References of "Thomé, Jean-Pierre"
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See detailAssociations of Plasma Concentrations of Dichlorodiphenyldichloroethylene and Polychlorinated Biphenyls with Prostate Cancer: A Case–Control Study in Guadeloupe (French West Indies)
Emeville, Elise; Giusti, Arnaud ULg; Coumoul, Xavier et al

in Environmental Health Perspectives (2015), 123(4), 317-323

Background: Long-term exposure to persistent pollutants with hormonal properties (endocrine-disrupting chemicals, EDCs) may contribute to the risk of prostate cancer (PCa). However, epidemiological ... [more ▼]

Background: Long-term exposure to persistent pollutants with hormonal properties (endocrine-disrupting chemicals, EDCs) may contribute to the risk of prostate cancer (PCa). However, epidemiological evidence remains limited. Objectives: We investigated the relationship between PCa and plasma concentrations of universally widespread pollutants, in particular p,p’- dichlorodiphenyl dichloroethene (DDE) and the non-dioxin like polychlorinated biphenyl congener 153 (PCB153). Methods and Findings: We evaluated before treatment 576 men with newly diagnosed PCa and 655 controls in Guadeloupe (French West Indies). Exposure was analyzed according to case-control status. Associations were assessed by unconditional logistic regression analysis, controlling for confounding factors. Missing data were handled by multiple imputation. We estimated a significant positive association between DDE and PCa (adjusted odds ratio [OR] 1.53; 95% CI 1.02, 2.30 for the highest versus lowest quintile of exposure; PTrend= 0.01). PCB153 was inversely associated with PCa (OR 0.30; 95% CI 0.19, 0.47 for the highest versus lowest quintile of exposure values; PTrend<0.001). Also, PCB153 was more strongly associated to low-grade than high grade PCa. Conclusions: Associations of PCa with DDE and PCB153 were in opposite directions. This may reflect differences in the mechanisms of action of these EDCs, and although our findings need to be replicated in other populations, they are consistent with complex effects of EDCs on human health. [less ▲]

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See detailSpatial variation in the concentrations of mercury and persistent organic pollutants in free-ranging bottlenose dolphins (Tursiops truncatus) from South Florida
Damseaux, France ULg; Kiszka, Jeremy; Heithaus et al

Poster (2014, December 12)

The bottlenose dolphin (Tursiops truncatus) is an abundant apex predator found in nearshore waters of South Florida, especially in the Lower Florida Keys (Key West) and the coastal waters of Everglades ... [more ▼]

The bottlenose dolphin (Tursiops truncatus) is an abundant apex predator found in nearshore waters of South Florida, especially in the Lower Florida Keys (Key West) and the coastal waters of Everglades National Park (ENP). The objective of this study was to assess variation in contamination levels of total mercury (T-Hg) and persistent organic pollutants (NDL-PCBs, PBDEs, DDT, HCH, HCB, PCDD/Fs and DL-PCBs) in bottlenose dolphins found offshore of the densely populated Key West (n = 27) and from undeveloped ENP (n = 20). T-Hg and POPs were analysed in skin and blubber, respectively, by the mean of Direct Mercury analyser (for THg), GC-ECD (POPs) and GC-HRMS (DLCs). The 7 ICES PCBs were the main compounds found in bottlenose dolphins from Key West (8229 ng.g-1 lipids) and the ENP (2289 ng.g-1 lipids), while the concentrations of PCDD/Fs remained low (Key West: 104 pg.g-1 lipids, ENP: 102 ng.g-1 lipids). POP concentrations were higher in individuals from Key West compared to those from the ENP. However, POPs concentrations in Key West dolphins were lower than those from other locations in Florida and around the world. Unlike organic pollutants, T-Hg concentrations were significantly higher in ENP dolphins (Key West: 2941 ng.g-1 dw versus ENP: 9314 ng.g-1 dw) highlighting the specific cycle of Hg in mangrove ecosystems. To conclude, sources of T-Hg and POPs differed between Key West and ENP as reflected by their concentrations in skin and blubber of free-ranging bottlenose dolphins highlighting their role as sentinels of their environment. [less ▲]

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See detailDietary early-life exposure to contaminated eels does not impair spatial cognitive performances in adult offspring mice as assessed in the Y-maze and the Morris water maze
Dridi, Imen; Leroy, Delphine; Guignard, Cedric et al

in Nutrition Research (2014), 34(12), 1075-1084

Many environmental contaminants are introduced via the diet and may act as neurotoxins and endocrine disrupters, especially influencing growing organisms in early life. The purpose of this study was to ... [more ▼]

Many environmental contaminants are introduced via the diet and may act as neurotoxins and endocrine disrupters, especially influencing growing organisms in early life. The purpose of this study was to examine whether dietary exposure of dams to fish naturally contaminated with xenobiotics, especially with polychlorinated biphenyls (PCBs) and heavy metals (e.g. mercury and lead), resulted in cognitive function deficits in adult offspring mice. Daily, four groups of dams (n = 10/group) ingested standard diet plus paste with/without eels, during gestation and lactation, from gestational day (GD) six until post natal day (PND) 21 (weaning). Dams orally ingested a standardized amount of eel (0.8 mgkg-1 d-1) containing the six non-dioxin-like (NDL) PCBs (σ6 NDL-PCBs: 28, 52, 101, 138, 153, and 180) at 0, 85, 216, and 400 ngkg-1 d-1. Results showed that early-life exposure to contaminated eels did not (compared to non-exposed controls) impair immediate working memory in the Y-maze in the offspring assessed at PND 38. Furthermore, it did not significantly impact spatial learning and retention memory as measured in the Morris water maze in adult offspring mice (PND 120-123). Our results suggest that perinatal exposure to contaminated eels does not affect spatial cognitive performances, as assessed by the Y-maze and Morris water maze at adult age. Adverse effects of xenobiotics reported earlier might be camouflaged by beneficial eel constituents, such as n-3 fatty acids. However, additional studies are needed to differentiate between potential positive and negative effects following consumption of food items both rich in nutrients and contaminants. © 2014 Elsevier Inc. [less ▲]

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See detailInvestigating apical adverse effects of four endocrine active substances in the freshwater gastropod Lymnaea stagnalis
Giusti, Arnaud ULg; Lagadic, Laurent; Barsi, Alpar et al

in Science of the Total Environment (2014), 493

The hermaphroditic gastropod Lymnaea stagnalis is proposed as a candidate species for the development of OECD guidelines for testing of the reprotoxicity of chemicals, including endocrine active ... [more ▼]

The hermaphroditic gastropod Lymnaea stagnalis is proposed as a candidate species for the development of OECD guidelines for testing of the reprotoxicity of chemicals, including endocrine active substances (EASs). Up to now, only a few putative EASs have been tested for their reproductive toxicity in this species. In this study, we investigate the effects of four EASs with different affinities to the vertebrate estrogen and androgen receptors (chlordecone as an estrogen; cyproterone acetate, fenitrothion and vinclozolin as anti-androgens) on the reproduction of L. stagnalis in a 21-day semi-static test. Testosterone and 17α-ethinylestradiol (EE2) were used as the reference compounds. The tested EASs had no significant effect on growth and survival at the tested concentration ranges (ng to μg/L). Classical reproduction endpoints (i.e., oviposition and fecundity) were not responsive to the tested chemicals, except for chlordecone and 17α-ethinylestradiol, which hampered reproduction from 19.6 μg/L and 17.6 μg/L, respectively. The frequency of polyembryonic eggs, used as an additional endpoint, demonstrated the effects of all compounds except EE2. The molecular pathways, which are involved in such reproduction impairments, remain unknown. Our results suggest that egg quality is a more sensitive endpoint as compared to other reproductive endpoints commonly assessed in mollusk toxicity tests. [less ▲]

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See detailMoult-related changes in the integument, midgut, and digestive gland in the freshwater amphipod gammarus pulex
Trevisan, Mélissa ULg; Leroy, Delphine; Decloux, Nicole ULg et al

in Journal of Crustacean Biology (2014), 34(5), 539-551

On the basis of macroscopic aspects (body and eye colour, lipid droplets), it was possible to sort specimens of Gammarus pulex (Linnaeus, 1758) into five categories that correspond to moult periods and ... [more ▼]

On the basis of macroscopic aspects (body and eye colour, lipid droplets), it was possible to sort specimens of Gammarus pulex (Linnaeus, 1758) into five categories that correspond to moult periods and stages (A, B, C, D1 and D2) based on integument features (tergite cuticle stiffness, layers and thickness). These stages also correspond to changes in digestive tract histology (gut content, cell ultrastructure, and lipid storage). With reference to the pereion tergite integument, this makes it possible to standardize moulting stage terminology and criteria with those applied to decapods while validating a quick, simple, moult-staging method that avoids injury and informs us about the physiology of the whole organism. The moult cycle was very short (about 12-15 days), with a "virtual," practically non-existent, anecdysis or "integument resting period" between post-ecdysis and pre-ecdysis. The pore canals previously known to be "open to the outside" appeared closed at early post-ecdysis by a lipid-rich fillng material that could be responsible for the cuticular waterproofing barrier allowing mineral deposition. In the digestive tract, the main structural changes were late post-ecdysial loss of midgut cells and digestive gland B-cells (probably by extrusion) when restarting the feeding cycle. Pre-ecdysial increase and post-ecdysial decrease in storage lipids are also obvious. We present a quick moult-staging method to sort a great number of G. pulex for physiological or toxicological assays investigating how animals at specific periods of their moult cycle respond to both natural and anthropogenic environmental changes. [less ▲]

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See detailBioaccumulation of polybrominated diphenyl ethers (PBDEs) in Gammarus pulex: Relative importance of different exposure routes and multipathway modeling
Lebrun, Jérémie; Leroy, Delphine; Giusti, Arnaud ULg et al

in Aquatic Toxicology (2014), 154

Characterizing the exposure routes of an organism and its ability to regulate accumulated contaminants is a crucial step toward developing a biomonitor. To date, very little data are available on the ... [more ▼]

Characterizing the exposure routes of an organism and its ability to regulate accumulated contaminants is a crucial step toward developing a biomonitor. To date, very little data are available on the bioaccumulation kinetics of PBDEs in freshwater biota. This study aims at investigating the potential use of a litter-degrader widely distributed in European freshwaters, Gammarus pulex, as an indicator of exposure to PBDEs. In aquatic microcosms, gammarids were exposed to a mixture of brominated congeners (BDE-28, 47, 66, 85, 99, 100, 153, 154 and 183) to assess their ability to bioconcentrate PBDEs. Results show that all tested congeners are highly internalized by G. pulex and uptake rates of PBDEs are closely related to their partition coefficients (Kow). The determination of the elimination rate of BDE-47, the congener most readily accumulated by gammarids, indicated that metabolism and excretion of this congener are low in G. pulex, which argues in favor of its use as a quantitative biomonitor. Finally, bioaccumulation experiments were performed using contaminated leaves to determine the relative importance of dietary uptake in the contamination of gammarids. Even though water is the preeminent exposure route, a significant uptake of BDE-47 through food was observed (27%). We propose a biodynamic model that takes into account both exposure routes to describe BDE-47 bioaccumulation. This study supports the use of this ubiquitous amphipod as an early warning monitor of the bioavailable contamination of freshwaters by PBDEs. [less ▲]

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See detailEffects of two PBDE congeners on the moulting enzymes of the freshwater amphipod Gammarus pulex.
Gismondi, Eric ULg; Thomé, Jean-Pierre ULg

Poster (2014, May)

Polybrominated diphenyl ethers (PBDEs) constitute a class of chemical compounds included to the composition of usual products such as plastics, textiles or electrical equipment, due to their flame ... [more ▼]

Polybrominated diphenyl ethers (PBDEs) constitute a class of chemical compounds included to the composition of usual products such as plastics, textiles or electrical equipment, due to their flame retardants properties. Since 2004, PBDEs were banned in Europe and listed as Priority Substances within the European Union Water Frame Work Directive. Unfortunately, the release of PBDEs always occurs in ecosystems due to their presence in products currently in use and new products manufactured using recycled PBDE-containing material. However, only few studies have investigated their impacts on freshwater invertebrates. This work aimed to study the effects of BDE-47 and BDE-99 congeners on the chitobiase and chitinolytic enzymes activities of the freshwater amphipod Gammarus pulex, according to gender, PBDE concentration and time of exposure. In addition, the bioaccumulation of BDE-47 and BDE-99 were measured. The results revealed that there was a dose-response relationship for the PBDE accumulation in G. pulex, whatever the gender and the PBDE congeners. Female G. pulex bioaccumulated more PBDE than males, and especially BDE-99 which was more accumulated than BDE-47. Moreover, PBDE exposures for 96hrs have caused the inhibition of chitobiase and chitinolytic enzymes activities. This study not only indicate the importance of taking into account various confounding factors (gender, congeners, concentration) to understand the PBDE effects, but underline also disruptions of enzymes activities involved in the molting process. These disturbances suggest effects on the gammarid development and reproduction, and consequently on the gammarid population. [less ▲]

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See detailEffects of two PBDE congeners on the moulting enzymes of the freshwater amphipod Gammarus pulex
Gismondi, Eric ULg; Thomé, Jean-Pierre ULg

in Environmental Pollution (2014), 191

Polybrominated diphenyl ethers (PBDEs) are abundant in aquatic environment. However, only few studies have investigated their impacts on freshwater invertebrates. This work aimed to study the effects of ... [more ▼]

Polybrominated diphenyl ethers (PBDEs) are abundant in aquatic environment. However, only few studies have investigated their impacts on freshwater invertebrates. This work aimed to study the effects of BDE-47 and BDE-99 congeners on the chitobiase and chitinolytic enzymes activities of the freshwater amphipod Gammarus pulex, according to gender, PBDE concentration and time of exposure. In addition, the bioaccumulation of BDE-47 and BDE-99 were measured. Results revealed that females have bioaccumulated more PBDE than males, and BDE-99 was more accumulated than BDE-47. PBDE exposures for 96hrs have caused chitobiase and chitinolytic enzymes inhibition. This study not only indicate the importance of taking into account various confounding factors (gender, congeners, concentration) to understand PBDE effects, but underline also disruptions of molting enzymes activities. These disturbances suggest effects on the gammarid development and reproduction, and consequently effects on the gammarid population, and on a larger scale, a dysfunction of the ecosystem. [less ▲]

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See detailFlore et faune de l'estran. Régions de Wimereux (Pas-de-Calais) et de Roscoff (Finistère)
Bussers, Jean-Claude ULg; Jeuniaux, Charles; Thomé, Jean-Pierre ULg et al

Learning material (2014)

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See detailProteomic Analysis of the Reproductive Organs of the Hermaphroditic Gastropod Lymnea stagnalis Exposed to Different Endocrine Disrupting Chemicals
Giusti, Arnaud ULg; Leprince, Pierre ULg; Mazzucchelli, Gabriel ULg et al

in PLoS ONE (2013), 8(11), 81086

Many studies have reported perturbations of mollusc reproduction following exposure to low concentrations (ng/L range) of endocrine disrupting chemicals (EDCs). However, the mechanisms of action of these ... [more ▼]

Many studies have reported perturbations of mollusc reproduction following exposure to low concentrations (ng/L range) of endocrine disrupting chemicals (EDCs). However, the mechanisms of action of these molecules on molluscs are still poorly understood. Investigation of the modifications of protein expression in organisms exposed to chemicals using proteomic methods can provide a broader and more comprehensive understanding of adverse impacts of pollution on organisms than conventional biochemical biomarkers (e.g., heat-shock proteins, metallothioneins, GST, EROD). In this study we have investigated the impacts of four chemicals, which exhibit different endocrine disrupting properties in vertebrates, on the proteome of the hermaphroditic freshwater pulmonate gastropod Lymnaea stagnalis after 21 days of exposure. Testosterone, tributyltin, chlordecone and cyproterone acetate were chosen as tested compounds as they can induce adverse effects on the reproduction of this snail. The 2D-DIGE method was used to identify proteins whose expression was affected by these compounds. In addition to modifying the expression of proteins involved in the structure and function of the cytoskeleton, chemicals had impacts on the expression of proteins involved in the reproduction of L. stagnalis. Exposure to 19.2 μg/L of chlordecone increased the abundance of ovipostatin, a peptide transmitted during mating through seminal fluid, which reduces oviposition in this species. The expression of yolk ferritin, the vitellogenin equivalent in L. stagnalis, was reduced after exposure to 94.2 ng Sn/L of tributyltin. The identification of yolk ferritin and the modification of its expression in snails exposed to chemicals were refined using western blot analysis. Our results showed that the tested compounds influenced the abundance of yolk ferritin in the reproductive organs. Alteration in proteins involved in reproductive pathways (e.g., ovipostatin and yolk ferritin) could constitute relevant evidence of interaction of EDCs with reproductive pathways that are under the control of the endocrine system of L. stagnalis. [less ▲]

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See detailImpact of anti-androgenic substances on gametogenesis of the rotifer Brachionus calyciflorus
Cruciani, Valentina ULg; Thomé, Jean-Pierre ULg; Joaquim-Justo, Célia ULg

Poster (2013, October 01)

Several studies have shown that pollutants with anti-androgenic activity have an impact on the sexual reproduction of the rotifer Brachionus calyciflorus (Joaquim-Justo et al., submit; Preston et al ... [more ▼]

Several studies have shown that pollutants with anti-androgenic activity have an impact on the sexual reproduction of the rotifer Brachionus calyciflorus (Joaquim-Justo et al., submit; Preston et al., 2001). The effects observed are compatible with the phenomenon of endocrine disruption. Fenitrothion, a non-steroidal anti-androgen induces a decrease in fertilization rate following exposure below or equal to 0,5 mg L-1.. The steroidal anti-androgen, cyproterone acetate increases number of cysts in population exposed to concentrations below or equal to 0,5 mg L-1. Cross mating experiments showed that effects of fenitrothion are due to an impact on males exclusively, while effects of cyproterone acetate exposition are due to an impact on females exclusively. In this study, we investigated the impact of fenitrothion on spermatogenesis and observed a decrease in the spermatozoa production and mobility with concentrations down to 0,5 mg L-1. We report a detailed description of the morphology of the male reproductive apparatus in B. calyciflorus based on optic, transmission electron and scanning electron microscopy in controls and exposed individuals. [less ▲]

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See detailReproductive impacts of tributyltin (TBT) and triphenyltin (TPT) in the hermaphroditic freshwater gastropod Lymnaea stagnalis
Giusti, Arnaud ULg; Barsi, Alpar; Dugué, Maël et al

in Environmental Toxicology & Chemistry (2013), 32(7), 1552-1560

Tributyltin (TBT) and triphenyltin (TPT) are emblematic endocrine disruptors, which have been mostly studied in gonochoric prosobranchs. Although both compounds can simultaneously occur in the environment ... [more ▼]

Tributyltin (TBT) and triphenyltin (TPT) are emblematic endocrine disruptors, which have been mostly studied in gonochoric prosobranchs. Although both compounds can simultaneously occur in the environment, they have mainly been tested separately for their effects on snail reproduction. Because large discrepancies in experimental conditions occurred in these tests, the present study aimed at comparing the relative toxicity of TBT and TPT under similar laboratory conditions in the 0–600 ng Sn/L range. Tests were performed on the simultaneous hermaphrodite Lymnaea stagnalis, a freshwater snail in which effects of TPT were unknown. Survival, shell length and reproduction were monitored in a 21d semi-static test. Frequency of abnormal eggs was assessed as an additional endpoint. TPT hampered survival while TBT did not. Major effects on shell solidity and reproduction were observed for both compounds, reproductive outputs being more severely hampered by TBT than by TPT. Considering the frequency of abnormal eggs allowed increasing test sensitivity, since snail responses to TBT could be detected at concentrations as low as 19 ng Sn/L. However, the putative mode of action of the two compounds could not be deduced from the structure of the molecules or from the response of apical endpoints. Sensitivity of L. stagnalis to TBT and TPT was compared to the sensitivity of prosobranch molluscs with different habitats and different reproductive strategies. [less ▲]

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