Development of a LC-UV-MS analytical method for aldehydes formed during fatty acids degradation

Poster (2012)

Analyse sensorielle et biochimique du Tilapia du Nil (Oreochromis niloticus) conservé à température ambiante (30°C) et à 4°C

Poster (2012)

Development of a LC-UV-MS analytical method for malondialdehyde.

Poster (2011)

Development of a LC-UV-MS analytical method for aldehydes formed during fatty acids degradation.

Poster (2011)

Understanding the gap between the estrogenicity of an effluent and its real impact into the wild

in Science of the Total Environment (2010), 408(4), 812-821

To study the reliability between in vitro and in vivo data collected downstream 2 sewage treatment plants (STP) as well as from bleached kraft mill industry (BKME), 5 rivers (3 impacted and 2 references ... [more ▼]

To study the reliability between in vitro and in vivo data collected downstream 2 sewage treatment plants (STP) as well as from bleached kraft mill industry (BKME), 5 rivers (3 impacted and 2 references) were investigated in the Walloon region (southern of Belgium). For the in vitro part of the work, water samples were collected to measure the estrogenicity of the ‘out’ effluent compared to reference sample point by MCF-7 assay. Results indicated significant estrogenicity of effluents from STP and BKME and a weak estrogenicity in reference sites. However, estradiol equivalents (EEQ) estimated into rivers were probably too low to impact wild population. Chemical analysis of 13 compounds of interest indicated that extraction procedure used in this study gave low recoveries of estrogen-like xenobiotics, leading to probably under-estimated MCF-7 responses. Surprisingly, a full scan mode has revealed an unexpected compound in the sample of BKME which was: 7-isopropyl-1,1,4a-trimethyl-1,2,3,4a,9,10,10a-octahydrophenanthrene, a product of pulp mill manufacture. In parallel to in vitro, in vivo assessment of estrogenic impact of effluent was followed on the gudgeon (Gobio gobio). Samples were achieved during 2 different periods of the reproductive cycle, resting period (RP) and pre-spawning period (pSP). Unspecific physiological parameters to estrogenic exposure (gonadosomatic index and systematic testis cell counting) displayed no significant differences related to endocrine disruption of the reproductive tract, only differences were correlated with the reproductive state of fish (RP versus pSP). Concerning the potent biomarker of estrogen exposure, vitellogenin (vtg), only basal induction was revealed but not related to estrogenic exposure. Nevertheless, vtg over-expression was found for male fish presenting a feminization of the reproductive tract captured downstream the STP station of Wégnez in the Vesdre River. Intersexuality, another indicator of the estrogenicity impact in fish, was observed in every site. Actually, ovotestis was systematically formed by protoplasmic oocyte observed in low percentage in every group analysed (impacted and references). Moreover, in fish captured in Wégnez, oocyte diameter was significantly higher compared to the other groups. In this study, only moderate to none impact in population of gudgeon was noticed. Moreover, in this case no discrepancy between in vitro and vivo was viewed although both approaches revealed gaps in monitoring effluent incidence into the environment. We should remain careful in the interpretation when only partial approaches are used in order to characterize impact in the aquatic milieu. [less ▲]

EVALUATION OF THE CONTAMINATION OF NORTH SEA PORPOISES (Phocoena phocoena) BY ENDOCRINE DISRUPTING CHEMICALS USING GC-MS AND IN VITRO ASSAYS

Poster (2009, May 20)

Development of a liquid/tandem mass spectrometry method to study kinetics of enrofloxacin and ciprofloxacin elimination in two species of aquaculture products

Poster (2009, May 19)

Evaluation of the endorcine disrupting chemicals contamination in the North Sea porpoise population using in vitro assays

Poster (2009)

During the last decades, the production endocrine disrupting chemicals reached such levels that they are now spread all over nature. They are known to be very slowly degraded, decreasing the environmental ... [more ▼]

During the last decades, the production endocrine disrupting chemicals reached such levels that they are now spread all over nature. They are known to be very slowly degraded, decreasing the environmental quality and posing ecological risks. Marine mammals inhabiting polluted environments accumulate high levels of these chemicals, so they can be considered good indicators of marine pollution. Thirteen major organochloride pollutants were chosen to make subject of this study: o,p’-DDD; p,p’-DDD; p,p’-DDE; o,p’-DDT; p,p’-DDT; HCB; α-HCH; β-HCH; γ-HCH; δ-HCH; PCB 138; PCB 153 and PCB 180. All these chemicals will have their endocrine disrupting effects characterized individually and collectively by report gene expression assays. The MCF7-ERE cells used in these assays were produced in the Molecular Biology and Genetic Engineering Laboratory of the University of Liège and are originated from a human mammary carcinoma. They carry a gene expressing the synthesis of luciferase and controlled by oestrogen receptors. Then, the thirteen chemicals will be searched in the blubber tissues of porpoises by the use of gas chromatography-mass spectrometry. The blubber samples will also have their endocrine disrupting effect characterized. For the moment, the estrogenic effects of the HCH isomers were put in evidence. The next steps of this work must be soon accomplished. It is expected a great level of these compounds to be found in the samples. On the other hand, their endocrine disrupting effects and how they act in agonist, antagonist and synergist ways are subject that still needs to be cleared. [less ▲]

Levels of dioxin in serum of pregnant women living nearby a paper mill industry, in the province of Valdivia, Chile

in Organohalogen Compounds (2009), 71

Cell based assay dioxin screening: utilisation of three new cellular bioassays from different species and tissues

in Organohalogen Compounds (2008), 70