Éditeur(s) : HAL CCSD BioScientifica
Résumé : International audience
BACKGROUND: Differences in circulating steroid hormone levels have been hypothesized to explain ethnic differences in steroid-related diseases. The aim of this study was to determine the serum levels of a wide panel of steroid hormones, both androgens and estrogens, in healthy middle-aged African-Caribbean and European men. DESIGN AND METHODS: Serum steroid hormone levels were determined in men participating in a systematic public health study funded by the French National Health Insurance system. Blood was collected in the morning from 304 healthy African-Caribbean and European men aged between 40 and 69 years. Serum steroids were measured by mass spectrometry-gas chromatography, except for DHEAS and sex hormone-binding globulin, which were determined by RIA. Data were analyzed in 10-year age intervals by analysis of covariance, with adjustment for age, body mass index, waist-to-hip ratio, tobacco and alcohol consumption, and season of sampling. RESULTS: Compared with Europeans, African-Caribbean men presented significantly higher serum levels of measured bioavailable testosterone, 4-androstenedione (4-dione), and estrone (E1) regardless of the age group, of 5-androstenediol (5-diol) in those aged 40-49 and 50-59 years, and of testosterone (TT) and dihydrotestosterone in those aged 40-49 years. In contrast, European men aged 40-69 years showed significantly higher serum levels of DHEA and DHEAS. CONCLUSIONS: Significant differences in serum steroid hormone levels were observed in middle-aged African-Caribbean and European men. Whether such differences could contribute to ethnic differences in disease risk in adult men remains to be investigated. Some steroids, such as bioavailable TT, 4-dione, 5-diol, and E1, deserve particular attention.
ISSN: 0804-4643

hal-00876034
https://hal.archives-ouvertes.fr/hal-00876034
DOI : 10.1530/EJE-11-0551
PUBMED : 21951700

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The behaviour of the four Ra isotopes (measured by gamma spectrometry) and 222Rn (measured with an AlphaGUARD ionisation chamber) has been investigated in NaCl-rich thermal waters of Balaruc-les-Bains on the Mediterranean coast (South of France). This study allows identification of the deep thermal water signature and reveals the influence of seawater or karst water inflows on Ra isotopes and 222Rn. The deep thermal water has 226Ra and 222Rn activities of 840 and 1900 mBq/l, respectively, a (228Ra/226Ra) activity ratio of 0.59, and low (224Ra/228Ra) and (223Ra/226Ra) ratios of 0.67 and 0.025, respectively. Several arguments suggest a dominant role of radioactive decay for short-lived Ra isotopes and Rn during the relatively rapid ascent of thermal water through wide open fractures and drains. The low (223Ra/226Ra) ratio constrains the maximum ascent velocity of thermal water to 8-10 m/h. Seawater inflow into the hydrothermal system results in an enrichment in short-lived Ra isotopes and 222Rn. The high (223Ra/226Ra) ratio (0.23) suggests that 223Ra, 224Ra and 222Rn produced by alpha-recoil in the upper-Jurassic limestone are entrained by seawater percolation through the coastal basement, due to active pumping in one of the near shore production well. This process would be enhanced by a low water/rock ratio (i.e. in a low-porosity, micro-fractured limestone). Mixing of this enriched seawater with thermal water induces barite precipitation with co-precipitation of a large fraction of Ra. Short-lived Ra isotopes may thus be useful tracers of seawater flux towards the continent. Conversely, the inflow and mixing of karst groundwater result in a general dilution of all dissolved elements, only a small enrichment in 224Ra and 223Ra, but a large enrichment in 222Rn (up to 26 Bq/l). The combination of Ra isotopes and 222Rn data provides a good way to trace the dynamics of different water masses along coastal areas.
ISSN: 0016-7037

hal-00795512
https://hal.archives-ouvertes.fr/hal-00795512
DOI : 10.1016/j.gca.2012.09.010

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Diploid budding yeast undergoes rapid mitosis when it ferments glucose, and in the presence of a non-fermentable carbon source and the absence of a nitrogen source it triggers sporulation. Rich medium with acetate is a commonly used pre-sporulation medium, but our understanding of the molecular events underlying the acetate-driven transition from mitosis to meiosis is still incomplete. We identified 263 proteins for which mRNA and protein synthesis are linked or uncoupled in fermenting and respiring cells. Using motif predictions, interaction data and RNA profiling we find among them 28 likely targets for Ume6, a subunit of the conserved Rpd3/Sin3 histone deacetylase-complex regulating genes involved in metabolism, stress response and meiosis. Finally, we identify 14 genes for which both RNA and proteins are detected exclusively in respiring cells but not in fermenting cells in our sample set, including CSM4, SPR1, SPS4 and RIM4, which were thought to be meiosis-specific. Our work reveals intertwined transcriptional and post-transcriptional control mechanisms acting when a MATa/α strain responds to nutritional signals, and provides molecular clues how the carbon source primes yeast cells for entering meiosis. Our integrated genomics study provides insight into the interplay between the transcriptome and the proteome in diploid yeast cells undergoing vegetative growth in the presence of glucose (fermentation) or acetate (respiration). Furthermore, it reveals novel target genes involved in these processes for Ume6, the DNA binding subunit of the conserved histone deacetylase Rpd3 and the co-repressor Sin3. We have combined data from an RNA profiling experiment using tiling arrays that cover the entire yeast genome, and a large-scale protein detection analysis based on mass spectrometry in diploid MATa/α cells. This distinguishes our study from most others in the field-which investigate haploid yeast strains-because only diploid cells can undergo meiotic development in the simultaneous absence of a non-fermentable carbon source and nitrogen. Indeed, we report molecular clues how respiration of acetate might prime diploid cells for efficient spore formation, a phenomenon that is well known but poorly understood.
ISSN: 1874-3919

hal-01122122
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122122
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122122/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122122/file/Integrated%20RNA-%20and%20protein%20profiling%20of%20fermentation.pdf
DOI : 10.1016/j.jprot.2015.01.015

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
ABSTRACT: BACKGROUND: The amount of lead in the environment has decreased significantly in recent years, and so did exposure. However, there is no known safe exposure level and, therefore, the exposure of children to lead, although low, remains a major public health issue. With the lower levels of exposure, it is becoming more difficult to identify lead sources and new approaches may be required for preventive action. This study assessed the usefulness of lead isotope ratios for identifying sources of lead using data from a nationwide sample of French children aged from six months to six years with blood lead levels (B-Pb) [greater than or equal to] 25 ug/L. METHODS: Blood samples were taken from 125 children, representing about 600,000 French children; environmental samples were taken from their homes and personal information was collected. Lead isotope ratios were determined using quadrupole ICP-MS (inductively coupled plasma - mass spectrometry) and the isotopic signatures of potential sources of exposure were matched with those of blood in order to identify the most likely sources. RESULTS: In addition to the interpretation of lead concentrations, lead isotope ratios were potentially of use for 57% of children aged from six months to six years with blood lead level [greater than or equal to] 25 ug/L (7% of overall children in France, about 332,000 children), with at least one potential source of lead and sufficiently well discriminated lead isotope ratios. Lead isotope ratios revealed a single suspected source of exposure for 32% of the subjects and were able to eliminate at least one unlikely source of exposure for 30% of the children. CONCLUSIONS: In France, lead isotope ratios could provide valuable additional information in about a third of routine environmental investigations.
ISSN: 1476-069X

inserm-00624817
http://www.hal.inserm.fr/inserm-00624817
http://www.hal.inserm.fr/inserm-00624817/document
http://www.hal.inserm.fr/inserm-00624817/file/1476-069X-10-75.pdf
DOI : 10.1186/1476-069X-10-75

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
ISSN: 0098-0331

hal-01083748
https://hal-agroparistech.archives-ouvertes.fr/hal-01083748
DOI : 10.1007/s10886-009-9673-x

Éditeur(s) : HAL CCSD IWA Publishing
Résumé : International audience
Anti-cancer drugs are an important class of pharmaceutical products. Methotrexate (MTX) is a folic acid antagonist used in high doses as antimetabolite in anti-cancer treatment as well as in low doses for the treatment of rheumatoid arthritis and adults' psoriasis. In the past, several anti-cancer drugs, including methotrexate, have been found in the environment. Their presence in water, especially if used for the production of drinking water, is even in low concentrations of particular interest, due to the risk to retrieve them in the consumed water and their high activity and grave effects. But prior to usage as drinking water, raw waters are treated and chlorination is a common practice in several countries. As such a treatment can lead to the formation of organochlorine in water, the study of the fate of MTX during chlorination in a batch trial was carried out. The reaction was monitored by dissolved organic carbon (DOC) and by fluorescence and UV spectroscopy. Investigation of by-products formed was done with liquid chromatography/mass spectrometry (LC/MS). Under the given experimental conditions, Methotrexate was eliminated rapidly (t1/2 around 21 min). However, DOC elimination was incomplete. Monitoring with LC-MS showed the formation of a monochlorinated transformation product of MTX. In silico analysis of the proposed transformation products for different carcinogenic, mutagenic and genotoxic endpoints with different software platforms provided no clear evidence that the possible transformation products after chlorination might be more toxic than the parent compound. However, since a number of alerts is altered after chlorination, it cannot be excluded that the toxicity of these transformation products might be modulated compared with the parent compound.
ISSN: 0043-1354

hal-01016617
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01016617
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01016617/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01016617/file/Monitoringsur methotrexate_final.pdf
DOI : 10.1016/j.watres.2014.03.008

Éditeur(s) : HAL CCSD
Résumé : The presence of obstacles met in natural environment by the flow, influences the dispersion of air pollutants which it carries. This thesis, based on spatiotemporal micro-meteorological measurements in tropical region, aims at studying the dispersion of compounds emitted by the ecosystem mangrove according to the weather conditions. At a daily scale, the meteorological analysis reveals, besides the presence of Trade Winds, the existence of thermal flows of which nocturnal thermodynamic parameters have been defined. The field observation has shown that the weak intensity of the wind disadvantages the dispersion of compounds emitted during the night. At a finer scale, the existence of a spectral gap separating large scale phenomena of those related to turbulence has been demonstrated. These last ones were treated by spectral and statistical approaches to quantify the turbulent fluxes of momentum and sensible heat during the night, for an averaged duration of 13 minutes. The stratification of the surface layer has been considered and determined by Monin-Obukhov similarity theory. The measurements acquired at night and the application of Kolmogorov theory allowed us to deduct the dissipation rate of energy and the size of the vortices at 5.5 meters in height. This work has also led us, by gas chromatography coupled to mass spectrometry, to identify, in mangrove, sulphurated volatil organic compounds, organohalogen, BTEX, ... All these results will later serve to feed dispersion models related to the studied ecosystem.
La présence d'obstacles rencontrés en milieu naturel par l'écoulement, influence la dispersion des polluants qu'il transporte. Cette thèse, fondée sur des mesures micro-météorologiques spatio-temporelles en région tropicale, vise à étudier la dispersion de composés émis par l'écosystème mangrove en fonction des conditions météorologiques. A l'échelle journalière, l'analyse météorologique révèle, outre la présence des Alizés, l'existence d'écoulements thermiques dont des paramètres thermodynamiques nocturnes ont été définis. L'observation terrain nous a montré que la faible intensité du vent défavorise la dispersion des composés émis durant la nuit. A une échelle plus fine, l'existence d'un trou spectral séparant les phénomènes de grande échelle de ceux liés à la turbulence a été mise en évidence. Ces derniers ont été traités par des approches spectrale et statistique pour quantifier les flux turbulents de quantité de mouvement et de chaleur sensible, pendant la nuit, pour une durée de moyenne de l'ordre de 13 minutes. L'état de stratification de la couche de surface a été pris en compte et déterminé par la théorie de similitude de Monin-Obukhov. Les mesures nocturnes effectuées et l'application de la théorie de Kolmogorov ont permis de déduire les taux de dissipation de l'énergie et la taille des tourbillons à 5,5 m d'altitude. Ce travail a également conduit, par l'analyse chromatographique en phase gazeuse couplée à la spectrométrie de masse, à l'identification, en mangrove, de composés organiques volatils soufrés, des organohalogénés, des BTEX, ... L'ensemble de ces résultats servira ultérieurement à alimenter les modèles de dispersion spécifiques liés aux écosystèmes étudiés.
https://tel.archives-ouvertes.fr/tel-00665882

Droits : info:eu-repo/semantics/OpenAccess
NNT : 11AGUY0438
tel-00665882
https://tel.archives-ouvertes.fr/tel-00665882
https://tel.archives-ouvertes.fr/tel-00665882/document
https://tel.archives-ouvertes.fr/tel-00665882/file/ThA_seCdAlexis.pdf

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Mantle cell lymphoma (MCL) is a hematologic neoplasm characterised by the t(11;14)(q13;q32) translocation leading to aberrant cyclin D1 expression. The cell functions of cyclin D1 depend on its partners and/or subcellular distribution, resulting in different oncogenic properties. We observed the accumulation of cyclin D1 in the cytoplasm of a subset of MCL cell lines and primary cells. In primary cells, this cytoplasmic distribution was correlated with a more frequent blastoid phenotype. We performed immunoprecipitation assays and mass spectrometry on enriched cytosolic fractions from two cell lines. The cyclin D1 interactome was found to include several factors involved in adhesion, migration and invasion. We found that the accumulation of cyclin D1 in the cytoplasm was associated with higher levels of migration and invasiveness. We also showed that MCL cells with high cytoplasmic levels of cyclin D1 engrafted more rapidly into the bone marrow, spleen, and brain in immunodeficient mice. Both migration and invasion processes, both in vivo and in vitro, were counteracted by the exportin 1 inhibitor KPT-330, which retains cyclin D1 in the nucleus. Our data reveal a role of cytoplasmic cyclin D1 in the control of MCL cell migration and invasion, and as a true operator of MCL pathogenesis.
ISSN: 2045-2322

hal-01635754
https://hal.archives-ouvertes.fr/hal-01635754
DOI : 10.1038/s41598-017-14222-1
PUBMED : 29066743

Éditeur(s) : HAL CCSD Wiley Open Access
Résumé : International audience
Plant responses to natural enemies include formation of secondary metabolites acting as direct or indirect defenses. Volatile terpenes represent one of the most diverse groups of secondary metabolites. We aimed to explore evolutionary patterns of volatile terpene emission. We measured the composition of damage-induced volatile terpenes from 202 Amazonian tree species, spanning the angiosperm phylogeny. Volatile terpenes were extracted with solid-phase micro extraction and desorbed in a gas chromatography–mass spectrometry for compound identification. The chemical diversity of the terpene blend showed a strong phylogenetic signal as closely related species emitted a similar number of compounds. Closely related species also tended to have compositionally similar blends, although this relationship was weak. Meanwhile, the ability to emit a given compound showed no significant phylogenetic signal for 200 of 286 compounds, indicating a high rate of diversification in terpene synthesis and/or great variability in their expression. Three lineages (Magnoliales, Laurales, and Sapindales) showed exceptionally high rates of terpene diversification. Of the 70 compounds found in >10% of their species, 69 displayed significant correlated evolution with at least one other compound. These results provide insights into the complex evolutionary history of volatile terpenes in angiosperms, while highlighting the need for further research into this important class of compounds.
ISSN: 2045-7758

Droits : http://creativecommons.org/licenses/by/
hal-01296640
http://hal.upmc.fr/hal-01296640
http://hal.upmc.fr/hal-01296640/document
http://hal.upmc.fr/hal-01296640/file/ece31810.pdf
DOI : 10.1002/ece3.1810

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
CP12 is a small chloroplast protein involved in the Benson-Calvin cycle. Since it was demonstrated that the CP12 protein shared different conformational properties between reduced and oxidized states we took advantage of the segregational properties of the Traveling Wave Ion Mobility (TWIM) guide to study subtle conformational changes related to redox changes. Electrospray ionization mass (ESI-MS) spectra of the CP12 protein were recorded in the positive ion mode using an ESI source fitted on a quadrupole time-of-flight (QToF) hybrid mass spectrometer equipped with a TWIM cell (Synapt HDMS G1, Waters Corp., Manchester) under non-denaturing conditions. Non-covalent experiments were performed using the same instrument without the use of the TWIM device. Whatever the CP12 form studied, our results showed that CP12 protein was represented by two conformers in equilibrium that displayed very slight differences. These observations led us to propose that CP12 protein structure is rather undergoing transient subtle structural changes than having two different conformational populations in solution. In addition, using non-denaturing experiments, NAD and CP12 stoichiometry were determined with respect to the GAPDH tetramer and the redox state of CP12. In this study we showed that the use of the segregational property of the ion mobility (TWIM, Synapt G1 HDMS, Waters, Manchester, UK) allowed differentiation of subtle conformational changes between redox states of the CP12 protein. Standard non-denaturing experiments revealed different binding stoichiometry according to the redox state of the CP12 protein.
ISSN: 0951-4198

hal-01122181
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122181
DOI : 10.1002/rcm.6442
PUBMED : 23239332

Éditeur(s) : HAL CCSD Mineralogical Society of America
Résumé : International audience
Wadsleyites with various iron contents were synthesized at ~12-14 GPa and 1400 °C under oxidizing and hydrous conditions in coexistence with enstatite. The samples were studied using micro-X-ray absorption near edge structure (XANES) and micro-Mössbauer spectroscopy to determine the ferric iron contents in polyphasic samples and secondary ion mass spectrometry (SIMS) to determine the water concentrations. XANES and Mössbauer analyses show that ferric iron content increases with increasing total iron content, and reaches a maximum of ~30% Fe3+/Fetotal. Two XANES results were cross-checked by Mössbauer analysis and both methods are in reasonable agreement. The use of Fourier transform infrared spectroscopy reveals a new protonation scheme in wadsleyite, with a significant proportion of protons associated with the high-frequency band at 3611 cm−1 and a new band located at 3500 cm−1. The intensity of these two bands is higher for Fe3+-rich wadsleyite. SIMS analyses show that water contents in wadsleyite vary from 4500 to 9400 ppm H2O by weight. Pyroxene water contents range from 790 to 1600 ppm wt H2O. The concentration of water in both phases decreases with increasing iron content. The partition coefficient of water between wadsleyite and pyroxene varies between 5 and 9 and increases with increasing Fe-number of wadsleyite [i.e., XFe/(XFe + XMg) × 100 ratio]. The divalent cation concentrations (i.e., Mg2+ + Fe2+), the Si as well as the H content in wadsleyite decrease with increasing Fe3+ content, indicating an incorporation mechanism via substitution into the metal (Me = Mg2+ and Fe2+) and Si sites with a ratio of 5/3 for (Fe3++H+):Me and of 5/1 for (Fe3++H+):Si, similarly as in the dry system. Thus, coupled substitution of Fe3+ and H+ does not affect the incorporation mechanism of Fe3+, but does affect the location of H+, which is partly incorporated at tetrahedral edges forming [FeSi′-(OH)o*]X neutral defects substituting for Si. In this model 25% of the ferric iron occupies the tetrahedral sites.
ISSN: 0003-004X

hal-00758071
https://hal.archives-ouvertes.fr/hal-00758071
DOI : 10.2138/am.2012.3869

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Saccharomyces cerevisiae is an established model organism for the molecular analysis of fundamental biological processes. The genomes of numerous strains have been sequenced, and the transcriptome and proteome ofmajor phases during the haploid and diploid yeast life cycle have been determined. However, much less is known about dynamic changes of the proteome when cells switch from mitotic growth to meiotic development. We report a quantitative protein profiling analysis of yeast cell division and differentiation based on mass spectrometry. Information about protein levels was integrated with strand-specific tiling array expression data. We identified a total of 2366 proteins in at least one condition, including 175 proteins showing a statistically significant > 5-fold change across the sample set, and 136 proteins detectable in sporulating but not respiring cells. We correlate protein expression patterns with biological processes and molecular function by Gene Ontology term enrichment, chemoprofiling, transcription interference and the formation of double stranded RNAs by overlapping sense/antisense transcripts. Our work provides initial quantitative insight into protein expression in diploid respiring and differentiating yeast cells. Critically, it associates developmentally regulated induction of antisense long noncoding RNAs and double stranded RNAs with fluctuating protein concentrations during growth and development.
ISSN: 1874-3919

hal-01485858
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01485858
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01485858/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01485858/file/Becker%20et%20al.%20-%20The%20protein%20expression%20landscape%20of%20mitosis%20and%20me.pdf
DOI : 10.1016/j.jprot.2016.12.016

Éditeur(s) : HAL CCSD American Chemical Society
Résumé : International audience
The present study is a contribution to the "neXt50 challenge", a coordinated effort across C-HPP teams to identify the SO most tractable missing proteins (MPs) on each chromosome. We report the targeted search of 38 theoretically detectable MPs from chromosomes 2 and 14 in Triton X-100 soluble and insoluble sperm fractions from a total of 15 healthy donors. A targeted mass spectrometry-based strategy consisting of the development of LC-PRM assays (with heavy labeled synthetic peptides) targeting 92 proteotypic peptides of the 38 selected MPs was used. Out of the 38 selected MPs, 12 were identified with two or more peptides and 3 with one peptide after extensive SDS-PAGE fractionation of the two samples and with overall low-intensity signals. The PRM data are available via ProteomeXchange in PASSEL (PASS01013). Further validation by immunohistochemistry on human testes sections and cytochemistry on sperm smears was performed for eight MPs with antibodies available from the Human Protein Atlas. Deep analysis of human sperm still allows the validation of MPs and therefore contributes to the C-HPP worldwide effort. We anticipate that our results will be of interest to the reproductive biology community because an in-depth analysis of these MPs may identify potential new candidates in the context of human idiopathic infertilities.
ISSN: 1535-3893

hal-01681656
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01681656
DOI : 10.1021/acs.jproteome.7b00374

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The outer membrane proteins (OMPs) of Gram-negative bacteria play a crucial role in virulence and pathogenesis. Identification of these proteins represents an important goal for bacterial proteomics, because it aids in vaccine development. Here, we have developed such an approach for Ehrlichia ruminantium, the obligate intracellular bacterium that causes heartwater. A preliminary whole proteome analysis of elementary bodies, the extracellular infectious form of the bacterium, had been performed previously, but information is limited about OMPs in this organism and about their role in the protective immune response. Identification of OMPs is also essential for understanding Ehrlichia’s OM architecture, and how the bacterium interacts with the host cell environment. First, we developed an OMP extraction method using the ionic detergent sarkosyl, which enriched the OM fraction. Second, proteins were separated via one-dimensional electrophoresis, and digested peptides were analyzed via nano-liquid chromatographic separation coupled with mass spectrometry (LCMALDI-TOF/TOF). Of 46 unique proteins identified in the OM fraction, 18 (39%) were OMPs, including 8 proteins involved in cell structure and biogenesis, 4 in transport/virulence, 1 porin, and 5 proteins of unknown function. These experimental data were compared to the predicted subcellular localization of the entire E. ruminantium proteome, using three different algorithms. This work represents the most complete proteome characterization of the OM fraction in Ehrlichia spp. The study indicates that suitable subcellular fractionation experiments combined with straightforward computational analysis approaches are powerful for determining the predominant subcellular localization of the experimentally observed proteins.We identified proteins potentially involved in E. ruminantium athogenesis, which are good novel targets for candidate vaccines. Thus, combining bioinformatics and proteomics, we discovered new OMPs for E. ruminantium that are valuable data for those investigating new vaccines against this organism. In summary, we provide both pioneering data and novel insights into the pathogenesis of this obligate intracellular bacterium.
ISSN: 1932-6203

hal-01203402
https://hal.univ-antilles.fr/hal-01203402
https://hal.univ-antilles.fr/hal-01203402/document
https://hal.univ-antilles.fr/hal-01203402/file/2015_Moumene_PLOSONE-1.pdf
DOI : 10.1371/journal.pone.0116758

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
In addition to dietary exposure, children are exposed to metals via ingestion of soils and indoor dust, contaminated by natural or anthropogenic outdoor and indoor sources. The objective of this nationwide study was to assess metal contamination of soils and dust which young French children are exposed to. A sample of 484 children (6 months to 6 years) was constituted in order to obtain representative results for young French children. In each home indoor settled dust was sampled by a wipe in up to five rooms. Outdoor playgrounds were sampled with a soil sample ring (n=315) or with a wipe in case of hard surfaces (n=53). As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V were measured because of their potential health concern due to soil and dust ingestion. The samples were digested with hydrochloric acid, and afterwards aqua regia in order to determine both leachable and total metal concentrations and loadings by mass spectrometry with a quadrupole ICP-MS. In indoor settled dust most (total) loadings were below the Limit of Quantification (LOQ), except for Pb and Sr, whose median loadings were respectively 9 and 10 μg/m². The 95th percentile of loadings were 2 μg/m² for As, <0.8 for Cd, 18 for Cr, 49 for Cu, <64 for Mn, 63 for Pb, 2 for Sb, 56 for Sr, and <8 for V. Median/95th percentile of loadings in settled dust on outdoor playgrounds were 2/16, <0.8/1.3, 17/53, 49/330, 99/424, 32/393, 2/13, 86/661 and 10/37 μg/m² for As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V respectively. In outdoor playground soil median/95th percentile of concentrations (μg/g) were 8/26, <0.65/1, 25/52, <26/53,391/956, 27/254, 0.7/4, 54/295, 23/57 for As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V respectively. These results are comparable with those observed in other countries. Because of their representative nature, we can assess children's exposures to these metals via soil and dust and the associated risks in urban and rural environments. Ratios of leachable/total concentrations and loadings, calculated on >LOQ measurements, differed among metals. To a lesser extent, they were also affected by type of matrix, with (except for Cd) a greater leachability of dust (especially indoor) compared to soils.
ISSN: 0160-4120

hal-00732136
https://hal.archives-ouvertes.fr/hal-00732136
PUBMED : 22613504
DOI : 10.1016/j.envint.2012.04.010

Éditeur(s) : HAL CCSD Royal Society of Chemistry
Résumé : International audience
LA-ICP-MS analysis of the chemical composition of biogenic carbonate has many applications in the environmental sciences but the characteristics of the material produced by the ablation process are largely unknown. To fill this gap, we have undertaken a study of the chemical and physical nature of particles produced by laser ablation of biogenic carbonates. SEM imaging suggests that laser ablation produces two distinct particle populations, one consisting of microsize particles and the other of nanosize particles. A 213 nm laser gives rise to a higher proportion of microsize particles than a 193 nm laser, probably because the 213 nm laser couples less completely with carbonate material. The microsize particles appear to form by photomechanical fracturing along lines of cleavage or weakness, rather than by hydrodynamic sputtering (as is generally observed for silicates). Chemical analysis of the carbonate particles suggests that little chemical fractionation of biogenic carbonates occurs during the ablation process or during transport to the plasma. This is supported by the constancy of the fractionation factor ([X/Ca](measured)/[X/Ca] true) during the course of an ablation of a carbonate standard. In contrast, changes in the fractionation factor during the first few seconds of ablation of the NIST 612 are observed for some elements. This difference in fractionation is likely to result from the different formation mechanisms of the microsize particles.
ISSN: 0267-9477

hal-00411933
https://hal.archives-ouvertes.fr/hal-00411933
DOI : 10.1039/b706727e

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Despite the dramatic reductions in children's blood lead levels (BLLs), there is considerable evidence that low-level lead exposure is associated with intellectual deficits and behavioral problems, without apparent threshold. There are limited data, however, about the contribution of residential sources of lead to contemporary children's blood lead levels. The aim of this study is to calculate the contributions of residential sources of lead to assess the potential impact of setting new standards for lead levels in residential dust, soil and water. We enrolled 484 French children aged from 6 months to 6 years, and collected data on social, housing and individual characteristics. Lead concentrations in blood and environmental samples (water, soils, and dusts) were measured using inductively coupled plasma mass spectrometry. Data were analyzed using a multivariate generalized additive model accounting for the sampling design and the sampling weights. We found that exceedingly low concentrations of lead in dust, soil and water were significant predictors of children's BLLs, after adjustment for potential confounding variables. Lead-contaminated floor dust was the main source of lead in blood. BLLs (GM: 14μg/L) increased by 65%, 13%, 25%, and 5% when lead content in floor dust, loose soil, hard soil and water increased from their 25th percentile to their 95th percentile, respectively. We also observed that the steepest increase in BLLs occurred at the lowest levels of lead-contaminated floor dust, which indicates that lead contamination should be kept as low as possible. Impact of different possible standards on children's BLLs was also tabulated and indicated that unless standards are set low, they will only benefit a small proportion of children who have the highest exposures.
ISSN: 1438-4639

inserm-00821999
http://www.hal.inserm.fr/inserm-00821999
DOI : 10.1016/j.ijheh.2013.02.007
PUBMED : 23528234

Éditeur(s) : HAL CCSD Portland Press
Résumé : International audience
CP12 is a small chloroplastic protein involved in the Calvin cycle that was shown to bind copper, a metal ion involved in modulation of its transition from reduced to oxidized state. In order to describe CP12 copper binding properties, copper-IMAC experiments and site-directed mutagenesis based on computational modeling, were coupled to top-down mass spectrometry (ESI-MS and MSMS). Copper-IMAC experiments allowed the primary characterization of mutation effects upon copper binding. Top-down MSMS experiments carried out under non-denaturing conditions on wild-type and mutant CP12/Cu2+ complexes then allowed fragment ions specifically liganding the copper ion to be determined. Comparison of MSMS datasets defined three regions involved in metal ion binding: residues D16 to D23, D38 to K50 and D70 to E76, with the two first regions containing selected residues for mutation. These data confirmed that copper ligands involved glutamic and aspartic residues in contrast to typical protein copper chelators. We propose that copper might play a role in regulation of CP12 biological activity.
ISSN: 0264-6021

hal-00479106
https://hal.archives-ouvertes.fr/hal-00479106
https://hal.archives-ouvertes.fr/hal-00479106/document
https://hal.archives-ouvertes.fr/hal-00479106/file/PEER_stage2_10.1042%252FBJ20082004.pdf
DOI : 10.1042/BJ20082004

Éditeur(s) : HAL CCSD Taylor & Francis
Résumé : International audience
Humans may be exposed via their environment to multiple chemicals as a consequence of human activities and use of synthetic products. Little knowledge is routinely generated on the hazards of these chemical mixtures. The metabolomic approach is widely used to identify metabolic pathways modified by diseases, drugs, or exposures to toxicants. This review, based on the state of the art of the current applications of metabolomics in environmental health, attempts to determine whether metabolomics might constitute an original approach to the study of associations between multiple, low-dose environmental exposures in humans. Studying the biochemical consequences of complex environmental exposures is a challenge demanding the development of careful experimental and epidemiological designs, in order to take into account possible confounders associated with the high level of interindividual variability induced by different lifestyles. The choices of populations studied, sampling and storage procedures, statistical tools used, and system biology need to be considered. Suggestions for improved experimental and epidemiological designs are described. Evidence indicates that metabolomics may be a powerful tool in environmental health in the identification of both complex exposure biomarkers directly in human populations and modified metabolic pathways, in an attempt to improve understanding the underlying environmental causes of diseases. Nevertheless, the validity of biomarkers and relevancy of animal-to-human extrapolation remain key challenges that need to be properly explored.
ISSN: 1093-7404

hal-00976116
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00976116
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00976116/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00976116/file/Potential_input_from_metabolomics_accepted.pdf
DOI : 10.1080/10937404.2013.860318

Éditeur(s) : HAL CCSD MDPI
Résumé : International audience
Lead in childhood is well known to be associated with poor neurodevelopment. As part of a study on maternal anemia and offspring neurodevelopment, we analyzed blood lead level (BLL) with no prior knowledge of lead exposure in 225 mothers and 685 offspring 1 to 2 years old from Allada, a semi-rural area in Benin, sub-Saharan Africa, between May 2011 and May 2013. Blood samples were analyzed by inductively coupled plasma mass spectrometry. Environmental assessments in households and isotopic ratio measurements were performed for eight children with BLL extgreater 100 µg/L. High lead levels (BLL extgreater 50 µg/L) were found in 44% of mothers and 58% of children. The median BLL was 55.1 (interquartile range 39.2-85.0) and 46.6 (36.5-60.1) µg/L, respectively. Maternal BLL was associated with offspring's consumption of piped water and animals killed by ammunition. Children's BLL was associated with presence of paint chips in the house and consumption of animals killed by ammunition. In this population, with 98% of children still breastfed, children's BLL was highly associated with maternal BLL on multivariate analyses. Environmental measures and isotopic ratios supported these findings. Offspring may be highly exposed to lead in utero and probably via breastfeeding in addition to lead paint exposure
ISSN: 1660-4601

hal-01296778
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01296778
DOI : 10.3390/ijerph13030316
PUBMED : 26978384