Search results for "POLYCHLORINATED BIPHENYLS"
showing 10 items of 82 documents
Xenobiotic metabolizing enzymes of rat liver nonparenchymal cells.
1986
Abstract The nonparenchymal cells (NPC) of the liver are primarily located along the sinusoids and therefore are the first cells to encounter blood-borne xenobiotics. To study the possible role of the NPC in the metabolism of xenobiotics, populations of NPC and parenchymal cells (PC) were prepared from rats and various xenobiotic metabolizing enzyme activities investigated. The specific activity of every enzyme studied (ethoxyresorufin deethylase, benzphetamine demethylase, glutathione transferase, UDP glucuronosyltransferase, and microsomal epoxide hydrolase) was 12 to 1000% higher in the PC than in the NPC populations and the patterns of activities between the two populations were remarka…
Polychlorinated biphenyls affect histone modification pattern in early development of rats: a role for androgen receptor-dependent modulation?
2012
Background: The epigenome represents an important target of environmental pollution. Early-life exposure to polychlorinated biphenyls (PCBs) modifies sex steroid enzymes and receptor transcription patterns. Steroid receptors, such as androgen receptor (AR), function as coregulators of histone modification enzymes. Aim: To clarify if a PCB early-life exposure might affect the epigenome in rat liver, we analyzed some histone post-translational modifications (H3K4me3 and H4K16Ac) and the corresponding histone remodeling enzymes, and the AR as a histone enzyme coregulator. Results: We observed a decrease of H4K16Ac and H3K4me3 levels, possibly linked to the induction of chromatin-modifying enz…
Method development for the simultaneous determination of polybrominated, polychlorinated, mixed polybrominated/chlorinated dibenzo-p-dioxins and dibe…
2013
An analytical methodology was developed for simultaneous determination of five groups of persistent organic pollutants (POPs) including polybrominated, polychlorinated and mixed brominated-chlorinated dibenzo-p-dioxins and dibenzofurans (PBDD/DFs, PCDD/DFs and PXDD/DFs, respectively), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in fish samples. The presented analytical approach was based on well established and robust method for determination of PCDD/DFs and PCBs, which was augmented with gas chromatography coupled to high resolution mass spectrometry (GC-HRMS) to include PBDEs, as well as poorly investigated PBDD/DFs and PXDD/DFs at toxicologically significa…
Prenatal and postnatal exposure to persistent organic pollutants and attention-deficit and hyperactivity disorder: a pooled analysis of seven Europea…
2018
International audience; Background - Attention-deficit/hyperactivity disorder (ADHD) is increasing worldwide for reasons largely unknown and environmental chemicals with neurotoxic properties, such as persistent organic pollutants (POPs), have been proposed to play a role. We investigated the association between prenatal and postnatal exposure to polychlorinated biphenyl-153 (PCB-153), p-p´-dichlorodiphenyldichloroethylene (p-p'-DDE) and hexachlorobenzene (HCB) and ADHD in childhood. Methods - We pooled seven European birth cohort studies encompassing 4437 mother-child pairs from the general population with concentrations of PCB-153, p-p´-DDE and HCB measured in cord blood, maternal blood o…
Birth Weight and Prenatal Exposure to Polychlorinated Biphenyls (PCBs) and Dichlorodiphenyldichloroethylene (DDE): A Meta-analysis within 12 European…
2011
Abstract: Objectives: Exposure to high concentrations of persistent organochlorines may cause fetal toxicity, but the evidence at low exposure levels is limited. Large studies with substantial exposure contrasts and appropriate exposure assessment are warranted. Within the framework of the EU (European Union) ENRIECO (ENvironmental Health RIsks in European Birth Cohorts) and EU OBELIX (OBesogenic Endocrine disrupting chemicals: LInking prenatal eXposure to the development of obesity later in life) projects, we examined the hypothesis that the combination of polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE) adversely affects birth weight. Methods: We used maternal a…
Bioaccumulation of persistent organic pollutants in the gonads of Barbus barbus (Linnaeus, 1758)
2020
Maps with grey or even white spaces are still present in spite of the fact that persistent organic pollutants (POPs) are at the forefront of research in aquatic toxicology and environmental safety. This is also the case for the Mureș River basin. The intensive use of industrial substances such as polychlorinated biphenyls (PCBs) and pesticides such as organochlorine compounds (OCPs) has caused global contamination of the aquatic environment. In our study we have found very high concentrations of both PCBs (2110-169,000 ng/g lipid weight ΣPCB, 1950-166,000 ng/g lipid weight ΣPCB7) and OCPs (1130-7830 ng/g lipid weight ΣDDT, 47.6-2790 ng/g lipid weight ΣHCH, 5.53-35.6 ng/g lipid weight ΣChlor…
Androgen receptor activation by polychlorinated biphenyls
2013
The exposure to environmental endocrine disrupting compounds (EDC), as polychlorinated biphenyls (PCBs), widely diffused in the environment may produce epigenetic changes that affect the endocrine system. We found that PCBs activate AR transcriptional activity and that this effect is potentiated by the demethylase Jarid1b, a histone demethylase that catalyzes the removal of trimethylation of lysine 4 on histone H3 (H3K4me3), induced by PCB. The aim of the present study was to investigate the effect of the treatment of cultured cells (HEK293) with a mixture of the most diffused environmental PCBs and, also with dihydrotestosterone (DHT), on the functional interaction between AR and Jarid1b. …
Cancer Risk Near a Polluted River in Finland
2004
The River Kymijoki in southern Finland is heavily polluted with polychlorinated dibenzo-p-dioxins and dibenzofurans and may pose a health threat to local residents, especially farmers. In this study we investigated cancer risk in people living near the river (less than 20.0 km) in 1980. We used a geographic information system, which stores registry data, in 500 m times 500 m grid squares, from the Population Register Centre, Statistics Finland, and Finnish Cancer Registry. From 1981 to 2000, cancer incidence in all people (N = 188884) and in farmers (n = 11132) residing in the study area was at the level expected based on national rates. Relative risks for total cancer and 27 cancer subtype…
Biomonitoring of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs)…
2020
Abstract The main objective of the present research was to evaluate the levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in the human milk of Spanish lactating women who participated in the BETTERMILK project so that exposure and risk could be assessed for these mothers and their breastfed children. The total ∑PCDD/Fs + dl-PCBs TEQ2005 concentrations in the upper-bound (UB) ranged from 1.29 to 13.48 pg TEQ2005 g−1 lipid. The estimated geometric mean level for the sum of PCDD/F and dl-PCBs was 4.10 and 4.42 pg TEQ2005 g−1 lipid, lower-bound (LB) and UB respectively and were below the reference leve…
Toxicological Profile of Ultrapure 2,2´,3,4,4´,5,5´-Heptachlorbiphenyl (PCB 180) in Adult Rats
2014
PCB 180 is a persistent non-dioxin-like polychlorinated biphenyl (NDL-PCB) abundantly present in food and the environment. Risk characterization of NDL-PCBs is confounded by the presence of highly potent dioxin-like impurities. We used ultrapure PCB 180 to characterize its toxicity profile in a 28-day repeat dose toxicity study in young adult rats extended to cover endocrine and behavioral effects. Using a loading dose/maintenance dose regimen, groups of 5 males and 5 females were given total doses of 0, 3, 10, 30, 100, 300, 1000 or 1700 mg PCB 180/kg body weight by gavage. Dose-responses were analyzed using benchmark dose modeling based on dose and adipose tissue PCB concentrations. Body w…