in water outflow after one year. Two years after contamination, soil sample analyses showed a dissipation of 99.6% for Phen and 99.4% for Pyr whatever the mesocosm considered and ranging from 75.5 to 91% for BaP, depending on plant species. Furthermore, dissipation time-courses may be described by a biphasic process. Experiments showed that the grass mix facilitated BaP long-term biodegradation. Grass appeared also to be the best filter for suspended solids because of its dense rhizosphere, which prevents the transfer of BaP to groundwater.
HAL (Le Centre pour la Communication Scientifique Directe), Feb 15, 2013
National audienceLes hydrocarbures aromatiques polycycliques (HAP), polluants toxiques persistant... more National audienceLes hydrocarbures aromatiques polycycliques (HAP), polluants toxiques persistants, présentent un caractère de géo-accumulation. En fonction de leur forme chimique et des caractéristiques du sol, ils sont plus ou moins fortement séquestrés et l'efficacité des procédés de bioremédiation est alors intimement liée à la biodisponibilité des HAP pour les micro-organismes dégradeurs du sol. Le but de cette étude est donc (i) de mettre au point une technique simple et rapide afin d'évaluer la biodisponibilité des HAP dans les sols (ii) de définir les communautés bactériennes impliquées dans la dégradation des HAP et (iii) de comprendre la relation entre la biodégradation des HAP, leur biodisponibilité, la nature des sols et les communautés bactériennes dégradant le phénanthrène. (i) Les techniques d'extraction drastiques généralement mises en oeuvre pour extraire les HAP (Soxhlet, extraction assistée par micro-ondes MAE, ou par solvants sous pression) donnent la teneur pseudo-totale en HAP, mais ne permettent pas d'accéder à la fraction labile des HAP. Des méthodes d'extraction douces en phase aqueuse, utilisant des agents solubilisants, sont plus susceptibles d'accéder à cette fraction de HAP réellement biodisponibles. Des additifs tels que des agents tensioactifs synthétiques, des émulsions, des biosurfactants (produits par des bactéries), des cyclodextrines et des liquides ioniques micellaires ont été testés sur 5 sols naturels, de caractéristiques géochimiques très différentes (taux de matière organique, d'argiles, pH…). Les capacités d'extraction en phase aqueuse, en présence des différents additifs, ont ensuite été comparées aux extractions pseudo-totales effectuées par MAE, afin d'établir si le ratio entre HAP labiles et HAP totaux était corrélé aux caractéristiques de rétention des sols. (ii) Des tests de croissance en milieu minimum, en présence de Phénanthrène (PHE) comme seule source de carbone, ont été réalisés sur une centaine de souches provenant d'un des sols d'étude, permettant de mettre en évidence 2 souches significativement dégradantes, dont une produit un biosurfactant. Le dosage par HPLC-FLD du PHE résiduel dans les tubes de culture a permis de valider les résultats des tests de croissance bactérienne. Des études de la cinétique de dissipation naturelle de 7 HAP dans les 5 sols d'étude ont été parallèlement réalisées en microcosmes, et ont présenté des résultats contrastés semblant être plutôt reliés au paramètre bactérien qu'aux caractéristiques physico-chimiques des sols. (iii) Au final, une analyse en composantes principales (ACP) a permis de corréler (ou non) la biodégradation des HAP en 3 mois à certaines caractéristiques des sols, à leur biodisponibilité et au nombre de bactéries cultivables dégradant le phénanthrène
Objective. To identify a new autoantigen/ autoantibody population in rheumatoid arthritis (RA) se... more Objective. To identify a new autoantigen/ autoantibody population in rheumatoid arthritis (RA) sera. Methods. Following a population-based recruitment effort, 255 patients with very early arthritis (median disease duration 4 months) were studied using different clinical, biologic, and radiologic assessments. After a followup period of 1 year, patients were classified as having RA (n ؍ 145), non-RA rheumatic diseases (n ؍ 70), and undifferentiated arthritis (n ؍ 40). Patients' sera were analyzed by one-dimensional (1D) and 2D Western blotting. The recognized 50-kd protein was analyzed by matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry (MS). RA serum reactivities were evaluated against the recombinant protein synthesized by an in vitro coupled transcription-translation system. Results. On 1D Western blots, 36 of the 145 RA sera bound to a 50-kd polypeptide. On 2D Western blots, anti-50-kd؉ RA sera recognized a triplet of isoelectric point 6.5-7.0 and a molecular mass of 50 kd. The 3 spots of the triplet were analyzed by MALDI-TOF MS and were shown to correspond to human ␣-enolase. A goat anti-enolase antiserum, which recognized a band comigrating with the 50-kd antigen on 1D Western blots, gave a labeling pattern on 2D Western blots similar to that observed with anti-50-kd؉ RA sera. Among the 36 RA sera that identified ␣-enolase in protein maps, only 8 recognized the recombinant (unmodified) ␣-enolase. The specificity of anti-␣-enolase antibodies for RA was 97.1%. Half of the anti-␣-enolase-positive RA patients were negative for both rheumatoid factor and antifilaggrin antibodies. The presence of anti-␣-enolase antibodies was the greatest predictive factor of radiologic progression in the first 66 RA patients included. Conclusion. Autoantibodies to ␣-enolase, an enzyme of the glycolytic pathway, are present in the sera of patients with very early RA and have potential diagnostic and prognostic value for RA.
ABSTRACTHydrocarbon contamination, which can alter the physiochemical and biological properties o... more ABSTRACTHydrocarbon contamination, which can alter the physiochemical and biological properties of the subsurface, can be monitored by using geochemical analyses and integrated geophysical techniques. Electrical resistivity tomography, induced polarization, ground‐penetrating radar, and self‐potential methods were used in this work to characterise the hydrocarbon contamination and investigate the geoelectrical properties of a site impacted by an aged hydrocarbon plume. Throughout the investigation, geoelectrical measurements supported the conductive plume model and consistently recorded low‐resistivity anomalies and high‐chargeability values in the contaminated aquifer. Furthermore, the low‐resistivity anomalies were found to be coincident with regions of ground‐penetrating radar attenuated reflections and significant negative self‐potential anomalies associated with oxidation–reduction processes. These findings were supported by the geochemical measurements, which revealed depleted concentrations of terminal electron acceptors (TEAs) and elevated amounts of ions and total dissolved solids, which could be attributed to bacterial biodegradation of hydrocarbons. The study showed that biological alterations of hydrocarbon‐induced subtle changes in the pore water biogeochemistry, which consequently modified the geophysical properties of the contaminated sediments. Based on these observations, the extent of groundwater contamination was delineated according to the geophysical contrast between the contaminated and clean zones. The combination of different geophysical methods constrained by geochemical point measurements provided insight on the different processes that might have modified the soil and groundwater biogeochemical properties.
HAL (Le Centre pour la Communication Scientifique Directe), 2005
Analysis of virtual two-dimensional gels based upon affinity capillary electrophoresis hyphenated... more Analysis of virtual two-dimensional gels based upon affinity capillary electrophoresis hyphenated to ion trap-mass spectrometry Affinity capillary electrophoresis (ACE) is a robust tool for the study of noncovalent biomolecular interactions and to determine the binding constants. It is advantageous due to the speed of analysis, the high and reproducible separation efficiencies, the low consumption of analytes, the ability to study several interactions at the same time, and to cover a wide range of affinity. The use of an ion trap-mass spectrometer as a sensitive and specific detector, coupled on-line with a classical UV detector, permits extracting simultaneously the electropherograms corresponding to each ionic species. The mass spectra, acquired by scanning the results of a first separation due to ACE, were assimilated into a virtual two-dimensional (2-D) gel. We developed a software application, which was designed to create and analyze these virtual 2-D gels. The validity of this new analytical tool for probing biomolecular interactions has been demonstrated on mixtures of antibiotics of the vancomycin group and several dipeptide substrates. Using the dynamic equilibrium affinity electrophoresis approach, we have shown that molecular components interacting with a low affinity are easily located on the virtual 2-D gels, and that binding constants and stoichiometry of the interactions can be assessed. As the binding constants derived from ACE-electrospray ionizationmass spectrometry (ESI-MS) are unreliable, they must only be determined with the UV detector.
A simple, efficient matrix solid phase dispersive extraction (MSPD) method was optimised to analy... more A simple, efficient matrix solid phase dispersive extraction (MSPD) method was optimised to analyse simultaneously polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs) from sediments, and was compared to microwave-assisted extraction (MAE). New dispersing agents were tested to improve MSPD extraction. 3-chloropropyl-bonded silica particles, in addition to Florisil, increased significantly the polyaromatics desorption capacity. A compromise was found for eluting both families of compounds from sediments, using a small volume of hexane/acetone. Low procedural detection limits could be reached (0.06-0.22 ng g − 1 and 0.3-1.1 ng g − 1 for PAHs and PCBs, respectively). Mean total extraction recoveries were good for PAHs (>67%, depending on the sediment) and for PCBs (>89%), with good precision (6-9% and 4-10% inter-day precision for PAHs and PCBs, respectively). Higher recoveries for PCBs could be reached in comparison with formerly developed sonication or Soxhlet extraction methods, but also with MAE. MSPD offered significant decrease of sample amount, of solvent consumption and allowed more efficient cleaning of the sediment matrix, leading to less matrix effects compared to MAE, removing lots of interfering compounds without additional purification step. The robustness of the MSPD methodology could be demonstrated extracting quantitatively sediments from different sources and with various mineralogical characteristics.
Polycyclic aromatic hydrocarbons (PAHs) are persistent pollutants that accumulate in sediments, w... more Polycyclic aromatic hydrocarbons (PAHs) are persistent pollutants that accumulate in sediments, where they may be turned into more toxic oxygenated metabolites (oxy-PAHs). Two methodologies were screened for a multi-residue analysis of two different families of oxy-PAHs from sediments: hydroxylated PAHs (OH-PAHs) and carbonyl-PAHs (quinones). Microwaveassisted extraction (MAE), which has never been used for their simultaneous extraction, was optimized based on (1) a fractional factorial design to screen the influential factors and (2) a central composite design to obtain the best compromise for optimal extraction conditions, which were 128 °C, 26 mL of acetonitrile/methylene chloride (90/10) and 10 min duration. Individual recoveries were in the range 73.9-118%. Then GC-MS and HPLC coupled to UV and fluorescence (FLD) detectors were investigated for quantification of traces. OH-PAHs and quinones had to be derivatized before GC-MS. Acetylation of quinones was improved and limits of detection (LODs) were decreased 2.7-53 fold, with the highest benefit for orthoquinones. There was no real advantage in using HPLC-UV instead of GC-MS in terms of carbonyl-PAH detection sensitivity, but OH-PAH LODs were decreased 30-to 140-fold using HPLC-FLD. Despite this advantage, MAE-GC-MS appeared the best way to analyze oxy-PAHs at trace levels from naturally contaminated sediment matrices, because confirmation of their presence in extracts was more reliable.
The potential of electrospray tandem mass spectrometry using a quadrupole-time-of-flight tandem m... more The potential of electrospray tandem mass spectrometry using a quadrupole-time-of-flight tandem mass spectrometer was evaluated for the identification of two unknown proteins from one-dimensional polyacrylamide gel electrophoresis (1-D-PAGE). Two proteins from cellular cultures of mammary epithelia were purified by 1D-PAGE. Their identification was achieved using peptide sequence tags generated by LC/Q-TOF-MS/MS, whereas MALDI-TOF mass mapping failed for these proteins obtained from simple 1D-PAGE separation.
HAL (Le Centre pour la Communication Scientifique Directe), Jun 13, 2016
National audiencePolycyclic aromatic hydrocarbons (PAHs) are toxic and carcinogenic pollutants pr... more National audiencePolycyclic aromatic hydrocarbons (PAHs) are toxic and carcinogenic pollutants produced in majority by incomplete combustion processes in industrialized and urbanized areas. After being emitted in atmosphere, these persistent contaminants are deposited to soils or sediments. Even if persistent, some can be partially degraded (photodegradation, biodegradation, chemical oxidation) and they lead to oxygenated metabolites (oxy-PAHs) which can be more toxic than their parent PAH. Oxy-PAHs are less measured than PAHs in sediments and this study aims to compare different analytical tools in order to extract and quantify a mixture of four hydroxylated PAHs (OH-PAHs) and four carbonyl PAHs (quinones) in sediments. Methodologies: Two analytical systems-HPLC with on-line UV and fluorescence detectors (HPLC-UV-FLD) and GC coupled to a mass spectrometer (GC-MS)-were compared to separate and quantify oxy-PAHs. Microwave assisted extraction (MAE) was optimized to extract oxy-PAHs from sediments. Results: First OH-PAHs and quinones were analyzed in HPLC with on-line UV and fluorimetric detectors. OH-PAHs were detected with the sensitive FLD, but the non-fluorescent quinones were detected with UV. The limits of detection (LOD)s obtained were in the range (2-3)×10-4 mg/L for OH-PAHs and (2-3)×10-3 mg/L for quinones. Second, even if GC-MS is not well adapted to the analysis of the thermodegradable OH-PAHs and quinones without any derivatization step, it was used because of the advantages of the detector in terms of identification and the advantages of GC in terms of efficiency. Without derivatization, only two of the four quinones were detected in the range 1-10 mg/L (LODs=0.3-1.2 mg/L) and LODs were neither very satisfying for the four OH-PAHs (0.18-0.6 mg/L). So two derivatization processes were optimized, comparing to literature: one for silylation of OH-PAHs, one for acetylation of quinones. Silylation using BSTFA/TCMS 99/1 was enhanced using a mixture of catalyst solvents (pyridine/ethyle acetate) and finding the appropriate reaction duration (5-60 minutes). Acetylation was optimized at different steps of the process, including the initial volume of compounds to derivatize, the added amounts of Zn (0.1-0.25 g), the nature of the derivatization product (acetic anhydride, heptafluorobutyric acid…) and the liquid/liquid extraction at the end of the process. After derivatization, LODs were decreased by a factor 3 for OH-PAHs and by a factor 4 for quinones, all the quinones being now detected. Thereafter, quinones and OH-PAHs were extracted from spiked sediments using microwave assisted extraction (MAE) followed by GC-MS analysis. Several mixtures of solvents of different volumes (10-25 mL) and using different extraction temperatures (80-120°C) were tested to obtain the best recovery yields. Satisfactory recoveries could be obtained for quinones (70-96%) and for OH-PAHs (70-104%). Temperature was a critical factor which had to be controlled to avoid oxy-PAHs degradation during the MAE extraction process. Conclusion: Even if MAE-GC-MS was satisfactory to analyze these oxy-PAHs, MAE optimization has to be carried on to obtain a most appropriate extraction solvent mixture, allowing a direct injection in the HPLC-UV-FLD system, which is more sensitive than GC-MS and does not necessitate a previous long derivatization step
HAL (Le Centre pour la Communication Scientifique Directe), Mar 28, 2017
In this study, an automated method for the simultaneous determination of polycyclic aromatic hydr... more In this study, an automated method for the simultaneous determination of polycyclic aromatic hydrocarbons (PAHs) and their chlorination by-products in drinking water was developed based on online solid-phase microextraction-gas chromatography-mass spectrometry. The main focus was the optimisation of the solid-phase microextraction step. The influence of the agitation rate, type of fibre, desorption time, extraction time, extraction temperature, desorption temperature, and solvent addition was examined. The method was developed and validated using a mixture of 17 PAHs, 11 potential chlorination by-products (chlorinated and oxidised PAHs) and 6 deuterated standards. The limit of quantification was 10 ng/L for all target compounds. The validated method was used to analyse drinking water samples from three different drinking water distribution networks and the presumably coal tar-based pipe coatings of two pipe sections. A number of PAHs were detected in all three networks although individual compositions varied. Several PAH chlorination by-products (anthraquinone, fluorenone, cyclopenta[d,e,f]phenanthrenone, 3-chlorofluoranthene, and 1-chloropyrene) were also found, their presence correlating closely with that of their respective parent compounds. Their concentrations were always below 100 ng/L. In the coatings, all PAHs targeted were detected although concentrations varied between the two coatings (76-12,635 mg/kg and 12-6295 mg/kg, respectively). A number of chlorination by-products (anthraquinone, fluorenone, cyclopenta[d,e,f]phenanthrenone, 3-chlorofluoranthene, and 1-chloropyrene) were also detected (from 40 to 985 mg/kg), suggesting that the reaction of PAHs with disinfectant agents takes place in the coatings and not in the water phase after migration.
A simple, efficient matrix solid phase dispersive extraction (MSPD) method was optimised to analy... more A simple, efficient matrix solid phase dispersive extraction (MSPD) method was optimised to analyse simultaneously polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs) from sediments, and was compared to microwave-assisted extraction (MAE). New dispersing agents were tested to improve MSPD extraction. 3-chloropropyl-bonded silica particles, in addition to Florisil, increased significantly the polyaromatics desorption capacity. A compromise was found for eluting both families of compounds from sediments, using a small volume of hexane/acetone. Low procedural detection limits could be reached (0.06-0.22 ng g − 1 and 0.3-1.1 ng g − 1 for PAHs and PCBs, respectively). Mean total extraction recoveries were good for PAHs (>67%, depending on the sediment) and for PCBs (>89%), with good precision (6-9% and 4-10% inter-day precision for PAHs and PCBs, respectively). Higher recoveries for PCBs could be reached in comparison with formerly developed sonication or Soxhlet extraction methods, but also with MAE. MSPD offered significant decrease of sample amount, of solvent consumption and allowed more efficient cleaning of the sediment matrix, leading to less matrix effects compared to MAE, removing lots of interfering compounds without additional purification step. The robustness of the MSPD methodology could be demonstrated extracting quantitatively sediments from different sources and with various mineralogical characteristics.
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