References of "Thomé, Jean-Pierre"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailGroundwater quality assessment of one former industrial site in Belgium using a TRIAD-like approach.
Crévecoeur, Sophie; Debacker, Virginie ULg; Joaquim-Justo, Célia ULg et al

in Environmental Pollution (2011), 159(10), 2461-2466

Contaminated industrial sites are important sources of pollution and may result in ecotoxicological effects on terrestrial, aquatic and groundwater ecosystems. An effect-based approach to evaluate and ... [more ▼]

Contaminated industrial sites are important sources of pollution and may result in ecotoxicological effects on terrestrial, aquatic and groundwater ecosystems. An effect-based approach to evaluate and assess pollution-induced degradation due to contaminated groundwater was carried out in this study. The new concept, referred to as “Groundwater Quality TRIAD-like” (GwQT) approach, is adapted from classical TRIAD approaches. GwQT is based on measurements of chemical concentrations, laboratory toxicity tests and physico-chemical analyses. These components are combined in the GwQT using qualitative and quantitative (using zero to one subindices)integration approaches. The TRIAD approach is applied for the first time on groundwater from one former industrial site located in Belgium. This approach will allow the classification of sites into categories according to the degree of contaminant-induced degradation. This new concept is a starting point for groundwater characterization and is open for improvement and adjustment. [less ▲]

Detailed reference viewed: 45 (15 ULg)
Peer Reviewed
See detailThyroid hormone disrupting chemicals in sea bass (Dicentrarchus labrax) from European coasts
Schnitzler, Joseph ULg; Michel, Loïc ULg; Klaren, Peter et al

Conference (2011, February 25)

Polychlorinated biphenyls (PCBs) and organochlorine pesticides like Dichloro-Diphenyl-Trichloroethane (DDTs), Hexachlorocyclohexanes (HCHs), aldrin, dieldrin and trace elements (Cd, Cu, Se, Pb, Zn and Hg ... [more ▼]

Polychlorinated biphenyls (PCBs) and organochlorine pesticides like Dichloro-Diphenyl-Trichloroethane (DDTs), Hexachlorocyclohexanes (HCHs), aldrin, dieldrin and trace elements (Cd, Cu, Se, Pb, Zn and Hg) were analysed in the muscle of sea bass (Dicentrarchus labrax) sampled in coastal regions near several important European river mouths (Gironde, Charente, Loire, Seine and Scheldt). These potential endocrine disrupting chemicals were present in European coastal waters. Even if their concentrations were well below the Maximum Residue Limits set by the governments, they induced alterations of the endocrine system. We established correlations between contaminant concentrations and effects on the thyroid system in sea bass. The contaminants induced modifications of the metabolic pathways of thyroid hormones and enhanced thyroid hormone synthesis. The activity of T4 Outer Ring Deiodinase was increased, that leads to an intensified conversion of thyroxine (T4) to its more biologically active form triiodothyronine (T3). Meanwhile, the activity of T4 sulfatation was reduced, that leads to a lowered biliary excretion of thyroid hormones. The modified metabolic pathways of the thyroid hormones can be interpreted as a tool to homeostatically maintain the thyroid hormone status. Of all tested compounds, the higher chlorinated PCBs seemed to be the most implicated in this perturbation. The nature of thyroid hormone synthesis, signalling and regulation is highly conserved among vertebrates. Although we cannot extrapolate thyroid toxicity data directly from one species to another, these environmental factors may well affect thyroid function in other species, including humans. [less ▲]

Detailed reference viewed: 47 (4 ULg)
Full Text
Peer Reviewed
See detailOrganochlorine pesticides, polychlorinated biphenyls and trace elements in wild European sea bass (Dicentrarchus labrax) off European estuaries
Schnitzler, Joseph ULg; Thomé, Jean-Pierre ULg; Lepage, Mario et al

in Science of the Total Environment (2011), 409(19), 3680-3686

Polychlorinated biphenyls (PCBs) and organochlorine pesticides like dichloro-diphenyl-trichloroethane (DDTs), hexachlorocyclohexanes (HCHs), aldrin, dieldrin and trace elements (Cd, Cu, Se, Pb, Zn and Hg ... [more ▼]

Polychlorinated biphenyls (PCBs) and organochlorine pesticides like dichloro-diphenyl-trichloroethane (DDTs), hexachlorocyclohexanes (HCHs), aldrin, dieldrin and trace elements (Cd, Cu, Se, Pb, Zn and Hg) were analysed in the muscle of European sea bass (Dicentrarchus labrax) sampled in Atlantic coastal regions near several important European river mouths (Gironde, Charente, Loire, Seine and Scheldt). High contamination levels were measured in the muscles of European sea bass sampled in the coastal regions near those river mouths (e.g. Σ ICES PCB=133–10,478 μg kg−1 lw and Hg=250–2000 μg kg−1 dw). The Scheldt and the Seine are still among the most contaminated estuaries in Europe. Each region presented their specific contamination patterns reflecting different sources due to the input of the respective rivers. As fish and fishery products are the main contributors of the total dietary intake of organochlorinated pollutants, regular consumption of European sea bass with the reported contamination levels may represent a significant exposure route for the general human population. [less ▲]

Detailed reference viewed: 78 (22 ULg)
Full Text
Peer Reviewed
See detailToothed whales in the northwestern Mediterranean: Insight into their feeding ecology using chemical tracers
Praca, Emilie; Laran, Sophie; Lepoint, Gilles ULg et al

in Marine Pollution Bulletin (2011), 62(5), 1058-1065

Risso’s dolphins, pilot whales and sperm whales rarely strand in the northwestern Mediterranean. Thus, their feeding ecology, through the analysis of stomach contents, is poorly known. The aim of this ... [more ▼]

Risso’s dolphins, pilot whales and sperm whales rarely strand in the northwestern Mediterranean. Thus, their feeding ecology, through the analysis of stomach contents, is poorly known. The aim of this study was to gain further insight into the segregation/superposition of the diet and habitat of Risso’s dolphins, pilot whales and sperm whales using chemical tracers, namely, stable isotopes (d13C, d15N) and orga- nochlorines. Significantly different d15N values were obtained in Risso’s dolphins (11.7 ± 0.7‰), sperm whales (10.8 ± 0.3‰) and pilot whales (9.8 ± 0.3‰), revealing different trophic levels. These differences are presumably due to various proportions of Histioteuthidae cephalopods in each toothed whale’s diet. Similar d13C contents between species indicated long-term habitat superposition or corroborated impor- tant seasonal migrations. Lower congener 180 concentrations (8.20 vs. 21.73 lg.g􏰀1 lw) and higher tDDT/ tPCB ratios (0.93 vs. 0.42) were observed in sperm whales compared with Risso’s dolphins and may indi- cate wider migrations for the former. Therefore, competition between these species seems to depend on different trophic levels and migration patterns. [less ▲]

Detailed reference viewed: 44 (8 ULg)
Full Text
Peer Reviewed
See detailChlordecone Exposure and Risk of Prostate Cancer
Multigner, Luc; NDong, Jean-Rodrigue; Giusti, Arnaud ULg et al

in Journal of Clinical Oncology (2010)

Detailed reference viewed: 103 (27 ULg)
Full Text
See detailEffects of androgenic and anti-androgenic substances on the freshwater gastropod Lymnaea stagnalis
Giusti, Arnaud ULg; Ducrot, Virginie; Joaquim-Justo, Célia ULg et al

Poster (2010, May 25)

Knowledge on the impacts of endocrine disrupting chemicals (EDCs) on gastropods is scarce and their mechanisms of action are still poorly understood. In this study, effects of 3 androgens (tributyltin ... [more ▼]

Knowledge on the impacts of endocrine disrupting chemicals (EDCs) on gastropods is scarce and their mechanisms of action are still poorly understood. In this study, effects of 3 androgens (tributyltin, testosterone and fenitrothion), 2 anti-androgens (cyproterone acetate and vinclozolin) and 1 estrogen (chlordecone) on growth and reproduction were investigated in the hermaphrodite gastropod Lymnaea stagnalis. [less ▲]

Detailed reference viewed: 76 (6 ULg)
Full Text
See detailImpact of anti-androgens on the production of spermatozoa in Brachionus calyciflorus
Joaquim-Justo, Célia ULg; Cruciani, Valentina ULg; BLASZCZYK, Marie ULg et al

Poster (2010, May 23)

Putative endocrine disruptors affect rate of fertilization of sexual females by males. Preston et al. (2000) reported a decrease in fertilization rate following exposition to, notably, flutamide at 10µg/l ... [more ▼]

Putative endocrine disruptors affect rate of fertilization of sexual females by males. Preston et al. (2000) reported a decrease in fertilization rate following exposition to, notably, flutamide at 10µg/l. We observed similar effects with fenitrothion. Cross mating experiments showed that the decrease in fertilization rate is due to an impact on males exclusively. We studied the impact of anti-androgens on spermatogenesis and observed a decrease in the spermatozoa production with concentrations down to 0,5 mg L-1.We also report a detailed description of the morphology of the male reproductive apparatus in B. calyciflorus based on optic and electronic microscopy analysis and we describe the effect of anti-androgens on males and spermatogenesis in males. [less ▲]

Detailed reference viewed: 24 (6 ULg)
See detailImpacts of androgenic and antiandrogenic substances on the freshwater pulmonate gastropod Lymnaea stagnalis
Giusti, Arnaud ULg; Lagadic, Laurent; Joaquim-Justo, Célia ULg et al

Poster (2010, May 23)

Knowledge on the impacts of endocrine disruptors on gastropods is scarce and their mechanism of action poorly understood especially the impacts of androgenic and antiandrogenic compounds. In this study ... [more ▼]

Knowledge on the impacts of endocrine disruptors on gastropods is scarce and their mechanism of action poorly understood especially the impacts of androgenic and antiandrogenic compounds. In this study effects of 5 androgenics and antiandrogenics endocrine disruptors were investigated on the reproduction and life traits of the freshwater pulmonate gastropod Lymnaea stagnalis. The chemicals tested were Tributyltin, Cyproterone acetate, Methyltestosterone, Vinclozolin and Fenitrothion. Tributyltin was used as androgenic positive control. The other compounds tested are androgenic and antiandrogenic compounds either steroids or non steroids. Adult snails were exposed to 3 concentrations of each chemical for 30 days. The size and reproductive organs development were monitored throughout exposure. The number of clutches, the number of eggs per clutch were assessed during the first 10 days. The clutches were kept individually in clear water except for the clutches of the eighth day which were divided in two. Half was kept individually in clear water and the other half was individually reared in contaminated water following the same exposure as their parents. The percentage of hatching per clutch of these clutches was measured. The development size, mortality, and development of reproductive organs of the juveniles were assessed until their first clutch was laid. [less ▲]

Detailed reference viewed: 23 (5 ULg)
Full Text
Peer Reviewed
See detailRelationships between vitamin A and PCBs in grey seal mothers and pups during lactation
Vanden Berghe, Marie; Mat, Audrey; Arriola, Aline et al

in Environmental Pollution (2010), 158(5), 1570-1575

A previous study has shown a simultaneous increase of vitamin A and PCBs in grey seal (Halichoerus grypus) milk at late lactation (Debier et al., 2004). Here we sought to understand this unexpected ... [more ▼]

A previous study has shown a simultaneous increase of vitamin A and PCBs in grey seal (Halichoerus grypus) milk at late lactation (Debier et al., 2004). Here we sought to understand this unexpected relationship by comparing the dynamics of vitamin A and PCBs in the different tissue compartments of transfer. Lactating grey seals and their pups were sampled longitudinally in Scotland during the 2006 breeding season. As blubber reserves decreased, concentrations of vitamin A and PCBs increased during lactation in the inner layer of maternal blubber. A concomitant rise was observed in milk and consequently in the serum of suckling pups. The similar dynamics of vitamin A and PCBs in milk and inner blubber suggest a common mechanism of mobilisation from maternal body stores and transfer into the milk. A panel data analysis highlighted a negative impact of PCBs in milk and pup serum on vitamin A status in pup serum. © 2009 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 18 (2 ULg)
Full Text
See detailOrganochlorine pollutants in sea turtles and their association with vitamin A
Dyc, Christelle ULg; Debier, Cathy; Thomé, Jean-Pierre ULg et al

Poster (2010, May)

Detailed reference viewed: 50 (15 ULg)
Full Text
Peer Reviewed
See detailMaternal transfer of chlorinated contaminants in the leatherback turtles, Dermochelys coriacea, nesting in French Guiana
Guirlet, Elodie ULg; Das, Krishna ULg; Thomé, Jean-Pierre ULg et al

in Chemosphere (2010), 79(7), 720-726

We examined the maternal transfer of organochlorine contaminants (OCs), pesticides (DDTS and HCHs) 26 and polychlorinated biphenyls (PCBs), and the temporal variation of blood and eggs concentrations from ... [more ▼]

We examined the maternal transfer of organochlorine contaminants (OCs), pesticides (DDTS and HCHs) 26 and polychlorinated biphenyls (PCBs), and the temporal variation of blood and eggs concentrations from 27 38 leatherback turtles (Dermochelys coriacea) nesting in French Guiana. PCBs were found to be the dom- 28 inant OCs with respective mean concentrations of 55.14 ng g 1 lipid-mass for egg and 1.26 ng mL 1 wet- 29 mass for blood. OC concentrations were lower than concentrations measured in other marine turtles 30 which might be due to the lower trophic position (diet based on gelatinous zooplankton) and to the loca- 31 tion of their foraging and nesting grounds. All OCs detected in leatherback blood were detected in eggs, 32 suggesting a maternal transfer of OCs. This transfer was shown to depend on female blood concentration 33 for RDDTs and for the most prevalent PCB congeners, since significant relationships were found between 34 paired blood–egg concentrations. During the nesting season, OC concentrations in eggs and the percent- 35 age of lipid in eggs were found to decline in successive clutches, highlighting a process of offloading from 36 females to their eggs and a decreasing investment of lipid from females into their clutches. OCs in eggs 37 tended to be higher in females spending 3 years in the foraging grounds between two nesting seasons 38 than in those spending 2 years, suggesting an impact of time spacing two breeding seasons, called remi- 39 gration interval, and of location of the foraging grounds. [less ▲]

Detailed reference viewed: 53 (16 ULg)
Full Text
Peer Reviewed
See detailPesticide exposure of pregnant women in Guadeloupe: Ability of a food frequency questionnaire to estimate blood concentration of chlordecone
Guldner, Laurence; Multigner, Luc; Héraud, Fanny et al

in Environmental Research (2010), 110(2), 146-151

Context Chlordecone, an environmentally persistent organochlorine insecticide used intensively in banana culture in the French West Indies until 1993, has permanently polluted soils and contaminated ... [more ▼]

Context Chlordecone, an environmentally persistent organochlorine insecticide used intensively in banana culture in the French West Indies until 1993, has permanently polluted soils and contaminated foodstuffs. Consumption of contaminated food is the main source of exposure nowadays. We sought to identify main contributors to blood chlordecone concentration (BCC) and to validate an exposure indicator based on food intakes.Material and methods We used a food frequency questionnaire (FFQ) completed by a sample of 194 pregnant women to estimate their dietary exposure to chlordecone and compared it to blood levels. In a first approach, chlordecone daily intake was estimated as the product of daily eaten quantity of 214 foodstuffs, multiplied by their chlordecone content, and summed over all items. We then predicted individual blood chlordecone concentration with empirical weight regression models based on frequency of food consumption, and without contamination data.Results Among the 191 subjects who had BCC determination, 146 (76%) had detectable values and mean BCC was 0.86†ng/mL (range < LOD-13.2). Mean per capita dietary intake of chlordecone was estimated at 3.3†[mu]g/day (range: 0.1-22.2). Blood chlordecone levels were significantly correlated with food exposure predicted from the empirical weight models (r=0.47, p<0.0001) and, to a lesser extent, with chlordecone intake estimated from food consumption and food contamination data (r=0.20, p=0.007). Main contributors to chlordecone exposure included seafood, root vegetables, and Cucurbitaceous.Conclusion These results show that the Timoun FFQ provides valid estimates of chlordecone exposure. Estimates from empirical weight models correlated better with blood levels of chlordecone than did estimates from the dietary intake assessment. [less ▲]

Detailed reference viewed: 88 (20 ULg)
Peer Reviewed
See detailPolychlorinated Biphenyls affect Histological Appearance of European sea bass (Dicentrarchus labrax) Thyroids
Schnitzler, Joseph ULg; Klaren, Peter; Celis, Niko et al

Conference (2010)

Polychlorobiphenyls (PCBs) are well-described endocrine disrupters and of particular interest are effects on thyroid function. We propose here a thorough approach to assess effects of these compounds on ... [more ▼]

Polychlorobiphenyls (PCBs) are well-described endocrine disrupters and of particular interest are effects on thyroid function. We propose here a thorough approach to assess effects of these compounds on the thyroid function of European sea bass (Dicentrarchus labrax). An experimental exposure of sea bass to commercial PCB mixtures has been designed to understand underlying toxicity mechanisms and effects on the thyroid system. After 120 days of exposure histological appearance of thyroid tissue was assessed by light and electron microscopy. The follicle area, perimeter, diameter, length and with of every follicle cross section were interactively measured. The shape of the follicles was described with three dimensionless shape descriptors: roundness, form factor and aspect ratio. The histomorphometrical analysis showed a greater heterogeneity of thyroid follicle diameter and especially higher epithelial cell heights in sea bass exposed to environmental relevant doses of PCB (from 0.3 to 0.9 μg g-1 [7 ICES PCB]). Ultrastructural histological investigations showed that the epithelial cells surrounding the bigger follicles present an higher accumulation of colloid droplets. This was interpreted to be the result of increased stimulation of follicular cells. No differences in shape could be identified among the different treatment groups The size of the follicles and the form of the follicular cells gives an indication of the secretary activity of the gland. These observations support the hypothesis that the contamination of PCB mixtures can induce a hyperactivity of the thyroid tissue. These observations were confirmed by measurements of muscular thyroid hormone concentrations and activity thyroid hormone metabolism. [less ▲]

Detailed reference viewed: 76 (1 ULg)
Full Text
Peer Reviewed
See detailEffects of Polychlorinated Biphenyls on Thyroid Hormone Physiology and Metabolism of European sea bass (Dicentrarchus labrax)
Schnitzler, Joseph ULg; Klaren, Peter; Celis, Niko et al

Conference (2010)

Studies in the laboratory have shown that a number of synthetic and natural chemicals can interfere with the endocrine system in fish. Among them, organic compounds such as pesticides and ... [more ▼]

Studies in the laboratory have shown that a number of synthetic and natural chemicals can interfere with the endocrine system in fish. Among them, organic compounds such as pesticides and polychlorobiphenyls (PCBs) are well described endocrine disrupters. Of particular interest are effects on thyroid function, but data on effects of PCB exposure on these hormones and related metabolism has been lacking. We propose here a thorough approach to assess effects of these compounds on the thyroid function of European sea bass (Dicentrarchus labrax). An experimental exposure of sea bass to commercial PCB mixtures has been designed to understand underlying toxicity mechanisms and effects on the thyroid system. After 120 days of exposure, muscular thyroid hormone concentrations and the main metabolic pathways for thyroid hormones (deiodination, glucuronidation and sulfatation) were assessed. Exposure to environmental relevant doses of PCB (from 0.3 to 0.9 ppm [7 ICES PCB]). alters hepatic T4 outer ring deiodinase and T4 sulfatation whereas T4 glucuronidation was not affected. Owing to the extensive autoregulatory feedback at both central and peripheral levels, the thyroid hormone concentrations were preserved despite the PCB induced changes in thyroid hormone dynamics. At 10 times higher concentrations (10 ppm [7 ICES PCB]). an important depression of muscular T3 and T4 levels could be observed which are apparently caused by other mechanisms than metabolic pathways. Further analysis is required to evaluate thyroid gland function and secretion. These results support the observations made in our field study in wild sea bass (Dicentrarchus labrax) from coastal regions near several important European rivers mouths. [less ▲]

Detailed reference viewed: 43 (5 ULg)
Full Text
Peer Reviewed
See detailApproaches for assessing potential impacts of thyroid hormone disrupting chemicals in wild sea bass (Dicentrarchus labrax)
Schnitzler, Joseph ULg; Klaren, Peter; Thomé, Jean-Pierre ULg et al

Poster (2010)

Organic compounds such as pesticides and polychlorobiphenyls (PCBs) are well described endocrine disrupters; of particular interest are effects on thyroid function. To assess the ability of occurring ... [more ▼]

Organic compounds such as pesticides and polychlorobiphenyls (PCBs) are well described endocrine disrupters; of particular interest are effects on thyroid function. To assess the ability of occurring pollutants in European coastal areas to disrupt the thyroid system in sea bass, a field study in the major European estuaries, namely, the Scheldt, the Seine, the Loire, the Charente and the Garonne has been conducted. Several thyroid endpoints were simultaneously examined. Diameter of follicles and the epithelial cell heights give an indication on the production and secretion activity of the thyroid gland. The activity of enzymes involved in the metabolism (deiodination, glucuronidation and sulfatation) of thyroid hormones was analyzed. Finally thyroxine (T4) and triiodothyronine (T3) concentrations were analyzed in muscle by radioimmunoassay. The combined use of all those endpoints gives us an overview of the complex thyroid hormone system. PCB concentration in wild fish varied from 10 to 100 ng g-1 wet weight (ww) depending on length and location. Each region has its own contamination levels and profiles reflecting the contribution of pollutants from rivers. The contamination levels were as follows: the highest concentrations were measured in individuals collected from the coastal region near the Scheldt > Seine > Loire > Charente and the lowest levels were observed in sea bass from coastal regions near the Garonne. Measurements of metabolic activity revealed an altered hepatic T4 outer ring deiodinase whereas T4 sulfatation and T4 glucuronidation were not affected. Owing to the extensive autoregulatory feedback at both central and peripheral levels, the thyroid hormone concentrations were preserved despite the PCB induced changes in thyroid hormone dynamics. [less ▲]

Detailed reference viewed: 26 (3 ULg)
Full Text
See detailToxicodynamic of pollutants in poïkilotherm species
Dyc, Christelle ULg; Bouquegneau, Jean-Marie ULg; Debier, Cathy et al

Poster (2009, November 27)

Detailed reference viewed: 24 (6 ULg)