Acute alteration of cardiac ECG, action potential, I{sub Kr} and the human ether-a-go-go-related gene (hERG) K{sup +} channel by PCB 126 and PCB 77

Energy Technology Data Exchange (ETDEWEB)

Park, Mi-Hyeong; Park, Won Sun; Jo, Su-Hyun, E-mail: suhyunjo@kangwon.ac.kr

2012-07-01

Polychlorinated biphenyls (PCBs) have been known as serious persistent organic pollutants (POPs), causing developmental delays and motor dysfunction. We have investigated the effects of two PCB congeners, 3,3′,4,4′-tetrachlorobiphenyl (PCB 77) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) on ECG, action potential, and the rapidly activating delayed rectifier K{sup +} current (I{sub Kr}) of guinea pigs' hearts, and hERG K{sup +} current expressed in Xenopus oocytes. PCB 126 shortened the corrected QT interval (QTc) of ECG and decreased the action potential duration at 90% (APD{sub 90}), and 50% of repolarization (APD{sub 50}) (P < 0.05) without changing the action potential duration at 20% (APD{sub 20}). PCB 77 decreased APD{sub 20} (P < 0.05) without affecting QTc, APD{sub 90}, and APD{sub 50}. The PCB 126 increased the I{sub Kr} in guinea-pig ventricular myocytes held at 36 °C and hERG K{sup +} current amplitude at the end of the voltage steps in voltage-dependent mode (P < 0.05); however, PCB 77 did not change the hERG K{sup +} current amplitude. The PCB 77 increased the diastolic Ca{sup 2+} and decreased Ca{sup 2+} transient amplitude (P < 0.05), however PCB 126 did not change. The results suggest that PCB 126 shortened the QTc and decreased the APD{sub 90} possibly by increasing I{sub Kr}, while PCB 77 decreased the APD{sub 20} possibly by other modulation related with intracellular Ca{sup 2+}. The present data indicate that the environmental toxicants, PCBs, can acutely affect cardiac electrophysiology including ECG, action potential, intracellular Ca{sup 2+}, and channel activity, resulting in toxic effects on the cardiac function in view of the possible accumulation of the PCBs in human body. -- Highlights: ► PCBs are known as serious environmental pollutants and developmental disruptors. ► PCB 126 shortened QT interval of ECG and action potential duration. ► PCB 126 increased human ether-a-go-go-related K{sup +} current and I{sub Kr}. �

Gestational 3,3',4,4',5-pentachlorobiphenyl (PCB 126) exposure disrupts fetoplacental unit: Fetal thyroid-cytokines dysfunction.

Science.gov (United States)

Ahmed, R G; El-Gareib, A W; Shaker, H M

2018-01-01

Exposure to polychlorinated biphenyls (PCBs) is related to several endocrine disorders. This study examined the effect of maternal exposure of 3,3',4,4',5-pentachlorobiphenyl (PCB 126) on the fetoplacental unit and fetal thyroid-cytokine axis during the pregnancy. Pregnant albino rats received PCB 126 (20 or 40μg/kgb.wt.) by oral gavage from gestation day (GD) 1 to 20. Potential effects of PCB 126 were evaluated by following the histopathological changes in the placenta by Haematoxylin and Eosin (H&E) stain and measuring the maternofetal thyroid axis (ELIZA), maternofetal body weight, and fetal growth markers (ELIZA), and cytokines (ELIZA) at embryonic day (ED) 20. Placental tissues of both treated groups showed hyperemia, hemorrhage, degeneration and apoptosis in labyrinth layer and spiral artery at GD 20. Both administrations of PCB 126 elevated serum thyrotropin (TSH) concentration, and decreased free thyroxine (FT4) and free triiodothyronine (FT3) concentrations, resulting in a maternofetal hypothyroidism. The presence of hypothyroidism increased fetal serum concentration of transforming growth factor-β (TGF-β), leptin (LEP), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and decreased the fetal serum insulin growth factor-I (IGF-I), IGF-II, insulin, adiponectin (ADP), and growth hormone (GH) in both treated groups at ED 20. However, the increase in resistin (RETN) and interferon-γ (IFN-γ) was non-significant in low-dose group and highly significant in high-dose group. Simultaneously, the reduction in body weight of the dams and fetuses was observed in both PCB 126 groups of examined day with respect to the control group. The maternal PCB 126 distorted the fetoplacental unit might disrupt the fetal thyroid-cytokines axis and prenatal development. Copyright © 2017 Elsevier Inc. All rights reserved.

Identification of lipidomic markers of chronic 3,3',4,4',5-pentachlorobiphenyl (PCB 126) exposure in the male rat liver.

Science.gov (United States)

Kania-Korwel, Izabela; Wu, Xianai; Wang, Kai; Lehmler, Hans-Joachim

2017-09-01

Exposure to PCB 126, an environmentally relevant aryl hydrocarbon receptor agonist, is an environmental factor causing hepatic steatosis in rodent models; however, the lipidome of PCB 126-exposed rats has not been investigated in-depth. The objective of the present study was therefore to characterize dose-dependent changes in the lipid profile in the liver of male Sprague-Dawley rats exposed to PCB 126. Rats were exposed for three month to intraperitoneal injections of 0.01, 0.05 and 0.2μmol/kg bw PCB 126 in corn oil. Control animals were exposed in parallel and received corn oil alone. Lipids were extracted from whole liver homogenate and levels of polar lipids and fatty acids incorporated into triglycerides (FA TAGs ) were determined with tandem mass spectrometry using electrospray ionization. PCB 126 exposure increased the hepatic content of polar lipids and FA TAGs . Protein adjusted levels of several polar lipid classes, in particular phosphatidylserine levels, decreased, whereas FA TAGs levels typically increased with increasing PCB 126 dose. Sensitive, dose-dependent endpoints of PCB 126 exposure included an increase in levels of adrenic acid incorporated into triglycerides and changes in levels of certain ether-linked phospholipid and 1-alkyl/1-alkenyldiacylglycerol species, as determined using partial least square discriminant analysis (PLS-DA) and ANOVA. These changes in the composition of polar lipids and fatty acid in the liver of PCB 126 exposed rats identified several novel markers of PCB 126-mediated fatty liver disease that need to be validated in further studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Dioxin-like (PCB 126) and non dioxin-like (PCB 153) action on DNA damage and apoptosis in granulosa cells. Preliminary data

Energy Technology Data Exchange (ETDEWEB)

Gregoraszczuk, E.L.; Wojtowicz, A. [Lab. of Physiology and Toxicology of Reproduction, Inst. of Zoology, Jagiellonian Univ., Krakow (Poland); Kapiszewska, M.; Magnowska, Z. [Dept. of General Biochemistry, Jagiellonian Univ., Krakow (Poland)

2004-09-15

Introduction Approximately 60-90% of all cancer cases are now generally believed to be due to environmental factors, to which humans are exposed by taking food, and water or inhaling air. These chemicals, including polycyclic aromatic hydrocarbons (PAHs), can be subdivided into different classes. TCDD was classified as group (documented carcinogen in humans) Benzo [a] pyrene and benzo [a] anthracene were included into group 2A (probably carcinogen in humans). PCB is not mentioned in this list. The International Agency for Research on Cancer (IARC) maintains a register of human carcinogens and suspected human carcinogens. The capacity of PCBs to induce DNA strand breaks has been studied to a lesser degree and is quite controversial. DNA strand breaks are the potentially mutagenic lesions that have been proposed as a genotoxicity biomarker for the biomonitoring of environmental pollutants. The mutations induced by these lesions in pollutant-exposed populations are believed to be induced by chemical carcinogens. The formation of PCB adducts has been demonstrated and measured in vitro and in vivo 3. The capacity of PCBs to form DNA adducts depends on their metabolic rate, which is determined by the degree of chlorination. The aim of the presented preliminary data was to evaluate the follicular stage-specific action of PCB 126 and PCB 153 on DNA damage and apoptosis in granulosa cells.

Effect of PCB 126 on aryl hydrocarbon receptor 1 (AHR1) and AHR1 nuclear translocator 1 (ARNT1) mRNA expression and CYP1 monooxygenase activity in chicken (Gallus domesticus) ovarian follicles.

Science.gov (United States)

Wójcik, Dagmara; Antos, Piotr A; Katarzyńska, Dorota; Hrabia, Anna; Sechman, Andrzej

2015-12-03

The aim of the experiment was to study the in vitro effect of 3,3',4,4',5-pentachlorobiphenyl (PCB 126; a coplanar PCB congener) on aryl hydrocarbon receptor (AHR1) and AHR1 nuclear translocator (ARNT1) mRNA expression and the activity of CYP1 family monooxygenases in chicken ovarian follicles. White (1-4 mm) and yellowish (4-8 mm) prehierarchical follicles as well as fragments of the theca and granulosa layers of the 3 largest preovulatory follicles (F3-F1) were incubated in a medium supplemented with 0 (control group), 1, 10 or 100 nM PCB 126. The incubation was carried out for 6 h or 24 h for determination of mRNA expression of AHR1 and ARNT1 genes (real-time qPCR) and CYP1 monooxygenase activity (EROD and MROD fluorometric assays), respectively. It was found that chicken ovarian follicles express mRNA of AHR1 and ARNT1 genes. A modulatory effect of PCB 126 on AHR1 and ARNT1 expression depended not only on the biphenyl concentration but also on the follicular layer and the maturational state of the follicle. EROD and MROD activities appeared predominantly in the granulosa layer of the yellow preovulatory follicles. PCB 126 induced these activities in a dose-dependent manner in all ovarian follicles. The obtained results suggest that ovarian follicles, especially the granulosa layer, are involved in the detoxification process of PCBs in the laying hen. Taking this finding into consideration it can be suggested that the granulosa layer of the yellow hierarchical follicles plays a key role in the protective mechanism which reduces the amount of transferred dioxin-like compounds into the yolk of the oocyte. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

3,3′,4,4′,5-Pentachlorobiphenyl (PCB 126) Decreases Hepatic and Systemic Ratios of Epoxide to Diol Metabolites of Unsaturated Fatty Acids in Male Rats

Science.gov (United States)

Wu, Xianai; Yang, Jun; Morisseau, Christophe; Robertson, Larry W.; Hammock, Bruce; Lehmler, Hans-Joachim

2016-01-01

Disruption of the homeostasis of oxygenated regulatory lipid mediators (oxylipins), potential markers of exposure to aryl hydrocarbon receptor (AhR) agonists, such as 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126), is associated with a range of diseases, including nonalcoholic fatty liver disease and nonalcoholic steatohepatitis. Here we test the hypothesis that PCB 126 exposure alters the levels of oxylipins in rats. Male Sprague-Dawley rats (5-weeks old) were treated over a 3-month period every 2 weeks with intraperitoneal injections of PCB 126 in corn oil (cumulative doses of 0, 19.8, 97.8, and 390 µg/kg b.w.; 6 injections total). PCB 126 treatment caused a reduction in growth rates at the highest dose investigated, a dose-dependent decrease in thymus weights, and a dose-dependent increase in liver weights. Liver PCB 126 levels increased in a dose-dependent manner, while levels in plasma were below or close to the detection limit. The ratios of several epoxides to diol metabolites formed via the cytochrome P450 (P450) monooxygenase/soluble epoxide hydrolase (sEH) pathway from polyunsaturated fatty acids displayed a dose-dependent decrease in the liver and plasma, whereas levels of oxylipins formed by other metabolic pathways were generally not altered by PCB 126 treatment. The effects of PCB 126 on epoxide-to-diol ratios were associated with an increased CYP1A activity in liver microsomes and an increased sEH activity in liver cytosol and peroxisomes. These results suggest that oxylipins are potential biomarkers of exposure to PCB 126 and that the P450/sEH pathway is a therapeutic target for PCB 126-mediated hepatotoxicity that warrants further attention. PMID:27208083

Prolonged ELS test with the marine flatfish sole (Solea solea) shows delayed toxic effects of previous exposure to PCB 126

NARCIS (Netherlands)

Foekema, E.M.; Deerenberg, C.M.; Murk, A.J.

2008-01-01

The effect of the dioxin-like PCB 126 (3,3¿,4,4¿,5-pentachlorobiphenyl) on the early development of the marine flatfish sole (Solea solea) was tested in a newly developed early life stage (ELS) test that includes the metamorphosis of the symmetric larvae into an asymmetrical flatfish. Early life

Individual Polychlorinated Biphenyl (PCB) Congeners Produce Tissue- and Gene-Specific Effects on Thyroid Hormone Signaling during Development

Science.gov (United States)

Giera, Stefanie; Bansal, Ruby; Ortiz-Toro, Theresa M.; Taub, Daniel G.

2011-01-01

Polychlorinated biphenyls (PCB) are industrial chemicals linked to developmental deficits that may be caused in part by disrupting thyroid hormone (TH) action by either reducing serum TH or interacting directly with the TH receptor (TR). Individual PCB congeners can activate the TR in vitro when the metabolic enzyme cytochrome P4501A1 (CYP1A1) is induced, suggesting that specific PCB metabolites act as TR agonists. To test this hypothesis in vivo, we compared two combinations of PCB congeners that either activate the TR (PCB 105 and 118) or not (PCB 138 and 153) in the presence or absence of a PCB congener (PCB 126) that induces CYP1A1 in vitro. Aroclor 1254 was used as a positive control, and a group treated with propylthiouracil was included to characterize the effects of low serum TH. We monitored the effects on TH signaling in several peripheral tissues by measuring the mRNA expression of well-known TH-response genes in these tissues. Aroclor 1254 and its component PCB 105/118/126 reduced total T4 to the same extent as that of propylthiouracil but increased the expression of some TH target genes in liver. This effect was strongly correlated with CYP1A1 expression supporting the hypothesis that metabolism is necessary. Effects were gene and tissue specific, indicating that tissue-specific metabolism is an important component of PCB disruption of TH action and that PCB metabolites interact in complex ways with the TR. These are essential mechanisms to consider when evaluating the health risks of contaminant exposures, for both PCB and other polycyclic compounds known to interact with nuclear hormone receptors. PMID:21540284

Theoretical perspectives on the mechanism and kinetics of the OH radical-initiated gas-phase oxidation of PCB126 in the atmosphere

International Nuclear Information System (INIS)

Dang, Juan; Shi, Xiangli; Zhang, Qingzhu; Wang, Wenxing

2015-01-01

Polychlorinated biphenyls (PCBs) primarily exist in the gas phase in air and may undergo atmospheric oxidation degradations, particularly the oxidation reaction initiated by OH radicals. In this work, the mechanism of the OH radical-initiated atmospheric oxidation of the most toxic PCB congener 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) was investigated by using quantum chemistry methods. The rate constants of the crucial elementary reactions were estimated by the Rice–Ramsperger–Kassel–Marcus (RRKM) theory. The oxidation products of the reaction of PCB126 with OH radicals include 3,3′,4,4′,5-pentachlorobiphenyl-ols, chlorophenols, 2,3,4,7,8-pentachlorodibenzofuran, 2,3,4,6,7-pentachlorodibenzofuran, dialdehydes, 3,3′,4,4′,5-pentachloro-5′-nitro-biphenyl, and 4,5-dichloro-2-nitrophenol. Particularly, the formation of polychlorinated dibenzofurans (PCDFs) from the atmospheric oxidation of PCBs is revealed for the first time. The overall rate constant of the OH addition reaction is 2.52 × 10 −13 cm 3 molecule −1 s −1 at 298 K and 1 atm. The atmospheric lifetime of PCB126 determined by OH radicals is about 47.08 days which indicates that PCB126 can be transported long distances from local to global scales. - Highlights: • A comprehensive mechanism of OH-initiated oxidation of PCB126 was investigated. • The formation of PCDFs from the oxidation of PCBs is determined for the first time. • The rate constants for key elementary reactions were estimated by the RRKM theory. • The atmospheric lifetime of PCB126 determined by OH radicals is about 47.08 days

Long-term in vivo polychlorinated biphenyl 126 exposure induces oxidative stress and alters proteomic profile on islets of Langerhans

Science.gov (United States)

Loiola, Rodrigo Azevedo; Dos Anjos, Fabyana Maria; Shimada, Ana Lúcia; Cruz, Wesley Soares; Drewes, Carine Cristiane; Rodrigues, Stephen Fernandes; Cardozo, Karina Helena Morais; Carvalho, Valdemir Melechco; Pinto, Ernani; Farsky, Sandra Helena

2016-06-01

It has been recently proposed that exposure to polychlorinated biphenyls (PCBs) is a risk factor to type 2 diabetes mellitus (DM2). We investigated this hypothesis using long-term in vivo PCB126 exposure to rats addressing metabolic, cellular and proteomic parameters. Male Wistar rats were exposed to PCB126 (0.1, 1 or 10 μg/kg of body weight/day; for 15 days) or vehicle by intranasal instillation. Systemic alterations were quantified by body weight, insulin and glucose tolerance, and blood biochemical profile. Pancreatic toxicity was measured by inflammatory parameters, cell viability and cycle, free radical generation, and proteomic profile on islets of Langerhans. In vivo PCB126 exposure enhanced the body weight gain, impaired insulin sensitivity, reduced adipose tissue deposit, and elevated serum triglycerides, cholesterol, and insulin levels. Inflammatory parameters in the pancreas and cell morphology, viability and cycle were not altered in islets of Langerhans. Nevertheless, in vivo PCB126 exposure increased free radical generation and modified the expression of proteins related to oxidative stress on islets of Langerhans, which are indicative of early β-cell failure. Data herein obtained show that long-term in vivo PCB126 exposure through intranasal route induced alterations on islets of Langerhans related to early end points of DM2.

Tributyltin modulates 3,3',4,4',5-pentachlorobiphenyl (PCB-126)-induced hepatic CYP1A activity in channel catfish, Ictalurus punctatus.

Science.gov (United States)

Rice, C D; Roszell, L E

1998-10-09

Many harbor estuaries and their tributaries are contaminated with halogenated aromatic hydrocarbons (HAHs) and polycyclic aromatic hydrocarbons (PAHs). Planar congeners of these two classes initiate their toxic effects, including reproductive, developmental, and immunological dysfunction, primarily through the cytosolic arylhydrocabon receptor (Ahr). However, only rarely are aquatic environments contaminated with Ahr-binding contaminants alone. Instead, most are impacted by a variety of pollutants in mixture. Tributyltin (TBT), a common antifouling biocide, is also found in many harbor estuaries and their tributaries. Several reports indicate that TBT inhibits the cytochrome P-4501A system of fish, at least in vitro, and our recent studies with rodents indicate that TBT potentiates PCB-induced CYP1A. However, the effects of TBT on xenobiotic-induced CYP1A activity in aquatic organisms has been virtually unexplored. To this end, channel catfish, Ictalurus punctatus, were exposed to 3,3'4,4',5-pentachlorobiphenyl (PCB-126, PeCB), TBT, or both in combination, with corn oil (CO) serving as the carrier control. Immunoreactive CYP1A protein and ethoxyresorufin O-deethylase (EROD) activity were measured after (1) a single dose of 0.01, 0. 1, or 1 mg/kg of each or both in combination, and (2) 6 injections of 0.017, 1.7, or 17 microg/kg of each (or in combination) given every 3 d over a 16-d period to yield a cumulative dose of 0.01, 0.1, or 1 mg/kg. As expected, PeCB alone, but not TBT, greatly induced these two CYP1A parameters. Low and middle doses of TBT (0.01 and 0.1 mg/kg), but not the high dose, potentiated PeCB-induced activity at these same doses. This effect of TBT was even more pronounced in the repeated exposure study. Furthermore, EROD activity did not always reflect CYP1A protein induction; enzyme activity was inhibited by TBT at doses that potentiated protein induction (0.01 and 0.1 mg/kg). In summary, TBT potentiates PeCB-induced CYP1A in channel catfish at

Epigenetic Determinants of CYP1A1 Induction by the Aryl Hydrocarbon Receptor Agonist 3,3',4,4',5-Pentachlorobiphenyl (PCB 126

Directory of Open Access Journals (Sweden)

Sabine U. Vorrink

2014-08-01

Full Text Available Many enzymes involved in xenobiotic metabolism, including cytochrome P450 (CYP 1A1, are regulated by the aryl hydrocarbon receptor (AhR. 3,3',4,4',5-Penta chlorobiphenyl (PCB 126 is a potent ligand for AhR and can thus induce the expression of CYP1A1. Interestingly, we observed that human carcinoma cell lines derived from different types of epithelial cells displayed divergent degrees of CYP1A1 induction after exposure to PCB 126. Since epigenetic mechanisms are known to be involved in cell type-specific gene expression, we sought to assess the epigenetic determinants of CYP1A1 induction in these carcinoma cell lines. In contrast to HepG2 hepatocarcinoma cells, HeLa cervical carcinoma cells showed significantly lower levels of CYP1A1 mRNA expression following PCB 126 exposure. Our results show that the two cell lines maintained differences in the chromatin architecture along the CYP1A1 promoter region. Furthermore, treatment with the epigenetic modifiers, trichostatin A (TSA and 5-aza-2'-deoxycytidine (5-Aza-dC, significantly increased the expression of CYP1A1 after PCB 126 treatment in HeLa cells. However, we did not observe apparent differences in methylation levels or specific location of CpG DNA methylation between the two cell lines in the analyzed CYP1A1 promoter region. Taken together, our findings suggest that the differences in CYP1A1 expression between HepG2 and HeLa cells are due to differences in the chromatin architecture of the CYP1A1 promoter and thus establish a role of epigenetic regulation in cell-specific CYP1A1 expression.

PCB 126 toxicity is modulated by cross-talk between caveolae and Nrf2 signaling

Energy Technology Data Exchange (ETDEWEB)

Petriello, Michael C. [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Han, Sung Gu [University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Department of Food Science and Biotechnology of Animal Resources, College of Animal Bioscience and Technology, Konkuk University, Seoul 143-701 (Korea, Republic of); Newsome, Bradley J. [University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Department of Chemistry, College of Arts and Sciences, University of Kentucky, Lexington, KY 40506 (United States); Hennig, Bernhard [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, KY 40506 (United States)

2014-06-01

Environmental toxicants such as polychlorinated biphenyls (PCBs) have been implicated in the promotion of multiple inflammatory disorders including cardiovascular disease, but information regarding mechanisms of toxicity and cross-talk between relevant cell signaling pathways is lacking. To examine the hypothesis that cross-talk between membrane domains called caveolae and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathways alters PCB-induced inflammation, caveolin-1 was silenced in vascular endothelial cells, resulting in a decreased PCB-induced inflammatory response. Cav-1 silencing (siRNA treatment) also increased levels of Nrf2-ARE transcriptional binding, resulting in higher mRNA levels of the antioxidant genes glutathione s-transferase and NADPH dehydrogenase quinone-1 in both vehicle and PCB-treated systems. Along with this upregulated antioxidant response, Cav-1 siRNA treated cells exhibited decreased mRNA levels of the Nrf2 inhibitory protein Keap1 in both vehicle and PCB-treated samples. Silencing Cav-1 also decreased protein levels of Nrf2 inhibitory proteins Keap1 and Fyn kinase, especially in PCB-treated cells. Further, endothelial cells from wildtype and Cav-1 −/− mice were isolated and treated with PCB to better elucidate the role of functional caveolae in PCB-induced endothelial inflammation. Cav-1 −/− endothelial cells were protected from PCB-induced cellular dysfunction as evidenced by decreased vascular cell adhesion molecule (VCAM-1) protein induction. Compared to wildtype cells, Cav-1 −/− endothelial cells also allowed for a more effective antioxidant response, as observed by higher levels of the antioxidant genes. These data demonstrate novel cross-talk mechanisms between Cav-1 and Nrf2 and implicate the reduction of Cav-1 as a protective mechanism for PCB-induced cellular dysfunction and inflammation. - Highlights: • Reduction of caveolin-1 protein protects against polychlorinated biphenyl toxicity. • Decreasing

Precision-Cut Liver Slices of Salmo salar as a tool to investigate the oxidative impact of CYP1A-mediated PCB 126 and 3-methylcholanthrene metabolism.

Science.gov (United States)

Lemaire, Benjamin; Beck, Michaël; Jaspart, Mélanie; Debier, Cathy; Calderon, Pedro Buc; Thomé, Jean-Pierre; Rees, Jean-François

2011-02-01

Fish isolated cell systems have long been used to predict in vivo toxicity of man-made chemicals. In present study, we tested the suitability of Precision-Cut Liver Slices (PCLS) as an alternative to these models that allows the evaluation of a global tissue response to toxicants, to investigate oxidative stress response to cytochrome P450 1A (CYP1A) induction in fish liver. PCLS of Salmo salar were exposed for 21 h to increasing doses of 3-methylcholanthrene (3-MC) and Polychlorobiphenyl 126 (PCB 126). 3-MC (25 μM) strongly induced CYP1A transcription. In dose-response analysis (25-100 μM), EROD activity was strongly increased at intermediate 3-MC concentrations. We found the counter-intuitive decline of EROD at the highest 3-MC doses to result from reversible competition with ethoxyresorufin. No increases of H(2)O(2) production, antioxidant enzymes activities or oxidative damage to lipids were found with 3-MC treatments. PCLS subjected to PCB 126 (2-200 nM) showed increased contamination levels and a parallel increased CYP1A mRNA synthesis and EROD activity. H(2)O(2) production tended to increase but no oxidative damage to lipids was found. As antioxidant enzymes activities declined at the highest PCB 126 dose, it is suggested that longer incubation periods could be required to generate oxidative stress in PCLS. Copyright © 2010 Elsevier Ltd. All rights reserved.

The effects of the organopollutant PCB 126 on bone density in juvenile diamondback terrapins (Malaclemys terrapin)

Energy Technology Data Exchange (ETDEWEB)

Holliday, Dawn K., E-mail: dawn.holliday@westminster-mo.edu [Department of Biological Sciences and the Appalachian Rural Health Institute, Ohio University, Athens, OH 45701 (United States); Holliday, Casey M., E-mail: hollidayca@missouri.edu [Department of Pathology and Anatomical Sciences, M318 Medical Sciences Building, University of Missouri, Columbia, MO 65212 (United States)

2012-03-15

Bone is a dynamic tissue with diverse functions including growth, structural support, pH balance and reproduction. These functions may be compromised in the presence of organopollutants that can alter bone properties. We exposed juvenile diamondback terrapins (Malaclemys terrapin) to 3,3 Prime ,4,4 Prime ,5-pentachlorobiphenyl (PCB 126), a ubiquitous anthropogenic organochlorine, and measured organic content, apparent bone mineral density (aBMD) using radiography and computed tomography, and quantified bone microstructure using histological preparations of femora. PCB-exposed terrapins were smaller in total size. Skulls of exposed animals had a higher organic content and a skeletal phenotype more typical of younger animals. The femora of exposed individuals had significantly reduced aBMD and significantly more cortical area occupied by non-bone. Because bone is an integral component of physiology, the observed skeletal changes can have far-reaching impacts on feeding and locomotor performance, calcium reserves and ultimately life history traits and reproductive success. Additionally, we caution that measurements of bone morphology, density, and composition from field-collected animals need to account not only for relatedness and age, but also environmental pollutants.

Co-exposure to an ortho-substituted PCB (PCB 153) and methylmercury enhances developmental neurotoxic effects

Energy Technology Data Exchange (ETDEWEB)

Fischer, C.; Fredriksson, A.; Eriksson, P. [Dept. Environment. Toxicol., Uppsala Univ. (Sweden)

2004-09-15

In our environment there are innumerable hazardous contaminants. Many of these compounds are the well-known persistent organic pollutants (POPs) like PCB and DDT. Another persistent agent in our environment is methylmercury (MeHg). These agents are known to be neurotoxic in laboratory animals and humans. Fetuses and neonates are known to be high-risk groups for exposure to these agents. A naturally occurring circumstance is the exposure to a combination of different persistent compounds. The knowledge of interaction between different toxic agents during development is sparse. In several studies we have shown that low-dose exposure of environmental toxic agents such as PCBs, DDT, BFRs (brominated flame retardants) as well as well-known neurotoxic agents such as nicotine, organophosphorous compounds and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), during the ''BGS'', in neonatal mice can lead to disruption of the adult brain function, and to an increased susceptibility to toxic agents as adults. Our studies concerning developmental neurotoxic effects after neonatal exposure to single PCB congeners have shown that some orthosubstituted PCBs (such as PCB 28, PCB 52, PCB 153) and some co-planar PCBs (such as PCB 77, PCB 126, PCB 169) cause derangement of adult behaviour that can worsen with age. Furthermore, the cholinergic receptors in the brain were also found to be affected8. Just recently we have seen that neonatal co-exposure to an ortho-substituted PCB, 2,2',5,5'-tetrachlorobiphenyl (PCB 52), together with a brominated flame retardant, 2,2',4,4',5-pentabromodiphenylether (PBDE 99), can enhance developmental neurotoxic effects when the exposure occurs during a critical stage of neonatal brain development. The present study was carried out in order to see whether PCB and MeHg could interact to cause enhanced developmental neurotoxic effects on spontaneous behaviour and habituation capability when given to neonatal mice.

Molecular mechanisms of 3,3′4,4′,5-pentachlorobiphenyl-induced epithelial-mesenchymal transition in human hepatocellular carcinoma cells

International Nuclear Information System (INIS)

Song, Li; Guo, Linlin; Li, Zhuoyu

2017-01-01

Polychlorinated biphenyls (PCBs) are classic persistent organic pollutants (POPs). Many studies have found a positive association between the progression of hepatocellular carcinoma (HCC) and PCBs exposure. However, the influence of PCBs on epithelial-mesenchymal transition (EMT) of HCC remains to be unclear. In this study, we explored the effect of PCB126 on EMT in HCC cells and its underlying mechanisms. The data showed that PCB126, exposing both Bel-7402 and SMMC-7721 cells for 48 h, promoted EMT that was demonstrated by E-cadherin repression, up-regulation of N-cadherin and vimentin, and morphological alteration. We found that signal transducer and activator of transcription 3 (STAT3)/Snail1 signaling was activated after PCB126 exposure, and the addition of STAT3 inhibitor WP1066 blocked PCB126-induced down-regulation of E-cadherin as well as up-regulation of N-cadherin and vimentin. Moreover, PCB126 exposure increased pyruvate kinase M2 (PKM2) expression and its nuclear translocation, whereas treatment with PKM2 shRNA suppressed the activation of STAT3/Snail1 signaling and the alternation of EMT-related molecules (E-cadherin, N-cadherin and vimentin). Furthermore, this study indicated estrogen receptor (ER) and aryl hydrocarbon receptor (AhR) were involved in PCB126-induced effects on PKM2, STAT3/Snail1 signaling and EMT by according treatment using ER inhibitor ICI and AhR shRNA. Notably, PCB126-increased reactive oxygen species (ROS) production via AhR is associated with activation of PKM2/STAT3/Snail1 cascades and contributes to EMT. Taken together, these results indicated that PCB126 promotes EMT process of HCC cells via PKM2/STAT3/Snail1 signaling which is mediated by ER and AhR. - Highlights: • PCB126 promotes epithelial-mesenchymal transition of HCC cells. • PCB126 regulates EMT through the activation of STAT3/Snail1 signaling. • PKM2 is responsible for PCB126-induced activation of STAT3/Snail1 signaling. • AhR-induced ROS generation regulates

Molecular mechanisms of 3,3′4,4′,5-pentachlorobiphenyl-induced epithelial-mesenchymal transition in human hepatocellular carcinoma cells

Energy Technology Data Exchange (ETDEWEB)

Song, Li; Guo, Linlin [Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan 030006 (China); Li, Zhuoyu, E-mail: lzy@sxu.edu.cn [Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan 030006 (China); College of Life Science, Zhejiang Chinese Medical University, Hangzhou 310053 (China)

2017-05-01

Polychlorinated biphenyls (PCBs) are classic persistent organic pollutants (POPs). Many studies have found a positive association between the progression of hepatocellular carcinoma (HCC) and PCBs exposure. However, the influence of PCBs on epithelial-mesenchymal transition (EMT) of HCC remains to be unclear. In this study, we explored the effect of PCB126 on EMT in HCC cells and its underlying mechanisms. The data showed that PCB126, exposing both Bel-7402 and SMMC-7721 cells for 48 h, promoted EMT that was demonstrated by E-cadherin repression, up-regulation of N-cadherin and vimentin, and morphological alteration. We found that signal transducer and activator of transcription 3 (STAT3)/Snail1 signaling was activated after PCB126 exposure, and the addition of STAT3 inhibitor WP1066 blocked PCB126-induced down-regulation of E-cadherin as well as up-regulation of N-cadherin and vimentin. Moreover, PCB126 exposure increased pyruvate kinase M2 (PKM2) expression and its nuclear translocation, whereas treatment with PKM2 shRNA suppressed the activation of STAT3/Snail1 signaling and the alternation of EMT-related molecules (E-cadherin, N-cadherin and vimentin). Furthermore, this study indicated estrogen receptor (ER) and aryl hydrocarbon receptor (AhR) were involved in PCB126-induced effects on PKM2, STAT3/Snail1 signaling and EMT by according treatment using ER inhibitor ICI and AhR shRNA. Notably, PCB126-increased reactive oxygen species (ROS) production via AhR is associated with activation of PKM2/STAT3/Snail1 cascades and contributes to EMT. Taken together, these results indicated that PCB126 promotes EMT process of HCC cells via PKM2/STAT3/Snail1 signaling which is mediated by ER and AhR. - Highlights: • PCB126 promotes epithelial-mesenchymal transition of HCC cells. • PCB126 regulates EMT through the activation of STAT3/Snail1 signaling. • PKM2 is responsible for PCB126-induced activation of STAT3/Snail1 signaling. • AhR-induced ROS generation regulates

γIrradiation induced formation of PCB-solvent adducts in aliphatic solvents

International Nuclear Information System (INIS)

Lepine, F.; Milot, S.; Gagne, N.

1990-01-01

γIrradiation induced formation of PCB-solvent adducts was investigated as a model for PCB residues in irradiated food. Formation of cyclohexyl adducts of PCBs was found to be significant when pure PCB congeners and Aroclor mixture were irradiated in cyclohexane and cyclohexene. Reaction pathways were investigated, and the effects of oxygen and electron scavenger were studied

Interacting influence of potassium and polychlorinated biphenyl on cortisol and aldosterone biosynthesis

International Nuclear Information System (INIS)

Li, L.-A.; Lin, Tsu-Chun Emma

2007-01-01

Giving human adrenocortical H295R cells 14 mM KCl for 24 h significantly induced not only aldosterone biosynthesis but also cortisol biosynthesis. Pre-treating the cells with polychlorinated biphenyl 126 (PCB126) further increased potassium-induced aldosterone and cortisol productions in a dose-dependent manner, but all examined concentrations of PCB126 had little effect on the yields of precursor steroids progesterone and 17-OH-progesterone. Subsequent examinations revealed that CYP11B1 and CYP11B2 genes, responsible for the respective final steps of the cortisol and aldosterone biosynthetic pathways, exhibited increased responsiveness to PCB126 under high potassium. While 10 -5 M PCB126 was needed to induce a significant increase in the basal mRNA abundance of either gene, PCB126 could enhance potassium-induced mRNA expression of CYP11B1 at 10 -7 M and CYP11B2 at 10 -9 M. Actually, potassium and PCB126 synergistically upregulated mRNA expression of both genes. Potassium raised the transcriptional rates of CYP11B1 and CYP11B2 probably through a conserved Ad5 cis-element, whereas PCB126 appeared to regulate these two genes at the post-transcriptional level. Positive potassium-PCB126 synergism was also detected in CYP11B2 enzyme activity estimated by aldosterone/progesterone ratio. In contrast, potassium and PCB126 increased CYP11B1 enzyme activity or cortisol/17-OH-progesterone ratio additively. Moreover, potassium improved the time effect of PCB126 on gene expression and enzyme activity of CYP11B2, but not the PCB126 time response of CYP11B1. These data demonstrated that potassium differentially enhanced the potency of PCB126 to induce CYP11B1- and CYP11B2-mediated steroidogenesis

Intestinal exposure to PCB 153 induces inflammation via the ATM/NEMO pathway.

Science.gov (United States)

Phillips, Matthew C; Dheer, Rishu; Santaolalla, Rebeca; Davies, Julie M; Burgueño, Juan; Lang, Jessica K; Toborek, Michal; Abreu, Maria T

2018-01-15

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that adversely affect human health. PCBs bio-accumulate in organisms important for human consumption. PCBs accumulation in the body leads to activation of the transcription factor NF-κB, a major driver of inflammation. Despite dietary exposure being one of the main routes of exposure to PCBs, the gut has been widely ignored when studying the effects of PCBs. We investigated the effects of PCB 153 on the intestine and addressed whether PCB 153 affected intestinal permeability or inflammation and the mechanism by which this occurred. Mice were orally exposed to PCB 153 and gut permeability was assessed. Intestinal epithelial cells (IECs) were collected and evaluated for evidence of genotoxicity and inflammation. A human IEC line (SW480) was used to examine the direct effects of PCB 153 on epithelial function. NF-кB activation was measured using a reporter assay, DNA damage was assessed, and cytokine expression was ascertained with real-time PCR. Mice orally exposed to PCB 153 had an increase in intestinal permeability and inflammatory cytokine expression in their IECs; inhibition of NF-кB ameliorated both these effects. This inflammation was associated with genotoxic damage and NF-кB activation. Exposure of SW480 cells to PCB 153 led to similar effects as seen in vivo. We found that activation of the ATM/NEMO pathway by genotoxic stress was upstream of NF-kB activation. These results demonstrate that oral exposure to PCB 153 is genotoxic to IECs and induces downstream inflammation and barrier dysfunction in the intestinal epithelium. Copyright © 2017 Elsevier Inc. All rights reserved.

Chronic treatment with polychlorinated biphenyls (PCB) during pregnancy and lactation in the rat

International Nuclear Information System (INIS)

Cocchi, Daniela; Tulipano, Giovanni; Colciago, Alessandra; Sibilia, Valeria; Pagani, Francesca; Vigano, Daniela; Rubino, Tiziana; Parolaro, Daniela; Bonfanti, Patrizia; Colombo, Anita; Celotti, Fabio

2009-01-01

Polychlorinated biphenyls (PCBs) are pollutants detected in animal tissues and breast milk. The experiments described in the present paper were aimed at evaluating whether the four PCB congeners most abundant in animal tissues (PCB-138, -153, -180 and -126), administered since fetal life till weaning, can induce long-term alterations of GH-axis activity and bone mass in the adult rat. We measured PCB accumulation in rat brain and liver, somatic growth, pituitary GH expression and plasma hormone concentrations at different ages. Finally, we studied hypothalamic somatostatin expression and bone structure in adulthood, following long-term PCB exposure. Dams were treated during pregnancy from GD15 to GD19 and during breast-feeding. A constant reduction of the growth rate in both male and female offspring from weaning to adulthood was observed in exposed animals. Long-lasting alterations on hypothalamic-pituitary GH axis were indeed observed in PCB-exposed rats in adulthood: increased somatostatin expression in hypothalamic periventricular nucleus (both males and females) and lateral arcuate nucleus (males, only) and decreased GH mRNA levels in the pituitary of male rats. Plasma IGF-1 levels were higher in PCB-exposed male and female animals as compared with controls at weaning and tended to be higher at PN60. Plasma testosterone and thyroid hormone concentrations were not significantly affected by exposure to PCBs. In adulthood, PCBs caused a significant reduction of bone mineral content and cortical bone thickness of tibiae in male rat joint to increased width of the epiphyseal cartilage disk. In conclusion, the developmental exposure to the four selected PCB compounds used in the present study induced far-reaching effects in the adult offspring, the male rats appearing more sensitive than females.

Atropisomers of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) exhibit stereoselective effects on activation of nuclear receptors in vitro.

Science.gov (United States)

Pěnčíková, Kateřina; Brenerová, Petra; Svržková, Lucie; Hrubá, Eva; Pálková, Lenka; Vondráček, Jan; Lehmler, Hans-Joachim; Machala, Miroslav

2017-11-09

PCB 136 is an environmentally relevant chiral PCB congener, which has been found in vivo to be present in form of rotational isomers (atropisomers). Its atropselective biotransformation or neurotoxic effects linked with sensitization of ryanodine receptor suggest that it might interact also with other intracellular receptors in a stereospecific manner. However, possible atropselective effects of PCB 136 on nuclear receptor transactivation remain unknown. Therefore, in this study, atropselective effects of PCB 136 on nuclear receptors controlling endocrine signaling and/or expression of xenobiotic and steroid hormone catabolism were investigated. PCB136 atropisomers were found to exert differential effects on estrogen receptor (ER) activation; (+)-PCB 136 was estrogenic, while (-)-PCB 136 was antiestrogenic. In contrast, inhibition of androgen receptor (AR) activity was not stereospecific. Both PCB136 stereoisomers induced the constitutive androgen receptor (CAR)-dependent gene expression; however, no significant stereospecificity of PCB 136 atropisomers was observed. PCB136 was a partial inducer of the pregnane X receptor (PXR)-dependent gene expression. Here, (-)-PCB 136 was a significantly more potent inducer of PXR activity than (+)-PCB 136. Taken together, the present results indicate that at least two nuclear receptors participating in endocrine regulation or metabolism, ER and PXR, could be regulated in an atropselective manner by chiral PCB 136. The enantioselective enrichment of PCB atropisomers in animal and human tissues may thus have significant consequences for endocrine-disrupting effects of chiral ortho-substituted PCB congeners.

Resveratrol via sirtuin-1 downregulates RE1-silencing transcription factor (REST) expression preventing PCB-95-induced neuronal cell death

International Nuclear Information System (INIS)

Guida, Natascia; Laudati, Giusy; Anzilotti, Serenella; Secondo, Agnese; Montuori, Paolo; Di Renzo, Gianfranco; Canzoniero, Lorella M.T.; Formisano, Luigi

2015-01-01

Resveratrol (3,5,4′-trihydroxystilbene) (RSV), a polyphenol widely present in plants, exerts a neuroprotective function in several neurological conditions; it is an activator of class III histone deacetylase sirtuin1 (SIRT1), a crucial regulator in the pathophysiology of neurodegenerative diseases. By contrast, the RE1-silencing transcription factor (REST) is involved in the neurotoxic effects following exposure to polychlorinated biphenyl (PCB) mixture A1254. The present study investigated the effects of RSV-induced activation of SIRT1 on REST expression in SH-SY5Y cells. Further, we investigated the possible relationship between the non-dioxin-like (NDL) PCB-95 and REST through SIRT1 to regulate neuronal death in rat cortical neurons. Our results revealed that RSV significantly decreased REST gene and protein levels in a dose- and time-dependent manner. Interestingly, overexpression of SIRT1 reduced REST expression, whereas EX-527, an inhibitor of SIRT1, increased REST expression and blocked RSV-induced REST downregulation. These results suggest that RSV downregulates REST through SIRT1. In addition, RSV enhanced activator protein 1 (AP-1) transcription factor c-Jun expression and its binding to the REST promoter gene. Indeed, c-Jun knockdown reverted RSV-induced REST downregulation. Intriguingly, in SH-SY5Y cells and rat cortical neurons the NDL PCB-95 induced necrotic cell death in a concentration-dependent manner by increasing REST mRNA and protein expression. In addition, SIRT1 knockdown blocked RSV-induced neuroprotection in rat cortical neurons treated with PCB-95. Collectively, these results indicate that RSV via SIRT1 activates c-Jun, thereby reducing REST expression in SH-SY5Y cells under physiological conditions and blocks PCB-95-induced neuronal cell death by activating the same SIRT1/c-Jun/REST pathway. - Highlights: • Resveratrol via SIRT1/c-Jun downregulates REST mRNA and protein in SH-SY5Y cells. • Non-dioxin-like (NDL) PCB-95 is cytotoxic to

Resveratrol via sirtuin-1 downregulates RE1-silencing transcription factor (REST) expression preventing PCB-95-induced neuronal cell death

Energy Technology Data Exchange (ETDEWEB)

Guida, Natascia [IRCSS SDN, Naples 80131 (Italy); Laudati, Giusy [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Anzilotti, Serenella [IRCSS SDN, Naples 80131 (Italy); Secondo, Agnese [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Montuori, Paolo [Department of Public Health, ‘Federico II’ University of Naples, Naples (Italy); Di Renzo, Gianfranco [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Canzoniero, Lorella M.T. [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Division of Pharmacology, Department of Science and Technology, University of Sannio, Via Port' Arsa 11, 82100 Benevento (Italy); Formisano, Luigi, E-mail: cformisa@unisannio.it [Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini, 5, 80131 Naples (Italy); Division of Pharmacology, Department of Science and Technology, University of Sannio, Via Port' Arsa 11, 82100 Benevento (Italy)

2015-11-01

Resveratrol (3,5,4′-trihydroxystilbene) (RSV), a polyphenol widely present in plants, exerts a neuroprotective function in several neurological conditions; it is an activator of class III histone deacetylase sirtuin1 (SIRT1), a crucial regulator in the pathophysiology of neurodegenerative diseases. By contrast, the RE1-silencing transcription factor (REST) is involved in the neurotoxic effects following exposure to polychlorinated biphenyl (PCB) mixture A1254. The present study investigated the effects of RSV-induced activation of SIRT1 on REST expression in SH-SY5Y cells. Further, we investigated the possible relationship between the non-dioxin-like (NDL) PCB-95 and REST through SIRT1 to regulate neuronal death in rat cortical neurons. Our results revealed that RSV significantly decreased REST gene and protein levels in a dose- and time-dependent manner. Interestingly, overexpression of SIRT1 reduced REST expression, whereas EX-527, an inhibitor of SIRT1, increased REST expression and blocked RSV-induced REST downregulation. These results suggest that RSV downregulates REST through SIRT1. In addition, RSV enhanced activator protein 1 (AP-1) transcription factor c-Jun expression and its binding to the REST promoter gene. Indeed, c-Jun knockdown reverted RSV-induced REST downregulation. Intriguingly, in SH-SY5Y cells and rat cortical neurons the NDL PCB-95 induced necrotic cell death in a concentration-dependent manner by increasing REST mRNA and protein expression. In addition, SIRT1 knockdown blocked RSV-induced neuroprotection in rat cortical neurons treated with PCB-95. Collectively, these results indicate that RSV via SIRT1 activates c-Jun, thereby reducing REST expression in SH-SY5Y cells under physiological conditions and blocks PCB-95-induced neuronal cell death by activating the same SIRT1/c-Jun/REST pathway. - Highlights: • Resveratrol via SIRT1/c-Jun downregulates REST mRNA and protein in SH-SY5Y cells. • Non-dioxin-like (NDL) PCB-95 is cytotoxic to

CD36 participates in PrP(106-126-induced activation of microglia.

Directory of Open Access Journals (Sweden)

Mohammed Kouadir

Full Text Available Microglial activation is a characteristic feature of the pathogenesis of prion diseases. The molecular mechanisms that underlie prion-induced microglial activation are not very well understood. In the present study, we investigated the role of the class B scavenger receptor CD36 in microglial activation induced by neurotoxic prion protein (PrP fragment 106-126 (PrP(106-126. We first examined the time course of CD36 mRNA expression upon exposure to PrP(106-126 in BV2 microglia. We then analyzed different parameters of microglial activation in PrP(106-126-treated cells in the presence or not of anti-CD36 monoclonal antibody (mAb. The cells were first incubated for 1 h with CD36 monoclonal antibody to block the CD36 receptor, and were then treated with neurotoxic prion peptides PrP(106-126. The results showed that PrP(106-126 treatment led to a rapid yet transitory increase in the mRNA expression of CD36, upregulated mRNA and protein levels of proinflammatory cytokines (IL-1β, IL-6 and TNF-α, increased iNOS expression and nitric oxide (NO production, stimulated the activation of NF-κB and caspase-1, and elevated Fyn activity. The blockade of CD36 had no effect on PrP(106-126-stimulated NF-κB activation and TNF-α protein release, abrogated the PrP(106-126-induced iNOS stimulation, downregulated IL-1β and IL-6 expression at both mRNA and protein levels as well as TNF-α mRNA expression, decreased NO production and Fyn phosphorylation, reduced caspase-1 cleavage induced by moderate PrP(106-126-treatment, but had no effect on caspase-1 activation after treatment with a high concentration of PrP(106-126. Together, these results suggest that CD36 is involved in PrP(106-126-induced microglial activation and that the participation of CD36 in the interaction between PrP(106-126 and microglia may be mediated by Src tyrosine kinases. Our findings provide new insights into the mechanisms underlying the activation of microglia by neurotoxic prion peptides

Polychlorinated Biphenyls (PCB) Residue Effects Database

Data.gov (United States)

U.S. Environmental Protection Agency — The PCB Residue Effects (PCBRes) Database was developed to assist scientists and risk assessors in correlating PCB and dioxin-like compound residues with toxic...

PCB eksponering i Farum Midtpunkt

DEFF Research Database (Denmark)

Meyer, Harald William; Frederiksen, Marie; Ebbehøj, Niels Erik

I marts og april 2011 blev i alt 104 lejligheder og 289 beboere fra Farum Midtpunkt undersøgt for niveauer af PolyChlorerede Biphenyler (PCB) i henholdsvis fuger og indeluft i lejligheder-ne, og i blodplasma. Til analyserne i denne rapport indgik 273 beboere, 139 fra PCB-forurenede lejligheder og...... 134 fra ikke-forurenede lejligheder. Der blev indsamlet luftprøver fra 83 forure-nede og 21 ikke-forurenede lejligheder og fugeprøver fra 20 forurenede lejligheder. Ni ud af 24 målte PCB-kongenere var under detektionsgrænsen i luften, inkl. de to mest toksiske kongenere nr. 126 og 169. For de...... forurenede lejlig-heder, undtagen for nr. 183 og 190, samt for nr. 182 som alle lå under detektionsgrænsen. For ni ud af tolv dioxin-lignende PCB-forbindelser var alle, eller næsten alle prøver under detektions-grænsen. For nr. 105 og 118 sås signifikant højere niveau blandt eksponerede. Mænd havde et lidt...

Resveratrol via sirtuin-1 downregulates RE1-silencing transcription factor (REST) expression preventing PCB-95-induced neuronal cell death.

Science.gov (United States)

Guida, Natascia; Laudati, Giusy; Anzilotti, Serenella; Secondo, Agnese; Montuori, Paolo; Di Renzo, Gianfranco; Canzoniero, Lorella M T; Formisano, Luigi

2015-11-01

Resveratrol (3,5,4'-trihydroxystilbene) (RSV), a polyphenol widely present in plants, exerts a neuroprotective function in several neurological conditions; it is an activator of class III histone deacetylase sirtuin1 (SIRT1), a crucial regulator in the pathophysiology of neurodegenerative diseases. By contrast, the RE1-silencing transcription factor (REST) is involved in the neurotoxic effects following exposure to polychlorinated biphenyl (PCB) mixture A1254. The present study investigated the effects of RSV-induced activation of SIRT1 on REST expression in SH-SY5Y cells. Further, we investigated the possible relationship between the non-dioxin-like (NDL) PCB-95 and REST through SIRT1 to regulate neuronal death in rat cortical neurons. Our results revealed that RSV significantly decreased REST gene and protein levels in a dose- and time-dependent manner. Interestingly, overexpression of SIRT1 reduced REST expression, whereas EX-527, an inhibitor of SIRT1, increased REST expression and blocked RSV-induced REST downregulation. These results suggest that RSV downregulates REST through SIRT1. In addition, RSV enhanced activator protein 1 (AP-1) transcription factor c-Jun expression and its binding to the REST promoter gene. Indeed, c-Jun knockdown reverted RSV-induced REST downregulation. Intriguingly, in SH-SY5Y cells and rat cortical neurons the NDL PCB-95 induced necrotic cell death in a concentration-dependent manner by increasing REST mRNA and protein expression. In addition, SIRT1 knockdown blocked RSV-induced neuroprotection in rat cortical neurons treated with PCB-95. Collectively, these results indicate that RSV via SIRT1 activates c-Jun, thereby reducing REST expression in SH-SY5Y cells under physiological conditions and blocks PCB-95-induced neuronal cell death by activating the same SIRT1/c-Jun/REST pathway. Copyright © 2015 Elsevier Inc. All rights reserved.

Metabolism of 2,2′,3,3′,6,6′-Hexachlorobiphenyl (PCB 136) Atropisomers in Tissue Slices from Phenobarbital or Dexamethasone-Induced Rats is Sex-Dependent

Science.gov (United States)

Wu, Xianai; Kania-Korwel, Izabela; Chen, Hao; Stamou, Marianna; Dammanahalli, Karigowda J.; Duffel, Michael; Lein, Pamela J.; Lehmler, Hans-Joachim

2013-01-01

Chiral polychlorinated biphenyls (PCBs) such as PCB 136 enantioselectively sensitize the ryanodine receptor (RyR). In light of recent evidence that PCBs cause developmental neurotoxicity via RyR-dependent mechanisms, this suggests that enantioselective PCB metabolism may influence the developmental neurotoxicity of chiral PCBs. However, enantioselective disposition of PCBs has not been fully characterized.The effect of sex and cytochrome P450 (P450) enzyme induction on the enantioselective metabolism of PCB 136 was studied using liver tissue slices prepared from naïve control (CTL), phenobarbital (PB; CYP2B inducer) or dexamethasone (DEX; CYP3A inducer) pretreated adult Sprague-Dawley rats. PCB 136 metabolism was also examined in hippocampal slices derived from untreated rat pups.In liver tissue slices, hydroxylated PCB (OH-PCB) profiles depended on sex and inducer pretreatment, and OH-PCB levels followed the rank orders male > female and PB > DEX > CTL. In contrast, the enantiomeric enrichment of PCB 136 and its metabolites was independent of sex and inducer pretreatment. Only small amounts of PCB 136 partitioned into hippocampal tissue slices and no OH-PCB metabolites were detected.Our results suggest that enantioselective metabolism, sex and induction status of P450 enzymes in the liver may modulate the neurotoxic outcomes of developmental exposure to chiral PCBs. PMID:23581876

Regulation of pregnane-X-receptor, CYP3A and P-glycoprotein genes in the PCB-resistant killifish (Fundulus heteroclitus) population from New Bedford Harbor

International Nuclear Information System (INIS)

Gräns, Johanna; Wassmur, Britt; Fernández-Santoscoy, María; Zanette, Juliano; Woodin, Bruce R.; Karchner, Sibel I.; Nacci, Diane E.; Champlin, Denise; Jayaraman, Saro; Hahn, Mark E.; Stegeman, John J.; Celander, Malin C.

2015-01-01

Highlights: • Basal levels of PXR and Pgp mRNA are lower in liver of fish from NBH than from SC. • Hepatic PXR, CYP3A and Pgp mRNA levels are induced by PCB in fish from NBH. • Both non-dioxin-like and dioxin-like PCBs induce PXR, CYP3A and Pgp in NBH fish. • Branchial PXR and CYP3A mRNA levels are induced by PCB 126 in fish from SC. • There is possible cross-talk between AhR and PXR signaling in killifish. - Abstract: Killifish survive and reproduce in the New Bedford Harbor (NBH) in Massachusetts (MA), USA, a site severely contaminated with polychlorinated biphenyls (PCBs) for decades. Levels of 22 different PCB congeners were analyzed in liver from killifish collected in 2008. Concentrations of dioxin-like PCBs in liver of NBH killifish were ∼400 times higher, and the levels of non-dioxin-like PCBs ∼3000 times higher than in killifish from a reference site, Scorton Creek (SC), MA. The NBH killifish are known to be resistant to the toxicity of dioxin-like compounds and to have a reduced aryl hydrocarbon receptor (AhR) signaling response. Little is known about the responses of these fish to non-dioxin-like PCBs, which are at extraordinarily high levels in NBH fish. In mammals, some non-dioxin-like PCB congeners act through nuclear receptor 1I2, the pregnane-X-receptor (PXR). To explore this pathway in killifish, a PXR cDNA was sequenced and its molecular phylogenetic relationship to other vertebrate PXRs was determined. Killifish were also collected in 2009 from NBH and SC, and after four months in the laboratory they were injected with a single dose of either the dioxin-like PCB 126 (an AhR agonist) or the non-dioxin-like PCB 153 (a mammalian PXR agonist). Gills and liver were sampled three days after injection and transcript levels of genes encoding PXR, cytochrome P450 3A (CYP3A), P-glycoprotein (Pgp), AhR2 and cytochrome P450 1A (CYP1A) were measured by quantitative PCR. As expected, there was little effect of PCB exposure on mRNA expression of

Regulation of pregnane-X-receptor, CYP3A and P-glycoprotein genes in the PCB-resistant killifish (Fundulus heteroclitus) population from New Bedford Harbor

Energy Technology Data Exchange (ETDEWEB)

Gräns, Johanna; Wassmur, Britt; Fernández-Santoscoy, María [Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, SE 405 30 Gothenburg (Sweden); Zanette, Juliano; Woodin, Bruce R.; Karchner, Sibel I. [Biology Department, MS #32, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States); Nacci, Diane E.; Champlin, Denise; Jayaraman, Saro [Office of Research and Development, National Health and Environmental Effects Research Laboratory, Atlantic Ecology Division, United States Environmental Protection Agency, 27 Tarzwell Drive, Narragansett, RI 02882 (United States); Hahn, Mark E.; Stegeman, John J. [Biology Department, MS #32, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States); Celander, Malin C., E-mail: malin.celander@gu.se [Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, SE 405 30 Gothenburg (Sweden)

2015-02-15

Highlights: • Basal levels of PXR and Pgp mRNA are lower in liver of fish from NBH than from SC. • Hepatic PXR, CYP3A and Pgp mRNA levels are induced by PCB in fish from NBH. • Both non-dioxin-like and dioxin-like PCBs induce PXR, CYP3A and Pgp in NBH fish. • Branchial PXR and CYP3A mRNA levels are induced by PCB 126 in fish from SC. • There is possible cross-talk between AhR and PXR signaling in killifish. - Abstract: Killifish survive and reproduce in the New Bedford Harbor (NBH) in Massachusetts (MA), USA, a site severely contaminated with polychlorinated biphenyls (PCBs) for decades. Levels of 22 different PCB congeners were analyzed in liver from killifish collected in 2008. Concentrations of dioxin-like PCBs in liver of NBH killifish were ∼400 times higher, and the levels of non-dioxin-like PCBs ∼3000 times higher than in killifish from a reference site, Scorton Creek (SC), MA. The NBH killifish are known to be resistant to the toxicity of dioxin-like compounds and to have a reduced aryl hydrocarbon receptor (AhR) signaling response. Little is known about the responses of these fish to non-dioxin-like PCBs, which are at extraordinarily high levels in NBH fish. In mammals, some non-dioxin-like PCB congeners act through nuclear receptor 1I2, the pregnane-X-receptor (PXR). To explore this pathway in killifish, a PXR cDNA was sequenced and its molecular phylogenetic relationship to other vertebrate PXRs was determined. Killifish were also collected in 2009 from NBH and SC, and after four months in the laboratory they were injected with a single dose of either the dioxin-like PCB 126 (an AhR agonist) or the non-dioxin-like PCB 153 (a mammalian PXR agonist). Gills and liver were sampled three days after injection and transcript levels of genes encoding PXR, cytochrome P450 3A (CYP3A), P-glycoprotein (Pgp), AhR2 and cytochrome P450 1A (CYP1A) were measured by quantitative PCR. As expected, there was little effect of PCB exposure on mRNA expression of

Lipid rafts regulate PCB153-induced disruption of occludin and brain endothelial barrier function through protein phosphatase 2A and matrix metalloproteinase-2

Energy Technology Data Exchange (ETDEWEB)

Eum, Sung Yong, E-mail: seum@miami.edu; Jaraki, Dima; András, Ibolya E.; Toborek, Michal

2015-09-15

Occludin is an essential integral transmembrane protein regulating tight junction (TJ) integrity in brain endothelial cells. Phosphorylation of occludin is associated with its localization to TJ sites and incorporation into intact TJ assembly. The present study is focused on the role of lipid rafts in polychlorinated biphenyl (PCB)-induced disruption of occludin and endothelial barrier function. Exposure of human brain endothelial cells to 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB153) induced dephosphorylation of threonine residues of occludin and displacement of occludin from detergent-resistant membrane (DRM)/lipid raft fractions within 1 h. Moreover, lipid rafts modulated the reduction of occludin level through activation of matrix metalloproteinase 2 (MMP-2) after 24 h PCB153 treatment. Inhibition of protein phosphatase 2A (PP2A) activity by okadaic acid or fostriecin markedly protected against PCB153-induced displacement of occludin and increased permeability of endothelial cells. The implication of lipid rafts and PP2A signaling in these processes was further defined by co-immunoprecipitation of occludin with PP2A and caveolin-1, a marker protein of lipid rafts. Indeed, a significant MMP-2 activity was observed in lipid rafts and was increased by exposure to PCB153. The pretreatment of MMP-2 inhibitors protected against PCB153-induced loss of occludin and disruption of lipid raft structure prevented the increase of endothelial permeability. Overall, these results indicate that lipid raft-associated processes, such as PP2A and MMP-2 activation, participate in PCB153-induced disruption of occludin function in brain endothelial barrier. This study contributes to a better understanding of the mechanisms leading to brain endothelial barrier dysfunction in response to exposure to environmental pollutants, such as ortho-substituted PCBs. - Highlights: • PCB153 disturbed human brain endothelial barrier through disruption of occludin. • Lipid raft-associated PP

PCB dechlorination in anaerobic soil slurry reactors

International Nuclear Information System (INIS)

Klasson, K.T.; Evans, B.S.

1993-01-01

Many industrial locations, including the US Department of Energy's, have identified needs for treatment of polychlorinated biphenyl (PCB) wastes and remediation of PCB-contaminated sites. Biodegradation of PCBs is a potentially effective technology for the treatment of PCB-contaminated soils and sludges, including mixed wastes; however, a practical remediation technology has not yet been demonstrated. In laboratory experiments, soil slurry bioreactors inoculated with microorganisms extracted from PCB-contaminated sediments from the Hudson River have been used to obtain anaerobic dechlorination of PCBS. The onset of dechlorination activity can be accelerated by addition of nutritional amendments and inducers. After 15 weeks of incubation with PCB-contaminated soil and nutrient solution, dechlorination has been observed under several working conditions. The best results show that the average chlorine content steadily dropped from 4.3 to 3.5 chlorines per biphenyl over a 15-week period

Genetic variation in the CYP1A1 gene is related to circulating PCB118 levels in a population-based sample

Energy Technology Data Exchange (ETDEWEB)

Lind, Lars [Department of Medical Sciences, Cardiovascular Epidemiology, Uppsala University, Uppsala (Sweden); Penell, Johanna [Department of Medical Sciences, Occupational and Environmental Medicine, Uppsala University, Uppsala (Sweden); Syvänen, Anne-Christine; Axelsson, Tomas [Department of Medical Sciences, Molecular Medicine and Science for Life Laboratory, Uppsala University, Uppsala (Sweden); Ingelsson, Erik [Department of Medical Sciences, Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala (Sweden); Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford (United Kingdom); Morris, Andrew P.; Lindgren, Cecilia [Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford (United Kingdom); Salihovic, Samira; Bavel, Bert van [MTM Research Centre, School of Science and Technology, Örebro University, Örebro (Sweden); Lind, P. Monica, E-mail: monica.lind@medsci.uu.se [Department of Medical Sciences, Occupational and Environmental Medicine, Uppsala University, Uppsala (Sweden)

2014-08-15

Several of the polychlorinated biphenyls (PCBs), i.e. the dioxin-like PCBs, are known to induce the P450 enzymes CYP1A1, CYP1A2 and CYP1B1 by activating the aryl hydrocarbon receptor (Ah)-receptor. We evaluated if circulating levels of PCBs in a population sample were related to genetic variation in the genes encoding these CYPs. In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (1016 subjects all aged 70), 21 SNPs in the CYP1A1, CYP1A2 and CYP1B1 genes were genotyped. Sixteen PCB congeners were analysed by high-resolution chromatography coupled to high-resolution mass spectrometry (HRGC/ HRMS). Of the investigated relationships between SNPs in the CYP1A1, CYP1A2 and CYP1B1 and six PCBs (congeners 118, 126, 156, 169, 170 and 206) that captures >80% of the variation of all PCBs measured, only the relationship between CYP1A1 rs2470893 was significantly related to PCB118 levels following strict adjustment for multiple testing (p=0.00011). However, there were several additional SNPs in the CYP1A2 and CYP1B1 that showed nominally significant associations with PCB118 levels (p-values in the 0.003–0.05 range). Further, several SNPs in the CYP1B1 gene were related to both PCB156 and PCB206 with p-values in the 0.005–0.05 range. Very few associations with p<0.05 were seen for PCB126, PCB169 or PCB170. Genetic variation in the CYP1A1 was related to circulating PCB118 levels in the general elderly population. Genetic variation in CYP1A2 and CYP1B1 might also be associated with other PCBs. - Highlights: • We studied the relationship between PCBs and the genetic variation in the CYP genes. • Cross sectional data from a cohort of elderly were analysed. • The PCB levels were evaluated versus 21 SNPs in three CYP genes. • PCB 118 was related to variation in the CYP1A1 gene.

EROD induction by environmental contaminants in avian embryo livers

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Brunstroem, B.; Halldin, K. [Department of Environmental Toxicology, Uppsala University, Norbyvaegen 18A SE-752 36, Uppsala (Sweden)

1998-11-01

The CYP1A (EROD)-inducing potencies of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3minutes or feet,4,4minutes or feet,5-pentachlorobiphenyl (PCB126) and benzo(k)fluoranthene (B(k)F) were studied in avian embryo livers. TCDD and PCB126 proved to be much more potent as inducers in the chicken than in the other species examined. This finding is consistent with a considerably higher sensitivity of the chicken compared with a number of other avian species to the embryotoxic effects of these compounds. Furthermore, the relative potencies of the tested Ah receptor agonists as CYP1A inducers differed substantially between species. B(k)F and PCB126 showed similar induction potencies in domestic duck embryos, whereas PCB126 is much more potent than B(k)F in the chicken. Also, the potency of PCB126,relative to that of TCDD, was much lower in quail embryo liver in vitro than in chicken embryo liver. Thus, there are large interspecific differences in birds in the sensitivity to CYP1A inducers and furthermore, the relative potencies of these compounds may differ substantially between species. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

EROD induction by environmental contaminants in avian embryo livers

International Nuclear Information System (INIS)

Brunstroem, B.; Halldin, K.

1998-01-01

The CYP1A (EROD)-inducing potencies of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3minutes or feet,4,4minutes or feet,5-pentachlorobiphenyl (PCB126) and benzo(k)fluoranthene (B(k)F) were studied in avian embryo livers. TCDD and PCB126 proved to be much more potent as inducers in the chicken than in the other species examined. This finding is consistent with a considerably higher sensitivity of the chicken compared with a number of other avian species to the embryotoxic effects of these compounds. Furthermore, the relative potencies of the tested Ah receptor agonists as CYP1A inducers differed substantially between species. B(k)F and PCB126 showed similar induction potencies in domestic duck embryos, whereas PCB126 is much more potent than B(k)F in the chicken. Also, the potency of PCB126, relative to that of TCDD, was much lower in quail embryo liver in vitro than in chicken embryo liver. Thus, there are large interspecific differences in birds in the sensitivity to CYP1A inducers and furthermore, the relative potencies of these compounds may differ substantially between species. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Foetal uptake of coplanar polychlorinated biphenyl (PCB) congeners in mice

International Nuclear Information System (INIS)

Darnerud, P.O.; Sinjari, T.; Joensson, C.J.

1996-01-01

Earlier studies have shown that the Ah-receptor binding polychlorinated biphenyl (PCB) congener 3,3',4,4'-tetrachlorobiphenyl (IUPAC number CB-77) accumulated as hydroxy and methylsulphone metabolites in late gestational mice foetuses. In the present paper the foetal accumulation potential in mice of other dioxin-like PCB congeners was studied: 3,3'4,4',4-pentachlorobiphenyl, 3,3'4,4'5,5'-hexachlorobiphenyl and 2,3,3',4,4'-pentachlorobiphenyl (IUPAC numbers CB-126, CB-169, CB-105, to some extent dioxin-like) were compared to results of CB-77 (all congeners 14 C-labelled and in equimolar doses (2.0 μmol/kg body wt.)). CB-77 resulted in the comparatively strongest foetal 14 C-accumulation, when measured in plasma or whole body homogenate four days after administration (day 17 of pregnancy); the plasma 14 C-values (calculated as pmol/g wet wt.) were 760, 130, 60 and 40 for CB-77, -126, 105 and -169, respectively, and the CB-77 derived radioactivity in the foetal compartment was 3.6% of administered dose (i.e. a considerable portion of the remaining maternal body radioactivity). Thin-layer chromatography (TLC) results, suggesting extensive CB-77 metabolism and foetal metabolite uptake, support earlier findings. The effects of CB-77 and CB-169 on foetal 7-ethoxyresorufin-O-deethylase (EROD) activities (day 17 of gestation; two days after 5 mg/kg body wt. dose (14.0-17.0 μmol/kg body wt.)) was about 20 times lower than of CB-126. In the dam, high radioactivity levels were observed int he liver and fat (highest concentrations found in CB-126 and CB-105, respectively). Strain comparison - foetal 14 C-uptake (four days after administration of CB-77) in C57BL mice was almost five times higher than in NMRI - may be correlated to earlier observed differences in EROD activities between these strains. The present results indicate that congener and strain differences exist regarding both foetal and maternal distribution patterns of coplanar PCB congeners and point out the

NADPH oxidase and lipid raft-associated redox signaling are required for PCB153-induced upregulation of cell adhesion molecules in human brain endothelial cells

International Nuclear Information System (INIS)

Eum, Sung Yong; Andras, Ibolya; Hennig, Bernhard; Toborek, Michal

2009-01-01

Exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCBs), can lead to chronic inflammation and the development of vascular diseases. Because cell adhesion molecules (CAMs) of the cerebrovascular endothelium regulate infiltration of inflammatory cells into the brain, we have explored the molecular mechanisms by which ortho-substituted polychlorinated biphenyls (PCBs), such as PCB153, can upregulate CAMs in brain endothelial cells. Exposure to PCB153 increased expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), as well as elevated adhesion of leukocytes to brain endothelial cells. These effects were impeded by inhibitors of EGFR, JAKs, or Src activity. In addition, pharmacological inhibition of NADPH oxidase or disruption of lipid rafts by cholesterol depleting agents blocked PCB153-induced phosphorylation of JAK and Src kinases and upregulation of CAMs. In contrast, silencing of caveolin-1 by siRNA interference did not affect upregulation of ICAM-1 and VCAM-1 in brain endothelial cells stimulated by PCB153. Results of the present study indicate that lipid raft-dependent NADPH oxidase/JAK/EGFR signaling mechanisms regulate the expression of CAMs in brain endothelial cells and adhesion of leukocytes to endothelial monolayers. Due to its role in leukocyte infiltration, induction of CAMs may contribute to PCB-induced cerebrovascular disorders and neurotoxic effects in the CNS.

Polychlorinated biphenyls (PCB 101, PCB 153 and PCB 180) alter leptin signaling and lipid metabolism in differentiated 3T3-L1 adipocytes

International Nuclear Information System (INIS)

Ferrante, Maria C.; Amero, Paola; Santoro, Anna; Monnolo, Anna; Simeoli, Raffaele; Di Guida, Francesca; Mattace Raso, Giuseppina; Meli, Rosaria

2014-01-01

Non-dioxin-like polychlorinated biphenyls (NDL-PCBs) are highly lipophilic environmental contaminants that accumulate in lipid-rich tissues, such as adipose tissue. Here, we reported the effects induced by PCBs 101, 153 and 180, three of the six NDL-PCBs defined as indicators, on mature 3T3-L1 adipocytes. We observed an increase in lipid content, in leptin gene expression and a reduction of leptin receptor expression and signaling, when cells were exposed to PCBs, alone or in combination. These modifications were consistent with the occurrence of “leptin-resistance” in adipose tissue, a typical metabolic alteration related to obesity. Therefore, we investigated how PCBs affect the expression of pivotal proteins involved in the signaling of leptin receptor. We evaluated the PCB effect on the intracellular pathway JAK/STAT, determining the phosphorylation of STAT3, a downstream activator of the transcription of leptin gene targets, and the expression of SOCS3 and PTP1B, two important regulators of leptin resistance. In particular, PCBs 153 and 180 or all PCB combinations induced a significant reduction in pSTAT3/STAT3 ratio and an increase in PTP1B and SOCS3, evidencing an additive effect. The impairment of leptin signaling was associated with the reduction of AMPK/ACC pathway activation, leading to the increase in lipid content. These pollutants were also able to increase the transcription of inflammatory cytokines (IL-6 and TNFα). It is worthy to note that the PCB concentrations used are comparable to levels detectable in human adipose tissue. Our data strongly support the hypothesis that NDL-PCBs may interfere with the lipid metabolism contributing to the development of obesity and related diseases. - Highlights: • NDL-PCBs alter lipid content and metabolism in 3T3-L1 adipocytes. • Impairment of leptin signaling was induced by NDL-PCBs. • NDL-PCBs reduce AMPK and ACC activation. • NDL-PCBs induce the synthesis of pro-inflammatory cytokine by

Polychlorinated biphenyls (PCB 101, PCB 153 and PCB 180) alter leptin signaling and lipid metabolism in differentiated 3T3-L1 adipocytes

Energy Technology Data Exchange (ETDEWEB)

Ferrante, Maria C. [Department of Veterinary Medicine and Animal Productions, Federico II University of Naples, Via Delpino 1, 80137 Naples (Italy); Amero, Paola; Santoro, Anna [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Monnolo, Anna [Department of Veterinary Medicine and Animal Productions, Federico II University of Naples, Via Delpino 1, 80137 Naples (Italy); Simeoli, Raffaele; Di Guida, Francesca [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Mattace Raso, Giuseppina, E-mail: mattace@unina.it [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Meli, Rosaria, E-mail: meli@unina.it [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy)

2014-09-15

Non-dioxin-like polychlorinated biphenyls (NDL-PCBs) are highly lipophilic environmental contaminants that accumulate in lipid-rich tissues, such as adipose tissue. Here, we reported the effects induced by PCBs 101, 153 and 180, three of the six NDL-PCBs defined as indicators, on mature 3T3-L1 adipocytes. We observed an increase in lipid content, in leptin gene expression and a reduction of leptin receptor expression and signaling, when cells were exposed to PCBs, alone or in combination. These modifications were consistent with the occurrence of “leptin-resistance” in adipose tissue, a typical metabolic alteration related to obesity. Therefore, we investigated how PCBs affect the expression of pivotal proteins involved in the signaling of leptin receptor. We evaluated the PCB effect on the intracellular pathway JAK/STAT, determining the phosphorylation of STAT3, a downstream activator of the transcription of leptin gene targets, and the expression of SOCS3 and PTP1B, two important regulators of leptin resistance. In particular, PCBs 153 and 180 or all PCB combinations induced a significant reduction in pSTAT3/STAT3 ratio and an increase in PTP1B and SOCS3, evidencing an additive effect. The impairment of leptin signaling was associated with the reduction of AMPK/ACC pathway activation, leading to the increase in lipid content. These pollutants were also able to increase the transcription of inflammatory cytokines (IL-6 and TNFα). It is worthy to note that the PCB concentrations used are comparable to levels detectable in human adipose tissue. Our data strongly support the hypothesis that NDL-PCBs may interfere with the lipid metabolism contributing to the development of obesity and related diseases. - Highlights: • NDL-PCBs alter lipid content and metabolism in 3T3-L1 adipocytes. • Impairment of leptin signaling was induced by NDL-PCBs. • NDL-PCBs reduce AMPK and ACC activation. • NDL-PCBs induce the synthesis of pro-inflammatory cytokine by

Developmental Exposure to an Environmental PCB Mixture ...

Science.gov (United States)

Developmental PCB exposure impairs hearing and induces brainstem audiogenic seizures in adult offspring. The degree to which this enhanced susceptibility to seizure is manifest in other brain regions has not been examined. Thus, electrical kindling of the amygdala was used to evaluate the effect of developmental exposure to an environmentally relevant PCB mixture on seizure susceptibility in the rat. Female Long-Evans rats were dosed orally with 0 or 6 mg/kg/day of the PCB mixture dissolved in corn oil vehicle during the perinatal period. On postnatal day (PND) 21, pups were weaned, and two males from each litter were randomly selected for the kindling study. As adults, the male rats were implanted bilaterally with electrodes in the basolateral amygdala. For each animal, afterdischarge (AD) thresholds in the amygdala were determined on the first day of testing followed by once daily stimulation at a standard 200 µA stimulus intensity until three stage 5 generalized seizures (GS) ensued. Developmental PCB exposure did not affect the AD threshold or total cumulative AD duration, but PCB exposure did increase the latency to behavioral manifestations of seizure propagation. PCB exposed animals required significantly more stimulations to reach stage 2 seizures compared to control animals, indicating an attenuated focal (amygdala) excitability. A delay in kindling progression from a focally stimulated limbic site stands in contrast to our previous finding of increase

Combination effects of AHR agonists and Wnt/β-catenin modulators in zebrafish embryos: Implications for physiological and toxicological AHR functions

Energy Technology Data Exchange (ETDEWEB)

Wincent, Emma [Department of Environmental Toxicology, Uppsala University, 75236 Uppsala (Sweden); Institute of Environmental Medicine, Karolinska Institutet, 17177 Stockholm (Sweden); Stegeman, John J. [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1050 (United States); Jönsson, Maria E., E-mail: maria.jonsson@ebc.uu.se [Department of Environmental Toxicology, Uppsala University, 75236 Uppsala (Sweden)

2015-04-15

Wnt/β-catenin signaling regulates essential biological functions and acts in developmental toxicity of some chemicals. The aryl hydrocarbon receptor (AHR) is well-known to mediate developmental toxicity of persistent dioxin-like compounds (DLCs). Recent studies indicate a crosstalk between β-catenin and the AHR in some tissues. However the nature of this crosstalk in embryos is poorly known. We observed that zebrafish embryos exposed to the β-catenin inhibitor XAV939 display effects phenocopying those of the dioxin-like 3,3′,4,4′,5-pentachlorobiphenyl (PCB126). This led us to investigate the AHR interaction with β-catenin during development and ask whether developmental toxicity of DLCs involves antagonism of β-catenin signaling. We examined phenotypes and transcriptional responses in zebrafish embryos exposed to XAV939 or to a β-catenin activator, 1-azakenpaullone, alone or with AHR agonists, either PCB126 or 6-formylindolo[3,2-b]carbazole (FICZ). Alone 1-azakenpaullone and XAV939 both were embryo-toxic, and we found that in the presence of FICZ, the toxicity of 1-azakenpaullone decreased while the toxicity of XAV939 increased. This rescue of 1-azakenpaullone effects occurred in the time window of Ahr2-mediated toxicity and was reversed by morpholino-oligonucleotide knockdown of Ahr2. Regarding PCB126, addition of either 1-azakenpaullone or XAV939 led to lower mortality than with PCB126 alone but surviving embryos showed severe edemas. 1-Azakenpaullone induced transcription of β-catenin-associated genes, while PCB126 and FICZ blocked this induction. The data indicate a stage-dependent antagonism of β-catenin by Ahr2 in zebrafish embryos. We propose that the AHR has a physiological role in regulating β-catenin during development, and that this is one point of intersection linking toxicological and physiological AHR-governed processes.

Hormetic effects of noncoplanar PCB exposed to human lung fibroblast cells (HELF) and possible role of oxidative stress.

Science.gov (United States)

Hashmi, Muhammad Zaffar; Khan, Kiran Yasmin; Hu, Jinxing; Naveedullah; Su, Xiaomei; Abbas, Ghulam; Yu, Chunna; Shen, Chaofeng

2015-12-01

Hormesis, a biphasic dose-response phenomenon, which is characterized by stimulation of an end point at a low-dose and inhibition at a high-dose. In the present study we used human lungs fibroblast (HELF) cells as a test model to evaluate the role of oxidative stress (OS) in hormetic effects of non coplanar PCB 101. Results from 3-(4,5-dime-thylthiazol-2-yl)-2,5-diphenyltetrazo-lium bromide (MTT) assay indicated that PCB101 at lower concentrations (10(-5) to 10(-1) μg mL(-1) ) stimulated HELF cell proliferation and inhibited at high concentrations (1, 5, 10, and 20 μg mL(-1) ) in a dose- and time-dependent manner. Reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) (except 48 h) showed a significant increase at higher concentrations of PCB 101 than those at the lower concentrations with the passage of time. Antioxidant enzymes such as glutathione peroxidase (GSH-Px) exhibited decreasing trends in dose and time dependent manner. Lipid peroxidation assay resulted in a significant increase (P PCB 101-treated HELF cells compared with controls, suggesting that OS plays a key role in PCB 101-induced toxicity. Comet assay indicated a significant increase in genotoxicity at higher concentrations of PCB 101 exposure compared to lower concentrations. Overall, we found that HELF cell proliferation was higher at low ROS level and vice versa, which revealed activation of cell signaling-mediated hormetic mechanisms. The results suggested that PCB 101 has hormetic effects to HELF cells and these were associated with oxidative stress. © 2014 Wiley Periodicals, Inc.

Polychlorinated biphenyl-induced VCAM-1 expression is attenuated in aortic endothelial cells isolated from caveolin-1 deficient mice

International Nuclear Information System (INIS)

Han, Sung Gu; Eum, Sung Yong; Toborek, Michal; Smart, Eric; Hennig, Bernhard

2010-01-01

Exposure to environmental contaminants, such as polychlorinated biphenyls (PCBs), is a risk factor for the development of cardiovascular diseases such as atherosclerosis. Vascular cell adhesion molecule-1 (VCAM-1) is a critical mediator for adhesion and uptake of monocytes across the endothelium in the early stages of atherosclerosis development. The upregulation of VCAM-1 by PCBs may be dependent on functional membrane domains called caveolae. Caveolae are particularly abundant in endothelial cell membranes and involved in trafficking and signal transduction. The objective of this study was to investigate the role of caveolae in PCB-induced endothelial cell dysfunction. Primary mouse aortic endothelial cells (MAECs) isolated from caveolin-1-deficient mice and background C57BL/6 mice were treated with coplanar PCBs, such as PCB77 and PCB126. In addition, siRNA gene silencing technique was used to knockdown caveolin-1 in porcine vascular endothelial cells. In MAECs with functional caveolae, VCAM-1 protein levels were increased after exposure to both coplanar PCBs, whereas expression levels of VCAM-1 were not significantly altered in cells deficient of caveolin-1. Furthermore, PCB-induced monocyte adhesion was attenuated in caveolin-1-deficient MAECs. Similarly, siRNA silencing of caveolin-1 in porcine endothelial cells confirmed the caveolin-1-dependent VCAM-1 expression. Treatment of cells with PCB77 and PCB126 resulted in phosphorylation of extracellular signal-regulated kinase-1/2 (ERK1/2), and pharmacological inhibition of ERK1/2 diminished the observed PCB-induced increase in monocyte adhesion. These findings suggest that coplanar PCBs induce adhesion molecule expression, such as VCAM-1, in endothelial cells, and that this response is regulated by caveolin-1 and functional caveolae. Our data demonstrate a critical role of functional caveolae in the activation and dysfunction of endothelial cells by coplanar PCBs.

Assessment of the Polychlorinated Biphenyl (PCB Occurrence in Copper Sulfates and the Influential Role of PCB Levels on Grapes.

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Xiaomin Li

Full Text Available Copper sulfates (CuSO4 are widely used as the primary component of fungicides in the grape industry. The agricultural-grade CuSO4 that we collected from Chinese nationwide markets were found to be contaminated by polychlorinated dibenzo-p-dioxins and dibenzofurans and high levels of polychlorinated biphenyls (Σ19PCBs: 0.32~9.51 ng/g. In the following research, we studied the impact of CuSO4 application on PCB levels in grape products through a field experiment, and conducted a national survey to speculate the role that CuSO4 played on the occurrence of PCB in grapes. In the field experiment, an obvious increase of PCBs in grape leaves (from 174 to 250 pg/g fw was observed after Bordeaux mixture (the main component of which is CuSO4 application. As to the main PCB congener in CuSO4, the most toxic CB 126 (toxic equivalency factor = 0.1 also increased in grape peels (from 1.66 to 2.93 pg/g fw after pesticide spray. Both the correlation study and the principal component analysis indicated that environmental factors were dominant PCB contributors to grapes, and grapes from e-waste dismantling area containing the highest PCBs also proved the notion. It is worth noting that this report describes the first research examining PCBs in CuSO4 and its influence on agricultural products to date.

Postnatal exposure to PCB 153 and PCB 180, but not to PCB 52, produces changes in activity level and stimulus control in outbred male Wistar Kyoto rats

Directory of Open Access Journals (Sweden)

Walaas S

2011-05-01

Full Text Available Abstract Background Polychlorinated biphenyls (PCBs are a class of organic compounds that bioaccumulate due to their chemical stability and lipophilic properties. Humans are prenatally exposed via trans-placental transfer, through breast milk as infants, and through fish, seafood and fatty foods as adolescents and adults. Exposure has several reported effects ranging from developmental abnormalities to cognitive and motor deficiencies. In the present study, three experimental groups of rats were orally exposed to PCBs typically found in human breast milk and then behaviorally tested for changes in measures of stimulus control (percentage lever-presses on the reinforcer-producing lever, activity level (responses with IRTs > 0.67 s, and responses with short IRTs ( Methods Male offspring from Wistar Kyoto (WKY/NTac dams purchased pregnant from Taconic Farms (Germantown, NY were orally given PCB at around postnatal day 8, 14, and 20 at a dose of 10 mg/kg body weight at each exposure. Three experimental groups were exposed either to PCB 52, PCB 153, or PCB 180. A fourth group fed corn oil only served as controls. From postnatal day 25, for 33 days, the animals were tested for behavioral changes using an operant procedure. Results PCB exposure did not produce behavioral changes during training when responding was frequently reinforced using a variable interval 3 s schedule. When correct responses were reinforced on a variable interval 180 s schedule, animals exposed to PCB 153 or PCB 180 were less active than controls and animals exposed to PCB 52. Stimulus control was better in animals exposed to PCB 180 than in controls and in the PCB 52 group. Also, the PCB 153 and PCB 180 groups had fewer responses with short IRTs than the PCB 52 group. No effects of exposure to PCB 52 were found when compared to controls. Conclusions Exposure to PCBs 153 and 180 produced hypoactivity that continued at least five weeks after the last exposure. No effects of

Evaluation and interconversion of various indicator PCB schemes for ∑PCB and dioxin-like PCB toxic equivalent levels in fish.

Science.gov (United States)

Gandhi, Nilima; Bhavsar, Satyendra P; Reiner, Eric J; Chen, Tony; Morse, Dave; Arhonditsis, George B; Drouillard, Ken G

2015-01-06

Polychlorinated biphenyls (PCBs) remain chemicals of concern more than three decades after the ban on their production. Technical mixture-based total PCB measurements are unreliable due to weathering and degradation, while detailed full congener specific measurements can be time-consuming and costly for large studies. Measurements using a subset of indicator PCBs (iPCBs) have been considered appropriate; however, inclusion of different PCB congeners in various iPCB schemes makes it challenging to readily compare data. Here, using an extensive data set, we examine the performance of existing iPCB3 (PCB 138, 153, and 180), iPCB6 (iPCB3 plus 28, 52, and 101) and iPCB7 (iPCB6 plus 118) schemes, and new iPCB schemes in estimating total of PCB congeners (∑PCB) and dioxin-like PCB toxic equivalent (dlPCB-TEQ) concentrations in sport fish fillets and the whole body of juvenile fish. The coefficients of determination (R(2)) for regressions conducted using logarithmically transformed data suggest that inclusion of an increased number of PCBs in an iPCB improves relationship with ∑PCB but not dlPCB-TEQs. Overall, novel iPCB3 (PCB 95, 118, and 153), iPCB4 (iPCB3 plus 138) and iPCB5 (iPCB4 plus 110) presented in this study and existing iPCB6 and iPCB7 are the most optimal indicators, while the current iPCB3 should be avoided. Measurement of ∑PCB based on a more detailed analysis (50+ congeners) is also overall a good approach for assessing PCB contamination and to track PCB origin in fish. Relationships among the existing and new iPCB schemes have been presented to facilitate their interconversion. The iPCB6 equiv levels for the 6.5 and 10 pg/g benchmarks of dlPCB-TEQ05 are about 50 and 120 ng/g ww, respectively, which are lower than the corresponding iPCB6 limits of 125 and 300 ng/g ww set by the European Union.

Microbial decomposition of PCB. PCB no biseibutsu bunkai

Energy Technology Data Exchange (ETDEWEB)

Furukawa, K [Kyushu University, Fukuoka (Japan). Faculty of Agriculture

1993-08-01

This paper generalizes knowledges acquired so far on bio-remediation of PCB. Aerobic PCB decomposition using soil bacteria generally goes through introduction of O2 into second and third orders of a biphenyl ring, ring cleavage, and hydrolysis, and generates benzoate finally. PCB that is decomposed in this 2, 3-dioxygenaze path requires at least one of the second and third orders to be open. The decomposition through this path becomes difficult when the number of displaced Cl increases, and PCB with Cl displaced in only one of the rings decomposes more easily than PCB with the same number of Cl in both rings. A group in GE, Inc. has searched for two kinds of bacteria stocks that introduce O2 preferentially into the third and fourth orders. These stocks decompose third and fourth ordered open high-chlorine PCB. Groups in GE, Inc. and other companies have isolated bacteria that dechlorinate PCB decreasingly under an anaerobic condition. These bacteria desorb metha-ordered chlorine. Discussions are being made on cloning of PCB decomposing genes, and breeding of decomposing bacteria that have wide PCB decomposing spectra. 22 refs., 8 figs., 2 tabs.

Effects of maternal exposure to estrogen and PCB on different life stages of Zebrafish (Danio rerio)

Energy Technology Data Exchange (ETDEWEB)

Olsson, Per-Erik; Westerlund, L; Billsson, K; Berg, A H [Umeaa Univ. (Sweden). Dept. of Cellular and Developmental Biology; Teh, S J; Hinton, D E [California Univ., Davis, CA (United States). Dept. of Anatomy, Physiology and Cell Biology; Tysklind, M [Umeaa Univ., (Sweden). Dept. of Environmental Chemistry; Nilsson, Jan; Eriksson, Lars-Ove [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Aquaculture

1999-02-01

PCBs have been found to impair both reproduction and development in fish. We have investigated the effects of 3 PCB congeners, 2,3,3`,4,4`,5,6-HpCB (PCB-190); 2,3,4,4`-TeCB (PCB-60); and 2,2`,4,6,6`-PeCB (PCB-104), and the estrogenic hormone 17{beta}-estradiol on fecundity, early life-stage mortality, gross morphology and histology of zebrafish (Danio rerio). While none of the studied substances reduced fecundity, they increased embryo and larval mortality. The most severe effects on viability were observed following treatment with 17{beta}-estradiol or the weakly estrogenic PCB-104. Following 17{beta}-estradiol or PCB-104 exposure, mortality continued through the yolksac absorption phase. PCB-60, on the other hand, resulted in mortality between the 30% epiboly stage and 75% epiboly stage. At the same time as embryos started to die, embryo development and hatching were delayed. PCB-190 showed only moderate effects on early-life stage mortality. The fish were reared until sexual maturation where after they were subjected to gross morphological and histological analyses. Changes in morphology were observed following PCB-104 and PCB-190 treatment. Both substances gave rise to craniofacial malformations while PCB-104 also led to lordosis in females and scoliosis in fish of both sexes. From histological analysis it was found that PCB-104 and 17{beta}-estradiol resulted in karyorrhexis and karyolysis in the kidney. Possible signs of bile stasis were observed following 17{beta}-estradiol and PCB-190 treatment. Some effects were observed on the gonads, including areas in the ovary showing atresia and limited failure of testicular spermatogenesis in 17{beta}-estradiol, PCB-104, and PCB-60 treated fish. While all studied substances resulted in effects on offspring, the observation that estrogenic substances are highly embryotoxic, raises concern that endocrine disrupting substances may severely reduce fish populations in polluted areas

In vitro profiling of toxic effects of prominent environmental lower-chlorinated PCB congeners linked with endocrine disruption and tumor promotion.

Science.gov (United States)

Pěnčíková, Kateřina; Svržková, Lucie; Strapáčová, Simona; Neča, Jiří; Bartoňková, Iveta; Dvořák, Zdeněk; Hýžďalová, Martina; Pivnička, Jakub; Pálková, Lenka; Lehmler, Hans-Joachim; Li, Xueshu; Vondráček, Jan; Machala, Miroslav

2018-06-01

The mechanisms contributing to toxic effects of airborne lower-chlorinated PCB congeners (LC-PCBs) remain poorly characterized. We evaluated in vitro toxicities of environmental LC-PCBs found in both indoor and outdoor air (PCB 4, 8, 11, 18, 28 and 31), and selected hydroxylated metabolites of PCB 8, 11 and 18, using reporter gene assays, as well as other functional cellular bioassays. We focused on processes linked with endocrine disruption, tumor promotion and/or regulation of transcription factors controlling metabolism of both endogenous compounds and xenobiotics. The tested LC-PCBs were found to be mostly efficient anti-androgenic (within nanomolar - micromolar range) and estrogenic (at micromolar concentrations) compounds, as well as inhibitors of gap junctional intercellular communication (GJIC) at micromolar concentrations. PCB 8, 28 and 31 were found to partially inhibit the aryl hydrocarbon receptor (AhR)-mediated activity. The tested LC-PCBs were also partial constitutive androstane receptor (CAR) and pregnane X receptor (PXR) agonists, with PCB 4, 8 and 18 being the most active compounds. They were inactive towards other nuclear receptors, such as vitamin D receptor, thyroid receptor α, glucocorticoid receptor or peroxisome proliferator-activated receptor γ. We found that only PCB 8 contributed to generation of oxidative stress, while all tested LC-PCBs induced arachidonic acid release (albeit without further modulations of arachidonic acid metabolism) in human lung epithelial cells. Importantly, estrogenic effects of hydroxylated (OH-PCB) metabolites of LC-PCBs (4-OH-PCB 8, 4-OH-PCB 11 and 4'-OH-PCB 18) were higher than those of the parent PCBs, while their other toxic effects were only slightly altered or suppressed. This suggested that metabolism may alter toxicity profiles of LC-PCBs in a receptor-specific manner. In summary, anti-androgenic and estrogenic activities, acute inhibition of GJIC and suppression of the AhR-mediated activity were

Up-regulation of endothelial monocyte chemoattractant protein-1 by coplanar PCB77 is caveolin-1-dependent

International Nuclear Information System (INIS)

Majkova, Zuzana; Smart, Eric; Toborek, Michal; Hennig, Bernhard

2009-01-01

Atherosclerosis, the primary cause of heart disease and stroke is initiated in the vascular endothelium, and risk factors for its development include environmental exposure to persistent organic pollutants. Caveolae are membrane microdomains involved in regulation of many signaling pathways, and in particular in endothelial cells. We tested the hypothesis that intact caveolae are required for coplanar PCB77-induced up-regulation of monocyte chemoattractant protein-1 (MCP-1), an endothelium-derived chemokine that attracts monocytes into sub-endothelial space in early stages of the atherosclerosis development. Atherosclerosis-prone LDL-R -/- mice (control) or caveolin-1 -/- /LDL-R -/- mice were treated with PCB77. PCB77 induced aortic mRNA expression and plasma protein levels of MCP-1 in control, but not caveolin-1 -/- /LDL-R -/- mice. To study the mechanism of this effect, primary endothelial cells were used. PCB77 increased MCP-1 levels in endothelial cells in a time- and concentration-dependent manner. This effect was abolished by caveolin-1 silencing using siRNA. Also, MCP-1 up-regulation by PCB77 was prevented by inhibiting p38 and c-Jun N-terminal kinase (JNK), but not ERK1/2, suggesting regulatory functions via p38 and JNK MAPK pathways. Finally, pre-treatment of endothelial cells with the aryl hydrocarbon receptor (AhR) inhibitor α-naphthoflavone (α-NF) partially blocked MCP-1 up-regulation. Thus, our data demonstrate that coplanar PCB77 can induce MCP-1 expression by endothelial cells and that this effect is mediated by AhR, as well as p 38 and JNK MAPK pathways. Intact caveolae are required for these processes both in vivo and in vitro. This further supports a key role for caveolae in vascular inflammation induced by persistent organic pollutants.

PCB-induced changes of a benthic community and expected ecosystem recovery following in situ sorbent amendment

Science.gov (United States)

Janssen, Elisabeth M.-L.; Thompson, Janet K.; Luoma, Samuel N.; Luthy, Richard G.

2011-01-01

The benthic community was analyzed to evaluate pollution-induced changes for the polychlorinated biphenyl (PCB)-contaminated site at Hunters Point (HP) relative to 30 reference sites in San Francisco Bay, California, USA. An analysis based on functional traits of feeding, reproduction, and position in the sediment shows that HP is depauperate in deposit feeders, subsurface carnivores, and species with no protective barrier. Sediment chemistry analysis shows that PCBs are the major risk drivers at HP (1,570 ppb) and that the reference sites contain very low levels of PCB contamination (9 ppb). Different feeding traits support the existence of direct pathways of exposure, which can be mechanistically linked to PCB bioaccumulation by biodynamic modeling. The model shows that the deposit feeder Neanthes arenaceodentata accumulates approximately 20 times more PCBs in its lipids than the facultative deposit feeder Macoma balthica and up to 130 times more than the filter feeder Mytilus edulis. The comparison of different exposure scenarios suggests that PCB tissue concentrations at HP are two orders of magnitude higher than at the reference sites. At full scale, in situ sorbent amendment with activated carbon may reduce PCB bioaccumulation at HP by up to 85 to 90% under favorable field and treatment conditions. The modeling framework further demonstrates that such expected remedial success corresponds to exposure conditions suggested as the cleanup goal for HP. However, concentrations remain slightly higher than at the reference sites. The present study demonstrates how the remedial success of a sorbent amendment, which lowers the PCB availability, can be compared to reference conditions and traditional cleanup goals, which are commonly based on bulk sediment concentrations.

Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type

DEFF Research Database (Denmark)

Gomes, Helena I.; Dias-Ferreira, Celia; Ottosen, Lisbeth M.

2015-01-01

Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero...... nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used...... as windows sealants. Saponin, a natural surfactant, was also tested to increase the PCB desorption from soils and enhance dechlorination. Remediation of Soil 1 (with highest pH, carbonate content, organic matter and PCB concentrations) obtained the maximum 83% and 60% PCB removal with the two...

PCB-153 shows different dynamics of mobilisation from differentiated rat adipocytes during lipolysis in comparison with PCB-28 and PCB-118.

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Louis, Caroline; Tinant, Gilles; Mignolet, Eric; Thomé, Jean-Pierre; Debier, Cathy

2014-01-01

Polychlorinated biphenyls (PCBs) are persistent organic pollutants. Due to their lipophilic character, they are preferentially stored within the adipose tissue. During the mobilisation of lipids, PCBs might be released from adipocytes into the bloodstream. However, the mechanisms associated with the release of PCBs have been poorly studied. Several in vivo studies followed their dynamics of release but the complexity of the in vivo situation, which is characterised by a large range of pollutants, does not allow understanding precisely the behaviour of individual congeners. The present in vitro experiment studied the impact of (i) the number and position of chlorine atoms of PCBs on their release from adipocytes and (ii) the presence of other PCB congeners on the mobilisation rate of such molecules. Differentiated rat adipocytes were used to compare the behaviour of PCB-28, -118 and -153. Cells were contaminated with the three congeners, alone or in cocktail, and a lipolysis was then induced with isoproterenol during 12 hours. Our data indicate that the three congeners were efficiently released from adipocytes and accumulated in the medium during the lipolysis. Interestingly, for a same level of cell lipids, PCB-153, a hexa-CB with two chlorine atoms in ortho-position, was mobilised slower than PCB-28, a tri-CB, and PCB-118, a penta-CB, which are both characterised by one chlorine atom in ortho-position. It suggests an impact of the chemical properties of pollutants on their mobilisation during periods of negative energy balance. Moreover, the mobilisation of PCB congeners, taken individually, did not seem to be influenced by the presence of other congeners within adipocytes. These results not only highlight the obvious mobilisation of PCBs from adipocytes during lipolysis, in parallel to lipids, but also demonstrate that the structure of congeners defines their rate of release from adipocytes.

Effects of PCB contamination on the reproduction of the DAB Limanda limanda L. under laboratory conditions

Science.gov (United States)

Fonds, Mark; Casal, Elizabeth; Schweizer, Dominik; Boon, Jan P.; Van der Veer, Henk W.

The effect of PCB contamination on the reproduction of female dab was studied under laboratory conditions. Females were contaminated during gonad maturation by multiple oral administration of capsules containing the technical PCB mixture Clophen A40. PCB contamination resulted in increased levels in the eggs, with concentrations of selected PCB congeners of 35 to 86 μg·g -1 lipid for PCB-exposed fish, 10 μg·g -1 lipid for eggs from fish fed with mussel meat and fish fed with shrimp. A statistically significant dose-effect relationship was found between the PCB content of the eggs and the PCB dose ingested by the fish. For eggs from the PCB-treated fish the mean fertilization rate was 61% and mean hatching 45%, compared to 67% fertilization and 59% hatching for eggs from untreated fish. Rate of development and survival of the eggs and mortality of the larvae after hatching were mainly related to incubation temperature. No statistically significant differences between untreated and PCB-treated fish could be found in egg production, egg quality, fertilization rate, hatching rate and survival of larvae.

Polychlorinated biphenyl (PCB) concentrations and congener composition in masu salmon from Japan: A study of all 209 PCB congeners by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS)

International Nuclear Information System (INIS)

Matsumoto, Reiko; Tu, Nguyen Phuc Cam; Haruta, Shinsuke; Kawano, Masahide; Takeuchi, Ichiro

2014-01-01

Highlights: • Two subspecies of masu salmon collected from central to northern Japan were examined. • All 209 PCB congeners in the fish were analyzed by HRGC/HRMS with δ 15 N and δ 13 C determinations. • ∑ PCBs was highest in fish that had upstreamed from Ise Bay, which is close to a heavy industrial area. • However, TEQ dl-PCBs values were highest in fish from southern part of the Sea of Japan. - Abstract: We collected two subspecies of masu salmon: Oncorhynchus masou masou from four localities (southern Sea of Japan northward to Hokkaido) and O. masou ishikawae from upstream from Ise Bay close to a heavy industrial area. All 209 PCB congeners were analyzed using HRGC/HRMS. PCA ordination of congener concentrations divided data into three groups: (i) ssp. masou from Hokkaido, (ii) ssp. masou from the other regions and (iii) ssp. ishikawae. The highest ∑ PCB concentration (40.39 ng/wet wt) was in ssp. ishikawae followed by ssp. masou from southern waters; however the TEQ dioxin-like PCBs was highest in ssp. masou from southern water (1.96 pg-TEQ dioxin-like PCBs /g wet wt.) due to the high proportion of congener #126 in its complement (#126 has the highest toxic equivalency factor among congeners). There is likely a contamination source offshore in the southern Sea of Japan and/or along the migratory route of ssp. masou

Dioxins, DL-PCB and NDL-PCB accumulation profiles in livers from sheep and cattle reared in North-western Italy.

Science.gov (United States)

Benedetto, A; Brizio, P; Guaraldo, P; Stella, C; Cappa, C; Baioni, E; Spalenza, V; Nebbia, C; Abete, M C

2016-06-01

Products of animal origin represent the main route of human exposure to dioxins and dioxin-like PCBs (DL-compounds). Recently, concerns have been raised about ovine products, particularly the liver, in which relatively high levels of DL-compounds have been reported. We surveyed ovine and bovine livers in areas with no known sources of dioxin or DL-PCB contamination, in order to assess accumulation patterns for both DL-compounds and non-DL (NDL-) PCBs. None of the ovine and bovine samples exceeded the current Maximum Limits (MLs) for DL-compounds. Liver DL-compound TEQ concentrations were up to 5-fold higher in sheep than in cows. No statistically significant differences in total NDL-PCBs levels were found. The main contributors to TEQ levels were the Penta- and Hexa-chlorinated PCDFs and PCB 126. The results confirm the increased bioaccumulation in ovine liver towards specific DL-compounds even in ewes reared in areas with no known sources of PCDD/Fs or DL-PCBs contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mixture effects of 30 environmental contaminants on incident metabolic syndrome-A prospective study.

Science.gov (United States)

Lind, Lars; Salihovic, Samira; Lampa, Erik; Lind, P Monica

2017-10-01

Several cross-sectional studies have linked different environmental contaminants to the metabolic syndrome (MetS). However, mixture effects have not been investigated and no prospective studies exist regarding environmental contaminants and the MetS. To study mixture effects of contaminants on the risk of incident MetS in a prospective fashion. Our sample consisted of 452 subjects from the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study (50% women, all aged 70years) free from the MetS at baseline, being followed for 10years. At baseline, 30 different environmental contaminants were measured; 6 polychlorinated biphenyls (PCBs), 3 organochlorine (OC) pesticides, one dioxin, one polybrominated diphenyl ether (all in plasma), 8 perfluoroalkyl substances (in plasma) and 11 metals (in whole blood). The MetS was defined by the ATPIII/NCEP criteria. Gradient boosted Classification and Regression Trees (CARTs) was used to evaluate potential synergistic and additive mixture effects on incident MetS. During 10-year follow-up, 92 incident cases of the MetS occurred. PCB126, PCB170, hexachlorobenzene (HCB) and PCB118 levels were all associated with incident MetS in an additive fashion (OR 1.73 for a change from 10th to 90th percentile (95%CI 1.24-3.04) for PCB126, OR 0.63 (0.42-0.78) for PCB170, OR 1.44 (1.09-2.20) for HCB and OR 1.46 (1.13-2.43) for PCB118). No synergistic effects were found. A mixture of environmental contaminants, with PCB126, PCB170, HCB and PCB118 being the most important, showed associations with future development of the MetS in an additive fashion in this prospective study. Thus, mixture effects of environmental contaminants could contribute to the development of cardio-metabolic derangements. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Monitoring serum PCB levels in the adult population of the Canary Islands (Spain

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Guillermo Burillo-Putze

2015-07-01

Full Text Available Polychlorinated biphenyls (PCBs are persistent organic chemicals that have been detected in human serum or tissues all over the world. These pollutants could exert a number of deleterious effects on humans and wildlife, including carcinogenic processes. The Spanish population of the Canary Islands was evaluated with respect to PCB levels more than ten years ago showing lower levels than other Western populations. The objective of our study was to assess the current level of contamination by PCBs showed by this population. We measured serum PCBs in a sample of healthy adult subjects (206 serum samples from subjects with an average age of 66 years old to evaluate the potential modification of PCB serum levels in this population during the last decade. PCB congeners (28, 52, 77, 81, 101, 105, 114, 118, 123, 126, 138, 153, 156, 157, 167, 169, 180, and 189 were measured by gas chromatography-mass spectrometry (GC/MS. Our results showed that PCB residues were found in 84% of serum samples analyzed, the congeners 28, 153 and 180 being the most frequently detected and at the highest median values (0.1 ng/mL. In addition, the median concentration of the sum of those PCBs considered as markers of environmental contamination by these chemicals (Marker-PCBs was 0.6 ng/mL, reaching values as high as as 2.6 ng/mL in the 95th percentile. Levels of the sum of PCBs with toxic effects similar to dioxins (dioxin-like PCBs reached median values of 0.4 ng/mL in the 95th percentile. The reported levels are similar to those described previously in this population more than ten years ago, in the sense that the inhabitants of the Canary Archipelago show levels of PCB contamination lower than the majority of populations from developed countries. These findings suggest that currently there is not any active source of these chemicals in this archipelago. Nevertheless, as foods seem to be a relevant source for these compounds, Public Health authorities should monitor the

Dechlorination of PCB by radiation

International Nuclear Information System (INIS)

Shinozaki, Yoshiharu

1978-01-01

On the PCB poisoning accident in Japan occurred in 1968, Tokyo Metropolitan Isotope Research Center started to investigate the decomposition of PCB (polychlorinated biphenyl) on the request of Metropolitan government. The research center has found that if PCB is dissolved or extracted in alkaline 2-propanol solution and then irradiated with γ-ray, PCB is dechlorinated in chain-reactive manner, and biphenyl and salts (KCl or NaCl) are formed. Afterwards, it has been found that photolysis has also similar effect on PCB. Then, the basic design of a disposal pilot plant using ultraviolet ray and its economic evaluation have been performed, which is composed of photolysis reaction process, refining process and waste disposal process. However, its disposal cost only has reached the value three times as high as that of incineration process. If this is conducted by radiolysis, its disposal cost can be reduced to about 1/12 of that of ultraviolet ray system when an electron accelerator is employed. Cs-137 source gives better results than Co-60. Dechlorination process of PCB has been thus established. Further reduction of total cost will be the keypoint of radiolysis system to be adopted. If the application of electron accelerators to sludge treatment in the future, the effective use of recovered products, and the possibility of using Cs-137 large sources are considered, it is expected that the disposal cost of radiolysis process system becomes comparable with the incineration process. (Wakatsuki, Y.)

Physical exercise reduces pyruvate carboxylase (PCB) and contributes to hyperglycemia reduction in obese mice.

Science.gov (United States)

Muñoz, Vitor Rosetto; Gaspar, Rafael Calais; Crisol, Barbara Moreira; Formigari, Guilherme Pedron; Sant'Ana, Marcella Ramos; Botezelli, José Diego; Gaspar, Rodrigo Stellzer; da Silva, Adelino S R; Cintra, Dennys Esper; de Moura, Leandro Pereira; Ropelle, Eduardo Rochete; Pauli, José Rodrigo

2018-07-01

The present study evaluated the effects of exercise training on pyruvate carboxylase protein (PCB) levels in hepatic tissue and glucose homeostasis control in obese mice. Swiss mice were distributed into three groups: control mice (CTL), fed a standard rodent chow; diet-induced obesity (DIO), fed an obesity-inducing diet; and a third group, which also received an obesity-inducing diet, but was subjected to an exercise training protocol (DIO + EXE). Protocol training was carried out for 1 h/d, 5 d/wk, for 8 weeks, performed at an intensity of 60% of exhaustion velocity. An insulin tolerance test (ITT) was performed in the last experimental week. Twenty-four hours after the last physical exercise session, the animals were euthanized and the liver was harvested for molecular analysis. Firstly, DIO mice showed increased epididymal fat and serum glucose and these results were accompanied by increased PCB and decreased p-Akt in hepatic tissue. On the other hand, physical exercise was able to increase the performance of the mice and attenuate PCB levels and hyperglycemia in DIO + EXE mice. The above findings show that physical exercise seems to be able to regulate hyperglycemia in obese mice, suggesting the participation of PCB, which was enhanced in the obese condition and attenuated after a treadmill running protocol. This is the first study to be aimed at the role of exercise training in hepatic PCB levels, which may be a novel mechanism that can collaborate to reduce the development of hyperglycemia and type 2 diabetes in DIO mice.

PCB concentrations of lake whitefish (Coregonus clupeaformis) vary by sex

Science.gov (United States)

Madenjian, Charles P.; Ebener, Mark P.; Sepulveda, Maria S.

2015-01-01

We determined whole-fish polychlorinated biphenyl (PCB) concentrations in 26 female lake whitefish (Coregonus clupeaformis) and 34 male lake whitefish from northern Lake Huron. In 5 of the 26 female lake whitefish, we also determined PCB concentrations in the somatic tissue and ovaries. In addition, bioenergetics modeling was used to determine the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 60 ng/g and 80 ng/g, respectively; thus males were 34% higher in PCB concentration compared with females. Based on the PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 2.5%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain, to any degree, the higher PCB concentrations observed in males compared with females. Bioenergetics modeling results indicated that the growth dilution effect could account for males being only 0.7% higher in PCB concentration compared with females. Thus, the growth dilution effect contributed very little to the observed difference in PCB concentrations between the sexes. We conclude that males were higher than females in PCB concentration most likely due to a higher rate of energy expenditure, stemming from greater activity and a greater resting metabolic rate. A higher rate of energy expenditure leads to a higher rate of food consumption, which, in turn, leads to a higher PCB accumulation rate.

Comparative developmental toxicity of planar polychlorinated biphenyl congeners in chickens, American kestrels, and common terns

Science.gov (United States)

Hoffman, D.J.; Melancon, M.J.; Klein, P.N.; Eisemann, J.D.; Spann, J.W.

1998-01-01

The effects of PCB congeners, PCB 126 (3,3',4,4',5-pentaCB) and PCB 77 (3,3'4,4'-tetraCB), were examined in chicken (Gallus gallus), American kestrel (Falco sparverius), and common tern (Sterna hirundo) embryos through hatching, following air cell injections on day 4. PCB 126 caused malformations and edema in chickens starting at 0.3 ppb, in kestrels at 2.3 ppb, but in terns only at levels affecting hatching success (44 ppb). Extent of edema was most severe in chickens and least in terns. Defects of the beak were common in all species, but with crossed beak most prevalent in terns. Effects on embryo growth were most apparent for PCB 126 in chickens and kestrels. The approximate LD50 for PCB 126 in chickens was 0.4 ppb, in kestrels was 65 ppb, and in terns was 104 ppb. The approximate LD50 for PCB 77 in chickens was 2.6 ppb and in kestrels was 316 ppb. Induction of cytochrome P450 associated monooxygenase activity (EROD activity) by PCB 126 in chick embryo liver was about 800 times more responsive than in tern and at least 1000 times more responsive than in kestrel. High concentrations of PCB 126 found in bald eagle eggs are nearly 20-fold higher than the lowest toxic concentration tested in kestrels. Concentrations of PCB 126 causing low level toxic effects in common tern eggs are comparable to highest levels in common terns and Forster's terns in the field, suggesting additional involvement of other compounds in the Great Lakes.

Serum PCB levels and congener profiles among teachers in PCB-containing schools: a pilot study

Science.gov (United States)

2011-01-01

Background PCB contamination in the built environment may result from the release of PCBs from building materials. The significance of this contamination as a pathway of human exposure is not well-characterized, however. This research compared the serum PCB concentrations, and congener profiles between 18 teachers in PCB-containing schools and referent populations. Methods Blood samples from 18 teachers in PCB-containing schools were analyzed for 57 PCB congeners. Serum PCB concentrations and congener patterns were compared between the teachers, to the 2003-4 NHANES (National Health and Nutrition Examination Survey) data, and to data from 358 Greater Boston area men. Results Teachers at one school had higher levels of lighter (PCB 6-74) congeners compared to teachers from other schools. PCB congener 47 contributed substantially to these elevated levels. Older teachers (ages 50-64) from all schools had higher total (sum of 33 congeners) serum PCB concentrations than age-comparable NHANES reference values. Comparing the teachers to the referent population of men from the Greater Boston area (all under age 51), no difference in total serum PCB levels was observed between the referents and teachers up to 50 years age. However, the teachers had significantly elevated serum concentrations of lighter congeners (PCB 6-74). This difference was confirmed by comparing the congener-specific ratios between groups, and principal component analysis showed that the relative contribution of lighter congeners differed between the teachers and the referents. Conclusions These findings suggest that the teachers in the PCB-containing buildings had higher serum levels of lighter PCB congeners (PCB 6-74) than the referent populations. Examination of the patterns, as well as concentrations of individual PCB congeners in serum is essential to investigating the contributions from potential environmental sources of PCB exposure. PMID:21668970

Thermal dechlorination of PCB-209 over Ca species-doped Fe₂O₃.

Science.gov (United States)

Su, Guijin; Huang, Linyan; Shi, Ruifang; Liu, Yexuan; Lu, Huijie; Zhao, Yuyang; Yang, Fan; Gao, Lirong; Zheng, Minghui

2016-02-01

Degradation reaction of decachlorobiphenyl (PCB-209) was investigated over the synthesized Ca species-doped Fe2O3 at 300 °C. The 1%Ca-Fe2O3 exhibited the highest activity among the four catalysts prepared with the pseudo-first order reaction at k(obs) = 0.103 min(-1). PCB-207, PCB-197, PCB-176, PCB-184, PCB-150, PCB-136, PCB-148, PCB-104, PCB-96, PCB-54, PCB-19, PCB-4 and PCB-1 were identified as the dominant isomers in their respective nonachlorobiphenyl (NonaCB) to monochlorobiphenyl (MonoCB) homologue groups. Analysis of the hydrodechlorination products indicated that dechlorination was much more favored on meta- and para-than on ortho-positions. The formation of significantly predominant NonaCB and octachlorobiphenyl (OctaCB) isomers was attributed to lower energy principles and to the 90° dihedral angles of two aromatic rings which prevented the hydrodechlorination at ortho-positions. When the number of chlorine atoms is not more than 7, the steric effect supports the formation of predominant PCB isomers having chlorines at four ortho-positions. During the dechlorination of tetrachlorobiphenyl (TetraCB) formed to generate monochlorobiphenyl (MonoCB) isomers, the chlorine atoms fully substituted at the ortho-positions have to be successively removed, with the first two dechlorinations preferentially occurring at the two different benzene rings. This is dissimilar to that of octachloronaphthalene (PCN-75) in which the hydrodechlorination reaction happened preferentially at ortho-position due to the existence of steric effects. The opposite roles of the steric effect in ortho-position between PCB-209 and PCN-75 might be due to the difference of the π-conjugated plane caused by the dihedral angle of 90° and 0° of the two aromatic rings. Copyright © 2015 Elsevier Ltd. All rights reserved.

Interactive effects of hypoxia and PCB co-exposure on expression of CYP1A and its potential regulators in Atlantic croaker liver.

Science.gov (United States)

Rahman, Md Saydur; Thomas, Peter

2018-04-01

Although marine and coastal environments which are contaminated with xenobiotic organic compounds often become hypoxic during the summer, the interactive effects of hypoxia and xenobiotic exposure on marine species such as teleost fishes remain poorly understood. The expression and activity of monooxygenase enzyme cytochrome P450-1A (CYP1A) in fishes are upregulated by exposure to polychlorinated biphenyls (PCBs), whereas they are down-regulated during hypoxia exposure. We investigated the interactive effects of hypoxia and PCB co-exposure on hepatic CYP1A expression in Atlantic croaker and on potential regulators of CYP1A. Croaker were exposed to hypoxia (1.7 mg/L dissolved oxygen), 3,3',4,4'-tetrachlorobiphenyl (PCB 77, dose: 2 and 8 µg/g body weight), and Aroclor 1254 (a common PCB mixture, dose: 0.5 and 1 µg/g body weight), alone and in combination for 4 weeks. PCB 77 exposure markedly increased hepatic CYP1A mRNA and protein expression, and ethoxyresorufin-O-deethylase (EROD, an indicator of CYP1A enzyme) activity and increased endothelial nitric oxide synthase (eNOS) protein expression. PCB 77 treatment also increased interleukin-1β (IL-1β, a cytokine) mRNA levels and protein carbonyl (PC, an indicator of reactive oxygen species, ROS) contents. These marked PCB 77- and Aroclor 1254-induced increases in CYP1A mRNA levels and EROD activity were significantly attenuated by co-exposure to hypoxia, whereas the increases in hepatic eNOS protein and IL-1β mRNA expression, and PC contents were augmented by hypoxia co-exposure. The results suggest that biotransformation of organic xenobiotics by CYP1A is reduced in fish during co-exposure to hypoxia and is accompanied by alterations in eNOS, ROS, and IL-1β levels. © 2018 Wiley Periodicals, Inc.

PCB138, but not PCB153 and PCB180, acts as a weak antiandrogen in vitro

DEFF Research Database (Denmark)

Vinggaard, A.M.; Bonefeld-Jørgensen, Eva Cecilie

2000-01-01

The polychlorinated biphenyls (PCBs) constitute a group of persistent environmental chemicals including 209 possible congeners exhibiting a variety of chlorine substitution patterns. Due to their lipophilic nature and resistance toward biotransformation, PCBs accumulate in the food chain and all...... environmental matrixes including human adipose tissue, blood and milk. In most biological extracts PCB#138 (2,2',3,4,4',5-hexaCB), PCB#153 (2,2',4,4',5,5'-hexaCB), and PCB#180 (2,2',3,4,4',5,5'-heptaCB) are the dominating components. Depending on the position and number of chlorine substitutions, different...... classes of PCB congeners elicit a complex spectrum of biological and toxic responses in in vivo and in vitro models. Some PCBs exert dioxin-like activities mediated through the aryl hydrocarbon receptor (Ah receptor) giving rise to health risk such as organ toxicity and carcinogenesis. Although reports...

Effects of natural organic matter on PCB-activated carbon sorption kinetics: implications for sediment capping applications.

Science.gov (United States)

Fairey, Julian L; Wahman, David G; Lowry, Gregory V

2010-01-01

In situ capping of polychlorinated biphenyl (PCB)-contaminated sediments with a layer of activated carbon has been proposed, but several questions remain regarding the long-term effectiveness of this remediation strategy. Here, we assess the degree to which kinetic limitations, size exclusion effects, and electrostatic repulsions impaired PCB sorption to activated carbon. Sorption of 11 PCB congeners with activated carbon was studied in fixed bed reactors with organic-free water (OFW) and Suwannee River natural organic matter (SR-NOM), made by reconstituting freeze-dried SR-NOM at a concentration of 10 mg L(-1) as carbon. In the OFW test, no PCBs were detected in the column effluent over the 390-d study, indicating that PCB-activated carbon equilibrium sorption capacities may be achieved before breakthrough even at the relatively high hydraulic loading rate (HLR) of 3.1 m h(-1). However, in the SR-NOM fixed-bed test, partial PCB breakthrough occurred over the entire 320-d test (HLRs of 3.1-, 1.5-, and 0.8 m h(-1)). Simulations from a modified pore and surface diffusion model indicated that external (film diffusion) mass transfer was the dominant rate-limiting step but that internal (pore diffusion) mass transfer limitations were also present. The external mass transfer limitation was likely caused by formation of PCB-NOM complexes that reduced PCB sorption through a combination of (i) increased film diffusion resistance; (ii) size exclusion effects; and (iii) electrostatic repulsive forces between the PCBs and the NOM-coated activated carbon. However, the seepage velocities in the SR-NOM fixed bed test were about 1000 times higher than would be expected in a sediment cap. Therefore, additional studies are needed to assess whether the mass transfer limitations described here would be likely to manifest themselves at the lower seepage velocities observed in practice.

The Engineering Of PCB Processing Machine

International Nuclear Information System (INIS)

Handoyo, Demon; Satmoko, Ari; T, Sapta; Heru, G. B.

2001-01-01

The engineering of PCB processing machine had been done. Purposes of the engineering of PCB processing machine are used to process PCB and to get the data's of characteristic of PCB processing. Further, these data's will be used as setting point when processing of PCB is done with manual and automatic control. The method of processing of PCB are inserting and pulling of the PCB rack to and from Ferro chlorite using electrical motor to corrosive Cu shield parts witch is not used. The experiment have result that the characteristic of operation of PCB processing machine as we hope when designing

Electroremediation of PCB contaminated soil combined with iron nanoparticles: Effect of the soil type.

Science.gov (United States)

Gomes, Helena I; Dias-Ferreira, Celia; Ottosen, Lisbeth M; Ribeiro, Alexandra B

2015-07-01

Polychlorinated biphenyls (PCB) are carcinogenic and persistent organic pollutants that accumulate in soils and sediments. Currently, there is no cost-effective and sustainable remediation technology for these contaminants. In this work, a new combination of electrodialytic remediation and zero valent iron particles in a two-compartment cell is tested and compared to a more conventional combination of electrokinetic remediation and nZVI in a three-compartment cell. In the new two-compartment cell, the soil is suspended and stirred simultaneously with the addition of zero valent iron nanoparticles. Remediation experiments are made with two different historically PCB contaminated soils, which differ in both soil composition and contamination source. Soil 1 is a mix of soils with spills of transformer oils, while Soil 2 is a superficial soil from a decommissioned school where PCB were used as windows sealants. Saponin, a natural surfactant, was also tested to increase the PCB desorption from soils and enhance dechlorination. Remediation of Soil 1 (with highest pH, carbonate content, organic matter and PCB concentrations) obtained the maximum 83% and 60% PCB removal with the two-compartment and the three-compartment cell, respectively. The highest removal with Soil 2 were 58% and 45%, in the two-compartment and the three-compartment cell, respectively, in the experiments without direct current. The pH of the soil suspension in the two-compartment treatment appears to be a determining factor for the PCB dechlorination, and this cell allowed a uniform distribution of the nanoparticles in the soil, while there was iron accumulation in the injection reservoir in the three-compartment cell. Copyright © 2015 Elsevier Ltd. All rights reserved.

Regulatory T Cell Induced by Poria cocos Bark Exert Therapeutic Effects in Murine Models of Atopic Dermatitis and Food Allergy

Directory of Open Access Journals (Sweden)

Min-Jung Bae

2016-01-01

Full Text Available The prevalence of allergic disorders including atopic dermatitis (AD and food allergy (FA has increased dramatically in pediatric populations, but there is no effective drug available for their management. Therefore, trials are required for the development of safe therapeutic agents such as herbal medicines. We determined whether orally administered Poria cocos bark (PCB extract could exert immunosuppressive effects on allergic and inflammatory symptoms of AD and FA. For both AD, which was induced using house dust mite extract, and FA, which was induced by exposure to ovalbumin, model mice were orally treated with PCB extract for 62 days and 18 days, respectively. We also investigated the inductive effect of PCB extract on the generation and maintenance of Foxp3+CD4+ regulatory T cells (Tregs. The symptoms of AD and FA were ameliorated by the administration of PCB extract. Furthermore, PCB extract inhibited the Th2-related cytokines and increased the population of Foxp3+CD4+ Tregs in both AD and FA models. In ex vivo experiments, PCB extract promoted the functional differentiation of Foxp3+CD4+ Tregs, which is dependent on aryl hydrocarbon receptor activation. Thus, PCB extract has potential as an oral immune suppressor for the treatment of AD and FA through the generation of Tregs.

Dioxin-like PCB in indoor air contaminated with different sources

Energy Technology Data Exchange (ETDEWEB)

Heinzow, B.G.J.; Mohr, S.; Ostendorp, G. [Landesamt fuer Gesundheit und Arbeitssicherheit des Landes Schleswig-Holstein, Flintbek (Germany); Kerst, M.; Koerner, W. [Bayerisches Landesamt fuer Umweltschutz, Augsburg (Germany)

2004-09-15

Polychlorinated biphenyls (PCB) have been used in public building constructions for various purposes in the 1960s and 1970s, mainly as an additive to concrete, caulking, grout, paints, as a major constitutent of permanent elastic Thiokol rubber sealants and flame retardant coatings of acoustic ceiling tiles. Offgazing of semivolatile PCB from building materials can nowadays still result in considerable house-dust contamination and in indoor air concentrations exceeding 10,000 ng/m{sup 3}. In Germany, PCB levels in indoor air in non-occupational settings have been regulated with a tolerable total PCB concentration of 300 ng /m{sup 3} and an intervention level of 3000 ng/m{sup 3}. Lower re-entry criteria have been proposed by Michaud et al. Technical mixtures of PCB contain dioxin-like non- and mono-ortho substituted PCB congeners and are contaminated with trace amounts of polychlorinated dibenzodioxins (PCDD) and mainly dibenzofurans (PCDF), sharing overlapping toxic effects and physicochemical properties. We report here on levels of dioxinlike PCB measured in buildings with various PCB sources and correlations among PCDD/PCDF and dioxin-like PCB and di-ortho PCB.

Effect van PCB's op de energiekosten van migratie en bloedparameters van Europese aal

NARCIS (Netherlands)

Ginneken, van V.J.T.; Palstra, A.P.; Nieveen, M.; Berg, van den J.H.J.; Murk, A.J.

2005-01-01

Er zijn nog steeds PCB's aanwezig in het ecosysteem (water en land). Als palingen 6000 km migreren, zullen ze hun vetreserves aanspreken en komen er giftige PCB's vrij in het lichaam. Daarnaast kan de embryonale ontwikkeling nadelig beïnvloed worden door ophoping van PCB's in dooiermateriaal.

Evaluation of cumulative PCB exposure estimated by a job exposure matrix versus PCB serum concentrations

Science.gov (United States)

Ruder, Avima M.; Succop, Paul; Waters, Martha A.

2015-01-01

Although polychlorinated biphenyls (PCBs) have been banned in many countries for more than three decades, exposures to PCBs continue to be of concern due to their long half-lives and carcinogenic effects. In National Institute for Occupational Safety and Health studies, we are using semiquantitative plant-specific job exposure matrices (JEMs) to estimate historical PCB exposures for workers (n=24,865) exposed to PCBs from 1938 to 1978 at three capacitor manufacturing plants. A subcohort of these workers (n=410) employed in two of these plants had serum PCB concentrations measured at up to four times between 1976 and 1989. Our objectives were to evaluate the strength of association between an individual worker’s measured serum PCB levels and the same worker’s cumulative exposure estimated through 1977 with the (1) JEM and (2) duration of employment, and to calculate the explained variance the JEM provides for serum PCB levels using (3) simple linear regression. Consistent strong and statistically significant associations were observed between the cumulative exposures estimated with the JEM and serum PCB concentrations for all years. The strength of association between duration of employment and serum PCBs was good for highly chlorinated (Aroclor 1254/HPCB) but not less chlorinated (Aroclor 1242/LPCB) PCBs. In the simple regression models, cumulative occupational exposure estimated using the JEMs explained 14–24 % of the variance of the Aroclor 1242/LPCB and 22–39 % for Aroclor 1254/HPCB serum concentrations. We regard the cumulative exposure estimated with the JEM as a better estimate of PCB body burdens than serum concentrations quantified as Aroclor 1242/LPCB and Aroclor 1254/HPCB. PMID:23475397

Economical weight loss program for PCB-contaminated ballasts

International Nuclear Information System (INIS)

Day, B.

1995-01-01

A PCB (Polychlorinated Biphenyls) reduction process for PCB-contaminated ballasts was described. The process was developed by such organizations and programs as PCB Containment Technology Inc, and the Contech Ballast Reduction Program, and was claimed to include waste reduction of lighting ballasts down to their smallest PCB contaminated components. Particular attention was paid to the two most contaminated main components, i.e. the capacitor and the tar potting material. Development of the process and the government's role and participation therein was explained. The process of ballast reduction was said to utilize the old 'Reduce, Reuse and Recycle' theory; it was considered to be a cost effective waste reduction, recycling, and auditing alternative to incineration of PCBs

Beta decays of 126Cd and 126In to levels in 126In and 126Sn

International Nuclear Information System (INIS)

Gartner, M.L.

1979-01-01

A study of the beta decays of 126 Cd and 126 In using the TRISTAN on-line isotope separator facility is reported. Gamma-ray singles measurements were made for both decays usng Ge(Li) and LEPS (low energy photon spectrometer) detectors. In addition, gamma--gamma coincidence measurements and gamma multiscale measurements were made for both decays using Ge(Li) detectors. The half-life for 126 Cd was determined to be 0.506 +- 0.015 sec., and the half-lives for the low- and high-spin 126 In isomers were determined to be 1.83 +- 0.11 sec. and 1.96 +- 0.10 sec., respectively. A total of 11 gamma rays were observed in the decay of 126 Cd, and all but one were placed in a level scheme for 126 In. A total of 48 gamma rays were observed in the decay of the low- and high-spin 126 In isomers and all were placed in a level scheme for 126 Sn. Spin and parity assignments were deduced, whenever possible, on the basis of logft values and gamma decay selection rules. The 126 In decay schemes (one has been proposed for each isomer) are compared with earlier decay studies and with results from 124 Sn(t,p) 126 Sn reaction experiments. The systematics associated with the level schemes are discussed and a comparison is made with the nuclear shell model. 49 references

HSF1 phosphorylation by ERK/GSK3 suppresses RNF126 to sustain IGF-IIR expression for hypertension-induced cardiomyocyte hypertrophy.

Science.gov (United States)

Huang, Chih-Yang; Lee, Fa-Lun; Peng, Shu-Fen; Lin, Kuan-Ho; Chen, Ray-Jade; Ho, Tsung-Jung; Tsai, Fu-Jen; Padma, Vijaya V; Kuo, Wei-Wen; Huang, Chih-Yang

2018-02-01

Hypertension-induced cardiac hypertrophy and apoptosis are major characteristics of early-stage heart failure (HF). Inhibition of extracellular signal-regulated kinases (ERK) efficaciously suppressed angiotensin II (ANG II)-induced cardiomyocyte hypertrophy and apoptosis by blocking insulin-like growth factor II receptor (IGF-IIR) signaling. However, the detailed mechanism by which ANG II induces ERK-mediated IGF-IIR signaling remains elusive. Here, we found that ANG II activated ERK to upregulate IGF-IIR expression via the angiotensin II type I receptor (AT 1 R). ERK activation subsequently phosphorylates HSF1 at serine 307, leading to a secondary phosphorylation by glycogen synthase kinase III (GSK3) at serine 303. Moreover, we found that ANG II mediated ERK/GSK3-induced IGF-IIR protein stability by downregulating the E3 ubiquitin ligase of IGF-IIR RING finger protein CXXVI (RNF126). The expression of RNF126 decreased following ANG II-induced HSF1 S303 phosphorylation, resulting in IGF-IIR protein stability and increased cardiomyocyte injury. Inhibition of GSK3 significantly alleviated ANG II-induced cardiac hypertrophy in vivo and in vitro. Taken together, these results suggest that HSF1 phosphorylation stabilizes IGF-IIR protein stability by downregulating RNF126 during cardiac hypertrophy. ANG II activates ERK/GSK3 to phosphorylate HSF1, resulting in RNF126 degradation, which stabilizes IGF-IIR protein expression and eventually results in cardiac hypertrophy. HSF1 could be a valuable therapeutic target for cardiac diseases among hypertensive patients. © 2017 Wiley Periodicals, Inc.

PCB 28 metabolites elimination kinetics in human plasma on a real case scenario: Study of hydroxylated polychlorinated biphenyl (OH-PCB) metabolites of PCB 28 in a highly exposed German Cohort.

Science.gov (United States)

Quinete, Natalia; Esser, André; Kraus, Thomas; Schettgen, Thomas

2017-07-05

Polychlorinated biphenyls (PCBs) are suspected of carcinogenic, neurotoxic and immunotoxic effects in animals and humans. Although background levels of PCBs have been slowly decreased after their ban, they are still among the most persistent and ubiquitous pollutants in the environment, remaining the subject of great concern. PCB 28 is a trichlorinated PCB found in high concentrations not only in human plasma but also in indoor air in Europe, yet little is known about its metabolic pathway and potential metabolites in humans. The present study aims to elucidate the kinetics of metabolite formation and elimination by analyzing four hydroxylated PCBs (OH-PCBs) in human plasma as potential metabolites of the PCB 28 congener. For this purpose, the study was conducted in plasma samples of highly PCB-exposed individuals (N=268), collected from 2010 to 2014 as a representation of a real case scenario with longitudinal data. OH-PCBs have been predicted, synthesized in the course of this study and further identified and quantitated in human plasma. This is the first time that previously unknown PCB 28 metabolites have been measured in human plasma and half-lives have been estimated for PCB metabolites, which could then provide further understanding in the toxicological consequences of exposure to PCBs in humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of thiol antioxidants on the atropselective oxidation of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) by rat liver microsomes.

Science.gov (United States)

Wu, Xianai; Lehmler, Hans-Joachim

2016-02-01

Chiral polychlorinated biphenyl (PCB) congeners, such as PCB 136, are atropselectively metabolized to various hydroxylated PCB metabolites (HO-PCBs). The present study investigates the effect of two thiol antioxidants, glutathione and N-acetyl-cysteine (NAC), on profiles and chiral signatures of PCB 136 and its HO-PCB metabolites in rat liver microsomal incubations. Liver microsomes prepared from rats pretreated with phenobarbital were incubated with PCB 136 (5 μM) in the presence of the respective antioxidant (0-10 mM), and levels and chiral signatures of PCB 136 and its HO-PCB metabolites were determined. Three metabolites, 5-136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol), 4-136 (2,2',3,3',6,6'-hexachlorobiphenyl-4-ol), and 4,5-136 (2,2',3,3',6,6'-hexachlorobiphenyl-4,5-diol), were detected in all incubations, with 5-136 being the major metabolite. Compared to microsomal incubations without antioxidant, levels of 4,5-136 increased with increasing antioxidant concentration, whereas levels of PCB 136 and both mono-HO-PCBs were not affected by the presence of either antioxidant. PCB 136, 4-136, and 5-136 displayed significant atropisomeric enrichment; however, the direction and extent of the atropisomeric enrichment was not altered in the presence of an antioxidant. Because 4,5-136 can either be conjugated to a sulfate or glucuronide metabolite that is readily excreted or further oxidized a potentially toxic PCB 136 quinone, the effect of both thiol antioxidants on 4,5-136 formation suggests that disruptions of glutathione homeostasis may alter the balance between both metabolic pathways and, thus, PCB 136 toxicity in vivo.

Gender difference in walleye PCB concentrations persists following remedial dredging

Science.gov (United States)

Madenjian, Charles P.; Jude, David J.; Rediske, Richard R.; O'Keefe, James P.; Noguchi, George E.

2009-01-01

Eleven male walleyes (Sander vitreus) and 10 female walleyes from the Saginaw Bay (Lake Huron) population were caught during the spawning run at Dow Dam (Midland, Michigan) in the Tittabawassee River during April 1996, and individual whole-fish polychlorinated biphenyl (PCB) determinations were made. Total PCB concentrations averaged 7.95 and 3.17??mg/kg for males and females, respectively. As part of the Natural Resource Damage Assessment remediation process, contaminated sediments from the Saginaw River, the main tributary to Saginaw Bay, were removed during 2000 and 2001. Total PCB concentrations of 10 male and 10 female walleyes caught at Dow Dam during April 2007 averaged 1.58 and 0.55??mg/kg, respectively. Thus, dredging of the Saginaw River appeared to be effective in reducing PCB concentrations of Saginaw Bay adult walleyes, as both males and females decreased in PCB concentration by more than 80% between 1996 and 2007. However, the ratio of male PCB concentration to female PCB concentration did not decline between 1996 and 2007. This persistent gender difference in PCB concentrations was apparently due to a gender difference in habitat utilization coupled with a persistent spatial gradient in prey fish PCB concentrations from the Saginaw River to Lake Huron.

Exposure to coplanar PCBs induces endothelial cell inflammation through epigenetic regulation of NF-κB subunit p65

Energy Technology Data Exchange (ETDEWEB)

Liu, Dandan; Perkins, Jordan T. [Superfund Research Center, University of Kentucky, Lexington, KY 40536 (United States); Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40536 (United States); Petriello, Michael C. [Superfund Research Center, University of Kentucky, Lexington, KY 40536 (United States); Graduate Center for Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Hennig, Bernhard, E-mail: bhennig@uky.edu [Superfund Research Center, University of Kentucky, Lexington, KY 40536 (United States); Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40536 (United States)

2015-12-15

Epigenetic modifications of DNA and histones alter cellular phenotypes without changing genetic codes. Alterations of epigenetic marks can be induced by exposure to environmental pollutants and may contribute to associated disease risks. Here we test the hypothesis that endothelial cell dysfunction induced by exposure to polychlorinated biphenyls (PCBs) is mediated in part though histone modifications. In this study, human vascular endothelial cells were exposed to physiologically relevant concentrations of several PCBs congeners (e.g., PCBs 77, 118, 126 and 153) followed by quantification of inflammatory gene expression and changes of histone methylation. Only exposure to coplanar PCBs 77 and 126 induced the expression of histone H3K9 trimethyl demethylase jumonji domain-containing protein 2B (JMJD2B) and nuclear factor-kappa B (NF-κB) subunit p65, activated NF-κB signaling as evidenced by nuclear translocation of p65, and up-regulated p65 target inflammatory genes, such as interleukin (IL)-6, C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and IL-1α/β. The increased accumulation of JMJD2B in the p65 promoter led to a depletion of H3K9me3 repression mark, which accounts for the observed up-regulation of p65 and associated inflammatory genes. JMJD2B gene knockdown confirmed a critical role for this histone demethylase in mediating PCB-induced inflammation of the vascular endothelium. Finally, it was determined, via chemical inhibition, that PCB-induced up-regulation of JMJD2B was estrogen receptor-alpha (ER-α) dependent. These data suggest that coplanar PCBs may exert endothelial cell toxicity through changes in histone modifications. - Highlights: • Coplanar PCBs significantly induced histone demethylase JMJD2B expression. • Coplanar PCBs activated NF-κB through p65 up-regulation and nuclear translocation. • Histone H3K4 and K9 modifications were mediated by ER-α/JMJD2B/MLL2 complex. �

Automated PCB Inspection System

Directory of Open Access Journals (Sweden)

Syed Usama BUKHARI

2017-05-01

Full Text Available Development of an automated PCB inspection system as per the need of industry is a challenging task. In this paper a case study is presented, to exhibit, a proposed system for an immigration process of a manual PCB inspection system to an automated PCB inspection system, with a minimal intervention on the existing production flow, for a leading automotive manufacturing company. A detailed design of the system, based on computer vision followed by testing and analysis was proposed, in order to aid the manufacturer in the process of automation.

PCB in soils and estimated soil-air exchange fluxes of selected PCB congeners in the south of Sweden

International Nuclear Information System (INIS)

Backe, Cecilia; Cousins, Ian T.; Larsson, Per

2004-01-01

PCB concentrations were studied in different soils to determine the spatial variation over a region of approximately 11 000 km 2 . PCB congener pattern was used to illustrate the spatial differences, as shown by principal component analysis (PCA). The relationship to different soil parameters was studied. PCB concentrations in soil showed a large variation between sampling-areas with median concentrations ranging between 2.3 and 332 ng g -1 (dw). Highest concentrations were found at two sites with sandy soils, one with extremely high organic carbon content. Both sites were located on the west coast of southern Sweden. Soils with similar soil textures (i.e. sandy silt moraine) did not show any significant differences in PCB concentrations. PCB congener composition was shown to differ between sites, with congener patterns almost site-specific. PCB in air and precipitation was measured and the transfer of chemicals between the soil and air compartments was estimated. Soil-air fugacity quotient calculations showed that the PCBs in the soil consistently had a higher fugacity than the PCBs in the air, with a median quotient value of 2.7. The gaseous fluxes between soil and air were estimated using standard modelling equations and a net soil-air flux estimated by subtracting bulk deposition from gaseous soil-air fluxes. It was shown that inclusion of vertical sorbed phase transport of PCBs in the soil had a large effect on the direction of the net soil-air exchange fluxes. - Soil-air exchange of PCBs is investigated and modelled across Sweden

Integrative demographic modeling reveals population level impacts of PCB toxicity to juvenile snapping turtles

International Nuclear Information System (INIS)

Salice, Christopher J.; Rowe, Christopher L.; Eisenreich, Karen M.

2014-01-01

A significant challenge in ecotoxicology and risk assessment lies in placing observed contaminant effects in a meaningful ecological context. Polychlorinated biphenyls (PCBs) have been shown to affect juvenile snapping turtle survival and growth but the ecological significance of these effects is difficult to discern without a formal, population-level assessment. We used a demographic matrix model to explore the potential population-level effects of PCBs on turtles. Our model showed that effects of PCBs on juvenile survival, growth and size at hatching could translate to negative effects at the population level despite the fact that these life cycle components do not typically contribute strongly to population level processes. This research points to the utility of using integrative demographic modeling approaches to better understand contaminant effects in wildlife. The results indicate that population-level effects are only evident after several years, suggesting that for long-lived species, detecting adverse contaminant effects could prove challenging. -- Highlights: • Previous studies have shown the PCBs can impact juvenile snapping turtles. • We used a demographic model of turtles to evaluate population-level PCB effects. • PCB effects on turtles may translate to negative population responses. • Long-term monitoring is needed to detect contaminant effects on natural turtle populations. • Demographic models can improve our understanding contaminant ecotoxicity. -- A demographic model was used to show that PCB induced effects on young snapping turtles can result in adverse effects at the population level

Chronic treatment with polychlorinated biphenyls (PCB) during pregnancy and lactation in the rat

International Nuclear Information System (INIS)

Colciago, A.; Casati, L.; Mornati, O.; Vergoni, A.V.; Santagostino, A.; Celotti, F.; Negri-Cesi, P.

2009-01-01

The gender-specific expression pattern of aromatase and 5alpha-reductases (5alpha-R) during brain development provides neurons the right amount of estradiol and DHT to induce a dimorphic organization of the structure. Polychlorinated biphenyls (PCBs) are endocrine disruptive pollutants; exposure to PCBs through placental transfer and breast-feeding may adversely affect the organizational action of sex steroid, resulting in long-term alteration of reproductive neuroendocrinology. The study was aimed at: a) evaluating the hypothalamic expression of aromatase, 5alpha-R1 and 5alpha-R2 in fetuses (GD20), infant (PN12), weaning (PN21) and young adult (PN60) male and female rats exposed to PCBs during development; b) correlating these parameters with the time of testicular descent, puberty onset, estrous cyclicity and copulatory behavior; c) evaluating possible alterations of some non reproductive behaviors (locomotion, learning and memory, depression/anxiety behavior). A reconstituted mixture of four indicator congeners (PCB 126, 138, 153 and 180) was injected subcutaneously to dams at the dose of 10 mg/kg daily from GD15 to GD19 and then twice a week till weanling. The results indicated that developmental PCB exposure produced important changes in the dimorphic hypothalamic expression of both aromatase and the 5alpha-Rs, which were still evident in adult animals. We observed that female puberty onset occurs earlier than in control animals without cycle irregularity, while testicular descent in males was delayed. A slight but significant impairment of sexual behavior and an important alteration in memory retention were also noted specifically in males. We conclude that PCBs might affect the dimorphic neuroendocrine control of reproductive system and of other neurobiological processes.

PCB pollution continues to impact populations of orcas and other dolphins in European waters

Science.gov (United States)

Jepson, Paul D.; Deaville, Rob; Barber, Jonathan L.; Aguilar, Àlex; Borrell, Asunción; Murphy, Sinéad; Barry, Jon; Brownlow, Andrew; Barnett, James; Berrow, Simon; Cunningham, Andrew A.; Davison, Nicholas J.; Ten Doeschate, Mariel; Esteban, Ruth; Ferreira, Marisa; Foote, Andrew D.; Genov, Tilen; Giménez, Joan; Loveridge, Jan; Llavona, Ángela; Martin, Vidal; Maxwell, David L.; Papachlimitzou, Alexandra; Penrose, Rod; Perkins, Matthew W.; Smith, Brian; de Stephanis, Renaud; Tregenza, Nick; Verborgh, Philippe; Fernandez, Antonio; Law, Robin J.

2016-01-01

Organochlorine (OC) pesticides and the more persistent polychlorinated biphenyls (PCBs) have well-established dose-dependent toxicities to birds, fish and mammals in experimental studies, but the actual impact of OC pollutants on European marine top predators remains unknown. Here we show that several cetacean species have very high mean blubber PCB concentrations likely to cause population declines and suppress population recovery. In a large pan-European meta-analysis of stranded (n = 929) or biopsied (n = 152) cetaceans, three out of four species:- striped dolphins (SDs), bottlenose dolphins (BNDs) and killer whales (KWs) had mean PCB levels that markedly exceeded all known marine mammal PCB toxicity thresholds. Some locations (e.g. western Mediterranean Sea, south-west Iberian Peninsula) are global PCB “hotspots” for marine mammals. Blubber PCB concentrations initially declined following a mid-1980s EU ban, but have since stabilised in UK harbour porpoises and SDs in the western Mediterranean Sea. Some small or declining populations of BNDs and KWs in the NE Atlantic were associated with low recruitment, consistent with PCB-induced reproductive toxicity. Despite regulations and mitigation measures to reduce PCB pollution, their biomagnification in marine food webs continues to cause severe impacts among cetacean top predators in European seas.

PCB pollution continues to impact populations of orcas and other dolphins in European waters.

Science.gov (United States)

Jepson, Paul D; Deaville, Rob; Barber, Jonathan L; Aguilar, Àlex; Borrell, Asunción; Murphy, Sinéad; Barry, Jon; Brownlow, Andrew; Barnett, James; Berrow, Simon; Cunningham, Andrew A; Davison, Nicholas J; Ten Doeschate, Mariel; Esteban, Ruth; Ferreira, Marisa; Foote, Andrew D; Genov, Tilen; Giménez, Joan; Loveridge, Jan; Llavona, Ángela; Martin, Vidal; Maxwell, David L; Papachlimitzou, Alexandra; Penrose, Rod; Perkins, Matthew W; Smith, Brian; de Stephanis, Renaud; Tregenza, Nick; Verborgh, Philippe; Fernandez, Antonio; Law, Robin J

2016-01-14

Organochlorine (OC) pesticides and the more persistent polychlorinated biphenyls (PCBs) have well-established dose-dependent toxicities to birds, fish and mammals in experimental studies, but the actual impact of OC pollutants on European marine top predators remains unknown. Here we show that several cetacean species have very high mean blubber PCB concentrations likely to cause population declines and suppress population recovery. In a large pan-European meta-analysis of stranded (n = 929) or biopsied (n = 152) cetaceans, three out of four species:- striped dolphins (SDs), bottlenose dolphins (BNDs) and killer whales (KWs) had mean PCB levels that markedly exceeded all known marine mammal PCB toxicity thresholds. Some locations (e.g. western Mediterranean Sea, south-west Iberian Peninsula) are global PCB "hotspots" for marine mammals. Blubber PCB concentrations initially declined following a mid-1980s EU ban, but have since stabilised in UK harbour porpoises and SDs in the western Mediterranean Sea. Some small or declining populations of BNDs and KWs in the NE Atlantic were associated with low recruitment, consistent with PCB-induced reproductive toxicity. Despite regulations and mitigation measures to reduce PCB pollution, their biomagnification in marine food webs continues to cause severe impacts among cetacean top predators in European seas.

EFFECTS OF PCB 84 ATROPISOMERS ON [3H]-PHORBOL ESTER BINDING IN RAT CEREBELLAR GRANULE CELLS AND 45CA2+-UPTAKE IN RAT CEREBELLUM.

Science.gov (United States)

There is evidence that Polychlorinated biphenyl (PCB) congeners with ortho substituents have potential to cause neurotoxicity. Many PCB congeners implicated in these neurotoxic effects are chiral. It is currently unknown if the enantiomers of a chiral PCB congeners have differe...

Developmental exposure to an environmental PCB mixture delays the propagation of electrical kindling from the amygdala.

Science.gov (United States)

Bandara, Suren B; Sadowski, Renee N; Schantz, Susan L; Gilbert, Mary E

2017-01-01

Developmental PCB exposure impairs hearing and induces brainstem audiogenic seizures in adult offspring. The degree to which this enhanced susceptibility to seizure is manifest in other brain regions has not been examined. Thus, electrical kindling of the amygdala was used to evaluate the effect of developmental exposure to an environmentally relevant PCB mixture on seizure susceptibility in the rat. Female Long-Evans rats were dosed orally with 0 or 6mg/kg/day of the PCB mixture dissolved in corn oil vehicle 4 weeks prior to mating and continued through gestation and up until postnatal day (PND) 21. On PND 21, pups were weaned, and two males from each litter were randomly selected for the kindling study. As adults, the male rats were implanted bilaterally with electrodes in the basolateral amygdala. For each animal, afterdischarge (AD) thresholds in the amygdala were determined on the first day of testing followed by once daily stimulation at a standard 200μA stimulus intensity until three stage 5 generalized seizures (GS) ensued. Developmental PCB exposure did not affect the AD threshold or total cumulative AD duration, but PCB exposure did increase the latency to behavioral manifestations of seizure propagation. PCB exposed animals required significantly more stimulations to reach stage 2 seizures compared to control animals, indicating attenuated focal (amygdala) excitability. A delay in kindling progression in the amygdala stands in contrast to our previous finding of increased susceptibility to brainstem-mediated audiogenic seizures in PCB-exposed animals in response to a an intense auditory stimulus. These seemingly divergent results are not unexpected given the distinct source, type, and mechanistic underpinnings of these different seizure models. A delay in epileptogenesis following focal amygdala stimulation may reflect a decrease in neuroplasticity following developmental PCB exposure consistent with reductions in use-dependent synaptic plasticity that

Laboratory test of source encapsulation for decreasing PCB concentrations

DEFF Research Database (Denmark)

Kolarik, Barbara; Andersen, Helle Vibeke; Markowicz, Pawel

2016-01-01

This study investigates the effect of encapsulation of tertiary PCB sources with PERMASORB™ Adsorber Wallpaper and the surface emissions trap (cTrap) on indoor air concentration of PCBs and on the PCB content in the source. The 40 weeks long laboratory investigation shows reduction of the air...... concentration by approx. 90% for both wallpapers, a level comparable to source removal. The potential for extraction of PCBs from the contaminated materials stays unclear for both wallpapers. The cTrap has shown potential to accumulate PCBs, however the total content of PCB in investigated sources has...... apparently increased. The opposite was observed for the PERMASORB™, where the total PCB content in the sources has decreased, with however only small concentration of PCBs in the wallpaper measured at the end of the experiment....

Effects of in ovo exposure to 3,3',4,4'-tetrachlorobiphenyl (PCB 77) on heart development in tree swallow (Tachycineta bicolor).

Science.gov (United States)

Carro, Tiffany; Walker, Mary K; Dean, Karen M; Ottinger, Mary Ann

2018-01-01

Tree swallow (Tachycineta bicolor) eggs from 2 uncontaminated sites, the Patuxent Research Refuge (Laurel, MD, USA) and the Cobleskill Reservoir (Cobleskill, NY, USA) were dosed with polychlorinated biphenyl (PCB) 77 to evaluate effects on the developing cardiovascular system. To ensure embryonic viability, treatments were administered into the air cell at embryonic day 2.5 including: untreated (control), vehicle (filtered sterilized fatty acid mixture), 100 ng/g and 1000 ng/g egg. Eggs were dosed in the field with 0.2 μL/egg, returned to the nest, collected at embryonic day 13, hatched in the laboratory, and necropsied. The PCB 77-treated hatchlings were compared with uninjected, vehicle-injected, and environmentally exposed hatchlings collected from a PCB-contaminated Upper Hudson River (NY, USA) site. The PCB 77-treated embryos showed no effects on hatching success or hatchling mortality, heart index, or morphological measures of 4 distinct heart layers (heart width, length, septal thickness, total and ventricular cavity area) compared with controls. Hatchlings that had received PCB 77 exhibited increased incidence of a cardiomyopathy and absence of the ventricular heart wall compact layer (Chi square test; p PCB 77 resulted in distinct cardiomyopathy has implications for long-term individual fitness. Environ Toxicol Chem 2018;37:116-125. © 2017 SETAC. © 2017 SETAC.

PCB Fault Detection Using Image Processing

Science.gov (United States)

Nayak, Jithendra P. R.; Anitha, K.; Parameshachari, B. D., Dr.; Banu, Reshma, Dr.; Rashmi, P.

2017-08-01

The importance of the Printed Circuit Board inspection process has been magnified by requirements of the modern manufacturing environment where delivery of 100% defect free PCBs is the expectation. To meet such expectations, identifying various defects and their types becomes the first step. In this PCB inspection system the inspection algorithm mainly focuses on the defect detection using the natural images. Many practical issues like tilt of the images, bad light conditions, height at which images are taken etc. are to be considered to ensure good quality of the image which can then be used for defect detection. Printed circuit board (PCB) fabrication is a multidisciplinary process, and etching is the most critical part in the PCB manufacturing process. The main objective of Etching process is to remove the exposed unwanted copper other than the required circuit pattern. In order to minimize scrap caused by the wrongly etched PCB panel, inspection has to be done in early stage. However, all of the inspections are done after the etching process where any defective PCB found is no longer useful and is simply thrown away. Since etching process costs 0% of the entire PCB fabrication, it is uneconomical to simply discard the defective PCBs. In this paper a method to identify the defects in natural PCB images and associated practical issues are addressed using Software tools and some of the major types of single layer PCB defects are Pattern Cut, Pin hole, Pattern Short, Nick etc., Therefore the defects should be identified before the etching process so that the PCB would be reprocessed. In the present approach expected to improve the efficiency of the system in detecting the defects even in low quality images

Oxidative stress and apoptosis of Carassius auratus lymphocytes induced by nonplanar (PCB153) and coplanar (PCB169) polychlorinated biphenyl congeners in vitro

Institute of Scientific and Technical Information of China (English)

ZHANG Jian-ying; ZHANG Hang-jun; NI Wan-min

2009-01-01

and the coplanar congener was more cytotoxic than nonplanar congener. This study suggests that cytotoxicity mechanisms of the PCB congeners on fish lymphocytes depend on their planarity and chemical structures.

In Vitro Exposure of Porcine Ovarian Follicular Cells to PCB 153 Alters Steroid Secretion But Not Their Viability—Preliminary Study

Directory of Open Access Journals (Sweden)

Ewa L. Gregoraszczuk

2002-01-01

Full Text Available In our previous paper[1], we demonstrated that porcine follicles collected during the early stage of development are the most sensitive to the toxic action of polychlorinated biphenyl 153 (PCB 153. Follicles of this type were collected to test the effect of PCB 153 on cell steroidogenesis and viability. Cocultures of granulosa and theca cells were grown in M199 medium at 37ºC. Control cultures were maintained in that medium alone, while experimental ones were supplemented with PCB 153 at doses of 5, 10, 50, and 100 ng/ml. After 48, 96, and 144 h, media were collected for steroid analysis and cell viability was measured using an LDH (lactate dehydrogenase activity cytotoxicity test. A 2-day exposure of follicular cells to all the investigated doses of PCB 153 caused a statistically significant decrease in progesterone (P4 secretion, while in doses of 50 and 100 ng/ml there was also a decrease in testosterone (T secretion. No effect on estradiol (E2 secretion was observed. The observed decrease in P4 and T secretion, and lack of any statistically significant effect on E2 secretion by cells from small follicles exposed for 48 h to PCB, suggests that PCB 153 acts before P4 formation. Longer exposures caused an increase in P4 secretion, with a concomitant drastic decrease in T secretion and a tendency to decrease the E2 secretion, suggesting inhibition of P450 17α hydroxysteroid dehydrogenase, an enzyme that converts P4 to T. The observed PCB 153–induced increase in P4 secretion by cells collected from small antral follicles, with a concomitant decrease in E2 secretion, accounts for the induction of luteinization and, in this case, inhibition of aromatization process in the follicles. However, in all doses tested and at all times of exposure, PCB 153 had no effect on cell viability. These findings suggest different time of exposure–dependent action of PCB 153 on particular steps of steroidogenesis but not action on cell viability. These results

Do fish growth rates correlate with PCB body burdens?

Science.gov (United States)

Andrew L. Rypel; David R.. Bayne

2010-01-01

We evaluated whether growth rates of six fish species correlated with PCB concentrations in a moderately-to-heavily polluted freshwater ecosystem. Using a large dataset (n ¼ 984 individuals), and after accounting for growth effects related to fish age, habitat, sex, and lipids, growth correlated significantly, but positively with lipid-corrected PCB concentrations for...

Mono-, di-, and trichlorinated biphenyls (PCB 1-PCB 39) in the indoor air of office rooms and their relevance on human blood burden.

Science.gov (United States)

Kraft, M; Sievering, S; Grün, L; Rauchfuss, K

2018-05-01

Exposure to polychlorinated biphenyls (PCBs) from indoor air can lead to a significant increase in lower chlorinated congeners in human blood. Lower chlorinated congeners with short biological half-lives can exhibit an indirect genotoxic potential via their highly reactive metabolites. However, little is known about their occurrence in indoor air and, therefore, about the effects of possible exposure to these congeners. We analyzed all mono-, di-, and trichlorinated biphenyls in the indoor air of 35 contaminated offices, as well as in the blood of the 35 individuals worked in these offices for a minimum of 2 years. The median concentration of total PCB in the indoor air was 479 ng/m 3 . The most prevalent PCBs in the indoor air samples were the trichlorinated congeners PCB 31, PCB 18, and PCB 28, with median levels of 39, 31, and 26 ng/m 3 , respectively. PCB 8 was the most prevalent dichlorinated congener (median: 9.1 ng/m 3 ). Monochlorinated biphenyls were not detected in relevant concentrations. In the blood samples, the most abundant congener was PCB 28; nearly 90% of all mono-, di-, and trichlorinated congeners were attributed to this congener (median: 12 ng/g blood lipid). © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Early weaning PCB 95 exposure alters the neonatal endocrine system: thyroid adipokine dysfunction.

Science.gov (United States)

Ahmed, R G

2013-12-01

Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that can severely disrupt the endocrine system. In the present study, early-weaned male rats were administered a single dose of 2,3,6-2',5'-pentachlorinated biphenyl (PCB 95; 32 mg/kg per day, by i.p. injection) for two consecutive days (postnatal days (PNDs) 15 and 16) and killed 24 and 48 h after the administration of the last dose. Compared with the control group, administration of PCB 95 induced a reduction (Pcolloidal contents at PND 18. The dyshormonogenesis and thyroid dysgenesis may be attributed to the elevation of DNA fragmentation at PNDs 17 and 18. Furthermore, this hypothyroid state revealed higher (Pinsulin at both PNDs compared with the control group. Interestingly, the body weight of the neonates in the PCB 95 group exhibited severe decreases throughout the experimental period in relation to that of the control group. These results imply that PCB 95 may act as a disruptor of the developmental hypothalamic-pituitary-thyroid axis. Hypothyroidism caused by PCB 95 may impair the adipokine axis, fat metabolism, and in general postnatal development. Thus, further studies need to be carried out to understand this concept.

Cyp1a-dependent activation of xenobiotics in endothelial linings of the chorioallantoic membrane (CAM) in birds

Energy Technology Data Exchange (ETDEWEB)

Annas, A.; Brittebo, E.B. [Uppsala Univ. (Sweden). Dept. of Toxicology; Brunstroem, B. [Dept. of Environmental Toxicology, Uppsala Univ., Uppsala (Sweden)

2000-08-01

Metabolic activation of the heterocyclic amine 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 7-ethoxyresorufin O-deethylase (EROD) activity were examined in the chorioallantoic membrane (CAM) of 15-day-old chicken and 18-day-old eider duck embryos. The embryos were pretreated with an Ah receptor agonist, i.e. {beta}-naphthoflavone (BNF) or 3,3',4,4',5-pentachlorobiphenyl (PCB 126), or vehicle in ovo. BNF and PCB 126 induced EROD activity and covalent binding of [{sup 3}H]Trp-P-1 seven- to tenfold in the CAM of chicken embryos. In the CAM of eider duck embryos, which are known to be nonresponsive to coplanar PCBs, PCB 126 treatment had no effect on EROD activity or covalent binding of [{sup 3}H]Trp-P-1 whereas BNF treatment increased these activities five- and threefold, respectively. Light microscopic autoradiography was used to identify the cellular localization of covalent binding of [{sup 3}H]Trp-P-1 in the CAM. Preferential binding was observed in endothelial cells in intraepithelial capillaries in the chorionic epithelium and in blood vessels in the mesenchymal layer. The addition of the CYP1A inhibitor ellipticine abolished the covalent binding of [{sup 3}H]Trp-P-1 in the CAM of BNF- and PCB 126-treated chicken and eider duck embryos. The results suggest that CYP1A-dependent metabolic activity can be induced in blood vessel endothelia in the CAM of bird embryos following exposure to Ah receptor agonists and that the CAM may be a target tissue for CYP1A-activated environmental pollutants. Furthermore, the highly vascularized CAM could be used as a model for studies of Ah receptor-mediated alterations in the vasculature. (orig.)

Cyp1a-dependent activation of xenobiotics in endothelial linings of the chorioallantoic membrane (CAM) in birds

International Nuclear Information System (INIS)

Annas, A.; Brittebo, E.B.

2000-01-01

Metabolic activation of the heterocyclic amine 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 7-ethoxyresorufin O-deethylase (EROD) activity were examined in the chorioallantoic membrane (CAM) of 15-day-old chicken and 18-day-old eider duck embryos. The embryos were pretreated with an Ah receptor agonist, i.e. β-naphthoflavone (BNF) or 3,3',4,4',5-pentachlorobiphenyl (PCB 126), or vehicle in ovo. BNF and PCB 126 induced EROD activity and covalent binding of [ 3 H]Trp-P-1 seven- to tenfold in the CAM of chicken embryos. In the CAM of eider duck embryos, which are known to be nonresponsive to coplanar PCBs, PCB 126 treatment had no effect on EROD activity or covalent binding of [ 3 H]Trp-P-1 whereas BNF treatment increased these activities five- and threefold, respectively. Light microscopic autoradiography was used to identify the cellular localization of covalent binding of [ 3 H]Trp-P-1 in the CAM. Preferential binding was observed in endothelial cells in intraepithelial capillaries in the chorionic epithelium and in blood vessels in the mesenchymal layer. The addition of the CYP1A inhibitor ellipticine abolished the covalent binding of [ 3 H]Trp-P-1 in the CAM of BNF- and PCB 126-treated chicken and eider duck embryos. The results suggest that CYP1A-dependent metabolic activity can be induced in blood vessel endothelia in the CAM of bird embryos following exposure to Ah receptor agonists and that the CAM may be a target tissue for CYP1A-activated environmental pollutants. Furthermore, the highly vascularized CAM could be used as a model for studies of Ah receptor-mediated alterations in the vasculature. (orig.)

EFFECTS OF THIOL ANTIOXIDANTS ON THE ATROPSELECTIVE OXIDATION OF 2,2′,3,3′,6,6′-HEXACHLOROBIPHENYL (PCB 136) BY RAT LIVER MICROSOMES

Science.gov (United States)

Wu, Xianai; Lehmler, Hans-Joachim

2015-01-01

Chiral polychlorinated biphenyl (PCB) congeners, such as PCB 136, are atropselectively metabolized to various hydroxylated PCB metabolites (HO-PCBs). The present study investigates the effect of two thiol antioxidants, glutathione and N-acetyl-cysteine (NAC), on profiles and chiral signatures of PCB 136 and its HO-PCB metabolites in rat liver microsomal incubations. Liver microsomes prepared from rats pretreated with phenobarbital were incubated with PCB 136 (5 μM) in the presence of the respective antioxidant (0–10 mM), and levels and chiral signatures of PCB 136 and its HO-PCB metabolites were determined. Three metabolites, 5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol), 4-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4-ol) and 4,5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4,5-diol), were detected in all incubations, with 5-136 being the major metabolite. Compared to microsomal incubations without antioxidant, levels of 4,5-136 increased with increasing antioxidant concentration, whereas levels of PCB 136 and both mono-HO-PCBs were not affected by the presence of either antioxidant. PCB 136, 4-136 and 5-136 displayed significant atropisomeric enrichment; however, the direction and extent of the atropisomeric enrichment was not altered in the presence of an antioxidant. Because 4,5-136 can either be conjugated to a sulfate or glucuronide metabolite that is readily excreted or further oxidized a potentially toxic PCB 136 quinone, the effect of both thiol antioxidants on 4,5-136 formation suggests that disruptions of glutathione homeostasis may alter the balance between both metabolic pathways and, thus, PCB 136 toxicity in vivo. PMID:26155892

An assessment of PCB degradation by microogransims including methods for measuring mineralization

International Nuclear Information System (INIS)

Hadden, C.; Edenborn, H.; Osborne, T.; Holdsworth, G.; Revis, N.

1990-01-01

These studies sought to isolate and identify organism(s) from PCB contaminated soil and sediment that degrade PCB; to provide information on the potential of organisms in soil samples taken from a PCB-contaminated area to mineralize or dechlorinate PCB congeners; to assess potential enhancement of PCB biodegradation as a result of nutritional amendment of the samples; and to carry out analyses of successive lysimeter samples to determine whether field treatments have had an effect on the capacity of soil microbes to mineralize PCBS. We have expended considerable effort to validate the fractionation procedure used to assess mineralization and conversion of PCB substrates. The assessment relies on the ability to measure [ 14 C]-labeled CO 2 in the presence of potentially volatile [ 14 C]-labeled PCB and degradation products to differentiate between volatile and non-volatile [ 14 C]-labeled compounds between water-soluble products of metabolism and a mixture of unchanged substrate and other water-insoluble products and between metabolism and loss or non-extractability of the substrate

An assessment of PCB degradation by microogransims including methods for measuring mineralization

Energy Technology Data Exchange (ETDEWEB)

Hadden, C.; Edenborn, H.; Osborne, T.; Holdsworth, G.; Revis, N.

1990-12-31

These studies sought to isolate and identify organism(s) from PCB contaminated soil and sediment that degrade PCB; to provide information on the potential of organisms in soil samples taken from a PCB-contaminated area to mineralize or dechlorinate PCB congeners; to assess potential enhancement of PCB biodegradation as a result of nutritional amendment of the samples; and to carry out analyses of successive lysimeter samples to determine whether field treatments have had an effect on the capacity of soil microbes to mineralize PCBS. We have expended considerable effort to validate the fractionation procedure used to assess mineralization and conversion of PCB substrates. The assessment relies on the ability to measure [{sup 14}C]-labeled CO{sub 2} in the presence of potentially volatile [{sup 14}C]-labeled PCB and degradation products to differentiate between volatile and non-volatile [{sup 14}C]-labeled compounds between water-soluble products of metabolism and a mixture of unchanged substrate and other water-insoluble products and between metabolism and loss or non-extractability of the substrate.

Radiation dechlorination of PCE and PCB in the quarter operation flow apparatus

International Nuclear Information System (INIS)

Mucka, V.; Silber, R.; Pospisil, M.; Camra, M.; Bartonicek, B.

1999-01-01

The aim of this work was to verify practical possibilities of radiation dechlorination of liquid chlorinated substrates [perchloroethylene (PCE) and polychlorinated biphenyls (PCB)] in the quarter operation flow apparatus. In this apparatus may be disposable work over 50 dm 3 of media. Radiation dechlorination of PCE proceeds more effectively as dechlorination of PCB in flow regimes, too. Radiation chemical yield of G(-OH - ) decrease with increasing applied radiation dose and at the dose 5 kGy for PCE it is 200 · 10 -2 eV -1 and for PCB this value is 55 · 10 -2 eV -1 . At increasing original concentration of PCE or PCB the G-values decreases. The radical chain mechanism of dechlorination of PCE and PCB was proposed

Total destruction of PCB transformers

International Nuclear Information System (INIS)

Myers, D.S.

1991-01-01

This paper reports that if elimination of PCB liability, including lingering liabilities, is the goal, then landfilling cannot be and option. The law is clear that the generator of PCB waste is responsible for that waste until this destruction. Landfilling is not destruction. Retrofilling as askarel units will not get rid of all PCB liabilities, either. Askarel retrofilling can only make this claim when it can give a lifetime guaranty of no detectable PCBs. States like Washington and California regulate, as hazardous waste, fluids which contain greater than 2 and 5 ppm PCB, respectively. There is no guarantee that your state will not so regulate PCBs in the future or that the federal laws might tighten up. Therefore, replacement and disposal by Resource Recovery constitutes the only lifetime guarantee on the market that the PCBs in your askarel transformers will never come back to haunt you

Assessment of LANL PCB waste management documentation

International Nuclear Information System (INIS)

David, K.D.; Hoevemeyer, S.S.; Stirrup, T.S.; Jennrich, E.A.; Lund, D.M.

1991-04-01

The objective of this report is to present findings from evaluating the Los Alamos National Laboratory (LANL) Polychlorinated Biphenyls (PCB) Waste Acceptance Criteria (WAC) to determine if it meets applicable DOE and Code of Federal Regulation (CFR) requirements. DOE Order 5820.2A and 40 CFR 761 (Polychlorinated Biphenyls Manufacturing, Processing, Distribution in Commerce, and Use Prohibitions) set forth requirements and guidelines for the establishment of Waste Acceptance Criteria. The primary purpose of a PCB WAC is to provide generators and waste management with established criteria that must be met before PCB wastes can be accepted for treatment, storage, and/or disposal. An annotated outline for a generic PCB WAC was developed based on the requirements of 5820.2A and 40 CFR 761. The major elements that should be addressed by a PCB WAC were determined to be as follows: Waste Package/Container, Waste Forms, PCB Concentrations, Labeling, and Data Package Certification

Carcinogenicity/tumour promotion by NDL PCB

Energy Technology Data Exchange (ETDEWEB)

Schrenk, D. [Kaiserslautern Univ. (Germany). Food Chemistry and Environmental Toxicology

2004-09-15

Polychlorinated biphenyls (PCBs) belong to the group of persistent environmental pollutants exhibiting neurotoxic, teratogenic and tumour-promoting effects in experimental animal models. PCB congeners can be divided into 'dioxinlike' and 'non-dioxinlike' congeners on the basis of their ability to act as aryl hydrocarbon receptor (AhR) agonists. Like the most toxic dioxin congener 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) 'dioxinlike' PCBs bind to the AhR and show characteristic effects on the expression of AhR-regulated genes including the induction of cytochrome P450 (CYP) 1A1. On the other hand, 'non-dioxinlike' PCB congeners have a lower or no binding affinity to the AhR, but exhibit a 'phenobarbital-type' induction of CYP 2B1/2 activity. A carcinogenic potential of PCBs has been demonstrated with technical mixtures such as Aroclors or Clophens. In these studies the liver and the thyroid gland were found to be the principal target organs of PCB-mediated carcinogenesis in rodents. No studies have been published, however, on the carcinogenicity of individual congeners. In two-stage initiation-promotion protocols in rats, both technical mixtures and individual 'dioxinlike' and 'non-dioxinlike' congeners were reported to act as liver tumour promoters.

miR-126 Regulation of Angiogenesis in Age-Related Macular Degeneration in CNV Mouse Model

Directory of Open Access Journals (Sweden)

Lei Wang

2016-06-01

Full Text Available miR-126 has recently been implicated in modulating angiogenic factors in vascular development. Understandings its biological significance might enable development of therapeutic interventions for diseases like age-related macular degeneration (AMD. We aimed to determine the role of miR-126 in AMD using a laser-induced choroidal neovascularization (CNV mouse model. CNV was induced by laser photocoagulation in C57BL/6 mice. The CNV mice were transfected with scrambled miR or miR-126 mimic. The expression of miR-126, vascular endothelial growth factor-A (VEGF-A, Kinase insert domain receptor (KDR and Sprouty-related EVH1 domain-containing protein 1 (SPRED-1 in ocular tissues were analyzed by qPCR and Western blot. The overexpression effects of miR-126 were also proven on human microvascular endothelial cells (HMECs. miR-126 showed a significant decrease in CNV mice (p < 0.05. Both mRNA and protein levels of VEGF-A, KDR and SPRED-1 were upregulated with CNV; these changes were ameliorated by restoration of miR-126 (p < 0.05. CNV was reduced after miR-126 transfection. Transfection of miR-126 reduced the HMECs 2D-capillary-like tube formation (p < 0.01 and migration (p < 0.01. miR-126 has been shown to be a negative modulator of angiogenesis in the eye. All together these results high lights the therapeutic potential of miR-126 suggests that it may contribute as a putative therapeutic target for AMD in humans.

Induced Proton Polarization for pi0 Electroproduction at Q2 = 0.126 GeV2/c2 Around the Delta(1232) Resonance

International Nuclear Information System (INIS)

Glen Warren; Ricardo Alarcon; Christopher Armstrong; Burin Asavapibhop; David Barkhuff; William Bertozzi; Volker Burkert; Chen, J.; Jian-Ping Chen; Joseph Comfort; Daniel Dale; George Dodson; Dolfini, S.; Dow, K.; Martin Epstein; Manouchehr Farkhondeh; John Finn; Shalev Gilad; Ralf Gothe; Xiaodong Jiang; Mark Jones; Kyungseon Joo; Karabarbounis, A.; James Kelly; Stanley Kowalski; Kunz, C.; Liu, D.; Lourie, R.W.; Richard Madey; Demetrius Margaziotis; Pete Markowitz; Justin McIntyre; Mertz, C.; Brian Milbrath; Rory Miskimen; Joseph Mitchell; Mukhopadhyay, S.; Costas Papanicolas; Charles Perdrisat; Vina Punjabi; Liming Qin; Paul Rutt; Adam Sarty; Jeffrey Shaw; Soong, S.B.; Tieger, D.; Christoph Tschalaer; William Turchinetz; Paul Ulmer; Scott Van Verst; Vellidis, C.; Lawrence Weinstein; Steven Williamson; Rhett Woo; Alaen Young

1998-01-01

We present a measurement of the induced proton polarization P n in π 0 electroproduction on the proton around the Δ resonance. The measurement was made at a central invariant mass and a squared four-momentum transfer of W = 1231 MeV and Q 2 = 0.126 GeV 2 /c 2 , respectively. We measured a large induced polarization, P n = -0.397 ± 0.055 ± 0.009. The data suggest that the scalar background is larger than expected from a recent effective Hamiltonian model

Recent changes in federal PCB regulations

International Nuclear Information System (INIS)

Ewing, H.

1995-01-01

An overview of the federal regulations dealing with PCBs, the draft PCB Transformer Decontamination Standards and Protocols, and the Practice of Ballast Splitting was given. Answers were provided to practical questions concerning the regulations, specifically, responsibility for storage, labelling requirements, waste export regulations, treatment and destruction standards, transformer decontamination, decontamination standards, and the practice of ballast splitting into PCB and non-PCB materials. Details of sampling procedures and sample handling were also described

40 CFR 761.61 - PCB remediation waste.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false PCB remediation waste. 761.61 Section... PROHIBITIONS Storage and Disposal § 761.61 PCB remediation waste. This section provides cleanup and disposal options for PCB remediation waste. Any person cleaning up and disposing of PCBs managed under this section...

Multiple mechanisms of PCB neurotoxicity

Energy Technology Data Exchange (ETDEWEB)

Carpenter, D.O.; Stoner, C.T.; Lawrence, D.A. [Univ. of New York, Albany, NY (United States)] [and others

1996-12-31

Polychlorinated biphenyls (PCBs) have been implicated in cancer, but many of the symptoms in humans exposed to PCBs are related to the nervous system and behavior. We demonstrated three different direct mechanisms whereby PCBs are neurotoxic in rats. By using flow cytometry, we demonstrated that the orthosubstituted PCB congener 2,4,4{prime}, but neither TCDD nor the coplanar PCB congener 3,4,5,3{prime},4{prime}, causes rapid death of cerebellar granule cells. The ortho-substituted congener 2,4,4{prime} reduced long-term potentiation, an indicator of cognitive potential, in hippocampal brain slices, but a similar effect was observed for the coplanar congener 3,4,3{prime},4{prime}, indicating that this effect may be caused by both ortho- and coplanar congeners by mechanisms presumably not mediated via the Ah receptor. It was previously shown that some ortho-substituted PCB congeners cause a reduction in levels of the neurotransmitter dopamine, and we present in vitro and in vivo evidence that this is due to reduction of synthesis of dopamine via inhibition of the enzyme tyrosine hydroxylase. Thus, PCBs have a variety of mechanisms of primary neurotoxicity, and neurotoxicity is a characteristic of ortho-substituted, non-dioxin-like congeners as well as some coplanar congeners. The relative contribution of each of these mechanisms to the loss of cognitive function in humans exposed to PCBs remains to be determined. 42 refs., 3 figs., 1 tab.

The neurotoxicant PCB-95 by increasing the neuronal transcriptional repressor REST down-regulates caspase-8 and increases Ripk1, Ripk3 and MLKL expression determining necroptotic neuronal death.

Science.gov (United States)

Guida, Natascia; Laudati, Giusy; Serani, Angelo; Mascolo, Luigi; Molinaro, Pasquale; Montuori, Paolo; Di Renzo, Gianfranco; Canzoniero, Lorella M T; Formisano, Luigi

2017-10-15

associated with reduced promoter activity of the RIPK1, RIPK3 and MLKL genes. Collectively, these results indicate that PCB-95 was associated with REST-induced necroptotic cell death by increasing RIPK1, RIPK3 and MLKL expression and reducing caspase-8 levels. In addition, since REST is involved in several neurological disorders, therapies that block REST-induced necroptosis could be a new strategy to revert the neurodetrimental effects associated to its overexpression. Copyright © 2017 Elsevier Inc. All rights reserved.

New EPA ban stymies Canadian exports of PCB waste

International Nuclear Information System (INIS)

Anon.

1997-01-01

With reference to a 1996 EPA ruling permitting the importation to the USA of PCBs for incineration, a unanimous three-judge panel of the US Court of Appeals for the Ninth District in San Francisco ruled that the Environmental Protection Agency (EPA) did not have the authority to permit the import of PCB wastes into the USA for disposal. Prior to the decision, 35 applications from Canada to export some 37,000 tonnes of PCB to the USA for disposal have been approved. Canadian brokers are upset with the decision, claiming that the decision will create a virtual monopoly for Bovar Inc., of Calgary, the only PCB-disposal facility in Canada. The loss (at least for the time being) of the alternate disposal opportunity will likely have the effect of forcing Canadian customers to pay more for PCB disposal. The Canadian government is monitoring the situation and is waiting to see whether an appeal is filed against the ruling

The effect of ventilation on the indoor air concentration of PCB

DEFF Research Database (Denmark)

Lyng, Nadja; Gunnarsen, Lars Bo; Andersen, Helle Vibeke

2015-01-01

The impact of increased ventilation on polychlorinated biphenyl (PCB) air concentration by installation of mechanical balanced ventilation units was studied. The intervention was carried out in three PCB-contaminated rooms; one classroom in an elementary school and two small bedrooms...... in an apartment in a residential building. In the classroom, the air exchange rate (ACH) was raised from 0.2 (without mechanical ventilation) to 5.5 /h during the intervention. In the two bedrooms, the highest ACH was 6.6 /h and 0.5 /h without mechanical ventilation. The corresponding concentration decrease...

Differences in energy expenditures and growth dilution explain higher PCB concentrations in male summer flounder

Science.gov (United States)

Madenjian, Charles P.; Jensen, Olaf P.; Rediske, Richard R.; O'Keefe, James P.; Vastano, Anthony R.; Pothoven, Steven A.

2016-01-01

Comparison of polychlorinated biphenyl (PCB) concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes.

Differences in Energy Expenditures and Growth Dilution Explain Higher PCB Concentrations in Male Summer Flounder.

Directory of Open Access Journals (Sweden)

Charles P Madenjian

Full Text Available Comparison of polychlorinated biphenyl (PCB concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes.

The Environmental Neurotoxicant PCB 95 Promotes Synaptogenesis via Ryanodine Receptor-Dependent miR132 Upregulation

Science.gov (United States)

Lesiak, Adam; Zhu, Mingyan; Chen, Hao; Appleyard, Suzanne M.; Impey, Soren; Wayman, Gary A.

2014-01-01

Non–dioxin-like (NDL) polychlorinated biphenyls (PCBs) are widespread environmental contaminants linked to neuropsychological dysfunction in children. NDL PCBs increase spontaneous Ca2+ oscillations in neurons by stabilizing ryanodine receptor (RyR) calcium release channels in the open configuration, which results in CREB-dependent dendritic outgrowth. In this study, we address the question of whether activation of CREB by NDL PCBs also triggers dendritic spine formation. Nanomolar concentrations of PCB 95, a NDL congener with potent RyR activity, significantly increased spine density and the frequency of miniature EPSCs in primary dissociated rat hippocampal cultures coincident with upregulation of miR132. Inhibition of RyR, CREB, or miR132 as well as expression of a mutant p250GAP cDNA construct that is not suppressed by miR132 blocked PCB 95 effects on spines and miniature EPSCs. PCB 95 also induced spine formation via RyR- and miR132-dependent mechanisms in hippocampal slice cultures. These data demonstrate a novel mechanism of PCB developmental neurotoxicity whereby RyR sensitization modulates spine formation and synaptogenesis via CREB-mediated miR132 upregulation, which in turn suppresses the translation of p250GAP, a negative regulator of synaptogenesis. In light of recent evidence implicating miR132 dysregulation in Rett syndrome and schizophrenia, these findings identify NDL PCBs as potential environmental risk factors for neurodevelopmental disorders. PMID:24431430

PCB exposure and cochlear function at age 6 years.

Science.gov (United States)

Palkovičová Murínová, Ľubica; Moleti, Arturo; Sisto, Renata; Wimmerová, Soňa; Jusko, Todd A; Tihányi, Juraj; Jurečková, Dana; Kováč, Ján; Koštiaková, Vladimíra; Drobná, Beata; Trnovec, Tomáš

2016-11-01

Epidemiological studies have documented adverse associations between exposure to polychlorinated biphenyls (PCBs) and otological outcomes. Previously, we documented decreased distortion product otoacoustic emission (DPOAE) levels in children exposed to PCBs, up to the age of 45 months, amongst a cohort of children in eastern Slovakia. The objective of the present study is to evaluate cochlear dysfunction at 72 months of age in 214 children from this same cohort and to compare the otoacoustic test sensitivity to that of pure tone audiometry (PTA). The association between DPOAE, PTA, and PCBs was estimated by means of multivariate ANOVA (MANOVA) and linear regression models. ROC curves were computed to estimate the DPOAE-test power in children. The DPOAE level at 72 months was related to PCB-153 serum levels. The DPOAE Input/Output function test at mid-frequency (2kHz) has shown instead nonmonotonic dependence on PCB exposure, for the left ears of children, over the whole growth curve. No significant association was found between PTA hearing levels and PCB-153 concentration. High diagnostic power of the DPOAE-test was found in children, similar to that found by the same authors in adults. In conclusions the DPOAE-PCB correlation obtained at 72 months is similar to that at 45 months suggesting a permanent and stable ototoxic effect of the PCB exposure. The lack of statistical significance of the PCB-PTA correlation suggests that DPOAEs are sensitive biomarkers of cochlear damage. Copyright © 2016 Elsevier Inc. All rights reserved.

Prenatal and postnatal serum PCB concentrations and cochlear function in children at 45 months of age.

Science.gov (United States)

Jusko, Todd A; Sisto, Renata; Iosif, Ana-Maria; Moleti, Arturo; Wimmerová, Sonˇa; Lancz, Kinga; Tihányi, Juraj; Sovčiková, Eva; Drobná, Beata; Palkovičová, L'ubica; Jurečková, Dana; Thevenet-Morrison, Kelly; Verner, Marc-André; Sonneborn, Dean; Hertz-Picciotto, Irva; Trnovec, Tomáš

2014-11-01

Some experimental and human data suggest that exposure to polychlorinated biphenyls (PCBs) may induce ototoxicity, though results of previous epidemiologic studies are mixed and generally focus on either prenatal or postnatal PCB concentrations exclusively. Our aim was to evaluate the association between pre- and postnatal PCB concentrations in relation to cochlear status, assessed by distortion product otoacoustic emissions (DPOAEs), and to further clarify the critical periods in development where cochlear status may be most susceptible to PCBs. A total of 351 children from a birth cohort in eastern Slovakia underwent otoacoustic testing at 45 months of age. Maternal pregnancy, cord, and child 6-, 16-, and 45-month blood samples were collected and analyzed for PCB concentrations. At 45 months of age, DPOAEs were assessed at 11 frequencies in both ears. Multivariate, generalized linear models were used to estimate the associations between PCB concentrations at different ages and DPOAEs, adjusting for potential confounders. Maternal and cord PCB-153 concentrations were not associated with DPOAEs at 45 months. Higher postnatal PCB concentrations at 6-, 16-, and 45-months of age were associated with lower (poorer) DPOAE amplitudes. When all postnatal PCB exposures were considered as an area-under-the-curve metric, an increase in PCB-153 concentration from the 25th to the 75th percentile was associated with a 1.6-dB SPL (sound pressure level) decrease in DPOAE amplitude (95% CI: -2.6, -0.5; p = 0.003). In this study, postnatal rather than maternal or cord PCB concentrations were associated with poorer performance on otoacoustic tests at age 45 months.

Stereoselective bioaccumulation of chiral PCB 91 in earthworm and its metabolomic and lipidomic responses.

Science.gov (United States)

He, Zeying; Wang, Yuehua; Zhang, Yanwei; Cheng, Haiyan; Liu, Xiaowei

2018-07-01

Stereoselective bioaccumulation, elimination, metabolomic and lipidomic responses of earthworm Eisenia fetida exposed to chiral polychlorinated biphenyl (PCB) 91 in an earthworm-soil system were investigated. Preferential bioaccumulation of (-)-PCB 91 and elimination of (+)-PCB 91 were observed following 50 and 500 μg/kg dwt exposures. Enantiomer fraction (EF) values decreased over time during the uptake and elimination periods. Metabolomics and lipidomics techniques based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) revealed significant changes in 108 metabolites after earthworms exposure to (+)-, (-)-, and (±)-PCB 91, compared to control groups. Forty two of these metabolites were identified as amino acids, nucleosides, fatty acids, dicarboxylic acids, vitamins or others. Lysophospholipids including six lysophosphatidylcholines (LPC), six lysophosphatidylethanolamine (LPE), eight lysophosphatidylinositol (LPI) and five lysophosphatidylserine (LPS) were also differentially expressed between exposure and control groups. Alterations in the levels of metabolites and lipids indicated stereoselective effects of chiral PCB 91 on earthworm amino acid, energy, and nucleotide metabolism, neurodevelopment and gene expression. Overall, the effects of (+)-PCB 91 were more pronounced than that of (-)- and (±)-PCB 91. Copyright © 2018 Elsevier Ltd. All rights reserved.

Males exceed females in PCB concentrations of cisco (Coregonus artedi) from Lake Superior

Science.gov (United States)

Madenjian, Charles P.; Yule, Daniel L.; Chernyak, Sergei M.; Begnoche, Linda J.; Berglund, Eric K.; Isaac, Edmund J.

2014-01-01

We determined whole-fish polychlorinated biphenyl (PCB) concentrations of 25 male and 25 female age-7 ciscoes (Coregonus artedi) captured from a spawning aggregation in Thunder Bay, Lake Superior, during November 2010. We also determined PCB concentrations in the ovaries and somatic tissue of five additional female ciscoes (ages 5–22). All 55 of these ciscoes were in ripe or nearly ripe condition. Bioenergetics modeling was used to determine the contribution of the growth dilution effect toward a difference in PCB concentrations between the sexes, as females grew substantially faster than males. Results showed that the PCB concentration of males (mean = 141 ng/g) was 43% greater than that of females (mean = 98 ng/g), and this difference was highly significant (P ovaries and the somatic tissue of the five females were 135 and 100 ng/g, respectively. Based on these PCB determinations for the ovaries and somatic tissue, we concluded that release of eggs by females at previous spawnings was not a contributing factor to the observed difference in PCB concentrations between the sexes. Bioenergetics modeling results indicated that the growth dilution effect could explain males being higher than females in PCB concentration by only 3–7%. We concluded that the higher PCB concentration in males was most likely due to higher rate of energy expenditure, originating from greater activity and a higher resting metabolic rate. Mean PCB concentration in the cisco eggs was well below the U. S. Food and Drug Administration and Ontario Ministry of Environment guidelines of 2000 and 844 ng/g, respectively, and this finding may have implications for the cisco roe fishery currently operating in Lake Superior.

Complete PCB design using OrCAD capture and PCB editor

CERN Document Server

Mitzner, Kraig

2009-01-01

This book provides instruction on how to use the OrCAD design suite to design and manufacture printed circuit boards. The primary goal is to show the reader how to design a PCB using OrCAD Capture and OrCAD Editor. Capture is used to build the schematic diagram of the circuit, and Editor is used to design the circuit board so that it can be manufactured. The book is written for both students and practicing engineers who need in-depth instruction on how to use the software, and who need background knowledge of the PCB design process. KEY FEATURES:* Beginning to end cove

The mechanism for enhanced oxidation degradation of dioxin-like PCBs (PCB-77) in the atmosphere by the solvation effect.

Science.gov (United States)

Xin, Mei-Ling; Yang, Jia-Wen; Li, Yu

2017-07-11

The reaction pathways of PCB-77 in the atmosphere with ·OH, O 2 , NO x , and 1 O 2 were inferred based on density functional theory calculations with the 6-31G* basis set. The structures the reactants, transition states, intermediates, and products were optimized. The energy barriers and reaction heats were obtained to determine the energetically favorable reaction pathways. To study the solvation effect, the energy barriers and reaction rates for PCB-77 with different polar and nonpolar solvents (cyclohexane, benzene, carbon tetrachloride, chloroform, acetone, dichloromethane, ethanol, methanol, acetonitrile, dimethylsulfoxide, and water) were calculated. The results showed that ·OH preferentially added to the C5 atom of PCB-77, which has no Cl atom substituent, to generate the intermediate IM5. This intermediate subsequently reacted with O 2 via pathway A to generate IM5a, with an energy barrier of 7.27 kcal/mol and total reaction rate of 8.45 × 10 -8  cm 3 /molecule s. Pathway B involved direct dehydrogenation of IM5 to produce the OH-PCBs intermediate IM5b, with an energy barrier of 28.49 kcal/mol and total reaction rate of 1.15 × 10 -5  cm 3 /molecule s. The most likely degradation pathway of PCB-77 in the atmosphere is pathway A to produce IM5a. The solvation effect results showed that cyclohexane, carbon tetrachloride, and benzene could reduce the reaction energy barrier of pathway A. Among these solvents, the solvation effect of benzene was the largest, and could reduce the total reaction energy barrier by 25%. Cyclohexane, carbon tetrachloride, benzene, dichloromethane, acetone, and ethanol could increase the total reaction rate of pathway A. The increase in the reaction rate of pathway A with benzene was 8%. The effect of solvents on oxidative degradation of PCB-77 in the atmosphere is important. Graphical abstract The reaction pathways of PCB-77 in the atmosphere with •OH, O2, NOx, and 1O2 were inferred based on density functional theory

Effect of seafood mediated PCB exposure on desaturase activity and PUFA profile in Faroese septuagenarians.

Science.gov (United States)

Tøttenborg, Sandra Søgaard; Choi, Anna L; Bjerve, Kristian S; Weihe, Pal; Grandjean, Philippe

2015-07-01

Polychlorinated biphenyl (PCB) exposure may affect serum concentrations of polyunsaturated fatty acids (PUFAs) by inhibiting desaturases ∆5 and ∆6 that drive their synthesis from precursor fatty acids. Such changes in the composition of fatty acids may affect cardiovascular disease risk, which is thought to increase at elevated PCB exposures. This population-based cross-sectional study examined 712 Faroese men and women aged 70-74 years. The serum phospholipid fraction of fasting blood samples was used to determine the PUFA profile, including linoleic acid, dihomo-γ-linolenic acid, arachidonic acid, eicosatrienoic acid, and other relevant fatty acids. Ratios between precursor and metabolite fatty acids were used as proxies for ∆5 and ∆6 desaturase activity. Tertiles of serum-PCB concentrations were used in multiple regression analyses to determine the association between the exposure and desaturase activity. In multiple regression models, PCB exposure was inversely related to the estimated Δ6 desaturase activity resulting in accumulation of precursor fatty acids and decrease in the corresponding product PUFAs. A positive association between PCB and Δ5 desaturation was also found. A relative increase in EA was also observed, though only in the third tertile of PCB exposure. Non-linear relationships between the exposure and the desaturase activity were not found. Consuming fish and seafood may not be translated into beneficial fatty acid profiles if the diet simultaneously causes exposure to PCBs. Although the desaturase estimates were likely influenced by dietary intakes of product PUFAs, the association between PCB exposure and ∆6 desaturase activity is plausible and may affect cardiovascular disease risk. Copyright © 2015 Elsevier Inc. All rights reserved.

Treatability of PCB-contaminated soils with quicklime (CaO)

International Nuclear Information System (INIS)

Mauro, D.; Taylor, B.B.

1992-12-01

The possibility that quicklime (calcium oxide, CaO) can destroy PCBs has received much attention over the past year. Observations at an EPA remediation site, where lime-containing kiln dusts were used for interim stabilization of PCB-containing wastes prompted the EPA to sponsor a small research project to investigate quicklime-PCB interactions. That study reported decreases in PCB content in synthetic, PCB-spiked soil following the application of quicklime and heat. META Environmental, Inc., as a contractor to EPRI, recently completed research designed to evaluate the effectiveness of quicklime for treating PCBs in soil and sand matrices under several reaction conditions, and to examine the underlying dechlorination chemistry involved, if any. Experiments were run with PCB-spiked sand and with actual PCB-contaminated soil. A variety of experimental conditions were employed including tests in open and closed containers, at ambient and elevated temperatures, and over a range of one hour to four days. Granular quicklime, fly ash, and kiln dust were all tested for reaction with PCBs. Early experiments showed that a mixture of sand/quicklime/water at 1:3:1.5 by weight, placed in an insulated container reached a maximum temperature of 216 degree C. Treatability experiments were subsequently run under controlled heat at room temperature, at 80 degree C, and at 200 degree C (following the initial temperature increase which occurs when water is added to quicklime). Little or no loss of PCBs was observed in open or closed containers at ambient or at 800 degree C over any period of time studied. A significant decrease of PCBs levels was observed only in the high temperature experiments (above 200 degree C), however the fate of the PCBs in those experiments was not determined. The conditions and the results of the PCB treatment tests are presented in this report, as well as recommendations for further studies

Modulation of 17{beta}-estradiol-induced responses in fish by cytochrome P4501A1 inducing compounds

Energy Technology Data Exchange (ETDEWEB)

Anderson, M.J.; Hinton, D.E. [Univ. of California, Davis, CA (United States)

1995-12-31

Some compounds which induce cytochrome P4501A1 (CYP1A1) are antiestrogenic in mammalian bioassay, and this effect is linked to aryl hydrocarbon (Ah) receptor. Liver of fish synthesizes estrogen-inducible egg yolk precursor protein vitellogenin (Vg) which is critical for oocyte maturation and ovarian development. To determine if Ah receptor-linked endocrine modulation could occur in fish liver, primary cultures of juvenile rainbow trout (Oncorhynchus mykiss) liver cells were co-administered 17{beta}-estradiol and CYP1A1 inducing compounds. Vitellogenin and albumin, estimated by ELISA measurement of concentration in the media 48 hrs after treatment, formed the basis for the test. Cellular CYP1A1 protein content and catalytic activity was estimated by ELISA and ethoxyresorufin-O-deethylase (EROD) activity assays respectively. Equivalent viability (mitochondrial dehydrogenase activity) and secretary functional capacity (albumin synthesis) were estimated and correlated with other results. In descending order, 2,3,4,7,8 pentachlorodibenzofuran (10{sup {minus}12} to 10{sup {minus}8} M) > 2,3,7,8 tetrachlorodibenzo-p-dioxin {approx_equal} 2,3,7,8 tetrachlorodibenzofuran (10{sup {minus}11} to 10{sup {minus}8} M) > {beta}-naphthoflavone (10{sup {minus}7} to 10{sup {minus}6} M) inhibited Vg synthesis in 17{beta}-estradiol treated liver cells. Potency of inhibition directly related to strength as an inducer of CYP1A1 protein. At 10-8 M, PCB congeners 77, 126, and 156 did not inhibit Vg synthesis and induced no or only moderate CYP1A1 protein. At 10-8 M, PCB congener 114, a weak CYP1A1 inducer, potentiated Vg synthesis relative to cells treated with 17{beta}-estradiol alone. This study increases their understanding of the consequences of hepatic CYP1A1 induction, forewarns of reproductive impairment of sexually maturing fishes exposed to CYP1A1 inducing compounds and argues for further, more detailed in vivo investigation.

Phenomenological and Spectroscopic Analysis on the Effects of Sediment Ageing and Organic Carbon on the Fate of a PCB Congener Spiked to Sediment

Science.gov (United States)

This study assesses the full cycle transport and fate of a polychlorinated biphenyl (PCB) congener spiked to sediment to empirically and spectroscopically investigate the effects of sediment ageing and organic carbon on the adsorption, desorption, and reaction of the PCB. Caesar ...

Transcriptomic assessment of resistance to effects of an aryl hydrocarbon receptor (AHR agonist in embryos of Atlantic killifish (Fundulus heteroclitus from a marine Superfund site

Directory of Open Access Journals (Sweden)

Franks Diana G

2011-05-01

Full Text Available Abstract Background Populations of Atlantic killifish (Fundulus heteroclitus have evolved resistance to the embryotoxic effects of polychlorinated biphenyls (PCBs and other halogenated and nonhalogenated aromatic hydrocarbons that act through an aryl hydrocarbon receptor (AHR-dependent signaling pathway. The resistance is accompanied by reduced sensitivity to induction of cytochrome P450 1A (CYP1A, a widely used biomarker of aromatic hydrocarbon exposure and effect, but whether the reduced sensitivity is specific to CYP1A or reflects a genome-wide reduction in responsiveness to all AHR-mediated changes in gene expression is unknown. We compared gene expression profiles and the response to 3,3',4,4',5-pentachlorobiphenyl (PCB-126 exposure in embryos (5 and 10 dpf and larvae (15 dpf from F. heteroclitus populations inhabiting the New Bedford Harbor, Massachusetts (NBH Superfund site (PCB-resistant and a reference site, Scorton Creek, Massachusetts (SC; PCB-sensitive. Results Analysis using a 7,000-gene cDNA array revealed striking differences in responsiveness to PCB-126 between the populations; the differences occur at all three stages examined. There was a sizeable set of PCB-responsive genes in the sensitive SC population, a much smaller set of PCB-responsive genes in NBH fish, and few similarities in PCB-responsive genes between the two populations. Most of the array results were confirmed, and additional PCB-regulated genes identified, by RNA-Seq (deep pyrosequencing. Conclusions The results suggest that NBH fish possess a gene regulatory defect that is not specific to one target gene such as CYP1A but rather lies in a regulatory pathway that controls the transcriptional response of multiple genes to PCB exposure. The results are consistent with genome-wide disruption of AHR-dependent signaling in NBH fish.

Males exceed females in PCB concentrations of cisco (Coregonus artedi) from Lake Superior.

Science.gov (United States)

Madenjian, Charles P; Yule, Daniel L; Chernyak, Sergei M; Begnoche, Linda J; Berglund, Eric K; Isaac, Edmund J

2014-09-15

We determined whole-fish polychlorinated biphenyl (PCB) concentrations of 25 male and 25 female age-7 ciscoes (Coregonus artedi) captured from a spawning aggregation in Thunder Bay, Lake Superior, during November 2010. We also determined PCB concentrations in the ovaries and somatic tissue of five additional female ciscoes (ages 5-22). All 55 of these ciscoes were in ripe or nearly ripe condition. Bioenergetics modeling was used to determine the contribution of the growth dilution effect toward a difference in PCB concentrations between the sexes, as females grew substantially faster than males. Results showed that the PCB concentration of males (mean = 141 ng/g) was 43% greater than that of females (mean = 98 ng/g), and this difference was highly significant (PPCB concentrations in the ovaries and the somatic tissue of the five females were 135 and 100 ng/g, respectively. Based on these PCB determinations for the ovaries and somatic tissue, we concluded that release of eggs by females at previous spawnings was not a contributing factor to the observed difference in PCB concentrations between the sexes. Bioenergetics modeling results indicated that the growth dilution effect could explain males being higher than females in PCB concentration by only 3-7%. We concluded that the higher PCB concentration in males was most likely due to higher rate of energy expenditure, originating from greater activity and a higher resting metabolic rate. Mean PCB concentration in the cisco eggs was well below the U. S. Food and Drug Administration and Ontario Ministry of Environment guidelines of 2000 and 844 ng/g, respectively, and this finding may have implications for the cisco roe fishery currently operating in Lake Superior. Published by Elsevier B.V.

PCB i bygninger - afhjælpning, renovering og nedrivning

DEFF Research Database (Denmark)

Andersen, Helle Vibeke

SBi-anvisning 268 beskriver, hvordan PCB-forurening af indeluften afhjælpes, og hvordan PCB håndteres, når man renoverer eller nedriver bygninger med PCB. Uanset om der er tale om afhjælpning, renovering eller nedrivning, kan arbejdet generere PCB-holdigt affald. Anvisningen forklarer derfor......, hvordan affaldet skal håndteres, og hvordan man beskytter mennesker og miljø under arbejdet. Anvisningen er baseret på byggebranchens erfaringer og den aktuelle forskningsbaserede viden om PCB i bygninger. SBi-anvisning 268 afløser den snart fire år gamle SBi-anvisning 242 om renovering af bygninger med...... PCB, som ikke behandlede spørgsmålet om affaldshåndtering....

Reference standards for quantitative trace analysis of PCB's by GC. Technical PCB formulations for the calibration of ECD and MSD responses

Energy Technology Data Exchange (ETDEWEB)

Krupcik, J. (Slovak Technical Univ., Department of Analytical Chemistry, Bratislava (Slovakia)); Kocan, A. (Institute of Preventive Medicine, Bratislava (Slovakia)); Petrik, J. (Institute of Preventive Medicine, Bratislava (Slovakia)); Leclercq, P.A. (Eindhoven University of Technology, Dept. of Chemical Engineering, Lab. of Instrumental Analysis (Netherlands)); Ballschmiter, K. (University of Ulm, Dept. of Analytical and Environmental Chemistry (Germany))

1993-04-01

The composition of any technical PCB formulation can be determined directly by analyzing the PCB sample by gas chromatography with a flame ionization detector (GC-FID), provided the relative molecular masses of the components are known. The response of electron capture and selected-ion monitoring, mass-spectra detectors can then be calibrated for individual PCB congeners by correlation of the chromatographic patterns with those of concentrated PCB samples obtained by GC-FID. This procedure, which uses a given technical PCB formulation as a secondary reference standard mixture, is to be preferred over existing calibration methods, when results with [+-]10% errors are acceptable because commercial PCB formulations cover the whole range of chlorination products. (orig.)

Effect of seafood mediated PCB exposure on desaturase activity and PUFA profile in Faroese septuagenarians

DEFF Research Database (Denmark)

Tøttenborg, Sandra Søgaard; Choi, Anna L; Bjerve, Kristian S

2015-01-01

and desaturase activity. In multiple regression models, PCB exposure was inversely related to the estimated Δ6 desaturase activity resulting in accumulation of precursor fatty acids and decrease in the corresponding product PUFAs. A positive association between PCB and Δ5 desaturation was also found. A relative...... increase in EA was also observed, though only in the third tertile of PCB exposure. Non-linear relationships between the exposure and the desaturase activity were not found. Consuming fish and seafood may not be translated into beneficial fatty acid profiles if the diet simultaneously causes exposure...

In situ application of activated carbon and biochar to PCB-contaminated soil and the effects of mixing regime

International Nuclear Information System (INIS)

Denyes, Mackenzie J.; Rutter, Allison; Zeeb, Barbara A.

2013-01-01

The in situ use of carbon amendments such as activated carbon (AC) and biochar to minimize the bioavailability of organic contaminants is gaining in popularity. In the first in situ experiment conducted at a Canadian PCB-contaminated Brownfield site, GAC and two types of biochar were statistically equal at reducing PCB uptake into plants. PCB concentrations in Cucurbita pepo root tissue were reduced by 74%, 72% and 64%, with the addition of 2.8% GAC, Burt's biochar and BlueLeaf biochar, respectively. A complementary greenhouse study which included a bioaccumulation study of Eisenia fetida (earthworm), found mechanically mixing carbon amendments with PCB-contaminated soil (i.e. 24 h at 30 rpm) resulted in shoot, root and worm PCB concentrations 66%, 59% and 39% lower than in the manually mixed treatments (i.e. with a spade and bucket). Therefore, studies which mechanically mix carbon amendments with contaminated soil may over-estimate the short-term potential to reduce PCB bioavailability. Highlights: •Biochar and GAC reduced PCB uptake into plants and earthworms. •Biochar offered additional benefits, including increased plant and earthworm biomass. •BSAF reductions are greater when amendments are mechanically vs. manually mixed. •Mechanically mixing carbon amendments may over-estimate their remediation potential. -- In situ AC and biochar soil amendments perform equally well at reducing PCB uptake, however, laboratory-based mixing methods may exaggerate the sorptive capacities of both amendments

GSK126 (EZH2 inhibitor) interferes with ultraviolet A radiation-induced photoaging of human skin fibroblast cells

Science.gov (United States)

Qin, Haiyan; Zhang, Guang; Zhang, Lianbo

2018-01-01

Polycomb group genes (PcG) encode chromatin modification proteins that are involved in the epigenetic regulation of cell differentiation, proliferation and the aging processes. The key subunit of the PcG complex, enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), has a central role in a variety of mechanisms, such as the formation of chromatin structure, gene expression regulation and DNA damage. In the present study, ultraviolet A (UVA) was used to radiate human dermal fibroblasts in order to construct a photo-aged cell model. Subsequently, the cell viability assay, Hoechst staining, apoptosis detection using flow cytometry, senescence-associated β-galactosidase (SA-β-gal) staining and erythrocyte exclusion experiments were performed. GSK126, a histone methylation enzyme inhibitor of EZH2, was used as an experimental factor. Results suggested that GSK126 downregulated the mRNA expression levels of EZH2 and upregulated the mRNA expression levels of BMI-1. Notably, GSK126 affected the transcription of various photoaging-related genes and thus protected against photoaging induced by UVA radiation. PMID:29545866

Insight in the PCB-degrading functional community in long-term contaminated soil under bioremediation

Energy Technology Data Exchange (ETDEWEB)

Petric, Ines; Hrsak, Dubravka; Udikovic-Kolic, Nikolina [Ruder Boskovic Inst., Division for Marine and Environmental Research, Zagreb (Croatia); Fingler, Sanja [Inst. for Medical Research and Occupational Health, Zagreb (Croatia); Bru, David; Martin-Laurent, Fabrice [INRA, Univ. der Bourgogne, Soil and Environmental Microbiology, Dijon (France)

2011-02-15

A small-scale bioremediation assay was developed in order to get insight into the functioning of a polychlorinated biphenyl (PCB) degrading community during the time course of bioremediation treatment of a contaminated soil. The study was conducted with the aim to better understand the key mechanisms involved in PCB-removal from soils. Materials and methods Two bioremediation strategies were applied in the assay: (a) biostimulation (addition of carvone as inducer of biphenyl pathway, soya lecithin for improving PCB bioavailability, and xylose as supplemental carbon source) and (b) bioaugmentation with selected seed cultures TSZ7 or Rhodococcus sp. Z6 originating from the transformer station soil and showing substantial PCB-degrading activity. Functional PCB-degrading community was investigated by using molecular-based approaches (sequencing, qPCR) targeting bphA and bphC genes, coding key enzymes of the upper biphenyl pathway, in soil DNA extracts. In addition, kinetics of PCBs removal during the bioremediation treatment was determined using gas chromatography mass spectrometry analyses. Results and discussion bphA-based phylogeny revealed that bioremediation affected the structure of the PCB-degrading community in soils, with Rhodococcus-like bacterial populations developing as dominant members. Tracking of this population further indicated that applied bioremediation treatments led to its enrichment within the PCB-degrading community. The abundance of the PCB-degrading community, estimated by quantifying the copy number of bphA and bphC genes, revealed that it represented up to 0.3% of the total bacterial community. All bioremediation treatments were shown to enhance PCB reduction in soils, with approximately 40% of total PCBs being removed during a 1-year period. The faster PCB reduction achieved in bioaugmented soils suggested an important role of the seed cultures in bioremediation processes. Conclusions The PCBs degrading community was modified in response to

Relationships between Atmospheric Transport Regimes and PCB Concentrations in the Air at Zeppelin, Spitsbergen.

Science.gov (United States)

Ubl, Sandy; Scheringer, Martin; Hungerbühler, Konrad

2017-09-05

Polychlorinated biphenyls (PCBs) are persistent hazardous chemicals that are still detected in the atmosphere and other environmental media, although their production has been banned for several decades. At the long-term monitoring site, Zeppelin at Spitsbergen, different PCB congeners have been continuously measured for more than a decade. However, it is not clear what factors determine the seasonal and interannual variability of different (lighter versus heavier) PCB congeners. To investigate the influence of atmospheric transport patterns on PCB-28 and PCB-101 concentrations at Zeppelin, we applied the Lagrangian Particle Dispersion Model FLEXPART and calculated "footprints" that indicate the potential source regions of air arriving at Zeppelin. By means of a cluster analysis, we assigned groups of similar footprints to different transport regimes and analyzed the PCB concentrations according to the transport regimes. The concentrations of both PCB congeners are affected by the different transport regimes. For PCB-101, the origin of air masses from the European continent is primarily related to high concentrations; elevated PCB-101 concentrations in winter can be explained by the high frequency of this transport regime in winter, whereas PCB-101 concentrations are low when air is arriving from the oceans. For PCB-28, in contrast, concentrations are high during summer when air is mainly arriving from the oceans but low when air is arriving from the continents. The most likely explanation of this finding is that local emissions of PCB-28 mask the effect of long-range transport and determine the concentrations measured at Zeppelin.

Polychlorinated biphenyls exposure-induced insulin resistance is mediated by lipid droplet enlargement through Fsp27.

Science.gov (United States)

Kim, Hye Young; Kwon, Woo Young; Kim, Yeon A; Oh, Yoo Jin; Yoo, Seung Hee; Lee, Mi Hwa; Bae, Ju Yong; Kim, Jong-Min; Yoo, Young Hyun

2017-06-01

Although epidemiological and experimental studies demonstrated that polychlorinated biphenyls (PCBs) lead to insulin resistance, the mechanism underlying PCBs-induced insulin resistance has remained unsolved. In this study, we examined in vitro and in vivo effects of PCB-118 (dioxin-like PCB) and PCB-138 (non-dioxin-like PCB) on adipocyte differentiation, lipid droplet growth, and insulin action. 3T3-L1 adipocytes were incubated with PCB-118 or PCB-138 during adipocyte differentiation. For in vivo studies, C57BL/6 mice were administered PCB-118 or PCB-138 (37.5 mg/kg) by intraperitoneal injection and we examined adiposity and whole-body insulin action. PCB-118 and PCB-138 significantly promoted adipocyte differentiation and increased the lipid droplet (LD) size in 3T3-L1 adipocytes. In mice, both PCBs increased adipose mass and adipocyte size. Furthermore, both PCBs induced insulin resistance in vitro and in vivo. Expression of fat-specific protein 27 (Fsp27), which is localized to LD contact sites, was increased in PCB-treated 3T3-L1 adipocytes and mice. Depletion of Fsp27 by siRNA resulted in the inhibition of LD enlargement and attenuation of insulin resistance in PCB-treated 3T3-L1 adipocytes. An anti-diabetic drug, metformin, attenuated insulin resistance in PCB-treated 3T3-L1 adipocytes through the reduced expression of Fsp27 protein and LD size. This study suggests that PCB exposure-induced insulin resistance is mediated by LD enlargement through Fsp27.

Associations between plasma concentrations of PCB 28 and possible indoor exposure sources in Danish school children and mothers.

Science.gov (United States)

Egsmose, Emilie Lund; Bräuner, Elvira Vaclavik; Frederiksen, Marie; Mørck, Thit Aarøe; Siersma, Volkert Dirk; Hansen, Pernille Winton; Nielsen, Flemming; Grandjean, Philippe; Knudsen, Lisbeth E

2016-02-01

Polychlorinated biphenyls (PCBs) are ubiquitously present in the environment and are suspected of carcinogenic, neurotoxic and immunotoxic effects. Significantly higher plasma concentrations of the congener PCB 28 occur in children compared to adults. Exposure in schools may contribute to this difference. To determine whether increased blood plasma concentrations of PCB 28 in Danish school children and mothers are associated with living in homes or attending schools constructed in the PCB period (1959-1977). PCB 28 was analyzed in plasma samples from 116 children aged 6-11years and 143 mothers living in an urban and a rural area in Denmark and participating in the European pilot project DEMOCOPHES (Demonstration of a study to COordinate and Perform Human Biomonitoring on a European Scale). In Denmark, PCBs were used in construction in the period 1950-1977, and year of construction or renovation of the homes and schools was used as a proxy for indoor PCB exposure. Linear regression models were used to assess the association between potential PCB exposure from building materials and lipid adjusted concentrations of PCB 28 in plasma, with and without adjustment for potential confounders. Among the 116 children and 143 mothers, we were able to specify home construction period in all but 4 children and 5 mothers leaving 111 children and 138 mothers for our analyses. The median lipid adjusted plasma PCB 28 concentration was 3 (range: 1-28) ng/g lipid in the children and 2 (range: 1-8) ng/g lipid in the mothers. Children living in homes built in the PCB period had significantly higher lipid adjusted plasma PCB 28 concentrations compared to children living in homes built before or after the PCB period. Following adjustment for covariates, PCB 28 concentrations in children were 40 (95% CI: 13; 68) percent higher than concentrations of children living in homes constructed at other times. Furthermore, children attending schools built or substantially refurbished in the PCB

21 CFR 109.30 - Tolerances for polychlorinated biphenyls (PCB's).

Science.gov (United States)

2010-04-01

... Tolerances for polychlorinated biphenyls (PCB's). (a) Polychlorinated biphenyls (PCB's) are toxic, industrial chemicals. Because of their widespread, uncontrolled industrial applications, PCB's have become a persistent... unavoidable environmental or industrial contaminants are established for a sufficient period of time following...

40 CFR 761.63 - PCB household waste storage and disposal.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false PCB household waste storage and..., AND USE PROHIBITIONS Storage and Disposal § 761.63 PCB household waste storage and disposal. PCB... to manage municipal or industrial solid waste, or in a facility with an approval to dispose of PCB...

3,3′,4,4′,5-Pentachlorobiphenyl Inhibits Drug Efflux Through P-Glycoprotein in KB-3 Cells Expressing Mutant Human P-Glycoprotein

Directory of Open Access Journals (Sweden)

Hiroshi Fujise

2004-01-01

Full Text Available The effects on the drug efflux of 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126, the most toxic of all coplanar polychlorinated biphenyls (Co-PCBs, were examined in KB-3 cells expressing human wild-type and mutant P-glycoprotein in which the 61st amino acid was substituted for serine or phenylalanine (KB3-Phe61. In the cells expressing P-glycoproteins, accumulations of vinblastine and colchicine decreased form 85% to 92% and from 62% to 91%, respectively, and the drug tolerances for these chemicals were increased. In KB3-Phe61, the decreases in drug accumulation were inhibited by adding PCB-126 in a way similar to that with cyclosporine A: by adding 1 μM PCB-126, the accumulations of vinblastine and colchicine increased up to 3.3- and 2.3-fold, respectively. It is suggested that PCB-126 decreased the drug efflux by inhibiting the P-glycoprotein in KB3-Phe61. Since there were various P-glycoproteins and many congeners of Co-PCBs, this inhibition has to be considered a new cause of the toxic effects of Co-PCBs.

Kartlegging av PCB i sedimenter fra Indre Sørfjord

OpenAIRE

Skei, J.; Klungsøyr, J.

1990-01-01

Som følge av forhøyede nivåer av PCB i fiskelever innerst i Sørfjorden er det gjennomført en sedimentundersøkelse for om mulig å finne kilden til PCB. Det ble ikke registrert høye nivåer av PCB i sedimentene. Høyeste konsentrasjoner ble målt i munningen av Eitrheimsvågen. Analyser av trafooljer brukt i Tyssedalsområdet viste spor av PCB. Statens forurensningstilsyn (SFT)

22 CFR 126.12 - Continuation in force.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Continuation in force. 126.12 Section 126.12... PROVISIONS § 126.12 Continuation in force. All determinations, authorizations, licenses, approvals of... previous provisions of this subchapter, continue in full force and effect until or unless modified, revoked...

Remediation of PCB [polychlorinated biphenyl] -contaminated soils from scrapyards

International Nuclear Information System (INIS)

MacKnight, S.

1991-01-01

Much of the recent attention on contamination of the environment by polychlorinated biphenyls (PCB) has focused on liquid PCB spills from electrical equipment. A new, and possibly more serious, source of PCB contamination is the scrap yard, typically located in or near major urban centers, where the local scrap dealer would purchase used transformers or other PCB-containing electrical equipment, recover copper and other metals, and dump the PCB-containing oils on the ground. With the rising value of urban and suburban lands, these scrap yards may be slated for redevelopment, making the cleanup of contaminated soils necessary. The heterogeneous distribution of scrap yard contaminants requires a very detailed site assessment, and the heterogeneous mixture of typical scrap yard contaminants (not only PCB) cannot be treated in a simple fashion. These problems are illustrated for the case of the assessment and cleanup of a scrap yard site in Nova Scotia. A grid block system was used to sample soil at the site, and samples were analyzed for PCB, metals, and hydrocarbons. The most severely contaminated spots were mapped; groundwater patterns were also examined. The remediation process can be divided into 5 phases: physical separation of uncontaminated material; three stages of separation of materials into those having single, several-but-similar, and multicomponent mixed contaminations; and selection of appropriate process technologies. Since there is currently no approved PCB destruction facility in Atlantic Canada, excavated soils containing PCB are stored securely on the site to await approval for some type of incineration process

Sampling methodology and PCB analysis

International Nuclear Information System (INIS)

Dominelli, N.

1995-01-01

As a class of compounds PCBs are extremely stable and resist chemical and biological decomposition. Diluted solutions exposed to a range of environmental conditions will undergo some preferential degradation and the resulting mixture may differ considerably from the original PCB used as insulating fluid in electrical equipment. The structure of mixtures of PCBs (synthetic compounds prepared by direct chlorination of biphenyl with chlorine gas) is extremely complex and presents a formidable analytical problem, further complicated by the presence of PCBs as contaminants in oils to soils to water. This paper provides some guidance into sampling and analytical procedures; it also points out various potential problems encountered during these processes. The guidelines provided deal with sample collection, storage and handling, sample stability, laboratory analysis (usually gas chromatography), determination of PCB concentration, calculation of total PCB content, and quality assurance. 1 fig

Automatic extraction of via in the CT image of PCB

Science.gov (United States)

Liu, Xifeng; Hu, Yuwei

2018-04-01

In modern industry, the nondestructive testing of printed circuit board (PCB) can prevent effectively the system failure and is becoming more and more important. In order to detect the via in the PCB base on the CT image automatically accurately and reliably, a novel algorithm for via extraction based on weighting stack combining the morphologic character of via is designed. Every slice data in the vertical direction of the PCB is superimposed to enhanced vias target. The OTSU algorithm is used to segment the slice image. OTSU algorithm of thresholding gray level images is efficient for separating an image into two classes where two types of fairly distinct classes exist in the image. Randomized Hough Transform was used to locate the region of via in the segmented binary image. Then the 3D reconstruction of via based on sequence slice images was done by volume rendering. The accuracy of via positioning and detecting from a CT images of PCB was demonstrated by proposed algorithm. It was found that the method is good in veracity and stability for detecting of via in three dimensional.

EFFECTS OF PCB 84 ENANTIOMERS ON 3H-PHORBOL ESTER BINDING IN RAT CEREBELLAR GRANULE CELLS AND 45CA2+-UPTAKE IN RAT CEREBELLUM.

Science.gov (United States)

This is the first report showing the effects of 2,2,3,3,6-pentachlorobiphenyl (PCB 84) enantiomers on key neurochemical events involved in the development and function of the nervous system. Our previous reports provided evidence that ortho-substituted PCBs like PCB 84 have pot...

PCB 136 Atropselectively Alters Morphometric and Functional Parameters of Neuronal Connectivity in Cultured Rat Hippocampal Neurons via Ryanodine Receptor-Dependent Mechanisms

Science.gov (United States)

Yang, Dongren; Kania-Korwel, Izabela; Ghogha, Atefeh; Chen, Hao; Stamou, Marianna; Bose, Diptiman D.; Pessah, Isaac N.; Lehmler, Hans-Joachim; Lein, Pamela J.

2014-01-01

We recently demonstrated that polychlorinated biphenyl (PCB) congeners with multiple ortho chlorine substitutions sensitize ryanodine receptors (RyRs), and this activity promotes Ca2+-dependent dendritic growth in cultured neurons. Many ortho-substituted congeners display axial chirality, and we previously reported that the chiral congener PCB 136 (2,2′,3,3′,6,6′-hexachlorobiphenyl) atropselectively sensitizes RyRs. Here, we test the hypothesis that PCB 136 atropisomers differentially alter dendritic growth and other parameters of neuronal connectivity influenced by RyR activity. (−)-PCB 136, which potently sensitizes RyRs, enhances dendritic growth in primary cultures of rat hippocampal neurons, whereas (+)-PCB 136, which lacks RyR activity, has no effect on dendritic growth. The dendrite-promoting activity of (−)-PCB 136 is observed at concentrations ranging from 0.1 to 100nM and is blocked by pharmacologic RyR antagonism. Neither atropisomer alters axonal growth or cell viability. Quantification of PCB 136 atropisomers in hippocampal cultures indicates that atropselective effects on dendritic growth are not due to differential partitioning of atropisomers into cultured cells. Imaging of hippocampal neurons loaded with Ca2+-sensitive dye demonstrates that (−)-PCB 136 but not (+)-PCB 136 increases the frequency of spontaneous Ca2+ oscillations. Similarly, (−)-PCB 136 but not (+)-PCB 136 increases the activity of hippocampal neurons plated on microelectrode arrays. These data support the hypothesis that atropselective effects on RyR activity translate into atropselective effects of PCB 136 atropisomers on neuronal connectivity, and suggest that the variable atropisomeric enrichment of chiral PCBs observed in the human population may be a significant determinant of individual susceptibility for adverse neurodevelopmental outcomes following PCB exposure. PMID:24385416

Plant exudates promote PCB degradation by a rhodococcal rhizobacteria

Energy Technology Data Exchange (ETDEWEB)

Toussaint, Jean-Patrick; Pham, Thi Thanh My; Barriault, Diane; Sylvestre, Michel [Instiut National de la Recherche Scientifique INRS, Laval, QC (Canada). Inst. Armand-Frappier

2012-09-15

Rhodococcus erythropolis U23A is a polychlorinated biphenyl (PCB)-degrading bacterium isolated from the rhizosphere of plants grown on a PCB-contaminated soil. Strain U23A bphA exhibited 99% identity with bphA1 of Rhodococcus globerulus P6. We grew Arabidopsis thaliana in a hydroponic axenic system, collected, and concentrated the plant secondary metabolite-containing root exudates. Strain U23A exhibited a chemotactic response toward these root exudates. In a root colonizing assay, the number of cells of strain U23A associated to the plant roots (5.7 x 105 CFU g{sup -1}) was greater than the number remaining in the surrounding sand (4.5 x 104 CFU g{sup -1}). Furthermore, the exudates could support the growth of strain U23A. In a resting cell suspension assay, cells grown in a minimal medium containing Arabidopsis root exudates as sole growth substrate were able to metabolize 2,3,4'- and 2,3',4-trichlorobiphenyl. However, no significant degradation of any of congeners was observed for control cells grown on Luria-Bertani medium. Although strain U23A was unable to grow on any of the flavonoids identified in root exudates, biphenyl-induced cells metabolized flavanone, one of the major root exudate components. In addition, when used as co-substrate with sodium acetate, flavanone was as efficient as biphenyl to induce the biphenyl catabolic pathway of strain U23A. Together, these data provide supporting evidence that some rhodococci can live in soil in close association with plant roots and that root exudates can support their growth and trigger their PCB-degrading ability. This suggests that, like the flagellated Gram-negative bacteria, non-flagellated rhodococci may also play a key role in the degradation of persistent pollutants. (orig.)

PCB126 induces deformities during pectoral fin development in little skate

Science.gov (United States)

Polychlorinated biphenyls (PCBs) are ubiquitous legacy chemicals found throughout the environment, which can accumulate in humans, domestic animals, and wildlife. Some PCBs are agonists of the aryl hydrocarbon receptor (AHR) and are potent teratogens in bony fish. Leucoraja erina...

Dose-Response of High-Intensity Training (HIT on Atheroprotective miRNA-126 Levels

Directory of Open Access Journals (Sweden)

Boris Schmitz

2017-05-01

Full Text Available Aim: MicroRNA-126 (miR-126 exerts beneficial effects on vascular integrity, angiogenesis, and atherosclerotic plaque stability. The purpose of this investigation was to analyze the dose-response relationship of high-intensity interval training (HIIT on miR-126-3p and -5p levels.Methods: Sixty-one moderately trained individuals (females = 31 [50.8%]; 22.0 ± 1.84 years were consecutively recruited and allocated into three matched groups using exercise capacity. During a 4-week intervention a HIIT group performed three exercise sessions/week of 4 × 30 s at maximum speed (all-out, a progressive HIIT (proHIIT group performed three exercise sessions/week of 4 × 30 s at maximum speed (all-out with one extra session every week (up to 7 × 30 s and a low-intensity training (LIT control group performed three exercise sessions/week for 25 min <75% of maximum heart rate. Exercise miR-126-3p/-5p plasma levels were determined using capillary blood from earlobes.Results: No exercise-induced increase in miR-126 levels was detected at baseline, neither in the LIT (after 25 min low-intensity running nor the HIIT groups (after 4 min of high-intensity running. After the intervention, the LIT group presented an increase in miR-126-3p, while in the HIIT group, miR-126-3p levels were still reduced (all p < 0.05. An increase for both, miR-126-3p and -5p levels (all p < 0.05, pre- vs. during and post-exercise was detected in the proHIIT group. Between group analysis revealed that miR-126-3p levels after LIT and proHIIT increased by 2.12 ± 2.55 and 1.24 ± 2.46 units (all p < 0.01, respectively, compared to HIIT (−1.05 ± 2.6 units.Conclusions: LIT and proHIIT may be performed to increase individual miR-126 levels. HIIT without progression was less effective in increasing miR-126.

Sensitivity of lake sturgeon (Acipenser fulvescens) early life stages to 2,3,7,8-tetrachlorodibenzo-P-dioxin and 3,3′,4,4′,5-pentachlorobiphenyl

Science.gov (United States)

Tillitt, Donald E.; Buckler, Justin A.; Nicks, Diane; Candrl, James; Claunch, Rachel; Gale, Robert W.; Puglis, Holly J.; Little, Edward E.; Linbo, Tiffany L.; Baker, Mary

2017-01-01

The aquatic food web of the Great Lakes has been contaminated with polychlorinated biphenyls (PCBs) since the mid-20th century. Threats of PCB exposures to long-lived species of fish, such as lake sturgeon (Acipenser fulvescens), have been uncertain because of a lack of information on the relative sensitivity of the species. The objective of the present study was to evaluate the sensitivity of early–life stage lake sturgeon to 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure. Mortality, growth, morphological and tissue pathologies, swimming performance, and activity levels were used as assessment endpoints. Pericardial and yolk sac edema, tubular heart, yolk sac hemorrhaging, and small size were the most commonly observed pathologies in both TCDD and PCB-126 exposures, beginning as early as 4 d postfertilization, with many of these pathologies occurring in a dose-dependent manner. Median lethal doses for PCB-126 and TCDD in lake sturgeon were 5.4 ng/g egg (95% confidence interval, 3.9–7.4 ng/g egg) and 0.61 ng/g egg (0.47–0.82 ng/g egg), respectively. The resulting relative potency factor for PCB-126 (0.11) was greater than the World Health Organization estimate for fish (toxic equivalency factor = 0.005), suggesting that current risk assessments may underestimate PCB toxicity toward lake sturgeon. Swimming activity and endurance were reduced in lake sturgeon survivors from the median lethal doses at 60 d postfertilization. Threshold and median toxicity values indicate that lake sturgeon, like other Acipenser species, are more sensitive to PCB and TCDD than the other genus of sturgeon, Scaphirhynchus, found in North America. Indeed, lake sturgeon populations in the Great Lakes and elsewhere are susceptible to PCB/TCDD-induced developmental toxicity in embryos and reductions in swimming performance.

Effects of Mn addition on microstructure and hardness of Al-12.6Si alloy

Science.gov (United States)

Biswas, Prosanta; Patra, Surajit; Mondal, Manas Kumar

2018-03-01

In this work, eutectic Al-12.6Si alloy with and without manganese (Mn) have been developed through gravity casting route. The effect of Mn concentration (0.0 wt.%, 1 wt%, 2 wt% and 3 wt%) on microstructural morphology and hardness property of the alloy has been investigated. The eutectic Al-12.6 Si alloy exhibits the presence of combine plate, needle and rod-like eutectic silicon phase with very sharp corners and coarser primary silicon particles within the α-Al phase. In addition of 1wt.% of Mn in the eutectic Al-12.6Si alloy, sharp corners of the primary Si and needle-like eutectic Si are became blunt and particles size is reduced. Further, increase in Mn concentration (2.0 wt.%) in the Al-12.6Si alloy, irregular plate shape Al6(Mn,Fe) intermetallics are formed inside the α-Al phase, but the primary and eutectic phase morphology is similar to the eutectic Al-12.6Si alloy. The volume fraction of Al6(Mn,Fe) increases and Al6(Mn,Fe) particles appear as like chain structure in the alloy with 3 wt.% Mn. An increase in Mn concentration in the Al-12.6Si alloys result in the increase in bulk hardness of the alloy as an effects of microstructure modification as well as the presence of harder Al6(Mn,Fe) phase in the developed alloy.

Parametric Design and Rapid Prototyping of Installation Box for Vehicle Terminal PCB

Directory of Open Access Journals (Sweden)

Wang Xingxing

2016-01-01

Full Text Available Installation box for vehicle terminal PCB (Printed Circuit Board was took as research object, which is encountered in the process of project developing. Vehicle terminal PCB in actual development process was set as an example, point cloud data were acquired by three coordinate measuring method; Imageware software was used to reconstruct the vehicle terminal PCB model, basic size parameters of vehicle terminal PCB can be got and then design parameters of installation box for vehicle terminal PCB can be determined. Design of the installation box for vehicle terminal PCB was completed based on Solidworks software, then 3D modeling and 2D drawing of installation box for vehicle terminal PCB was gained. Up Plus 2 rapid prototype machine was used to manufacture installation box for vehicle terminal PCB rapidly based on 3D printing technology, then prototype of installation box for vehicle terminal PCB was obtained. It is of certain engineering significant for single (small amount manufacturing of installation box for general PCB.

Laboratory study of PCB transport from primary sources to settled dust

Science.gov (United States)

Transport of house dust and Arizona Test Dust on polychlorinated biphenyl (PCB)-containing panels and PCB-free panels was investigated in a 30-m3 stainless steel chamber. The PCB-containing panels were aluminum sheets coated with a PCB-spiked, oil-based primer or two-part polysul...

40 CFR 761.269 - Sampling liquid PCB remediation waste.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sampling liquid PCB remediation waste..., AND USE PROHIBITIONS Cleanup Site Characterization Sampling for PCB Remediation Waste in Accordance with § 761.61(a)(2) § 761.269 Sampling liquid PCB remediation waste. (a) If the liquid is single phase...

An overlooked environmental issue? A review of the inadvertent formation of PCB-11 and other PCB congeners and their occurrence in consumer products and in the environment.

Science.gov (United States)

Vorkamp, Katrin

2016-01-15

Polychlorinated biphenyls (PCBs) are banned from production and use in most countries as they are persistent organic pollutants (POPs) of concern for environment and health. Recent research has pointed at a new environment issue resulting from the inadvertent formation of PCBs in certain processes, in particular the pigment production. PCB-11 is a major by-product in these processes, but PCB-28, PCB-52, PCB-77 as well as the nonachlorinated PCBs and PCB-209 have been found in pigments and consumer products as well. In addition to environmental emissions via point sources, in particular related to industrial and municipal wastewater, atmospheric transport seems to be important for the global distribution of PCB-11. Thus, PCB-11 has also been detected in the polar regions. Worldwide air concentrations appear relatively uniform, but maxima have been found in urban and industrialised areas. Data on the uptake and accumulation of PCB-11 in the food chain are still inconclusive: Although food web studies do not show biomagnification, PCB-11 has been detected in humans. The human exposure might originate from the direct contact to consumer products as well as from the omnipresence of PCB-11 in the environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of PCB3 and its hydroxylated metabolites on estradiol secretion, cell viability, and caspase-3 activity in porcine small folicles

Energy Technology Data Exchange (ETDEWEB)

Ptak, A.; Gregoraszczuk, E.L. [Lab. of Reproductive Physiology and Toxicology of Domestic Animals, Inst. of Zoology, Jagiellonian Univ., Krakow (Poland); Ludewig, G.; Lehmler, H.J.; Robertson, L.W. [Dept. of Occupational and Environmental Health, Coll. of Public Health, The Univ. of Iowa, Iowa City, IA (United States)

2004-09-15

In general, highly chlorinated PCBs are slowly metabolized and eliminated. Lower chlorinated PCBs on the other hand are hydroxylated in vitro and in vivo. Surprisingly this does not necessarily mean that these hydroxylated PCBs are rapidly excreted, as recent findings of substantial amounts of hydroxylated PCBs in animal and human blood have shown. Therefore it must be assumed that not only the PCBs themselves, but also their metabolites can participate in the toxic effects of PCBs. Indeed, some hydroxylated metabolites of PCBs (OH-PCBs) have significant estrogenic activity through binding to the estrogen receptors. Surprisingly, PCB54 (2,2',6,6'-tetrachlorobiphenyl) has about 10% of the activity of 4-OH-PCB54 in the MCF-7 focus assay, but does not bind to the estrogen receptor, suggesting the possibility of an additional, yet unknown mechanism of estrogenicity. We found that PCBs and their hydroxylated metabolites cause an increase in estrogen secretion from ovarian follicular cells in vitro, with PCB3 < 4-OHPCB3 < 3, 4-OH-PCB3. The most sensitive follicles were those collected during the early stage of their development. In the present study we used this type of follicles to answer the question whether this observed huge stimulatory action of PCB3 and/or its metabolites on estrogen release into the medium is due to the action on cells viability and cell apoptosis.

Planar PCB Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review

Science.gov (United States)

Eisler, R.; Belisle, A.A.

1996-01-01

Ecological and toxicological aspects of polychlorinated biphenyls (PCBs) in the environment are reviewed with emphasis on biologically active congeners and fish and wildlife. Subtopics include sources and uses, chemical and biochemical properties, concentrations in field collections, lethal and sublethal effects, and recommendations for the protection of sensitive resources. All production of PCBs in the United States ceased in 1977. Of the 1.2 million tons of PCBs manufactured to date, about 65% are still in use in electrical equipment and 31% in various environmental compartments, and 4% were degraded or incinerated. The 209 PCB congeners and their metabolites show wide differences in biological effects. A significant part of the toxicity associated with commercial PCB mixtures is related to the presence of about 20 planar congeners, i.e., congeners without chlorine substitution in the ortho position. Toxic planar congeners, like other PCB congeners, have been detected in virtually all analyzed samples, regardless of collection locale. Planar PCB concentrations were usually highest in samples from near urban areas and in fat and liver tissues, filter-feeding bivalve mollusks, fish-eating birds, and carnivorous marine mammals. Adverse effects of planar PCBs on growth, survival, and reproduction are highly variable because of numerous biotic and abiotic modifiers, including interaction with other chemicals. In general, embryos and juveniles were the most sensitive stages tested to planar PCBs, and the chinook salmon, domestic chicken, mink, rhesus macaque, and laboratory white rat were among the most sensitive species. for protection of natural resources, most authorities now recommend (1) analyzation of environmental samples for planar and other potentially hazardous congeners; (2) exposure studies with representative species and specific congeners, alone and in combination with other environmental contaminants; (3) clarification of existing structure

2,2′,3,5′,6-PENTACHLOROBIPHENYL (PCB 95) AND ITS HYDROXYLATED METABOLITES ARE ENANTIOMERICALLY ENRICHED IN FEMALE MICE

Science.gov (United States)

Kania-Korwel, Izabela; Barnhart, Christopher D.; Stamou, Marianna; Truong, Kim M.; El-Komy, Mohammed H.M.E.; Lein, Pamela J.; Veng-Pedersen, Peter; Lehmler, Hans-Joachim

2012-01-01

Epidemiological and laboratory studies link polychlorinated biphenyls and their metabolites to adverse neurodevelopmental outcomes. Several neurotoxic PCB congeners are chiral and undergo enantiomeric enrichment in mammalian species, which may modulate PCB developmental neurotoxicity. This study measures levels and enantiomeric enrichment of PCB 95 and its hydroxylated metabolites (OH-PCBs) in adult female C57Bl/6 mice following subchronic exposure to racemic PCB 95. Tissue levels of PCB 95 and OH-PCBs increased with increasing dose. Dose-dependent enantiomeric enrichment of PCB 95 was observed in brain and other tissues. OH-PCBs also displayed enantiomeric enrichment in blood and liver, but were not detected in adipose and brain. In light of data suggesting enantioselective effects of chiral PCBs on molecular targets linked to PCB developmental neurotoxicity, our observations highlight the importance of accounting for PCB and OH-PCB enantiomeric enrichment in the assessment of PCB developmental neurotoxicity. PMID:22974126

Measurement of hydroxylated PCB metabolites for Slovakia maternal blood serums

Energy Technology Data Exchange (ETDEWEB)

Park, J.S.; Athanasiadou, M; Bergman, A. [Stockholm Univ., Stockholm (Sweden); Charles, J.; Zhao, G.; Hertz-Picciotto, I. [California Univ., Sacramento, CA (United States); Petrik, J.; Kocan, A; Trnovec, T. [Bratislava Inst. of Preventive and Clinical Medicine, Bratislava (Slovakia)

2005-07-01

Although it is known that polychlorinated biphenyls (PCBs) have adverse impacts on human health, it is not clear if human health impacts are caused by the PCBs or their related hydroxylated (OH) PCB metabolite compounds. This study measured OH-PCB metabolites in the maternal blood serum specimens from the Svidnik and Michalovce areas in eastern Slovakia where PCBs were intensively produced and inadequately disposed. The aim of the study was to characterize and quantify levels of specific OH-PCB metabolites in Slovakian maternal serums exposed to high environmental PCB levels. All specimens were analyzed for PCBs, and a subset of the samples was analyzed for OH-PCB metabolites. The Wallenburg blood extraction method was adopted to separate the OH-PCBs from the blood serums. Final eluates and calibration standards were spiked with PCB209 as an injection standard before gas chromatography (GC) analysis. OH-PCBs in the samples range from 75{+-}9 per cent to 101{+-}11 per cent. Median concentrations of OH-PCB metabolites of Michalovce samples were approximately twice as high as for the Svidnik samples. Concentrations of OH-PCBs of Michalovce blood samples were comparable to samples obtained from northern Canadian female Inuit and Faroe Island females, and were considered to be among the highest OH-PCB concentrations obtained in human blood. It was concluded that further research is needed to understand the placental transfer of OH-PCBs to the fetus, as well as epidemiological approaches to determine the relationship between the exposure of OH-PCB metabolites and child development. 12 refs., 2 figs.

Assays of dioxins and dioxin-like compounds in actually contaminated soils using transgenic tobacco plants carrying a recombinant mouse aryl hydrocarbon receptor-mediated β-glucuronidase reporter gene expression system.

Science.gov (United States)

Inui, Hideyuki; Gion, Keiko; Utani, Yasushi; Wakai, Taketo; Kodama, Susumu; Eun, Heesoo; Kim, Yun-Seok; Ohkawa, Hideo

2012-01-01

The transgenic tobacco plant XD4V-26 carrying the recombinant mouse aryl hydrocarbon receptor XD4V-mediated β-glucuronidase (GUS) reporter gene expression system was used for assay of dioxins and dioxin-like compounds consisting of polychlorinated dibenzeno-p-dioxins, polychlorinated dibenzofurans, and coplanar polychlorinated biphenyls (Co-PCBs) in actually contaminated soils. The transgenic tobacco plant XD4V-26 showed a significant dose-dependent induced GUS activity when cultured on MS medium containing PCB126 [toxic equivalency factor (TEF) = 0.1]. In contrast, PCB169 and PCB180, which have 0.03 of TEF and unassigned TEF values, respectively, did not significantly induce GUS activity under the same conditions as with PCB126. When the tobacco plants were cultivated for up to 5 weeks on actually contaminated soils with dioxins and dioxin-like compounds collected from the periphery of an incinerator used for disposal of residential and industrial wastes, GUS activity in the leaves was dose-dependently increased. The plants clearly detected 360 pg-TEQ g(-1) of dioxins and dioxin-like compounds in this assay. There was a positive correlation between GUS activity and TEQ value of dioxins and dioxin-like compounds in the plants. This assay does not require any extraction and purification processes for the actually contaminated soil samples.

Acetylcholinesterase triggers the aggregation of PrP 106-126

International Nuclear Information System (INIS)

Pera, M.; Roman, S.; Ratia, M.; Camps, P.; Munoz-Torrero, D.; Colombo, L.; Manzoni, C.; Salmona, M.; Badia, A.; Clos, M.V.

2006-01-01

Acetylcholinesterase (AChE), a senile plaque component, promotes amyloid-β-protein (Aβ) fibril formation in vitro. The presence of prion protein (PrP) in Alzheimer's disease (AD) senile plaques prompted us to assess if AChE could trigger the PrP peptides aggregation as well. Consequently, the efficacy of AChE on the PrP peptide spanning-residues 106-126 aggregation containing a coumarin fluorescence probe (coumarin-PrP 106-126) was studied. Kinetics of coumarin-PrP 106-126 aggregation showed a significant increase of maximum size of aggregates (MSA), which was dependent on AChE concentration. AChE-PrP 106-126 aggregates showed the tinctorial and optical amyloid properties as determined by polarized light and electronic microscopy analysis. A remarkable inhibition of MSA was obtained with propidium iodide, suggesting that AChE triggers PrP 106-126 and Aβ aggregation through a similar mechanism. Huprines (AChE inhibitors) also significantly decreased MSA induced by AChE as well, unveiling the potential interest for some AChE inhibitors as a novel class of potential anti-prion drugs

Gene expression and inducibility of the aryl hydrocarbon receptor-dependent pathway in cultured bovine blood lymphocytes.

Science.gov (United States)

Girolami, Flavia; Spalenza, Veronica; Carletti, Monica; Perona, Giovanni; Sacchi, Paola; Rasero, Roberto; Nebbia, Carlo

2011-10-10

The exposure to dioxin-like (DL) compounds, an important class of persistent environmental pollutants, results in the altered expression of target genes. This occurs through the binding to the aryl hydrocarbon receptor (AhR), the subsequent dimerization with the AhR nuclear translocator (ARNT), and the binding of the complex to DNA responsive elements. A number of genes are up-regulated, including, among others, the AhR repressor (AHRR) and several biotransformation enzymes, such as the members of CYP1 family and NAD(P)H-quinone oxidoreductase (NOQ1). The expression and the inducibility of the above genes were investigated in mitogen-stimulated cultured blood lymphocytes from cattle, which represent a notable source of DL-compound human exposure through dairy products and meat. As assessed by real-time PCR, all the examined genes except CYP1A2 and NQO1 were detected under basal conditions. Cell exposure to the DL-compounds PCB126 or PCB77 in the 10(-6)-10(-9)M concentration range resulted in a 2-4-fold induction of CYPIA1 and CYP1B1, which was antagonized by α-naphthoflavone or PCB153. This study demonstrates for the first time the presence and inducibility of the AhR pathway in easily accessible cells like bovine peripheral lymphocytes and prompts further investigations to verify whether similar changes could occur under in vivo conditions. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

PCB concentrations and activity of sea lamprey Petromyzon marinus vary by sex

Science.gov (United States)

Madenjian, Charles P.; Johnson, Nicholas S.; Binder, Thomas R.; Rediske, Richard R.; O'Keefe, James P.

2013-01-01

We determined the polychlorinated biphenyl (PCB) concentrations of 40 male and 40 female adult sea lampreys Petromyzon marinus captured in the Cheboygan River, a tributary to Lake Huron, during May 2011. In addition, we performed a laboratory experiment using passive integrated transponder tags to determine whether male adult sea lampreys were more active than female adult sea lampreys. Sex had a significant effect on PCB concentration, and PCB concentration at a given level of sea lamprey condition was approximately 25 % greater in males than in females. Adjusting for the difference in condition between the sexes, males averaged a 17 % greater PCB concentration compared with females. Results from the laboratory experiment indicated that males were significantly more active than females. The observed sex difference in PCB concentrations was not due to female sea lampreys releasing eggs at spawning because the sea lamprey is semelparous, and we caught the sea lampreys before spawning. Rather, we attributed the sex difference in PCB concentrations to a greater rate of energy expenditure in males compared with females. We proposed that this greater rate of energy expenditure was likely due to greater activity. Our laboratory experiment results supported this hypothesis. A greater resting metabolic rate may also have contributed to a greater rate of energy expenditure. Our findings should eventually be applicable toward improving control of sea lamprey, a pest responsible for considerable damage to fisheries in lakes where it is not native.

Effect of a base-catalyzed dechlorination process on the genotoxicity of PCB-contaminated soil

Energy Technology Data Exchange (ETDEWEB)

DeMarini, D.M.; Houk, V.S.; Kornel, A.; Rogers, C.J.

1992-01-01

We evaluated the genotoxicity of dichloromethane (DCM) extracts of PCB-contaminated soil before and after the soil had been treated by a base-catalyzed dechlorination process, which involved heating a mixture of the soil, polyethylene glycol, and sodium hydroxide to 250-350 C. This dechlorination process reduced by over 99% the PCB concentration in the soil, which was initially 2,200 ppm. The DCM extracts of both control and treated soils were not mutagenic in strain TA100 of Salmonella, but they were mutagenic in strain TA98. The base-catalyzed dechlorination process reduced the mutagenic potency of the soil by approximately one-half. The DCM extracts of the soils before and after treatment were equally genotoxic in a prophage-induction assay in E. coli, which detects some chlorinated organic carcinogens that were not detected by the Salmonella mutagenicity assay. These results show that treatment of PCB-contaminated soil by this base-catalyzed dechlorination process did not increase the genotoxicity of the soil.

Measurement of PCB concentrations in waters using a biomonitoring programme

International Nuclear Information System (INIS)

Mast, P.G.

1993-01-01

The book describes a PCB biomonitoring programme which was developed for measuring instantaneous PCB concentrations and permits the compilation of PCB action cadastres for different types of waters and subsequent derivation of current trends. Six representative congeners were selected as a basis for the quantitative routine analysis. The fish species bream (abramis brama) and roach (rutilus rutilus) were used as indicators in the PCB biomonitoring programme on account of their distribution and ecological demands. The age and growth rate of each fish destined for analysis was determined so as to ensure that only healthy fish would be used. In both fish species the dorsal musulature with its low scatter of test results and consistent PCB pattern (internal quantification) proved a representative body region. (orig.) [de

Association of plasma PCB levels and HbA1c concentration in Iran.

Science.gov (United States)

Eftekhari, Sahar; Aminian, Omid; Moinfar, Zeinab; Schettgen, Thomas; Kaifie, Andrea; Felten, Michael; Kraus, Thomas; Esser, André

2018-01-01

The rapid increase in prevalence of diabetes mellitus over the last decades warrants more attention to the effects of environmental and occupational exposures on glucose metabolism. Our study aimed to assess the association between the plasma levels of various congeners of polychlorinated biphenyls (PCBs) and the serum concentration of glycated haemoglobin (HbA1c). Our study population consisted of 140 Iranian adults from seven different occupational groups and a group of non-occupationally exposed female participants. The plasma concentration of PCBs were determined at the laboratory of occupational toxicology at RWTH Aachen University, Germany. We considered an HbA1c concentration of 5.7% and more as indicating a disturbed glucose metabolism. Logistic regression was used to assess the association between quartiles of concentrations of PCB congeners and serum HbA1c. Participants with an increased HbA1c value had higher plasma levels of PCB 138, 153, 180 and the PCB sum, although this association was statistically not significant. There was no significant difference between the levels of PCB 138, 153, 180, the sum of these congeners, and PCB 118 in their quartiles when comparing with HbA1c concentrations. For our cohort, we could not demonstrate a significant association between PCB and HbA1c concentrations indicating a disturbance of glucose metabolism.

Sexual difference in PCB concentrations of coho salmon (Oncorhynchus kisutch)

Science.gov (United States)

Madenjian, Charles P.; Schrank, Candy S.; Begnoche, Linda J.; Elliott, Robert F.; Quintal, Richard T.

2010-01-01

We determined polychlorinated biphenyl (PCB) concentrations in 35 female coho salmon (Oncorhynchus kisutch) and 60 male coho salmon caught in Lake Michigan (Michigan and Wisconsin, United States) during the fall of 1994 and 1995. In addition, we determined PCB concentrations in the skin-on fillets of 26 female and 19 male Lake Michigan coho salmon caught during the fall of 2004 and 2006. All coho salmon were age-2 fish. These fish were caught prior to spawning, and therefore release of eggs could not account for sexual differences in PCB concentrations because female coho salmon spawn only once during their lifetime. To investigate whether gross growth efficiency (GGE) differed between the sexes, we applied bioenergetics modeling. Results showed that, on average, males were 19% higher in PCB concentration than females, based on the 1994–1995 dataset. Similarly, males averaged a 20% higher PCB concentration in their skin-on fillets compared with females. According to the bioenergetics modeling results, GGE of adult females was less than 1% higher than adult male GGE. Thus, bioenergetics modeling could not explain the 20% higher PCB concentration exhibited by the males. Nonetheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations.

Exposure in utero to 2,2',3,3',4,6'-hexachlorobiphenyl (PCB 132) impairs sperm function and alters testicular apoptosis-related gene expression in rat offspring

International Nuclear Information System (INIS)

Hsu, P.-C.; Pan, M.-H.; Li, L.-A.; Chen, C.-J.; Tsai, S.-S.; Guo, Y.L.

2007-01-01

Toxicity of the polychlorinated biphenyls (PCBs) depends on their molecular structure. Mechanisms by prenatal exposure to a non-dioxin-like PCB, 2,2',3,4',5',6-hexachlorobiphenyl (PCB 132) that may act on reproductive pathways in male offspring are relatively unknown. The purpose was to determine whether epididymal sperm function and expression of apoptosis-related genes were induced or inhibited by prenatal exposure to PCB 132. Pregnant rats were treated with a single dose of PCB 132 at 1 or 10 mg/kg on gestational day 15. Male offspring were killed and the epididymal sperm counts, motility, velocity, reactive oxygen species (ROS) generation, sperm-oocyte penetration rate (SOPR), testicular histopathology, apoptosis-related gene expression and caspase activation were assessed on postnatal day 84. Prenatal exposure to PCB 132 with a single dose of 1 or 10 mg/kg decreased cauda epididymal weight, epididymal sperm count and motile epididymal sperm count in adult offspring. The spermatozoa of PCB 132-exposed offspring produced significantly higher levels of ROS than the controls; ROS induction and SOPR reduction were dose-related. In the low-dose PCB 132 group, p53 was significantly induced and caspase-3 was inhibited. In the high-dose group, activation of caspase-3 and -9 was significantly increased, while the expressions of Fas, Bax, bcl-2, and p53 genes were significantly decreased. Gene expression and caspase activation data may provide insight into the mechanisms by which exposure to low-dose or high-dose PCB 132 affects reproduction in male offspring in rats. Because the doses of PCB 132 administered to the dams were approximately 625-fold in low-dose group and 6250-fold higher in high-dose group than the concentration in human tissue levels, the concentrations are not biologically or environmentally relevant. Further studies using environmentally relevant doses are needed for hazard identification

Treating PCB contaminated light ballasts

International Nuclear Information System (INIS)

Day, B.

1995-01-01

Development and salient features of CON TECH PCB, a light ballast reduction process to allow PCB waste owners to best utilize storage space for the long-term regulated storage of PCBs, or to prepare them for final destruction and to reduce destruction costs, was reviewed. The essence of the process is ballast splitting, i.e. the breaking of the ballast and removing the capacitor containing the toxic PCBs. The work is done in a specially fitted mobile processing unit, thus reducing the storage requirements by better than 50 per cent. Details of the process and some cost and storage facility estimates were provided

Developmental Exposure to an Environmental PCB Mixture Delays the Propagation of Kindling in the Amygdala

Science.gov (United States)

Developmental PCB exposure impairs hearing and induces brainstem audiogenic seizures in adult offspring. The degree to which this enhanced susceptibility to seizure is manifest in other brain regions has not been examined. Thus, electrical kindling of the amygdala was used to eva...

Bioavailability of 2,3',4,4',5-pentachlorobiphenyl (PCB118) and 2,2',5,5'-tetrachlorobiphenyl (PCB52) from soils using a rat model and a physiologically based extraction test

International Nuclear Information System (INIS)

Pu Xinzhu; Lee, Linda S.; Galinsky, Raymond E.; Carlson, Gary P.

2006-01-01

The bioavailability of coplanar 2,3',4,4',5-pentachlorobiphenyl (PCB118) and nonplanar 2,2',5,5'-tetrachlorobiphenyl (PCB52) from soils representing a range in organic carbon (OC), clay content and pH were investigated using an in vivo rat model and an in vitro physiologically based extraction test (PBET) to assess the role of soil and chemical properties on bioavailabilty. Affinity to soil and persistence of PCBs have been shown to increase with increasing soil organic carbon (OC) content, PCB chlorination, and PCB coplanarity. In the in vivo tests for both PCB118 and PCB52, the AUCs following iv injection were significantly higher than the AUCs for all soil groups, indicating that the soil matrix can reduce the absolute bioavailability of PCB118 and PCB52. However, no significant differences were detected between soils of different properties. In the in vitro PBET, significant differences in the mobilization of PCB118 and PCB52 were observed among soils, and PCBs had the least mobilization from the soil with the highest OC content consistent with hydrophobic partitioning theory. Also, significantly less PCB118 was mobilized relative to PCB52 in the PBET assay, showing the potential impact of spatial orientation and chlorine content on bioavailability. No correlation between the in vitro PBET and the in vivo rat model was observed for the PCBs. Although the in vitro PBET and related assays may serve as an indicator of bioavailability, it is likely to underestimate what can be released from a soil in an in vivo assay

Long-term effects of environmentally relevant doses of 2,2',4,4',5,5' hexachlorobiphenyl (PCB153 on neurobehavioural development, health and spontaneous behaviour in maternally exposed mice

Directory of Open Access Journals (Sweden)

Heegaard Einar

2011-01-01

Full Text Available Abstract Background Polychlorinated biphenyls (PCBs are widespread in the environment, human food and breast milk. Seafood is known to contain nutrients beneficial for the normal development and function of the brain, but also contaminants such as PCBs which are neurotoxic. Exposure to non-coplanar PCBs during brain development can disrupt spontaneous behaviour in mice and lead to hyperactive behaviour. Humans are chronically exposed to the highest relative levels of organochlorines in early childhood during brain development, though usually at doses which do not give clinical symptoms of toxicity. This study aimed to elucidate the developmental and behavioural effects of 2,2',4,4',5,5' hexachlorobiphenyl (PCB153 in mice, mimicking human exposure during gestation and lactation. Methods Environmentally relevant doses of PCB153 were added to the experimental diets. Feed concentrations were approximately 0.5, 6.5, and 1500 μg PCB153/kg feed, representing a realistic and a worst case scenario of frequent consumption of contaminated fish. The study also investigated the effects of maternal nutrition, i.e. a standard rodent diet versus a high inclusion of salmon. Mice pups were examined for physical- and reflex development, sensorimotor function and spontaneous behaviour from five days after birth until weaning. A selection of pups were followed until 16 weeks of age and tested for open field behaviour and the acoustic startle response (ASR with prepulse inhibition (PPI. Blood thyroid hormones and liver enzymes, blood lipids and PCB153 content in fat were examined at 16 weeks. Statistical analyses modelled the three way interactions of diet, PCB exposure and litter size on behaviour, using generalized linear models (GLM and linear mixed effect models (LME. The litter was used as a random variable. Non-parametric tests were used for pair wise comparisons of biochemical analyses. Results Litter size consistently influenced pup development and behaviour

Long-term effects of environmentally relevant doses of 2,2',4,4',5,5' hexachlorobiphenyl (PCB153) on neurobehavioural development, health and spontaneous behaviour in maternally exposed mice.

Science.gov (United States)

Haave, Marte; Bernhard, Annette; Jellestad, Finn K; Heegaard, Einar; Brattelid, Trond; Lundebye, Anne-Katrine

2011-01-13

Polychlorinated biphenyls (PCBs) are widespread in the environment, human food and breast milk. Seafood is known to contain nutrients beneficial for the normal development and function of the brain, but also contaminants such as PCBs which are neurotoxic. Exposure to non-coplanar PCBs during brain development can disrupt spontaneous behaviour in mice and lead to hyperactive behaviour. Humans are chronically exposed to the highest relative levels of organochlorines in early childhood during brain development, though usually at doses which do not give clinical symptoms of toxicity. This study aimed to elucidate the developmental and behavioural effects of 2,2',4,4',5,5' hexachlorobiphenyl (PCB153) in mice, mimicking human exposure during gestation and lactation. Environmentally relevant doses of PCB153 were added to the experimental diets. Feed concentrations were approximately 0.5, 6.5, and 1500 μg PCB153/kg feed, representing a realistic and a worst case scenario of frequent consumption of contaminated fish. The study also investigated the effects of maternal nutrition, i.e. a standard rodent diet versus a high inclusion of salmon. Mice pups were examined for physical- and reflex development, sensorimotor function and spontaneous behaviour from five days after birth until weaning. A selection of pups were followed until 16 weeks of age and tested for open field behaviour and the acoustic startle response (ASR) with prepulse inhibition (PPI). Blood thyroid hormones and liver enzymes, blood lipids and PCB153 content in fat were examined at 16 weeks. Statistical analyses modelled the three way interactions of diet, PCB exposure and litter size on behaviour, using generalized linear models (GLM) and linear mixed effect models (LME). The litter was used as a random variable. Non-parametric tests were used for pair wise comparisons of biochemical analyses. Litter size consistently influenced pup development and behaviour. Few lasting PCB153 related changes were observed

Cultured human peripheral blood mononuclear cells alter their gene expression when challenged with endocrine-disrupting chemicals

International Nuclear Information System (INIS)

Wens, B.; De Boever, P.; Verbeke, M.; Hollanders, K.; Schoeters, G.

2013-01-01

Endocrine disrupting chemicals (EDCs) have the potential to interfere with the hormonal system and may negatively influence human health. Microarray analysis was used in this study to investigate differential gene expression in human peripheral blood cells (PBMCs) after in vitro exposure to EDCs. PBMCs, isolated from blood samples of four male and four female healthy individuals, were exposed in vitro for 18 h to either a dioxin-like polychlorinated biphenyl (PCB126, 1 μM), a non-dioxin-like polychlorinated biphenyl (PCB153, 10 μM), a brominated flame retardant (BDE47, 10 μM), a perfluorinated alkyl acid (PFOA, 10 μM) or bisphenol (BPA, 10 μM). ANOVA analysis revealed a significant change in the expression of 862 genes as a result of EDC exposure. The gender of the donors did not affect gene expression. Hierarchical cluster analysis created three groups and clustered: (1) PCB126-exposed samples, (2) PCB153 and BDE47, (3) PFOA and BPA. The number of differentially expressed genes varied per compound and ranged from 60 to 192 when using fold change and multiplicity corrected p-value as filtering criteria. Exposure to PCB126 induced the AhR signaling pathway. BDE47 and PCB153 are known to disrupt thyroid metabolism and exposure influenced the expression of the nuclear receptors PPARγ and ESR2, respectively. BPA and PFOA did not induce significant changes in the expression of known nuclear receptors. Overall, each compound produced a unique gene expression signature affecting pathways and GO processes linked to metabolism and inflammation. Twenty-nine genes were significantly altered in expression under all experimental conditions. Six of these genes (HSD11B2, MMP11, ADIPOQ, CEL, DUSP9 and TUB) could be associated with obesity and metabolic syndrome. In conclusion, microarray analysis identified that PBMCs altered their gene expression response in vitro when challenged with EDCs. Our screening approach has identified a number of gene candidates that warrant

Prenatal exposure to a polychlorinated biphenyl (PCB congener influences fixation duration on biological motion at 4-months-old: a preliminary study.

Directory of Open Access Journals (Sweden)

Hirokazu Doi

Full Text Available Adverse effects of prenatal exposure to polychlorinated biphenyl (PCB congeners on postnatal brain development have been reported in a number of previous studies. However, few studies have examined the effects of prenatal PCB exposure on early social development. The present study sought to increase understanding of the neurotoxicity of PCBs by examining the relationship between PCB congener concentrations in umbilical cord blood and fixation patterns when observing upright and inverted biological motion (BM at four-months after birth. The development of the ability to recognize BM stimuli is considered a hallmark of socio-cognitive development. The results revealed a link between dioxin-like PCB #118 concentration and fixation pattern. Specifically, four-month-olds with a low-level of prenatal exposure to PCB #118 exhibited a preference for the upright BM over inverted BM, whereas those with a relatively high-level of exposure did not. This finding supports the proposal that prenatal PCB exposure impairs the development of social functioning, and indicates the importance of congener-specific analysis in the risk analysis of the adverse effects of PCB exposure on the brain development.

Molecular interaction of PCB153 to human serum albumin: Insights from spectroscopic and molecular modeling studies

Energy Technology Data Exchange (ETDEWEB)

Han, Chao; Fang, Senbiao; Cao, Huiming; Lu, Yan; Ma, Yaqiong [School of Pharmacy, Lanzhou University, Lanzhou 730000 (China); Wei, Dongfeng [Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing 100700 (China); Xie, Xiaoyun [College of Earth and Environmental Science, Lanzhou University, Lanzhou 730000 (China); Liu, Xiaohua [School of Pharmacy, Lanzhou University, Lanzhou 730000 (China); Li, Xin [College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471003 (China); Fei, Dongqing [School of Pharmacy, Lanzhou University, Lanzhou 730000 (China); Zhao, Chunyan, E-mail: zhaochy07@lzu.edu.cn [School of Pharmacy, Lanzhou University, Lanzhou 730000 (China)

2013-03-15

Highlights: ► We identify the binding mode of PCB153 to human serum albumin (HSA). ► Spectroscopic and molecular modeling results reveal that PCB153 binds at the site II. ► The interaction is mainly governed by hydrophobic and hydrogen bond forces. ► The work helps to probe transporting, distribution and toxicity effect of PCBs. -- Abstract: Polychlorinated biphenyls (PCBs) possessed much potential hazard to environment because of its chemical stability and biological toxicity. Here, we identified the binding mode of a representative compound, PCB153, to human serum albumin (HSA) using fluorescence and molecular dynamics simulation methods. The fluorescence study showed that the intrinsic fluorescence of HSA was quenched by addition of PCB153 through a static quenching mechanism. The thermodynamic analysis proved the binding behavior was mainly governed by hydrophobic force. Furthermore, as evidenced by site marker displacement experiments using two probe compounds, it revealed that PCB153 acted exactly on subdomain IIIA (site II) of HSA. On the other hand, the molecular dynamics studies as well as free energy calculations made another important contribution to understand the conformational changes of HSA and the stability of HSA-PCB153 system. Molecular docking revealed PCB153 can bind in a large hydrophobic activity of subdomain IIIA by the hydrophobic interaction and hydrogen bond interactions between chlorine atoms and residue ASN391. The present work provided reasonable models helping us further understand the transporting, distribution and toxicity effect of PCBs when it spread into human blood serum.

Hydroxylated polychlorinated biphenyls increase reactive oxygen species formation and induce cell death in cultured cerebellar granule cells

International Nuclear Information System (INIS)

Dreiem, Anne; Rykken, Sidsel; Lehmler, Hans-Joachim; Robertson, Larry W.; Fonnum, Frode

2009-01-01

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that bioaccumulate in the body, however, they can be metabolized to more water-soluble products. Although they are more readily excreted than the parent compounds, some of the metabolites are still hydrophobic and may be more available to target tissues, such as the brain. They can also cross the placenta and reach a developing foetus. Much less is known about the toxicity of PCB metabolites than about the parent compounds. In the present study, we have investigated the effects of eight hydroxylated (OH) PCB congeners (2'-OH PCB 3, 4-OH PCB 14, 4-OH PCB 34, 4'-OH PCB 35, 4-OH PCB 36, 4'-OH PCB 36, 4-OH PCB 39, and 4'-OH PCB 68) on reactive oxygen species (ROS) formation and cell viability in rat cerebellar granule cells. We found that, similar to their parent compounds, OH-PCBs are potent ROS inducers with potency 4-OH PCB 14 < 4-OH PCB 36 < 4-OH PCB 34 < 4'-OH PCB 36 < 4'-OH PCB 68 < 4-OH PCB 39 < 4'-OH PCB 35. 4-OH PCB 36 was the most potent cell death inducer, and caused apoptotic or necrotic morphology depending on concentration. Inhibition of ERK1/2 kinase with U0126 reduced both cell death and ROS formation, suggesting that ERK1/2 activation is involved in OH-PCB toxicity. The results indicate that the hydroxylation of PCBs may not constitute a detoxification reaction. Since OH-PCBs like their parent compounds are retained in the body and may be more widely distributed to sensitive tissues, it is important that not only the levels of the parent compounds but also the levels of their metabolites are taken into account during risk assessment of PCBs and related compounds.

Radioactive and non-radioactive polychlorinated biphenyl (PCB) management at Hanford

International Nuclear Information System (INIS)

Leonard, W.W.; Gretzinger, R.F.; Cox, G.R.

1986-01-01

Conformance to all state and federal regulations is the goal of Rockwell in the management of both radioactive and non-radioactive PCB's at Hanford. A continuing effort is being made to locate, remove, and properly dispose of all PCB's. As improved methods of management are developed, consideration will be given to them for their adaptation into the Hanford Site PCB Management Plan

PCB-Based Break-Out Box

Science.gov (United States)

Lee, Jason H.

2011-01-01

Break-out boxes (BOBs) are necessary for all electrical integration/cable checkouts and troubleshooting. Because the price of a BOB is high, and no work can be done without one, often the procedure stops, simply waiting for a BOB. A less expensive BOB would take less time in the integration, testing, and troubleshooting process. The PCB-based BOB works and looks the same as a standard JPL BOB, called Gold Boxes. The only differences between the old BOB and the new PCB-based BOB is that the new one has 80 percent of its circuitry in a printed circuit board. This process reduces the time for fabrication, thus making the BOBs less expensive. Moreover, because of its unique design, the new BOBs can be easily assembled and fixed. About 80 percent of the new PCB-based BOB is in a $22 (at the time of this reporting) custom-designed, yet commercially available PCB. This device has been used successfully to verify that BOB cables were properly made. Also, upon completion, the BOB was beeped out via a multimeter to ensure that all sockets on the connectors were properly connected to the respective banana jack. When compared to the Gold Box BOBs, the new BOB has many advantages. It is much more cost efficient, it delivers equal usability at substantially lower cost of the BOB, and the Gold Box is much heavier when compared to the new BOB. The new BOB is also a bit longer and much more versatile in that connectors are easily changeable and if a banana jack is broken, it can be replaced instead of throwing away an entire BOB.

Milk transfer and neonatal uptake of coplanar polychlorinated biphenyl (PCB) congeners in mice

Energy Technology Data Exchange (ETDEWEB)

Sinjari, T. [Uppsala Univ., Dept. of Pharmaceutical Biosciences, Div. of Toxicology, Uppsala (Sweden); Klasson-Wehler, W. [Stockholm Univ., Wallenberg Lb., Environmental Chemistry, Stockholm (Sweden); Oskarsson, A. [Swedish Univ. of Agricultural Science, Dept. of Food Hygiene, Uppsala (Sweden); Darnerud, P.O. [National Food Administration, Toxicology Div., uppsala (Sweden)

1996-03-01

The selective accumulation of 3,3`4,3`-tetrachlorobiphenyl metabolites in late gestational fetal blood and soft tissues in mice as a result of administration of different coplanar polychlorinated biphenyl (PCB) congeners, is reported elsewhere. The situation in the nursing neonate after maternal exposure to the same congeners is now studied: The {sup 14}C-labelled congeners 3,3`,4,4`-tetrachlorobiphenyl (IUPAC number CB-77), 3,3`,4,4`,5-pentachlorobiphenyl (IUPAC number CB-126), 3,3`4,4`5,5`-hexachlorobiphenyl (IUPAC number CB-169) (all three non-ortho congeners) and 2,3,3`,4,4`-pentachlorobiphenyl (IUPAC number CB-105) (mono-ortho congener) were injected intravenously in lactating mice at day 11 post partum. One day and four days later, milk and neonatal/maternal tissues and plasma radioactivity was monitored by liquid scintillation counting (dose: 2.0 {mu}mol (20-50 {mu}Ci)/kg body weight). In milk, CB-126, -169 and -105 showed higher levels (1450-2520 pmol/ml; one day after administration) than did CB-77 (580 pmol/ml), and in neonates, the relative whole-body levels of radioactivity were related to the levels seen in milk (probably the consequences of their metabolic persistence). The comparably high {sup 14}C-concentration found in neonatal liver (about 15,000 pmol/kg) after CB-126 administration and in plasma (880 pmol/ml) after CB-77 administration could be explained by binding to specific proteins. In general, neonatal mice had two to seven times higher plasma levels than those of their mothers. These results indicate that CB-126, -169 and -105 are transferred via milk to neonates in considerable quantity and are deposited in neonatal liver, whereas CB-77 is transferred in a comparably lower amount and accumulated in neonatal plasma. The lower {sup 14}C-levels in the NMRI mothers and offspring (about half of C57BL values in maternal and neonatal plasma), could possibly be explained by a differentiated metabolism of CB-77 in these two strains.

A dynamic and mechanistic model of PCB bioaccumulation in the European hake ( Merluccius merluccius)

Science.gov (United States)

Bodiguel, Xavier; Maury, Olivier; Mellon-Duval, Capucine; Roupsard, François; Le Guellec, Anne-Marie; Loizeau, Véronique

2009-08-01

Bioaccumulation is difficult to document because responses differ among chemical compounds, with environmental conditions, and physiological processes characteristic of each species. We use a mechanistic model, based on the Dynamic Energy Budget (DEB) theory, to take into account this complexity and study factors impacting accumulation of organic pollutants in fish through ontogeny. The bioaccumulation model proposed is a comprehensive approach that relates evolution of hake PCB contamination to physiological information about the fish, such as diet, metabolism, reserve and reproduction status. The species studied is the European hake ( Merluccius merluccius, L. 1758). The model is applied to study the total concentration and the lipid normalised concentration of 4 PCB congeners in male and female hakes from the Gulf of Lions (NW Mediterranean sea) and the Bay of Biscay (NE Atlantic ocean). Outputs of the model compare consistently to measurements over the life span of fish. Simulation results clearly demonstrate the relative effects of food contamination, growth and reproduction on the PCB bioaccumulation in hake. The same species living in different habitats and exposed to different PCB prey concentrations exhibit marked difference in the body accumulation of PCBs. At the adult stage, female hakes have a lower PCB concentration compared to males for a given length. We successfully simulated these sex-specific PCB concentrations by considering two mechanisms: a higher energy allocation to growth for females and a transfer of PCBs from the female to its eggs when allocating lipids from reserve to eggs. Finally, by its mechanistic description of physiological processes, the model is relevant for other species and sets the stage for a mechanistic understanding of toxicity and ecological effects of organic contaminants in marine organisms.

Silicon photonic IC embedded optical-PCB for high-speed interconnect application

Science.gov (United States)

Kallega, Rakshitha; Nambiar, Siddharth; Kumar, Abhai; Ranganath, Praveen; Selvaraja, Shankar Kumar

2018-02-01

Optical-Printed Circuit Board (PCB) is an emerging optical interconnect technology to bridge the gap between the board edge and the processing module. The technology so far has been used as a broadband transmitter using polymer waveguides in the PCB. In this paper, we report a Silicon Nitride based photonic IC embedded in the PCB along with the polymers as waveguides in the PCB. The motivation for such integration is to bring routing capability and to reduce the power loss due to broadcasting mode.

Reference standards for quantitative trace analysis of PCB's by GC. Technical PCB formulations for the calibration of ECD and MSD responses

NARCIS (Netherlands)

Krupcik, J.; Kocan, A.; Petrik, J.; Leclercq, P.A.; Ballschmiter, K.

1993-01-01

The compn. of any tech. PCB formulation can be detd. directly by analyzing the PCB sample by gas chromatog. with a flame ionization detector (GC-FID), provided the relative mol. masses of the components are known. The responses of electron capture and selected-ion monitoring, mass-spectra detectors

Treatment of a suspension of PCB contaminated soil using iron nanoparticles and electric current

DEFF Research Database (Denmark)

Comes, Helena I.; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

2015-01-01

Contaminated soils and sediments with polychlorinated biphenyls (PCB) are an important environmental problem due to the persistence of these synthetic aromatic compounds and to the lack of a cost-effective and sustainable remediation technology. Recently, a new experimental setup has been proposed...... using electrodialytic remediation and iron nanoparticles. The current work compares the performance of this new setup (A) with conventional electrokinetics (setup B). An historically contaminated soil with an initial PCB concentration of 258 mu g kg-1 was treated during 5, 10, 20 and 45 d using...... different amounts of iron nanoparticles in both setups A and B. A PCB removal of 83% was obtained in setup A compared with 58% of setup B. Setup A also showed additional advantages, such as a higher PCB dechlorination, in a shorter time, with lower nZVI consumption, and with the use of half of the voltage...

Sexual difference in PCB concentrations of lake trout (Salvelinus namaycush) from Lake Ontario

Science.gov (United States)

Madenjian, Charles P.; Keir, Michael J.; Whittle, D. Michael; Noguchi, George E.

2010-01-01

We determined polychlorinated biphenyl (PCB) concentrations in 61 female lake trout (Salvelinus namaycush) and 71 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). To estimate the expected change in PCB concentration due to spawning, PCB concentrations in gonads and in somatic tissue of lake trout were also determined. In addition, bioenergetics modeling was applied to investigate whether gross growth efficiency (GGE) differed between the sexes. Results showed that, on average, males were 22% higher in PCB concentration than females in Lake Ontario. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 3% and 14% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in male lake trout. According to the bioenergetics modeling results, GGE of males was about 2% higher than adult female GGE, on average. Thus, bioenergetics modeling could not explain the higher PCB concentrations exhibited by the males. Nevertheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations of the lake trout.

Chamber study of PCB emissions from caulking materials and light ballasts.

Science.gov (United States)

Liu, Xiaoyu; Guo, Zhishi; Krebs, Kenneth A; Stinson, Rayford A; Nardin, Joshua A; Pope, Robert H; Roache, Nancy F

2015-10-01

The emissions of polychlorinated biphenyl (PCB) congeners from thirteen caulk samples were tested in a micro-chamber system. Twelve samples were from PCB-contaminated buildings and one was prepared in the laboratory. Nineteen light ballasts collected from buildings that represent 13 different models from five manufacturers were tested in 53-L environmental chambers. The rates of PCB congener emissions from caulking materials and light ballasts were determined. Several factors that may have affected the emission rates were evaluated. The experimentally determined emission factors showed that, for a given PCB congener, there is a linear correlation between the emission factor and the concentration of the PCB congener in the source. Furthermore, the test results showed that an excellent log-linear correlation exists between the normalized emission factor and the vapor pressure (coefficient of determination, r(2)⩾0.8846). The PCB congener emissions from ballasts at or near room temperature were relatively low with or without electrical load. However, the PCB congener emission rates increased significantly as the temperature increased. The results of this research provide new data and models for ranking the primary sources of PCBs and supports the development and refinement of exposure assessment models for PCBs. Published by Elsevier Ltd.

PCB dechlorination hotspots and reductive dehalogenase genes in sediments from a contaminated wastewater lagoon.

Science.gov (United States)

Mattes, Timothy E; Ewald, Jessica M; Liang, Yi; Martinez, Andres; Awad, Andrew; Richards, Patrick; Hornbuckle, Keri C; Schnoor, Jerald L

2017-08-12

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants that are distributed worldwide. Although industrial PCB production has stopped, legacy contamination can be traced to several different commercial mixtures (e.g., Aroclors in the USA). Despite their persistence, PCBs are subject to naturally occurring biodegradation processes, although the microbes and enzymes involved are poorly understood. The biodegradation potential of PCB-contaminated sediments in a wastewater lagoon located in Virginia (USA) was studied. Total PCB concentrations in sediments ranged from 6.34 to 12,700 mg/kg. PCB congener profiles in sediment sample were similar to Aroclor 1248; however, PCB congener profiles at several locations showed evidence of dechlorination. The sediment microbial community structure varied among samples but was dominated by Proteobacteria and Firmicutes. The relative abundance of putative dechlorinating Chloroflexi (including Dehalococcoides sp.) was 0.01-0.19% among the sediment samples, with Dehalococcoides sp. representing 0.6-14.8% of this group. Other possible PCB dechlorinators present included the Clostridia and the Geobacteraceae. A PCR survey for potential PCB reductive dehalogenase genes (RDases) yielded 11 sequences related to RDase genes in PCB-respiring Dehalococcoides mccartyi strain CG5 and PCB-dechlorinating D. mccartyi strain CBDB1. This is the first study to retrieve potential PCB RDase genes from unenriched PCB-contaminated sediments.

Histopathology of feral fish from a PCB-contaminated freshwater lake

Energy Technology Data Exchange (ETDEWEB)

Koponen, Kari; Ritola, Ossi; Huuskonen, Sirpa E.; Lindstroem-Seppae, Pirjo [Univ. of Kuopio (Finland). Dept. of Physiology; Myers, Mark S. [National Oceanic and Atmospheric Administration, Seattle, WA (United States). National Marine Fisheries Service

2001-05-01

The purpose of this study was to evaluate the potential toxic effects of chronic sublethal polychlorinated biphenyl (PCB) exposure on feral fish, using histopathology as an endpoint. Histopathological study of bream (Abramis brama) and asp (Aspius aspius) living in a PCB-polluted freshwater lake revealed abnormal cellular changes in the renal corpuscle of both species. Dilation of glomerular capillaries (DGC), mesangial edema (ME), an adhesion between visceral and parietal layers of Bowman's capsule (ABC), and filling of Bowman's space (FBS), were highly prevalent features in lake fish. The prevalence of each of these lesions was significantly lower, or totally absent in fish caught from reference locations. Cellular alterations in liver, gill, gonads, spleen, and intestine were all linked to seasonal changes. The results suggest that some of the observed histopathological changes in renal glomeruli, particularly DGC and ME, could possibly indicate a prolonged chemical stress caused by PCBs and related compounds. It is also possible that chronic PCB exposure may have suppressed and weakened the immuno systems of exposed fish making them more vulnerable to secondary parasitic infection.

Microbial community analysis of switchgrass planted and unplanted soil microcosms displaying PCB dechlorination.

Science.gov (United States)

Liang, Yi; Meggo, Richard; Hu, Dingfei; Schnoor, Jerald L; Mattes, Timothy E

2015-08-01

Polychlorinated biphenyls (PCBs) pose potential risks to human and environmental health because they are carcinogenic, persistent, and bioaccumulative. In this study, we investigated bacterial communities in soil microcosms spiked with PCB 52, 77, and 153. Switchgrass (Panicum virgatum) was employed to improve overall PCB removal, and redox cycling (i.e., sequential periods of flooding followed by periods of no flooding) was performed in an effort to promote PCB dechlorination. Lesser chlorinated PCB transformation products were detected in all microcosms, indicating the occurrence of PCB dechlorination. Terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis showed that PCB spiking, switchgrass planting, and redox cycling affected the microbial community structure. Putative organohalide-respiring Chloroflexi populations, which were not found in unflooded microcosms, were enriched after 2 weeks of flooding in the redox-cycled microcosms. Sequences classified as Geobacter sp. were detected in all microcosms and were most abundant in the switchgrass-planted microcosm spiked with PCB congeners. The presence of possible organohalide-respiring bacteria in these soil microcosms suggests that they play a role in PCB dechlorination therein.

Simultaneous electrodialytic removal of PAH, PCB, TBT and heavy metals from sediments

DEFF Research Database (Denmark)

Pedersen, Kristine B.; Lejon, Tore; Jensen, Pernille Erland

2017-01-01

with the need of different remedial actions for each pollutant. In this study, electrodialytic remediation (EDR) of sediments was found effective for simultaneous removal of heavy metals and organic pollutants for sediments from Arctic regions - Sisimiut in Greenland and Hammerfest in Norway. The influence...... was found to be important for the removal of heavy metals and TBT, while photolysis was significant for removal of PAH, PCB and TBT. In addition, dechlorination was found to be important for the removal of PCB. The highest removal efficiencies were found for heavy metals, TBT and PCB (>40%) and lower......Contaminated sediments are remediated in order to protect human health and the environment, with the additional benefit of using the treated sediments for other activities. Common for many polluted sediments is the contamination with several different pollutants, making remediation challenging...

Bioremediation trial on aged PCB-polluted soils--a bench study in Iceland.

Science.gov (United States)

Lehtinen, Taru; Mikkonen, Anu; Sigfusson, Bergur; Ólafsdóttir, Kristín; Ragnarsdóttir, Kristín Vala; Guicharnaud, Rannveig

2014-02-01

Polychlorinated biphenyls (PCBs) pose a threat to the environment due to their high adsorption capacity to soil organic matter, stability and low reactivity, low water solubility, toxicity and ability to bioaccumulate. With Icelandic soils, research on contamination issues has been very limited and no data has been reported either on PCB degradation potential or rate. The goals of this research were to assess the bioavailability of aged PCBs in the soils of the old North Atlantic Treaty Organization facility in Keflavík, Iceland and to find the best biostimulation method to decrease the pollution. The effectiveness of different biostimulation additives (N fertiliser, white clover and pine needles) at different temperatures (10 and 30 °C) and oxygen levels (aerobic and anaerobic) were tested. PCB bioavailability to soil fauna was assessed with earthworms (Eisenia foetida). PCBs were bioavailable to earthworms (bioaccumulation factor 0.89 and 0.82 for earthworms in 12.5 ppm PCB soil and in 25 ppm PCB soil, respectively), with less chlorinated congeners showing higher bioaccumulation factors than highly chlorinated congeners. Biostimulation with pine needles at 10 °C under aerobic conditions resulted in nearly 38 % degradation of total PCBs after 2 months of incubation. Detection of the aerobic PCB degrading bphA gene supports the indigenous capability of the soils to aerobically degrade PCBs. Further research on field scale biostimulation trials with pine needles in cold environments is recommended in order to optimise the method for onsite remediation.

Effects of age, adipose percent, and reproduction on PCB concentrations and profiles in an extreme fasting North Pacific marine mammal.

Directory of Open Access Journals (Sweden)

Sarah H Peterson

Full Text Available Persistent organic pollutants, including polychlorinated biphenyls (PCBs, are widely distributed and detectable far from anthropogenic sources. Northern elephant seals (Mirounga angustirostris biannually travel thousands of kilometers to forage in coastal and open-ocean regions of the northeast Pacific Ocean and then return to land where they fast while breeding and molting. Our study examined potential effects of age, adipose percent, and the difference between the breeding and molting fasts on PCB concentrations and congener profiles in blubber and serum of northern elephant seal females. Between 2005 and 2007, we sampled blubber and blood from 58 seals before and after a foraging trip, which were then analyzed for PCBs. Age did not significantly affect total PCB concentrations; however, the proportion of PCB congeners with different numbers of chlorine atoms was significantly affected by age, especially in the outer blubber. Younger adult females had a significantly greater proportion of low-chlorinated PCBs (tri-, tetra-, and penta-CBs than older females, with the opposite trend observed for hepta-CBs, indicating that an age-associated process such as parity (birth may significantly affect congener profiles. The percent of adipose tissue had a significant relationship with inner blubber PCB concentrations, with the highest mean concentrations observed at the end of the molting fast. These results highlight the importance of sampling across the entire blubber layer when assessing contaminant levels in phocid seals and taking into account the adipose stores and reproductive status of an animal when conducting contaminant research.

Small stress molecules inhibit aggregation and neurotoxicity of prion peptide 106-126

International Nuclear Information System (INIS)

Kanapathipillai, Mathumai; Ku, Sook Hee; Girigoswami, Koyeli; Park, Chan Beum

2008-01-01

In prion diseases, the posttranslational modification of host-encoded prion protein PrP c yields a high β-sheet content modified protein PrP sc , which further polymerizes into amyloid fibrils. PrP106-126 initiates the conformational changes leading to the conversion of PrP c to PrP sc . Molecules that can defunctionalize such peptides can serve as a potential tool in combating prion diseases. In microorganisms during stressed conditions, small stress molecules (SSMs) are formed to prevent protein denaturation and maintain protein stability and function. The effect of such SSMs on PrP106-126 amyloid formation is explored in the present study using turbidity, atomic force microscopy (AFM), and cellular toxicity assay. Turbidity and AFM studies clearly depict that the SSMs-ectoine and mannosylglyceramide (MGA) inhibit the PrP106-126 aggregation. Our study also connotes that ectoine and MGA offer strong resistance to prion peptide-induced toxicity in human neuroblastoma cells, concluding that such molecules can be potential inhibitors of prion aggregation and toxicity

Monitoring OH-PCBs in PCB transport worker's urine as a non-invasive exposure assessment tool.

Science.gov (United States)

Haga, Yuki; Suzuki, Motoharu; Matsumura, Chisato; Okuno, Toshihiro; Tsurukawa, Masahiro; Fujimori, Kazuo; Kannan, Narayanan; Weber, Roland; Nakano, Takeshi

2018-04-14

In this study, we analyzed hydroxylated polychlorinated biphenyls (OH-PCBs) in urine of both PCB transport workers and PCB researchers. A method to monitor OH-PCB in urine was developed. Urine was solid-phase extracted with 0.1% ammonia/ methanol (v/v) and glucuronic acid/sulfate conjugates and then decomposed using β-glucuronidase/arylsulfatase. After alkaline digestion/derivatization, the concentration of OH-PCBs was determined by HRGC/HRMS-SIM. In the first sampling campaign, the worker's OH-PCB levels increased several fold after the PCB waste transportation work, indicating exposure to PCBs. The concentration of OH-PCBs in PCB transport workers' urine (0.55~11 μg/g creatinine (Cre)) was higher than in PCB researchers' urine (PCB storage area. In the second sampling, after recommended PCB exposure reduction measures had been enacted, the worker's PCB levels did not increase during handling of PCB equipment. This suggests that applied safety measures improved the situation. Hydroxylated trichlorobiphenyls (OH-TrCBs) were identified as a major homolog of OH-PCBs in urine. Also, hydroxylated tetrachlorobiphenyls (OH-TeCBs) to hydroxylated hexachlorobiphenyls (OH-HxCBs) were detected. For the sum of ten selected major indicators, a strong correlation to total OH-PCBs were found and these can possibly be used as non-invasive biomarkers of PCB exposure in workers managing PCB capacitors and transformer oils. We suggest that monitoring of OH-PCBs in PCB management projects could be considered a non-invasive way to detect exposure. It could also be used as a tool to assess and improve PCB management. This is highly relevant considering the fact that in the next 10 years, approx. 14 million tons of PCB waste need to be managed. Also, the selected populations could be screened to assess whether exposure at work, school, or home has taken place.

Estimating dermal transfer from PCB-contaminated porous surfaces.

Science.gov (United States)

Slayton, T M; Valberg, P A; Wait, A D

1998-06-01

Health risks posed by dermal contact with PCB-contaminated porous surfaces have not been directly demonstrated and are difficult to estimate indirectly. Surface contamination by organic compounds is commonly assessed by collecting wipe samples with hexane as the solvent. However, for porous surfaces, hexane wipe characterization is of limited direct use when estimating potential human exposure. Particularly for porous surfaces, the relationship between the amount of organic material collected by hexane and the amount actually picked up by, for example, a person's hand touch is unknown. To better mimic PCB pickup by casual hand contact with contaminated concrete surfaces, we used alternate solvents and wipe application methods that more closely mimic casual dermal contact. Our sampling results were compared to PCB pickup using hexane-wetted wipes and the standard rubbing protocol. Dry and oil-wetted samples, applied without rubbing, picked up less than 1% of the PCBs picked up by the standard hexane procedure; with rubbing, they picked up about 2%. Without rubbing, saline-wetted wipes picked up 2.5%; with rubbing, they picked up about 12%. While the nature of dermal contact with a contaminated surface cannot be perfectly reproduced with a wipe sample, our results with alternate wiping solvents and rubbing methods more closely mimic hand contact than the standard hexane wipe protocol. The relative pickup estimates presented in this paper can be used in conjunction with site-specific PCB hexane wipe results to estimate dermal pickup rates at sites with PCB-contaminated concrete.

Ionic mechanisms of action of prion protein fragment PrP(106-126) in rat basal forebrain neurons.

Science.gov (United States)

Alier, Kwai; Li, Zongming; Mactavish, David; Westaway, David; Jhamandas, Jack H

2010-08-01

Prion diseases are neurodegenerative disorders that are characterized by the presence of the misfolded prion protein (PrP). Neurotoxicity in these diseases may result from prion-induced modulation of ion channel function, changes in neuronal excitability, and consequent disruption of cellular homeostasis. We therefore examined PrP effects on a suite of potassium (K(+)) conductances that govern excitability of basal forebrain neurons. Our study examined the effects of a PrP fragment [PrP(106-126), 50 nM] on rat neurons using the patch clamp technique. In this paradigm, PrP(106-126) peptide, but not the "scrambled" sequence of PrP(106-126), evoked a reduction of whole-cell outward currents in a voltage range between -30 and +30 mV. Reduction of whole-cell outward currents was significantly attenuated in Ca(2+)-free external media and also in the presence of iberiotoxin, a blocker of calcium-activated potassium conductance. PrP(106-126) application also evoked a depression of the delayed rectifier (I(K)) and transient outward (I(A)) potassium currents. By using single cell RT-PCR, we identified the presence of two neuronal chemical phenotypes, GABAergic and cholinergic, in cells from which we recorded. Furthermore, cholinergic and GABAergic neurons were shown to express K(v)4.2 channels. Our data establish that the central region of PrP, defined by the PrP(106-126) peptide used at nanomolar concentrations, induces a reduction of specific K(+) channel conductances in basal forebrain neurons. These findings suggest novel links between PrP signalling partners inferred from genetic experiments, K(+) channels, and PrP-mediated neurotoxicity.

Response of PCB contamination in stream fish to abatement actions at an industrial site

International Nuclear Information System (INIS)

Southworth, G.R.; Peterson, M.J.; McCarthy, J.F.; Milne, G.

1995-01-01

The Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, used large quantities of PCBs in equipment associated with the great electric power requirements of isotopic enrichment of uranium. Historic losses of PCBs in the 1950s and 1960s have left a legacy of contamination at the site. A biological monitoring program implemented in 1987 found PCBs in PGDP effluents and in fish downstream from facility discharges. As a consequence, a fish consumption advisory was posted on Little Bayou Creek by the Commonwealth of Kentucky in 1987, and regulatory discharge limits for PCBs at PGDP were reduced. Monitoring at multiple locations in receiving streams indicated that PGDP discharges were more important than in stream sediment contamination as sources of PCBs to fish. Environmental management and compliance staff at PGDP led an effort to reduce PCB discharges and monitor the effects of those actions. The active discharge of uncontaminated process water to historically PCB-contaminated drainage systems was found to mobilize PCBs into KPDES (Clean Water Act) regulated effluents. Efforts to locate PCB sources within the plant, coupled with improvements in management practices and remedial actions, appear to have been successful in reducing PCB discharges from these sources. Actions included emplacing passive monitors in the plant drainage system to identify this as a chronic source, and consolidating and re-routing effluents to minimize flow through PCB-contaminated channels. As a consequence, PCB contamination in fish in small streams receiving plant discharges decreased 75% over from 1992--1995

A modeling approach to compare ΣPCB concentrations between congener-specific analyses

Science.gov (United States)

Gibson, Polly P.; Mills, Marc A.; Kraus, Johanna M.; Walters, David M.

2017-01-01

Changes in analytical methods over time pose problems for assessing long-term trends in environmental contamination by polychlorinated biphenyls (PCBs). Congener-specific analyses vary widely in the number and identity of the 209 distinct PCB chemical configurations (congeners) that are quantified, leading to inconsistencies among summed PCB concentrations (ΣPCB) reported by different studies. Here we present a modeling approach using linear regression to compare ΣPCB concentrations derived from different congener-specific analyses measuring different co-eluting groups. The approach can be used to develop a specific conversion model between any two sets of congener-specific analytical data from similar samples (similar matrix and geographic origin). We demonstrate the method by developing a conversion model for an example data set that includes data from two different analytical methods, a low resolution method quantifying 119 congeners and a high resolution method quantifying all 209 congeners. We used the model to show that the 119-congener set captured most (93%) of the total PCB concentration (i.e., Σ209PCB) in sediment and biological samples. ΣPCB concentrations estimated using the model closely matched measured values (mean relative percent difference = 9.6). General applications of the modeling approach include (a) generating comparable ΣPCB concentrations for samples that were analyzed for different congener sets; and (b) estimating the proportional contribution of different congener sets to ΣPCB. This approach may be especially valuable for enabling comparison of long-term remediation monitoring results even as analytical methods change over time. 

Estrogenicity and androgenicity screening of PCB sulfate monoesters in human breast cancer MCF-7 cells

OpenAIRE

Flor, Susanne; He, Xianran; Lehmler, Hans-Joachim; Ludewig, Gabriele

2015-01-01

Recent studies identified PCB sulfate esters as a major product of PCB metabolism. Since hydroxy-PCBs (HO-PCBs), the immediate precursors of PCB sulfates and important contributors to PCB toxicity, were shown to have estrogenic activity, we investigated the estrogenicity/androgenicty of a series of PCB sulfate metabolites. We synthesized the five possible structural sulfate monoester metabolites of PCB 3, a congener shown to be biotransformed to sulfates, a sulfate ester of the paint-specific...

Low consumption single-use microvalve for microfluidic PCB-based platforms

International Nuclear Information System (INIS)

Flores, G; Aracil, C; Perdigones, F; Quero, J M

2014-01-01

In this paper, a single-use and unidirectional microvalve with low consumption of energy for PCB-based microfluidic platforms is reported. Its activation is easy because it works as a fuse. The fabrication process of the device is based on PCB technology and a typical SU-8 process, using the PCB as a substrate and SU-8 for the microfluidic channels and chambers. The microvalve is intended to be used to impulse small volumes of fluids and it has been designed to be highly integrable in PCB-based microfluidic platforms. The proposed device has been fabricated, integrated and tested in a general purpose microfluidic circuit, resulting in a low activation time, of about 100 μs, and a low consumption of energy, with a maximum of 27 mJ. These results show a significant improvement because the energy consumption is about 84% lower and the time response is about four orders of magnitude shorter if compared with similar microvalves for impulsion of fluids on PCB-based platforms. (paper)

Chronic treatment with polychlorinated biphenyls (PCB) during pregnancy and lactation in the rat Part 2: Effects on reproductive parameters, on sex behavior, on memory retention and on hypothalamic expression of aromatase and 5alpha-reductases in the offspring.

Science.gov (United States)

Colciago, A; Casati, L; Mornati, O; Vergoni, A V; Santagostino, A; Celotti, F; Negri-Cesi, P

2009-08-15

The gender-specific expression pattern of aromatase and 5alpha-reductases (5alpha-R) during brain development provides neurons the right amount of estradiol and DHT to induce a dimorphic organization of the structure. Polychlorinated biphenyls (PCBs) are endocrine disruptive pollutants; exposure to PCBs through placental transfer and breast-feeding may adversely affect the organizational action of sex steroid, resulting in long-term alteration of reproductive neuroendocrinology. The study was aimed at: a) evaluating the hypothalamic expression of aromatase, 5alpha-R1 and 5alpha-R2 in fetuses (GD20), infant (PN12), weaning (PN21) and young adult (PN60) male and female rats exposed to PCBs during development; b) correlating these parameters with the time of testicular descent, puberty onset, estrous cyclicity and copulatory behavior; c) evaluating possible alterations of some non reproductive behaviors (locomotion, learning and memory, depression/anxiety behavior). A reconstituted mixture of four indicator congeners (PCB 126, 138, 153 and 180) was injected subcutaneously to dams at the dose of 10 mg/kg daily from GD15 to GD19 and then twice a week till weanling. The results indicated that developmental PCB exposure produced important changes in the dimorphic hypothalamic expression of both aromatase and the 5alpha-Rs, which were still evident in adult animals. We observed that female puberty onset occurs earlier than in control animals without cycle irregularity, while testicular descent in males was delayed. A slight but significant impairment of sexual behavior and an important alteration in memory retention were also noted specifically in males. We conclude that PCBs might affect the dimorphic neuroendocrine control of reproductive system and of other neurobiological processes.

Studies on the distribution of 14C-labelled PCB in the body, 4

International Nuclear Information System (INIS)

Nagao, Soshichi; Hosoya, Hideo

1976-01-01

This paper is a report of 14 C-PCB distribution series in animals. We reported the results of the distribution of 14 C-PCB from birds, fish and shell in the previous experiments, and we have obtained some results from present experiment. This time interperito neal injection of 14 C-PCB solution was carried to mice, and the results were as follows; Excretion of 14 C-PCB as radioactivity was at its maximum about 6 hr. after medication. Excretive ratio was 87.20% for 24 hr, but 72.43% of radioactivity was excreted within 12hr. The result of radiopaperchromatography showed that 14 C-PCB was not changeable in the fecus after medication, being Rf = 0.92 in comparison with standard 14 C-PCB. 14 C-PCB distributed throughout the body of mice in 24 hr. and at least remained over till 480 hr. in adipose tissues of mice after single medication. (auth.)

Sexual difference in PCB concentrations of walleyes (Sander vitreus) from a pristine lake

Science.gov (United States)

Madenjian, C.P.; Hanchin, P.A.; Chernyak, S.M.; Begnoche, L.J.

2009-01-01

We determined polychlorinated biphenyl (PCB) concentrations in 15 adult female walleyes (Sander vitreus) and 15 adult male walleyes from South Manistique Lake (Michigan, United States), a relatively pristine lake with no point source inputs of PCBs. By measuring PCB concentration in gonads and in somatic tissue of the South Manistique Lake fish, we also estimated the expected change in PCB concentration due to spawning for both sexes. To determine whether gross growth efficiency differed between the sexes, we applied bioenergetics modeling. Results showed that, on average, adult males were 34% higher in PCB concentration than adult females in South Manistique Lake. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 1% and 5% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in adult male walleyes. Bioenergetics modeling results indicated that the sexual difference in PCB concentrations of South Manistique Lake walleyes was attributable, at least in part, to a sexual difference in gross growth efficiency (GGE). Adult female GGE was estimated to be up to 17% greater than adult male GGE.

77 FR 13603 - Anniston PCB Superfund Site; Anniston, Calhoun County, AL; Correction

Science.gov (United States)

2012-03-07

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9644-2; CERCLA-04-2012-3763] Anniston PCB Superfund Site... FR 11533 (FRL-9637-7), EPA posted a Notice of Amended Settlement concerning the Anniston PCB... the settlement are available from Ms. Paula V. Painter. Submit your comments by Site name Anniston PCB...

Chemical and microbiological characterization of an aged PCB-contaminated soil.

Science.gov (United States)

Stella, T; Covino, S; Burianová, E; Filipová, A; Křesinová, Z; Voříšková, J; Větrovský, T; Baldrian, P; Cajthaml, T

2015-11-15

This study was aimed at complex characterization of three soil samples (bulk soil, topsoil and rhizosphere soil) from a site historically contaminated with polychlorinated biphenyls (PCB). The bulk soil was the most highly contaminated, with a PCB concentration of 705.95 mg kg(-1), while the rhizosphere soil was the least contaminated (169.36 mg kg(-1)). PCB degradation intermediates, namely chlorobenzoic acids (CBAs), were detected in all the soil samples, suggesting the occurrence of microbial transformation processes over time. The higher content of organic carbon in the topsoil and rhizosphere soil than in the bulk soil could be linked to the reduced bioaccessibility (bioavailability) of these chlorinated pollutants. However, different proportions of the PCB congener contents and different bioaccessibility of the PCB homologues indicate microbial biotransformation of the compounds. The higher content of organic carbon probably also promoted the growth of microorganisms, as revealed by phospholipid fatty acid (PFLA) quantification. Tag-encoded pyrosequencing analysis showed that the bacterial community structure was significantly similar among the three soils and was predominated by Proteobacteria (44-48%) in all cases. Moreover, analysis at lower taxonomic levels pointed to the presence of genera (Sphingomonas, Bulkholderia, Arthrobacter, Bacillus) including members with reported PCB removal abilities. The fungal community was mostly represented by Basidiomycota and Ascomycota, which accounted for >80% of all the sequences detected in the three soils. Fungal taxa with biodegradation potential (Paxillus, Cryptococcus, Phoma, Mortierella) were also found. These results highlight the potential of the indigenous consortia present at the site as a starting point for PCB bioremediation processes. Copyright © 2015 Elsevier B.V. All rights reserved.

Experimental feeding of DDE and PCB to female big brown bats (Eptesicus fuscus)

Science.gov (United States)

Clark, D.R.; Prouty, R.M.

1977-01-01

Twenty-two female big brown bats (Eptesicus fuscus) were collected in a house attic in Montgomery County, Maryland. Seventeen were fed mealworms (Tenebrio molitor larvae) that contained 166 ppm DDE; the other five were fed uncontaminated mealworms. After 54 days of feeding, six dosed bats were frozen and the remaining 16 were starved to death. In a second experiment, 21 female big brown bats were collected in a house attic in Prince Georges County, Maryland. Sixteen were fed mealworms that contained 9.4 ppm Aroclor 1254 (PCB). After 37 days, two bats had died, four dosed bats were frozen, and the remaining 15 were starved to death. Starvation caused mobilization of stored residues. After the feeding periods, average weights of all four groups (DDE-dosed, DDE control, PCB-dosed, PCB control) had increased. However, weights of DDE-dosed bats had increased significantly more than those of their contols, whereas weights of PCB-dosed bats had increased significantly less than those of their controls. During starvation, PCB-dosed bats lost weight significantly more slowly than controls. Because PCB levels in dosed bats resembled levels found in some free-living big brown bats, PCBs may be slowing metabolic rates of some free-living bats. It is not known how various common organochlorine residues may affect metabolism in hibernating bats. DDE and PCB increased in brains of starving bats as carcass fat was metabolized. Because the tremors and/or convulsions characteristic of neurotoxicity were not observed, we think even the maximum brain levels attained (132 ppm DDE, 20 ppm PCB) were sublethal. However, extrapolation of our DDE data predicted lethal brain levels when fat reserves declined sufficiently. PCB-dosed bats were probably in no danger of neurotoxic poisoning. However, PCB can kill by a nonneurotoxic mode, and this could explain the deaths of two bats on PCB dosage.

Differential neurotoxic effects of in utero and lactational exposure to hydroxylated polychlorinated biphenyl (OH-PCB 106) on spontaneous locomotor activity and motor coordination in young adult male mice.

Science.gov (United States)

Haijima, Asahi; Lesmana, Ronny; Shimokawa, Noriaki; Amano, Izuki; Takatsuru, Yusuke; Koibuchi, Noriyuki

2017-01-01

We investigated whether in utero or lactational exposure to 4-hydroxy-2',3,3',4',5'-pentachlorobiphenyl (OH-PCB 106) affects spontaneous locomotor activity and motor coordination in young adult male mice. For in utero exposure, pregnant C57BL/6J mice received 0.05 or 0.5 mg/kg body weight of OH-PCB 106 or corn oil vehicle via gavage every second day from gestational day 10 to 18. For lactational exposure, the different groups of dams received 0.05 or 0.5 mg/kg body weight of OH-PCB 106 or corn oil vehicle via gavage every second day from postpartum day 3 to 13. At 6-7 weeks of age, the spontaneous locomotor activities of male offspring were evaluated for a 24-hr continuous session in a home cage and in an open field for 30-min. Motor coordination function on an accelerating rotarod was also measured. Mice exposed prenatally to OH-PCB 106 showed increased spontaneous locomotor activities during the dark phase in the home cage and during the first 10-min in the open field compared with control mice. Mice exposed lactationally to OH-PCB 106, however, did not show a time-dependent decrease in locomotor activity in the open field. Instead, their locomotor activity increased significantly during the second 10-min block. In addition, mice exposed lactationally to OH-PCB 106 displayed impairments in motor coordination in the rotarod test. These results suggest that perinatal exposure to OH-PCB 106 affects motor behaviors in young adult male mice. Depending on the period of exposure, OH-PCB 106 may have different effects on neurobehavioral development.

PCB usage at the Grand Junction Area Office Facility. Final report

International Nuclear Information System (INIS)

Miller, M.E.; Donivan, S.

1982-06-01

The development, implementation, and results of the polychlorinated biphenyl (PCB) identification project at the Grand Junction Area Office (GJAO) are summarized. Methodology for the PCB analysis is described, and results are tabulated. Of the 51 transformers and disconnects in use at GJAO, 15 unites were determined to be PCB-contaminated or filled with PCBs. This number falls within EPA's estimate of 25 to 40 percent of all transformers in use being at least contaminated. Approximately 324 gallons of PCBs and 515 gallons of PCB-contaminated fluids are being used currently. No contaminated transformers or disconnects are in a position to contaminate food or feed products at the facility

New technologies for PCB [polychlorinated biphenyl] decontamination

International Nuclear Information System (INIS)

Webber, I.

1993-01-01

Polychlorinated biphenyls (PCB) were mixed with chlorobenzenes to reduce viscosity and provide for both electrical insulation and convective heat transfers. These mixtures were known as askarels, and ca 99.8% of PCBs used in electrical applications are contained in askarel-filled transformers and capacitors. It is estimated that there are ca 180 million gal of PCB-contaminated oil distributed through over 3 million transformers in the USA. Technology used for decontaminating these transformers depends on the concentration of the PCB contamination. At low PCB concentrations of up to ca 2,000 ppM, chemical methods can be used; at higher concentrations, alternative disposal options become more attractive. For chemical treatment, a small mobile unit using quick-reacting reagents has been developed for on-site decontamination. For highly contaminated transformers, retrofilling is very attractive since the owner's liability is minimized at minimum cost. Conventional flush/drain procedures have such drawbacks as the inability to remove oil trapped in windings and the leaching of trapped PCBs back into the uncontaminated retrofill oil over time. A new process has been developed to solve the leaching problem and to decontaminate the drained askarel at room temperature using a catalyst. An alternative disposal strategy involves dismantling the transformer carcass, incinerating non-recyclable materials, and cleaning the metals and wire with solvent. 8 figs

40 CFR 261.8 - PCB wastes regulated under Toxic Substance Control Act.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false PCB wastes regulated under Toxic... (CONTINUED) SOLID WASTES (CONTINUED) IDENTIFICATION AND LISTING OF HAZARDOUS WASTE General § 261.8 PCB wastes regulated under Toxic Substance Control Act. The disposal of PCB-containing dielectric fluid and electric...

Importance of growth rate on Hg and PCB bioaccumulation in fish

Science.gov (United States)

Li, Jiajia; Haffner, G. Douglas; Patterson, Gordon; Walters, David M.; Burtnyk, Michael D.; Drouillard, Ken G.

2018-01-01

To evaluate the effect of fish growth on mercury (Hg) and polychlorinated biphenyls (PCBs) bioaccumulation, a non‐steady state toxicokinetic model, combined with a Wisconsin bioenergetics model, was developed to simulate Hg and PCB bioaccumulation in Bluegill (Lepomis macrochirus). The model was validated by comparing observed versus predicted Hg and PCB 180 concentrations across 5 age classes from five different waterbodies across North America. The non‐steady state model generated accurate predictions for Hg and PCB bioaccumulation in three of five waterbodies: Apsey, Sharbot and Stonelick Lake. The poor performance of the model for the Detroit River and Lake Hartwell, which were two well‐known contaminated sites with possibly high heterogeneity in spatial contamination, was attributed to changes in the feeding behavior and/ or change in prey contamination. Model simulations indicate that growth dilution is a major component of contaminant bioaccumulation patterns in fish especially during early life stages and was predicted to be more important for hydrophobic PCBs compared to Hg. Simulations which considered tissue specific growth provided some improvement in model performance particularly for PCBs in fish populations which exhibited changes in their whole body lipid content with age. Higher variation in lipid growth compared with that of lean dry protein was also observed between different bluegill populations which partially explains the greater variation in PCB bioaccumulation slopes compared with Hg across sampling sites.

Machine Vision Implementation in Rapid PCB Prototyping

Directory of Open Access Journals (Sweden)

Yosafat Surya Murijanto

2012-03-01

Full Text Available Image processing, the heart of machine vision, has proven itself to be an essential part of the industries today. Its application has opened new doorways, making more concepts in manufacturing processes viable. This paper presents an application of machine vision in designing a module with the ability to extract drills and route coordinates from an un-mounted or mounted printed circuit board (PCB. The algorithm comprises pre-capturing processes, image segmentation and filtering, edge and contour detection, coordinate extraction, and G-code creation. OpenCV libraries and Qt IDE are the main tools used. Throughout some testing and experiments, it is concluded that the algorithm is able to deliver acceptable results. The drilling and routing coordinate extraction algorithm can extract in average 90% and 82% of the whole drills and routes available on the scanned PCB in a total processing time of less than 3 seconds. This is achievable through proper lighting condition, good PCB surface condition and good webcam quality. 

Remediation of PCB-contaminated soils. Risk analysis of biological in situ processes

Energy Technology Data Exchange (ETDEWEB)

Rein, Arno

2006-12-08

Biological in situ measures can be efficient and cost effective options for the remediation of contaminated sites. However, the accepted application requires a detailed and reliable analysis of potential impacts. An important objective is to quantify the potential of contaminant degradation and metabolite formation. This thesis addresses a quantitative multimedia risk assessment. Methodologies and tools were developed for this objective and applied to evaluate in situ bioremediation of soils contaminated with polychlorinated biphenyls (PCBs). Soil bacteria in conjunction with plant roots were addressed (rhizoremediation) with a focus on the use of genetically modified microorganisms (GMOs). PCBs are known to be harmful compounds that are ubiquitously distributed in the environment. PCB contaminations in soil and groundwater were identified as important problems. 209 different congeners are sterically possible, but not all are of environmental significance. PCB congeners of concern were evaluated with respect to their potential toxicity, environmental occurrence and mobility. For this objective, congener specific data on the toxicity potential and the frequency in environmental matrices were collected. To quantify the mobility potential, multimedia modelling was performed applying deterministic and probabilistic procedures. 56 PCB congeners of concern were evaluated, and multimedia risk assessments of PCB-contaminated soils should concentrate on this group. Kinetics parameters were specified for degradation experiments with individual PCB congeners in solution and different bacterial strains. These laboratory assays were performed with wild-type Burkholderia sp. strain LB400 and the genetically modified Pseudomonas fluorescens strains F113pcb and F113L::1180. The F113 derivatives demonstrated a good survival ability in willow (Salix sp.) rhizosphere (mesocosm experiments). Therefore, and due to high depletion rates, rhizoremediation with F113L::1180 and willow

PCB management at Manitoba Hydro's Waverley Service Centre

International Nuclear Information System (INIS)

Rempel, R.G.; Engstrom, T.

1996-01-01

Manitoba Hydro was the first Canadian utility to initiate a program to decontaminate insulating oil contaminated with polychlorinated biphenyls (PCBs). This paper describes Manitoba Hydro's recovery, reuse and recycling program, operated out of the utility's Waverley Service Centre (WSC). The WSC is a central facility serving to phase out and and destroy PCBs which remain in Manitoba Hydro's electrical system. Several hundred thousand litres of PCB-contaminated insulating oil are decontaminated annually at the WSC. The decontaminated oil is then reconditioned for reuse within the system operations. A PCBX unit was purchased from Sun Ohio for the decontamination of insulating oils containing PCBs. PCB decontamination is achieved through a chemical dechlorination treatment process. The PCBX treatment unit and the PCB storage building were described. 18 refs., 8 figs

Fast and parallel determination of PCB 77 and PCB 180 in plasma using ultra performance liquid chromatography with diode array detection: A pharmacokinetic study in Swiss albino mouse.

Science.gov (United States)

Ramanujam, N; Sivaselvakumar, M; Ramalingam, S

2017-11-01

A simple, sensitive and reproducible ultra-performance liquid chromatography (UPLC) method has been developed and validated for simultaneous estimation of polychlorinated biphenyl (PCB) 77 and PCB 180 in mouse plasma. The sample preparation was performed by simple liquid-liquid extraction technique. The analytes were chromatographed on a Waters Acquity H class UPLC system using isocratic mobile phase conditions at a flow rate of 0.3 mL/min and Acquity UPLC BEH shield RP 18 column maintained at 35°C. Quantification was performed on a photodiode array detector set at 215 nm and PCB 101 was used as internal standard (IS). PCB 77, PCB 180, and IS retention times were 2.6, 4.7 and 2.8 min, respectively, and the total run time was 6 min. The method was validated for specificity, selectivity, recovery, linearity, accuracy, precision and sample stability. The calibration curve was linear over the concentration range 10-3000 ng/mL for PCB 77 and PCB 180. Intra- and inter-day precisions for PCBs 77 and 180 were found to be good with CV <4.64%, and the accuracy ranged from 98.90 to 102.33% in mouse plasma. The validated UPLC method was successfully applied to the pharmacokinetic study of PCBs 77 and 180 in mouse plasma. Copyright © 2017 John Wiley & Sons, Ltd.

40 CFR 761.2 - PCB concentration assumptions for use.

Science.gov (United States)

2010-07-01

... dielectric fluid are unknown, any person must assume the transformer to be a PCB Transformer. (4) Any person must assume that a capacitor manufactured prior to July 2, 1979, whose PCB concentration is not established contains ≥500 ppm PCBs. Any person may assume that a capacitor manufactured after July 2, 1979, is...

Reliability of lead-free solder joints with different PCB surface finishes under thermal cycling

Energy Technology Data Exchange (ETDEWEB)

Xia Yanghua [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)], E-mail: xia_yanghua@hotmail.com; Xie Xiaoming [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

2008-04-24

The reliability of lead-free electronic assemblies under thermal cycling was investigated. Thin small outline package (TSOP) devices with FeNi leads were reflow soldered on FR4 PCB (printed circuit board) with Sn3.0Ag0.5Cu (wt%) solder. The effects of different PCB finishes (organic solderability preservative (OSP) and electroless nickel immersion gold (ENIG)) were studied. The results show that OSP finish reveals better performance than its ENIG counterparts. The crack originates at the fringe of heel fillet in both cases. The propagation of crack in the ENIG case is along the device/solder interface, while in the case of OSP, the crack extends parallel to the solder/PCB interface. When the OSP finishes are employed, many Cu6Sn5 precipitates form inside the bulk solder and have a strengthening effect on the solder joint, resulting in better reliability performance as compared to those with ENIG finishes.

Integrated Nanozero Valent Iron and Biosurfactant-Aided Remediation of PCB-Contaminated Soil

Directory of Open Access Journals (Sweden)

He Zhang

2016-01-01

Full Text Available Polychlorobiphenyls (PCBs have been identified as environmental hazards for years. Due to historical issues, a considerable amount of PCBs was released deep underground in Canada. In this research, a nanoscale zero valent iron- (nZVI- aided dechlorination followed by biosurfactant enhanced soil washing method was developed to remove PCBs from soil. During nZVI-aided dechlorination, the effects of nZVI dosage, initial pH level, and temperature were evaluated, respectively. Five levels of nZVI dosage and two levels of initial pH were experimented to evaluate the PCB dechlorination rate. Additionally, the temperature changes could positively influence the dechlorination process. In soil washing, the presence of nanoiron particles played a key role in PCB removal. The crude biosurfactant was produced using a bacterial stain isolated from the Atlantic Ocean and was applied for soil washing. The study has led to a promising technology for PCB-contaminated soil remediation.

Evaluation of PCB sources and releases for identifying priorities to reduce PCBs in Washington State (USA).

Science.gov (United States)

Davies, Holly; Delistraty, Damon

2016-02-01

Polychlorinated biphenyls (PCBs) are ubiquitously distributed in the environment and produce multiple adverse effects in humans and wildlife. As a result, the purpose of our study was to characterize PCB sources in anthropogenic materials and releases to the environment in Washington State (USA) in order to formulate recommendations to reduce PCB exposures. Methods included review of relevant publications (e.g., open literature, industry studies and reports, federal and state government databases), scaling of PCB sources from national or county estimates to state estimates, and communication with industry associations and private and public utilities. Recognizing high associated uncertainty due to incomplete data, we strived to provide central tendency estimates for PCB sources. In terms of mass (high to low), PCB sources include lamp ballasts, caulk, small capacitors, large capacitors, and transformers. For perspective, these sources (200,000-500,000 kg) overwhelm PCBs estimated to reside in the Puget Sound ecosystem (1500 kg). Annual releases of PCBs to the environment (high to low) are attributed to lamp ballasts (400-1500 kg), inadvertent generation by industrial processes (900 kg), caulk (160 kg), small capacitors (3-150 kg), large capacitors (10-80 kg), pigments and dyes (0.02-31 kg), and transformers (PCB distribution and decrease exposures include assessment of PCBs in buildings (e.g., schools) and replacement of these materials, development of Best Management Practices (BMPs) to contain PCBs, reduction of inadvertent generation of PCBs in consumer products, expansion of environmental monitoring and public education, and research to identify specific PCB congener profiles in human tissues.

20 CFR 498.126 - Settlement.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Settlement. 498.126 Section 498.126 Employees' Benefits SOCIAL SECURITY ADMINISTRATION CIVIL MONETARY PENALTIES, ASSESSMENTS AND RECOMMENDED EXCLUSIONS § 498.126 Settlement. The Inspector General has exclusive authority to settle any issues or case...

Polychlorinated biphenyl (PCB) induction of CYP3A4 enzyme activity in healthy Faroese adults

International Nuclear Information System (INIS)

Petersen, Maria Skaalum; Halling, Jonrit; Damkier, Per; Nielsen, Flemming; Grandjean, Philippe; Weihe, Pal; Brosen, Kim

2007-01-01

The CYP3A4 enzyme is, along with other cytochrome P450 enzymes, involved in the metabolism of environmental pollutants and is highly inducible by these substances. A commercial polychlorinated biphenyl (PCB) mixture, 1,1,1,-trichloro-2-(o-chlorophenyl), 2-(p'-chlorophenyl)ethane (o,p'-DDT) and 1,1,-dichloro-2,2-bis (p-chlorophenyl)ethene (p,p'-DDE) are known to induce CYP3A4 activity through activation of nuclear receptors, such as the pregnane X receptor. However, this induction of CYP3A4 has not yet been investigated in humans. Thus, the aim of the study was to determine the variability of the CYP3A4 phenotype in regard to increased concentrations of PCBs and other persistent organohalogen pollutants (POPs) in healthy Faroese adults. In 310 randomly selected Faroese residents aged 18-60 years, the CYP3A4 activity was determined based on the urinary 6β-hydroxycortisol/cortisol (6β-OHC/FC) ratio. POP exposures were assessed by measuring their concentrations in serum lipid. The results showed a unimodal distribution of the 6β-OHC/FC ratio with values ranging from 0.58 to 27.38. Women had a slightly higher 6β-OHC/FC ratio than men (p = 0.07). Confounder-adjusted multiple regression analysis showed significant associations between 6β-OHC/FC ratios and ΣPCB, PCB-TEQ and p,p'-DDE, o,p'-DDT and HCB, respectively, but the associations were statistically significant for men only

Uptake of dietary PCB by pregnant big brown bats (Eptesicus fuscus) and their fetuses

Science.gov (United States)

Clark, D.R.

1978-01-01

In a previous study (CLARK and LAMONT 1976), 26 pregnant big brown bats were captured, caged, and fed uncontaminated mealworms until their litters were born. Immediately after parturition, female bats and litters were frozen. Five litters included at least one dead young, and these five litters contained significantly more of the PCB, Aroclor 1260, than did the 21 litters with only living young....The present study attempted to verify that Aroclor 1260 could cause stillbirths. I fed 18 of 36 pregnant big brown bats mealworms containing 6.36 ppm of Aroclor 1260 prior to birth of their litters. Both carcasses and litters of dosed females contained approximately 10 times more PCB than their respective controls, but no additional stillbirths resulted. Three of 18 control litters included dead young, whereas the comparable ratio among litters from dosed females was one of 18. Additional comparisons involving means of litter weight, adult female weight, parturition date, days in captivity, tooth wear, and percentage fat also failed to show any effect of the PCB....The association found earlier between PCB and dead young (CLARK and LAMONT 1976) was not one of cause and effect. In both studies, bats that had not been dosed showed greater PCB residues among younger females. Among control bats in the present series, females that produced dead young were significantly younger (that is, showed significantly less tooth wear) than other females. In sum, whereas dead young seemed to have been caused by greater residues, these two factors were actually independent of each other but associated with a third factor--age of the female parent bat.

Study of penetration behavior of PCB-DNAPL in a sand layer by a column experiment.

Science.gov (United States)

Okuda, Nobuyasu; Shimizu, Takaaki; Muratani, Masaru; Terada, Akihiko; Hosomi, Masaaki

2014-11-01

To better understand the infiltration performances of high concentration PCB oils (KC-300 and KC-1000 polychlorinated biphenyl (PCB) mixtures), representative dense non-aqueous phase liquid (DNAPL), under both saturated and unsaturated conditions, we conducted experiments on a sand column filled with Toyoura Standard Sand. When PCB oil with the volume comparable to the total porosity in the column was supplied, the residual PCB concentrations under PCB-water conditions were 4.9×10(4)mgkg(-1) in KC-300 and 3.9×10(4)mgkg(-1) in KC-1000. Under PCB-air conditions, residual PCB concentrations were 6.0×10(4)mgkg(-1) and 2.4×10(5)mgkg(-1) in the upper and lower parts for KC-300 and 3.6×10(4)mgkg(-1) and 1.5×10(5)mgkg(-1) in those for KC-1000, respectively, while the rest of the PCBs were infiltrated. On the other hand, when a small amount of PCB oil with the volume far smaller than the total porosity in the column was supplied, the original PCBs were not transported via water permeation. However, lower-chlorinated PCB congeners-e.g., di- or tri-chlorinated biphenyls-preferentially dissolved and were infiltrated from the bottom of the column. These propensities on PCB oil infiltration can be explained in conjunction with the degree of PCB saturation in the sand column. Copyright © 2014 Elsevier Ltd. All rights reserved.

Tracking Polychlorinated Biphenyls (PCB) after an incident along a river system - Case study Elbe River

Science.gov (United States)

Kleisinger, Carmen; Dietrich, Stephan; Kehl, Nora; Claus, Evelyn; Schubert, Birgit

2017-04-01

In spring 2015, extremely high concentrations of Polychlorinated Biphenyls (PCB) well above the long-term average were detected in suspended particulate matter (SPM) within the River Elbe. They were released due to abrasive blasting of the old coating from a bridge in the upper part of the River, approximately 50 km upstream of the first measurement site. PCBs are persistent organic pollutants, preferentially bound to fine-grained fractions of the SPM. Results from monitoring of contaminants in SPM along the Elbe indicate the further dispersal of the PCB-contaminated sediments. These measurements include yearly investigations on PCB concentrations in sediments in the inner reaches of the Elbe, an additional longitudinal survey in 2015 and monthly monitoring of PCBs in SPM at stations along the river including the Elbe estuary (Germany). The Elbe estuary is of major economic importance since Hamburg harbour, one of the largest harbours in Europe, is located there. Maintaining the harbour includes dredging and, i.a., relocating large amounts of the dredged material within the water body. High PCB concentrations in sediments could lead to restrictions on the relocation of these sediments. This study aims at tracking the fate of PCB contaminated material released from the point source of the incident site along the whole river stretch and at estimating its impact on the quality of sediments and consequently on dredging activities in the estuary. The ratio of high (PCB 138, 152 and 180) versus low (PCB 28, 52, 101) chlorinated PCB congeners proved to be a suitable tracer to distinguish the PCB load released by the incident from the long-term background signals. As Delor 106/Clophen A60, which contains approx. 90% hexa- to decachloric congeners, was an additive in the coating of the bridge, the pattern of PCBs released by the incident is dominated by the highly chlorinated PCB-congeners PCB 138, 153 and 180. At the tidal weir Geesthacht, the entrance to the estuary, an

42 CFR 1003.126 - Settlement.

Science.gov (United States)

2010-10-01

... 42 Public Health 5 2010-10-01 2010-10-01 false Settlement. 1003.126 Section 1003.126 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES CIVIL MONEY PENALTIES, ASSESSMENTS AND EXCLUSIONS § 1003.126 Settlement. The Inspector General has exclusive...

Developmental PCB Exposure Increases Audiogenic Seizures and Decreases Glutamic Acid Decarboxylase in the Inferior Colliculus.

Science.gov (United States)

Bandara, Suren B; Eubig, Paul A; Sadowski, Renee N; Schantz, Susan L

2016-02-01

Previously, we observed that developmental polychlorinated biphenyl (PCB) exposure resulted in an increase in audiogenic seizures (AGSs) in rats. However, the rats were exposed to loud noise in adulthood, and were not tested for AGS until after 1 year of age, either of which could have interacted with early PCB exposure to increase AGS susceptibility. This study assessed susceptibility to AGS in young adult rats following developmental PCB exposure alone (without loud noise exposure) and investigated whether there was a decrease in GABA inhibitory neurotransmission in the inferior colliculus (IC) that could potentially explain this effect. Female Long-Evans rats were dosed orally with 0 or 6 mg/kg/day of an environmentally relevant PCB mixture from 28 days prior to breeding until the pups were weaned at postnatal day 21. One male-female pair from each litter was retained for the AGS study whilst another was retained for Western blot analysis of glutamic acid decarboxylase (GAD) and GABAAα1 receptor in the IC, the site in the auditory midbrain where AGS are initiated. There was a significant increase in the number and severity of AGSs in the PCB groups, with females somewhat more affected than males. GAD65 was decreased but there was no change in GAD67 or GABAAα1 in the IC indicating decreased inhibitory regulation in the PCB group. These results confirm that developmental PCB exposure alone is sufficient to increase susceptibility to AGS, and provide the first evidence for a possible mechanism of action at the level of the IC. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Species and Sex Differences in the Morphogenic Response of Primary Rodent Neurons to 3,3'-Dichlorobiphenyl (PCB 11).

Science.gov (United States)

Sethi, Sunjay; Keil, Kimberly P; Lein, Pamela J

2017-12-23

PCB 11 is an emerging global pollutant that we recently showed promotes axonal and dendritic growth in primary rat neuronal cell cultures. Here, we address the influence of sex and species on neuronal responses to PCB 11. Neuronal morphology was quantified in sex-specific primary hippocampal and cortical neuron-glia co-cultures derived from neonatal C57BL/6J mice and Sprague Dawley rats exposed for 48 h to vehicle (0.1% DMSO) or PCB 11 at concentrations ranging from 1 fM to 1 nM. Total axonal length was quantified in tau-1 immunoreactive neurons at day in vitro (DIV) 2; dendritic arborization was assessed by Sholl analysis at DIV 9 in neurons transfected with MAP2B-FusRed. In mouse cultures, PCB 11 enhanced dendritic arborization in female, but not male, hippocampal neurons and male, but not female, cortical neurons. In rat cultures, PCB 11 promoted dendritic arborization in male and female hippocampal and cortical neurons. PCB 11 also increased axonal growth in mouse and rat neurons of both sexes and neuronal cell types. These data demonstrate that PCB 11 exerts sex-specific effects on neuronal morphogenesis that vary depending on species, neurite type, and neuronal cell type. These findings have significant implications for risk assessment of this emerging developmental neurotoxicant.

Mercury accumulation and the mercury-PCB-sex interaction in summer flounder

Science.gov (United States)

Madenjian, Charles P.; Jensen, Olaf P.; Krabbenhoft, David P.; DeWild, John F.; Ogorek, Jacob M.; Vastano, Anthony R.

2016-01-01

Patterns in the relative differences in contaminant concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish total mercury (Hg) concentrations in 23 female summer flounder (Paralichthys dentatus) and 27 male summer flounder from New Jersey coastal waters. To estimate the change in Hg concentration due to release of eggs at spawning, Hg concentration in the somatic tissue and ovaries of 5 of the 23 female summer flounder were also determined. To ascertain whether most of the Hg in the summer flounder was methylmercury (MeHg), whole-fish MeHg concentrations were determined in all 50 summer flounder. Whole-fish Hg concentrations averaged 113 ng/g for females and 111 ng/g for males. Thus, females were 2% higher in Hg concentration than males, on average, but the difference was not statistically significant. Based on Hg determinations in the somatic tissue and ovaries, we predicted that Hg concentration of females would increase by 3.6%, on average, immediately after spawning due to release of eggs. On average, 92% of the Hg in the summer flounder was MeHg. To determine whether the effect of sex on Hg concentration was significantly different from the effect of sex on polychlorinated biphenyl (PCB) concentration, we paired our Hg determinations with PCB determinations from a previous study, and applied regression analysis. Sex significantly interacted with contaminant type (Hg or PCBs), as males were 43% higher in PCB concentration than females, whereas females were 2% higher in Hg concentration than males. Males eliminating Hg from their bodies at a faster rate than females was a likely explanation for this discrepancy between the two contaminant types. Overall, the Hg and PCB concentrations in the summer flounder were relatively low, and therefore our findings also had implications for continued operation of the summer flounder fishery.

PCB contamination and effects on benthic invertebrate communities at the Irving Whale salvage site

National Research Council Canada - National Science Library

Ernst, W

2000-01-01

... patterns of polychlorinated biphenyl (PCB) contamination. In addition, snow crab tissue sampling, toxicity testing of sediments as well as analysis of the integrity of benthic biological communities was conducted around the Irving Whale footprint...

Effects of Anthropogenic Pollution on the Oxidative Phosphorylation Pathway of Hepatocytes from Natural Populations of Fundulus heteroclitus

Energy Technology Data Exchange (ETDEWEB)

Du, Xiao; Crawford, Douglas L.; Oleksiak, Marjorie F., E-mail: moleksiak@rsmas.miami.edu

2015-08-15

Highlights: • Fish from a highly polluted and clean reference population were compared. • Oxidative phosphorylation (e.g., State 3, enzymes, and proton LEAK) was quantified. • Polluted fish had lower LEAK, enzyme III and enzyme IV but higher enzyme I. • Exposures to PAH and PCB only affected individuals from the reference population. - Abstract: Persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), potentially target mitochondria and cause toxicity. We compared the effects of POPs on mitochondrial respiration by measuring oxidative phosphorylation (OxPhos) metabolism in hepatocytes isolated from lab-depurated Fundulus heteroclitus from a Superfund site contaminated with PAHs (Elizabeth River VA, USA) relative to OxPhos metabolism in individuals from a relatively clean, reference population (King’s Creek VA, USA). In individuals from the polluted Elizabeth River population, OxPhos metabolism displayed lower LEAK and lower activities in complex III, complex IV, and E State, but higher activity in complex I compared to individuals from the reference King’s Creek population. To test the supposition that these differences were due to or related to the chronic PAH contamination history of the Elizabeth River population, we compared the OxPhos functions of undosed individuals from the polluted and reference populations to individuals from these populations dosed with a PAH {benzo [α] pyrene (BaP)} or a PCB {PCB126 (3,3′,4,4′,5-pentachlorobiphenyl)}, respectively. Exposure to PAH or PCB affected OxPhos in the reference King’s Creek population but had no detectable effects on the polluted Elizabeth River population. Thus, PAH exposure significantly increased LEAK, and exposure to PCB126 significantly decreased State 3, E state and complex I activity in the reference King’s Creek population. These data strongly implicate an evolved tolerance in the Elizabeth River fish where dosed

Effects of Anthropogenic Pollution on the Oxidative Phosphorylation Pathway of Hepatocytes from Natural Populations of Fundulus heteroclitus

International Nuclear Information System (INIS)

Du, Xiao; Crawford, Douglas L.; Oleksiak, Marjorie F.

2015-01-01

Highlights: • Fish from a highly polluted and clean reference population were compared. • Oxidative phosphorylation (e.g., State 3, enzymes, and proton LEAK) was quantified. • Polluted fish had lower LEAK, enzyme III and enzyme IV but higher enzyme I. • Exposures to PAH and PCB only affected individuals from the reference population. - Abstract: Persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), potentially target mitochondria and cause toxicity. We compared the effects of POPs on mitochondrial respiration by measuring oxidative phosphorylation (OxPhos) metabolism in hepatocytes isolated from lab-depurated Fundulus heteroclitus from a Superfund site contaminated with PAHs (Elizabeth River VA, USA) relative to OxPhos metabolism in individuals from a relatively clean, reference population (King’s Creek VA, USA). In individuals from the polluted Elizabeth River population, OxPhos metabolism displayed lower LEAK and lower activities in complex III, complex IV, and E State, but higher activity in complex I compared to individuals from the reference King’s Creek population. To test the supposition that these differences were due to or related to the chronic PAH contamination history of the Elizabeth River population, we compared the OxPhos functions of undosed individuals from the polluted and reference populations to individuals from these populations dosed with a PAH {benzo [α] pyrene (BaP)} or a PCB {PCB126 (3,3′,4,4′,5-pentachlorobiphenyl)}, respectively. Exposure to PAH or PCB affected OxPhos in the reference King’s Creek population but had no detectable effects on the polluted Elizabeth River population. Thus, PAH exposure significantly increased LEAK, and exposure to PCB126 significantly decreased State 3, E state and complex I activity in the reference King’s Creek population. These data strongly implicate an evolved tolerance in the Elizabeth River fish where dosed

Removal of PCB from indoor air and surface materials by introduction of additional sorbing materials

DEFF Research Database (Denmark)

Gunnarsen, Lars Bo; Lyng, Nadja; Kolarik, Barbara

2017-01-01

Alleviation of indoor PCB contamination is extremely expensive because PCB from old primary sources has redistributed to most other surfaces over time. This study investigates the introduction of new removable sorbing materials as a method instantly lowering the concentration of PCB in indoor air...... and slowly decontaminating old surface materials. In three bedrooms of a contaminated apartment respectively new painted gypsum boards, sheets of flexible polyurethane foam and activated carbon fabric were introduced. The PCB concentrations in room air were monitored before the intervention and several times...... during the following 10 months. The PCB concentrations in the old surface materials as well as the new materials were also measured. An immediate reduction of PCB concentration in indoor air, a gradual increase of PCB in new material and as well a gradual reduction in old surface materials were...

Development of planar CT system for multi-layer PCB inspection

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Ho; Youn, Hanbean; Kam, Soohwa; Park, Eunpyeong; Kim, Ho Kyung [Pusan National University, Busan (Korea, Republic of)

2015-05-15

X-ray defect inspection apparatus can be used in the production line to inspect the PCB. However, a simple X-ray radiography cannot discriminate defects from the multi-layer PCBs because the layers of them overlays the defects. To complement this issue, computed tomography (CT) technology is applied to the NDT system which can offer 3-dimensional information of object. However, CT requires hundreds of projection images to examine a single PCB, hence real-time inspection is nearly impossible. In this study, we develop a planar computed tomography (pCT) system appropriate for the multi-layer PCB inspection. For the image reconstruction of planar cross-section images, we use the digital tomosynthesis (DTS) concept in association with the limited angle scanning. and performance characterization of the pCT system for the PCB inspection. The 3-d Fourier characteristics and more quantitative performance, such as contrast, uniformity, depth resolution will be presented. The cross-sectional images of multi-layer PCBs will also be demonstrated.

46 CFR 126.130 - Cranes.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Cranes. 126.130 Section 126.130 Shipping COAST GUARD... § 126.130 Cranes. (a) Except as provided by paragraph (b) of this section, cranes, if installed, must... chapter. (b) The manufacturer of a crane may have tests and inspections conducted in compliance with § 107...

33 CFR 157.126 - Pumps.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Pumps. 157.126 Section 157.126... Washing (COW) System on Tank Vessels Design, Equipment, and Installation § 157.126 Pumps. (a) Crude oil must be supplied to the COW machines by COW system pumps or cargo pumps. (b) The pumps under paragraph...

An improved inventory of polychlorinated biphenyls in China: A case study on PCB-153

Science.gov (United States)

Xu, Yue; Tian, Chongguo; Wang, Xiaoping; Ma, Jianmin; Tang, Jianhui; Chen, Yingjun; Li, Jun; Zhang, Gan

2018-06-01

Emission inventory of pollutants is essential for the environmental fate study and management of the pollutant. To construct a reasonable PCB (polychlorinated biphenyls) inventory in China, this study estimates PCB usage and emission using power generating capacity, installed capacity of power plants and transformer substations, population density and GDP as surrogates. Inventory of representative PCB (PCB-153) with a resolution of 1/4° latitude × 1/4° longitude in China from 1952 to 2005 was generated and assessed as an example. Totally, about 20.3 kt PCBs were applied in China, of which 179 t were PCB-153. By the end of 2005, most of them (56.4%) were emitted into the soil, 2.7% entered the air, and about 20.8% was sealed in storage site or still in service. Historical emissions exhibited increasing trends after 1968, 1984 and 1994, which were mainly associated with usage or disposal processes. Although primary emission has been declined since 2005, the influence of secondary emission from soils, unintentionally produced PCBs (UP-PCB), and reemission from storage sites could be a long-lasting issue in the future. This new emission inventory improves previous PCB emission inventory significantly, which underestimated PCB emission in China considerably.

Dynamics of PCB removal and detoxification in historically contaminated soils amended with activated carbon

Energy Technology Data Exchange (ETDEWEB)

Vasilyeva, Galina K., E-mail: gkvasilyeva@issp.psn.r [Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino 142290 (Russian Federation); Strijakova, Elena R. [Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino 142290 (Russian Federation); Nikolaeva, Svetlana N.; Lebedev, Albert T. [Chemistry Department of Moscow State University, Moscow (Russian Federation); Shea, Patrick J. [School of Natural Resources, University of Nebraska-Lincoln (United States); Department of Environmental, Agricultural and Occupational Health, University of Nebraska Medical Center, Lincoln, NE 68583-0817 (United States)

2010-03-15

Activated carbon (AC) can help overcome toxicity of pollutants to microbes and facilitate soil bioremediation. We used this approach to treat a Histosol and an Alluvial soil historically contaminated with PCB (4190 and 1585 mg kg{sup -1}, respectively; primarily tri-, tetra- and pentachlorinated congeners). Results confirmed PCB persistence; reductions in PCB extractable from control and AC-amended soils were mostly due to a decrease in tri- and to some extent tetrachlorinated congeners as well as formation of a bound fraction. Mechanisms of PCB binding by soil and AC were different. In addition to microbial degradation of less chlorinated congeners, we postulate AC catalyzed dechlorination of higher chlorinated congeners. A large decrease in bioavailable PCB in AC-amended soils was demonstrated by greater clover germination and biomass. Phytotoxicity was low in treated soils but remained high in untreated soils for the duration of a 39-month experiment. These observations indicate the utility of AC for remediation of soils historically contaminated with PCB. - Activated carbon promotes remediation of soils historically contaminated with PCB.

Dynamics of PCB removal and detoxification in historically contaminated soils amended with activated carbon

International Nuclear Information System (INIS)

Vasilyeva, Galina K.; Strijakova, Elena R.; Nikolaeva, Svetlana N.; Lebedev, Albert T.; Shea, Patrick J.

2010-01-01

Activated carbon (AC) can help overcome toxicity of pollutants to microbes and facilitate soil bioremediation. We used this approach to treat a Histosol and an Alluvial soil historically contaminated with PCB (4190 and 1585 mg kg -1 , respectively; primarily tri-, tetra- and pentachlorinated congeners). Results confirmed PCB persistence; reductions in PCB extractable from control and AC-amended soils were mostly due to a decrease in tri- and to some extent tetrachlorinated congeners as well as formation of a bound fraction. Mechanisms of PCB binding by soil and AC were different. In addition to microbial degradation of less chlorinated congeners, we postulate AC catalyzed dechlorination of higher chlorinated congeners. A large decrease in bioavailable PCB in AC-amended soils was demonstrated by greater clover germination and biomass. Phytotoxicity was low in treated soils but remained high in untreated soils for the duration of a 39-month experiment. These observations indicate the utility of AC for remediation of soils historically contaminated with PCB. - Activated carbon promotes remediation of soils historically contaminated with PCB.

Two-step bioleaching of copper and gold from discarded printed circuit boards (PCB).

Science.gov (United States)

Işıldar, Arda; van de Vossenberg, Jack; Rene, Eldon R; van Hullebusch, Eric D; Lens, Piet N L

2016-11-01

An effective strategy for environmentally sound biological recovery of copper and gold from discarded printed circuit boards (PCB) in a two-step bioleaching process was experimented. In the first step, chemolithotrophic acidophilic Acidithiobacillus ferrivorans and Acidithiobacillus thiooxidans were used. In the second step, cyanide-producing heterotrophic Pseudomonas fluorescens and Pseudomonas putida were used. Results showed that at a 1% pulp density (10g/L PCB concentration), 98.4% of the copper was bioleached by a mixture of A. ferrivorans and A. thiooxidans at pH 1.0-1.6 and ambient temperature (23±2°C) in 7days. A pure culture of P. putida (strain WCS361) produced 21.5 (±1.5)mg/L cyanide with 10g/L glycine as the substrate. This gold complexing agent was used in the subsequent bioleaching step using the Cu-leached (by A. ferrivorans and A. thiooxidans) PCB material, 44.0% of the gold was mobilized in alkaline conditions at pH 7.3-8.6, and 30°C in 2days. This study provided a proof-of-concept of a two-step approach in metal bioleaching from PCB, by bacterially produced lixiviants. Copyright © 2015 Elsevier Ltd. All rights reserved.

40 CFR 761.298 - Decisions based on PCB concentration measurements resulting from sampling.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Decisions based on PCB concentration... Cleanup and On-Site Disposal of Bulk PCB Remediation Waste and Porous Surfaces in Accordance With § 761.61(a)(6) § 761.298 Decisions based on PCB concentration measurements resulting from sampling. (a) For...

Determination of the human cytochrome P450 monooxygenase catalyzing the enantioselective oxidation of 2,2',3,5',6-pentachlorobiphenyl (PCB 95) and 2,2',3,4,4',5',6-heptachlorobiphenyl (PCB 183).

Science.gov (United States)

Nagayoshi, Haruna; Kakimoto, Kensaku; Konishi, Yoshimasa; Kajimura, Keiji; Nakano, Takeshi

2017-10-17

2,2',3,5',6-Pentachlorobiphenyl (PCB 95) and 2,2',3,4,4',5',6-heptachlorobiphenyl (PCB 183) possess axial chirality and form the aS and aR enantiomers. The enantiomers of these congeners have been reported to accumulate in the human body enantioselectively via unknown mechanisms. In this study, we determined the cytochrome P450 (CYP) monooxygenase responsible for the enantioselective oxidization of PCB 95 and PCB 183, using a recombinant human CYP monooxygenase. We evaluated 13 CYP monooxygenases, namely CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2, CYP3A4, CYP3A5, CYP4F2, and aromatase (CYP19), and revealed that CYP2A6 preferably oxidizes aS-PCB 95 enantioselectively; however, it did not oxidize PCB 183. The enantiomer composition was elevated from 0.5 (racemate) to 0.54. In addition, following incubation with CYP2A6, the enantiomer fraction (EF) of PCB 95 demonstrated a time-dependent increase.

40 CFR 761.316 - Interpreting PCB concentration measurements resulting from this sampling scheme.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Interpreting PCB concentration... § 761.79(b)(3) § 761.316 Interpreting PCB concentration measurements resulting from this sampling... composite is 20 µg/100 cm2, then the entire 9.5 square meters has a PCB surface concentration of 20 µg/100...

Toxicological profile of ultrapure 2,2',3,4,4',5,5'-heptachlorbiphenyl (PCB 180) in adult rats.

Science.gov (United States)

Viluksela, Matti; Heikkinen, Päivi; van der Ven, Leo T M; Rendel, Filip; Roos, Robert; Esteban, Javier; Korkalainen, Merja; Lensu, Sanna; Miettinen, Hanna M; Savolainen, Kari; Sankari, Satu; Lilienthal, Hellmuth; Adamsson, Annika; Toppari, Jorma; Herlin, Maria; Finnilä, Mikko; Tuukkanen, Juha; Leslie, Heather A; Hamers, Timo; Hamscher, Gerd; Al-Anati, Lauy; Stenius, Ulla; Dervola, Kine-Susann; Bogen, Inger-Lise; Fonnum, Frode; Andersson, Patrik L; Schrenk, Dieter; Halldin, Krister; Håkansson, Helen

2014-01-01

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 weight gain was retarded at 1700 mg/kg during loading dosing, but recovered thereafter. The most sensitive endpoint of toxicity that was used for risk characterization was altered open field behavior in females; i.e. increased activity and distance moved in the inner zone of an open field suggesting altered emotional responses to unfamiliar environment and impaired behavioral inhibition. Other dose-dependent changes included decreased serum thyroid hormones with associated histopathological changes, altered tissue retinoid levels, decreased hematocrit and hemoglobin, decreased follicle stimulating hormone and luteinizing hormone levels in males and increased expression of DNA damage markers in liver of females. Dose-dependent hypertrophy of zona fasciculata cells was observed in adrenals suggesting activation of cortex. There were gender differences in sensitivity and toxicity profiles were partly different in males and females. PCB 180 adipose tissue concentrations were clearly above the general human population levels, but close to the levels in highly exposed populations. The results demonstrate a distinct toxicological profile of PCB 180 with lack of dioxin-like properties required for assignment of WHO toxic equivalency factor. However, PCB 180 shares several toxicological

Relation among cytochrome P450, AH-active PCB congeners and dioxin equivalents in pipping black-crowned night-heron embryos

Science.gov (United States)

Rattner, B.A.; Hatfield, J.S.; Melancon, M.J.; Custer, T.W.; Tillitt, D.E.

1994-01-01

Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from a relatively uncontaminated site (next to Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). Hepatic cytochrome P-450-associated monooxygenases and cytochrome P-450 proteins, induced up to 85-fold relative to the reference site, were associated with concentrations of total polychlorinated biphenyls (PCBs) and 11 PCB congeners that are presumed to express toxicity through the arylhydrocarbon (Ah) receptor. Multiple regression revealed that up to 86% of the variation of cytochrome P450 measurements was accounted for by variation in the concentration of these PCB congeners. Toxic equivalents (TEQs) of sample extracts, predicted mathematically (summed product of PCB congener concentrations and toxic equivalency factors), and dioxin equivalents (TCDD-EQs), derived by bioassay (ethoxyresorufin-O-dealkylase activity of treated H4IIE rat hepatoma cells), were greatest in Cat Island samples. Cytochrome P450-associated monooxygenases and cytochrome P450 proteins were related to TEQs and TCDD-EQs; adjusted r-2 often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data extend previous observations in heron embryos of an association between P450 and total PCB burdens to include Ah-active PCB congeners, and presumably other compounds, which interact similarly with the Ah receptor. Benzyloxyresorufin O-dealkylase, ethoxyresorufin O-dealkylase, and cytochrome P450 1A appear to be the most reliable measures of exposure to Ah-active PCB congeners in black-crowned night-heron embryos. These findings provide further evidence that cytochrome P450-associated parameters have considerable value as a biomarker for assessing environmental contamination of wetlands.

Indirect Evidence Link PCB Dehalogenation with Geobacteraceae in Anaerobic Sediment-Free Microcosms.

Science.gov (United States)

Praveckova, Martina; Brennerova, Maria V; Holliger, Christof; De Alencastro, Felippe; Rossi, Pierre

2016-01-01

Although polychlorinated biphenyls (PCBs) production was brought to a halt 30 years ago, recalcitrance to degradation makes them a major environmental pollutant at a global scale. Previous studies confirmed that organohalide-respiring bacteria (OHRB) were capable of utilizing chlorinated congeners as electron acceptor. OHRB belonging to the Phyla Chloroflexi and Firmicutes are nowadays considered as the main PCB-dechlorinating organisms. In this study, we aimed at exploring the involvement of other taxa in PCB dechlorination using sediment-free microcosms (SFMs) and the Delor PCB mixture. High rates of congener dehalogenation (up to 96%) were attained in long-term incubations of up to 692 days. Bacterial communities were dominated by Chloroflexi, Proteobacteria, and Firmicutes, among strictly simplified community structures composed of 12 major phyla only. In a first batch of SFMs, Dehalococcoides mccartyi closely affiliated with strains CG4 and CBDB1 was considered as the main actor associated with congener dehalogenation. Addition of 2-bromoethanesulfonate (BES), a known inhibitor of methanogenic activity in a second batch of SFMs had an adverse effect on the abundance of Dehalococcoides sp. Only two sequences affiliated to this Genus could be detected in two (out of six) BES-treated SFMs, contributing to a mere 0.04% of the communities. BES-treated SFMs showed very different community structures, especially in the contributions of organisms involved in fermentation and syntrophic activities. Indirect evidence provided by both statistical and phylogenetic analysis validated the implication of a new cluster of actors, distantly affiliated with the Family Geobacteraceae (Phylum δ-Proteobacteria), in the dehalogenation of low chlorinated PCB congeners. Members of this Family are known already for their dehalogenation capacity of chlorinated solvents. As a result, the present study widens the knowledge for the phylogenetic reservoir of indigenous PCB dechlorinating

Turtle sex determination assay: Mass balance and responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin and 3,3',4,4',5-pentachlorobiphenyl

Science.gov (United States)

Gale, Robert W.; Bergeron, Judith M.; Willingham, Emily J.; Crews, David

2002-01-01

Polyhalogenated hydrocarbons have been implicated in the anomalous sexual differentiation of mammals and reptiles. Here, a temperature-sensitive turtle sex determination assay using the red-eared slider (Trachemys scripta elegans) was used to determine the estrogenic or antiestrogenic activity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126). Neither TCDD nor PCB-126 showed a statistically significant difference in the resulting sex ratios (Fisher's exact test, p < 0.45). As a consequence of the dosing technique (eggshell spotting), the shell retained 90 and 96% of the dose for PCB-126 and TCDD, respectively, similar to retention of estradiol-17β. However, the dosing allowed transfer of sufficient chemical to achieve tissue concentrations that were greater than most concentrations reported for environmentally incurred residues. Similar relative mass distributions of PCB-126 and TCDD were observed in albumin (14–20%), yolk (55–70%), and embryo (16–25%). Relative concentration distributions in the embryo approached those in the yolk, 37 to 40% and 40 to 52%, respectively, while relative concentrations in the albumin remained at 11 to 20%. Lipid-normalized TCDD and PCB-126 concentrations were 30- to 40-fold greater in the embryo than in the yolk. It is hypothesized that nonpassive partitioning processes may have occurred in the embryo.

Inhibition of aromatase activity by methyl sulfonyl PCB metabolites in primary culture of human mammary fibroblasts

Energy Technology Data Exchange (ETDEWEB)

Berg, M. van den; Heneweer, M.; Geest, M. de; Sanderson, T. [Inst. for Risk Assessment Sciences and Utrecht Univ. (Netherlands); Jong, P. de [St. Antonius Hospital, Nieuwegein (Netherlands); Bergman, A. [Stockholm Univ., Stockholm (Sweden)

2004-09-15

results that were obtained when using the human adrenocorticocarcinoma cell line H295R. Previous studies proved these cells to be a suitable tool for studying inhibitory effects of xenobiotics on aromatase activity. The aim of this study was to investigate effects on aromatase by MeSO{sub 2}-PCB exposure and elucidate a possible mechanism of action.

Environment Canada defends decision to ban PCB waste exports

International Nuclear Information System (INIS)

Anon.

1995-01-01

The position of Environment Canada in banning the export of PCB waste to the United States was defended as falling within their jurisdiction under provisions of the the Canadian Environmental Protection Act. The United States had previously banned the import of Canadian PCBs, but when it reversed its decision Environment Canada posted an Interim Order, upholding the ban. The decision to do so was based on protection of the large investment that was made to develop the Canadian PCB incineration facility in Swan Lake, Alberta. Canada also had an obligation under the Basel Convention to reduce it cross boundary movement of hazardous waste and provide adequate destruction facilities in Canada. Legal implications of PCB exports and the uncertainty of continuing access to American facilities were also cited as reasons for issuing the Interim Order

Associations between plasma concentrations of PCB 28 and possible indoor exposure sources in Danish school children and mothers

DEFF Research Database (Denmark)

Egsmose, Emilie Lund; Bräuner, Elvira Vaclavik; Frederiksen, Marie

2016-01-01

Background: Polychlorinated biphenyls (PCBs) are ubiquitously present in the environment and are suspected ofcarcinogenic, neurotoxic and immunotoxic effects. Significantly higher plasma concentrations of the congener PCB 28 occur in children compared to adults. Exposure in schools may contribute...... to this difference. Objective: To determine whether increased blood plasma concentrations of PCB 28 in Danish school children andmothers are associated with living in homes or attending schools constructed in the PCB period (1959–1977). Methods: PCB 28 was analyzed in plasma samples from 116 children aged 6–11 years...... and 143 mothers living inan urban and a rural area in Denmark and participating in the European pilot project DEMOCOPHES (Demonstrationof a study to COordinate and Perform Human Biomonitoring on a European Scale). In Denmark, PCBs wereused in construction in the period 1950–1977, and year of construction...

Microbial ecology of bacterially mediated PCB biodegradation

International Nuclear Information System (INIS)

Pettigrew, C.A. Jr.

1989-01-01

The roles of plasmid mediated and consortia mediated polychlorinated biphenyl (PCB) biodegradation by bacterial populations isolated from PCB contaminated freshwater sediments were investigated. PCB degrading bacteria were isolated by DNA:DNA colony hybridization, batch enrichments, and chemostat enrichment. Analysis of substrate removal and metabolite production were done using chlorinated biphenyl spray plates, reverse phase high pressure liquid chromatography, Cl - detection, and 14 C-labeled substrate mineralization methods. A bacterial consortium, designated LPS10, involved in a concerted metabolic attack on chlorinated biphenyls, was shown to mineralize 4-chlorobiphenyl (4CB) and 4,4'-dichlorobiphenyl (4,4' CB). The LPS10 consortium was isolated by both batch and chemostat enrichment using 4CB and biphenyl (BP) as sole carbon source and was found to have tree bacterial isolates that predominated; these included: Pseudomonas, testosteroni LPS10A which mediated the breakdown of 4CB and 4,4' CB to the putative meta-cleavage product and subsequently to 4-chlorobenzoic acid (4CBA), an isolate tentatively identified as an Arthrobacter sp. LPS10B which mediated 4CBA degradation, and Pseudomonas putida by A LPS10C whose role in the consortium has not been determined

Assessment of questionnaire-based PCB exposure focused on food frequency in birth cohorts in Japan.

Science.gov (United States)

Eguchi, Akifumi; Otake, Masae; Hanazato, Masamichi; Suzuki, Norimichi; Matsuno, Yoshiharu; Nakaoka, Hiroko; Todaka, Emiko; Mori, Chisato

2017-02-01

We investigated the relationship between food frequency questionnaire (FFQ) responses and serum polychlorinated biphenyl (PCB) levels of mothers and fathers recruited from the Chiba Regional Center, which is one of the 15 regional centers of the Japan Environment and Children's Study (mothers: n = 1477, fathers: n = 219). The expected PCB values were estimated from the participants' FFQ answers and medical records (age, body mass index and number of deliveries). Based on the stepwise forward selection results of Bayesian regression models, age and fish and egg consumption were positively associated with PCB concentrations and a number of deliveries were negatively associated with PCB concentrations in mothers, whereas only age was positively associated with PCB concentrations in fathers.These findings indicated that the estimation of daily dietary intake may be useful for the prediction of PCB concentration for mothers.

Uptake and depuration of PCB-153 in edible shrimp Palaemonetes varians and human health risk assessment.

Science.gov (United States)

Grilo, T F; Cardoso, P G; Pato, P; Duarte, A C; Pardal, M A

2014-03-01

A medium-term mesocosm exposure study was conducted to elucidate bioaccumulation and depuration of polychlorinated biphenyl congener 153 (PCB-153) in edible shrimp Palaemonetes varians. Over the 15-day exposure period, shrimp under different exposure concentrations exhibited a significant increase in PCB-153 concentration compared with control organisms. Distinct bioaccumulation patterns and uptake rates were observed depending on the exposure concentrations. For low PCB-153 exposure levels (0.25μgL(-1)), accumulation followed a saturation model, reaching an apparent steady state after fifteen days exposure. For intermediate (2.5μgL(-1)) and high PCB-153 levels (25μgL(-1)), accumulation was faster and linear. In addition, the bioaccumulation rate was not proportional to PCB-153 concentration, and the bioaccumulation was higher at intermediate exposure concentrations. Regarding the depuration phase, P. varians lost up to 30% of PCB-153 after 72h and levels continued slowly to decrease until the end of the 30-d experimental period. However, PCB-153 levels in shrimp did not reach background values, and those exposed to moderate and high PCB-153 concentrations presented contamination levels much higher than the regulatory limit for human food consumption (75ngg(-1) ww for Σ6 PCB). Copyright © 2013 Elsevier Inc. All rights reserved.

5 CFR 1201.126 - Final decisions.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Final decisions. 1201.126 Section 1201.126 Administrative Personnel MERIT SYSTEMS PROTECTION BOARD ORGANIZATION AND PROCEDURES PRACTICES AND PROCEDURES Procedures for Original Jurisdiction Cases Special Counsel Disciplinary Actions § 1201.126 Final...

The effect of anthropogenic contaminations (PAH, PCB) on terrestrial annelids in conurban ecosystems. Final report; Einfluss von anthropogenen Schadstoffen (PAK und PCB) auf terrestrische Invertebraten urbaner Oekosysteme. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Achazi, R.K.; Beylich, A.; Chroszcz, G.; Dueker, C.; Heck, M.; Henneken, M.; Flenner, C.; Froehlich, E.; Garbers, U.; Khan, M.A.; Kreibich, M.; Kronshage, J.; Philippe, L.; Pilz, C.; Rothe, B.; Schabedoth, E.; Schaub, K.; Scheiwe, E.; Schmid, C.; Steudel, I.; Struwe, M.; Throl, C.; Wuertz, S. [Freie Univ. Berlin (Germany); Back, H.; Naehring, D.; Thielemann, U. [Gesellschaft fuer Angewandte Oekologie und Umweltplanung mbH, Nussloch (Germany)

1997-09-23

The project was conducted from August 1993 until May 1997. The objectives were (a) an elaboration of effect concentrations and index values for organic contaminants (PAH, PCB) and heavy metals in soil of conurbations for the community of decomposers, (b) the improvement of a biotest system for the evaluation of the habitat function of contaminated soils and (c) to obtain informations concerning a controlled utilization of contaminated areas. For that purpose field investigations in former sewage water irrigation areas of Berlin, Germany, concerning the abundance, species composition and dominance structure of terrestrial annelids (Enchytraeids, Lumbricids) were performed, as well as bioassays using contaminated soils of these sites and soils spiked with bezo(a)pyrene, fluoranthene, PCB 52, Cd and Cu and experiments on accumulation, elimination and biotransformation in annelids. 12 of the 17 sites investigated lacked earthworms, while only 2 sites lacked enchytraeids. The abundance of enchytraeids was in the range of 500 to 12.500/m{sup 2}, compared to 25.000 to 280.000/m{sup 2} on reference sites. The hostility of the soils of former irrigation fields to annelids was confirmed by lamina bait tests and by bioassays with Enchytraeus crypticus, E. albidus, E. buchholzi and Eisenia f. fetida. The ecotoxicity of the combined contaminants was enforced by the acidity and the degradation of the soils. The toxicity of organic and inorganic contaminants to terrestrial annelids was definitely proved by reproduction tests in the agar test system. The applied methods of investigation can be used for evaluation of contaminated soils. (orig.) [Deutsch] Das Projekt wurde von August 1993 bis Mai 1997 durchgefuehrt. Ziele waren die Erarbeitung (a) von Wirkschwellen fuer organische Schadstoffgruppen (PAK, PCB) und Schwermetalle im Boden fuer Destruenten urbaner Oekosysteme, (b) von Biotestsystemen zur Bewertung der Lebensraumfunktion belasteter Boeden und (c) von Hinweisen zur

miR-126 Functions as a Tumor Suppressor in Osteosarcoma by Targeting Sox2

Directory of Open Access Journals (Sweden)

Chenglin Yang

2013-12-01

Full Text Available Osteosarcoma (OS is the most common malignant bone tumor in children and young adults, the early symptoms and signs of which are non-specific. The discovery of microRNAs (miRNAs provides a new avenue for the early diagnosis and treatment of OS. miR-126 has been reported to be highly expressed in vascularized tissues, and is recently widely studied in cancers. Herein, we explored the expression and significance of miR-126 in OS. Using TaqMan RT-PCR analysis, we analyzed the expression of miR-126 in 32 paired OS tumor tissues and 4 OS cell lines and found that miR-126 was consistently under-expressed in OS tissues and cell lines compared with normal bone tissues and normal osteoblast cells (NHOst, respectively. As miR-126 is significantly decreased in OS tissues and cell lines, we sought to compensate for its loss through exogenous transfection into MG-63 cells with a miR-126 mimic. Ectopic expression of miR-126 inhibited cell proliferation, migration and invasion, and induced apoptosis of MG-63 cells. Moreover, bioinformatic prediction suggested that the sex-determining region Y-box 2 (Sox2 is a target gene of miR-126. Using mRNA and protein expression analysis, luciferase assays and rescue assays, we demonstrate that restored expression of Sox2 dampened miR-126-mediated suppression of tumor progression, which suggests the important role of miR-126/Sox2 interaction in tumor progression. Taken together, our data indicate that miR-126 functions as a tumor suppressor in OS, which exerts its activity by suppressing the expression of Sox2.

32 CFR 643.126 - Transportation licenses.

Science.gov (United States)

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Transportation licenses. 643.126 Section 643.126... ESTATE Additional Authority of Commanders § 643.126 Transportation licenses. Installation commanders are... free competitive proposals of all available companies or individuals. (b) DD Form 694 (Transportation...

Behavioral changes following PCB 153 exposure in the Spontaneously Hypertensive rat – an animal model of Attention-Deficit/Hyperactivity disorder

Science.gov (United States)

2014-01-01

Background Attention-Deficit/Hyperactivity Disorder (ADHD) is a behavioral disorder affecting 3-5% of children. Although ADHD is highly heritable, environmental factors like exposure during early development to various toxic substances like polychlorinated biphenyls (PCBs) may contribute to the prevalence. PCBs are a group of chemical industrial compounds with adverse effects on neurobiological and cognitive functioning, and may produce behavioral impairments that share significant similarities with ADHD. The present study examined the relation between exposure to PCB 153 and changes in ADHD-like behavior in an animal model of ADHD, the spontaneously hypertensive rats (SHR/NCrl), and in Wistar Kyoto (WKY/NHsd) controls. Methods SHR/NCrl and WKY/NHsd, males and females, were orally given PCB 153 dissolved in corn oil at around postnatal day (PND) 8, 14, and 20 at a dosage of 1, 3 or 6 mg/kg bodyweight at each exposure. The control groups were orally administered corn oil only. The animals were behaviorally tested for exposure effects from PND 37 to 64 using an operant procedure. Results Exposure to PCB 153 was associated with pronounced and long-lasting behavioral changes in SHR/NCrl. Exposure effects in the SHR/NCrl depended on dose, where 1 mg/kg tended to reduce ADHD-like behaviors and produce opposite behavioral effects compared to 3 mg/kg and 6 mg/kg, especially in the females. In the WKY/NHsd controls and for the three doses tested, PCB 153 exposure produced a few specific behavioral changes only in males. The data suggest that PCB 153 exposure interacts with strain and sex, and also indicate a non-linear dose–response relation for the behaviors observed. Conclusions Exposure to PCB 153 seems to interact with several variables including strain, sex, dose, and time of testing. To the extent that the present findings can be generalized to humans, exposure effects of PCB 153 on ADHD behavior depends on amount of exposure, where high doses may aggravate ADHD

Optimal production planning for PCB assembly

CERN Document Server

Ho, William

2006-01-01

Focuses on the optimization of the Printed circuit board (PCB) assembly lines' efficiency. This book integrates the component sequencing and the feeder arrangement problems together for the pick-and-place machine and the chip shooter machines.

18 CFR 284.126 - Reporting requirements.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Reporting requirements. 284.126 Section 284.126 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION... AUTHORITIES Certain Transportation by Intrastate Pipelines § 284.126 Reporting requirements. (a) Notice of...

PCDD, PCDF, and PCB contamination of air and inhalable particulate in Rome

International Nuclear Information System (INIS)

Turrio-Baldassarri, L.; Carere, A.; Di Domenico, A.; Fuselli, S.; Iacovella, N.; Rodriguez, F.

1994-01-01

The isomer specific determination of PCDD, PCDF and PCB was carried out on samples of air and inhalable particulate from Rome. Samples were taken daily for six months and pooled to yield two samples per month. Normal PCDD + PCDF concentrations expressed in TEQ ranged from 48 to 87 fg/m 3 , while total PCB ranged from 0.1 to 1.4 ng/m 3 . The 2, 3, 7, 8-substituted PCDD and PCDF congener pattern is shown together with the PCB congener pattern. (orig.)

2,2',3,3',6,6'-Hexachlorobiphenyl (PCB 136) is Enantioselectively Oxidized to Hydroxylated Metabolites by Rat Liver Microsomes

Science.gov (United States)

Wu, Xianai; Pramanik, Ananya; Duffel, Michael W.; Hrycay, Eugene G.; Bandiera, Stelvio M.; Lehmler, Hans-Joachim; Kania-Korwel, Izabela

2011-01-01

Developmental exposure to multiple-ortho substituted polychlorinated biphenyls (PCBs) causes adverse neurodevelopmental outcomes in laboratory animals and humans by mechanisms involving the sensitization of Ryanodine receptors (RyRs). In the case of PCB 136, the sensitization of RyR is enantiospecific, with only (-)-PCB 136 being active. However, the role of enantioselective metabolism in the developmental neurotoxicity of PCB 136 is poorly understood. The present study employed hepatic microsomes from phenobarbital (PB-), dexamethasone (DEX-) and corn oil (VEH-)treated male Sprague-Dawley rats to investigate the hypothesis that PCB 136 atropisomers are enantioselectively metabolized by P450 enzymes to potentially neurotoxic, hydroxylated PCB 136 metabolites. The results demonstrated the time- and isoform-dependent formation of three metabolites, with 5-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol) being the major metabolite. The formation of 5-OH-PCB 136 increased with the activity of P450 2B enzymes in the microsomal preparation, which is consistent with PCB 136 metabolism by rat P450 2B1. The minor metabolite 4-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-4-ol) was produced by a currently unidentified P450 enzymes. An enantiomeric enrichment of (-)-PCB 136 was observed in microsomal incubations due to the preferential metabolism of (+)-PCB 136 to the corresponding 5-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol) atropisomer. 4-OH-PCB 136 displayed an enrichment of the atropisomer formed from (-)-PCB 136; however, the enrichment of this metabolite atropisomer didn't affect the enantiomeric enrichment of the parent PCB because 4-OH-PCB 136 is only a minor metabolite. Although the formation of 5- and 4-OH-PCB 136 atropisomers increased with time, the enantioselective formation of the OH-PCB metabolites resulted in constant enantiomeric enrichment, especially at later incubation times. These observations not only demonstrate that the chiral signatures of

Nonlinear dynamic response of a 'flexible-and-heavy' printed circuit board (PCB) to an impact load applied to its support contour

International Nuclear Information System (INIS)

Suhir, E; Vujosevic, M; Reinikainen, T

2009-01-01

Based on the developed simple and physically meaningful analytical ('mathematical') stress model, we evaluate some major parameters (amplitude, frequency, maximum acceleration, stresses and strains) of the response of a 'flexible-and-heavy' square simply supported printed circuit board (PCB) to an impact drop load applied to its support contour. The analysis is restricted to the first mode of vibrations and is carried out in application to the PCB design employed in an advanced accelerated test setup (test vehicle). This setup is aimed at the assessment of the performance, in accelerated test conditions on the board level, of packaging materials (and, first of all, BGA solder joint interconnections) subjected to dynamic (drop or shock) loading. It is anticipated that heavy masses could be mounted on the PCB to accelerate its dynamic response to an impact load. These masses are expected to be small in size, so that while changing the total mass of the board and generating significant inertia forces, they do not affect the board's flexural rigidity or its stiffness with respect to the in-plane loading. The PCB's contour is considered non-deformable, which is indeed the case in many practical situations. This circumstance, if the drop height and/or the induced inertia forces are significant, leads to elevated in-plane ('membrane') stresses in the PCB and, as a result of that, to the nonlinear response of the board to the impact load: the relationship between the magnitude of the load (determined by the initial impact velocity) and the induced PCB deflections becomes geometrically nonlinear, with a rigid cubic characteristic of the restoring force. The carried out numerical example, although reflects the characteristics of the PCB and loading conditions in an actual experimental setup, is merely an illustration of the general concept and is intended to demonstrate the abilities of the suggested method. Predictions based on this method agree well with the finite element

Fasting augments PCB impact on liver metabolism in anadromous Arctic Char

Science.gov (United States)

Vijayan, M.M.; Aluru, N.; Maule, A.G.; Jorgensen, E.H.

2006-01-01

Anadromous arctic char (Salvelinus alpinus) undertake short feeding migrations to seawater every summer and accumulate lipids, while the rest of the year is spent in fresh water where the accumulated lipid reserves are mobilized. We tested the hypothesis that winter fasting and the associated polychlorinated biphenyls' (PCBs) redistribution from lipid depots to critical tissues impair the liver metabolic capacity in these animals. Char were administered Aroclor 1254 (0, 1, 10, and 100 mg/ kg body mass) orally and maintained for 4 months without feeding to mimic seasonal winter fasting, while fed groups (0 and 100 mg Aroclor 1254/kg) were maintained for comparison. A clear dose-related increase in PCB accumulation and cytochrome P4501A (CYP1A) protein content was observed in the livers of fasted fish. This PCB concentration and CYP1A response with the high dose of Aroclor were 1.5-fold and 3-fold greater in the fasted than in the fed fish, respectively. In fed fish, PCB exposure lowered liver glycogen content, whereas none of the other metabolic indicators were significantly affected. In fasted fish, PCB exposure depressed liver glycogen content and activities of glucose-6-phosphate dehydrogenase, alanine aminotransferase, lactate dehydrogenase, and phosphoenolpyruvate carboxykinase and elevated 3-hydroxyacylcoA dehydrogenase activity and glucocorticoid receptor protein expression. There were no significant impacts of PCB on heat shock protein 70 (hsp70) and hsp90 contents in either fed or fasted fish. Collectively, our study demonstrates that winter emaciation associated with the anadromous lifestyle predisposes arctic char to PCB impact on hepatic metabolism including disruption of the adaptive metabolic responses to extended fasting. ?? 2006 Oxford University Press.

Dicty_cDB: AHB126 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available AH (Link to library) AHB126 (Link to dictyBase) - - - Contig-U16336-1 AHB126P (Link... to Original site) AHB126F 598 AHB126Z 500 AHB126P 1078 - - Show AHB126 Library AH (Link to library) Clone ID AHB126 (Link to dict...yBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig Contig-U16336-1 Original site URL http://dict...RGIRNHKKNETKFINQCINEIKEELKGDMQKKTVAVQKLTYIQMLGFDI SWASFKIVEVMSCNKFSSKRIGYLAASQSFNEGTDVIVLATHQIRKDFLSSNQSEAYLAL NCLSNICT...KKNETKFINQCINEIKEELKGDMQKKTVAVQKLTYIQMLGFDI SWASFKIVEVMSCNKFSSKRIGYLAASQSFNEGTDVIVLATHQIRKDFLSSNQSEAYLAL NCLSNICT

Effects of DDE and PCB (Aroclor 1260) on experimentally poisoned little brown bats (Myotis lucifugus): Lethal brain concentrations

Science.gov (United States)

Clark, D.R.; Stafford, C.J.

1981-01-01

Adult female little brown bats (Myotis lucifugus) were collected in a church attic in North East, Cecil County, Md. Mealworms (Tenebrio molitor) containing organochlorine pollutants were fed to the bats as follows: 5 bats were dosed at 480 ppm DDE, 12 at 150 ppm DDE, 5 at 1000 ppm polychlorinated biphenyl (PCB; Aroclor 1260), and 12 at 15 ppm PCB. Seven other bats were fed untreated mealworms. The objective was to elevate brain levels of DDE and PCB to lethality and measure these concentrations. During 40 d of dosage, one DDE-dosed bat and two PCB-dosed bats died after exhibiting the prolonged tremor that characterizes organochlorine poisoning. After dosage, surviving bats were starved to elevate brain levels of toxicants, and three additional DDE-dosed bats had tremors before dying. The mean brain concentration of DDE diagnostic of death was estimated as 603 ppm, range 540-670 ppm. This mean is 16-18% higher than means for Mexican free-tailed bats (Tadarida brasiliensis) and common grackles (Quiscalus quiscula), and may indicate less sensitivity. Lethal brain concentrations of Aroclor 1260 were 1300 and 1500 ppm. Such values appear to be higher than values (Aroclor 1254) for brown-headed cowbirds (Molothrus ater). During starvation, DDE-dosed bats lost weight about 24% faster than controls. If smaller amounts of stored DDE cause increases in metabolic rates of nonfeeding bats, as during hibernation or migration, the result could be premature energy depletion and increased mortality.

Simultaneous electrodialytic removal of PAH, PCB, TBT and heavy metals from sediments.

Science.gov (United States)

Pedersen, Kristine B; Lejon, Tore; Jensen, Pernille E; Ottosen, Lisbeth M

2017-08-01

Contaminated sediments are remediated in order to protect human health and the environment, with the additional benefit of using the treated sediments for other activities. Common for many polluted sediments is the contamination with several different pollutants, making remediation challenging with the need of different remedial actions for each pollutant. In this study, electrodialytic remediation (EDR) of sediments was found effective for simultaneous removal of heavy metals and organic pollutants for sediments from Arctic regions - Sisimiut in Greenland and Hammerfest in Norway. The influence of sediment properties and experimental settings on the remediation process was studied by employing multivariate analysis. The importance of the variables studied varied with the pollutant and based on these results it was possible to assess removal processes for the different pollutants. Desorption was found to be important for the removal of heavy metals and TBT, while photolysis was significant for removal of PAH, PCB and TBT. In addition, dechlorination was found to be important for the removal of PCB. The highest removal efficiencies were found for heavy metals, TBT and PCB (>40%) and lower removal efficiencies for PAH (<35%). Copyright © 2017 Elsevier Ltd. All rights reserved.

22 CFR 126.13 - Required information.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Required information. 126.13 Section 126.13... PROVISIONS § 126.13 Required information. (a) All applications for licenses (DSP-5, DSP-61, DSP-73, and DSP... are multiple consignors, consignees or freight forwarders, and all the required information cannot be...

77 FR 11533 - Anniston PCB Superfund Site, Anniston, Calhoun County, Alabama; Notice of Amended Settlement

Science.gov (United States)

2012-02-27

... ENVIRONMENTAL PROTECTION AGENCY [CERCLA-04-2012-3763; FRL 9637-7] Anniston PCB Superfund Site... past response costs concerning the Anniston PCB Superfund Site located in Anniston, Calhoun County.... Submit your comments by Site name Anniston PCB by one of the following methods: www.epa.gov/region4...

Life Cycle Analysis for Treatment and Disposal of PCB Waste at Ashtabula and Fernald

International Nuclear Information System (INIS)

Morris, M.I.

2001-01-01

This report presents the use of the life cycle analysis (LCA) system developed at Oak Ridge National Laboratory (ORNL) to assist two U.S. Department of Energy (DOE) sites in Ohio--the Ashtabula Environmental Management Project near Cleveland and the Fernald Environmental Management Project near Cincinnati--in assessing treatment and disposal options for polychlorinated biphenyl (PCB)-contaminated low-level radioactive waste (LLW) and mixed waste. We will examine, first, how the LCA process works, then look briefly at the LCA system's ''toolbox,'' and finally, see how the process was applied in analyzing the options available in Ohio. As DOE nuclear weapons facilities carry out planned decontamination and decommissioning (D and D) activities for site closure and progressively package waste streams, remove buildings, and clean up other structures that have served as temporary waste storage locations, it becomes paramount for each waste stream to have a prescribed and proven outlet for disposition. Some of the most problematic waste streams throughout the DOE complex are PCB low-level radioactive wastes (liquid and solid) and PCB low-level Resource Conservation and Recovery Act (RCRA) liquid and solid wastes. Several DOE Ohio Field Office (OH) sites have PCB disposition needs that could have an impact on the critical path of the decommissioning work of these closure sites. The Ashtabula Environmental Management Project (AEMP), an OH closure site, has an urgent problem with disposition of soils contaminated by PCB and low-level waste at the edge of the site. The Fernald Environmental Management Project (FEMP), another OH closure site, has difficulties in timely disposition of its PCB-low-level sludges and its PCB low-level RCRA sludges in order to avoid impacting the critical path of its D and D activities. Evaluation of options for these waste streams is the subject of this report. In the past a few alternatives for disposition of PCB low-level waste and PCB low

Life Cycle Analysis for Treatment and Disposal of PCB Waste at Ashtabula and Fernald

Energy Technology Data Exchange (ETDEWEB)

Morris, M.I.

2001-01-11

This report presents the use of the life cycle analysis (LCA) system developed at Oak Ridge National Laboratory (ORNL) to assist two U.S. Department of Energy (DOE) sites in Ohio--the Ashtabula Environmental Management Project near Cleveland and the Fernald Environmental Management Project near Cincinnati--in assessing treatment and disposal options for polychlorinated biphenyl (PCB)-contaminated low-level radioactive waste (LLW) and mixed waste. We will examine, first, how the LCA process works, then look briefly at the LCA system's ''toolbox,'' and finally, see how the process was applied in analyzing the options available in Ohio. As DOE nuclear weapons facilities carry out planned decontamination and decommissioning (D&D) activities for site closure and progressively package waste streams, remove buildings, and clean up other structures that have served as temporary waste storage locations, it becomes paramount for each waste stream to have a prescribed and proven outlet for disposition. Some of the most problematic waste streams throughout the DOE complex are PCB low-level radioactive wastes (liquid and solid) and PCB low-level Resource Conservation and Recovery Act (RCRA) liquid and solid wastes. Several DOE Ohio Field Office (OH) sites have PCB disposition needs that could have an impact on the critical path of the decommissioning work of these closure sites. The Ashtabula Environmental Management Project (AEMP), an OH closure site, has an urgent problem with disposition of soils contaminated by PCB and low-level waste at the edge of the site. The Fernald Environmental Management Project (FEMP), another OH closure site, has difficulties in timely disposition of its PCB-low-level sludges and its PCB low-level RCRA sludges in order to avoid impacting the critical path of its D&D activities. Evaluation of options for these waste streams is the subject of this report. In the past a few alternatives for disposition of PCB low-level waste

Kwantificatie van PCB-componenten in krachtvoeders

NARCIS (Netherlands)

Mazijk, van R.J.; Munsteren, van A.J.; Tuinstra, L.G.M.Th.

1981-01-01

Met behulp van individuele chloorbifenylstandaarden is het PCB-gehalte van een aantal krachtvoeders bepaald, waarbij voor de onbekende componenten een geschatte waarde is gebruikt. Uit deze gehalten is met behulp van omrekeningsfactoren de theoretische DCB-opbrengst bij perchloreren berekend. Dit

PCB transformer fires: the risk in nuclear power plants

International Nuclear Information System (INIS)

Blackmon, K.

1988-01-01

It is estimated that 1/2 of the present nuclear power plants operate with PCB-filled transformer equipment. In an attempt to obtain better estimates of clean-up costs in a nuclear power plant under reasonable-loss scenarios, a study was commissioned. This study was a joint venture between Blackmon-Mooring Steamatic Technologies, Inc., (BMS-TECH) and M and M Protection Consultants. This joint study was conducted at a typical pressurized-water reactor plant consisting of two 1000-MW units. Three specific scenarios were selected and analyzed for this typical power plant. These scenarios were: (1) an electrical failure of a transformer in an isolated switch gear room; (2) a transformer exposed to a 55-gallon transient combustion oil fire in the auxiliary building; and (3) a PCB transformer involved in a major turbine lube fire in the turbine building. Based on results of this study, the insurance carriers for this industry implemented an adjustment in their rate structures for nuclear power plants that have PCB equipment

Effect of biostimulation on the microbial community in PCB-contaminated sediments through periodic amendment of sediment with iron.

Science.gov (United States)

Srinivasa Varadhan, A; Khodadoust, Amid P; Brenner, Richard C

2011-10-01

Reductive dehalogenation of polychlorinated biphenyls (PCBs) by indigenous dehalorespiring microorganisms in contaminated sediments may be enhanced via biostimulation by supplying hydrogen generated through the anaerobic corrosion of elemental iron added to the sediment. In this study, the effect of periodic amendment of sediment with various dosages of iron on the microbial community present in sediment was investigated using phospholipid fatty acid analysis (PLFA) over a period of 18 months. Three PCB-contaminated sediments (two freshwater lake sediments and one marine sediment) were used. Signature biomarker analysis of the microbial community present in all three sediments revealed the enrichment of Dehalococcoides species, the population of which was sustained for a longer period of time when the sediment microcosms were amended with the lower dosage of iron (0.01 g iron per g dry sediment) every 6 months as compared to the blank system (without iron). Lower microbial stress levels were reported for the system periodically amended with 0.01 g of iron per g dry sediment every 6 months, thus reducing the competition from other hydrogen-utilizing microorganisms like methanogens, iron reducers, and sulfate reducers. The concentration of hydrogen in the system was found to be an important factor influencing the shift in microbial communities in all sediments with time. Periodic amendment of sediment with larger dosages of iron every 3 months resulted in the early prevalence of Geobacteraceae and sulfate-reducing bacteria followed by methanogens. An average pH of 8.4 (range of 8.2-8.6) and an average hydrogen concentration of 0.75% (range of 0.3-1.2%) observed between 6 and 15 months of the study were found to be conducive to sustaining the population of Dehalococcoides species in the three sediments amended with 0.01 g iron per g dry sediment. Biostimulation of indigenous PCB dechlorinators by the periodic amendment of contaminated sediments with low dosages of

Polychlorinated biphenyls and organochlorine pesticides in various bird species from northern China

International Nuclear Information System (INIS)

Chen Da; Zhang Xiulan; Mai Bixian; Sun Quanhui; Song Jie; Luo Xiaojun; Zeng, Eddy Y.; Hale, Robert C.

2009-01-01

Little data are available on organochlorine contamination in Chinese terrestrial birds of prey. This study examined the presence of PCBs, DDTs and other organochlorine pesticides in various raptors from northern China. DDE exhibited the highest concentrations among targeted compounds. Greatest levels (23.5-1020 mg/kg lipid weight) were observed in Eurasian sparrowhawks. This may be due to their stopover in southeastern China, where high DDT and dicofol applications have been documented. Residential kestrels exhibited much lower DDE, but similar PCB and HCH concentrations. ΣTEQs and PCB-126/-77 concentration ratios exhibited significant positive correlations with ΣPCB concentrations, respectively. Similar results were also demonstrated by a meta-analysis of previously published data across avian species. Possible hepatic sequestration of coplanar PCB-77, -126, -169 and -118 was observed as liver TEQs increased in Eurasian sparrowhawks. These observations may indicate an induction of CYP1A enzymes, as a result of elevated contamination in some species. - Substantial bioaccumulation of organochlorine contaminants may cause toxic effects (i.e., an induction of Cytochrome P450 enzymes) in birds of prey from the northern China.

Contrasting PCB bioaccumulation patterns among Lake Huron lake trout reflect basin-specific ecology.

Science.gov (United States)

Paterson, Gordon; Ryder, Mark; Drouillard, Ken G; Haffner, G Douglas

2016-01-01

This study collected multiple age classes of lake trout from Lake Huron's Main Basin, Georgian Bay, and North Channel regions to compare and contrast top predator polychlorinated biphenyl (PCB) bioaccumulation patterns in separate compartments of the same ecosystem. Sum PCB concentrations were highest for Main Basin (260 ± 24.9 ng g(-1) wet wt) fish, followed by Georgian Bay (74.6 ± 16.2 ng g(-1) ) and North Channel (42.0 ± 3.3 ng g(-1)) fish. Discriminant functions analysis of lake trout PCB profiles and stable carbon (δ(13)C) and nitrogen (δ(15)N) isotope values clearly distinguished fish by location, indicating high degrees of basin fidelity throughout their lifetimes in addition to highly contrasting PCB bioaccumulation profiles. These unique profiles were not attributable to significant differences in lake trout lipid contents (p = 0.856) or trophic position (δ(15)N; p = 0.334), with rainbow smelt representing the primary prey across the basins. Furthermore, significant differences were observed among the basins for the relationships between PCB biomagnification factors and hydrophobicity. An empirical model for predicting PCB biomagnification in Lake Huron lake trout indicated that basin-specific population growth rates and prey abundances were significant for explaining these contrasting patterns of PCB bioaccumulation. The results of the present study are fundamental for understanding the role of ecology in legacy persistent organic pollutant (POP) bioaccumulation. Specifically, ecosystem characteristics such as prey abundances, foraging ecology, and ultimately consumer growth can regulate the variability of legacy POP bioaccumulation as observed within and among a wide range of freshwater ecosystems. © 2015 SETAC.

PCB congener concentrations in a municipal sewer system in New Jersey, USA

Energy Technology Data Exchange (ETDEWEB)

Loganathan, B. [Murray State Univ., Murray, KY (United States); Botts, J.A. [Aquatic Sciences Consulting, Woodbine, MD (United States); Spadone, J.; McKenna, B. [Linden Roselle Sewerage Authority, Linden, NJ (United States); Sajwan, K.S. [Savannah State Univ., Savannah, GA (United States)

2005-07-01

This paper provided details of a water sampling pilot study conducted in the Linden Roselle Sewerage Authority (LRSA) region in New Jersey. The pilot study was conducted as part of a polychlorinated biphenyl (PCB) monitoring program. Total PCB concentrations in whole water samples in both dissolved and particulate phases were collected at selected locations in the LRSA. PCB loading estimates for dry weather were also provided. Automatic composite sampler equipped with peristaltic pump mechanisms were used to collect the samples in a series of 4 rounds. Sample extracts were then purified and analyzed using a gas chromatograph electron capture detector (GC-ECD). Results showed that in dry weather, total PCBs were between 2.6 to 6.0-fold higher in the western sampling area than in the Roselle Flue, which received sewage flows from residential and commercial sources in the northwest area of the LRSA. Wet weather samples showed only slightly higher total PCBs. Data indicated a source of PCBs in the western portion of the sewershed. In dry weather, higher PCB levels were found in the whole primary influent samples. It was concluded that increased PCB levels were attributed to grit and sludge processing waste streams within a waste water treatment plant. 8 refs., 2 tabs.

Transmutation of 126Sn in spallation targets of accelerator-driven systems

International Nuclear Information System (INIS)

Han, Chi Young; Saito, Masaki; Sagara, Hiroshi

2009-01-01

The practical feasibility of 126 Sn transmutation in spallation targets of accelerator-driven systems was evaluated from the viewpoints of accumulation of radioactive spallation products and neutron production as well as transmutation amount of 126 Sn. A cylindrical liquid 126 Sn target whose length depends on proton beam energy was described, based on a Pb-Bi target design of accelerator-driven system being developed in JAEA. A proton beam of 1.5 GeV-20 mA was estimated to give the transmutation rate of 126 Sn 6.4 kg/yr, which corresponds to the amount of 126 Sn annually discharged in 27 LWRs of 1 GWt and 33 GWd/THM. The equilibrium radioactivity of spallation products would reach 9% of that of 126 Sn transmuted in the spallation target, and the equilibrium toxicity would be just 3%. Some parametric analyses showed that the effective half-life of 126 Sn could be reduced through a proper reduction of the target size. The 126 Sn target was calculated to produce 40 neutrons per proton of 1.5 GeV and give a neutron spectrum very similar to that of the reference Pb-Bi target. As a result, the transmutation of 126 Sn in the spallation target has a high feasibility in terms of better transmutation performance and comparable target performance. (author)

Interaction of the 106-126 prion peptide with lipid membranes and potential implication for neurotoxicity

International Nuclear Information System (INIS)

Dupiereux, Ingrid; Zorzi, Willy; Lins, Laurence; Brasseur, Robert; Colson, Pierre; Heinen, Ernst; Elmoualij, Benaissa

2005-01-01

Prion diseases are fatal neurodegenerative disorders characterized by the accumulation in the brain of an abnormally misfolded, protease-resistant, and β-sheet rich pathogenic isoform (PrP sc ) of the cellular prion protein (PrP c ). In the present work, we were interested to study the mode of prion protein interaction with the membrane using the 106-126 peptide and small unilamellar lipid vesicles as model. As previously demonstrated, we showed by MTS assay that PrP 106-126 induces alterations in the human neuroblastoma SH-SY5Y cell line. We demonstrated for the first time by lipid-mixing assay and by the liposome vesicle leakage test that PrP 106-126, a non-tilted peptide, induces liposome fusion thus a potential cell membrane destabilization, as supported by membrane integrity assay (LDH). By circular dichroism (CD) analysis we showed that the fusogenic property of PrP 106-126 in the presence of liposome is associated with a predominantly β-sheet structure. These data suggest that the fusogenic property associated with a predominant β-sheet structure exhibited by the prion peptides contributes to the neurotoxicity of these peptides by destabilizing cellular membranes. The latter might be attached at the membrane surface in a parallel orientation as shown by molecular modeling

Polychlorinated biphenyl (PCB) contamination in Galveston Bay, Texas: Comparing concentrations and profiles in sediments, passive samplers, and fish.

Science.gov (United States)

Oziolor, Elias M; Apell, Jennifer N; Winfield, Zach C; Back, Jeffrey A; Usenko, Sascha; Matson, Cole W

2018-05-01

The industrialized portion of the Houston Ship Channel (HSC) is heavily contaminated with anthropogenic contaminants, most prominent of which are the polychlorinated biphenyls (PCBs). This contamination has driven adaptive evolution in a keystone species for Galveston Bay, the Gulf killifish (Fundulus grandis). We investigated the geographical extent of PCB impacts by sampling 12 sites, ranging from the heavily industrialized upper portion of the HSC to Galveston Island. At each site, PCB concentrations and profiles were determined in three environmental compartments: sediment, water (polyethylene passive samplers), and fish tissue (resident Gulf killifish). We observed a steep gradient of PCB contamination, ranging from 4.00 to 100,000 ng/g organic carbon in sediment, 290-110,000 ng/g lipid in fish, and 4.5-2300 ng/g polyethylene in passive samplers. The PCB congener profiles in Gulf killifish at the most heavily contaminated sites were shifted toward the higher chlorinated PCBs and were highly similar to the sediment contamination profiles. In addition, while magnitude of total PCB concentrations in sediment and total fish contamination levels were highly correlated between sites, the relative PCB congener profiles in fish and passive samplers were more alike. This strong correlation, along with a lack of dependency of biota-sediment accumulation factors with total contamination rates, confirm the likely non-migratory nature of Gulf killifish and suggest their contamination levels are a good site-specific indicator of contamination in the Galveston Bay area. The spatial gradient of PCB contamination in Galveston Bay was evident in all three matrices studied and was observed effectively using Gulf killifish contamination as an environmentally relevant bioindicator of localized contamination in this environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Current data on the background burden to the persistent organochlorine pollutants HCB, p,p'-DDE as well as PCB 138, PCB 153 and PCB 180 in plasma of the general population in Germany.

Science.gov (United States)

Schettgen, Thomas; Alt, Anne; Esser, Andre; Kraus, Thomas

2015-06-01

Despite their long-term ban, persistent organochlorine compounds like hexachlorobenzene (HCB), p,p'-dichlorodiphenylethylene (DDE) as well as polychlorinated biphenyls (PCBs) are still of environmental concern. For the evaluation of potential occupational or environmental exposures to these substances, it is essential to know the current background burden of the general population. As representative and up-to-date information is missing for Germany, we have analysed a large dataset generated in studies on potential exposure to lower chlorinated PCBs to fill this gap for the levels of HCB, DDE as well as PCB 138, PCB 153 and PCB 180. We have investigated n=2750 plasma samples of persons of the general population living in North Rhine-Westfalia and Hesse aged 6-65 years and sampled between September 2010 and March 2014. For evaluation of the age-dependent accumulation in the general population we have generated seven age groups in the collective. Our laboratory used a validated and quality controlled procedure using GC/MS for quantification of the organochlorine compounds in plasma (LOQ: 0.01μg/L). The median (95th percentile) levels for ∑ PCB 138+PCB 153+PCB 180 were 0.14 (0.73); 0.30 (0.82); 0.38 (0.88); 0.50 (1.14); 0.92; 1.58 (3.54) and 2.41 (4.82)μg/L plasma in the age groups 6-10 years (n=102), 11-17 years (n=499), 18-25 years (n=157), 26-35 years (n=710), 36-45 years (n=400), 46-55 years (n=525) and 56-65 years (n=357), respectively. Similarly, the median (95th percentile) levels of p,p'-DDE were 0.18 (1.24); 0.18 (0.74); 0.24 (0.85); 0.30 (1.20); 0.45 (1.74); 0.64 (3.25) and 0.94 (4.7)μg/L plasma. Finally, the median (95th percentile) of HCB in plasma in these age groups was 0.05 (0.10); 0.06 (0.11); 0.08 (0.15); 0.08 (0.15); 0.11 (0.22); 0.14 (0.42) and 0.20 (0.68)μg/L plasma. Our results prove an overall substantial reduction in the body burden to organochlorine compounds in Germany compared to earlier studies. However, 15% and 3.6% of the examined

PCB Embedded Inductor for High-Frequency ZVS SEPIC Converter

DEFF Research Database (Denmark)

Dou, Yi; Ouyang, Ziwei; Thummala, Prasanth

2018-01-01

The volume and temperature rise of passive components, especially inductors, limit the momentum toward high power density in high-frequency power converters. To address the limitations, PCB integration of passive components should be considered with the benefit of low profile, excellent thermal...... characteristic and cost reduction. This paper investigates an embedded structure of inductors to further increase the power density of a low power DC-DC converter. A pair of coupling inductors have been embedded into the PCB. The detailed embedded process has been described and the characteristics of embedded...

22 CFR 126.3 - Exceptions.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Exceptions. 126.3 Section 126.3 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS... of the United States Government, the Director, Office of Defense Trade Controls may make an exception...

PCB126 modulates fecal microbial fermentation of the dietary fiber inulin

Science.gov (United States)

Exposure to environmental pollutants can alter gut microbial populations. Short-chain fatty acids (SCFAs), produced from gut microbial fermentation of dietary fibers such as inulin, exert numerous effects on host energy metabolism. SCFAs are also linked to health promoting effects, including a red...

Quantitative proteomics analysis reveals perturbation of lipid metabolic pathways in the liver of Atlantic cod (Gadus morhua) treated with PCB 153.

Science.gov (United States)

Yadetie, Fekadu; Oveland, Eystein; Døskeland, Anne; Berven, Frode; Goksøyr, Anders; Karlsen, Odd André

2017-04-01

PCB 153 is one of the most abundant PCB congeners detected in biological samples. It is a persistent compound that is still present in the environment despite the ban on production and use of PCBs in the late 1970s. It has strong tendencies to bioaccumulate and biomagnify in biota, and studies have suggested that it is an endocrine and metabolic disruptor. In order to study mechanisms of toxicity, we exposed Atlantic cod (Gadus morhua) to various doses of PCB 153 (0, 0.5, 2 and 8mg/kg body weight) for two weeks and examined the effects on expression of liver proteins using label-free quantitative proteomics. Label-free liquid chromatography-mass spectrometry analysis of the liver proteome resulted in the quantification of 1272 proteins, of which 78 proteins were differentially regulated in the PCB 153-treated dose groups compared to the control group. Functional enrichment analysis showed that pathways significantly affected are related to lipid metabolism, cytoskeletal remodeling, cell cycle and cell adhesion. Importantly, the main effects appear to be on lipid metabolism, with up-regulation of enzymes in the de novo fatty acid synthesis pathway, consistent with previous transcriptomics results. Increased plasma triglyceride levels were also observed in the PCB 153 treated fish, in agreement with the induction of the lipogenic genes and proteins. The results suggest that PCB 153 perturbs lipid metabolism in the Atlantic cod liver. Elevated levels of lipogenic enzymes and plasma triglycerides further suggest increased synthesis of fatty acids and triglycerides. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of the Pathogenic Mutation A117V and the Protective Mutation H111S on the Folding and Aggregation of PrP106-126: Insights from Replica Exchange Molecular Dynamics Simulations.

Directory of Open Access Journals (Sweden)

Lulu Ning

Full Text Available The fragment 106-126 of prion protein exhibits similar properties to full-length prion. Experiments have shown that the A117V mutation enhances the aggregation of PrP106-126, while the H111S mutation abolishes the assembly. However, the mechanism of the change in the aggregation behavior of PrP106-126 upon the two mutations is not fully understood. In this study, replica exchange molecular dynamics simulations were performed to investigate the conformational ensemble of the WT PrP106-126 and its two mutants A117V and H111S. The obtained results indicate that the three species are all intrinsically disordered but they have distinct morphological differences. The A117V mutant has a higher propensity to form β-hairpin structures than the WT, while the H111S mutant has a higher population of helical structures. Furthermore, the A117V mutation increases the hydrophobic solvent accessible surface areas of PrP106-126 and the H111S mutation reduces the exposure of hydrophobic residues. It can be concluded that the difference in populations of β-hairpin structures and the change of hydrophobic solvent accessible areas may induce the different aggregation behaviors of the A117V and the H111S mutated PrP106-126. Understanding why the two mutations have contrary effects on the aggregation of PrP106-126 is very meaningful for further elucidation of the mechanism underlying aggregation and design of inhibitor against aggregation process.

7 CFR 12.6 - Administration.

Science.gov (United States)

2010-01-01

... 7 Agriculture 1 2010-01-01 2010-01-01 false Administration. 12.6 Section 12.6 Agriculture Office....6 Administration. (a) General. A determination of ineligibility for benefits in accordance with the... making such determinations, as provided in this section. (b) Administration by FSA. (1) The provisions of...

Enhanced desorption of PCB and trace metal elements (Pb and Cu) from contaminated soils by saponin and EDDS mixed solution

International Nuclear Information System (INIS)

Cao, Menghua; Hu, Yuan; Sun, Qian; Wang, Linling; Chen, Jing; Lu, Xiaohua

2013-01-01

This study investigated the simultaneous desorption of trace metal elements and polychlorinated biphenyl (PCB) from mixed contaminated soil with a novel combination of biosurfactant saponin and biodegradable chelant S,S-ethylenediaminedisuccinic acid (EDDS). Results showed significant promotion and synergy on Pb, Cu and PCB desorption with the mixed solution of saponin and EDDS. The maximal desorption of Pb, Cu and PCB were achieved 99.8%, 85.7% and 45.7%, respectively, by addition of 10 mM EDDS and 3000 mg L −1 saponin. The marked interaction between EDDS and saponin contributed to the synergy performance. The sorption of EDDS and saponin on soil was inhibited by each other. EDDS could enhance the complexation of metals with the saponin micelles and the solubilization capabilities of saponin micelles for PCB. Our study suggests the combination of saponin and EDDS would be a promising alternative for remediation of co-contaminated soils caused by hydrophobic organic compounds (HOCs) and metals. -- Highlights: ► A novel combination of biosurfactant saponin and EDDS was used to simultaneously remove mixed contaminations from soil. ► Significant synergy on Pb, Cu and PCB desorption were achieved with EDDS/saponin. ► The marked interaction between EDDS and saponin contributed to the synergy performance. -- Significant synergistic effect on Pb, Cu and PCB desorption were achieved with the mixed solution of saponin and EDDS

Computerization of the Electronic Scheme Drawing Equipment on Printed-Circuit-Board (PCB) Surface (Phase One)

International Nuclear Information System (INIS)

Abdul Hafid; Pinitoyo, A.; Demon H; Kussigit S; Paidjo; Riswan Dj; Natsir, M.; Dedy H; Edy Karyanta; Edy S

2003-01-01

To increase the capability of the PCB immersion machine developed previous a computerized drawing machine on PCB surface is proposed for drawing the schematic electronic, PROTEL software is used Used is Roland DXY 1100 type which had been modified to accommodate the PCB characteristic, because it is used originally for paper. Concerning, the plotter ink, the waterproof type must be used. (author)

Compound- and sex-specific effects on programming of energy and immune homeostasis in adult C57BL/6JxFVB mice after perinatal TCDD and PCB 153

Energy Technology Data Exchange (ETDEWEB)

Esterik, J.C.J. van, E-mail: joantine.van.esterik@rivm.nl [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Department of Chemistry and Biology, Institute for Environmental Studies (IVM), VU University, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Verharen, H.W., E-mail: henny.verharen@rivm.nl [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Hodemaekers, H.M., E-mail: hennie.hodemaekers@rivm.nl [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Gremmer, E.R., E-mail: eric.gremmer@rivm.nl [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Nagarajah, B., E-mail: bhawani.nagarajah@rivm.nl [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Kamstra, J.H., E-mail: jorke.kamstra@vu.nl [Department of Chemistry and Biology, Institute for Environmental Studies (IVM), VU University, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Dollé, M.E.T., E-mail: martijn.dolle@rivm.nl [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Legler, J., E-mail: juliette.legler@vu.nl [Department of Chemistry and Biology, Institute for Environmental Studies (IVM), VU University, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Ven, L.T.M. van der, E-mail: leo.van.der.ven@rivm.nl [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands)

2015-12-01

Early life exposure to endocrine disrupting compounds has been linked to chronic diseases later in life, like obesity and related metabolic disorders. We exposed C57BL/6JxFVB hybrid mice to the aryl hydrocarbon receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the constitutive androstane receptor/pregnane X receptor agonist polychlorinated biphenyl 153 (PCB 153) in an experimental design relevant for human exposure. Exposure occurred during gestation and lactation via maternal feed to a wide dose range (TCDD: 10–10,000 pg/kg body weight/day; PCB 153: 0.09–1406 μg/kg body weight/d). Then exposure was ceased and offspring were followed up to 1 year of age. Metabolic parameters like body weight, fat pad weights, glucose tolerance, endocrine serum profile, and neurobehavioral and immunological parameters were determined. Body weight was transiently affected by both compounds throughout the follow-up. TCDD-exposed males showed decreased fat pad and spleen weights and an increase in IL-4 production of splenic immune cells. In contrast, females showed increased fat pad weights and production of IFNγ. PCB 153-exposed males showed an increase in glucose, whereas females showed an increase in glucagon, a decrease in pancreas weight, and an increase in thymus weight. In conclusion, early life exposure to TCDD appears to affect programming of energy and immune homeostasis in offspring, whereas the effects of perinatal PCB 153 were mainly on programming of glucose homeostasis. Both compounds act sex-specifically. Lowest derived BMDLs (lower bounds of the (two sided) 90%-confidence interval for the benchmark dose) for both compounds are not lower than current tolerable daily intakes. - Highlights: • Early life exposure to TCDD affects programming of energy and immune homeostasis. • Early life exposure to PCB 153 affects programming of energy homeostasis. • Both compounds act sex-specifically. • Lowest derived BMDLs for both TCDD and PCB 153 are not

Compound- and sex-specific effects on programming of energy and immune homeostasis in adult C57BL/6JxFVB mice after perinatal TCDD and PCB 153

International Nuclear Information System (INIS)

Esterik, J.C.J. van; Verharen, H.W.; Hodemaekers, H.M.; Gremmer, E.R.; Nagarajah, B.; Kamstra, J.H.; Dollé, M.E.T.; Legler, J.; Ven, L.T.M. van der

2015-01-01

Early life exposure to endocrine disrupting compounds has been linked to chronic diseases later in life, like obesity and related metabolic disorders. We exposed C57BL/6JxFVB hybrid mice to the aryl hydrocarbon receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the constitutive androstane receptor/pregnane X receptor agonist polychlorinated biphenyl 153 (PCB 153) in an experimental design relevant for human exposure. Exposure occurred during gestation and lactation via maternal feed to a wide dose range (TCDD: 10–10,000 pg/kg body weight/day; PCB 153: 0.09–1406 μg/kg body weight/d). Then exposure was ceased and offspring were followed up to 1 year of age. Metabolic parameters like body weight, fat pad weights, glucose tolerance, endocrine serum profile, and neurobehavioral and immunological parameters were determined. Body weight was transiently affected by both compounds throughout the follow-up. TCDD-exposed males showed decreased fat pad and spleen weights and an increase in IL-4 production of splenic immune cells. In contrast, females showed increased fat pad weights and production of IFNγ. PCB 153-exposed males showed an increase in glucose, whereas females showed an increase in glucagon, a decrease in pancreas weight, and an increase in thymus weight. In conclusion, early life exposure to TCDD appears to affect programming of energy and immune homeostasis in offspring, whereas the effects of perinatal PCB 153 were mainly on programming of glucose homeostasis. Both compounds act sex-specifically. Lowest derived BMDLs (lower bounds of the (two sided) 90%-confidence interval for the benchmark dose) for both compounds are not lower than current tolerable daily intakes. - Highlights: • Early life exposure to TCDD affects programming of energy and immune homeostasis. • Early life exposure to PCB 153 affects programming of energy homeostasis. • Both compounds act sex-specifically. • Lowest derived BMDLs for both TCDD and PCB 153 are not

PCB and Dioxin content of Swedish waste fuels; PCB- och dioxininnehaall i svenska avfallsbraenslen

Energy Technology Data Exchange (ETDEWEB)

Blomqvist, Evalena (Swedish National Testing and Research Inst., Boraas (Sweden)) (and others)

2009-06-15

Reported dioxin data in the literature presents a rather large variation, 1-255 ng I-TEQ/kg, among different municipal solid waste (MSW) mixture samples taken within different countries. However the variation is not only large between different countries, a significant variation is reported within each study as well. Results that shows the importance of using reliable and representative sampling methods. The majority of the reported dioxin levels is within 4 to 45 ng I-TEQ/kg waste. In some of the reported studies the dioxin content has as well been analysed in sources-sorted fractions. The majority, 90-95%, of the detected dioxins were found in the fraction consisting of textiles and leather. This study aims to analyse the amount and variations, of the toxic dioxin and PCB congeners within a typical MSW mixture in Sweden, before it is energy recovered in a waste incineration plant. The study includes 20 samples, taken from two different plants in Sweden i.e. Renova and Boraas Energi och Miljoe, during 2007/2008. A well evaluated sampling method were used at both plants to achieve representative samples. Each sampling campaign resulted in a 30 kg sample that was transported in sealed containers to a laboratory. The heat value and a complete determination of the elementary content was analysed as well as the levels of toxic dioxins and PCBs in all samples. All results, both organic and inorganic, were rather similar between the two incineration plants. The resemblance within the results is an outcome of that good and representative sampling method has been used during the sampling campaigns. The average value (+/- standard deviation) of all 20 samples is 29 +/-15 ng I-TEQ per kilo of dry MSW. An average value which is within the lower range of the previous reported levels in the literature. The lower dioxin content within Swedish MSW mixtures is most likely due to the relative well-controlled waste management and sorting system in Sweden. The majority of the

Polychlorinated Biphenyl Sources, Emissions, and Environmental Levels in school Buildings (PCB Workshop presentation)

Science.gov (United States)

Measure PCB emission rates from primary sources in laboratory chambersMeasure transport and sorption by materials and dust in laboratory chambersCharacterize PCBs in school building materialsEstimate PCB emission rates from sources in schoolsExamine congener patterns in sources a...

Hepatic metabolism affects the atropselective disposition of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) in mice.

Science.gov (United States)

Wu, Xianai; Barnhart, Christopher; Lein, Pamela J; Lehmler, Hans-Joachim

2015-01-06

To understand the role of hepatic vs extrahepatic metabolism in the disposition of chiral PCBs, we studied the disposition of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) and its hydroxylated metabolites (HO-PCBs) in mice with defective hepatic metabolism due to the liver-specific deletion of cytochrome P450 oxidoreductase (KO mice). Female KO and congenic wild type (WT) mice were treated with racemic PCB 136, and levels and chiral signatures of PCB 136 and HO-PCBs were determined in tissues and excreta 3 days after PCB administration. PCB 136 tissue levels were higher in KO compared to WT mice. Feces was a major route of PCB metabolite excretion, with 2,2',3,3',6,6'-hexachlorobiphenyl-5-ol being the major metabolite recovered from feces. (+)-PCB 136, the second eluting PCB 136 atropisomers, was enriched in all tissues and excreta. The second eluting atropisomers of the HO-PCBs metabolites were enriched in blood and liver; 2,2',3,3',6,6'-hexachlorobiphenyl-5-ol in blood was an exception and displayed an enrichment of the first eluting atropisomers. Fecal HO-PCB levels and chiral signatures changed with time and differed between KO and WT mice, with larger HO-PCB enantiomeric fractions in WT compared to KO mice. Our results demonstrate that hepatic and, possibly, extrahepatic cytochrome P450 (P450) enzymes play a role in the disposition of PCBs.

Idaho National Laboratory PCB Annual Document Log and Annual Records Report for calendar year 2014

Energy Technology Data Exchange (ETDEWEB)

Layton, Deborah L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-06-01

The requirements for the reporting of polychlorinated biphenyl (PCB)-related activities are found in 40 Code of Federal Regulations (CFR) 761 Subpart J, "General Records and Reports." The PCB Annual Document Log is a detailed record of the PCB waste handling activities at the facility. The facility must prepare it each year by July 1 and maintain it at the facility for at least 3 years after the facility ceases using or storing PCBs and PCB items. While submittal of the PCB Annual Document Log to the U.S. Environmental Protection Agency (EPA) is not required by regulation, EPA has verbally requested in telephone conversations that this report be submitted to them on an annual basis. The Annual Records are not required to be submitted to EPA and are not considered to be part of the Annual Document Log, but are included to provide the complete disposition history or status of all PCB activities during the year. The Annual Document Log section of this report (Section 2.0) meets the requirements of 40 CFR 761.180(a)(2), as applicable, while the Annual Records section (Section 3.0) meets the requirement of 40 CFR 761.180(a)(1).

Idaho National Laboratory PCB Annual Document Log and Annual Records Report for Calendar Year 2013

Energy Technology Data Exchange (ETDEWEB)

no name on report

2014-06-01

The requirements for the reporting of polychlorinated biphenyl (PCB)-related activities are found in 40 Code of Federal Regulations (CFR) 761 Subpart J, "General Records and Reports." The PCB Annual Document Log is a detailed record of the PCB waste handling activities at the facility. The facility must prepare it each year by July 1 and maintain it at the facility for at least 3 years after the facility ceases using or storing PCBs and PCB items. While submittal of the PCB Annual Document Log to the U.S. Environmental Protection Agency (EPA) is not required by regulation, EPA has verbally requested in telephone conversations that this report be submitted to them on an annual basis. The Annual Document Log section of this report meets the requirements of 40 CFR 761.180(a)(2), as applicable, while the Annual Records section meets the requirement of 40 CFR 761.180(a)(1).

Contamination by polychlorinated biphenyls (PCBs) in striped dolphins (Stenella coeruleoalba) from the Southeastern Mediterranean Sea.

Science.gov (United States)

Storelli, Maria Maddalena; Barone, Grazia; Giacominelli-Stuffler, Roberto; Marcotrigiano, Giuseppe Onofrio

2012-09-01

Concentrations of polychlorinated biphenyls (PCBs) including dioxin-like PCBs (non-ortho, PCB 77, PCB 126, and PCB 169 and mono-ortho, PCB 105, PCB 118, and PCB 156) were measured in different organs and tissues (melon, blubber, liver, kidney, lung, heart, and muscle tissue) of striped dolphins (Stenella coeruleoalba) from the Eastern Mediterranean Sea (Adriatic Sea). The mean highest levels were in blubber and melon, followed by liver, kidney, lung, heart, and muscle tissue. PCB profiles were similar in all tissues and organs being dominated by the higher chlorinated homologues (hexa-CBs, 55.8-62.1%; penta-CBs, 15.4-20.0%; and hepta-CB PCB 180, 12.7-16.5%). Major PCBs in all tissues were congeners 138 and 153 collectively accounting for 50.6-58.3% of the total PCB concentrations, followed by PCB 101, 105, 118, and 180 constituting from 27.0% to 31.0%. PCB levels were higher in adult males than in adult females. The estimated 2,3,7,8-TCDD toxic equivalents of non- and mono-ortho PCBs were much higher than the threshold level above which adverse effects have been observed in other marine mammals species, suggesting that striped dolphins in this region are at risk for toxic effects.

SEASONAL INFLUENCES ON PCB RETENTION AND BIOTRANSFORMATION IN FISH

Science.gov (United States)

James, Margaret O.; Kleinow, Kevin M.

2013-01-01

There is extensive evidence that fish from waters with PCB-contaminated sediments accumulate PCBs and related chemicals, and that people who eat fish from contaminated waters have higher body burdens of PCBs and PCB metabolites than those who do not. PCBs and their metabolites are potentially toxic, thus it is important to human health to understand the uptake, biotransformation and elimination of PCBs in fish, since these processes determine the extent of accumulation. The intestinal uptake of PCBs present in the diet of fish into fish tissues is a process that is influenced by the lipid composition of the diet. Biotransformation of PCBs in fish, as in mammals, facilitates elimination, although many PCB congeners are recalcitrant to biotransformation in fish and mammals. Sequential biotransformation of PCBs by cytochrome P450 and conjugation pathways is even less efficient in fish than in mammalian species, thus contributing to the retention of PCBs in fish tissues. A very important factor influencing overall PCB disposition in fish is water temperature. Seasonal changes in water temperature produce adaptive physiological and biochemical changes in fish. While uptake of PCBs from the diet is similar in fish acclimated to winter or summer temperatures, there is evidence that elimination of PCBs occurs much more slowly when the fish is acclimated at low temperatures than at warmer temperatures. Research to date suggests that the processes of elimination of PCBs are modulated by several factors in fish including seasonal changes in water temperature. Thus, the body burden of PCBs in fish from a contaminated location is likely to vary with season. PMID:23494683

Modelling PCB bioaccumulation in a Baltic food web

International Nuclear Information System (INIS)

Nfon, Erick; Cousins, Ian T.

2007-01-01

A steady state model is developed to describe the bioaccumulation of organic contaminants by 14 species in a Baltic food web including pelagic and benthic aquatic organisms. The model is used to study the bioaccumulation of five PCB congeners of different chlorination levels. The model predictions are evaluated against monitoring data for five of the species in the food web. Predicted concentrations are on average within a factor of two of measured concentrations. The model shows that all PCB congeners were biomagnified in the food web, which is consistent with observations. Sensitivity analysis reveals that the single most sensitive parameter is log K OW . The most sensitive environmental parameter is the annual average temperature. Although not identified amongst the most sensitive input parameters, the dissolved concentration in water is believed to be important because of the uncertainty in its determination. The most sensitive organism-specific input parameters are the fractional respiration of species from the water column and sediment pore water, which are also difficult to determine. Parameters such as feeding rate, growth rate and lipid content of organism are only important at higher trophic levels. - The bioaccumulation behaviour of PCB congeners in a Baltic food web is studied using a novel mechanistic model

Biological treatment processes for PCB contaminated soil at a site in Newfoundland

International Nuclear Information System (INIS)

Punt, M.; Cooper, D.; Velicogna, D.; Mohn, W.; Reimer, K.; Parsons, D.; Patel, T.; Daugulis, A.

2002-01-01

SAIC Canada is conducting a study under the direction of a joint research and development contract between Public Works and Government Services Canada and Environment Canada to examine the biological options for treating PCB contaminated soil found at a containment cell at a former U.S. Military Base near Stephenville, Newfoundland. In particular, the study examines the feasibility of using indigenous microbes for the degradation of PCBs. The first phase of the study involved the testing of the microbes in a bioreactor. The second phase, currently underway, involves a complete evaluation of possible microbes for PCB degradation. It also involves further study into the biological process options for the site. Suitable indigenous and non-indigenous microbes for PCB dechlorination and biphenyl degradation are being identified and evaluated. In addition, the effectiveness and economics of microbial treatment in a conventional bioreactor is being evaluated. The conventional bioreactor used in this study is the two-phase partitioning bioreactor (TPPB) using a biopile process. Results thus far will be used to help Public Works and Government Services Canada to choose the most appropriate remedial technology. Preliminary results suggest that the use of soil classification could reduce the volume of soil requiring treatment. The soil in the containment cell contains microorganisms that could grow in isolation on biphenyl, naphthalene and potentially Aroclor 1254. Isolated native microbes were inoculated in the TPPB for growth. The TPPB was also run successfully under anaerobic conditions. Future work will involve lab-scale evaluation of microbes for PCB dechlorination and biphenyl degradation using both indigenous and non-indigenous microbes. The next phase of study may also involve field-scale demonstration of treatment methods. 2 refs., 3 tabs., 5 figs

A highly sensitive and selective aptamer-based colorimetric sensor for the rapid detection of PCB 77.

Science.gov (United States)

Cheng, Ruojie; Liu, Siyao; Shi, Huijie; Zhao, Guohua

2018-01-05

A highly sensitive, specific and simple colorimetric sensor based on aptamer was established for the detection of polychlorinated biphenyls (PCB 77). The use of unmodified gold nanoparticles as a colorimetric probe for aptamer sensors enabled the highly sensitive and selective detection of polychlorinated biphenyls (PCB 77). A linear range of 0.5nM to 900nM was obtained for the colorimetric assay with a minimum detection limit of 0.05nM. In addition, by the methods of circular dichroism, UV and naked eyes, we found that the 35 base fragments retained after cutting 5 bases from the 5 'end of aptamer plays the most significant role in the PCB 77 specific recognition process. We found a novel way to truncated nucleotides to optimize the detection of PCB 77, and the selected nucleotides also could achieve high affinity with PCB 77. At the same time, the efficient detection of the PCB 77 by our colorimetric sensor in the complex environmental water samples was realized, which shows a good application prospect. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of a combination of two tetrachlorobiphenyl congeners (PCB 47; PCB 77) on thyroid status, choline acetyltransferase (ChAT) activity, and short- and long-term memory in 30-day-old Sprague-Dawley rats

International Nuclear Information System (INIS)

Donahue, Douglas A.; Dougherty, Edward J.; Meserve, Lee A.

2004-01-01

The important role of thyroid hormones in growth and development, maintenance of body temperature, digestion, cardiac function, and normal brain development can be disrupted by environmental contaminants like polychlorinated biphenyls (PCB). Polychlorinated biphenyls are environmental contaminants that are widespread, persistent, lipophilic, and bioaccumulate through food webs, concentrating in adipose tissue. Placental and lactational PCB exposure of offspring causes metabolic and endocrine disruptions including hypothyroxinemia, spatial learning and memory deficits, neurochemical and neurobehavioral alterations, and reproductive problems. Previous studies in our lab using the individual congeners PCB 47 (2,2',4,4'-tetrachlorobiphenyl, ortho-substituted) and PCB 77 (3,3',4,4'-tetrachlorobiphenyl, non-ortho-substituted) have demonstrated alterations in thyroid hormone levels, alterations in brain choline acetyltransferase (ChAT) activity, and spatial learning deficits. In the present study, pregnant Sprague-Dawley rats were fed a diet with or without a mixture of PCB 47/77 at 1.25 ppm, 12.5 ppm or 25.0 ppm (w/w). Rat pups were swum in the Morris water maze four times a day on days 21-29 in order for the animals to learn the position of a submerged fixed platform. A probe test was run on day 24 (30 min after last swim) for short-term memory, and on day 29 (24 h after the last swim) for long-term memory after removal of the platform. Time spent in the quadrant previously containing the platform was recorded. Rats were decapitated on day 30, serum collected and frozen at -20 deg. ChAT activity was measured radiometrically in basal forebrain and hippocampus. All PCB-treated animals experienced a depression in both triiodothyronine (T 3 ) and thyroxine (T 4 ). The present study found that all doses of PCB depressed ChAT activity in hippocampus with no significant alteration in the basal forebrain. In PCB-treated animals, short-term memory showed a trend toward

Toxic effect of PBDE-47 on thyroid development, learning, and memory, and the interaction between PBDE-47 and PCB153 that enhances toxicity in rats.

Science.gov (United States)

He, Ping; Wang, Aiguo; Niu, Qiang; Guo, Lijuan; Xia, Tao; Chen, Xuemin

2011-04-01

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are widespread environmental contaminants. There are potential interactive effects between PBDEs and PCBs, as these compounds share similar structures. The developmental neurotoxicity of 2, 2', 4, 4'-tetrabromodiphenyl ether (PBDE-47) and the interaction of PBDE-47 with 2, 2', 4, 4', 5, 5'-hexachlorobipheny (PCB153) were investigated herein, as the dominant congener forms of PBDEs and PCBs, respectively. SD rats were exposed to a single oral dose of PBDE-47 (1, 5, and 10 μg/g) and/or PCB153 (5 μg/g) on post-natal day (PND) 10. Concentrations of PBDE-47, triiodothyronine (T(3)), thyroxine (T(4)), and thyroid-stimulating hormone (TSH) in serum; organ-to-body weight ratios; as well as long-term learning and memory were measured in 2-month-old rats. The present study found that some doses of PBDE-47 decreased the organ-to-body weight ratios of the thyroid and uterus, decreased the concentration of T(4) in serum, and increased the organ-to-body weight ratio of the ovaries (p action of PBDE-47 during combined exposure, but this interaction was not found between PBDE-47 and PCB153. In a Morris water maze experiment, the latency periods were significantly prolonged and time ratios were obviously depressed in all PBDE-47-treated groups compared to the control (p memory capabilities in adult rats exposed to PBDE-47 on PND 10. PCB153 can interact with PBDE-47, resulting in an increase in developmental neurotoxicity.

7 CFR 1710.126 - Federal debt delinquency.

Science.gov (United States)

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Federal debt delinquency. 1710.126 Section 1710.126... and Basic Policies § 1710.126 Federal debt delinquency. (a) Prior to approval of a loan or advance of... reasons for the delinquency must be explained, and RUS will take such explanation into consideration in...

Mango Polyphenolics Reduce Inflammation in Intestinal Colitis—Involvement of the miR-126/PI3K/AKT/mTOR Axis In Vitro and In Vivo

Science.gov (United States)

Kim, Hyemee; Banerjee, Nivedita; Barnes, Ryan C.; Pfent, Catherine M.; Talcott, Stephen T.; Dashwood, Roderick H.; Mertens-Talcott, Susanne U.

2016-01-01

This study sought to elucidate the mechanisms underlying the anti-inflammatory effect of mango (Mangifera Indica L.) polyphenolics containing gallic acid and gallotanins, and the role of the miR-126/PI3K/AKT/mTOR signaling axis in vitro and in vivo. Polyphenolics extracted from mango (var. Keitt) were investigated in lipopolysaccharide (LPS)-treated CCD-18Co cells. Rats received either a beverage with mango polyphenolics or a control beverage, and were exposed to three cycles of 3% dextran sodium sulfate (DSS) followed by a 2-wk recovery period. The mango extract (10 mg GAE/L) suppressed the protein expression of NF-κB, p-NF-κB, PI3K (p85β), HIF-1α, p70S6K1, and RPS6 in LPS-treated CCD-18Co cells. LPS reduced miR-126 expression, whereas, the mango extract induced miR-126 expression in a dose-dependent manner. The relationship between miR-126 and its target, PI3K (p85β), was confirmed by treating cells with miR-126 antagomiR where mango polyphenols reversed the effects of the antagomiR. In vivo, mango beverage protected against DSS-induced colonic inflammation (47%, P = 0.05) and decreased the Ki-67 labeling index in the central and basal regions compared to the control. Mango beverage significantly attenuated the expression of pro-inflammatory cytokines such as TNF-α, IL-1β, and iNOS at the mRNA and protein level. Moreover, the expression of PI3K, AKT, and mTOR was reduced, whereas, miR-126 was upregulated by the mango treatment. These results suggest that mango polyphenols attenuated inflammatory response by modulating the PI3K/AKT/mTOR pathway at least in part through upregulation of miRNA-126 expression both in vitro and in vivo; thus, mango polyphenolics might be relevant as preventive agents in ulcerative colitis. PMID:27061150

Polychlorinated biphenyl quinone induces oxidative DNA damage and repair responses: The activations of NHEJ, BER and NER via ATM-p53 signaling axis

Energy Technology Data Exchange (ETDEWEB)

Dong, Hui; Shi, Qiong; Song, Xiufang; Fu, Juanli; Hu, Lihua; Xu, Demei; Su, Chuanyang; Xia, Xiaomin; Song, Erqun; Song, Yang, E-mail: songyangwenrong@hotmail.com

2015-07-01

Our previous studies demonstrated that polychlorinated biphenyl (PCB) quinone induced oxidative DNA damage in HepG2 cells. To promote genomic integrity, DNA damage response (DDR) coordinates cell-cycle transitions, DNA repair and apoptosis. PCB quinone-induced cell cycle arrest and apoptosis have been documented, however, whether PCB quinone insult induce DNA repair signaling is still unknown. In this study, we identified the activation of DDR and corresponding signaling events in HepG2 cells upon the exposure to a synthetic PCB quinone, PCB29-pQ. Our data illustrated that PCB29-pQ induces the phosphorylation of p53, which was mediated by ataxia telangiectasia mutated (ATM) protein kinase. The observed phosphorylated histone H2AX (γ-H2AX) foci and the elevation of 8-hydroxy-2′-deoxyguanosine (8-OHdG) indicated that DDR was stimulated by PCB29-pQ treatment. Additionally, we found PCB29-pQ activates non-homologous end joining (NHEJ), base excision repair (BER) and nucleotide excision repair (NER) signalings. However, these repair pathways are not error-free processes and aberrant repair of DNA damage may cause the potential risk of carcinogenesis and mutagenesis. - Highlights: • Polychlorinated biphenyl quinone induces oxidative DNA damage in HepG2 cells. • The elevation of γ-H2AX and 8-OHdG indicates the activation of DNA damage response. • ATM-p53 signaling acts as the DNA damage sensor and effector. • Polychlorinated biphenyl quinone activates NHEJ, BER and NER signalings.

PCB153 reduces telomerase activity and telomere length in immortalized human skin keratinocytes (HaCaT) but not in human foreskin keratinocytes (NFK)

International Nuclear Information System (INIS)

Senthilkumar, P.K.; Robertson, L.W.; Ludewig, G.

2012-01-01

Polychlorinated biphenyls (PCBs), ubiquitous environmental pollutants, are characterized by long term-persistence in the environment, bioaccumulation, and biomagnification in the food chain. Exposure to PCBs may cause various diseases, affecting many cellular processes. Deregulation of the telomerase and the telomere complex leads to several biological disorders. We investigated the hypothesis that PCB153 modulates telomerase activity, telomeres and reactive oxygen species resulting in the deregulation of cell growth. Exponentially growing immortal human skin keratinocytes (HaCaT) and normal human foreskin keratinocytes (NFK) were incubated with PCB153 for 48 and 24 days, respectively, and telomerase activity, telomere length, superoxide level, cell growth, and cell cycle distribution were determined. In HaCaT cells exposure to PCB153 significantly reduced telomerase activity, telomere length, cell growth and increased intracellular superoxide levels from day 6 to day 48, suggesting that superoxide may be one of the factors regulating telomerase activity, telomere length and cell growth compared to untreated control cells. Results with NFK cells showed no shortening of telomere length but reduced cell growth and increased superoxide levels in PCB153-treated cells compared to untreated controls. As expected, basal levels of telomerase activity were almost undetectable, which made a quantitative comparison of treated and control groups impossible. The significant down regulation of telomerase activity and reduction of telomere length by PCB153 in HaCaT cells suggest that any cell type with significant telomerase activity, like stem cells, may be at risk of premature telomere shortening with potential adverse health effects for the affected organism. -- Highlights: ► Human immortal (HaCaT) and primary (NFK) keratinocytes were exposed to PCB153. ► PCB153 significantly reduced telomerase activity and telomere length in HaCaT. ► No effect on telomere length and

Investigating Intergenerational Differences in Human PCB Exposure due to Variable Emissions and Reproductive Behaviors

Science.gov (United States)

Quinn, Cristina L.; Wania, Frank; Czub, Gertje; Breivik, Knut

2011-01-01

Background Reproductive behaviors—such as age of childbearing, parity, and breast-feeding prevalence—have changed over the same historical time period as emissions of polychlorinated biphenyls (PCB) and may produce intergenerational differences in human PCB exposure. Objectives Our goal in this study was to estimate prenatal, postnatal, and lifetime PCB exposures for women at different ages according to year of birth, and to evaluate the impact of reproductive characteristics on intergenerational differences in exposure. Methods We used the time-variant mechanistic model CoZMoMAN to calculate human bioaccumulation of PCBs, assuming both hypothetical constant and realistic time-variant emissions. Results Although exposure primarily depends on when an individual was born relative to the emission history of PCBs, reproductive behaviors can have a significant impact. Our model suggests that a mother’s reproductive history has a greater influence on the prenatal and postnatal exposures of her children than it does on her own cumulative lifetime exposure. In particular, a child’s birth order appears to have a strong influence on their prenatal exposure, whereas postnatal exposure is determined by the type of milk (formula or breast milk) fed to the infant. Conclusions Prenatal PCB exposure appears to be delayed relative to the time of PCB emissions, particularly among those born after the PCB production phaseout. Consequently, the health repercussions of environmental PCBs can be expected to persist for several decades, despite bans on their production for > 40 years. PMID:21156396

Polyphenolic extracts from cowpea (Vigna unguiculata) protect colonic myofibroblasts (CCD18Co cells) from lipopolysaccharide (LPS)-induced inflammation--modulation of microRNA 126.

Science.gov (United States)

Ojwang, Leonnard O; Banerjee, Nivedita; Noratto, Giuliana D; Angel-Morales, Gabriela; Hachibamba, Twambo; Awika, Joseph M; Mertens-Talcott, Susanne U

2015-01-01

Cowpea (Vigna unguiculata) is a drought tolerant crop with several agronomic advantages over other legumes. This study evaluated varieties from four major cowpea phenotypes (black, red, light brown and white) containing different phenolic profiles for their anti-inflammatory property on non-malignant colonic myofibroblasts (CCD18Co) cells challenged with an endotoxin (lipopolysaccharide, LPS). Intracellular reactive oxygen species (ROS) assay on the LPS-stimulated cells revealed antioxidative potential of black and red cowpea varieties. Real-time qRT-PCR analysis in LPS-stimulated cells revealed down-regulation of proinflammatory cytokines (IL-8, TNF-α, VCAM-1), transcription factor NF-κB and modulation of microRNA-126 (specific post-transcriptional regulator of VCAM-1) by cowpea polyphenolics. The ability of cowpea polyphenols to modulate miR-126 signaling and its target gene VCAM-1 were studied in LPS-stimulated endothelial cells transfected with a specific inhibitor of miR-126, and treated with 10 mg GAE/L black cowpea extract where the extract in part reversed the effect of the miR-126 inhibitor. This suggests that cowpea may exert their anti-inflammatory activities at least in part through induction of miR-126 that then down-regulate VCAM-1 mRNA and protein expressions. Overall, Cowpea therefore is promising as an anti-inflammatory dietary component.

Editor's Highlight: Congener-Specific Disposition of Chiral Polychlorinated Biphenyls in Lactating Mice and Their Offspring: Implications for PCB Developmental Neurotoxicity.

Science.gov (United States)

Kania-Korwel, Izabela; Lukasiewicz, Tracy; Barnhart, Christopher D; Stamou, Marianna; Chung, Haeun; Kelly, Kevin M; Bandiera, Stelvio; Lein, Pamela J; Lehmler, Hans-Joachim

2017-07-01

Chiral polychlorinated biphenyl (PCB) congeners have been implicated by laboratory and epidemiological studies in PCB developmental neurotoxicity. These congeners are metabolized by cytochrome P450 (P450) enzymes to potentially neurotoxic hydroxylated metabolites (OH-PCBs). The present study explores the enantioselective disposition and toxicity of 2 environmentally relevant, neurotoxic PCB congeners and their OH-PCB metabolites in lactating mice and their offspring following dietary exposure of the dam. Female C57BL/6N mice (8-weeks old) were fed daily, beginning 2 weeks prior to conception and continuing throughout gestation and lactation, with 3.1 µmol/kg bw/d of racemic 2,2',3,5',6-pentachlorobiphenyl (PCB 95) or 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) in peanut butter; controls received vehicle (peanut oil) in peanut butter. PCB 95 levels were higher than PCB 136 levels in both dams and pups, consistent with the more rapid metabolism of PCB 136 compared with PCB 95. In pups and dams, both congeners were enriched for the enantiomer eluting second on enantioselective gas chromatography columns. OH-PCB profiles in lactating mice and their offspring were complex and varied according to congener, tissue and age. Developmental exposure to PCB 95 versus PCB 136 differentially affected the expression of P450 enzymes as well as neural plasticity (arc and ppp1r9b) and thyroid hormone-responsive genes (nrgn and mbp). The results suggest that the enantioselective metabolism of PCBs to OH-PCBs may influence neurotoxic outcomes following developmental exposures, a hypothesis that warrants further investigation. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

PCB and PAH release from power stations and waste incineration processes in the UK

Energy Technology Data Exchange (ETDEWEB)

Dyke, Patrick H. [PD Consulting, Magdalen, Brobury, HR3 6DX (United Kingdom); Foan, Colin [The Environment Agency, National Centre for Risk Analysis and Options Appraisal, Kings Meadow House, Kings Meadow Road, Reading, (United Kingdom); Fiedler, Heidelore [United Nations Environment Programme (UNEP) Chemicals, 11-13, chemin des Anemones, CH-1219, Chatelaine (Switzerland)

2003-01-01

This study focused on emissions of polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) from incineration and power generation processes. Increased concern over human exposure to both classes of compounds has meant that environmental regulators need to assess the contribution made by emissions from regulated processes to human exposure. In the first part of an assessment in the UK we reviewed literature data on emissions of PCB, focusing on the dioxin-like PCB assigned toxic equivalency factors by the World Health Organization, and PAH. The literature study was supplemented by a series of plant tests to gather initial real plant data. Literature data were limited and the lack of standard protocols for measurement and reporting of both PCB and PAH meant that few data sets were comparable. Levels of dioxin-like PCB reported in the literature and measured in UK plant tests showed that well-controlled modern combustion plants with comprehensive pollution controls gave low emissions, typically about 5-10% of the toxic equivalent of the emissions of polychlorinated dibenzodioxins and dibenzofurans at the same plants and below the widely used standard of 0.1 ng TEQ/N m{sup 3}. (Author)

Concentration of polychlorinated biphenyl (PCB) congeners in the muscle of Clarias gariepinus and sediment from inland rivers of southwestern Nigeria and estimated potential human health consequences.

Science.gov (United States)

Adeogun, Aina O; Chukwuka, Azubuike V; Okoli, Chukwunonso P; Arukwe, Augustine

2016-01-01

The distributions of polychlorinated biphenyl (PCB) congeners were determined in sediment and muscle of the African sharptooth catfish (Clarias gariepinus) from the Ogun and Ona rivers, southwest Nigeria. In addition, the effect of PCB congeners on condition factor (CF) and associated human health risk was assessed using muscle levels for a noncarcinogenic hazard quotient (HQ) calculation. Elevated concentrations of high-molecular-weight (HMW) PCB congeners were detected in sediment and fish downstream of discharge points of both rivers. A significant reduction in fish body weight and CF was observed to correlate with high PCB congener concentrations in the Ona River. A principal component (PC) biplot revealed significant site-related PCB congener distribution patterns for HMW PCB in samples from the Ogun River (71.3%), while the Ona River (42.6%) showed significant PCB congener patterns for low-molecular-weight (LMW) congeners. Biota-sediment accumulation factor (BSAF) was higher downstream for both rivers, presenting PCB congener-specific accumulation patterns in the Ona River. Significant decreases in fish body weight, length and CF were observed downstream compared to upstream in the Ona River. The non-carcinogenic HQ of dioxin-like congener 189 downstream in both rivers exceeded the HQ = 1 threshold for children and adults for both the Ogun and Ona rivers. Overall, our results suggest that industrial discharges contribute significantly to PCB inputs into these rivers, with potential for significant health implications for neighboring communities that utilize these rivers for fishing and other domestic purposes.

Alberta opens its borders to PCB waste from other provinces for destruction

International Nuclear Information System (INIS)

Hurst, R.

1995-01-01

The most recent and most significant development in the management of PCBs in Canada occurred with the announcement of the Alberta government that it would open its provincial borders to PCB and other hazardous wastes from across Canada for incineration at the province's special waste treatment facility located at Swan Hills, Alberta. The facility has an annual capacity of 15,000 tonnes of PCB waste. Alberta 's own waste products will be treated first; any excess capacity will be utilized to treat waste materials received from other provinces. It is estimated that given the Swan Hills plant capacity, it will take several years to treat and destroy all of Canada's current PCB waste inventory. Regulations concerning transportation, contracting requirements and pricing policies were briefly reviewed

Toxicological Profile of Ultrapure 2,2′,3,4,4′,5,5′-Heptachlorbiphenyl (PCB 180) in Adult Rats

Science.gov (United States)

Viluksela, Matti; Heikkinen, Päivi; van der Ven, Leo T. M.; Rendel, Filip; Roos, Robert; Esteban, Javier; Korkalainen, Merja; Lensu, Sanna; Miettinen, Hanna M.; Savolainen, Kari; Sankari, Satu; Lilienthal, Hellmuth; Adamsson, Annika; Toppari, Jorma; Herlin, Maria; Finnilä, Mikko; Tuukkanen, Juha; Leslie, Heather A.; Hamers, Timo; Hamscher, Gerd; Al-Anati, Lauy; Stenius, Ulla; Dervola, Kine-Susann; Bogen, Inger-Lise; Fonnum, Frode; Andersson, Patrik L.; Schrenk, Dieter; Halldin, Krister; Håkansson, Helen

2014-01-01

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 weight gain was retarded at 1700 mg/kg during loading dosing, but recovered thereafter. The most sensitive endpoint of toxicity that was used for risk characterization was altered open field behavior in females; i.e. increased activity and distance moved in the inner zone of an open field suggesting altered emotional responses to unfamiliar environment and impaired behavioral inhibition. Other dose-dependent changes included decreased serum thyroid hormones with associated histopathological changes, altered tissue retinoid levels, decreased hematocrit and hemoglobin, decreased follicle stimulating hormone and luteinizing hormone levels in males and increased expression of DNA damage markers in liver of females. Dose-dependent hypertrophy of zona fasciculata cells was observed in adrenals suggesting activation of cortex. There were gender differences in sensitivity and toxicity profiles were partly different in males and females. PCB 180 adipose tissue concentrations were clearly above the general human population levels, but close to the levels in highly exposed populations. The results demonstrate a distinct toxicological profile of PCB 180 with lack of dioxin-like properties required for assignment of WHO toxic equivalency factor. However, PCB 180 shares several toxicological

Dose-Response of High-Intensity Training (HIT) on Atheroprotective miRNA-126 Levels

Science.gov (United States)

Schmitz, Boris; Schelleckes, Katrin; Nedele, Johanna; Thorwesten, Lothar; Klose, Andreas; Lenders, Malte; Krüger, Michael; Brand, Eva; Brand, Stefan-Martin

2017-01-01

Aim: MicroRNA-126 (miR-126) exerts beneficial effects on vascular integrity, angiogenesis, and atherosclerotic plaque stability. The purpose of this investigation was to analyze the dose-response relationship of high-intensity interval training (HIIT) on miR-126-3p and -5p levels. Methods: Sixty-one moderately trained individuals (females = 31 [50.8%]; 22.0 ± 1.84 years) were consecutively recruited and allocated into three matched groups using exercise capacity. During a 4-week intervention a HIIT group performed three exercise sessions/week of 4 × 30 s at maximum speed (all-out), a progressive HIIT (proHIIT) group performed three exercise sessions/week of 4 × 30 s at maximum speed (all-out) with one extra session every week (up to 7 × 30 s) and a low-intensity training (LIT) control group performed three exercise sessions/week for 25 min HIIT groups (after 4 min of high-intensity running). After the intervention, the LIT group presented an increase in miR-126-3p, while in the HIIT group, miR-126-3p levels were still reduced (all p HIIT (−1.05 ± 2.6 units). Conclusions: LIT and proHIIT may be performed to increase individual miR-126 levels. HIIT without progression was less effective in increasing miR-126. PMID:28611681

MicroRNA-126 deficiency enhanced the activation and function of CD4+ T cells by elevating IRS-1 pathway.

Science.gov (United States)

Chu, F; Hu, Y; Zhou, Y; Guo, M; Lu, J; Zheng, W; Xu, H; Zhao, J; Xu, L

2018-02-01

Recent evidence has shown that microRNA-126 (miR-126) has been involved in the development and function of immune cells, which contributed to the pathogenesis of related clinical diseases. However, the potential role of miR-126 in the development and function of CD4 + T cells remains largely unknown. Here we first found that the activation and proliferation, as well as the expression of interferon (IFN)-γ, of CD4 + T cells from miR-126 knock-down (KD) mice using the miRNA-sponge technique were enhanced significantly in vitro, compared with those in CD4 + T cells from wild-type (WT) mice. To monitor further the possible effect of miR-126 deficiency on the function of CD4 + T cells in vivo, we used dextran sulphate sodium (DSS)-induced murine model of acute autoimmune colitis and found that miR-126 deficiency could elevate the pathology of colitis. Importantly, the proportion of CD4 + T cells in splenocytes increased significantly in miR-126KD mice. Moreover, the expression levels of CD69 and CD44 on CD4 + T cells increased significantly and the expression level of CD62L decreased significantly. Of note, adoptive cell transfer assay showed that the pathology of colitis was more serious in carboxyfluorescein succinimidyl ester (CFSE)-labelled miR-126KD CD4 + T cell-transferred group, compared with that in the CFSE-labelled WT CD4 + T cells transferred group. Consistently, the expression levels of CD69 and CD44 on CFSE + cells increased significantly. Furthermore, both the proliferation and IFN-γ secretion of CFSE + cells also increased significantly in the CFSE-labelled miR-126KD CD4 + T cell-transferred group. Mechanistic evidence showed that the expression of insulin receptor substrate 1 (IRS-1), as a functional target of miR-126, was elevated in CD4 + T cells from miR-126KD mice, accompanied by altered transduction of the extracellular regulated kinase, protein B (AKT) and nuclear factor kappa B (NF-κB) pathway. Our data revealed a novel role in which miR-126

29 CFR 570.126 - Parental exemption.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Parental exemption. 570.126 Section 570.126 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR REGULATIONS CHILD LABOR REGULATIONS, ORDERS AND STATEMENTS OF INTERPRETATION General Statements of Interpretation of the Child Labor...

Theoretical study on production of heavy neutron-rich isotopes around the N=126 shell closure in radioactive beam induced transfer reactions

Directory of Open Access Journals (Sweden)

Long Zhu

2017-04-01

Full Text Available In order to produce more unknown neutron-rich nuclei around N=126, the transfer reactions 136Xe + 198Pt, 136–144Xe + 208Pb, and 132Sn + 208Pb are investigated within the framework of the dinuclear system (DNS model. The influence of neutron excess of projectile on production cross sections of target-like products is studied through the reactions 136,144Xe + 208Pb. We find that the radioactive projectile 144Xe with much larger neutron excess is favorable to produce neutron-rich nuclei with charge number less than the target rather than produce transtarget nuclei. The incident energy dependence of yield distributions of fragments in the reaction 132Sn + 208Pb are also studied. The production cross sections of neutron-rich nuclei with Z=72–77 are predicted in the reactions 136–144Xe + 208Pb and 132Sn + 208Pb. It is noticed that the production cross sections of unknown neutron-rich nuclei in the reaction 144Xe + 208Pb are at least two orders of magnitude larger than those in the reaction 136Xe + 208Pb. The radioactive beam induced transfer reactions 139,144Xe + 208Pb, considering beam intensities proposed in SPIRAL2 (Production System of Radioactive Ion and Acceleration On-Line project as well, for production of neutron-rich nuclei around the N=126 shell closure are investigated for the first time. It is found that, in comparison to the stable beam 136Xe, the radioactive beam 144Xe shows great advantages for producing neutron-rich nuclei with N=126 and the advantages get more obvious for producing nuclei with less charge number.

RANCANG BANGUN CNC MILLING MACHINEHOME MADE UNTUK MEMBUAT PCB

Directory of Open Access Journals (Sweden)

Dityo Pradana

2011-06-01

Full Text Available Kendala yang dimiliki oleh seorang penggemar elektronik untuk membuat PCB diantaranya adalah efisiensi waktu, tenaga, dan biaya. Pembuatan CNC milling machine merupakan salah satu solusi yang tepat untuk membuat PCB. CNC milling machine adalah mesin bubut otomatis yang bekerja atas dasar perintah Numerical Code. Rancang bangun CNC Milling Machine Home Made ini dikontrol oleh komputer yang akan mengontrol IC L297 melalui parallel port. IC L297 ini kemudian memberikan empat data digital a, b, c dan d untuk mengatur phase IC L298 yang menyalurkan tegangan untuk koil motor stepper unipolar. Pada akhirnya motor stepper unipolar akan memutar baut dan dapat menggerakkan meja sumbu menggunakan prinsip kerja ulir.

Distinguishing PCB Isomeric Congeners with their Gas Chromatographic and Mass Spectrometric Ortho Effect using Comprehensive Gas Chromatography

Science.gov (United States)

The 209 polychlorinated biphenyl (PCB) congeners and associated nine isomeric groups (nine groups of PCBs with the same degree of chlorination) have been long recorded as high endocrine disrupting chemicals in the environment. Difficult analytical problems exist, in those frequen...

Inhibition of the promotion of hepatocarcinogenesis by 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) by the deletion of the p50 subunit of NF-κB in mice

International Nuclear Information System (INIS)

Glauert, Howard P.; Tharappel, Job C.; Banerjee, Subhashis; Chan, Nelson L.S.; Kania-Korwel, Izabela; Lehmler, Hans-Joachim; Lee, Eun Y.; Robertson, Larry W.; Spear, Brett T.

2008-01-01

Polychlorinated biphenyls (PCBs) are persistent and ubiquitous environmental chemicals that bioaccumulate and have hepatic tumor promoting activity in rodents. The present study examined the effect of deleting the p50 subunit of NF-κB on the hepatic tumor promoting activity of 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) in mice. Both wild-type and p50-/- male mice were injected i.p. with diethylnitrosamine (DEN, 90 mg/kg) and then subsequently injected biweekly with 20 i.p. injections of PCB-153 (300 μmol/kg/injection). p50 deletion decreased the tumor incidence in both PCB- and vehicle-treated mice, whereas PCB-153 slightly (P = 0.09) increased the tumor incidence in wild-type and p50-/- mice. PCB-153 increased the total tumor volume in both wild-type and p50-/- mice, but the total tumor volume was not affected by p50 deletion in either PCB- or vehicle-treated mice. The volume of tumors that were positive for glutamine synthetase (GS), which is indicative of mutations in the beta-catenin gene, was increased in both wild-type and p50-/- mice administered PCB-153 compared to vehicle controls, and inhibited in p50-/- mice compared to wild-type mice (in both PCB- and vehicle-treated mice). The volume of tumors that were negative for GS was increased in p50-/- mice compared to wild-type mice but was not affected by PCB-153. PCB-153 increased cell proliferation in normal hepatocytes in wild-type but not p50-/- mice; this increase was inhibited in p50-/- mice. In hepatic tumors, the rate of cell proliferation was much higher than in normal hepatocytes, but was not affected by PCB treatment or p50 deletion. The rate of apoptosis, as measured by the TUNEL assay, was not affected by PCB-153 or p50 deletion in normal hepatocytes. In hepatic tumors, the rate of apoptosis was lower than in normal hepatocytes; PCB-153 slightly (P = 0.10) increased apoptosis in p50-/- but not wild-type mice; p50 deletion had no effect. Taken together, these data indicate that the absence of

PCDD/F and dioxin-like PCB in human blood and milk from German mothers

Energy Technology Data Exchange (ETDEWEB)

Wittsiepe, J.; Schrey, P.; Lemm, F.; Wilhelm, M. [Ruhr-Univ. Bochum, Abt. fuer Hygiene, Sozial- und Umweltmedizin (Germany); Fuerst, P. [Chemisches Landes- und Staatliches Veterinaeruntersuchungsamt, Muenster (Germany); Kraft, M. [Ministerium fuer Umwelt und Naturschutz, Landwirtschaft und Verbraucherschutz des Landes Nordrhein-Westfalen, Duesseldorf (Germany); Eberwein, G. [Landesumweltamt Nordrhein-Westfalen, Essen (Germany); Winneke, G. [Medizinisches Inst. fuer Umwelthygiene an der Heinrich-Heine Univ. Duesseldorf (Germany)

2004-09-15

Human biomonitoring of polychlorinated dibenzo-p-dioxins and dibenzofuranes (PCDD/F) and polychlorinated biphenyls (PCB) is done by analyzing both blood and milk samples. With reference to calculation of Toxicity Equivalents (TEq) as published by the World Health Organization (WHO) in 1998 determination of 17 PCDD/F congeners together with 4 non- and 8 mono-ortho PCB congeners is the preferred method. In contrast to data on PCDD/F only little is known on background levels of dioxin-like PCB in human blood or milk samples. In the present study we report on PCDD/F and PCB levels in human blood samples of pregnant women living in an industrialized area of Germany and of human milk samples from the same women taken in the first weeks after birth. The investigations demonstrate the current background levels found in Germany, make a contribution for the assessment of preand postnatal exposure of infants and show correlations between the two matrices.

Aryl hydrocarbon receptor signaling modulates antiviral immune responses: ligand metabolism rather than chemical source is the stronger predictor of outcome.

Science.gov (United States)

Boule, Lisbeth A; Burke, Catherine G; Jin, Guang-Bi; Lawrence, B Paige

2018-01-29

The aryl hydrocarbon receptor (AHR) offers a compelling target to modulate the immune system. AHR agonists alter adaptive immune responses, but the consequences differ across studies. We report here the comparison of four agents representing different sources of AHR ligands in mice infected with influenza A virus (IAV): TCDD, prototype exogenous AHR agonist; PCB126, pollutant with documented human exposure; ITE, novel pharmaceutical; and FICZ, degradation product of tryptophan. All four compounds diminished virus-specific IgM levels and increased the proportion of regulatory T cells. TCDD, PCB126 and ITE, but not FICZ, reduced virus-specific IgG levels and CD8 + T cell responses. Similarly, ITE, PCB126, and TCDD reduced Th1 and Tfh cells, whereas FICZ increased their frequency. In Cyp1a1-deficient mice, all compounds, including FICZ, reduced the response to IAV. Conditional Ahr knockout mice revealed that all four compounds require AHR within hematopoietic cells. Thus, differences in the immune response to IAV likely reflect variances in quality, magnitude, and duration of AHR signaling. This indicates that binding affinity and metabolism may be stronger predictors of immune effects than a compound's source of origin, and that harnessing AHR will require finding a balance between dampening immune-mediated pathologies and maintaining sufficient host defenses against infection.

Migration and opportunistic feeding increase PCB accumulation in Arctic seabirds.

Science.gov (United States)

Baert, J M; Janssen, C R; Borgå, K; De Laender, F

2013-10-15

It is widely accepted that body concentrations of persistent organic pollutants (POPs) tend to increase with trophic level (TL). Yet, little attention has been paid to the causes in the underlying differences in POP body concentrations between species occupying similar TLs. In this paper we use two modeling approaches to quantify the importance of migration and opportunistic feeding, relative to that of trophic level, in explaining interspecific differences in polychlorinated biphenyl (PCB) body concentrations between 6 Arctic seabird species breeding in the Barents Sea: Little Auk (Alle alle), Black Guillemot (Cepphus grylle), Brünnich's Guillemot (Uria lomvia), Common Eider (Somateria mollissima), Black-legged Kittiwake (Rissa tridactyla), and Glaucous Gull (Larus hyperboreus). As a first approach, we use additive models to analyze two independent data sets (n = 470 and n = 726). We demonstrate that migration, opportunistic feeding, and TL significantly (p < 0.001) increase PCB body concentrations by a factor 3.61-4.10, 2.66-20.95, and 2.38-2.41, respectively. Our second approach, using a mechanistic bioaccumulation model, confirmed these positive effects on the body burdens but suggested lower effects of migration, opportunistic feeding, and TL (1.55, 2.39, and 2.38) than did our statistical analysis. These two independent approaches demonstrate that the effects of migration and opportunistic feeding on seabird body burdens can be similar to that of an increase of one TL and should therefore be accounted for in future analyses.

Serum PCB profiles in Native Americans from Wisconsin based on region, diet, age, and gender: Implications for epidemiology studies

International Nuclear Information System (INIS)

Schaeffer, David J.; Dellinger, John A.; Needham, Larry L.; Hansen, Larry G.

2006-01-01

Background: Different PCB congeners and different mixtures of congeners have been demonstrated to have different biological actions. More complete characterization of congener profiles in exposure sources may assist in predicting health outcomes. Methods: Thirty-six (36) polychlorinated biphenyl (PCB) congeners were measured by gas chromatography isotope-dilution mass spectrometry (IDMS) in 314 serum samples from Native Americans in Wisconsin, Michigan and Minnesota. Five dietary groups were established based on the quantity and species of fish consumed and the waters from which the fish were caught. Multivariate statistical methods were able to resolve gender and dietary differences in PCB homologue and PCB congener patterns. Results: Females had higher proportions of lower chlorinated homologues, including a consistently higher proportion of pentaCB 118. The relative presence of the very labile and volatile PCB 18, above 1% of the total PCB in females from the minimal fish consumption and 'other' groups, suggests possible exposure to PCBs in the atmosphere. The dietary group consuming predatory fishes from Lakes Michigan and Superior had the highest serum concentrations of total PCB (mean of 3.1 ng/ml) and the most distinct congener profile. The two dietary groups least dependent on fishing or fishing mostly from inland lakes (non-Great Lakes) had the lowest total PCB concentrations, both with means of 1.4 ng/ml. Conclusions: These serum PCB concentrations were less than those found in earlier studies of fish consumers in the Great Lakes region and may reflect the decrease in PCBs in these lakes

1993 Annual PCB Document for Los Alamos National Laboratory EPA Region VI, January 1, 1993 through December 31, 1993

International Nuclear Information System (INIS)

Wechsler, R.J.; Sandoval, T.M.; Bryant, D.E.; Hupke, L.; Esquibel, L.

1995-01-01

This document, the open-quotes 1993 Annual PCB Document for Los Alamos National Laboratoryclose quotes was prepared to fulffill the requirements of the federal PCB (Polychlorinated Biphenyl) regulation: 40 CFR 761 Subpart J General Records and Reports. The PCB Management Program at Los Alamos National Laboratory (LANL), Environmental Protection Group, compiled this 1993 Annual PCB Document. The overall format generally follows the sequence of the applicable regulations. Subsection 1.2 cross references those regulatory requirements with the applicable Document Section. The scope of this document also includes status summaries of various aspects of LANL's PCB Management Program. The intent of this approach to the Annual Document is to provide an overview of LANL's PCB Management Program and to increase the usefulness of this document as a management tool. Section 2.0, open-quotes Status of the PCB Management Programclose quotes, discusses the use, generation of waste, and storage of PCBs at LANL. Section 3.0 is the 1993 Annual Document Log required by 761.180(a). This Section also discusses the PCB Management Program's policies for reporting under those regulatory requirements. Sections 4.0 and 5.0 contain the 1993 Annual Records for off-site and on-site disposal as required by 761.180(b). There is a tab for each manifest and its associated continuation sheets, receipt letters, and certificates of disposal

MicroRNA-126 induces autophagy by altering cell metabolism in malignant mesothelioma

Czech Academy of Sciences Publication Activity Database

Tomasetti, M.; Monaco, F.; Manzella, N.; Rohlena, Jakub; Rohlenová, Kateřina; Staffolani, S.; Gaetani, S.; Ciarapica, V.; Amati, M.; Bracci, M.; Valentino, M.; Goodwin, J.; Nguyen, M.; Truksa, Jaroslav; Sobol, Margaryta; Hozák, Pavel; Dong, L.F.; Santarelli, L.; Neužil, Jiří

2016-01-01

Roč. 7, č. 24 (2016), s. 36338-36352 ISSN 1949-2553 R&D Projects: GA ČR(CZ) GAP301/10/1937; GA MŠk LM2015062; GA TA ČR(CZ) TE01020118; GA ČR(CZ) GA16-22823S; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 ; RVO:68378050 Keywords : pyruvate-dehydrogenase kinase * mir-126 * angiogenesis * tumor suppression Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.168, year: 2016

Application of a Bimetallic Treatment System (BTS) for PCB Removal from Older Structures on DoD Facilities

Science.gov (United States)

2010-11-05

Umbilical Tower at KSC. Additionally, main engine test stands at Marshall Space Flight Center (MSFC) were tested for PCB removal and destruction using...test stands at Marshall Space Flight Center (MSFC) were tested for PCB removal and destruction using BTS. The original BTS formulation developed...as on an island , or in the arctic. All the scenarios evaluated in the costs model have assumed the treatment of PCB -containing materials down to

Hepatic Metabolism Affects the Atropselective Disposition of 2,2′,3,3′,6,6′-Hexachlorobiphenyl (PCB 136) in Mice

Science.gov (United States)

2015-01-01

To understand the role of hepatic vs extrahepatic metabolism in the disposition of chiral PCBs, we studied the disposition of 2,2′,3,3′,6,6′-hexachlorobiphenyl (PCB 136) and its hydroxylated metabolites (HO-PCBs) in mice with defective hepatic metabolism due to the liver-specific deletion of cytochrome P450 oxidoreductase (KO mice). Female KO and congenic wild type (WT) mice were treated with racemic PCB 136, and levels and chiral signatures of PCB 136 and HO-PCBs were determined in tissues and excreta 3 days after PCB administration. PCB 136 tissue levels were higher in KO compared to WT mice. Feces was a major route of PCB metabolite excretion, with 2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol being the major metabolite recovered from feces. (+)-PCB 136, the second eluting PCB 136 atropisomers, was enriched in all tissues and excreta. The second eluting atropisomers of the HO-PCBs metabolites were enriched in blood and liver; 2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol in blood was an exception and displayed an enrichment of the first eluting atropisomers. Fecal HO-PCB levels and chiral signatures changed with time and differed between KO and WT mice, with larger HO-PCB enantiomeric fractions in WT compared to KO mice. Our results demonstrate that hepatic and, possibly, extrahepatic cytochrome P450 (P450) enzymes play a role in the disposition of PCBs. PMID:25420130

Dioxin, furan and PCB serum levels in a South African Tswana population: comparing the polluting effects of using different cooking and heating fuels.

Science.gov (United States)

Pieters, Rialet; Focant, Jean-François

2014-05-01

In South Africa, 26-50% of households use solid fuel for cooking food and heating houses. When used as fuel, wood and chlorinated waste are known sources of polychlorinated dibenzo-para-dioxins, polychlorinated dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs). Here, we compare PCDD/F, dioxin-like PCB (DL-PCB), and non-DL-PCB (NDL-PCB) levels in serum of 693 Tswana individuals in the North West province, who either burn solid biofuels or have access to electricity, gas, and paraffin. This is the first South African study on dioxin levels in humans with more than 100 participants. Serum was pooled according to fuel use, as well as to confounding factors such as gender and age. Solid-phase extraction was used to remove the target analytes from serum, after which the extracts were further refined automatically using a combination of multilayer sorbents. Compound concentrations were determined by high-resolution mass spectrometry after high-resolution gas chromatography. Mean serum lipid content was determined enzymatically to be 5.91 ± 0.42 g/L. The PCDD/F and DL-PCB levels were similar to global concentrations reported for non-exposed adults. The mean of the total Toxic Equivalencies (ΣTEQ) was 6.9 ± 3.3 pg/g lipid and the mean NDL-PCB was 70.1 ± 42.8 ng/g lipid. The mean concentrations of the PCDDs, PCDFs and the corresponding World Health Organization-TEQ (WHO-TEQ) of the population using electricity, gas, and paraffin were greater than of those reliant on solid biomass (p = 0), whereas the DL-PCBs, their corresponding WHO-TEQ, and NDL-PCBs were greater for the population who use biofuels but not significantly so. The females had higher serum levels of the PCDDs (p = 0) and PCDFs (not significant) whereas the PCBs were higher for the males (p = 0). Breastfeeding women presented lower levels of all compound classes than their non-breastfeeding counterparts (p=0) and older subjects manifested greater pollutant loads than the younger generation (p = 0

Aquatic contaminants alter genes involved in neurotransmitter synthesis and gonadotropin release in largemouth bass

Energy Technology Data Exchange (ETDEWEB)

Martyniuk, Christopher J. [Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Sanchez, Brian C. [Department of Forestry and Natural Resources and School of Civil Engineering, 195 Marsteller St., Purdue University, West Lafayette, IN 47907 (United States); Szabo, Nancy J.; Denslow, Nancy D. [Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Sepulveda, Maria S., E-mail: mssepulv@purdue.edu [Department of Forestry and Natural Resources and School of Civil Engineering, 195 Marsteller St., Purdue University, West Lafayette, IN 47907 (United States)

2009-10-19

Many aquatic contaminants potentially affect the central nervous system, however the underlying mechanisms of how toxicants alter normal brain function are not well understood. The objectives of this study were to compare the effects of emerging and prevalent environmental contaminants on the expression of brain transcripts with a role in neurotransmitter synthesis and reproduction. Adult male largemouth bass (Micropterus salmoides) were injected once for a 96 h duration with control (water or oil) or with one of two doses of a single chemical to achieve the following body burdens ({mu}g/g): atrazine (0.3 and 3.0), toxaphene (10 and 100), cadmium (CdCl{sub 2}) (0.000067 and 0.00067), polychlorinated biphenyl (PCB) 126 (0.25 and 2.5), and phenanthrene (5 and 50). Partial largemouth bass gene segments were cloned for enzymes involved in neurotransmitter (glutamic acid decarboxylase 65, GAD65; tyrosine hydroxylase) and estrogen (brain aromatase; CYP19b) synthesis for real-time PCR assays. In addition, neuropeptides regulating feeding (neuropeptide Y) and reproduction (chicken GnRH-II, cGnRH-II; salmon GnRH, sGnRH) were also investigated. Of the chemicals tested, only cadmium, PCB 126, and phenanthrene showed any significant effects on the genes tested, while atrazine and toxaphene did not. Cadmium (0.000067 {mu}g/g) significantly increased cGnRH-II mRNA while PCB 126 (0.25 {mu}g/g) decreased GAD65 mRNA. Phenanthrene decreased GAD65 and tyrosine hydroxylase mRNA levels at the highest dose (50 {mu}g/g) but increased cGnRH-II mRNA at the lowest dose (5 {mu}g/g). CYP19b, NPY, and sGnRH mRNA levels were unaffected by any of the treatments. A hierarchical clustering dendrogram grouped PCB 126 and phenanthrene more closely than other chemicals with respect to the genes tested. This study demonstrates that brain transcripts important for neurotransmitter synthesis neuroendocrine function are potential targets for emerging and prevalent aquatic contaminants.

Aquatic contaminants alter genes involved in neurotransmitter synthesis and gonadotropin release in largemouth bass

International Nuclear Information System (INIS)

Martyniuk, Christopher J.; Sanchez, Brian C.; Szabo, Nancy J.; Denslow, Nancy D.; Sepulveda, Maria S.

2009-01-01

Many aquatic contaminants potentially affect the central nervous system, however the underlying mechanisms of how toxicants alter normal brain function are not well understood. The objectives of this study were to compare the effects of emerging and prevalent environmental contaminants on the expression of brain transcripts with a role in neurotransmitter synthesis and reproduction. Adult male largemouth bass (Micropterus salmoides) were injected once for a 96 h duration with control (water or oil) or with one of two doses of a single chemical to achieve the following body burdens (μg/g): atrazine (0.3 and 3.0), toxaphene (10 and 100), cadmium (CdCl 2 ) (0.000067 and 0.00067), polychlorinated biphenyl (PCB) 126 (0.25 and 2.5), and phenanthrene (5 and 50). Partial largemouth bass gene segments were cloned for enzymes involved in neurotransmitter (glutamic acid decarboxylase 65, GAD65; tyrosine hydroxylase) and estrogen (brain aromatase; CYP19b) synthesis for real-time PCR assays. In addition, neuropeptides regulating feeding (neuropeptide Y) and reproduction (chicken GnRH-II, cGnRH-II; salmon GnRH, sGnRH) were also investigated. Of the chemicals tested, only cadmium, PCB 126, and phenanthrene showed any significant effects on the genes tested, while atrazine and toxaphene did not. Cadmium (0.000067 μg/g) significantly increased cGnRH-II mRNA while PCB 126 (0.25 μg/g) decreased GAD65 mRNA. Phenanthrene decreased GAD65 and tyrosine hydroxylase mRNA levels at the highest dose (50 μg/g) but increased cGnRH-II mRNA at the lowest dose (5 μg/g). CYP19b, NPY, and sGnRH mRNA levels were unaffected by any of the treatments. A hierarchical clustering dendrogram grouped PCB 126 and phenanthrene more closely than other chemicals with respect to the genes tested. This study demonstrates that brain transcripts important for neurotransmitter synthesis neuroendocrine function are potential targets for emerging and prevalent aquatic contaminants.

Aquatic contaminants alter genes involved in neurotransmitter synthesis and gonadotropin release in largemouth bass.

Science.gov (United States)

Martyniuk, Christopher J; Sanchez, Brian C; Szabo, Nancy J; Denslow, Nancy D; Sepúlveda, Maria S

2009-10-19

Many aquatic contaminants potentially affect the central nervous system, however the underlying mechanisms of how toxicants alter normal brain function are not well understood. The objectives of this study were to compare the effects of emerging and prevalent environmental contaminants on the expression of brain transcripts with a role in neurotransmitter synthesis and reproduction. Adult male largemouth bass (Micropterus salmoides) were injected once for a 96 h duration with control (water or oil) or with one of two doses of a single chemical to achieve the following body burdens (microg/g): atrazine (0.3 and 3.0), toxaphene (10 and 100), cadmium (CdCl(2)) (0.000067 and 0.00067), polychlorinated biphenyl (PCB) 126 (0.25 and 2.5), and phenanthrene (5 and 50). Partial largemouth bass gene segments were cloned for enzymes involved in neurotransmitter (glutamic acid decarboxylase 65, GAD65; tyrosine hydroxylase) and estrogen (brain aromatase; CYP19b) synthesis for real-time PCR assays. In addition, neuropeptides regulating feeding (neuropeptide Y) and reproduction (chicken GnRH-II, cGnRH-II; salmon GnRH, sGnRH) were also investigated. Of the chemicals tested, only cadmium, PCB 126, and phenanthrene showed any significant effects on the genes tested, while atrazine and toxaphene did not. Cadmium (0.000067 microg/g) significantly increased cGnRH-II mRNA while PCB 126 (0.25 microg/g) decreased GAD65 mRNA. Phenanthrene decreased GAD65 and tyrosine hydroxylase mRNA levels at the highest dose (50 microg/g) but increased cGnRH-II mRNA at the lowest dose (5 microg/g). CYP19b, NPY, and sGnRH mRNA levels were unaffected by any of the treatments. A hierarchical clustering dendrogram grouped PCB 126 and phenanthrene more closely than other chemicals with respect to the genes tested. This study demonstrates that brain transcripts important for neurotransmitter synthesis neuroendocrine function are potential targets for emerging and prevalent aquatic contaminants.

PCB exposure in sea otters and harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill

Science.gov (United States)

Ricca, Mark A.; Miles, A. Keith; Ballachey, Brenda E.; Bodkin, James L.; Esler, Daniel N.; Trust, Kimberly A.

2010-01-01

Exposure to contaminants other than petroleum hydrocarbons could confound interpretation of Exxon Valdez oil spill effects on biota at Prince William Sound, Alaska. Hence, we investigated polychlorinated biphenyls (PCBs) in blood of sea otters and harlequin ducks sampled during 1998. PCB concentrations characterized by lower chlorinated congeners were highest in sea otters from the unoiled area, whereas concentrations were similar among harlequin ducks from the oiled and unoiled area. Blood enzymes often elevated by xenobiotics were not related to PCB concentrations in sea otters. Only sea otters from the unoiled area had estimated risk from PCBs, and PCB composition or concentrations did not correspond to reported lower measures of population performance in sea otters or harlequin ducks from the oiled area. PCBs probably did not influence limited sea otter or harlequin duck recovery in the oiled area a decade after the spill.

Polychlorinated biphenyls and organochlorine pesticides in various bird species from northern China

Energy Technology Data Exchange (ETDEWEB)

Chen Da [Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, 1208 Greate Road, Gloucester Point, VA 23062 (United States); Zhang Xiulan; Mai Bixian [State Key Laboratory of Organic Chemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Sun Quanhui [Beijing Raptor Rescue Center, International Fund for Animal Welfare, Beijing 100875 (China); Song Jie [Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875 (China); Luo Xiaojun; Zeng, Eddy Y. [State Key Laboratory of Organic Chemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Hale, Robert C., E-mail: hale@vims.ed [Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, 1208 Greate Road, Gloucester Point, VA 23062 (United States)

2009-07-15

Little data are available on organochlorine contamination in Chinese terrestrial birds of prey. This study examined the presence of PCBs, DDTs and other organochlorine pesticides in various raptors from northern China. DDE exhibited the highest concentrations among targeted compounds. Greatest levels (23.5-1020 mg/kg lipid weight) were observed in Eurasian sparrowhawks. This may be due to their stopover in southeastern China, where high DDT and dicofol applications have been documented. Residential kestrels exhibited much lower DDE, but similar PCB and HCH concentrations. SIGMATEQs and PCB-126/-77 concentration ratios exhibited significant positive correlations with SIGMAPCB concentrations, respectively. Similar results were also demonstrated by a meta-analysis of previously published data across avian species. Possible hepatic sequestration of coplanar PCB-77, -126, -169 and -118 was observed as liver TEQs increased in Eurasian sparrowhawks. These observations may indicate an induction of CYP1A enzymes, as a result of elevated contamination in some species. - Substantial bioaccumulation of organochlorine contaminants may cause toxic effects (i.e., an induction of Cytochrome P450 enzymes) in birds of prey from the northern China.

Human exposure to PCBs and some other presistent organochlorines in eastern Slovakia as a consequence of former PCB production

Energy Technology Data Exchange (ETDEWEB)

Kocan, A.; Drobna, B.; Petrik, J.; Jursa, S.; Chovancova, J.; Conka, K.; Balla, B.; Sovcikova, E.; Trnovec, T. [Slovak Medical Univ., Bratislava (Czechoslovakia)

2004-09-15

Out of estimated 1.3 million tonnes of PCBs totally produced in the world, about 21,500 t were manufactured in 1959-1984 by the chemical plant Chemko situated at the town of Strazske, Michalovce District, eastern Slovakia. Chemko PCB products called Delor 103, Delor 105, Delor 106, Delotherm and Hydelor were used inside former Czechoslovakia chiefly as heat transfer fluids, capacitor and transformer oils, and paint additives. Because of poor production technology, especially in the 1960s and early 1970s, high amounts of PCB waste discharged, into an open, several km long, muddy Chemko effluent canal causing the increased contamination of the nearby Laborec River and Zemplinska Sirava Lake. A higher PCB content in water sediment, surface water, soil, and air has resulted in high exposure of wild fish and food products coming from cattle, swine and poultry kept in the polluted area and fed with locally produced feed. Two previous pilot studies realized in 1993 and 1997-98 indicated that mean PCB levels measured in the blood, adipose tissue and milk of the human population living in the polluted area (Michalovce District) are several times higher if compared with other Slovak districts. The objective of this exposure oriented part of the EU's 5{sup th} Framework Programme PCBRISK project (www.pcbrisk.sk) was to evaluate the PCB and selected organochlorine pesticide exposure of minimally 2,000 adults (equally men and women) and 400 children (equally boys and girls, 8/9 years old) living in the towns and villages of the Michalovce District adjacent to the Laborec River downstream the Chemko plant where higher PCB human levels could be expected and in the towns and villages of the Svidnik and Stropkov Districts lying several tens km upstream the Laborec where lower PCB exposure was expected. The exposure of at least 300 adults out of those 2,000 to dioxins, furans and dioxin-like PCBs was evaluated as well. The assessment of health effects and other factors

21 CFR 509.30 - Temporary tolerances for polychlorinated biphenyls (PCB's).

Science.gov (United States)

2010-04-01

...) are toxic, industrial chemicals. Because of their widespread, uncontrolled industrial applications... residues of PCB's as unavoidable environmental or industrial contaminants are established for a sufficient...

Liver proteome response of largemouth bass (Micropterus salmoides) exposed to several environmental contaminants: Potential insights into biomarker development

International Nuclear Information System (INIS)

Sanchez, Brian C.; Ralston-Hooper, Kimberly J.; Kowalski, Kevin A.; Dorota Inerowicz, H.; Adamec, Jiri; Sepulveda, Maria S.

2009-01-01

Liver proteome response of largemouth bass (Micropterus salmoides) exposed to environmental contaminants was analyzed to identify novel biomarkers of exposure. Adult male bass were exposed to cadmium chloride (CdCl 2 ), atrazine, PCB 126, phenanthrene, or toxaphene via intraperitoneal injection with target body burdens of 0.00067, 3.0, 2.5, 50, and 100 μg/g, respectively. After a 96 h exposure, hepatic proteins were separated with two-dimensional gel electrophoresis and differentially expressed proteins (vs. controls) recognized and identified with MALDI-TOF/TOF mass spectrometry. We identified, 30, 18, eight, 19, and five proteins as differentially expressed within the CdCl 2 , atrazine, PCB 126, phenanthrene, and toxaphene treatments, respectively. Alterations were observed in the expression of proteins associated with cellular ion homeostasis (toxaphene), oxidative stress (phenanthrene, PCB 126), and energy production including glycolysis (CdCl 2 , atrazine) and ATP synthesis (atrazine). This work supports the further evaluation of several of these proteins as biomarkers of contaminant exposure in fish.

The Role of Circulating MicroRNA-126 (miR-126: A Novel Biomarker for Screening Prediabetes and Newly Diagnosed Type 2 Diabetes Mellitus

Directory of Open Access Journals (Sweden)

Yang Liu

2014-06-01

Full Text Available Recent studies suggested an association of endothelial microRNA-126 (miR-126 with type 2 diabetes mellitus (T2DM. In the current study, we examined whether circulating miR-126 is associated with T2DM and pre-diabetic syndrome. The study included 82 subjects with impaired glucose tolerance (IGT, 75 subjects with impaired fasting glucose (IFG, 160 patients with newly diagnosed T2DM, and 138 healthy individuals. Quantitative polymerase chain reaction (qPCR was used to examine serum miR-126. Serum miR-126 was significantly lower in IGT/IFG subjects and T2DM patients than in healthy controls (p < 0.05. After six months of treatment (diet control and exercise in IGT/IFG subjects, insulin plus diet control and exercise in T2DM patients, serum miR-126 increased significantly (p < 0.05. An analysis based on serum miR-126 in the sample revealed a significantly higher odds ratio (OR for the subjects with the lowest 1/3 of serum miR-126 for T2DM (OR: 3.500, 95% confidence interval: 1.901–6.445, p < 0.05 than subjects within the highest 1/3 of serum miR-126. Such an association was still apparent after adjusting for other major risk factors. The area under the curve (AUC for the receiver-operating characteristic (ROC analysis was 0.792 (95% confidence interval: 0.707–0.877, p < 0.001. These results encourage the use of serum miR-126 as a biomarker for pre-diabetes and diabetes mellitus, as well as therapeutic response.

Enrichment and Characterization of PCB-Degrading Bacteria as Potential Seed Cultures for Bioremediation of Contaminated Soil

Directory of Open Access Journals (Sweden)

Dubravka Hršak

2007-01-01

Full Text Available The main objective of our study was to obtain seed cultures for enhancing the transformation of polychlorinated biphenyls (PCBs in contaminated soil of the transformer station in Zadar, Croatia, damaged during warfare activities in 1991. For enrichment, six soil samples were collected from different polluted areas and microcosm approach, stimulating the growth of biphenyl-degrading bacteria, was employed. Enrichment experiments resulted in the selection of two fast growing mixed cultures TSZ7 and AIR1, originating from the soil of the transformer station and the airport area, respectively. Both cultures showed significant PCB-degrading activity (56 to 60 % of PCB50 mixture was reduced after a two-week cultivation. Furthermore, the cultures displayed similar PCB-degrading competence and reduced di-to tetrachlorobiphenyls more effectively than penta- to hepta-chlorobiphenyls. Strain Z6, identified as Rhodococcus erythropolis, was found to be the only culture member showing PCB-transformation potential similar to that of the mixed culture TSZ7, from which it was isolated. Based on the metabolites identified in the assay with the single congener 2,4,4’-chlorobiphenyl, we proposed that the strain Z6 was able to use both the 2,3-and 3,4-dioxygenase pathways. Furthermore, the identified metabolites suggested that beside these pathways another unidentified pathway might also be active in strain Z6. Based on the obtained results, the culture TSZ7 and the strain Z6 were designated as potential seed cultures for bioremediation of the contaminated soil.

The role of circulating microRNA-126 (miR-126): a novel biomarker for screening prediabetes and newly diagnosed type 2 diabetes mellitus.

Science.gov (United States)

Liu, Yang; Gao, Guangqiang; Yang, Chun; Zhou, Kun; Shen, Baozhong; Liang, Hongyan; Jiang, Xiaofeng

2014-06-12

Recent studies suggested an association of endothelial microRNA-126 (miR-126) with type 2 diabetes mellitus (T2DM). In the current study, we examined whether circulating miR-126 is associated with T2DM and pre-diabetic syndrome. The study included 82 subjects with impaired glucose tolerance (IGT), 75 subjects with impaired fasting glucose (IFG), 160 patients with newly diagnosed T2DM, and 138 healthy individuals. Quantitative polymerase chain reaction (qPCR) was used to examine serum miR-126. Serum miR-126 was significantly lower in IGT/IFG subjects and T2DM patients than in healthy controls (pdiet control and exercise in IGT/IFG subjects, insulin plus diet control and exercise in T2DM patients), serum miR-126 increased significantly (pdiabetes and diabetes mellitus, as well as therapeutic response.

Studies on the distribution of 14C labelled PCB in the body, 2

International Nuclear Information System (INIS)

Nagao, Soshichi; Hosoya, Hideo; Kugoh, Tadashi

1975-01-01

Authors carried out the experiments of 14 C-PCB distribution in fish (Carrasius auratus) by autoradiography. 0.1 micro Ci of 14 C-PCB solution was administrated by both methods, one of the method was used as mixture of PCB solution in the environmental water of the fish and other one was used as orally medication for the fish. The fish were kept in 300 ml of exposed with 500 ml beaker per fish, and then the fish were killed for the sake of autoradiography at 1, 3, 6 and 24 hours of the experiments. Radioactivity of the water was analyzed at each experimental time as cpm/ml. In cases of the administration in the environmental water, radioactivity of the water was reducing in direct relation to the period in the contact time between the fish and the water, and autoradiogram appeared that radioactivity of the sectioning body plate was increasing in parallel with the contact in the water with the fish. In cases of the oral medication, radioactivity in the water and autoradiogram were increasing in direct relation to the period in the contact time. In both cases 14 C-PCB was found into the brain and spinal cord, it was special finding as compared with other animals. (auth.)

Preparation and Characterization of Lecithin-Nano Ni/Fe for Effective Removal of PCB77

OpenAIRE

Shu Ding; Lin Zhao; Yun Qi; Qian-qian Lv

2014-01-01

A kind of combined material (named lecithin-nano Ni/Fe) that is composed of lecithin and nanoscale Ni/Fe bimetal was synthesized via microemulsion method. The efficacy of such an original material was tested using 3,3′,4,4′-tetrachlorobiphenyl (PCB77) as target pollutant. A microemulsion system was optimized as template to prepare Ni/Fe nanoparticles, which was followed by an insite loading process with the deposition of lecithin carrier. It was proved by the characterization that subtle Ni/F...

Passive sampling of polychlorinated biphenyls (PCB) in indoor air

DEFF Research Database (Denmark)

Vorkamp, Katrin; Mayer, Philipp

PCBs were widely used in construction materials in the 1906s and 1970s, a period of high building activity in Denmark. The objective of this study was therefore to use passive sampling techniques to develop a simple and cost-effective screening tool for PCBs in indoor air. The study proceeded...... in three phases combining a literature review, laboratory experiments and measurements in buildings potentially containing PCBs in indoor air. The laboratory experiments showed a strong influence of air velocity on the PCB partitioning between air and the passive sampler. Based on the results of the first...

22 CFR 126.9 - Advisory opinions and related authorizations.

Science.gov (United States)

2010-04-01

.... 126.9 Section 126.9 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.9 Advisory opinions and related authorizations. (a) Advisory opinion. Any person desiring information as to whether the Directorate of Defense Trade Controls would be...

Prenatal exposure to PCB-153, p,p'-DDE and birth outcomes in 9000 mother-child pairs

DEFF Research Database (Denmark)

Casas, Maribel; Nieuwenhuijsen, Mark; Martínez, David

2014-01-01

Low-level exposure to polychlorinated biphenyl-153 (PCB-153) and dichlorodiphenyldichloroethylene (p-p'-DDE) can impair fetal growth; however, the exposure-response relationship and effect modifiers of such association are not well established. This study is an extension of an earlier European me...

Downregulation of MicroRNA-126 Contributes to the Failing Right Ventricle in Pulmonary Arterial Hypertension.

Science.gov (United States)

Potus, François; Ruffenach, Grégoire; Dahou, Abdellaziz; Thebault, Christophe; Breuils-Bonnet, Sandra; Tremblay, Ève; Nadeau, Valérie; Paradis, Renée; Graydon, Colin; Wong, Ryan; Johnson, Ian; Paulin, Roxane; Lajoie, Annie C; Perron, Jean; Charbonneau, Eric; Joubert, Philippe; Pibarot, Philippe; Michelakis, Evangelos D; Provencher, Steeve; Bonnet, Sébastien

2015-09-08

Right ventricular (RV) failure is the most important factor of both morbidity and mortality in pulmonary arterial hypertension (PAH). However, the underlying mechanisms resulting in the failed RV in PAH remain unknown. There is growing evidence that angiogenesis and microRNAs are involved in PAH-associated RV failure. We hypothesized that microRNA-126 (miR-126) downregulation decreases microvessel density and promotes the transition from a compensated to a decompensated RV in PAH. We studied RV free wall tissues from humans with normal RV (n=17), those with compensated RV hypertrophy (n=8), and patients with PAH with decompensated RV failure (n=14). Compared with RV tissues from patients with compensated RV hypertrophy, patients with decompensated RV failure had decreased miR-126 expression (quantitative reverse transcription-polymerase chain reaction; P<0.01) and capillary density (CD31(+) immunofluorescence; P<0.001), whereas left ventricular tissues were not affected. miR-126 downregulation was associated with increased Sprouty-related EVH1 domain-containing protein 1 (SPRED-1), leading to decreased activation of RAF (phosphorylated RAF/RAF) and mitogen-activated protein kinase (MAPK); (phosphorylated MAPK/MAPK), thus inhibiting the vascular endothelial growth factor pathway. In vitro, Matrigel assay showed that miR-126 upregulation increased angiogenesis of primary cultured endothelial cells from patients with decompensated RV failure. Furthermore, in vivo miR-126 upregulation (mimic intravenous injection) improved cardiac vascular density and function of monocrotaline-induced PAH animals. RV failure in PAH is associated with a specific molecular signature within the RV, contributing to a decrease in RV vascular density and promoting the progression to RV failure. More importantly, miR-126 upregulation in the RV improves microvessel density and RV function in experimental PAH. © 2015 American Heart Association, Inc.

Assessing PCB pollution in the Baltic Sea - An equilibrium partitioning based study

DEFF Research Database (Denmark)

Lang, Susann-Cathrin; Mayer, Philipp; Hursthouse, Andrew

2018-01-01

Sediment cores and bottom water samples from across the Baltic Sea region were analyzed for freely dissolved concentrations (Cfree), total sediment concentrations (CT) and the dissolved aqueous fraction in water of seven indicator PCBs. Ex-situ equilibrium sampling of sediment samples was conducted...... with polydimethylsiloxane (PDMS) coated glass fibers that were analyzed by automated thermal desorption GC-MS, which yielded PCB concentrations in the fiber coating (CPDMS). Measurements of CPDMS and CT were then applied to determine (i) spatially resolved freely dissolved PCB concentrations; (ii) baseline toxicity...

Cardioprotective Effect of Crocin Combined with Voluntary Exercise in Rat: Role of Mir-126 and Mir-210 in Heart Angiogenesis.

Science.gov (United States)

Ghorbanzadeh, Vajihe; Mohammadi, Mustafa; Dariushnejad, Hassan; Abhari, Alireza; Chodari, Leila; Mohaddes, Gisou

2017-07-01

Crocin is reported to have a wide range of biological activities such as cardiovascular protection. Recent epidemiologic studies have shown that exercise reduces cardiovascular morbidity and mortality in the general population. The aim of this study was to evaluate the effect of crocin and voluntary exercise on miR-126 and miR-210 expression levels and angiogenesis in the heart tissue. Animals were divided into 4 groups: control, exercise, crocin, and exercise-crocin. Animals received oral administration of crocin (50 mg/kg) or performed voluntary exercise alone or together for 8 weeks. Akt, ERK1/2 protein levels, miR-126 and miR-210 expression were measured in the heart tissue. Immunohistochemical method was used to detect CD31 in the heart tissue. Akt and ERK1/2 levels of the heart tissue were higher in crocin treated group and voluntary exercise trained group after 8 weeks. Combination of crocin and exercise also significantly enhanced Akt and ERK1/2 levels in the heart tissue. MiR-126, miR-210 expression and CD31 in the heart increased in both crocin and voluntary exercise groups compared with control group. In addition, combination of exercise and crocin amplified their effect on miR-126 and miR-210 expression, and angiogenesis. Crocin and voluntary exercise improve heart angiogenesis possibly through enhancement of miR-126 and miR-210 expression. Voluntary exercise and diet supplementation with crocin could have beneficial effects in prevention of cardiovascular disease. A crocina tem uma vasta gama de atividades biológicas, tais como a proteção cardiovascular. Estudos epidemiológicos recentes demonstraram que o exercício reduz a morbidade e a mortalidade cardiovasculares na população em geral. O objetivo deste estudo foi avaliar o efeito da crocina e do exercício voluntário nos níveis de expressão miR-126 e miR-210 e na angiogênese no tecido cardíaco. Os animais foram divididos em 4 grupos: controle, exercício, crocina e exercício-crocina. Os

Combined use of different Gfp reporters for monitoring single-cell activities of a genetically modified PCB degrader in the rhizosphere of alfalfa

DEFF Research Database (Denmark)

Boldt, T.S.; Sørensen, J.; Karlsson, U.

2004-01-01

Single-cell localization and activity of Pseudomonas,fluorescens F113, colonizing alfalfa roots, were monitored using fusions of the Escherichia coli rrnBP1 ribosomal promoter and gfp genes encoding green fluorescent protein (Gfp) of different stability. The monitoring systems permitted non...... of chlorinated biphenyl was constructed, using another gfp fusion with the meta-pathway Pin promoter from Pseudomonas putida (TOL plasmid). Expression of this promoter, which is strongly induced by the PCB-2 degradation product, 3-chlorobenzoate, was tested in vitro and subsequently monitored in vivo on alfalfa...... roots using the P. fluorescens F113rifpcb reporter. A small but distinct fraction of the introduced bacteria activated the Pm promoter and thus appeared to sense a PCB-2 degradation product in the alfalfa rhizosphere. The degrading cells, which by design were identical to the sensing cells, were located...

Polychlorinated biphenyls (PCB's) levels in transformer oils from selected transformers in sensitive areas in the Greater Accra Region

International Nuclear Information System (INIS)

Buah-Kwofie, A.

2009-02-01

Knowledge of PCBs and the adverse effects on humans and the environment have been assessed among Electricity Company of Ghana (ECG) staff members, Volta River Authority (VRA) staff members and the general public. Evidence obtained shows that, Staff members of the technical departments of ECG/VRA (71.4 %) as well as a few welders (16.7 %) have come in contact with the transformer oil that may possibly contain PCBs. About fifty six percent (55.6 %) of the ECG/VRA staff members do not wear any protective gears when working on these transformers thus exposing themselves to PCBs. About twenty seven percent (27.3 %) of the management staff members of ECG/VRA are not aware of the adverse health effects caused by PCBs. Using PCB test kits (CLOR-N-OIL) developed by Dexsil Company of USA, 17 out of the 80 transformers screened for PCB contaminated oils, tested positive as containing PCBs levels greater than 50 ppm. Neutron Activation Analysis and gamma ray spectroscopy using Canberra HPGe detector coupled to MAESTRO 32 software has been used to determine the total chlorine content in 22 of the transformer oil samples screened using the test kits, including the 17 samples that tested positive using the test kits. The total chlorine content measured in the transformer oils that tested positive by the test kit was in the range of 71.34 ± 8.63 with 6 - 7.5 % accuracy. This being deduced that using NAA, total chlorine greater than 71.34 ppm is an indication of PCB contamination. NAA thus provides a faster and efficient way of analyzing transformer oil samples for possible PCB contamination

A luciferase reporter gene assay and aryl hydrocarbon receptor 1 genotype predict the LD50 of polychlorinated biphenyls in avian species

International Nuclear Information System (INIS)

Manning, Gillian E.; Farmahin, Reza; Crump, Doug; Jones, Stephanie P.; Klein, Jeff; Konstantinov, Alex; Potter, Dave; Kennedy, Sean W.

2012-01-01

Birds differ in sensitivity to the embryotoxic effects of polychlorinated biphenyls (PCBs), which complicates environmental risk assessments for these chemicals. Recent research has shown that the identities of amino acid residues 324 and 380 in the avian aryl hydrocarbon receptor 1 (AHR1) ligand binding domain (LBD) are primarily responsible for differences in avian species sensitivity to selected dibenzo-p-dioxins and furans. A luciferase reporter gene (LRG) assay was developed in our laboratory to measure AHR1-mediated induction of a cytochrome P450 1A5 reporter gene in COS-7 cells transfected with different avian AHR1 constructs. In the present study, the LRG assay was used to measure the concentration-dependent effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and PCBs 126, 77, 105 and 118 on luciferase activity in COS-7 cells transfected with AHR1 constructs representative of 86 avian species in order to predict their sensitivity to PCB-induced embryolethality and the relative potency of PCBs in these species. The results of the LRG assay indicate that the identity of amino acid residues 324 and 380 in the AHR1 LBD are the major determinants of avian species sensitivity to PCBs. The relative potency of PCBs did not differ greatly among AHR1 constructs. Luciferase activity was significantly correlated with embryolethality data obtained from the literature (R 2 ≥ 0.87, p < 0.0001). Thus, the LRG assay in combination with the knowledge of a species' AHR1 LBD sequence can be used to predict PCB-induced embryolethality in potentially any avian species of interest without the use of lethal methods on a large number of individuals. -- Highlights: ► PCB embryolethality in birds can be predicted from a species' AHR1 genotype. ► The reporter gene assay is useful for predicting species sensitivity to PCBs. ► The relative potency of PCBs does not appear to differ between AHR1 genotypes. ► Contamination of PCB 105 and PCB 118 did not affect their relative

A luciferase reporter gene assay and aryl hydrocarbon receptor 1 genotype predict the LD{sub 50} of polychlorinated biphenyls in avian species

Energy Technology Data Exchange (ETDEWEB)

Manning, Gillian E., E-mail: gmann017@uottawa.ca [Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5 (Canada); Environment Canada, National Wildlife Research Centre, Ottawa, ON, Canada K1A 0H3 (Canada); Farmahin, Reza, E-mail: mfarm070@uottawa.ca [Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5 (Canada); Environment Canada, National Wildlife Research Centre, Ottawa, ON, Canada K1A 0H3 (Canada); Crump, Doug, E-mail: doug.crump@ec.gc.ca [Environment Canada, National Wildlife Research Centre, Ottawa, ON, Canada K1A 0H3 (Canada); Jones, Stephanie P., E-mail: stephanie.jones@ec.gc.ca [Environment Canada, National Wildlife Research Centre, Ottawa, ON, Canada K1A 0H3 (Canada); Klein, Jeff, E-mail: jeffery@well-labs.com [Wellington Laboratories Inc., Research Division, Guelph, ON, Canada N1G 3M5 (Canada); Konstantinov, Alex, E-mail: alex@well-labs.com [Wellington Laboratories Inc., Research Division, Guelph, ON, Canada N1G 3M5 (Canada); Potter, Dave, E-mail: dpotter@well-labs.com [Wellington Laboratories Inc., Research Division, Guelph, ON, Canada N1G 3M5 (Canada); Kennedy, Sean W., E-mail: sean.kennedy@ec.gc.ca [Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5 (Canada); Environment Canada, National Wildlife Research Centre, Ottawa, ON, Canada K1A 0H3 (Canada)

2012-09-15

Birds differ in sensitivity to the embryotoxic effects of polychlorinated biphenyls (PCBs), which complicates environmental risk assessments for these chemicals. Recent research has shown that the identities of amino acid residues 324 and 380 in the avian aryl hydrocarbon receptor 1 (AHR1) ligand binding domain (LBD) are primarily responsible for differences in avian species sensitivity to selected dibenzo-p-dioxins and furans. A luciferase reporter gene (LRG) assay was developed in our laboratory to measure AHR1-mediated induction of a cytochrome P450 1A5 reporter gene in COS-7 cells transfected with different avian AHR1 constructs. In the present study, the LRG assay was used to measure the concentration-dependent effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and PCBs 126, 77, 105 and 118 on luciferase activity in COS-7 cells transfected with AHR1 constructs representative of 86 avian species in order to predict their sensitivity to PCB-induced embryolethality and the relative potency of PCBs in these species. The results of the LRG assay indicate that the identity of amino acid residues 324 and 380 in the AHR1 LBD are the major determinants of avian species sensitivity to PCBs. The relative potency of PCBs did not differ greatly among AHR1 constructs. Luciferase activity was significantly correlated with embryolethality data obtained from the literature (R{sup 2} ≥ 0.87, p < 0.0001). Thus, the LRG assay in combination with the knowledge of a species' AHR1 LBD sequence can be used to predict PCB-induced embryolethality in potentially any avian species of interest without the use of lethal methods on a large number of individuals. -- Highlights: ► PCB embryolethality in birds can be predicted from a species' AHR1 genotype. ► The reporter gene assay is useful for predicting species sensitivity to PCBs. ► The relative potency of PCBs does not appear to differ between AHR1 genotypes. ► Contamination of PCB 105 and PCB 118 did not affect

7 CFR 959.126 - Handling of culls.

Science.gov (United States)

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Handling of culls. 959.126 Section 959.126 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements...) Handled for canning or freezing. (b) As a safeguard against culls entering fresh market channels each...

Endothelial microparticle-mediated transfer of MicroRNA-126 promotes vascular endothelial cell repair via SPRED1 and is abrogated in glucose-damaged endothelial microparticles.

Science.gov (United States)

Jansen, Felix; Yang, Xiaoyan; Hoelscher, Marion; Cattelan, Arianna; Schmitz, Theresa; Proebsting, Sebastian; Wenzel, Daniela; Vosen, Sarah; Franklin, Bernardo S; Fleischmann, Bernd K; Nickenig, Georg; Werner, Nikos

2013-10-29

Repair of the endothelium after vascular injury is crucial for preserving endothelial integrity and preventing the development of vascular disease. The underlying mechanisms of endothelial cell repair are largely unknown. We sought to investigate whether endothelial microparticles (EMPs), released from apoptotic endothelial cells (ECs), influence EC repair. Systemic treatment of mice with EMPs after electric denudation of the endothelium accelerated reendothelialization in vivo. In vitro experiments revealed that EMP uptake in ECs promotes EC migration and proliferation, both critical steps in endothelial repair. To dissect the underlying mechanisms, Taqman microRNA array was performed, and microRNA (miR)-126 was identified as the predominantly expressed miR in EMPs. The following experiments demonstrated that miR-126 was transported into recipient human coronary artery endothelial cells by EMPs and functionally regulated the target protein sprouty-related, EVH1 domain-containing protein 1 (SPRED1). Knockdown of miR-126 in EMPs abrogated EMP-mediated effects on human coronary artery endothelial cell migration and proliferation in vitro and reendothelialization in vivo. Interestingly, after simulating diabetic conditions, EMPs derived from glucose-treated ECs contained significantly lower amounts of miR-126 and showed reduced endothelial repair capacity in vitro and in vivo. Finally, expression analysis of miR-126 in circulating microparticles from 176 patients with stable coronary artery disease with and without diabetes mellitus revealed a significantly reduced miR-126 expression in circulating microparticles from diabetic patients. Endothelial microparticles promote vascular endothelial repair by delivering functional miR-126 into recipient cells. In pathological hyperglycemic conditions, EMP-mediated miR-126-induced EC repair is altered.

Bioaccumulation of PCBs in the sea urchin Paracentrotus lividus: seawater and food exposures to a 14C-radiolabelled congener (PCB no. 153)

International Nuclear Information System (INIS)

Danis, B.; Cotret, O.; Teyssie, J.L.; Bustamante, P.; Fowler, S.W.; Warnau, M.

2005-01-01

Adult Paracentrotus lividus were exposed to a 14 C-labelled PCB congener (PCB no. 153) using two different exposure modes: (1) the surrounding sea water and (2) the food (viz. the phanerogam Posidonia oceanica and the brown alga Taonia atomaria). Uptake kinetics from water and loss kinetics after single feeding were followed in four body compartments of the sea urchins (body wall, spines, gut and gonads). Results indicate that PCB bioaccumulation in P. lividus varies from one body compartment to another, with the exposure mode and the nature of the food. The echinoids accumulate PCB no. 153 more efficiently when exposed via water than via the food (the transfer efficiency is higher by one order of magnitude). Target body compartments of PCB no. 153 were found to be body wall and spines when individuals were exposed via water, and gut when they were exposed via food. It is concluded that P. lividus is an efficient bioaccumulator of PCB and that it could be considered as an interesting indicator for monitoring PCB contamination in the marine environment. - The sea urchin Paracentrotus lividus is a valuable indicator for PCB contamination

Effects of occupational exposure to polychlorinated biphenyls on urinary metabolites of neurotransmitters: A cross-sectional and longitudinal perspective.

Science.gov (United States)

Putschögl, Franziska Maria; Gaum, Petra Maria; Schettgen, Thomas; Kraus, Thomas; Gube, Monika; Lang, Jessica

2015-07-01

Polychlorinated biphenyls (PCBs) are chemicals which were used for industrial purposes and are known to induce various adverse health effects. They are also known to be neurotoxic and numerous targets within the central nervous system have been identified in previous studies. Specifically, the neurotransmitters dopamine (DA) and norepinephrine (NE) are influenced by PCBs as indicated in studies involving animals. However, limited evidence has been published documenting PCB induced changes in the neurotransmitter system in humans. In the present study, we examined the association between a higher PCB body burden following occupational exposure and possible changes in human neurotransmitter metabolites. Within a medical surveillance programme called HELPcB (Health Effects in High-Level Exposure to PCB) that monitors adverse health effects of occupational PCB exposure, urine samples were obtained (n(T1) = 166; n(T2) = 177 and n(T3) = 141). The urinary concentrations of the metabolites homovanillic acid (HVA; for DA) and vanillylmandelic acid (VMA; for NE) were analyzed. Blood samples were obtained by vena puncture in order to determine the internal exposure to PCBs with human biomonitoring. A cross-sectional analysis indicated a significant negative effect of PCB exposure on HVA and VMA. Longitudinally, an initially higher exposure to higher chlorinated PCBs was followed by constant reduced HVA level over three consecutive years. Exploratory analyses show different long-term effects for different PCBs according to their chlorination degree. A higher exposure with lower chlorinated PCBs leads to an increase of VMA and HVA. Conversely, a higher exposure to all PCBs results in a reduction of HVA. This study, to our knowledge, is the first to document changes in neurotransmitter metabolites after occupational PCB exposure in humans. This finding advances evidence obtained from past research, and identifies one potential pathomechanism in the central dopaminergic system of

Biological remediation of polychlorinated biphenyls (PCB) in the ...

African Journals Online (AJOL)

ajl yemi

2011-12-19

Dec 19, 2011 ... This widespread contamination of air, soil and water by metals, chemicals and metalloids causes environmental concerns, ... basic structure of PCB according to Wiegel and Wu. (2000), is as shown in Figure. 1. ..... inability to understand the interaction between complex chemicals in addition to physical and ...

9 CFR 354.126 - Carcasses held for further examination.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Carcasses held for further examination. 354.126 Section 354.126 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... Inspection § 354.126 Carcasses held for further examination. Each carcass, including all parts thereof, in...

PCB management and the environmental movement

International Nuclear Information System (INIS)

White, D.

1995-01-01

Some key issues of public concern about hazardous waste incinerators and, in general, the management of toxic wastes, have been identified with a view to counter arguments brought forward by environmentalists and to offer reassurance based on scientific evidence. The case in point is the long-term management of London's (Ontario) PCB inventory, extensively studied by Proctor and Redfern Ltd., a consultant group. They recommended thermal destruction of the PCBs as the most effective and permanent solution. Their report was subsequently attacked by Greenpeace, whose main concern was the consultants's recommendation to rely on destruction by incineration and removal efficiency values. Greenpeace also raised doubts about recommended measures against emissions of products of incomplete combustion, the incineration of metal containing waste, and the validity of health risk assessment. Evidence from Proctor and Redfern's own consulting experience, and other published scientific studies were used to show the fallacy of Greenpeace's arguments, claiming that they were based on unscientific, outdated and seemingly selective information, resulting in completely misleading assessment of incineration as an effective means of toxic waste management. 7 refs., 2 tabs., 1 fig

Final report for Tank 100 Sump sludge (KON332) for polychlorinated biphenyl's (PCB)

International Nuclear Information System (INIS)

Fuller, R.K.

1998-01-01

Final Report for Tank 100 Sump Sludge (KON332) for Polychlorinated Biphenyl's (PCB) Sample Receipt Sample KON332 was received from Tank 100-Sump (WESF) on May 18, 1998. The laboratory number issued for this sample is S98BOO0207 as shown on the Request for Sample Analysis (RSA) form (Attachment 4). The sample breakdown diagram (Attachment 3) provides a cross-reference of customer sample identification to the laboratory identification number. Attachment 4 provides copies of the Request for Sample Analysis (RSA) and Chain of Custody (COC) forms. The sample was received in the laboratory in a 125-ml polybottle. Breakdown and subsampling was performed on June 6, 1998. PCB analysis was performed on the wet sludge. A discussion of the results is presented in Attachment 2. The 222-S extraction bench sheets are presented in Attachment 5. The PCB raw data are presented in Attachment 6

Variability of PCB burden in 5 fish and sharks species of the French Mediterranean continental slope.

Science.gov (United States)

Cresson, Pierre; Fabri, Marie Claire; Miralles, Françoise Marco; Dufour, Jean-Louis; Elleboode, Romain; Sevin, Karine; Mahé, Kelig; Bouchoucha, Marc

2016-05-01

Despite being generally located far from contamination sources, deep marine ecosystems are impacted by chemicals like PCB. The PCB contamination in five fish and shark species collected in the continental slope of the Gulf of Lions (NW Mediterranean Sea) was measured, with a special focus on intra- and interspecific variability and on the driving factors. Significant differences occurred between species. Higher values were measured in Scyliorhinus canicula, Galeus melastomus and Helicolenus dactylopterus and lower values in Phycis blennoides and Lepidorhombus boscii. These differences might be explained by specific abilities to accumulate and eliminate contaminant, mostly through cytochrome P450 pathway. Interindividual variation was also high and no correlation was observed between contamination and length, age or trophic level. Despite its major importance, actual bioaccumulation of PCB in deep fish is not as documented as in other marine ecosystems, calling for a better assessment of the factors driving individual bioaccumulation mechanisms and originating high variability in PCB contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

MicroRNA-126 Priming Enhances Functions of Endothelial Progenitor Cells under Physiological and Hypoxic Conditions and Their Therapeutic Efficacy in Cerebral Ischemic Damage

Directory of Open Access Journals (Sweden)

Qunwen Pan

2018-01-01

Full Text Available Endothelial progenitor cells (EPCs have shown the potential for treating ischemic stroke (IS, while microRNA-126 (miR-126 is reported to have beneficial effects on endothelial function and angiogenesis. In this study, we investigated the effects of miR-126 overexpression on EPCs and explore the efficacy of miR-126-primed EPCs (EPCmiR-126 in treating IS. The effects of miR-126 overexpression on EPC proliferation, migratory, tube formation capacity, reactive oxygen species (ROS production, and nitric oxide (NO generation were determined. In in vivo study, the effects of EPCmiR-126 on the cerebral blood flow (CBF, neurological deficit score (NDS, infarct volume, cerebral microvascular density (cMVD, and angiogenesis were determined. Moreover, the levels of circulating EPCs (cEPCs and their contained miR-126 were measured. We found (1 miR-126 overexpression promoted the proliferation, migration, and tube formation abilities of EPCs; decreased ROS; and increased NO production of EPCs via activation of PI3K/Akt/eNOS pathway; (2 EPCmiR-126 was more effective than EPCs in attenuating infarct volume and NDS and enhancing cMVD, CBF, and angiogenesis; and (3 infusion of EPCmiR-126 increased the number and the level of miR-126 in cEPCs. Our data indicate that miR-126 overexpression enhanced the function of EPCs in vitro and in vivo.

Levels and trends of PCB 28, PCB 153 and DDE in breast milk from primiparae women in Uppsala County, Sweden

Energy Technology Data Exchange (ETDEWEB)

Darnerud, P.O.; Lignell, S.; Atuma, S.; Aune, M.; Glynn, A. [National Food Administration, Uppsala (Sweden); Cnattingius, S. [Dept. of Epidemiology, Karolinska Inst., Stockholm (Sweden)

2004-09-15

Since 1996, the Swedish NFA has made recurrent measurements of levels of selected POPs, chiefly PCBs, dioxins and persistent pesticides (e.g. DDTs), in human breast milk. The analyses were made on individual basis, which offer possibility to adjust the time trends in POP levels for differences among the participating women in life-style or other factors that could affect the levels in breast milk. The ambition with the NFA sampling is to follow changes in the levels of these environmental contaminants in human breast milk and to continue the Swedish time trend measurements that was started in the 1970s. The measured levels will be used as base for evaluation of possible health risks for the mother and in particular for the breastfed infant. This report presents breast milk results from 1996 to 2003, concentrating on the selected PCB congeners (PCB 28 and 153) and p,p'-DDE. The reason for selecting these compounds are the data showing differences in e.g. sources and persistence, which could make them interesting type substances for larger groups of compounds.

29 CFR 794.126 - Computations for a new business.

Science.gov (United States)

2010-07-01

... million test of the exemption. In other cases, where doubt exists, the gross receipts of the new business... 29 Labor 3 2010-07-01 2010-07-01 false Computations for a new business. 794.126 Section 794.126... of Sales § 794.126 Computations for a new business. When a new business is commenced the employer...

Inhibition of Listeria monocytogenes by piscicolin 126 in milk and Camembert cheese manufactured with a thermophilic starter.

Science.gov (United States)

Wan, J; Harmark, K; Davidson, B E; Hillier, A J; Gordon, J B; Wilcock, A; Hickey, M W; Coventry, M J

1997-03-01

The effect of bacteriocin, piscicolin 126, on the growth of Listeria monocytogenes and cheese starter bacteria was investigated in milk and in Camembert cheese manufactured from milk challenged with 10(2) cfu ml(-1) L. monocytogenes. In milk incubated at 30 degrees C, piscicolin 126 added in the range of 512-2,048 AU ml(-1) effectively inhibited growth of L. monocytogenes for more than 20 d when challenged with approximately 10(2) cfu ml(-1) L. monocytogenes. At higher challenge levels (10(4) and 10(6) cfu ml(-1)), piscicolin 126 reduced the viable count of L. monocytogenes by 4-5 log units immediately after addition of the bacteriocin; however, growth of Listeria occurred within 24 h. The minimum inhibitory concentration (MIC) of piscicolin 126 against lactic acid cheese starter bacteria was generally greater than 204,800 AU ml(-1) , and the viable count and acid production of these starter cultures in milk were not affected by the addition of 2,048 AU ml(-1) piscicolin 126. Camembert cheeses made from milk challenged with L. monocytogenes and with added piscicolin 126 showed a viable count of L. monocytogenes 3-4 log units lower than those without piscicolin 126. Inactivation of piscicolin 126 by proteolytic enzymes from cheese starter bacteria and mould together with the emergence of piscicolin 126-resistant isolates was responsible for the recovery of L. monocytogenes in the cheeses during ripening.

Estimation of uptake rate constants for PCB congeners accumulated by semipermeable membrane devices and brown treat (Salmo trutta)

Science.gov (United States)

Meadows, J.C.; Echols, K.R.; Huckins, J.N.; Borsuk, F.A.; Carline, R.F.; Tillitt, D.E.

1998-01-01

The triolein-filled semipermeable membrane device (SPMD) is a simple and effective method of assessing the presence of waterborne hydrophobic chemicals. Uptake rate constants for individual chemicals are needed to accurately relate the amounts of chemicals accumulated by the SPMD to dissolved water concentrations. Brown trout and SPMDs were exposed to PCB- contaminated groundwater in a spring for 28 days to calculate and compare uptake rates of specific PCB congeners by the two matrixes. Total PCB congener concentrations in water samples from the spring were assessed and corrected for estimated total organic carbon (TOC) sorption to estimate total dissolved concentrations. Whole and dissolved concentrations averaged 4.9 and 3.7 ??g/L, respectively, during the exposure. Total concentrations of PCBs in fish rose from 0.06 to 118.3 ??g/g during the 28-day exposure, while concentrations in the SPMD rose from 0.03 to 203.4 ??g/ g. Uptake rate constants (k1) estimated for SPMDs and brown trout were very similar, with k1 values for SPMDs ranging from one to two times those of the fish. The pattern of congener uptake by the fish and SPMDs was also similar. The rates of uptake generally increased or decreased with increasing K(ow), depending on the assumption of presence or absence of TOC.The triolein-filled semipermeable membrane device (SPMD) is a simple and effective method of assessing the presence of waterborne hydrophobic chemicals. Uptake rate constants for individual chemicals are needed to accurately relate the amounts of chemicals accumulated by the SPMB to dissolved water concentrations. Brown trout and SPMDs were exposed to PCB-contaminated groundwater in a spring for 28 days to calculate and compare uptake rates of specific PCB congeners by the two matrixes. Total PCB congener concentrations in water samples from the spring were assessed and corrected for estimated total organic carbon (TOC) sorption to estimate total dissolved concentrations. Whole and

ENVIRONMENTAL PCB AND PESTICIDE EXPOSURE AND RISK OF ENDOMETRIOSIS

Science.gov (United States)

Environmental PCB and Pesticide Exposure and Risk of EndometriosisGermaine M. Buck1, John M. Weiner2, Hebe Greizerstein3, Brian Whitcomb1, Enrique Schisterman1, Paul Kostyniak3, Danelle Lobdell4, Kent Crickard5, and Ralph Sperrazza51Epidemiology Branch, Division o...

miR-126 is downregulated in cystic fibrosis airway epithelial cells and regulates TOM1 expression.

LENUS (Irish Health Repository)

Oglesby, Irene K

2010-02-15

Cystic fibrosis (CF) is one of the most common lethal genetic diseases in which the role of microRNAs has yet to be explored. Predicted to be regulated by miR-126, TOM1 (target of Myb1) has been shown to interact with Toll-interacting protein, forming a complex to regulate endosomal trafficking of ubiquitinated proteins. TOM1 has also been proposed as a negative regulator of IL-1beta and TNF-alpha-induced signaling pathways. MiR-126 is highly expressed in the lung, and we now show for the first time differential expression of miR-126 in CF versus non-CF airway epithelial cells both in vitro and in vivo. MiR-126 downregulation in CF bronchial epithelial cells correlated with a significant upregulation of TOM1 mRNA, both in vitro and in vivo when compared with their non-CF counterparts. Introduction of synthetic pre-miR-126 inhibited luciferase activity in a reporter system containing the full length 3\\'-untranslated region of TOM1 and resulted in decreased TOM1 protein production in CF bronchial epithelial cells. Following stimulation with LPS or IL-1beta, overexpression of TOM1 was found to downregulate NF-kappaB luciferase activity. Conversely, TOM1 knockdown resulted in a significant increase in NF-kappaB regulated IL-8 secretion. These data show that miR-126 is differentially regulated in CF versus non-CF airway epithelial cells and that TOM1 is a miR-126 target that may have an important role in regulating innate immune responses in the CF lung. To our knowledge, this study is the first to report of a role for TOM1 in the TLR2\\/4 signaling pathways and the first to describe microRNA involvement in CF.

Sampling of BTX in Hat Yai city using cost effective laboratory-built PCB passive sampler.