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Sample records for biphenyls increase reactive

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

    International Nuclear Information System (INIS)

    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.

  2. Reactivity of polychlorinated biphenyls in nucleophilic and electrophilic substitutions

    Energy Technology Data Exchange (ETDEWEB)

    Gorbunova, Tatyana I., E-mail: gorbunova@ios.uran.ru [I. Ya. Postovskii Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, Kovalevskoy St., 22, Ekaterinburg 620990 (Russian Federation); Subbotina, Julia O. [Ural Federal University named after the first President of Russia B.N. Yeltsin, Mira St., 19, Ekaterinburg 620002 (Russian Federation); Saloutin, Viktor I.; Chupakhin, Oleg N. [I. Ya. Postovskii Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences, Kovalevskoy St., 22, Ekaterinburg 620990 (Russian Federation)

    2014-08-15

    Graphical abstract: - Highlights: • Quantum chemical calculations were carried out for PCBs congeners. • Calculated descriptors were used to explain the PCBs reactivity in S{sub N} and S{sub E} substitutions. • Obtained data were used to estimate the PCBs reactivity in the S{sub N} reactions. • Calculated descriptors were insufficient to explain the PCBs reactivity in the S{sub E} reactions. • New neutralization methods of the large-capacity PCBs were discussed. - Abstract: To explain the chemical reactivity of polychlorinated biphenyls in nucleophilic (S{sub N}) and electrophilic (S{sub E}) substitutions, quantum chemical calculations were carried out at the B3LYP/6-31G(d) level of the Density Functional Theory in gas phase. Carbon atomic charges in biphenyl structure were calculated by the Atoms-in-Molecules method. Chemical hardness and global electrophilicity index parameters were determined for congeners. A comparison of calculated descriptors and experimental data for congener reactivity in the S{sub N} and S{sub E} reactions was made. It is shown that interactions in the S{sub N} mechanism are reactions of the hard acid–hard base type, these are the most effective in case of highly chlorinated substrates. To explain the congener reactivity in the S{sub E} reactions, correct descriptors were not established. The obtained results can be used to carry out chemical transformations of the polychlorinated biphenyls in order to prepare them for microbiological destruction or preservation.

  3. Critical evaluation of polychlorinated biphenyl toxicity in terrestrial and marine mammals: increasing impact of non-ortho and mono-ortho coplanar polychlorinated biphenyls from land to ocean.

    Science.gov (United States)

    Kannan, N; Tanabe, S; Ono, M; Tatsukawa, R

    1989-11-01

    Residues of potentially toxic non-ortho chlorine substituted coplanar 3,3',4,4'-tetra-,3,3',4,4',5-penta-, 3,3',4,4',5,5'-hexachlorobiphenyl and their mono- and di-ortho analogs 2,3',4,4',5-penta, 2,3,3',4,4'-penta-, 2,3,3',4,4',5-hexa- and 2,2',3,3',4,4'-hexa-, 2,2',3,4,4',5-hexachlorobiphenyl) were determined in humans, dogs, cats (terrestrial), a finless porpoise (Neophocoena phocoenoides--coastal), Dall's porpoises (Phocoenoides dalli, dalli), Baird's beaked whales (Berardius bairdii) and killer whales (Orcinus orca--open ocean). Among the coplanar polychlorinated biphenyl (PCB) congeners, the concentration of the di-ortho congeners was the highest and the non-ortho congeners was the lowest. However, all three coplanar PCBs occurred at significantly higher levels than toxic polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The relative bioconcentration and metabolic capacity of terrestrial and marine mammals to these chemicals, suggest that the toxic threat of coplanar PCBs increases from land to ocean, but the reverse is true for PCDDs and PCDFs. The toxic threat of coplanar PCBs to higher aquatic predators such as cetaceans was principally assessed by 2,3,7,8-T4CDD Toxic Equivalent Analysis which is based on the induction of arylhydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD). Analysis indicates, in particular, that the bioaccumulation of toxic 3,3',4,4',5-penta- and 2,3,3',4,4'-pentachlorobiphenyls in carnivorous marine mammals is a cause for considerable concern. PMID:2515809

  4. Engineering of pyranose dehydrogenase for increased oxygen reactivity.

    Directory of Open Access Journals (Sweden)

    Iris Krondorfer

    Full Text Available Pyranose dehydrogenase (PDH, a member of the GMC family of flavoproteins, shows a very broad sugar substrate specificity but is limited to a narrow range of electron acceptors and reacts extremely slowly with dioxygen as acceptor. The use of substituted quinones or (organometals as electron acceptors is undesirable for many production processes, especially of food ingredients. To improve the oxygen reactivity, site-saturation mutagenesis libraries of twelve amino acids around the active site of Agaricus meleagris PDH were expressed in Saccharomyces cerevisiae. We established high-throughput screening assays for oxygen reactivity and standard dehydrogenase activity using an indirect Amplex Red/horseradish peroxidase and a DCIP/D-glucose based approach. The low number of active clones confirmed the catalytic role of H512 and H556. Only one position was found to display increased oxygen reactivity. Histidine 103, carrying the covalently linked FAD cofactor in the wild-type, was substituted by tyrosine, phenylalanine, tryptophan and methionine. Variant H103Y was produced in Pichia pastoris and characterized and revealed a five-fold increase of the oxygen reactivity.

  5. Penultimate effect in ethylene-styrene copolymerization and the discovery of highly active ethylene-styrene catalysts with increased styrene reactivity.

    Science.gov (United States)

    Arriola, Daniel J; Bokota, Marilyn; Campbell, Richard E; Klosin, Jerzy; LaPointe, Robert E; Redwine, O David; Shankar, Ravi B; Timmers, Francis J; Abboud, Khalil A

    2007-06-01

    For the first time commercially relevant catalysts for the copolymerization of ethylene and styrene have been identified. The catalysts maintain very high copolymer efficiencies at relatively high reactor temperatures without sacrificing styrene comonomer reactivity. The observations which led to this discovery are based upon the kinetic analysis of ethylene-styrene copolymerization using constrained geometry catalyst (eta5-C5Me4)(SiMe2-N-t-Bu)TiMe2 (1). This analysis revealed a substantial styrene penultimate monomer effect. Inherent reactivity of 1 toward styrene is greatly improved when the penultimate monomer on the growing polymer chain is styrene rather than ethylene. The presence of a penultimate styrene effect led to the hypothesis that catalysts bearing aromatic moieties in close proximity to the active site could lead to enhancement of styrene reactivity for this catalyst family. This hypothesis was born out by two new constrained geometry catalysts, one having two phenyl substituents placed in the 3 and 3' positions of the Cp ring (2) and the other with a 2,2'-biphenyl fragment attached to the Cp ring (3). Both catalysts exhibit higher activity than that of 1 and, more importantly, much higher styrene reactivity leading to copolymers with substantially increased styrene content (21.5% for 2, 30.6% for 3) as compared to 1 (11%) under the same polymerization conditions. Analysis of the X-ray crystal structures of 2 and 3 shows no overriding structural arguments for the increased performance. Outstanding polymerization characteristics achieved with 3 make this catalyst a candidate for commercial production of ethylene-styrene resins in a solution process. PMID:17489593

  6. Increased Body Mass Index, Elevated C-reactive Protein, and Short Telomere Length

    DEFF Research Database (Denmark)

    Rode, Line; Nordestgaard, Børge G; Weischer, Maren; Bojesen, Stig E

    2014-01-01

    protein. SETTING AND DESIGN: We studied 45,069 individuals from the Copenhagen General Population Study with measurements of leukocyte telomere length, BMI, and C-reactive protein in a Mendelian randomization study. Using the three obesity-associated polymorphisms FTO rs9939609, MC4R rs17782313, and TMEM......18 rs6548238, and the CRP promoter polymorphism rs3091244 in instrumental variable analyses, we estimated the associations between genetically increased BMI and telomere length and between genetically increased C-reactive protein and telomere length. RESULTS: In multivariable-adjusted observational...... analyses, telomere length decreased with seven base pairs (95% confidence interval, -9--5) per unit increase in BMI, and further adjustment for C-reactive protein attenuated this association to -5 base pairs (-8--3). In accordance, instrumental variable analysis showed a non-significant telomere length...

  7. Increased Baseline C-Reactive Protein Concentrations Are Associated with Increased Risk of Infections

    DEFF Research Database (Denmark)

    Zacho, Jeppe; Benfield, Thomas; Tybjærg-Hansen, Anne;

    2016-01-01

    CRP tertile (compared with the lowest) had an increased risk of bacterial diseases (hazard ratio 1.7, 95% CI 1.6-1.8), but not viral, mycosis, and parasitic diseases. The increased risk was mainly carried by pneumonia, sepsis, and particularly gram-negative infections. None of the genotype...

  8. Estimated Reactivity Increase of Spent Fuel Pool Criticality during Transfer of Fuel Element

    International Nuclear Information System (INIS)

    The spent fuel pool (SFP) planned for Reaktor TRIGA PUSPATI (RTP) are designed to be far below criticality. Acts of withdrawing or inserting more fuel into the SFP shall add a certain amount of reactivity into the system. This paper investigates the amount of reactivity increase or decrease due to insertion of fuel, withdrawal of fuel, insertion of a rack full of fuel and also the withdrawal of this fuel filled rack. This knowledge is essential for the safe handling of the fuel on route to the SFP. (author)

  9. Mitohormesis: Promoting Health and Lifespan by Increased Levels of Reactive Oxygen Species (ROS)

    OpenAIRE

    Ristow, Michael; Schmeisser, Kathrin

    2014-01-01

    Increasing evidence indicates that reactive oxygen species (ROS), consisting of superoxide, hydrogen peroxide, and multiple others, do not only cause oxidative stress, but rather may function as signaling molecules that promote health by preventing or delaying a number of chronic diseases, and ultimately extend lifespan. While high levels of ROS are generally accepted to cause cellular damage and to promote aging, low levels of these may rather improve systemic defense mechanisms by inducing ...

  10. Exploring the Potential for Increased Production from the Wave Energy Converter Lifesaver by Reactive Control

    OpenAIRE

    Marta Molinas; Jonas Sjolte; Christian McLisky Sandvik; Elisabetta Tedeschi

    2013-01-01

    Fred Olsen is currently testing their latest wave energy converter (WEC), Lifesaver, outside of Falmouth Bay in England, preparing it for commercial operation at the Wavehub test site. Previous studies, mostly focusing on hydrodynamics and peak to average power reduction, have shown that this device has potential for increased power extraction using reactive control. This article extends those analyses, adding a detailed model of the all-electric power take-off (PTO) system, consisting of a p...

  11. Metabolism and metabolites of polychlorinated biphenyls (PCBs)

    OpenAIRE

    Grimm, FA; Hu, D.; Kania-Korwel, I.; Lehmler, HJ; Ludewig, G; Hornbuckle, KC; Duffel, MW; Bergman, A; Robertson, LW

    2015-01-01

    The metabolism of polychlorinated biphenyls (PCBs) is complex and has an impact on toxicity and thereby assessment of PCB risks. A large number of reactive and stable metabolites are formed in the processes of biotransformation in biota in general and in humans in particular. The aim of this document is to provide an overview of PCB metabolism and to identify metabolites of concern and their occurrence. Emphasis is given to mammalian metabolism of PCBs and their hydroxyl, methylsulfonyl, and ...

  12. Acrolein activates matrix metalloproteinases by increasing reactive oxygen species in macrophages

    International Nuclear Information System (INIS)

    Acrolein is a ubiquitous component of environmental pollutants such as automobile exhaust, cigarette, wood, and coal smoke. It is also a natural constituent of several foods and is generated endogenously during inflammation or oxidation of unsaturated lipids. Because increased inflammation and episodic exposure to acrolein-rich pollutants such as traffic emissions or cigarette smoke have been linked to acute myocardial infarction, we examined the effects of acrolein on matrix metalloproteinases (MMPs), which destabilize atherosclerotic plaques. Our studies show that exposure to acrolein resulted in the secretion of MMP-9 from differentiated THP-1 macrophages. Acrolein-treatment of macrophages also led to an increase in reactive oxygen species (ROS), free intracellular calcium ([Ca2+]i), and xanthine oxidase (XO) activity. ROS production was prevented by allopurinol, but not by rotenone or apocynin and by buffering changes in [Ca2+]I with BAPTA-AM. The increase in MMP production was abolished by pre-treatment with the antioxidants Tiron and N-acetyl cysteine (NAC) or with the xanthine oxidase inhibitors allopurinol or oxypurinol. Finally, MMP activity was significantly stimulated in aortic sections from apoE-null mice containing advanced atherosclerotic lesions after exposure to acrolein ex vivo. These observations suggest that acrolein exposure results in MMP secretion from macrophages via a mechanism that involves an increase in [Ca2+]I, leading to xanthine oxidase activation and an increase in ROS production. ROS-dependent activation of MMPs by acrolein could destabilize atherosclerotic lesions during brief episodes of inflammation or pollutant exposure.

  13. Forebrain Glucocorticoid Receptor Overexpression Increases Environmental Reactivity and Produces a Stress-Induced Spatial Discrimination Deficit

    OpenAIRE

    Hebda-Bauer, Elaine K.; Pletsch, Amy; Darwish, Hala; Fentress, Hugh; Simmons, Tracy A.; Wei, Qiang (Ethan); Watson, Stanley J.; Akil, Huda

    2010-01-01

    Reactivity to environmental stressors influences vulnerability to neurological and psychiatric illnesses, but little is known about molecular mechanisms that control this reactivity. Since mice with forebrain-specific glucocorticoid receptor overexpression (GRov mice) display anxiety-like behaviors in novel environments and have difficulty adjusting to change in memory tasks, we hypothesized that these may be facets of a broader phenotype of altered reactivity to environmental demands. Male G...

  14. Age increases anxiety and reactivity of the fear/anxiety circuit in Lewis rats.

    Science.gov (United States)

    Meyza, Ksenia Z; Boguszewski, Pawel M; Nikolaev, Evgeni; Zagrodzka, Jolanta

    2011-11-20

    A growing body of data indicates that changes in emotional behavior occur with age. Young Lewis rats are known to display hypofunction of the HPA axis. With age the reactivity of this axis is thought to increase with a concomitant rise in anxiety. In the current study, we investigate how and if the pattern of neuronal activation (measured as c-Fos protein expression) in Lewis rat brains changes with age and in response to novel environments differing in aversiveness. We found that distinct parts of the fear/anxiety circuit (i.e., the amygdalar complex, hippocampus and hypothalamus) undergo diverse age-related changes in response to behavioral challenges. While in the hypothalamus an increase in responsivity to mild stressors was observed with age, no such effect was present in the hippocampus. The amygdalar complex (especially the medial and cortical nuclei) on the other hand exhibited an age-dependent decrease in neuronal activation to mild stressors. This was accompanied by a marked increase in anxiety not correlated with a decline in locomotor activity. PMID:21782853

  15. Increase of ambient formaldehyde in Beijing and its implication for VOC reactivity

    Institute of Scientific and Technical Information of China (English)

    Qian Zhang; Min Shao; Yang Li; Si Hua Lu; Bin Yuan; Wen Tai Chen

    2012-01-01

    Influencing atmospheric OH radical budget and tropospheric ozone production,ambient formaldehyde (HCHO) is one of the key oxygenated volatile organic compounds (OVOCs).We present the variations on formaldehyde column densities in summertime in Beijing retrieved from ozone monitoring instrument (OMI) between 2005 and 2011.Satellite columns of HCHO correlated well with available ground-based measurements despite some noticeable differences.The orthogonal distance regression (ODR) method was used to estimate the ratio between satellite columns and ground-level concentrations,whereas ordinary least squares (OLS)method was used to fit the trend of ambient formaldehyde.The formaldehyde concentrations derived from HCHO columns were in the range of 7-12 ppbv and steadily increased at an approximate rate of 0.64 ppbv/yr (7.8% at 2005 level) with an uncertainty of 51%.VOC reactivity quantified by means of OH loss rates showed increasing contribution from formaldehyde and acetaldehyde,rising from 35% in 2005 to 40% in 2010,and decreasing contribution from anthropogenic VOCs,dropping from 49% in 2005 to 40% in 2010.More attention should be paid to understanding the net feedback of increasing formaldehyde to ozone formation potential.

  16. Reactive oxygen species mediate TNFR1 increase after TRPV1 activation in mouse DRG neurons

    Directory of Open Access Journals (Sweden)

    Westlund Karin N

    2009-06-01

    Full Text Available Abstract Background Transient receptor potential vanilloid subtype 1 (TRPV1 is activated by low pH/protons and is well known to be involved in hyperalgesia during inflammation. Tumor necrosis factor α (TNF-α, a proinflammatory cytokine, is involved in nociceptive responses causing hyperalgesia through TNF receptor type 1 (TNFR1 activation. Reactive oxygen species (ROS production is also prominently increased in inflamed tissue. The present study investigated TNFR1 receptors in primary cultured mouse dorsal root ganglion (DRG neurons after TRPV1 activation and the involvement of ROS. C57BL/6 mice, both TRPV1 knockout and wild type, were used for immunofluorescent and live cell imaging. The L4 and L5 DRGs were dissected bilaterally and cultured overnight. TRPV1 was stimulated with capsaicin or its potent analog, resiniferatoxin. ROS production was measured with live cell imaging and TNFR1 was detected with immunofluorescence in DRG primary cultures. The TRPV1 knockout mice, TRPV1 antagonist, capsazepine, and ROS scavenger, N-tert-Butyl-α-phenylnitrone (PBN, were employed to explore the functional relationship among TRPV1, ROS and TNFR1 in these studies. Results The results demonstrate that TRPV1 activation increases TNFR1 receptors and ROS generation in primary cultures of mouse DRG neurons. Activated increases in TNFR1 receptors and ROS production are absent in TRPV1 deficient mice. The PBN blocks increases in TNFR1 and ROS production induced by capsaicin/resiniferatoxin. Conclusion TRPV1 activation increases TNFR1 in cultured mouse DRG neurons through a ROS signaling pathway, a novel sensitization mechanism in DRG neurons.

  17. Increased Reactive Oxygen Species Formation and Oxidative Stress in Rheumatoid Arthritis

    Science.gov (United States)

    Mateen, Somaiya; Moin, Shagufta; Khan, Abdul Qayyum; Zafar, Atif; Fatima, Naureen

    2016-01-01

    Background Rheumatoid arthritis (RA) is an autoimmune inflammatory disorder. Highly reactive oxygen free radicals are believed to be involved in the pathogenesis of the disease. In this study, RA patients were sub-grouped depending upon the presence or absence of rheumatoid factor, disease activity score and disease duration. RA Patients (120) and healthy controls (53) were evaluated for the oxidant—antioxidant status by monitoring ROS production, biomarkers of lipid peroxidation, protein oxidation and DNA damage. The level of various enzymatic and non-enzymatic antioxidants was also monitored. Correlation analysis was also performed for analysing the association between ROS and various other parameters. Methods Intracellular ROS formation, lipid peroxidation (MDA level), protein oxidation (carbonyl level and thiol level) and DNA damage were detected in the blood of RA patients. Antioxidant status was evaluated by FRAP assay, DPPH reduction assay and enzymatic (SOD, catalase, GST, GR) and non-enzymatic (vitamin C and GSH) antioxidants. Results RA patients showed a higher ROS production, increased lipid peroxidation, protein oxidation and DNA damage. A significant decline in the ferric reducing ability, DPPH radical quenching ability and the levels of antioxidants has also been observed. Significant correlation has been found between ROS and various other parameters studied. Conclusion RA patients showed a marked increase in ROS formation, lipid peroxidation, protein oxidation, DNA damage and decrease in the activity of antioxidant defence system leading to oxidative stress which may contribute to tissue damage and hence to the chronicity of the disease. PMID:27043143

  18. Increased effectiveness of carbon ions in the production of reactive oxygen species in normal human fibroblasts

    International Nuclear Information System (INIS)

    The production of reactive oxygen species (ROS), especially superoxide anions (O2·-), is enhanced in many normal and tumor cell types in response to ionizing radiation. The influence of ionizing radiation on the regulation of ROS production is considered as an important factor in the long-term effects of irradiation (such as genomic instability) that might contribute to the development of secondary cancers. In view of the increasing application of carbon ions in radiation therapy, we aimed to study the potential impact of ionizing density on the intracellular production of ROS, comparing photons (X-rays) with carbon ions. For this purpose, we used normal human cells as a model for irradiated tissue surrounding a tumor. By quantifying the oxidization of Dihydroethidium (DHE), a fluorescent probe sensitive to superoxide anions, we assessed the intracellular ROS status after radiation exposure in normal human fibroblasts, which do not show radiation-induced chromosomal instability. After 3–5 days post exposure to X-rays and carbon ions, the level of ROS increased to a maximum that was dose dependent. The maximum ROS level reached after irradiation was specific for the fibroblast type. However, carbon ions induced this maximum level at a lower dose compared with X-rays. Within ∼1 week, ROS decreased to control levels. The time-course of decreasing ROS coincides with an increase in cell number and decreasing p21 protein levels, indicating a release from radiation-induced growth arrest. Interestingly, radiation did not act as a trigger for chronically enhanced levels of ROS months after radiation exposure. (author)

  19. Increase of reactive oxygen species by desferrioxamine during experimental Chagas' disease

    Science.gov (United States)

    Francisco, Amanda Fortes; de Abreu Vieira, Paula Melo; Arantes, Jerusa Marilda; Silva, Maisa; Pedrosa, Maria Lúcia; Elói-Santos, Silvana Maria; Martins-Filho, Olindo Assis; Teixeira-Carvalho, Andréa; Araújo, Márcio Sobreira Silva; Tafuri, Washington Luiz; Carneiro, Cláudia Martins

    2010-01-01

    Oxidative stress is common in inflammatory processes associated with many diseases including Chagas' disease. The aim of the present study was to evaluate, in a murine model, biomarkers of oxidative stress together with components of the antioxidant system in order to provide an overview of the mechanism of action of the iron chelator desferrioxamine (DFO). The study population comprised 48 male Swiss mice, half of which were treated daily by intraperitoneal injection of DFO over a 35-day period, while half were administered sterile water in a similar manner. On the 14th day of the experiment, 12 DFO-treated mice and an equal number of untreated mice were experimentally infected with Trypanosoma cruzi. Serum concentrations of nitric oxide and superoxide dismutase and hepatic levels of total glutathione, thiobarbituric acid reactive species and protein carbonyl, were determined on days 0, 7, 14 and 21 post-infection. The results obtained revealed that DFO enhances antioxidant activity in the host but also increases oxidative stress, indicating that the mode of action of the drug involves a positive contribution to the host together with an effect that is not beneficial to the parasite. PMID:20663295

  20. Types of oil shale ash and methods for increasing their reactivity

    International Nuclear Information System (INIS)

    Ash from the combustion of powdered Estonian oil shale in power plants has a high chemical reactivity and ability to bind hazardous components in the waste from the Sillamaee plant. This characteristic suggests that the ash should be considered as a component of a barrier system for remediation of the tailings pond. Different types of ash, collected in different parts of a power plant, show different reactivities

  1. Mechanistic insights on the hydrodesulfurization of biphenyl-2-thiol with nickel compounds.

    Science.gov (United States)

    Torres-Nieto, Jorge; Brennessel, William W; Jones, William D; García, Juventino J

    2009-03-25

    The reactivity of the nickel(I) dimer [(dippe)Ni(mu-H)](2) (1) with biphenyl-2-thiol was explored with the aim of clarifying the key step of sulfur extrusion during the hydrodesulfurization process using dibenzothiophene (DBT). These reactions were monitored by variable temperature NMR experiments which allowed the complete characterization and isolation of [(dippe)(2)Ni(2)(mu-H)(mu-S-2-biphenyl)] (3). The latter compound evolves to the terminal nickel-hydride [(dippe)Ni (eta(1)-C-2-biphenyl)(H)] (4) and transient [(dippe)NiS] (5), to ultimately yield [(dippe)(2)Ni(2)(mu-S)] (2) and biphenyl as the resulting HDS products. The reactivity of 1 and biphenyl-2-thiol was examined using different ratios of reactants, which allowed preparation of [(dippe)Ni(eta(1)-S-biphenyl-2-thiolate)(2)] (6) when using an excess of this substrate. The reactivity of 6 with 1 was addressed, yielding compound 2 and an equivalent amount of biphenyl. PMID:19292493

  2. Increased airway reactivity in a neonatal mouse model of Continuous Positive Airway Pressure (CPAP)

    OpenAIRE

    Mayer, Catherine A; Martin, Richard J.; MacFarlane, Peter M.

    2015-01-01

    Background Continuous positive airway pressure (CPAP) is a primary form of respiratory support used in the intensive care of preterm infants, but its long-term effects on airway (AW) function are unknown. Methods We developed a neonatal mouse model of CPAP treatment to determine whether it modifies later AW reactivity. Un-anesthetized spontaneously breathing mice were fitted with a mask to deliver CPAP (6cmH2O, 3hrs/day) for 7 consecutive days starting at postnatal day 1. Airway reactivity to...

  3. Thermic decomposition of biphenyl

    International Nuclear Information System (INIS)

    Liquid and vapour phase pyrolysis of very pure biphenyl obtained by methods described in the text was carried out at 400 C in sealed ampoules, the fraction transformed being always less than 0.1 per cent. The main products were hydrogen, benzene, terphenyls, and a deposit of polyphenyls strongly adhering to the walls. Small quantities of the lower aliphatic hydrocarbons were also found. The variation of the yields of these products with a) the pyrolysis time, b) the state (gas or liquid) of the biphenyl, and c) the pressure of the vapour was measured. Varying the area and nature of the walls showed that in the absence of a liquid phase, the pyrolytic decomposition takes place in the adsorbed layer, and that metallic walls promote the reaction more actively than do those of glass (pyrex or silica). A mechanism is proposed to explain the results pertaining to this decomposition in the adsorbed phase. The adsorption seems to obey a Langmuir isotherm, and the chemical act which determines the overall rate of decomposition is unimolecular. (author)

  4. How a gold substrate can increase the reactivity of a Pt overlayer

    DEFF Research Database (Denmark)

    Pedersen, Morten Ø.; Helveg, Stig; Ruban, Andrei;

    1999-01-01

    which 3% of the Au atoms are replaced by Pt. Subsequent Pt evaporation leads to island growth with a mixed Pt-Au island composition. The reactivity of the Pt/Au system is studied using CO as a probe molecule. We show that a stronger bonding of CO to the first layer of Pt on Au(111) exists compared with......The growth and chemical reactivity of Pt on Au(111) have been studied using scanning tunneling microscopy (STM) and temperature programmed desorption (TPD). Deposition of Pt at coverages from 0.02 ML up to 2.5 ML on Au(111) at room temperature initially leads to the formation of a surface alloy, in...

  5. Reversal of HO-1 related cytoprotection with increased expression is due to reactive iron.

    Science.gov (United States)

    Suttner, D M; Dennery, P A

    1999-10-01

    It is often postulated that the cytoprotective nature of heme oxygenase (HO-1) explains the inducible nature of this enzyme. However, the mechanisms by which protection occurs are not verified by systematic evaluation of the physiological effects of HO. To explain how induction of HO-1 results in protection against oxygen toxicity, hamster fibroblasts (HA-1) were stably transfected with a tetracycline response plasmid containing the full-length rat HO-1 cDNA construct to allow for regulation of gene expression by varying concentrations of doxycycline (Dox). Transfected cells were exposed to hyperoxia (95% O(2)/5% CO2) for 24 h and several markers of oxidative injury were measured. With varying concentrations of Dox, HO activity was regulated between 3- and 17-fold. Despite cytoprotection with low (less than fivefold) HO activity, high levels of HO-1 expression (greater than 15-fold) were associated with significant oxygen cytotoxicity. Levels of non-heme reactive iron correlated with cellular injury in hyperoxia whereas lower levels of heme were associated with cytoprotection. Cellular levels of cyclic GMP and bilirubin were not significantly altered by modification of HO activity, precluding a substantial role for activation of guanylate cyclase by carbon monoxide or for accumulation of bile pigments in the physiological consequences of HO-1 overexpression. Inhibition of HO activity or chelation of cellular iron prior to hyperoxic exposure decreased reactive iron levels in the samples and significantly reduced oxygen toxicity. We conclude that there is a beneficial threshold of HO-1 overexpression related to the accumulation of reactive iron released in the degradation of heme. Therefore, despite the ready induction of HO-1 in oxidant stress, accumulation of reactive iron formed makes it unlikely that exaggerated expression of HO-1 is a cytoprotective response. PMID:10506583

  6. C-reactive protein increases plasminogen activator inhibitor–1 expression in human endothelial cells

    OpenAIRE

    Chen, Changyi; Nan, Bicheng; Lin, Peter; Yao, Qizhi

    2007-01-01

    C-reactive protein (CRP) is an inflammatory marker which predicts cardiovascular disease. However, it is not fully understood whether CRP has direct effects on endothelial functions and gene expression. The purpose of current study was to determine the effects and molecular mechanisms of CRP on the expression of plasminogen activator inhibitor-1 (PAI-1) in human endothelial cells. Human coronary artery endothelial cells (HCAEC) were treated with CRP at clinically relevant concentrations for d...

  7. Emotion Reactivity Is Increased 4-6 Weeks Postpartum in Healthy Women: A Longitudinal fMRI Study.

    Directory of Open Access Journals (Sweden)

    Malin Gingnell

    Full Text Available Marked endocrine alterations occur after delivery. Most women cope well with these changes, but the postpartum period is associated with an increased risk of depressive episodes. Previous studies of emotion processing have focused on maternal-infant bonding or postpartum depression (PPD, and longitudinal studies of the neural correlates of emotion processing throughout the postpartum period in healthy women are lacking. In this study, 13 women, without signs of post partum depression, underwent fMRI with an emotional face matching task and completed the MADRS-S, STAI-S, and EPDS within 48 h (early postpartum and 4-6 weeks after delivery (late postpartum. Also, data from a previous study including 15 naturally cycling controls assessed in the luteal and follicular phase of the menstrual cycle was used. Women had lower reactivity in insula, middle frontal gyrus (MFG, and inferior frontal gyrus (IFG in the early as compared to the late postpartum assessment. Insular reactivity was positively correlated with anxiety in the early postpartum period and with depressive symptoms late postpartum. Reactivity in insula and IFG were greater in postpartum women than in non-pregnant control subjects. Brain reactivity was not correlated with serum estradiol or progesterone levels. Increased reactivity in the insula, IFG, and MFG may reflect normal postpartum adaptation, but correlation with self-rated symptoms of depression and anxiety in these otherwise healthy postpartum women, may also suggest that these changes place susceptible women at increased risk of PPD. These findings contribute to our understanding of the neurobiological aspects of the postpartum period, which might shed light on the mechanisms underlying affective puerperal disorders, such as PPD.

  8. Does elevated C-reactive protein increase atrial fibrillation risk? A Mendelian randomization of 47,000 individuals from the general population

    DEFF Research Database (Denmark)

    2010-01-01

    The purpose of this study was to test whether the association of C-reactive protein (CRP) with increased risk of atrial fibrillation is a robust and perhaps even causal association.......The purpose of this study was to test whether the association of C-reactive protein (CRP) with increased risk of atrial fibrillation is a robust and perhaps even causal association....

  9. Does high C-reactive protein concentration increase atherosclerosis? The Whitehall II Study.

    Directory of Open Access Journals (Sweden)

    Mika Kivimäki

    Full Text Available BACKGROUND: C-reactive protein (CRP, a marker of systemic inflammation, is associated with risk of coronary events and sub-clinical measures of atherosclerosis. Evidence in support of this link being causal would include an association robust to adjustments for confounders (multivariable standard regression analysis and the association of CRP gene polymorphisms with atherosclerosis (Mendelian randomization analysis. METHODOLOGY/PRINCIPAL FINDINGS: We genotyped 3 tag single nucleotide polymorphisms (SNPs [+1444T>C (rs1130864; +2303G>A (rs1205 and +4899T>G (rs 3093077] in the CRP gene and assessed CRP and carotid intima-media thickness (CIMT, a structural marker of atherosclerosis, in 4941 men and women aged 50-74 (mean 61 years (the Whitehall II Study. The 4 major haplotypes from the SNPs were consistently associated with CRP level, but not with other risk factors that might confound the association between CRP and CIMT. CRP, assessed both at mean age 49 and at mean age 61, was associated both with CIMT in age and sex adjusted standard regression analyses and with potential confounding factors. However, the association of CRP with CIMT attenuated to the null with adjustment for confounding factors in both prospective and cross-sectional analyses. When examined using genetic variants as the instrument for serum CRP, there was no inferred association between CRP and CIMT. CONCLUSIONS/SIGNIFICANCE: Both multivariable standard regression analysis and Mendelian randomization analysis suggest that the association of CRP with carotid atheroma indexed by CIMT may not be causal.

  10. Degradation of polychlorinated biphenyls

    International Nuclear Information System (INIS)

    Polychlorinated biphenyls (PCB) are generally disposed of by incineration, an expensive and hazardous method. Moreover, in cases where the PCBs are a minor component of a nontoxic fluid, such as a dielectric fluid, incineration causes loss of the nontoxic fluid as well as the PCB. An alternative method for destroying PCBs is disclosed which is not only capable of detoxification of PCB-contaminated soils, sludges, and sediments, but can also remove PCBs from solution in a wide range of concentrations, permitting full recovery of the bulk of the solution free of PCBs. The process of the invention may be operated in a batch, continuous, or semicontinuous mode, and is advantageously used to detoxify organic liquids such as transformer oils. According to the invention, PCBs are chemically degraded by contact with a Lewis acid catalyst in a nonaqueous liquid medium, in the presence of a cation which combines with the chlorine on the PCB to form a solid chloride of the cation which will precipitate out from the liquid medium. Preferred Lewis acids are metal halides, particularly a combination of aluminum chloride and ferric chloride, and the preferred cation is potassium in the form of KOH. The Lewis acids may be supplied to the process by the adventitious corrosion of a vessel containing the PCB-contaminated matter. Experiments are described to illustrate the process of the invention. 3 figs

  11. Development of structural and optical properties of WOx films upon increasing oxygen partial pressure during reactive sputtering

    International Nuclear Information System (INIS)

    WOx films were prepared by reactive dc magnetron sputtering using tungsten target. Sputtering was carried out at a total pressure of 1.2 Pa using a mixture of argon plus oxygen in an effort to determine the influence of the oxygen partial pressure on structural and optical properties of the films. The deposition rate decreases significantly as the surface of the target is oxidized. X-Ray diffraction revealed the amorphous nature of all the films prepared at oxygen partial pressures higher than 1.71x10-3 Pa. For higher oxygen partial pressures, fully transparent films were deposited, which showed a slight increase in optical band gap with increasing oxygen partial pressure, while the refractive index was simultaneously decreased. -- Research highlights: → There are only a few detailed studies on the formation process of WOx films by reactive sputtering. → Examination of the properties of the substoichiometric tungsten oxides. → Examination of the effect of oxygen partial pressure on properties of WOx.

  12. Extracellular Vpr protein increases cellular permissiveness to human immunodeficiency virus replication and reactivates virus from latency.

    OpenAIRE

    Levy, D N; Refaeli, Y; Weiner, D B

    1995-01-01

    The vpr gene product of human immunodeficiency virus (HIV) and simian immunodeficiency virus is a virion-associated regulatory protein that has been shown using vpr mutant viruses to increase virus replication, particularly in monocytes/macrophages. We have previously shown that vpr can directly inhibit cell proliferation and induce cell differentiation, events linked to the control of HIV replication, and also that the replication of a vpr mutant but not that of wild-type HIV type 1 (HIV-1) ...

  13. ACROLEIN ACTIVATES MATRIX METALLOPROTEINASES BY INCREASING REACTIVE OXYGEN SPECIES IN MACROPHAGES

    OpenAIRE

    O’Toole, Timothy E.; Zheng, Yu-Ting; Hellmann, Jason; Conklin, Daniel J.; Barski, Oleg; Bhatnagar, Aruni

    2009-01-01

    Acrolein is a ubiquitous component of environmental pollutants such as automobile exhaust, cigarette, wood, and coal smoke. It is also a natural constituent of several foods and is generated endogenously during inflammation or oxidation of unsaturated lipids. Because increased inflammation and episodic exposure to acrolein-rich pollutants such as traffic emissions or cigarette smoke have been linked to acute myocardial infarction, we examined the effects of acrolein on matrix metalloproteinas...

  14. Increasing DG Capacity of Existing Networks through Reactive Power Control and Curtailment

    OpenAIRE

    Leisse, Ingmar; Samuelsson, Olof; Svensson, Jörgen

    2010-01-01

    Renewable energy sources (RES), especially wind turbines, have become more important during the last years. An increasing number of distributed generation (DG) units are connected to weak medium voltage distribution networks in rural areas where they have a large influence on the voltage and the line losses. Voltage rise is in this case often a limiting factor for the maximum amount of DG capacity. Already current wind turbines with a capacity of 2 MW can often not easily be co...

  15. Increased retest reactivity by both patch and use test with methyldibromoglutaronitrile in sensitized individuals

    DEFF Research Database (Denmark)

    Jensen, Charlotte D; Johansen, Jeanne Duus; Menné, Torkil;

    2006-01-01

    -exposure by both a patch test challenge and a use test with a liquid soap preserved with MDBGN. MDBGN dermatitis was elicited on the back and arms of sensitized individuals. One month later the previously eczematous areas were challenged with MDBGN. On the back, the test sites were patch-tested with a serial...... dilution of MDBGN and a use test was performed on the arms with an MDBGN-containing soap. A statistically significant increased response was seen on the areas with previous dermatitis on the back. Eight of the nine patients who developed dermatitis on the arms from the MDBGN-containing soap had an...

  16. Stream discharge events increase the reactive efficiency of the hyporheic zone of an in-stream gravel bar

    Science.gov (United States)

    Trauth, Nico; Schmidt, Christian; Fleckenstein, Jan H.

    2016-04-01

    temporarily lead to increased reactive efficiency (the ratio between solute consumption and solute influx) of the hyporheic zone by approximately 2.0 and 3.8 times for aerobic respiration and denitrification, respectively.

  17. Radiochemical decomposition of polychlorinated biphenyls in hexane

    International Nuclear Information System (INIS)

    Products of polychlorinated biphenyls (PCB) decomposition are analyzed with the aim of determining whether polychlorinated dibenzodioxins (PCDD) or dibenzafurans (PCDF) are formed during radition-chemical decomposition. It is shown that under irradiation of PCB Arochlor 1260 mixture with 10-2 mass % concentration decomposition degree equals 90.4 % at radiaion dose more than 6 Mrad. As the result of irradiation the content of relatively light PCB in the mixture increases and the content of irradiated mixture becomes close to the content of Arochlor 1242 mixture. Neitgher PCDD nor PCDE is detected on the products of PCB decomposition

  18. Germ-free mice deficient of reactive oxygen species have increased arthritis susceptibility.

    Science.gov (United States)

    Wing, Kajsa; Klocke, Katrin; Samuelsson, Annika; Holmdahl, Rikard

    2015-05-01

    The NADPH oxidase 2 (NOX2) complex is responsible for the production of ROS in phagocytic cells. Genetic defects in NOX2 lead to opportunistic infections and inflammatory manifestations such as granulomas in humans, also known as chronic granulomatous disease (CGD). This condition is mirrored in mice with defective ROS production and interestingly both species are predisposed to autoimmune diseases. An unresolved question is whether the hyper-inflammation and tendency to develop autoimmunity are secondary to the increased infections, or whether these are parallel phenomena. We generated germ-free ROS deficient Ncf1 mutant mice that when reared in specific pathogen-free condition, are highly susceptible to collagen-induced arthritis compared with wild-type mice. Strikingly, arthritis incidence and severity was almost identical in germ-free and specific pathogen-free ROS-deficient mice. In addition, partial reduction of the microbial flora by antibiotics treatment did not alter the disease course. Taken together, this shows that ROS has a clear immune regulatory function that is decoupled from its function in host defence. PMID:25689796

  19. Thermal decomposition of biphenyl (1963)

    International Nuclear Information System (INIS)

    The rates of formation of the decomposition products of biphenyl; hydrogen, methane, ethane, ethylene, as well as triphenyl have been measured in the vapour and liquid phases at 460 deg. C. The study of the decomposition products of biphenyl at different temperatures between 400 and 460 deg. C has provided values of the activation energies of the reactions yielding the main products of pyrolysis in the vapour phase. Product and Activation energy: Hydrogen 73 ± 2 kCal/Mole; Benzene 76 ± 2 kCal/Mole; Meta-triphenyl 53 ± 2 kCal/Mole; Biphenyl decomposition 64 ± 2 kCal/Mole; The rate of disappearance of biphenyl is only very approximately first order. These results show the major role played at the start of the decomposition by organic impurities which are not detectable by conventional physico-chemical analysis methods and the presence of which accelerates noticeably the decomposition rate. It was possible to eliminate these impurities by zone-melting carried out until the initial gradient of the formation curves for the products became constant. The composition of the high-molecular weight products (over 250) was deduced from the mean molecular weight and the dosage of the aromatic C - H bonds by infrared spectrophotometry. As a result the existence in tars of hydrogenated tetra, penta and hexaphenyl has been demonstrated. (author)

  20. Epstein-Barr virus infection induces bone resorption in apical periodontitis via increased production of reactive oxygen species.

    Science.gov (United States)

    Jakovljevic, Aleksandar; Andric, Miroslav; Miletic, Maja; Beljic-Ivanovic, Katarina; Knezevic, Aleksandra; Mojsilovic, Slavko; Milasin, Jelena

    2016-09-01

    Chronic inflammatory processes in periapical tissues caused by etiological agents of endodontic origin lead to apical periodontitis. Apart from bacteria, two herpesviruses, Epstein-Barr virus (EBV) and Human cytomegalovirus (HCMV) are recognized as putative pathogens in apical periodontitis. Although previous reports suggest the involvement of EBV in the pathogenesis of apical periodontitis, its exact role in periapical bone resorption has not yet been fully elucidated. We hypothesize that EBV infection in apical periodontitis is capable of inducing periapical bone resorption via stimulation of reactive oxygen species (ROS) overproduction. Increased levels of ROS induce expression of receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL). RANKL binding to receptor activator of nuclear factor κB (RANK) present on the surface of preosteoclasts induces their maturation and activation which consequently leads to bone resorption. The potential benefit of antiviral and antioxidant-based therapies in periapical bone resorption treatment remains to be assessed. PMID:27515196

  1. Thermal decomposition of biphenyl (1963); Decomposition thermique du biphenyle (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Clerc, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-06-15

    The rates of formation of the decomposition products of biphenyl; hydrogen, methane, ethane, ethylene, as well as triphenyl have been measured in the vapour and liquid phases at 460 deg. C. The study of the decomposition products of biphenyl at different temperatures between 400 and 460 deg. C has provided values of the activation energies of the reactions yielding the main products of pyrolysis in the vapour phase. Product and Activation energy: Hydrogen 73 {+-} 2 kCal/Mole; Benzene 76 {+-} 2 kCal/Mole; Meta-triphenyl 53 {+-} 2 kCal/Mole; Biphenyl decomposition 64 {+-} 2 kCal/Mole; The rate of disappearance of biphenyl is only very approximately first order. These results show the major role played at the start of the decomposition by organic impurities which are not detectable by conventional physico-chemical analysis methods and the presence of which accelerates noticeably the decomposition rate. It was possible to eliminate these impurities by zone-melting carried out until the initial gradient of the formation curves for the products became constant. The composition of the high-molecular weight products (over 250) was deduced from the mean molecular weight and the dosage of the aromatic C - H bonds by infrared spectrophotometry. As a result the existence in tars of hydrogenated tetra, penta and hexaphenyl has been demonstrated. (author) [French] Les vitesses de formation des produits de decomposition du biphenyle: hydrogene, methane, ethane, ethylene, ainsi que des triphenyles, ont ete mesurees en phase vapeur et en phase liquide a 460 deg. C. L'etude des produits de decomposition du biphenyle a differentes temperatures comprises entre 400 et 460 deg. C, a fourni les valeurs des energies d'activation des reactions conduisant aux principaux produits de la pyrolyse en phase vapeur. Produit et Energie d'activation: Hydrogene 73 {+-} 2 kcal/Mole; Benzene 76 {+-} 2 kcal/Mole; Metatriphenyle, 53 {+-} 2 kcal/Mole; Decomposition du biphenyle 64 {+-} 2

  2. Increased stress reactivity is associated with reduced hippocampal activity and neuronal integrity along with changes in energy metabolism.

    Science.gov (United States)

    Knapman, Alana; Kaltwasser, Sebastian F; Martins-de-Souza, Daniel; Holsboer, Florian; Landgraf, Rainer; Turck, Christoph W; Czisch, Michael; Touma, Chadi

    2012-02-01

    Patients suffering from major depression have repeatedly been reported to have dysregulations in hypothalamus-pituitary-adrenal (HPA) axis activity along with deficits in cognitive processes related to hippocampal and prefrontal cortex (PFC) malfunction. Here, we utilized three mouse lines selectively bred for high (HR), intermediate, or low (LR) stress reactivity, determined by the corticosterone response to a psychological stressor, probing the behavioral and functional consequences of increased vs. decreased HPA axis reactivity on the hippocampus and PFC. We assessed performance in hippocampus- and PFC-dependent tasks and determined the volume, basal activity, and neuronal integrity of the hippocampus and PFC using in vivo manganese-enhanced magnetic resonance imaging and proton magnetic resonance spectroscopy. The hippocampal proteomes of HR and LR mice were also compared using two-dimensional gel electrophoresis and mass spectrometry. HR mice were found to have deficits in the performance of hippocampus- and PFC-dependent tests and showed decreased N-acetylaspartate levels in the right dorsal hippocampus and PFC. In addition, the basal activity of the hippocampus, as assessed by manganese-enhanced magnetic resonance imaging, was reduced in HR mice. The three mouse lines, however, did not differ in hippocampal volume. Proteomic analysis identified several proteins that were differentially expressed in HR and LR mice. In accordance with the notion that N-acetylaspartate levels, in part, reflect dysfunctional mitochondrial metabolism, these proteins were found to be involved in energy metabolism pathways. Thus, our results provide further support for the involvement of a dysregulated HPA axis and mitochondrial dysfunction in the etiology and pathophysiology of affective disorders. PMID:22288479

  3. GGsTOP increases migration of human periodontal ligament cells in vitro via reactive oxygen species pathway.

    Science.gov (United States)

    Jiang, Ying; Wang, Xiang; Li, Ying; Mu, Sen; Zhou, Shuang; Liu, Yi; Zhang, Bin

    2016-05-01

    GGsTOP is a novel and selective inhibitor of gamma-glutamyl transferase (GGT), a cell-surface enzyme that has a key role in glutathione homeostasis and the maintenance of cellular reactive oxygen species (ROS). ROS are essential for wound healing. However, little is known about the molecular mechanisms underlying the inhibition of GGT by GGsTOP in human periodontal ligament cells (hPLCs). The present study assessed GGT expression in mouse periodontal ligament tissues, GGT activity in hPLCs, and the potential physiological effect of GGsTOP on hPLC migration. Immunohistochemical analysis confirmed that GGT was widely expressed in mouse periodontal ligament tissue. Treatment with GGsTOP was associated with greater proliferation and migration of hPLCs, and higher levels of cellular ROS compared with untreated hPLCs. However, the increase in intracellular ROS was attenuated in hPLCs co‑cultured with the anti‑oxidant N‑acetylcysteine (NAC), a precursor of glutathione. The higher ROS levels associated with GGsTOP treatment were in parallel with increases in the levels of type I collagen and alpha smooth muscle actin, which was inhibited in hPLCs co‑cultured with NAC. Thus, GGsTOP may promote hPLC migration and participate in the maintenance of the periodontal ligament apparatus via the ROS pathway. PMID:27035100

  4. Kazinol Q from Broussonetia kazinoki Enhances Cell Death Induced by Cu(ll through Increased Reactive Oxygen Species

    Directory of Open Access Journals (Sweden)

    Hsue-Yin Hsu

    2011-04-01

    Full Text Available The ability of the flavan kazinol Q (KQ to induce DNA breakage in the presence of Cu(II was examined by agarose gel electrophoresis using supercoiled plasmid DNA. In KQ-mediated DNA breakage reaction, the involvement of reactive oxygen species (ROS, H2O2 and O2 - was established by the inhibition of DNA breakage by catalase and revealed DNA breakage by superoxide dismutase (SOD. The cell viability of gastric carcinoma SCM-1 cells treated with various concentrations of KQ was significantly decreased by cotreatment with Cu(II. Treatment of SCM-1 cells with 300 μM Cu(II enhanced the necrosis induced by 100 μM KQ. Treatment of SCM-1 cells with 100 mM KQ in the presence of 300 mM Cu(II increased the generation of H2O2. Taken together, the above finding suggested that KQ cotreatment with Cu(II produced increased amounts of H2O2, thus enhancing subsequent cell death due to necrosis.

  5. Chronic Aldosterone Administration Causes NOX2-Mediated Increases In Reactive Oxygen Species Production and Endothelial Dysfunction in the Cerebral Circulation

    Science.gov (United States)

    CHRISSOBOLIS, Sophocles; DRUMMOND, Grant R.; FARACI, Frank M.; SOBEY, Christopher G.

    2014-01-01

    Objective An elevated plasma aldosterone level is an independent cardiovascular risk factor. Although excess aldosterone promotes cardiovascular disease, no studies have examined the effect of increased plasma aldosterone on the cerebral circulation. A major source of vascular reactive oxygen species (ROS) during cardiovascular disease is the NADPH oxidases. Because NOX2-containing NADPH oxidase (NOX2 oxidase) is highly expressed in cerebral endothelium, we postulated that it might contribute to ROS generation and vascular dysfunction in response to aldosterone. Here we examined the effect of aldosterone and NOX2 oxidase on ROS production and endothelial dysfunction in the cerebral circulation, and whether the effects of aldosterone are exacerbated in aged mice. Methods and Results In adult (average age ~24–25 wk) wild-type (WT) and Nox2-deficient (Nox2−/y) mice, neither vehicle nor aldosterone (0.28 mg/kg/day for 14 days) affected blood pressure (measured using tail-cuff). By contrast, aldosterone treatment reduced dilation of the basilar artery (measured using myography) to the endothelium-dependent agonist acetylcholine in WT mice (P0.05). Aldosterone increased basal and phorbol-dibutyrate stimulated superoxide production (measured using L-012-enhanced chemiluminesence) in cerebral arteries from WT but not Nox2−/y mice. In aged WT mice (average age ~70 wk), aldosterone treatment increased blood pressure, but had a similar effect on cerebral artery superoxide levels as in adult WT mice. Conclusions These data indicate that NOX2 oxidase mediates aldosterone-induced increases in ROS production and endothelial dysfunction in cerebral arteries from adult mice independently of blood pressure changes. Aldosterone-induced hypertension is augmented during aging. PMID:24991871

  6. Caffeine Ingestion Increases Estimated Glycolytic Metabolism during Taekwondo Combat Simulation but Does Not Improve Performance or Parasympathetic Reactivation.

    Directory of Open Access Journals (Sweden)

    João Paulo Lopes-Silva

    Full Text Available The aim of this study was to evaluate the effect of caffeine ingestion on performance and estimated energy system contribution during simulated taekwondo combat and on post-exercise parasympathetic reactivation.Ten taekwondo athletes completed two experimental sessions separated by at least 48 hours. Athletes consumed a capsule containing either caffeine (5 mg∙kg-1 or placebo (cellulose one hour before the combat simulation (3 rounds of 2 min separated by 1 min passive recovery, in a double-blind, randomized, repeated-measures crossover design. All simulated combat was filmed to quantify the time spent fighting in each round. Lactate concentration and rating of perceived exertion were measured before and after each round, while heart rate (HR and the estimated contribution of the oxidative (WAER, ATP-PCr (WPCR, and glycolytic (W[La-] systems were calculated during the combat simulation. Furthermore, parasympathetic reactivation after the combat simulation was evaluated through 1 taking absolute difference between the final HR observed at the end of third round and the HR recorded 60-s after (HRR60s, 2 taking the time constant of HR decay obtained by fitting the 6-min post-exercise HRR into a first-order exponential decay curve (HRRτ, or by 3 analyzing the first 30-s via logarithmic regression analysis (T30.Caffeine ingestion increased estimated glycolytic energy contribution in relation to placebo (12.5 ± 1.7 kJ and 8.9 ± 1.2 kJ, P = 0.04. However, caffeine did not improve performance as measured by attack number (CAF: 26. 7 ± 1.9; PLA: 27.3 ± 2.1, P = 0.48 or attack time (CAF: 33.8 ± 1.9 s; PLA: 36.6 ± 4.5 s, P = 0.58. Similarly, RPE (CAF: 11.7 ± 0.4 a.u.; PLA: 11.5 ± 0.3 a.u., P = 0.62, HR (CAF: 170 ± 3.5 bpm; PLA: 174.2 bpm, P = 0.12, oxidative (CAF: 109.3 ± 4.5 kJ; PLA: 107.9 kJ, P = 0.61 and ATP-PCr energy contributions (CAF: 45.3 ± 3.4 kJ; PLA: 46.8 ± 3.6 kJ, P = 0.72 during the combat simulation were unaffected. Furthermore

  7. 3-Methyl pyruvate enhances radiosensitivity through increasing mitochondria-derived reactive oxygen species in tumor cell lines

    International Nuclear Information System (INIS)

    Considerable interest has recently been focused on the special characteristics of cancer metabolism, and several drugs designed to modulate cancer metabolism have been tested as potential anticancer agents. To date, however, very few studies have been conducted to investigate the combined effects of anticancer drugs and radiotherapy. In this study, to evaluate the role of mitochondria-derived reactive oxygen species (ROS) in the radiation-induced cell death of tumor cells, we have examined the effect of 3-methyl pyruvate (MP). MP is a membrane-permeable pyruvate derivative that is capable of activating mitochondrial energy metabolism in human lung carcinoma A549 cells and murine squamous carcinoma SCCVII cells. Pretreatment with MP significantly enhanced radiation-induced cell death in both cell lines, and also led to increases in the mitochondrial membrane potential, intracellular adenosine triphosphate content, and mitochondria-derived ROS production following the exposure of the cells to X-rays. In A549 cells, MP-induced radiosensitization was completely abolished by vitamin C. In contrast, it was partially abolished in SCCVII cells. These results therefore suggest that the treatment of the cells with MP induced radiosensitization via the production of excess mitochondria-derived ROS in tumor cells. (author)

  8. Potato chip intake increases ascorbic acid levels and decreases reactive oxygen species in SMP30/GNL knockout mouse tissues.

    Science.gov (United States)

    Kondo, Yoshitaka; Sakuma, Rui; Ichisawa, Megumi; Ishihara, Katsuyuki; Kubo, Misako; Handa, Setsuko; Mugita, Hiroyuki; Maruyama, Naoki; Koga, Hidenori; Ishigami, Akihito

    2014-09-24

    Potato chips (PC) contain abundant amounts of the free radical scavenger ascorbic acid (AA) due to the rapid dehydration of potato tubers (Solanum tuberosum) that occurs during frying. To evaluate the antioxidant activity of PC, this study examined reactive oxygen species (ROS) levels in tissues from SMP30/GNL knockout (KO) mice that cannot synthesize AA and determined AA and ROS levels after the animals were fed 20 and 10% PC diets for 7 weeks. Compared with AA-sufficient mice, AA-depleted SMP30/GNL KO mice showed high ROS levels in tissues. SMP30/GNL KO mice fed a PC diet showed high AA and low ROS levels in the brain, heart, lung, testis, soleus muscle, plantaris muscle, stomach, small intestine, large intestine, eyeball, and epididymal fat compared with AA-depleted mice. The data suggest that PC intake increases AA levels and enhances ROS scavenging activity in tissues of SMP30/GNL KO mice, which are a promising model for evaluating the antioxidant activity of foods. PMID:25180784

  9. PARP-1 inhibition induces a late increase in the level of reactive oxygen species in cells after ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Cieslar-Pobuda, Artur [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, Akademicka 16, 44-100 Gliwice (Poland); Saenko, Yuriy [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, Akademicka 16, 44-100 Gliwice (Poland); Center of Nanotechnology, Ulyanovsk State University, 432700 Ulyanovsk (Russian Federation); Rzeszowska-Wolny, Joanna, E-mail: Joanna.Rzeszowska@polsl.pl [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, Akademicka 16, 44-100 Gliwice (Poland)

    2012-04-01

    Poly(ADP-ribose) polymerase 1 (PARP1), an enzyme activated by DNA strand breaks, synthesizes polymers of poly(ADP-ribose) (PAR) that modify chromatin and other proteins and play a role in DNA repair. Inhibition of PARP1 activity is considered a potentially important strategy in clinical practice, especially to sensitize tumor cells to chemo- and radiotherapy. Here we examined the influence of inhibition of PARP1 on formation of reactive oxygen species (ROS) and on DNA repair in cells exposed to ionizing radiation (IR). K562 (human myelogenous leukaemia) cells were grown and exposed to 4 or 12 Gy of ionizing radiation in presence or absence of the PARP inhibitor NU1025 (100 {mu}M). Intracellular ROS were assayed using the probe 2,7-dichlorofluorescein with detection by flow cytometry and the rejoining of DNA strand breaks were followed by alkaline single cell gel electrophoresis (comet) assays. In untreated cells a significant increase in PAR formation occurred during the first 5 min after IR, followed by a gradual decrease up to 30 min. Addition of a PARP inhibitor arrested the production of PAR almost completely and decreased the rate of rejoining of DNA strand breaks significantly; however, 3 h after irradiation we observed no difference in the amount of DNA strand breaks between PARP inhibitor-treated and untreated cells. Twelve to 48 h after irradiation, an increase of ROS concentration was observed in irradiated cells and ROS levels in PARP inhibitor-treated cells were significantly higher than in cells without inhibitor. Irradiated cells grown in the presence or absence of PARP inhibitor did not differ in the frequencies of apoptotic and necrotic cells or in the activity of caspases at 24, 48 and 72 h after irradiation. Poly(ADP-ribosylation) and inhibition of PARP1 appeared to modulate DNA strand break rejoining and influence the concentration of ROS in irradiated cells.

  10. PARP-1 inhibition induces a late increase in the level of reactive oxygen species in cells after ionizing radiation

    International Nuclear Information System (INIS)

    Poly(ADP-ribose) polymerase 1 (PARP1), an enzyme activated by DNA strand breaks, synthesizes polymers of poly(ADP-ribose) (PAR) that modify chromatin and other proteins and play a role in DNA repair. Inhibition of PARP1 activity is considered a potentially important strategy in clinical practice, especially to sensitize tumor cells to chemo- and radiotherapy. Here we examined the influence of inhibition of PARP1 on formation of reactive oxygen species (ROS) and on DNA repair in cells exposed to ionizing radiation (IR). K562 (human myelogenous leukaemia) cells were grown and exposed to 4 or 12 Gy of ionizing radiation in presence or absence of the PARP inhibitor NU1025 (100 μM). Intracellular ROS were assayed using the probe 2,7-dichlorofluorescein with detection by flow cytometry and the rejoining of DNA strand breaks were followed by alkaline single cell gel electrophoresis (comet) assays. In untreated cells a significant increase in PAR formation occurred during the first 5 min after IR, followed by a gradual decrease up to 30 min. Addition of a PARP inhibitor arrested the production of PAR almost completely and decreased the rate of rejoining of DNA strand breaks significantly; however, 3 h after irradiation we observed no difference in the amount of DNA strand breaks between PARP inhibitor-treated and untreated cells. Twelve to 48 h after irradiation, an increase of ROS concentration was observed in irradiated cells and ROS levels in PARP inhibitor-treated cells were significantly higher than in cells without inhibitor. Irradiated cells grown in the presence or absence of PARP inhibitor did not differ in the frequencies of apoptotic and necrotic cells or in the activity of caspases at 24, 48 and 72 h after irradiation. Poly(ADP-ribosylation) and inhibition of PARP1 appeared to modulate DNA strand break rejoining and influence the concentration of ROS in irradiated cells.

  11. MAPK pathway activation by chronic lead-exposure increases vascular reactivity through oxidative stress/cyclooxygenase-2-dependent pathways

    Energy Technology Data Exchange (ETDEWEB)

    Simões, Maylla Ronacher, E-mail: yllars@hotmail.com [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Aguado, Andrea [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Fiorim, Jonaína; Silveira, Edna Aparecida; Azevedo, Bruna Fernandes; Toscano, Cindy Medice [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Zhenyukh, Olha; Briones, Ana María [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Alonso, María Jesús [Dept. of Biochemistry, Physiology and Molecular Genetics, Universidad Rey Juan Carlos, Alcorcón (Spain); Vassallo, Dalton Valentim [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Health Science Center of Vitória-EMESCAM, Vitória, ES CEP 29045-402 (Brazil); Salaices, Mercedes, E-mail: mercedes.salaices@uam.es [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain)

    2015-03-01

    Chronic exposure to low lead concentration produces hypertension; however, the underlying mechanisms remain unclear. We analyzed the role of oxidative stress, cyclooxygenase-2-dependent pathways and MAPK in the vascular alterations induced by chronic lead exposure. Aortas from lead-treated Wistar rats (1st dose: 10 μg/100 g; subsequent doses: 0.125 μg/100 g, intramuscular, 30 days) and cultured aortic vascular smooth muscle cells (VSMCs) from Sprague Dawley rats stimulated with lead (20 μg/dL) were used. Lead blood levels of treated rats attained 21.7 ± 2.38 μg/dL. Lead exposure increased systolic blood pressure and aortic ring contractile response to phenylephrine, reduced acetylcholine-induced relaxation and did not affect sodium nitroprusside relaxation. Endothelium removal and L-NAME left-shifted the response to phenylephrine more in untreated than in lead-treated rats. Apocynin and indomethacin decreased more the response to phenylephrine in treated than in untreated rats. Aortic protein expression of gp91(phox), Cu/Zn-SOD, Mn-SOD and COX-2 increased after lead exposure. In cultured VSMCs lead 1) increased superoxide anion production, NADPH oxidase activity and gene and/or protein levels of NOX-1, NOX-4, Mn-SOD, EC-SOD and COX-2 and 2) activated ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized superoxide anion production, NADPH oxidase activity and mRNA levels of NOX-1, NOX-4 and COX-2. Blockade of the ERK1/2 and p38 signaling pathways abolished lead-induced NOX-1, NOX-4 and COX-2 expression. Results show that lead activation of the MAPK signaling pathways activates inflammatory proteins such as NADPH oxidase and COX-2, suggesting a reciprocal interplay and contribution to vascular dysfunction as an underlying mechanisms for lead-induced hypertension. - Highlights: • Lead-exposure increases oxidative stress, COX-2 expression and vascular reactivity. • Lead exposure activates MAPK signaling pathway. • ROS and COX-2 activation by

  12. MAPK pathway activation by chronic lead-exposure increases vascular reactivity through oxidative stress/cyclooxygenase-2-dependent pathways

    International Nuclear Information System (INIS)

    Chronic exposure to low lead concentration produces hypertension; however, the underlying mechanisms remain unclear. We analyzed the role of oxidative stress, cyclooxygenase-2-dependent pathways and MAPK in the vascular alterations induced by chronic lead exposure. Aortas from lead-treated Wistar rats (1st dose: 10 μg/100 g; subsequent doses: 0.125 μg/100 g, intramuscular, 30 days) and cultured aortic vascular smooth muscle cells (VSMCs) from Sprague Dawley rats stimulated with lead (20 μg/dL) were used. Lead blood levels of treated rats attained 21.7 ± 2.38 μg/dL. Lead exposure increased systolic blood pressure and aortic ring contractile response to phenylephrine, reduced acetylcholine-induced relaxation and did not affect sodium nitroprusside relaxation. Endothelium removal and L-NAME left-shifted the response to phenylephrine more in untreated than in lead-treated rats. Apocynin and indomethacin decreased more the response to phenylephrine in treated than in untreated rats. Aortic protein expression of gp91(phox), Cu/Zn-SOD, Mn-SOD and COX-2 increased after lead exposure. In cultured VSMCs lead 1) increased superoxide anion production, NADPH oxidase activity and gene and/or protein levels of NOX-1, NOX-4, Mn-SOD, EC-SOD and COX-2 and 2) activated ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized superoxide anion production, NADPH oxidase activity and mRNA levels of NOX-1, NOX-4 and COX-2. Blockade of the ERK1/2 and p38 signaling pathways abolished lead-induced NOX-1, NOX-4 and COX-2 expression. Results show that lead activation of the MAPK signaling pathways activates inflammatory proteins such as NADPH oxidase and COX-2, suggesting a reciprocal interplay and contribution to vascular dysfunction as an underlying mechanisms for lead-induced hypertension. - Highlights: • Lead-exposure increases oxidative stress, COX-2 expression and vascular reactivity. • Lead exposure activates MAPK signaling pathway. • ROS and COX-2 activation by

  13. Solid-state fluorescence property and crystal structure of biphenyl derivatives with carboxyl and n-alkyl groups

    Energy Technology Data Exchange (ETDEWEB)

    Imai, Yoshitane, E-mail: y-imai@apch.kindai.ac.j [Department of Applied Chemistry, Faculty of Science and Engineering, Kinki University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan); Kamon, Kensaku [Department of Applied Chemistry, Faculty of Science and Engineering, Kinki University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan); Tajima, Nobuo [First-Principles Simulation Group, Computational Materials Science Center, NIMS, Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Kinuta, Takafumi [Department of Applied Chemistry, Faculty of Science and Engineering, Kinki University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan); Sato, Tomohiro [JST ERATO-SORST Kuroda Chiromorphology Team, 4-7-6 Komaba, Meguro-ku, Tokyo 153-0041 (Japan); Kuroda, Reiko [JST ERATO-SORST Kuroda Chiromorphology Team, 4-7-6 Komaba, Meguro-ku, Tokyo 153-0041 (Japan); Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Matsubara, Yoshio, E-mail: y-matsu@apch.kindai.ac.j [Department of Applied Chemistry, Faculty of Science and Engineering, Kinki University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan)

    2010-06-15

    By introducing carboxyl and n-alkyl groups into a biphenyl molecule, we can increase the photoluminescence quantum yields of biphenyl derivatives in the solid state. The solid-state fluorescence maxima (lambda{sub em}) of 4-biphenylcarboxylic acid derivatives change according to the n-alkyl group introduced.

  14. Increased platelet expression of FcGammaRIIa and its potential impact on platelet reactivity in patients with end stage renal disease

    Directory of Open Access Journals (Sweden)

    Sobel Burton E

    2007-06-01

    Full Text Available Abstract Background Increased platelet reactivity has been implicated in cardiovascular disease – the major cause of death in patients with end stage renal disease (ESRD. FcGammaRIIA is a component of glycoprotein VI and Ib-IX-V that mediate activation of platelets by collagen and von Willebrand factor. To determine whether expression of FcGammaRIIA impacts platelet reactivity we quantified its expression and platelet reactivity in 33 patients with ESRD who were undergoing hemodialysis. Methods Blood samples were obtained from patients immediately before hemodialysis and before administration of heparin. Platelet expression of FcGammaRIIA and the activation of platelets in response to low concentrations of convulxin (1 ng/ml, selected to mimic effects of collagen, thrombin (1 nM, adenosine diphosphate (ADP, 0.2 uM, or platelet activating factor (PAF, 1 nM were determined with the use of flow cytometry in samples of whole blood anticoagulated with corn trypsin inhibitor (a specific inhibitor of Factor XIIa. Results Patients were stratified with respect to the median expression of FcGammaRIIA. Patients with high platelet expression of FcGammaRIIA exhibited 3-fold greater platelet reactivity compared with that in those with low expression in response to convulxin (p Conclusion Increased platelet reactivity in response to low concentrations of diverse agonists is associated with high expression of FcGammaRIIA and may contribute to an increased risk of thrombosis in patients with ESRD.

  15. C-reactive protein is increased in schizophrenia but is not altered by antipsychotics: meta-analysis and implications.

    Science.gov (United States)

    Fernandes, B S; Steiner, J; Bernstein, H-G; Dodd, S; Pasco, J A; Dean, O M; Nardin, P; Gonçalves, C-A; Berk, M

    2016-04-01

    The inflammatory hypothesis of schizophrenia (SZ) posits that inflammatory processes and neural-immune interactions are involved in its pathogenesis, and may underpin some of its neurobiological correlates. SZ is the psychiatric disorder causing the most severe burden of illness, not just owing to its psychiatric impairment, but also owing to its significant medical comorbidity. C-reactive protein (CRP) is a commonly used biomarker of systemic inflammation worldwide. There are some conflicting results regarding the behaviour of CRP in SZ. The aims of this study were to verify whether peripheral CRP levels are indeed increased in SZ, whether different classes of antipsychotics divergently modulate CRP levels and whether its levels are correlated with positive and negative symptomatology. With that in mind, we performed a meta-analysis of all cross-sectional studies of serum and plasma CRP levels in SZ compared to healthy subjects. In addition, we evaluated longitudinal studies on CRP levels before and after antipsychotic use. Our meta-analyses of CRP in SZ included a total of 26 cross-sectional or longitudinal studies comprising 85 000 participants. CRP levels were moderately increased in persons with SZ regardless of the use of antipsychotics and did not change between the first episode of psychosis and with progression of SZ (g=0.66, 95% confidence interval (95% CI) 0.43 to 0.88, Pbody mass index. Conversely, higher age correlated with a smaller difference in CRP levels between persons with SZ and controls. Furthermore, CRP levels did not increase after initiation of antipsychotic medication notwithstanding whether these were typical or atypical antipsychotics (g=0.01, 95% CI -0.20 to 0.22, P=0.803, 8 within-group comparisons, n=713). In summary, our study provides further evidence of the inflammatory hypothesis of SZ. Whether there is a causal relationship between higher CRP levels and the development of SZ and aggravation of psychotic symptoms, or whether they

  16. Popcorn worker's lung: In vitro exposure to diacetyl, an ingredient in microwave popcorn butter flavoring, increases reactivity to methacholine

    International Nuclear Information System (INIS)

    Workers who inhale microwave popcorn butter flavorings experience decrements in lung function and can develop clinical bronchiolitis obliterans, i.e., 'popcorn worker's lung' (Kreiss, K., Gomaa, A., Kullman, G., Fedan, K., Simoes, E.J., Enright, P.L., 2002. Clinical bronchiolitis obliterans in workers at a microwave-popcorn plant. N. Engl. J. Med. 347, 330-338.). In a rat inhalation model, vapors of an artificial butter flavoring damaged the epithelium of the upper and lower airways (Hubbs, A.F., Battelli, L.A., Goldsmith, W.T., Porter, D.W., Frazer, D., Friend, S., Schwegler-Berry, D., Mercer, R.R., Reynolds, J.S., Grote, A., Castranova, V., Kullman, G., Fedan, J.S., Dowdy, J., Jones, W.G., 2002. Necrosis of nasal and airway epithelium in rats inhaling vapors of artificial butter flavoring. Toxicol. Appl. Pharmacol. 185, 128-135.). Diacetyl, a butter flavoring component, is a major volatile ketone in the popcorn-processing workplace. We investigated the effects of diacetyl on epithelium of guinea pig isolated airway preparations and the effects of diacetyl in vitro on reactivity to bronchoactive agents. In the isolated, perfused trachea preparation, diacetyl added to the intraluminal (mucosal) bath elicited responses that began with contraction (threshold ca. 3 mM) and ended with relaxation. After a 4-h incubation with intraluminal diacetyl (3 mM), contractions to extraluminal (serosal) methacholine (MCh) were slightly increased; however, sensitivity to intraluminally (mucosally) applied MCh was increased by 10-fold. Relaxation responses of MCh (3 x 10-7 M)-contracted tracheas to extraluminally applied terbutaline and intraluminally applied 120 mM KCl, to evoke epithelium-derived relaxing factor release, were unaffected by diacetyl. Exposure of the tracheal epithelium in Ussing chambers to diacetyl decreased transepithelial potential difference and resistance. These findings suggest that diacetyl exposure compromised epithelial barrier function, leading to

  17. A herpes simplex virus type 1 latency-associated transcript mutant with increased virulence and reduced spontaneous reactivation

    Science.gov (United States)

    The herpes simplex virus type 1 (HSV-1) latency-associated transcript (LAT) gene is essential for efficient spontaneous reactivation of HSV-1 from latency. We previously reported that insertion of the LAT promoter and just the first 1.5 kb of the 8.3 LAT gene into an ectopic location in the virus re...

  18. Increased dietary protein attenuates C-reactive protein and creatine kinase responses to exercise-induced energy deficit

    Science.gov (United States)

    We determined if dietary protein (P) modulates responses of C-reactive protein (CRP) and creatine kinase (CK), biomarkers of inflammation and muscle damage, during exercise-induced energy deficit (DEF). Thirteen healthy men (22 +/- 1 y, VO2peak 60 +/- 2 ml.kg-1.min-1) balanced energy expenditure (EE...

  19. Increased cerebrovascular pCO2 reactivity in migraine with aura--a transcranial Doppler study during hyperventilation

    DEFF Research Database (Denmark)

    Thomsen, L L; Iversen, Helle Klingenberg; Olesen, J

    1995-01-01

    cerebral artery was measured with transcranial Doppler. In each subject a pCO2 reactivity index (RI) was calculated as (delta Vmean/baseline Vmean)/delta pCO2. Interictally, patients with migraine with aura showed higher RI (p < 0.05 ANOVA and multiple range test) than controls, whereas migraineurs without...

  20. Optimizing shape uniformity and increasing structure heights of deep reactive ion etched silicon x-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik; Wright, Jonathan; Simons, Hugh;

    2015-01-01

    Line-focusing compound silicon x-ray lenses with structure heights exceeding 300 μm were fabricated using deep reactive ion etching. To ensure profile uniformity over the full height, a new strategy was developed in which the perimeter of the structures was defined by trenches of constant width...

  1. Low levels of vitamin C in dialysis patients is associated with decreased prealbumin and increased C-reactive protein

    Directory of Open Access Journals (Sweden)

    Cheng Xuyang

    2011-05-01

    Full Text Available Abstract Background Subclinical inflammation is a common phenomenon in patients on either continuous ambulatory peritoneal dialysis (CAPD or maintenance hemodialysis (MHD. We hypothesized that vitamin C had anti-inflammation effect because of its electron offering ability. The current study was designed to test the relationship of plasma vitamin C level and some inflammatory markers. Methods In this cross-sectional study, 284 dialysis patients were recruited, including 117 MHD and 167 CAPD patients. The demographics were recorded. Plasma vitamin C was measured by high-performance liquid chromatography. And we also measured body mass index (BMI, calculated as weight/height2, Kt/V, serum albumin, serum prealbumin, high-sensitivity C-reactive protein (hsCRP, ferritin, hemoglobin. The relationships between vitamin C and albumin, pre-albumin and hsCRP levels were tested by Spearman correlation analysis and multiple regression analysis. Patients were classified into three subgroups by vitamin C level according to previous recommendation 12 in MHD and CAPD patients respectively: group A: 4 ug/ml (> 22.8 umol/l, normal and above. Results Patients showed a widely distribution of plasma vitamin C levels in the total 284 dialysis patients. Vitamin C deficiency ( 14 ug/ml. The similar proportion of different vitamin C levels was found in both MHD and CAPD groups. Plasma vitamin C level was inversely associated with hsCRP concentration (Spearman r = -0.201, P = 0.001 and positively associated with prealbumin (Spearman r = 0.268, P 10hsCRP (P = 0.048 and positively with prealbumin levels (P = 0.002 adjusted for gender, age, diabetes, modality of dialysis and some other confounding effects. Conclusions The investigation indicates that vitamin C deficiency is common in both MHD patients and CAPD patients. Plasma vitamin C level is positively associated with serum prealbumin level and negatively associated with hsCRP level in both groups. Vitamin C deficiency

  2. Oxidation of Fatty Acids Is the Source of Increased Mitochondrial Reactive Oxygen Species Production in Kidney Cortical Tubules in Early Diabetes

    OpenAIRE

    Rosca, Mariana G.; Vazquez, Edwin J.; Chen, Qun; Kerner, Janos; Kern, Timothy S.; Hoppel, Charles L.

    2012-01-01

    Mitochondrial reactive oxygen species (ROS) cause kidney damage in diabetes. We investigated the source and site of ROS production by kidney cortical tubule mitochondria in streptozotocin-induced type 1 diabetes in rats. In diabetic mitochondria, the increased amounts and activities of selective fatty acid oxidation enzymes is associated with increased oxidative phosphorylation and net ROS production with fatty acid substrates (by 40% and 30%, respectively), whereas pyruvate oxidation is decr...

  3. Reactive and proactive control adjustments under increased depressive symptoms : insights from the classic and emotional-face Stroop task

    OpenAIRE

    Saunders, Blair; Jentzsch, Ines

    2014-01-01

    The current research investigated differences in reactive and proactive cognitive control as a function of depressive symptomatology. Three participant groups with varying symptom levels (Beck Depression Inventory–II, BDI–II score) completed both the classic and an emotional-face Stroop task separately under speed and accuracy instructions. All groups made equivalent speed–accuracy trade-offs independent of task, suggesting that proactive adjustments are unaffected by depressive symptoms. Add...

  4. Triglyceride-rich lipoprotein lipolysis increases aggregation of endothelial cell membrane microdomains and produces reactive oxygen species

    OpenAIRE

    Wang, Limin; Sapuri-Butti, Annapoorna R.; Aung, Hnin Hnin; Parikh, Atul N.; Rutledge, John C

    2008-01-01

    Triglyceride-rich lipoprotein (TGRL) lipolysis may provide a proinflammatory stimulus to endothelium. Detergent-resistant plasma membrane microdomains (lipid rafts) have a number of functions in endothelial cell inflammation. The mechanisms of TGRL lipolysis-induced endothelial cell injury were investigated by examining endothelial cell lipid rafts and production of reactive oxygen species (ROS). Lipid raft microdomains in human aortic endothelial cells were visualized by confocal microscopy ...

  5. Self-reactive CD4+ T cells and B cells in the blood in health and autoimmune disease: increased frequency of thyroglobulin-reactive cells in Graves' disease

    DEFF Research Database (Denmark)

    Nielsen, Claus H; Moeller, Ane Christine; Hegedüs, Laszlo;

    2006-01-01

    with autoimmune thyroiditis. In Hashimoto's thyroiditis, B cells bound increased amounts of thyroglobulin in a complement- and autoantibody-dependent manner, and the thyroglobulin-elicited proliferation of CD4(+) T cells and B cells was complement dependent. Increased proportions of Tg-responsive CD4......(+) T cells and B cells were found in patients with Graves' disease. Notably, both patient groups and healthy controls exhibited higher proliferative responses to thyroglobulin than to a foreign recall antigen, tetanus toxoid. Our results suggest that self-tolerance can be broken by exposure of...... circulating lymphocytes to high local concentrations of self-antigen, and that complement plays a role in the maintenance of autoimmune processes, at least in Hashimoto's thyroiditis....

  6. Construction of a Bioluminescent Reporter Strain To Detect Polychlorinated Biphenyls

    OpenAIRE

    Layton, A C; Muccini, M.; Ghosh, M. M.; Sayler, G. S.

    1998-01-01

    A bioluminescent reporter strain, Ralstonia eutropha ENV307(pUTK60), was constructed for the detection of polychlorinated biphenyls by inserting the biphenyl promoter upstream of the bioluminescence genes. In the presence of a nonionic surfactant, which enhances the solubility of chlorinated biphenyls, bioluminescence was induced three- to fourfold over background by biphenyl, monochlorinated biphenyls, and Aroclor 1242. The minimum detection limits for these compounds ranged from 0.15 mg/lit...

  7. Remediation of soils contaminated with polychlorinated biphenyls by microwave-irradiated manganese dioxide

    International Nuclear Information System (INIS)

    The removal of polychlorinated biphenyls (PCBs) using microwave-irradiated manganese dioxide (MnO2) in PCB-contaminated soils under different conditions is investigated. The removal of PCB77 in two actual soil samples exhibits strong pH-dependent behavior, and the removal efficiency is higher in acidic soil (Ali-Perudic Ferrosols) than that in neutral soil (Udic Argosols). The removal kinetics of PCB77 using microwave-irradiated MnO2 under different experimental conditions fits a pseudo-first-order kinetic model well. Both the removal efficiency and the kinetic constant (k) values of PCB77 in Ali-Perudic Ferrosols considerably increase, although in a nonlinear fashion, as the initial amount of MnO2 is increased, as the treated soil mass is increased, and as the microwave power is increased. The reactivity of three PCBs (PCB28, PCB77, and PCB118) did not present as a function of the degree of chlorination in the reaction with microwave-irradiated MnO2. The pronounced removal of three PCBs in contaminated soil (all above 95%) indicates that MnO2 in combination with microwave irradiation is promising for technological applications that seek to remediate sites critically polluted with PCBs.

  8. Deletion of GSTA4-4 results in increased mitochondrial post-translational modification of proteins by reactive aldehydes following chronic ethanol consumption in mice.

    Science.gov (United States)

    Shearn, Colin T; Fritz, Kristofer S; Shearn, Alisabeth H; Saba, Laura M; Mercer, Kelly E; Engi, Bridgette; Galligan, James J; Zimniak, Piotr; Orlicky, David J; Ronis, Martin J; Petersen, Dennis R

    2016-04-01

    Chronic alcohol consumption induces hepatic oxidative stress resulting in production of highly reactive electrophilic α/β-unsaturated aldehydes that have the potential to modify proteins. A primary mechanism of reactive aldehyde detoxification by hepatocytes is through GSTA4-driven enzymatic conjugation with GSH. Given reports that oxidative stress initiates GSTA4 translocation to the mitochondria, we hypothesized that increased hepatocellular damage in ethanol (EtOH)-fed GSTA4(-/-) mice is due to enhanced mitochondrial protein modification by reactive aldehydes. Chronic ingestion of EtOH increased hepatic protein carbonylation in GSTA4(-/-) mice as evidenced by increased 4-HNE and MDA immunostaining in the hepatic periportal region. Using mass spectrometric analysis of biotin hydrazide conjugated carbonylated proteins, a total of 829 proteins were identified in microsomal, cytosolic and mitochondrial fractions. Of these, 417 were novel to EtOH models. Focusing on mitochondrial fractions, 1.61-fold more carbonylated proteins were identified in EtOH-fed GSTA4(-)(/-) mice compared to their respective WT mice ingesting EtOH. Bioinformatic KEGG pathway analysis of carbonylated proteins from the mitochondrial fractions revealed an increased propensity for modification of proteins regulating oxidative phosphorylation, glucose, fatty acid, glutathione and amino acid metabolic processes in GSTA4(-/-) mice. Additional analysis revealed sites of reactive aldehyde protein modification on 26 novel peptides/proteins isolated from either SV/GSTA4(-/-) PF or EtOH fed mice. Among the peptides/proteins identified, ACSL, ACOX2, MTP, and THIKB contribute to regulation of fatty acid metabolism and ARG1, ARLY, and OAT, which regulate nitrogen and ammonia metabolism having direct relevance to ethanol-induced liver injury. These data define a role for GSTA4-4 in buffering hepatic oxidative stress associated with chronic alcohol consumption and that this GST isoform plays an important

  9. Deletion of GSTA4-4 results in increased mitochondrial post-translational modification of proteins by reactive aldehydes following chronic ethanol consumption in mice

    Directory of Open Access Journals (Sweden)

    Colin T. Shearn

    2016-04-01

    Full Text Available Chronic alcohol consumption induces hepatic oxidative stress resulting in production of highly reactive electrophilic α/β-unsaturated aldehydes that have the potential to modify proteins. A primary mechanism of reactive aldehyde detoxification by hepatocytes is through GSTA4-driven enzymatic conjugation with GSH. Given reports that oxidative stress initiates GSTA4 translocation to the mitochondria, we hypothesized that increased hepatocellular damage in ethanol (EtOH-fed GSTA4−/− mice is due to enhanced mitochondrial protein modification by reactive aldehydes. Chronic ingestion of EtOH increased hepatic protein carbonylation in GSTA4−/− mice as evidenced by increased 4-HNE and MDA immunostaining in the hepatic periportal region. Using mass spectrometric analysis of biotin hydrazide conjugated carbonylated proteins, a total of 829 proteins were identified in microsomal, cytosolic and mitochondrial fractions. Of these, 417 were novel to EtOH models. Focusing on mitochondrial fractions, 1.61-fold more carbonylated proteins were identified in EtOH-fed GSTA4−/− mice compared to their respective WT mice ingesting EtOH. Bioinformatic KEGG pathway analysis of carbonylated proteins from the mitochondrial fractions revealed an increased propensity for modification of proteins regulating oxidative phosphorylation, glucose, fatty acid, glutathione and amino acid metabolic processes in GSTA4−/− mice. Additional analysis revealed sites of reactive aldehyde protein modification on 26 novel peptides/proteins isolated from either SV/GSTA4−/− PF or EtOH fed mice. Among the peptides/proteins identified, ACSL, ACOX2, MTP, and THIKB contribute to regulation of fatty acid metabolism and ARG1, ARLY, and OAT, which regulate nitrogen and ammonia metabolism having direct relevance to ethanol-induced liver injury. These data define a role for GSTA4-4 in buffering hepatic oxidative stress associated with chronic alcohol consumption and that this GST

  10. Increased peripheral T cell reactivity to microbial antigens and collagen type II in rheumatoid arthritis after treatment with soluble TNFα receptors

    OpenAIRE

    Berg, L; Lampa, J; Rogberg, S; van Vollenhoven, R; Klareskog, L

    2001-01-01

    OBJECTIVE—Peripheral T cells from patients with rheumatoid arthritis (RA) are hyporesponsive when stimulated with antigen or mitogen in vitro, possibly owing to increased production of proinflammatory cytokines such as tumour necrosis factor α (TNFα). This study sought to find out if and how RA T cell reactivity is affected during treatment with etanercept (Enbrel), a soluble TNFα receptor.
METHODS—Heparinised blood was collected from patients with RA at baseline, after four and eight weeks o...

  11. Reducing Cytoplasmic Polyamine Oxidase Activity in Arabidopsis Increases Salt and Drought Tolerance by Reducing Reactive Oxygen Species Production and Increasing Defense Gene Expression.

    Science.gov (United States)

    Sagor, G H M; Zhang, Siyuan; Kojima, Seiji; Simm, Stefan; Berberich, Thomas; Kusano, Tomonobu

    2016-01-01

    The link between polyamine oxidases (PAOs), which function in polyamine catabolism, and stress responses remains elusive. Here, we address this issue using Arabidopsis pao mutants in which the expression of the five PAO genes is knocked-out or knocked-down. As the five single pao mutants and wild type (WT) showed similar response to salt stress, we tried to generate the mutants that have either the cytoplasmic PAO pathway (pao1 pao5) or the peroxisomal PAO pathway (pao2 pao3 pao4) silenced. However, the latter triple mutant was not obtained. Thus, in this study, we used two double mutants, pao1 pao5 and pao2 pao4. Of interest, pao1 pao5 mutant was NaCl- and drought-tolerant, whereas pao2 pao4 showed similar sensitivity to those stresses as WT. To reveal the underlying mechanism of salt tolerance, further analyses were performed. Na uptake of the mutant (pao1 pao5) decreased to 75% of WT. PAO activity of the mutant was reduced to 62% of WT. The content of reactive oxygen species (ROS) such as hydrogen peroxide, a reaction product of PAO action, and superoxide anion in the mutant became 81 and 72% of the levels in WT upon salt treatment. The mutant contained 2.8-fold higher thermospermine compared to WT. Moreover, the mutant induced the genes of salt overly sensitive-, abscisic acid (ABA)-dependent- and ABA-independent- pathways more strongly than WT upon salt treatment. The results suggest that the Arabidopsis plant silencing cytoplasmic PAOs shows salinity tolerance by reducing ROS production and strongly inducing subsets of stress-responsive genes under stress conditions. PMID:26973665

  12. Bioelectrochemical Immunoassay of Polychlorinated Biphenyl

    International Nuclear Information System (INIS)

    A simple, rapid, and highly sensitive bioelectrochemical immunoassay method based on magnetic beads (MBs) and disposable screen-printed electrodes (SPE) has been developed to detect polychlorinated biphenyls (PCBs). The principle of this bioassay is based on a direct competitive enzyme-linked immunosorbent assay using PCB-antibody-coated MBs and horseradish peroxidase (HRP)-labeled PCB (HRP-PCB). A magnetic process platform was used to mix and shake the samples during the immunoreactions and to separate free and unbound reagents after the liquid-phase competitive immunoreactions among PCB-antibody-coated MBs, PCB analyte, and HRP-PCB. After a complete immunoassay, the HRP tracers attached to MBs were transferred to a substrate solution containing o-aminophenol and hydrogen peroxide for electrochemical detection. The different parameters, including the amount of HRP-PCB conjugates, immunoreaction time, and the concentration of substrate that governs the analytical performance of the immunoassay have been studied in detail and optimized. The detection limit of 5 pg mL-1 was obtained under optimum experimental conditions. The performance of this bioelectrochemical immunoassay was successfully evaluated with untreated river water spiked with PCBs, and the results were validated by commercial PCB enzyme-linked immunosorbent assay kit, indicating that this convenient and sensitive technique offers great promise for decentralized environmental application and trace PCBs monitoring

  13. Increased serum levels of C-reactive protein and matrix metalloproteinase-9 in obstructive sleep apnea syndrome

    Institute of Scientific and Technical Information of China (English)

    YE Jin; LIU Hui; LI Yuan; LIU Xian; ZHU Jie-ming

    2007-01-01

    Background Obstructive sleep apnea syndrome (OSAS), characterized by intermittent hypoxia/reoxygenation (IHR),has been identified as an independent risk factor for cardiovascular diseases (CVD). The CVD biomarkers associated with OSAS have not been thoroughly investigated.Methods Fifty-one men with OSAS recently diagnosed by polysomnography were classified into two groups according to the severity of apnea: moderate to severe OSAS group (n= 28) and mild OSAS group (n= 23). Twenty-five obese men,of comparable age and body mass index (BMI), without OSAS were chosen as control subjects. Serum metabolic variables, C-reactive protein (CRP) and matrix metalloproteinase-9 (MMP-9) were measured. Spearman correlation and regression analysis were performed.Results Serum concentrations of CRP and MMP-9 were significantly higher in 51 OSAS patients than in 25 control subjects. Levels of CRP and MMP-9 were significantly higher in patients with moderate to severe OSAS than in patients with mild OSAS or in obese control subjects. A positive correlation was found between levels of CRP and MMP-9 in OSAS patients. Regression analysis showed that after adjusting for age and BMI, apnea/hypopnea index (AHI) significantly correlated with serum concentrations of CRP and MMP-9 in patients with OSAS.Conclusions AHI, mirroring the frequency of IHR, was a predictor of enhanced circulating CVD biomarkers MMP-9 and CRP. Our data support the theory that IHR contributes to the upregulation of the inflammatory factors in OSAS patients.

  14. Optimizing shape uniformity and increasing structure heights of deep reactive ion etched silicon x-ray lenses

    International Nuclear Information System (INIS)

    Line-focusing compound silicon x-ray lenses with structure heights exceeding 300 μm were fabricated using deep reactive ion etching. To ensure profile uniformity over the full height, a new strategy was developed in which the perimeter of the structures was defined by trenches of constant width. The remaining sacrificial material inside the lens cavities was removed by etching through the silicon wafer. Since the wafers become fragile after through-etching, they were then adhesively bonded to a carrier wafer. Individual chips were separated using laser micro machining and the 3D shape of fabricated lenses was thoroughly characterized by a variety of means. Optical testing using synchrotron radiation with a photon energy of 56 keV yielded a 300 μm wide beam with a waist of 980 nm (full width at half maximum) at a focal length of 1.3 m. Optical aberrations are discussed in the context of the shape analysis, where a slight bowing of the lens sidewalls and an insufficiently uniform apex region are identified as resolution-limiting factors. Despite these, the proposed fabrication route proved a viable approach for producing x-ray lenses with large structure heights and provides the means to improve the resolution and capabilities of modern x-ray techniques such as x-ray microscopy and 3D x-ray diffraction. (paper)

  15. Optimizing shape uniformity and increasing structure heights of deep reactive ion etched silicon x-ray lenses

    Science.gov (United States)

    Stöhr, Frederik; Wright, Jonathan; Simons, Hugh; Michael-Lindhard, Jonas; Hübner, Jörg; Jensen, Flemming; Hansen, Ole; Poulsen, Henning Friis

    2015-12-01

    Line-focusing compound silicon x-ray lenses with structure heights exceeding 300 μm were fabricated using deep reactive ion etching. To ensure profile uniformity over the full height, a new strategy was developed in which the perimeter of the structures was defined by trenches of constant width. The remaining sacrificial material inside the lens cavities was removed by etching through the silicon wafer. Since the wafers become fragile after through-etching, they were then adhesively bonded to a carrier wafer. Individual chips were separated using laser micro machining and the 3D shape of fabricated lenses was thoroughly characterized by a variety of means. Optical testing using synchrotron radiation with a photon energy of 56 keV yielded a 300 μm wide beam with a waist of 980 nm (full width at half maximum) at a focal length of 1.3 m. Optical aberrations are discussed in the context of the shape analysis, where a slight bowing of the lens sidewalls and an insufficiently uniform apex region are identified as resolution-limiting factors. Despite these, the proposed fabrication route proved a viable approach for producing x-ray lenses with large structure heights and provides the means to improve the resolution and capabilities of modern x-ray techniques such as x-ray microscopy and 3D x-ray diffraction.

  16. Consolidated PCBs [polychlorinated biphenyls] improves waste control

    International Nuclear Information System (INIS)

    Consolidation of polychlorinated biphenyl (PCB) wastes is recommended for improving ownership control of wastes, eliminating PCB storage sites, and increasing cost-effectiveness of waste management. In Ontario, sites receiving the waste must be owned by the waste generator and registered as a PCB site. All PCBs must be removed from a site with no contaminated materials or wastes left behind, which requires a thorough site assessment to identify wastes prior to removal, a sampling and analytical scheme if necessary, and an approved plan for site cleanup. If large volumes of PCB-contaminated oil are involved, it may be cost-effective to put oil from several sites into bulk tanks and thus avoid the need to handle and decontaminate a large number of drums. With low volumes of oil, it may be possible to move the waste to another site where mobile PCB destruction is taking place. It also may be possible to get approval to blend high-level PCB liquids with mineral oil to reduce the PCB concentration to a level where chemical decontamination is allowed. For large volumes of high-level PCB wastes, consolidation will be necessary simply because of the high costs of mobilizing an incinerator and the requirement for public hearings for each incineration project. To make such a project cost-effective, PCB wastes will have to be concentrated from a large geographic area. 1 fig

  17. Murine cytomegalovirus immediate-early 1 gene expression correlates with increased GVHD after allogeneic hematopoietic cell transplantation in recipients reactivating from latent infection.

    Directory of Open Access Journals (Sweden)

    Senthilnathan Palaniyandi

    Full Text Available The success of allogeneic (allo hematopoietic cell transplantation (HCT is limited by its treatment related complications, mostly graft versus host disease (GVHD and fungal and viral infections. CMV reactivation after HCT has been associated with increased morbidity and mortality, and a causal relation between GVHD, immunosuppressive therapy and vice versa has been postulated. Using a low GVHD severity murine HCT model, we assessed the role of MCMV reactivation and GVHD development. BALB/c mice were infected with either murine CMV (MCMV or mock and monitored for 25 weeks to establish latency, followed by sublethal irradiation conditioning and infusion of bone marrow plus splenocytes from either syngeneic (syn BALB/c or allo B10.D2 donors. Engraftment of allo donor cells was confirmed by PCR for D2Mit265 gene product size. Day+100 mortality and overall GVHD severity in allo MCMV pre-infected recipients was higher than in allo mock controls. Pathologic changes of lung and liver GVHD in immediate-early gene 1 (IE1 positive recipients were significantly increased compared to mock controls, and were only slightly increased in IE1 negative. No significant gut injury was seen in any group. Aggravated lung injury in IE1 positive recipients correlated with higher BAL cell counts both for total cells and for CD4+ T cells when compared with mock controls, and also with protein expression of lung IFN-gamma and liver TNF. No evidence for CMV specific morphologic changes was seen on histopathology in any organ of IE1 positive recipients, suggesting that CMV reactivation is related to increased GVHD severity but does not require active CMV disease, strengthening the concept of a reciprocal relationship between CMV and GVHD.

  18. Incidence of thyroid disease following exposure to polybrominated biphenyls and polychlorinated biphenyls, Michigan, 1974-2006.

    Science.gov (United States)

    Yard, Ellen E; Terrell, Metrecia L; Hunt, Danielle Rentz; Cameron, Lorraine L; Small, Chanley M; McGeehin, Michael A; Marcus, Michele

    2011-08-01

    Thyroid hormones, which influence body metabolism and development, could be affected by persistent organic pollutants. We sought to examine the relationship between polybrominated biphenyls (PBBs) and polychlorinated biphenyls (PCBs) and thyroid disease. We employed incidence density sampling to perform a nested case control analysis of the Michigan Long-Term PBB Cohort. Cohort members (n=3333) were exposed to PBBs through contaminated cattle feed in 1973-1974 and to PCBs through daily life. Those with detectable serum PBB and PCB concentrations at enrollment were categorized into tertiles of PBB and PCB exposure. Case-patients were cohort members answering "Yes" to "Has a healthcare provider ever told you that you had a thyroid problem?" during follow-up interviews; control-patients were cohort members answering "No". We used odds ratios (OR) with 95% confidence intervals (CI) to compare odds of thyroid disease by PBB and PCB exposure and by various risk factors. Total cumulative thyroid disease incidence after 33 years was 13.9% among women and 2.6% among men. After adjusting for body mass index, we found no statistically significant differences in odds of any type of thyroid disease among women or men with elevated PBB or PCB exposure. Compared to control-patients, women with thyroid disease had increased odds of being overweight/obese (OR=2.82, 95% CI: 1.94-4.11) and developing infertility (OR=1.71, 95% CI: 1.08-2.69), diabetes (OR=1.61, 95% CI: 1.04-2.51), or arthritis (OR=1.71, 95% CI: 1.18-2.50) during follow-up. Additional research should explore potential associations between PBBs/PCBs and thyroid disease among children exposed in utero. PMID:21737118

  19. Monomeric C-reactive protein and Notch-3 co-operatively increase angiogenesis through PI3K signalling pathway.

    Science.gov (United States)

    Boras, Emhamed; Slevin, Mark; Alexander, M Yvonne; Aljohi, Ali; Gilmore, William; Ashworth, Jason; Krupinski, Jerzy; Potempa, Lawrence A; Al Abdulkareem, Ibrahim; Elobeid, Adila; Matou-Nasri, Sabine

    2014-10-01

    C-reactive protein (CRP) is the most acute-phase reactant serum protein of inflammation and a strong predictor of cardiovascular disease. Its expression is associated with atherosclerotic plaque instability and the formation of immature micro-vessels. We have previously shown that CRP upregulates endothelial-derived Notch-3, a key receptor involved in vascular development, remodelling and maturation. In this study, we investigated the links between the bioactive monomeric CRP (mCRP) and Notch-3 signalling in angiogenesis. We used in vitro (cell counting, wound-healing and tubulogenesis assays) and in vivo (chorioallantoic membrane) angiogenic assays and Western blotting to study the angiogenic signalling pathways induced by mCRP and Notch-3 activator chimera protein (Notch-3/Fc). Our results showed an additive effect on angiogenesis of mCRP stimulatory effect combined with Notch-3/Fc promoting bovine aortic endothelial cell (BAEC) proliferation, migration, tube formation in Matrigel(TM) with up-regulation of phospho-Akt expression. The pharmacological blockade of PI3K/Akt survival pathway by LY294002 fully inhibited in vitro and in vivo angiogenesis induced by mCRP/Notch-3/Fc combination while blocking Notch signalling by gamma-secretase inhibitor (DAPT) partially inhibited mCRP/Notch-3/Fc-induced angiogenesis. Using a BAEC vascular smooth muscle cell co-culture sprouting angiogenesis assay and transmission electron microscopy, we showed that activation of both mCRP and Notch-3 signalling induced the formation of thicker sprouts which were shown later by Western blotting to be associated with an up-regulation of N-cadherin expression and a down-regulation of VE-cadherin expression. Thus, mCRP combined with Notch-3 activator promote angiogenesis through the PI3K/Akt pathway and their therapeutic combination has potential to promote and stabilize vessel formation whilst reducing the risk of haemorrhage from unstable plaques. PMID:24972386

  20. Microbial transformation and degradation of polychlorinated biphenyls

    International Nuclear Information System (INIS)

    This paper reviews the potential of microorganisms to transform polychlorinated biphenyls (PCBs). In anaerobic environments, higher chlorinated biphenyls can undergo reductive dehalogenation. Meta- and para-chlorines in PCB congeners are more susceptible to dechlorination than ortho-chlorines. Anaerobes catalyzing PCB dechlorination have not been isolated in pure culture but there is strong evidence from enrichment cultures that some Dehalococcoides spp. and other microorganisms within the Chloroflexi phylum can grow by linking the oxidation of H2 to the reductive dechlorination of PCBs. Lower chlorinated biphenyls can be co-metabolized aerobically. Some aerobes can also grow by utilizing PCB congeners containing only one or two chlorines as sole carbon/energy source. An example is the growth of Burkholderia cepacia by transformation of 4-chlorobiphenyl to chlorobenzoates. The latter compounds are susceptible to aerobic mineralization. Higher chlorinated biphenyls therefore are potentially fully biodegradable in a sequence of reductive dechlorination followed by aerobic mineralization of the lower chlorinated products. - Higher chlorinated biphenyls are potentially fully biodegradable in a sequence of anaerobic reductive dechlorination followed by aerobic mineralization of the lower chlorinated products

  1. Influence of polychlorinated biphenyls on the growth of chicken embryos

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, Yasuhiko; Hatano, Akira [Chub Women`s College, Gifu-ken (Japan)

    1994-12-31

    Incubation of chicken embryos with either 0.01 or 0.03 ppm polychlorinated biphenyls (PCBs) for 12, 15, or 18 d resulted in a significant decrease in liver and body weight associated with enhanced mortality. Teratological examination revealed an increased frequency of malformations including hydrops, eventration, wry neck, and brevicollis. PCB exposure was also found to produce histologic damage to liver and cutaneous tissue. Our data demonstrate that exposure of chicks to PCBs during development results in a retardation of growth, an increased incidence of malformations, and histopathologic damage. 9 refs., 2 figs., 4 tabs.

  2. Directed evolution of the suicide protein O⁶-alkylguanine-DNA alkyltransferase for increased reactivity results in an alkylated protein with exceptional stability

    OpenAIRE

    Mollwitz, Birgit; Brunk, Elizabeth; Schmitt, Simone; Pojer, Florence; Bannwarth, Michael; Schiltz, Marc; Rothlisberger, Ursula; Johnsson, Kai

    2012-01-01

    Here we present a biophysical, structural, and computational analysis of the directed evolution of the human DNA repair protein O(6)-alkylguanine-DNA alkyltransferase (hAGT) into SNAP-tag, a self-labeling protein tag. Evolution of hAGT led not only to increased protein activity but also to higher stability, especially of the alkylated protein, suggesting that the reactivity of the suicide enzyme can be influenced by stabilizing the product of the irreversible reaction. Whereas wild-type hAGT ...

  3. Directed Evolution of the Suicide Protein O-6-Alkylguanine-DNA Alkyltransferase for Increased Reactivity Results in an Alkylated Protein with Exceptional Stability

    OpenAIRE

    Mollwitz, Birgit; Brunk, Elizabeth; Schmitt, Simone; Pojer, Florence; Bannwarth, Michael; Schiltz, Marc; Rothlisberger, Ursula; Johnsson, Kai

    2012-01-01

    Here we present a biophysical, structural, and computational analysis of the directed evolution of the human DNA repair protein O-6-alkylguanine-DNA alkyltransferase (hAGT) into SNAP-tag, a self-labeling protein tag. Evolution of hAGT led not only to increased protein activity but also to that the reactivity of the suicide enzyme can be influenced by higher stability, especially of the alkylated protein, suggesting stabilizing the product of the irreversible reaction. Whereas wild-type hAGT i...

  4. Increased arachidonic acid-containing phosphatidylcholine is associated with reactive microglia and astrocytes in the spinal cord after peripheral nerve injury.

    Science.gov (United States)

    Xu, Dongmin; Omura, Takao; Masaki, Noritaka; Arima, Hideyuki; Banno, Tomohiro; Okamoto, Ayako; Hanada, Mitsuru; Takei, Shiro; Matsushita, Shoko; Sugiyama, Eiji; Setou, Mitsutoshi; Matsuyama, Yukihiro

    2016-01-01

    Peripheral nerve injury (PNI) triggers cellular and molecular changes in the spinal cord. However, little is known about how the polyunsaturated fatty acid-containing phosphatidylcholines (PUFA-PCs) are regulated in the spinal cord after PNI and the association of PUFA-PCs with the non-neuronal cells within in the central nervous system (CNS). In this study, we found that arachidonic acid-containing phosphatidylcholine (AA-PC), [PC(16:0/20:4)+K](+), was significantly increased in the ipsilateral ventral and dorsal horns of the spinal cord after sciatic nerve transection, and the increased expression of [PC(16:0/20:4)+K](+) spatiotemporally resembled the increase of reactive microglia and the astrocytes. From the lipidomics point of view, we conclude that [PC(16:0/20:4)+K](+) could be the main phospholipid in the spinal cord influenced by PNI, and the regulation of specific phospholipid molecule in the CNS after PNI is associated with the reactive microglia and astrocytes. PMID:27210057

  5. 40 CFR 129.105 - Polychlorinated biphenyls (PCBs).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Polychlorinated biphenyls (PCBs). 129... Polychlorinated biphenyls (PCBs). (a) Specialized definitions. (1) PCB Manufacturer means a manufacturer who produces polychlorinated biphenyls. (2) Electrical capacitor manufacturer means a manufacturer who...

  6. Continuous flow augments reactivity of rabbit carotid artery by reducing bioavailability of NO despite an increase in release of EDHF

    DEFF Research Database (Denmark)

    Rasmussen, Lasse Enkebølle; Vanhoutte, Paul M. G.; Jensen, Boye L.; Skøtt, Ole

    2006-01-01

    endothelial small- and intermediate-conductance calcium-activated potassium channels by apamin plus 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34). These experiments demonstrate that continuous flow increases the constriction evoked by alpha(1)-adrenergic activation in the rabbit carotid artery...

  7. Hyperglycemia increases the expression levels of sclerostin in a reactive oxygen species- and tumor necrosis factor-alpha-dependent manner

    OpenAIRE

    Kang, Jiho; Boonanantanasarn, Kanitsak; Baek, Kyunghwa; Woo, Kyung Mi; Ryoo, Hyun-Mo; Baek, Jeong-Hwa; Kim, Gwan-Shik

    2015-01-01

    Purpose Sclerostin, an inhibitor of Wnt/β-catenin signaling, exerts negative effects on bone formation and contributes to periodontitis-induced alveolar bone loss. Recent studies have demonstrated that serum sclerostin levels are increased in diabetic patients and that sclerostin expression in alveolar bone is enhanced in a diabetic periodontitis model. However, the molecular mechanism of how sclerostin expression is enhanced in diabetic patients remains elusive. Therefore, in this study, the...

  8. Antenatal betamethasone increases vascular reactivity to endothelin-1 by upregulation of CD38/cADPR signaling

    OpenAIRE

    Lee, J.-H.; J. Zhang; Massmann, G. A.; Figueroa, J. P.

    2014-01-01

    Antenatal steroid administration is associated with hypertension in adult life; however, the mechanisms underlying this phenomenon are unclear. The aim of this study was to further characterize the effects of antenatal glucocorticoid exposure on the endothelin (ET-1) system, specifically to ascertain the role of the cyclic adenosine diphosphate ribose (cADPR)/ryanodine receptor pathway in the increased sensitivity to ET-1 observed in the offspring exposed to antenatal glucocorticoids. Pregnan...

  9. Emotion Reactivity Is Increased 4-6 Weeks Postpartum in Healthy Women: A Longitudinal fMRI Study

    OpenAIRE

    Gingnell, Malin; Bannbers, Elin; Moes, Harmen; Engman, Jonas; Sylvén, Sara; Skalkidou, Alkistis; Kask, Kristiina; Wikstrom, Johan; Sundström-Poromaa, Inger

    2015-01-01

    Marked endocrine alterations occur after delivery. Most women cope well with these changes, but the postpartum period is associated with an increased risk of depressive episodes. Previous studies of emotion processing have focused on maternal-infant bonding or postpartum depression (PPD), and longitudinal studies of the neural correlates of emotion processing throughout the postpartum period in healthy women are lacking. In this study, 13 women, without signs of post partum depression, underw...

  10. Degradation of polychlorinated biphenyls (PCBs) using palladized iron

    International Nuclear Information System (INIS)

    Contamination from polychlorinated biphenyls (PCBs) is a persistent problem within the Department of Energy complex, as well as in numerous industrial sites around the US. To date, commercially available technologies for destroying these highly stable compounds involve degradation at elevated temperatures either through incineration or base-catalyzed dehalogenation at 300 degrees C. Since the heating required with these processes substantially increases the costs for treatment of PCB-contaminated wastes, there is a need for finding an alternative approach where PCB can be degraded at ambient temperatures. This report describes the degradation of PCB's utilizing the bimetallic substrate of iron/palladium

  11. Degradation of polychlorinated biphenyls (PCBs) using palladized iron

    Energy Technology Data Exchange (ETDEWEB)

    West, O.R.; Liang, L.; Holden, W.L. [and others

    1996-06-01

    Contamination from polychlorinated biphenyls (PCBs) is a persistent problem within the Department of Energy complex, as well as in numerous industrial sites around the US. To date, commercially available technologies for destroying these highly stable compounds involve degradation at elevated temperatures either through incineration or base-catalyzed dehalogenation at 300{degrees}C. Since the heating required with these processes substantially increases the costs for treatment of PCB-contaminated wastes, there is a need for finding an alternative approach where PCB can be degraded at ambient temperatures. This report describes the degradation of PCB`s utilizing the bimetallic substrate of iron/palladium.

  12. Construction of a bioluminescent reporter strain to detect polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Layton, A.C.; Muccini, M.; Ghosh, M.M.; Sayler, G.S. [Univ. of Tennessee, Knoxville, TN (United States)

    1998-12-01

    A bioluminescent reporter strain, Ralstonia eutropha ENV307 (pUTK60), was constructed for the detection of polychlorinated biphenyls by inserting the biphenyl promoter upstream of the bioluminescence genes. In the presence of a nonionic surfactant, which enhances the solubility of chlorinated biphenyls, bioluminescence was induced three- to fourfold over background by biphenyl, monochlorinated biphenyls, and Aroclor 1242. The minimum detection limits for these compounds ranged from 0.15 mg/liter for 4-chlorobiphenyl to 1.5 mg/liter for Aroclor 1242.

  13. Adsorption And Simultaneous Dechlorination Of PCBs On GAC/Fe/Pd: Mechanistic Aspects And Reactive Capping Barrier Concept

    Science.gov (United States)

    There are many concerns and challenges in current remediation strategies for sediments contaminated with polychlorinated biphenyls (PCBs). Our efforts have been geared toward the development of granular activated carbon (GAC) impregnated with reactive iron/palladium (Fe/Pd) bime...

  14. Antibody Reactivity of B Cells in Lupus Patients with Increased Disease Activity and ARID3a Expression

    Directory of Open Access Journals (Sweden)

    Julie M. Ward

    2015-11-01

    Full Text Available Earlier studies showed that the DNA-binding protein, Bright/ARID3a bound to a subset of human and mouse immunoglobulin heavy chain promoters where it enhanced expression. Indeed, mice with transgenic expression of ARID3a in all B lymphocytes have expanded MZ B cells and produce anti-nuclear antibodies (ANAs. Consistent with our findings in mice, we observed that human systemic lupus erythematosus (SLE patients had expanded numbers of peripheral blood ARID3a+ B cells that were associated with increased disease activity (p = 0.0038. We hypothesized that ARID3a+ naïve B cells would eventually produce autoantibodies, explaining associations between ARID3a expression and disease activity in lupus. Unlike healthy controls, ARID3a was expressed in the naïve B cell population in SLE patients, and we hypothesized that these might represent expansions of autoreactive cells. Therefore, monoclonal antibodies were generated from single-sorted naïve B cells derived from patients with normal (ARID3aN and high (ARID3aH numbers of ARID3a+ B cells. We found that ARID3a expression did not correlate with autoantibody expression. Furthermore, measures of antigen specificities of autoreactive antibodies did not reveal skewing toward particular proteins. These data suggest that the association of increased disease activity in SLE with numbers of ARID3a+ B lymphocytes may be mediated by an antibody-independent mechanism.

  15. Plant enzymes in metabolism of polychlorinated biphenyls

    Czech Academy of Sciences Publication Activity Database

    Chromá, L.; Moeder, M.; Kučerová, P.; Macek, Tomáš; Macková, M.

    2003-01-01

    Roč. 12, č. 3 (2003), s. 291-295. ISSN 1018-4619 R&D Projects: GA MŠk ME 498 Institutional research plan: CEZ:AV0Z4055905 Keywords : polychlorinated biphenyls * plants * peroxidases Subject RIV: CE - Biochemistry Impact factor: 0.325, year: 2003

  16. C-reactive protein increases membrane fluidity and distorts lipid lateral organization of pulmonary surfactant. Protective role of surfactant protein A

    DEFF Research Database (Denmark)

    Saenz, Alejandra; Lopez-Sanchez, Almudena; Mojica-Lazaro, Jonas;

    2010-01-01

    The purpose of this study was to investigate how surfactant membranes can be perturbed by C-reactive protein (CRP) and whether surfactant protein A (SP-A) might overcome CRP-induced surfactant membrane alterations. The effect of CRP on surfactant surface adsorption was evaluated in vivo after...... intratracheal instillation of CRP into rat lungs. Insertion of CRP into surfactant membranes was investigated through monolayer techniques. The effect of CRP on membrane structure was studied through differential scanning calorimetry and fluorescence spectroscopy and microscopy using large and giant unilamellar...... vesicles. Our results indicate that CRP inserts into surfactant membranes and drastically increases membrane fluidity, resulting in surfactant inactivation. At 10% CRP/phospholipid weight ratio, CRP causes disappearance of liquid-ordered/liquid-disordered phase coexistence distinctive of surfactant...

  17. Protein kinase C-dependent increase in reactive oxygen species (ROS) production in vascular tissues of diabetes: role of vascular NAD(P)H oxidase.

    Science.gov (United States)

    Inoguchi, Toyoshi; Sonta, Toshiyo; Tsubouchi, Hirotaka; Etoh, Takashi; Kakimoto, Maiko; Sonoda, Noriyuki; Sato, Naoichi; Sekiguchi, Naotaka; Kobayashi, Kunihisa; Sumimoto, Hideki; Utsumi, Hideo; Nawata, Hajime

    2003-08-01

    Hyperglycemia seems to be an important causative factor in the development of micro- and macrovascular complications in patients with diabetes. Several hypotheses have been proposed to explain the adverse effects of hyperglycemia on vascular cells. Both protein kinase C (PKC) activation and oxidative stress theories have increasingly received attention in recent years. This article shows a PKC-dependent increase in oxidative stress in diabetic vascular tissues. High glucose level stimulated reactive oxygen species (ROS) production via a PKC-dependent activation of NAD(P)H oxidase in cultured aortic endothelial cells, smooth muscle cells, and renal mesangial cells. In addition, expression of NAD(P)H oxidase components were shown to be upregulated in vascular tissues and kidney from animal models of diabetes. Furthermore, several agents that were expected to block the mechanism of a PKC-dependent activation of NAD(P)H oxidase clearly inhibited the increased oxidative stress in diabetic animals, as assessed by in vivo electron spin resonance method. Taken together, these findings strongly suggest that the PKC-dependent activation of NAD(P)H oxidase may be an essential mechanism responsible for increased oxidative stress in diabetes. PMID:12874436

  18. High locomotor reactivity to novelty is associated with an increased propensity to choose saccharin over cocaine: new insights into the vulnerability to addiction.

    Science.gov (United States)

    Vanhille, Nathalie; Belin-Rauscent, Aude; Mar, Adam C; Ducret, Eric; Belin, David

    2015-02-01

    Drug addiction is associated with a relative devaluation of natural or socially-valued reinforcers that are unable to divert addicts from seeking and consuming the drug. Before protracted drug exposure, most rats prefer natural rewards, such as saccharin, over cocaine. However, a subpopulation of animals prefer cocaine over natural rewards and are thought to be vulnerable to addiction. Specific behavioral traits have been associated with different dimensions of drug addiction. For example, anxiety predicts loss of control over drug intake whereas sensation seeking and sign-tracking are markers of a greater sensitivity to the rewarding properties of the drug. However, how these behavioral traits predict the disinterest for natural reinforcers remains unknown. In a population of rats, we identified sensation seekers (HR) on the basis of elevated novelty-induced locomotor reactivity, high anxious rats (HA) based on the propensity to avoid open arms in an elevated-plus maze and sign-trackers (ST) that are prone to approach, and interaction with, reward-associated stimuli. Rats were then tested on their preference for saccharin over cocaine in a discrete-trial choice procedure. We show that HR rats display a greater preference for saccharin over cocaine compared with ST and HA whereas the motivation for the drug was comparable between the three groups. The present data suggest that high locomotor reactivity to novelty, or sensation seeking, by predisposing to an increased choice toward non-drug rewards at early stages of drug use history, may prevent the establishment of chronic cocaine use. PMID:25120076

  19. Study of tritium labeling of complex mixture of polychlorinated biphenyls

    International Nuclear Information System (INIS)

    The method for tritium labeling of technical mixture (commercial mark - SOVOL, USSR) of polychlorinated biphenyls (PCBs) was developed. The influence of procedure of labeling by thermally activated tritium on the nativity of polychlorinated biphenyls (PCBs) was studied. The method of labeling by thermally activated tritium has some factors, which are able to destroy organic compounds - photodegradation, thermo-degradation and degradation caused by reaction of substitution of organic compounds hydrogen atoms by activated tritium atoms. To develop a method of labeling of every organic compound by thermally activated tritium it is necessary to determine and optimize the conditions of labeling. In our case procedure of labeling is complicated because of technical mixture of PCBs consist from more than 20 isomers, chlorinated with different degree. We studied the dependence of appearance of products of degradation PCBs from duration of labeling procedure. It was found that some part of PCBs and product of its degradation were evaporated under vacuum and were collected on the glass flask cooled by liquid nitrogen. It was found that correlation between labeled of PCBs and products of degradation did not changed with increasing time of labeling, and radiochemical yield of tritium labeled of PCBs was stable - about 15-20 %. The optimum regime of labeling was selected. It was found that purification of labeled PCBs by TLC on silica gel with hexane allows obtaining tritium-labeled PCBs purified from by-products. Thus, TLC purification seems inexpensive, fast and suitable for purification of tritium-labeled PCBs

  20. Polychlorinated biphenyl residues in sandstorm depositions in Beijing, China.

    Science.gov (United States)

    Fu, Shan; Yang, Zhong-Zhi; Li, Ke; Xu, Xiao-Bai

    2008-10-01

    Sandstorms, which distribute many particles, are a special atmospheric occurrence and are frequent in northern China. We conducted this study to determine, for the first time, the concentration of polychlorinated biphenyls (PCBs) in sandstorm depositions. We collected 13 samples from urban areas of Beijing, and we measured a total of 144 PCB congeners. Thirteen samples all contained PCB residues. The total PCB concentration ranged from 1.6 to 15.6ngg(-1) (median, 4.8ngg(-1), dry weight), with trichlorinated biphenyls as the predominant homologue (>50.4%). Furthermore, we observed increasing PCB contamination from northwest to east Beijing. We later explored possible factors affecting contamination of the sandstorm depositions, which revealed a significant correlation between SigmaPCBs and the minimum particle size of the sandstorm deposition samples. Principal-component analysis revealed that the major source of PCBs in Beijing may be potentially associated with the number-one commercial PCB through the long-range transmission. In previous results, PCBs were not a severe component of contamination in sandstorm depositions of Beijing. However, this study suggested that sandstorm deposition may be a potential source of exposure to PCBs for the residents of Beijing, China. PMID:18674798

  1. Occupational exposure to polychlorinated biphenyls (PCBs).

    OpenAIRE

    Wolff, M S

    1985-01-01

    Human occupational exposure to polychlorinated biphenyls (PCBs) with varying chlorine content has been reported by several investigators, using analyses of blood or adipose samples or skin wipes to evaluate levels in the body. The intensity of occupational exposure is related to both duration and intensity of exposure. The qualitative nature of occupational exposure, as well as casual environmental exposure, has been shown to consist of less readily metabolized PCB congeners. The pattern of P...

  2. ADSORPTION OF POLYCHLORINATED BIPHENYLS BY SOILS

    OpenAIRE

    Mihaela Preda; Radu Lăcătuşu; Dumitru Marian Motelică; Nicoleta Vrînceanu; Veronica Tănase

    2010-01-01

    The behavior of polychlorinated biphenyls (PCBs) in soil is determined by several factors including adsorption, mobility and degradation. Adsorption, directly or indirectly, influences the other factors. Adsorption process is generally evaluated by using adsorption isotherms representing the relationship between the quantity of substance adsorbed per unit weight and concentration of the substance in solution at equilibrium. They allow determination of the adsorption constant, which is directl...

  3. Metabolic and health consequences of occupational exposure to polychlorinated biphenyls.

    OpenAIRE

    Smith, A B; Schloemer, J; Lowry, L K; Smallwood, A W; Ligo, R N; Tanaka, S.; Stringer, W; Jones, M; Hervin, R; Glueck, C J

    1982-01-01

    In surveys of three groups of workers occupationally exposed to polychlorinated biphenyls (PCBs) serum PCB concentrations were quantitated as lower chlorinated biphenyls (L-PCBs) and higher chlorinated biphenyls (H-PCBs). Serum L-PCB and H-PCB concentrations were many times greater among workers employed in power capacitor manufacturing than exposed areas. Statistically significant positive correlations of symptoms suggestive of mucous membrane and skin irritation, of systemic malaise, and al...

  4. Reactive Systems

    DEFF Research Database (Denmark)

    Aceto, Luca; Ingolfsdottir, Anna; Larsen, Kim Guldstrand;

    A reactive system comprises networks of computing components, achieving their goals through interaction among themselves and their environment. Thus even relatively small systems may exhibit unexpectedly complex behaviours. As moreover reactive systems are often used in safety critical systems......, the need for mathematically based formal methodology is increasingly important. There are many books that look at particular methodologies for such systems. This book offers a more balanced introduction for graduate students and describes the various approaches, their strengths and weaknesses, and when...... they are best used. Milner's CCS and its operational semantics are introduced, together with the notions of behavioural equivalences based on bisimulation techniques and with recursive extensions of Hennessy-Milner logic. In the second part of the book, the presented theories are extended to take timing issues...

  5. Catalytic Role Of Palladium And Relative Reactivity Of Substituted Chlorines During Adsorption And Treatment Of PCBs On Reactive Activated Carbon

    Science.gov (United States)

    The adsorption-mediated dechlorination of polychlorinated biphenyls (PCBs) is a unique feature of reactive activated cabon (RAC). Here, we address the RAC system, containing a tunable amount of Fe as a primary electron donor coupled with Pd as an electrochemical catalyst to pote...

  6. Insights on the antitumor effects of kahweol on human breast cancer: Decreased survival and increased production of reactive oxygen species and cytotoxicity

    International Nuclear Information System (INIS)

    Highlights: • Kahweol inhibits growth and attachment-independent proliferation of tumor cells. • Kahweol induces apoptosis in MDA-MB231 human breast cancer cells. • Kahweol-induced apoptosis involves caspase activation and cytochrome c release. • Kahweol does not protect against hydrogen peroxide cytotoxicity. • Kahweol increases hydrogen peroxide production by human breast cancer cells. - Abstract: The present study aims to identify the modulatory effects of kahweol, an antioxidant diterpene present in coffee beans, on a panel of human tumor cell lines. Kahweol inhibits tumor cell proliferation and clonogenicity and induces apoptosis in several kinds of human tumor cells. In the estrogen receptor-negative MDA-MB231 human breast cancer, the mentioned effects are accompanied by caspases 3/7 and 9 activation and cytochrome c release. On the other hand, kahweol increases the production of reactive oxygen species and their cytotoxicity in human breast cancer cells but not in normal cells. Taken together, our data suggest that kahweol is an antitumor compound with inhibitory effects on tumor cell growth and survival, especially against MDA-MB231 breast cancer cells

  7. Insights on the antitumor effects of kahweol on human breast cancer: Decreased survival and increased production of reactive oxygen species and cytotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Cárdenas, Casimiro [Department of Molecular Biology and Biochemistry, Faculty of Sciences, University of Málaga, E-29071 Málaga (Spain); IBIMA (Biomedical Research Institute of Málaga), E-29071 Málaga (Spain); Research Support Central Services (SCAI) of the University of Málaga, E-29071 Málaga (Spain); Quesada, Ana R. [Department of Molecular Biology and Biochemistry, Faculty of Sciences, University of Málaga, E-29071 Málaga (Spain); IBIMA (Biomedical Research Institute of Málaga), E-29071 Málaga (Spain); CIBER de Enfermedades Raras (CIBERER), E-29071 Málaga (Spain); Medina, Miguel Ángel, E-mail: medina@uma.es [Department of Molecular Biology and Biochemistry, Faculty of Sciences, University of Málaga, E-29071 Málaga (Spain); IBIMA (Biomedical Research Institute of Málaga), E-29071 Málaga (Spain); CIBER de Enfermedades Raras (CIBERER), E-29071 Málaga (Spain)

    2014-05-09

    Highlights: • Kahweol inhibits growth and attachment-independent proliferation of tumor cells. • Kahweol induces apoptosis in MDA-MB231 human breast cancer cells. • Kahweol-induced apoptosis involves caspase activation and cytochrome c release. • Kahweol does not protect against hydrogen peroxide cytotoxicity. • Kahweol increases hydrogen peroxide production by human breast cancer cells. - Abstract: The present study aims to identify the modulatory effects of kahweol, an antioxidant diterpene present in coffee beans, on a panel of human tumor cell lines. Kahweol inhibits tumor cell proliferation and clonogenicity and induces apoptosis in several kinds of human tumor cells. In the estrogen receptor-negative MDA-MB231 human breast cancer, the mentioned effects are accompanied by caspases 3/7 and 9 activation and cytochrome c release. On the other hand, kahweol increases the production of reactive oxygen species and their cytotoxicity in human breast cancer cells but not in normal cells. Taken together, our data suggest that kahweol is an antitumor compound with inhibitory effects on tumor cell growth and survival, especially against MDA-MB231 breast cancer cells.

  8. Chronic carbon monoxide exposure is associated with the increases in carotid intima-media thickness and C-reactive protein level.

    Science.gov (United States)

    Davutoglu, Vedat; Zengin, Suat; Sari, Ibrahim; Yildirim, Cuma; Al, Behcet; Yuce, Murat; Ercan, Suleyman

    2009-11-01

    Being the most common cause of death from poisoning worldwide, cardiovascular manifestations of acute carbon monoxide (CO) poisoning have been subject of various studies but current evidence about effects of chronic CO exposure on atherosclerosis is limited which is very common. We aimed to investigate association of chronic CO exposure with atherosclerosis by measuring carotid intima-media thickness (CIMT) and high-sensitivity C-reactive protein (hs-CRP). Forty healthy male non-smoker indoor barbecue workers (mean age; 33.0 +/- 9.0 years) working in different restaurants for at least three years and 48 age-matched healthy men (mean age; 34.3 +/- 6.6 years) enrolled in the study. Clinical characteristics of indoor barbecue workers and control group were comparable in terms of body mass index, blood pressure, and lipid profile. However, carboxyhemoglobin (COHb) (6.4 +/- 1.5% vs. 2.0 +/- 1.1%), hs-CRP (2.7 +/- 2.0 mg/L vs. 1.1 +/- 0.8 mg/L) and CIMT (1.1 +/- 0.3 mm vs. 0.9 +/- 0.1 mm) were higher in indoor barbecue workers (p independent predictor of CIMT (beta = 0.571, p < 0.001). The increased CIMT and hs-CRP in indoor barbecue workers suggest that chronic CO exposure may increase the risk of atherosclerotic cardiovascular events. PMID:19851048

  9. 77 FR 42181 - Polychlorinated Biphenyls (PCBs); Disposition of Request Submitted Under TSCA Section 21

    Science.gov (United States)

    2012-07-18

    ... AGENCY 40 CFR Chapter I Polychlorinated Biphenyls (PCBs); Disposition of Request Submitted Under TSCA... certain actions to protect human health and the marine environment from polychlorinated biphenyls (PCBs... Sinking Exercise). List of Subjects Environmental protection, Polychlorinated biphenyls, SINKEX....

  10. Increase of HLA-DRB1*0408 and -DQB1*0301 in HLA-B27 positive reactive arthritis

    OpenAIRE

    Tuokko, J; Reijonen, H.; Ilonen, J; K. Anttila; Nikkari, S; Mottonen, T; Yli-Kerttula, U; Toivanen, A

    1997-01-01

    OBJECTIVE—To study HLA class II association in reactive arthritis.
METHODS—63 patients with reactive arth-ritis and 46 with rheumatoid arthritis were included in the study. HLA-DR alleles were determined by using a sequence specific PCR method. Oligonucleotide hybridisation was used for definition of DRB1*04 subtypes and DQB1 alleles. HLA-B27 was determined by standard microcytotoxity test or by PCR. HLA-B27 subtyping was made by sequencing.
RESULTS—46 (73%) of 63 patients with reactive arthr...

  11. Tryptamine and dimethyltryptamine inhibit indoleamine 2,3 dioxygenase and increase the tumor-reactive effect of peripheral blood mononuclear cells.

    Science.gov (United States)

    Tourino, Melissa Cavalheiro; de Oliveira, Edson Mendes; Bellé, Luziane Potrich; Knebel, Franciele Hinterholz; Albuquerque, Renata Chaves; Dörr, Felipe Augusto; Okada, Sabrina Sayori; Migliorini, Silene; Soares, Irene Silva; Campa, Ana

    2013-07-01

    Indoleamine 2,3-dioxygenase (IDO) is an interferon-γ (IFN-γ)-induced tryptophan-degrading enzyme, producing kynurenine (KYN) that participates in the mechanism of tumor immune tolerance. Thus, IDO inhibition has been considered a strategy for anticancer therapy. The aim of this study was to identify whether the metabolites originated from the competitive routes of tryptophan metabolism, such as the serotonergic or N, N-dimethyltryptamine (DMT) pathways, have inhibitory effects on recombinant human IDO (rhIDO) activity. Serotonin and melatonin had no effect; on the other hand, tryptamine (TRY) and DMT modulated the activity of rhIDO as classical non-competitive inhibitors, with Ki values of 156 and 506 μM, respectively. This inhibitory effect was also observed on constitutively expressed or IFN-γ-induced IDO in the A172 human glioma cell line. TRY and DMT increased the cytotoxic activity of peripheral blood mononuclear cells (PBMCs) in co-culture assays. We conclude that the IDO inhibition by TRY and DMT contributed to a more effective tumor-reactive response by the PBMCs. PMID:23754498

  12. Metformin Decreases Reactive Oxygen Species, Enhances Osteogenic Properties of Adipose-Derived Multipotent Mesenchymal Stem Cells In Vitro, and Increases Bone Density In Vivo.

    Science.gov (United States)

    Marycz, Krzysztof; Tomaszewski, Krzysztof A; Kornicka, Katarzyna; Henry, Brandon Michael; Wroński, Sebastian; Tarasiuk, Jacek; Maredziak, Monika

    2016-01-01

    Due to its pleiotropic effects, the commonly used drug metformin has gained renewed interest among medical researchers. While metformin is mainly used for the treatment of diabetes, recent studies suggest that it may have further application in anticancer and antiaging therapies. In this study, we investigated the proliferative potential, accumulation of oxidative stress factors, and osteogenic and adipogenic differentiation potential of mouse adipose-derived stem cells (MuASCs) isolated from mice treated with metformin for 8 weeks. Moreover, we investigated the influence of metformin supplementation on mice bone density and bone element composition. The ASCs isolated from mice who were treated with metformin for 8 weeks showed highest proliferative potential, generated a robust net of cytoskeletal projections, had reduced expression of markers associated with cellular senescence, and decreased amount of reactive oxygen species in comparison to control group. Furthermore, we demonstrated that these cells possessed greatest osteogenic differentiation potential, while their adipogenic differentiation ability was reduced. We also demonstrated that metformin supplementation increases bone density in vivo. Our result stands as a valuable source of data regarding the in vivo influence of metformin on ASCs and bone density and supports a role for metformin in regenerative medicine. PMID:27195075

  13. Metformin Decreases Reactive Oxygen Species, Enhances Osteogenic Properties of Adipose-Derived Multipotent Mesenchymal Stem Cells In Vitro, and Increases Bone Density In Vivo

    Directory of Open Access Journals (Sweden)

    Krzysztof Marycz

    2016-01-01

    Full Text Available Due to its pleiotropic effects, the commonly used drug metformin has gained renewed interest among medical researchers. While metformin is mainly used for the treatment of diabetes, recent studies suggest that it may have further application in anticancer and antiaging therapies. In this study, we investigated the proliferative potential, accumulation of oxidative stress factors, and osteogenic and adipogenic differentiation potential of mouse adipose-derived stem cells (MuASCs isolated from mice treated with metformin for 8 weeks. Moreover, we investigated the influence of metformin supplementation on mice bone density and bone element composition. The ASCs isolated from mice who were treated with metformin for 8 weeks showed highest proliferative potential, generated a robust net of cytoskeletal projections, had reduced expression of markers associated with cellular senescence, and decreased amount of reactive oxygen species in comparison to control group. Furthermore, we demonstrated that these cells possessed greatest osteogenic differentiation potential, while their adipogenic differentiation ability was reduced. We also demonstrated that metformin supplementation increases bone density in vivo. Our result stands as a valuable source of data regarding the in vivo influence of metformin on ASCs and bone density and supports a role for metformin in regenerative medicine.

  14. Metformin Decreases Reactive Oxygen Species, Enhances Osteogenic Properties of Adipose-Derived Multipotent Mesenchymal Stem Cells In Vitro, and Increases Bone Density In Vivo

    Science.gov (United States)

    Marycz, Krzysztof; Tomaszewski, Krzysztof A.; Kornicka, Katarzyna; Henry, Brandon Michael; Wroński, Sebastian; Tarasiuk, Jacek; Maredziak, Monika

    2016-01-01

    Due to its pleiotropic effects, the commonly used drug metformin has gained renewed interest among medical researchers. While metformin is mainly used for the treatment of diabetes, recent studies suggest that it may have further application in anticancer and antiaging therapies. In this study, we investigated the proliferative potential, accumulation of oxidative stress factors, and osteogenic and adipogenic differentiation potential of mouse adipose-derived stem cells (MuASCs) isolated from mice treated with metformin for 8 weeks. Moreover, we investigated the influence of metformin supplementation on mice bone density and bone element composition. The ASCs isolated from mice who were treated with metformin for 8 weeks showed highest proliferative potential, generated a robust net of cytoskeletal projections, had reduced expression of markers associated with cellular senescence, and decreased amount of reactive oxygen species in comparison to control group. Furthermore, we demonstrated that these cells possessed greatest osteogenic differentiation potential, while their adipogenic differentiation ability was reduced. We also demonstrated that metformin supplementation increases bone density in vivo. Our result stands as a valuable source of data regarding the in vivo influence of metformin on ASCs and bone density and supports a role for metformin in regenerative medicine. PMID:27195075

  15. Trastuzumab, but Not Pertuzumab, Dysregulates HER2 Signaling to Mediate Inhibition of Autophagy and Increase in Reactive Oxygen Species Production in Human Cardiomyocytes.

    Science.gov (United States)

    Mohan, Nishant; Shen, Yi; Endo, Yukinori; ElZarrad, M Khair; Wu, Wen Jin

    2016-06-01

    Dysregulation of autophagy has been implicated in various cardiovascular diseases. Trastuzumab, a humanized monoclonal antibody, binds to HER2 domain IV and is approved for the treatment of HER2-positive breast cancer. Trastuzumab therapy is associated with considerable cardiotoxicity, the mechanism of which remains unclear. HER2 signaling plays a pivotal role in cardiomyocyte development and survival and is essential for the prevention of cardiomyopathy. However, a direct link has not been confirmed between trastuzumab-induced cardiomyopathy and impaired HER2 signaling. Our data reveal a novel mechanism by which trastuzumab dysregulates HER2 signaling and impairs basal autophagic process in human primary cardiomyocytes. Specifically, trastuzumab treatment leads to the phosphorylation of HER1-Y845 and HER2-Y1248 and the activation of Erk. This in turn results in upregulation of mTOR signaling pathway and subsequently inhibition of autophagy in primary cardiomyocytes and C57BL/6 mice. Trastuzumab-induced downregulation of autophagy is further supported by the fact that trastuzumab treatment reduces protein levels of autophagosome-associated signaling molecules such as Atg 5-12, Atg 7, Atg 14, and Beclin 1. We further demonstrated that trastuzumab-mediated inhibition of autophagy resulted in the increased production of reactive oxygen species (ROS) in cardiomyocytes. Pertuzumab, another anti-HER2 therapeutic mAb binding to HER2 domain II, fails to modulate HER2 signaling and is unable to inhibit autophagy and to increase ROS production in cardiomyocytes. This study provides novel mechanistic insights into trastuzumab-induced cardiotoxicity, which may assist in formulating novel approaches for clinical management of trastuzumab-induced cardiomyopathy. Mol Cancer Ther; 15(6); 1321-31. ©2016 AACR. PMID:27197303

  16. Increased cardiovascular reactivity to acute stress and salt-loading in adult male offspring of fat fed non-obese rats.

    Directory of Open Access Journals (Sweden)

    Olena Rudyk

    Full Text Available Diet-induced obesity in rat pregnancy has been shown previously to be associated with consistently raised blood pressure in the offspring, attributed to sympathetic over-activation, but the relative contributions to this phenotype of maternal obesity versus raised dietary fat is unknown. Sprague-Dawley female rats were fed either a control (4.3% fat, n = 11 or lard-enriched (23.6% fat, n = 16 chow 10 days prior to mating, throughout pregnancy and lactation. In conscious adult (9-month-old offspring cardiovascular parameters were measured (radiotelemetry. The short period of fat-feeding did not increase maternal weight versus controls and the baseline blood pressure was similar in offspring of fat fed dams (OF and controls (OC. However, adult male OF showed heightened cardiovascular reactivity to acute restraint stress (p<0.01; Δ systolic blood pressure (SBP and Δheart rate (HR with a prolonged recovery time compared to male OC. α1/β-adrenergic receptor blockade normalised the response. Also, after dietary salt-loading (8%-NaCl ad libitum for 1 week male OF demonstrated higher SBP (p<0.05 in the awake phase (night-time and increased low/high frequency ratio of power spectral density of HR variability versus OC. Baroreflex gain and basal power spectral density components of the heart rate or blood pressure were similar in male OF and OC. Minor abnormalities were evident in female OF. Fat feeding in the absence of maternal obesity in pregnant rats leads to altered sympathetic control of cardiovascular function in adult male offspring, and hypertension in response to stressor stimuli.

  17. The effect of increasing V content on the structure, mechanical properties and oxidation resistance of Ti–Si–V–N films deposited by DC reactive magnetron sputtering

    International Nuclear Information System (INIS)

    In the last years, vanadium rich films have been introduced as possible candidates for self-lubrication at high temperatures, based on the formation of V2O5 oxide. The aim of this investigation was to study the effect of V additions on the structure, mechanical properties and oxidation resistance of Ti–Si–V–N coatings deposited by DC reactive magnetron sputtering. The results achieved for TiSiVN films were compared and discussed in relation to TiN and TiSiN films prepared as reference. All coatings presented a fcc NaCl-type structure. A shift of the diffraction peaks to higher angles with increasing Si and V contents suggested the formation of a substitutional solid solution in TiN phase. Hardness and Young's modulus of the coatings were similar regardless on V content. The onset of oxidation of the films decreased significantly to 500 °C when V was added into the films; this behaviour was independent of the Si and V contents. The thermogravimetric isothermal curves of TiSiVN coatings oxidized at temperatures below the melting point of α-V2O5 (∼685 °C) showed two stages: at an early stage, the weight increase over time is linear, whilst, in the second stage, a parabolic evolution can be fitted to the experimental data. At higher temperatures only a parabolic evolution was fitted. α-V2O5 was the main phase detected at the oxidized surface of the coatings. Reduction of α-V2O5 to β-V2O5 phase occurred for temperatures above its melting point.

  18. The effect of increasing V content on the structure, mechanical properties and oxidation resistance of Ti-Si-V-N films deposited by DC reactive magnetron sputtering

    Science.gov (United States)

    Fernandes, F.; Loureiro, A.; Polcar, T.; Cavaleiro, A.

    2014-01-01

    In the last years, vanadium rich films have been introduced as possible candidates for self-lubrication at high temperatures, based on the formation of V2O5 oxide. The aim of this investigation was to study the effect of V additions on the structure, mechanical properties and oxidation resistance of Ti-Si-V-N coatings deposited by DC reactive magnetron sputtering. The results achieved for TiSiVN films were compared and discussed in relation to TiN and TiSiN films prepared as reference. All coatings presented a fcc NaCl-type structure. A shift of the diffraction peaks to higher angles with increasing Si and V contents suggested the formation of a substitutional solid solution in TiN phase. Hardness and Young's modulus of the coatings were similar regardless on V content. The onset of oxidation of the films decreased significantly to 500 °C when V was added into the films; this behaviour was independent of the Si and V contents. The thermogravimetric isothermal curves of TiSiVN coatings oxidized at temperatures below the melting point of α-V2O5 (∼685 °C) showed two stages: at an early stage, the weight increase over time is linear, whilst, in the second stage, a parabolic evolution can be fitted to the experimental data. At higher temperatures only a parabolic evolution was fitted. α-V2O5 was the main phase detected at the oxidized surface of the coatings. Reduction of α-V2O5 to β-V2O5 phase occurred for temperatures above its melting point.

  19. Removal of polychlorinated biphenyls by desulfurization and emissions of polychlorinated biphenyls from sintering plants.

    Science.gov (United States)

    Wang, Mengjing; Hou, Meifang; Zhao, Kai; Li, Haifeng; Han, Ying; Liao, Xiao; Chen, Xuebin; Liu, Wenbin

    2016-04-01

    The influence of desulfurization on polychlorinated biphenyls (PCBs) from sintering plants was investigated. The concentrations of dioxin-like (dl) PCBs, toxic equivalents (TEQs), indicator PCBs, and total tri- to deca-chlorinated PCB homolog groups (∑PCBs) in the flue gases at the desulfurization system inlets were 290-1906 pg m(-3) (2.4-18.8 pg World Health Organization (WHO) TEQ m(-3)), 420-2885 pg m(-3), and 6496-22,648 pg m(-3), respectively. Desulfurization reduced the values to 43.3-500 pg m(-3) (0.46-9.5 pg WHO-TEQ m(-3)), 183-587 pg m(-3), and 2383-11,639 pg m(-3), respectively. The removed PCBs were adsorbed by gypsum from the flue gas; the PCB concentration distributions at the inlets and outlets and in the gypsum samples were similar. The emission factors were 9.86 ng WHO-TEQ t(-1) for the flue gas and 8.37 ng WHO-TEQ t(-1) for gypsum. Desulfurization decreased the annual atmospheric PCB emissions from 48.6 to 30.7 g WHO-TEQ, and the estimated annual emissions in gypsum were 8.06 g WHO-TEQ. PCBs in the gypsum have not been effectively eliminated and will probably reenter the environment and in turn become a new source of PCB emission. The PCB concentrations in fly ashes from series-connected electrostatic precipitators clearly increased. PMID:26690582

  20. Kinetics of polychlorinated biphenyl partitioning to marine Chrysophyte Isochrysis galbana

    International Nuclear Information System (INIS)

    This study focused on the uptake kinetics of polychlorinated biphenyl (PCB) congeners by the Chrysophyte, Isochrysis galbana. A gas-purging experimental system was used to maintain constant dissolved PCB concentrations. Three phases of absorption were observed: first, a rapid absorption phase within the first 15 min, second, a first order process reaching the maximum concentration within 48 h of exposure, and third, a plateau phase as yet to be determined with very slight increases in concentration. In this study, the percentage of the maximum concentration reached within the first phase varied from 10% to 67%, depending on the size of the PCB (as determined by molecular weight and total surface area), whereas the uptake rate (ku) during the second phase was more comparable across different PCBs. In addition, for the first phase, the bioconcentration factor (BCF) of PCBs deviated from its expected relationship with hydrophobicity, as determined by Kow, and was instead related to the molecular structure of the compound.

  1. Sulfate radical-based degradation of polychlorinated biphenyls: Effects of chloride ion and reaction kinetics

    International Nuclear Information System (INIS)

    Highlights: ► A kinetic model was used to predict the radical species and their distributions. ► The generated radical species were identified by EPR. ► The second-order rate constants of sulfate radical with PCBs were determined. - Abstract: Advanced oxidation processes (AOPs) based on sulfate radical (SO4·−) have been recently used for soil and groundwater remediation. The presence of chloride ion in natural or wastewater decreases the reactivity of sulfate radical system, but explanations for this behavior were inconsistent, and the mechanisms are poorly understood. Therefore, in this paper we investigated the effect of chloride ion on the degradation of 2,4,4′-CB (PCB28) and biphenyl (BP) by persulfate, based on the produced SO4·−. The results showed that the presence of chloride ion greatly inhibited the transformation of PCB28 and BP. Transformation intermediates of BP were monitored, suggesting that the chloride ion can react with SO4·− to produce chlorine radical, which reacts with BP to generate chlorinated compounds. To better understand the underlying mechanisms of these processes, a kinetic model was developed for predicting the effect of chloride ion on the types of radical species and their distributions. The results showed that chloride ion could influence the selectivity of radical species and their distribution, and increase the concentration of the sum of radical species. In addition, the second-order rate constants of sulfate radical with PCBs were determined, and quantum-chemical descriptors were introduced to predict the rate constants of other PCBs based on our experimental data.

  2. Combination of high-sensitivity C-reactive protein and homocysteine may predict an increased risk of coronary artery disease in Korean population

    Institute of Scientific and Technical Information of China (English)

    CHO Doo-Yeoun; KIM Kyu-Nam; KIM Kwang-Min; LEE Duck-Joo; KIM Bom-Taeck

    2012-01-01

    Background The association of emerging biomarkers such as high-sensitivity C-reactive protein (hs-CRP),homocysteine and fibrinogen with the risk of coronary artery disease (CAD) is still uncertain in Asian population including Koreans and little is known about the combined effect of biomarkers on the risk of CAD.Methods A total of 10 650 subjects (6538 men and 4112 women) were enrolled in this study.A 10-year CAD risk was calculated using Framingham risk score modified by the National Cholesterol Education Program (NCEP) Adult Treatment Panel Ⅲ (ATP Ⅲ ) and levels of circulating hs-CRP,homocysteine and fibrinogen were measured using validated assays.Results The 10-year CAD risk gradually augmented with increase in the circulating levels of hs-CRP,homocysteine and fibrinogen.For the highest quartile of hs-CRP,odds ratio (OR) of high-risk for CAD (10-year risk ≥20%) compared with the lowest quartile was 3.97 (95% C/:2.51-6.29).For homocysteine and fibrinogen,ORs in the highest quartile compared to the lowest quartile were 5.10 (95% Cl:3.05-8.53,P <0.001) and 1.46 (95% Cl:0.69-3.11,P=0.325),respectively.OR of high-risk for CAD in both the highest quartile of hs-CRP and homocysteine was 9.05 (95% CI:5.30-15.45) compared with the below median of hs-CRP and homocysteine.Conclusions The present study demonstrated that hs-CRP and homocysteine are well associated with the 10-year CAD risk estimated using NCEP ATP Ⅲ in Koreans and combination of hs-CRP and homocysteine can have strong synergyin predicting the development of CAD.

  3. Effect of Quercetin on Haematobiochemical and Histological Changes in the Liver of Polychlorined Biphenyls-Induced Adult Male Wistar Rats

    OpenAIRE

    Kandaswamy Selvakumar; Senthamilselvan Bavithra; Sekaran Suganya; Firdous Ahmad Bhat; Gunasekaran Krishnamoorthy; Jagadeesan Arunakaran

    2013-01-01

    Polychlorinated biphenyls exposure damages the rat liver cells. Hematological parameters such as hemoglobin, packed cell volume, red-blood cells, white-blood cells, neutrophils, platelet counts, and RBC indices were significantly decreased. Polymorphs, eosinophil counts, and erythrocyte sedimentation rate were significantly increased. Serum liver enzymes such as aspartate transaminase, alanine transaminase, alkaline phosphatase, and gamma-glutamyl transferase were increased by PCBs treatment....

  4. 2,3,7,8-Tetrachlorodibenzo-p-dioxin increases reactive oxygen species production in human endothelial cells via induction of cytochrome P4501A1

    International Nuclear Information System (INIS)

    Studies in our laboratory have demonstrated that subchronic 2,3,7,8,-tetrachlorodibenzo-p-dioxin (TCDD) exposure of adult mice results in hypertension, cardiac hypertrophy, and reduced nitric oxide (NO)-mediated vasodilation. Moreover, increased superoxide anion production was observed in cardiovascular organs of TCDD-exposed mice and this increase contributed to the reduced NO-mediated vasodilation. Since cytochrome P4501A1 (CYP1A1) can contribute to some TCDD-induced toxicity, we tested the hypothesis that TCDD increases reactive oxygen species (ROS) in endothelial cells by the induction of CYP1A1. A concentration-response to 24 h TCDD exposure (10 pM-10 nM) was performed in confluent primary human aortic endothelial cells (HAECs). Oxidant-sensitive fluorescent probes dihydroethidium (DHE) and 2',7'-dichlorofluorescin diacetate (DCFH-DA), were used to measure superoxide anion, and hydrogen peroxide and hydroxyl radical, respectively. NO was also measured using the fluorescent probe diaminofluorescein-2 diacetate (DAF-2DA). These assessments were conducted in HAECs transfected with siRNA targeting the aryl hydrocarbon receptor (AhR), CYP1A1, or CYP1B1. TCDD concentration-dependently increased CYP1A1 and CYP1B1 mRNA, protein, and enzyme activity. Moreover, 1 nM TCDD maximally increased DHE (Cont = 1.0 ± 0.3; TCDD = 5.1 ± 1.0; p = 0.002) and DCFH-DA (Cont = 1.0 ± 0.2; TCDD = 4.1 ± 0.5; p = 0.002) fluorescence and maximally decreased DAF-2DA fluorescence (Cont = 1.0 ± 0.4; TCDD = 0.68 ± 0.1). siRNA targeting AhR and CYP1A1 significantly decreased TCDD-induced DHE (siAhR: Cont = 1.0 ± 0.1; TCDD = 1.3 ± 0.2; p = 0.093) (siCYP1A1: Cont = 1.0 ± 0.1; TCDD = 1.1 ± 0.1; p = 0.454) and DCFH-DA (siAhR: Cont = 1.0 ± 0.2; TCDD = 1.3 ± 0.3; p = 0.370) (siCYP1A1: Cont = 1.0 ± 0.1; TCDD = 1.3 ± 0.2; p = 0.114) fluorescence and increased DAF-2DA fluorescence (siAhR: Cont = 1.00 ± 0.03; TCDD = 0.97 ± 0.03; p = 0.481) (siCYP1A1: Cont = 1.00 ± 0.03; TCDD = 0.92 ± 0

  5. ADSORPTION OF POLYCHLORINATED BIPHENYLS BY SOILS

    Directory of Open Access Journals (Sweden)

    Mihaela Preda

    2010-01-01

    Full Text Available The behavior of polychlorinated biphenyls (PCBs in soil is determined by several factors including adsorption, mobility and degradation. Adsorption, directly or indirectly, influences the other factors. Adsorption process is generally evaluated by using adsorption isotherms representing the relationship between the quantity of substance adsorbed per unit weight and concentration of the substance in solution at equilibrium. They allow determination of the adsorption constant, which is directly proportional to the adsorption of PCBs in soil. PCBs are very insoluble in water, so they tend to accumulate in the lipids. This is the reason why polychlorinated biphenyls are more strongly adsorbed in soils with higher organic matter content. To obtain the adsorption isotherm were used standard solutions of PCB 101with initial concentrations: 0.05, 0.1, 0.5, 1 and 2 g/ml. The adsorption constants were in order: 3072 ml/g for chernozem, 2943 mg/l for chromic luvisol, 998 mg/l for aluviosol and 1443 mg/l for anthrosol. The values of adsorption constants depend on the organic matter and clay content.

  6. Nanoscale zero-valent iron (nZVI) synthesis in a Mg-aminoclay solution exhibits increased stability and reactivity for reductive decontamination

    DEFF Research Database (Denmark)

    Hwang, Yuhoon; Lee, Young-Chul; Mines, Paul D.;

    2014-01-01

    Nanoscale zero-valent iron (nZVI) has often been explored as a reductant for detoxification of pollutants in environmental clean-ups. Despite the large surface area and superior reactivity of nZVI, its limited stability is a major obstacle in applying nZVI for in situ subsurface remediation, e.g....... feasibility, compared to uncoated nZVI, for application in remediation of subsurface contaminations; where high stability and mobility as well as high reactivity for degradation of contaminants is desired....

  7. Oxidation of polychlorinated biphenyls by Pseudomonas sp. strain LB400 and Pseudomonas pseudoalcaligenes KF707.

    OpenAIRE

    Gibson, D T; Cruden, D. L.; Haddock, J D; Zylstra, G J; Brand, J M

    1993-01-01

    Biphenyl-grown cells and cell extracts prepared from biphenyl-grown cells of Pseudomonas sp. strain LB400 oxidize a much wider range of chlorinated biphenyls than do analogous preparations from Pseudomonas pseudoalcaligenes KF707. These results are attributed to differences in the substrate specificity of the biphenyl 2,3-dioxygenases from both organisms.

  8. Serum Reactivity Against Bacterial Pyruvate Dehydrogenase: Increasing the Specificity of Anti-Mitochondrial Antibodies for the Diagnosis of Primary Biliary Cirrhosis

    Directory of Open Access Journals (Sweden)

    Carlo Selmi

    2006-01-01

    Full Text Available Antimitochondrial antibodies (AMA are the serum hallmark of primary biliary cirrhosis (PBC. However, AMA-positivity can be found in non-PBC sera when lower dilutions are used, thus raising issues about the specificity and sensitivity of the test. AMA reacts primarily with the lipoylated domains of pyruvate dehydrogenase-E2 (PDC-E2 which is highly conserved across species, including bacteria. We studied 77 serum samples, including 24 from patients with anti-PDC-E2-positive PBC and 53 controls (16 with autoimmune hepatitis (AIH, 10 with primary sclerosing cholangitis (PSC, and 27 healthy individuals for their reactivities at serial dilutions (1:10, 1:20 and 1:40 against Escherichia coli DH5 alpha lysate overexpressing human PDC-E2 using immunoblotting (IB. A murine anti-human PDC-E2 monoclonal antibody (mAB was used as control. We further studied positive sera using adsorption with a synthetic E. coli peptide sharing similarity with human PDC-E2. Finally, we verified whether a unique buffer for E. coli preparation could reduce non-specific serum reactivity. Results demonstrated that 100% of anti-PDC-E2-positive PBC and up to 38% of control sera at 1:10 dilution recognized E. coli PDC-E2 at IB while dilution tests indicated that the overall potency of PBC reactivity was 100-fold higher compared to controls. In fact, a subgroup (20-38% of non-PBC sera were positive at low titers but lost the reactivity when absorbed with the synthetic E. coli peptide. Finally, our unique buffer reduced the reactivity of non-PBC sera as measured by ELISA. In conclusion, we demonstrated that weak cross-reactivity with E. coli PDC-E2 occurs in non-PBC sera at lower dilutions and that such reactivity is not due to AMA-positivity. The use of a specific buffer might avoid the risk of false positive AMA determinations when E. coli-expressed recombinant antigens are used.

  9. Polychlorinated Biphenyl-77 Induces Adipocyte Differentiation and Proinflammatory Adipokines and Promotes Obesity and Atherosclerosis

    OpenAIRE

    Arsenescu, Violeta; Arsenescu, Razvan I; King, Victoria; Swanson, Hollie; Cassis, Lisa A.

    2008-01-01

    Background Obesity, an inflammatory condition linked to cardiovascular disease, is associated with expansion of adipose tissue. Highly prevalent coplanar polychlorinated biphenyls (PCBs) such as 3,3′,4,4′-tetrachlorobiphenyl (PCB-77) accumulate in adipose tissue because of their lipophilicity and increase with obesity. However, the effects of PCBs on adipocytes, obesity, and obesity-associated cardiovascular disease are unknown. Objectives In this study we examined in vitro and in vivo effect...

  10. Plasma Levels of Polychlorinated Biphenyls, Non-Hodgkin Lymphoma, and Causation

    OpenAIRE

    Kohles, Sean S.; Freeman, Michael D

    2012-01-01

    Polychlorinated biphenyls (PCBs) are synthetic chlorinated hydrocarbons that have extensively polluted the environment and bioaccumulated in the food chain. PCBs have been deemed to be probable carcinogens by the Environmental Protection Agency, and exposure to high levels of PCBs has been consistently linked to increased risk of non-Hodgkin lymphoma (NHL). In the present article we present a forensic epidemiologic evaluation of the causal relationship between NHL and elevated PCB levels via ...

  11. Prenatal Exposure to Polychlorinated Biphenyls and Postnatal Growth: A Structural Analysis

    OpenAIRE

    Lamb, Matthew R.; Taylor, Sylvia; Liu, Xinhua; Wolff, Mary S.; Borrell, Luisa; Matte, Thomas D; Susser, Ezra S.; Factor-Litvak, Pam

    2005-01-01

    Normal endocrine function in utero and early in childhood influences later height and weight attainment. Polychlorinated biphenyls (PCBs) are persistent environmental contaminants with suspected endocrine-disrupting properties. PCBs may mimic or inhibit hormone and endocrine processes based in part on their structural configuration, with non-ortho-substituted PCBs having a coplanar orientation and ortho-substituted PCBs becoming increasingly noncoplanar. Coplanar and noncoplanar PCBs have kno...

  12. Polychlorinated biphenyls and reproductive hormones in female polar bears at Svalbard.

    OpenAIRE

    Haave, Marte; Ropstad, Erik; Derocher, Andrew E; Lie, Elisabeth; Dahl, Ellen; Wiig, Øystein; Skaare, Janneche U; Jenssen, Bjørn Munro

    2003-01-01

    High concentrations of polychlorinated biphenyls (PCBs) in polar bears from Svalbard have increased concern for that population's reproductive health. We examined whether there were associations between the plasma concentrations of PCBs and reproductive hormones [progesterone (P4)] and 17 beta-estradiol (E2)] in free-living female polar bears from Svalbard. Concentrations of P4 depended on reproductive status, and concentrations were lowest in females with offspring--females with cubs and fem...

  13. Stimulatory effects of a microbially dechlorinated polychlorinated biphenyl (PCB) mixture on rat uterine contraction in vitro

    OpenAIRE

    Tsuneta, Taeko; Loch-Caruso, Rita; Quensen, John F.; Boyd, Stephen A.; Hanna, Mona; Grindatti, Carmen

    2008-01-01

    Microbially mediated reductive dechlorination has been advocated as the first part of a two-stage (anaerobic/aerobic) biotreatment process for polychlorinated biphenyls (PCBs) in sediments, and is generally viewed as a detoxication process. However, previous studies suggest that microbial dechlorination increases ability to stimulate uterine contractions compared with the original PCB mixtures. Here, we investigate the composition and uterotonic activity of the commercial PCB mixture Aroclor ...

  14. Effect of Chemical Structure on the Isobaric and Isochoric Fragility in Polychlorinated Biphenyls

    OpenAIRE

    Roland, C. M.; Casalini, R.

    2005-01-01

    Pressure-volume-temperature data, along with dielectric relaxation measurements, are reported for a series of polychlorinated biphenyls (PCB), differing in the number of chlorine atoms on their phenyl rings. Analysis of the results reveals that with increasing chlorine content, the relaxation times of the PCB become governed to a greater degree by density, rho, relative to the effect of temperature, T. This result is consistent with the respective magnitudes of the scaling exponent, gamma, yi...

  15. Sphingobium fuliginis HC3: a novel and robust isolated biphenyl- and polychlorinated biphenyls-degrading bacterium without dead-end intermediates accumulation.

    Directory of Open Access Journals (Sweden)

    Jinxing Hu

    Full Text Available Biphenyl and polychlorinated biphenyls (PCBs are typical environmental pollutants. However, these pollutants are hard to be totally mineralized by environmental microorganisms. One reason for this is the accumulation of dead-end intermediates during biphenyl and PCBs biodegradation, especially benzoate and chlorobenzoates (CBAs. Until now, only a few microorganisms have been reported to have the ability to completely mineralize biphenyl and PCBs. In this research, a novel bacterium HC3, which could degrade biphenyl and PCBs without dead-end intermediates accumulation, was isolated from PCBs-contaminated soil and identified as Sphingobium fuliginis. Benzoate and 3-chlorobenzoate (3-CBA transformed from biphenyl and 3-chlorobiphenyl (3-CB could be rapidly degraded by HC3. This strain has strong degradation ability of biphenyl, lower chlorinated (mono-, di- and tri- PCBs as well as mono-CBAs, and the biphenyl/PCBs catabolic genes of HC3 are cloned on its plasmid. It could degrade 80.7% of 100 mg L -1 biphenyl within 24 h and its biphenyl degradation ability could be enhanced by adding readily available carbon sources such as tryptone and yeast extract. As far as we know, HC3 is the first reported that can degrade biphenyl and 3-CB without accumulation of benzoate and 3-CBA in the genus Sphingobium, which indicates the bacterium has the potential to totally mineralize biphenyl/PCBs and might be a good candidate for restoring biphenyl/PCBs-polluted environments.

  16. Occupational exposure to polychlorinated biphenyls in electrical workers. I. Environmental and blood polychlorinated biphenyls concentrations.

    OpenAIRE

    Maroni, M; Colombi, A.; Cantoni, S; Ferioli, E; Foa, V

    1981-01-01

    Industrial exposure to polychlorinated biphenyls (PCBs) and internal dose were investigated in 80 worker exposed for many years to PCB mixtures with a 42% chlorine content (Pyralene 3010 and Apirolio). PCBs were determined by liquid gas chromatography on samples taken from workroom air, workroom surfaces and tools, the palms of the hand, and the blood of the workers. In the workroom air samples, PCB concentrations ranged from 48 to 275 micrograms/m3. All tested surfaces and tools were heavily...

  17. Synthesis, characterization and reactivity of some lanthanide organometallics

    International Nuclear Information System (INIS)

    Organo lanthanides with reactive metal-carbon bonds are obtained by direct synthesis of the metal (powder) and a hydrocarbon in ether medium, like with alkali metals. Two types of synthesis are envisaged: formation of covalent bonds by opening cycles, only biphenylene is reactive enough in regard to ytterbium and samarium, these organometallic compounds can also be prepared by the classical way, i.e. reaction of 2.2'-dilithio biphenyl on rare earth halogenides and coupling of 6.6-dimethylfulvene leading to dicyclopentadienyl compounds with Sm and Yb. The reactivity of these complexes is studied by catalysis of ethylene polymerization

  18. Increased generation of intracellular reactive oxygen species initiates selective cytotoxicity against the MCF-7 cell line resultant from redox active combination therapy using copper-thiosemicarbazone complexes.

    Science.gov (United States)

    Akladios, Fady N; Andrew, Scott D; Parkinson, Christopher J

    2016-06-01

    The combination of cytotoxic copper-thiosemicarbazone complexes with phenoxazines results in an up to 50-fold enhancement in the cytotoxic potential of the thiosemicarbazone against the MCF-7 human breast adenocarcinoma cell line over the effect attributable to drug additivity-allowing minimization of the more toxic copper-thiosemicarbazone component of the therapy. The combination of a benzophenoxazine with all classes of copper complex examined in this study proved more effective than combinations of the copper complexes with related isoelectronic azines. The combination approach results in rapid elevation of intracellular reactive oxygen levels followed by apoptotic cell death. Normal fibroblasts representative of non-cancerous cells (MRC-5) did not display a similar elevation of reactive oxygen levels when exposed to similar drug levels. The minimization of the copper-thiosemicarbazone component of the therapy results in an enhanced safety profile against normal fibroblasts. PMID:26951232

  19. Hyperglycemia Enhances IGF-I–Stimulated Src Activation via Increasing Nox4-Derived Reactive Oxygen Species in a PKCζ-Dependent Manner in Vascular Smooth Muscle Cells

    OpenAIRE

    Xi, Gang; Shen, Xinchun; Maile, Laura A.; Wai, Christine; Gollahon, Katherine; Clemmons, David R.

    2011-01-01

    IGF-I–stimulated sarcoma viral oncogene (Src) activation during hyperglycemia is required for propagating downstream signaling. The aim of the current study was to determine the mechanism by which hyperglycemia enhances IGF-I–stimulated Src activation and the role of NADPH oxidase 4 (Nox4) and protein kinase C ζ (PKCζ) in mediating this response in vascular smooth muscle cells (VSMCs). Nox4 expression was analyzed in VSMCs exposed to hyperglycemia. The role of Nox4-derived reactive oxygen spe...

  20. Sphingobium fuliginis HC3: A Novel and Robust Isolated Biphenyl- and Polychlorinated Biphenyls-Degrading Bacterium without Dead-End Intermediates Accumulation

    OpenAIRE

    Hu, Jinxing; Qian, Mingrong; Zhang, Qian; Cui, Jinglan; Yu, Chunna; Su, Xiaomei; Shen, Chaofeng; Hashmi, Muhammad Z.; Shi, Jiyan

    2015-01-01

    Biphenyl and polychlorinated biphenyls (PCBs) are typical environmental pollutants. However, these pollutants are hard to be totally mineralized by environmental microorganisms. One reason for this is the accumulation of dead-end intermediates during biphenyl and PCBs biodegradation, especially benzoate and chlorobenzoates (CBAs). Until now, only a few microorganisms have been reported to have the ability to completely mineralize biphenyl and PCBs. In this research, a novel bacterium HC3, whi...

  1. Spatial gradients of polychlorinated biphenyls (PCBs) and organochlorine pesticides

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spatial gradients of polychlorinated biphenyls (PCBs) and organochlorine pesticides were examined in the young-of-the-year (YOY) blue多sh collected in the vicinity...

  2. Bioaccumulation dynamics of polychlorinated biphenyls (PCBs) and organochlorine pesticides

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bioaccumulation dynamics of polychlorinated biphenyls (PCBs) and organochlorine pesticides was examined in young-of-the-year bluefish from seven sub-estuaries of...

  3. Effective inhibition of hydroxyl radicals by hydroxylated biphenyl compounds.

    Science.gov (United States)

    Taira, J; Ikemoto, T; Mimura, K; Hagi, A; Murakami, A; Makino, K

    1993-01-01

    In aqueous media, approximate rate constants for the reactions between hydroxyl radicals (.OH) and biphenyl compounds such as dehydrodieugenol, magnolol, honokiol, dehydrodidihydroeugenol, dehydrodivanillyl alcohol, and dehydrodicreosol were estimated by competition reactions for .OH between these biphenyls and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). By measuring the decrease in the height of the EPR signals of the .OH spin adduct, rate constants in the order of 10(9) to 10(10) M were measured. PMID:8282234

  4. NUCLEOTIDE SEQUENCING AND TRANSCRIPTIONAL MAPPING OF THE GENES ENCODING BIPHENYL DIOXYGENASE, A MULTICOM- PONENT POLYCHLORINATED-BIPHENYL-DEGRADING ENZYME IN PSEUDOMONAS STRAIN LB400

    Science.gov (United States)

    The DNA region encoding biphenyl dioxygenase, the first enzyme in the biphenyl-polychlorinated biphenyl degradation pathway of Pseudomonas species strain LB400, was sequenced. Six open reading frames were identified, four of which are homologous to the components of toluene dioxy...

  5. Cotton metallothionein GhMT3a, a reactive oxygen species scavenger, increased tolerance against abiotic stress in transgenic tobacco and yeast

    OpenAIRE

    Xue, Tongtong; Li, Xinzheng; Zhu, Wei; Wu, Changai; Yang, Guodong; Zheng, Chengchao

    2008-01-01

    A cDNA clone encoding a 64-amino acid type 3 metallothionein protein, designated GhMT3a, was isolated from cotton (Gossypium hirsutum) by cDNA library screening. Northern blot analysis indicated that mRNA accumulation of GhMT3a was up-regulated not only by high salinity, drought, and low temperature stresses, but also by heavy metal ions, abscisic acid (ABA), ethylene, and reactive oxygen species (ROS) in cotton seedlings. Transgenic tobacco (Nicotiana tabacum) plants overexpressing GhMT3a sh...

  6. ENANTIOMER SEPARATION OF POLYCHLORINATED BIPHENYL ATROPISOMERS AND POLYCHLORINATED BIPHENYL RETENTION BEHAVIOR ON MODIFIED CYCLODEXTRIN CAPILLARY GAS CHROMATOGRAPHY COLUMNS

    Science.gov (United States)

    Seven commercially-available chiral capillary gas chromatography columns containing modified cyclodextrins were evaluated for their ability to separate enantiomers of the 19 stable chiral polychlorinated biphenyl (PCB) atropisomers, and for their ability to separate these enantio...

  7. Antiproliferative and pro-apoptotic activity of eugenol-related biphenyls on malignant melanoma cells

    Directory of Open Access Journals (Sweden)

    Dettori Maria

    2007-01-01

    Full Text Available Abstract Background Malignant melanoma is one of the most aggressive skin cancer and chemotherapeutic agents currently in use are still unsatisfactory. Prevention and early diagnosis are the only effective tools against this tumour whose incidence and mortality rates are highly increased during the last decades in fair skin populations. Therefore the search for novel therapeutic approaches is warranted. Aim of this work was to identify and test new compounds with antiproliferative and cytotoxic activity on melanoma cells. We tested eugenol together with six natural and synthetic eugenol-related compounds for their capability to inhibit cell growth on primary melanoma cell lines established from patients' tissue samples. Results Eugenol and isoeugenol monomers and their respective O-methylated forms did not show to inhibit melanoma cells proliferation. Conversely, the dimeric forms (biphenyls showed some antiproliferative activity which was mild for dehydrodieugenol, higher for its O,O'-methylated form (O,O'-dimethyl-dehydrodieugenol, and markedly pronounced for the racemic mixture of the brominated biphenyl (6,6'-dibromo-dehydrodieugenol (S7, being its enantiomeric form (S the most effective compared to the other compounds. Such activity resulted to be selective against tumour cells, without affecting cultured normal human skin fibroblasts. Dose and time dependence curves have been obtained for the enantiomeric form S7-(S. Then IC50 and minimal effective doses and times have been established for the melanoma cell lines tested. TUNEL and phosphatidylserine exposure assays demonstrated the occurrence of apoptotic events associated with the antiproliferative activity of S7-(S. Cytotoxic activity and apoptosis induced by treating melanoma cells with eugenol-related biphenyls was partially dependent by caspase activation. Conclusion Our findings demonstrate that the eugenol related biphenyl (S-6,6'-dibromo-dehydrodieugenol elicits specific

  8. Structural characterization of Pandoraea pnomenusa B-356 biphenyl dioxygenase reveals features of potent polychlorinated biphenyl-degrading enzymes.

    Directory of Open Access Journals (Sweden)

    Christopher L Colbert

    Full Text Available The oxidative degradation of biphenyl and polychlorinated biphenyls (PCBs is initiated in Pandoraea pnomenusa B-356 by biphenyl dioxygenase (BPDO(B356. BPDO(B356, a heterohexameric (αβ(3 Rieske oxygenase (RO, catalyzes the insertion of dioxygen with stereo- and regioselectivity at the 2,3-carbons of biphenyl, and can transform a broad spectrum of PCB congeners. Here we present the X-ray crystal structures of BPDO(B356 with and without its substrate biphenyl 1.6-Å resolution for both structures. In both cases, the Fe(II has five ligands in a square pyramidal configuration: H233 Nε2, H239 Nε2, D386 Oδ1 and Oδ2, and a single water molecule. Analysis of the active sites of BPDO(B356 and related ROs revealed structural features that likely contribute to the superior PCB-degrading ability of certain BPDOs. First, the active site cavity readily accommodates biphenyl with minimal conformational rearrangement. Second, M231 was predicted to sterically interfere with binding of some PCBs, and substitution of this residue yielded variants that transform 2,2'-dichlorobiphenyl more effectively. Third, in addition to the volume and shape of the active site, residues at the active site entrance also apparently influence substrate preference. Finally, comparison of the conformation of the active site entrance loop among ROs provides a basis for a structure-based classification consistent with a phylogeny derived from amino acid sequence alignments.

  9. Polychlorinated biphenyls and their interaction with the environment

    Energy Technology Data Exchange (ETDEWEB)

    Dickerson, K.S.; Korte, N.E.

    1994-05-01

    This document is a review of the existing technical literature regarding the physical and biological properties of polychlorinated biphenyls (PCBs) and their interaction with the environment. It is intended to be used when evaluating PCB-contaminated soil and the effects of specific environmental conditions on PCB degradation. PCBs are a class of chlorinated aromatic compounds with 209 possible structural arrangements. The composition of PCBs in the environment changes over time due to various physiochemical and biological properties and processes: vapor pressure, solubility, octanol-water partitioning, adsorption, and biodegradation. As the number of chlorine atoms increases, both vapor pressure and water solubility decrease, while adsorption and the octanol-water partitioning coefficient increase. Dechlorination of PCBs occurs primarily through aerobic and anaerobic microbial degradation. Aerobic bacteria preferentially dechlorinate less-chlorinated PCBs, while anaerobic bacteria preferentially dechlorinate more highly chlorinated PCBs. The less-chlorinated PCB congeners are less persistent in the environment due to volatilization, solubility, and aerobic biodegradation, while the more-chlorinated PCBs are more persistent in the environment due to adsorption. The composition of an original PCB mixture in the environment can be expected to change due to a combination of processes described above. Any attempt to determine the source of PCBs or Aroclors identified in an environment sample must be approached with caution to avoid inaccurate conclusions.

  10. Increased ventricular ectopic activity in relation to C-reactive protein, and NT-pro-brain natriuretic peptide in subjects with no apparent heart disease

    DEFF Research Database (Denmark)

    Sajadieh, A; Nielsen, OW; Rasmussen, Verner;

    2006-01-01

    BACKGROUND: Subjects with frequent ventricular premature complexes (VPC) and no apparent heart disease make a heterogenic group with regard to prognosis. Some biomarkers have recently proved useful in risk stratification in different heart diseases. We examined prognostic impact of NT-Pro-brain n......BACKGROUND: Subjects with frequent ventricular premature complexes (VPC) and no apparent heart disease make a heterogenic group with regard to prognosis. Some biomarkers have recently proved useful in risk stratification in different heart diseases. We examined prognostic impact of NT......-Pro-brain natriuretic peptide (NT-Pro BNP), and C-reactive protein (CRP) in relation to frequent VPC in subjects with no apparent heart disease. METHODS: Six hundred seventy-eight healthy subjects between 55 and 75 years of age with no history of cardiovascular disease were included in the study. All were tested...

  11. New technologies for PCB [polychlorinated biphenyl] decontamination

    International Nuclear Information System (INIS)

    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

  12. Options for PCB (polychlorinated biphenyls) analysis reviewed

    Energy Technology Data Exchange (ETDEWEB)

    Finch, S

    1990-04-01

    Types of polychlorinated biphenyl (PCB) analysis can be divided into two categories: specific and non-specific methods. Specific methods include gas chromatogrphy and mass spectrometry, which test for PCB molecules in particular. Non-specific methods identify classes of compounds, such as chlorinated hydrocarbons, to which PCBs belong. These non-specific methods include Chlor-N-Oil PCB screening kits, x-ray fluorescence spectroscopy, and microcoulemetric titration. In general, PCB-specific methods are more accurate than non-specific methods, but are also more expensive, more lengthy to run, and less portable. Non-specific methods test for the presence of chlorine in the sample, and as a result other chlorinated componds will cause false positive results, however false negative results should not occur. Although false positive results can cause unnecessary secondary testing, they can be very economical when used on samples such as transformer oil, which contains few sources of chlorine other than PCB. Used crank case and cutting oils almost always give false positive results with non-specific tests. Details are presented of a new non-specific test, the L2000 PCB Analyzer, which can be used on transformer oil, soil samples, and for testing of total organic chlorine levels in waste oils. 1 fig.

  13. Effects of polychlorinated biphenyls and lipemia on serum analytes

    Energy Technology Data Exchange (ETDEWEB)

    Steinberg, K.K.; Freni-Titulaer, L.W.J.; Rogers, T.N.; Burse, V.W.; Mueller, P.W.; Stehr, P.A.; Miller, D.T.; Steele, G.

    1986-01-01

    Twelve serum analytes (triglycerides, cholesterol, total and conjugated bilirubin, high-density-lipoprotein cholesterol (HDL-C) alkaline phosphatase (AP), gammaglutamyl transferase (GGT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), ..beta..-glucoronidase (..beta..-glu), alanine aminopeptidase (AAP), and 5'-nucleotidase (5'nuc)) were measured to investigate their correlation with exposure to polychlorinated biphenyls (PCBs) and 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT). The relationship between serum lipids, lipophilic toxicants, and the analytes was also evaluated. The ..beta..-glue, 5'nuc, triglycerides, cholesterol, and total bilirubin correlated positively and significantly with log concentrations of serum total PCBs and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), a metabolite of DDT. The more highly chlorinated PCBs had significant, positive correlations with several serum analytes, but the less chlorinated PCBs correlated significantly and negatively only with HDL-cholesterol. Triglyercide- and cholesterol-rich lipoproteins were added to serum to determine the effects of lipids on these assays. Several were spuriously elevated. AP and ..beta..-glu were not affected by lipoprotein addition with the methods used in this study. AAP was increased significantly only at triglyceide concentrations exceeding 400 mg/dl.

  14. Polychlorinated Biphenyls Water Pollution along the River Nile, Egypt

    Directory of Open Access Journals (Sweden)

    Ayman Mohamed Megahed

    2015-01-01

    Full Text Available Ten polychlorinated biphenyl (PCB congeners were determined in water samples collected along the River Nile using gas chromatography-electron capture detector (GC-ECD. PCB concentrations ranged from 14 to 20 μg/L, which were higher than those reported in previous studies, indicating serious PCB pollution in the River Nile. PCB congener profiles varied depending on the sampling sties. PCB-138 was the predominant congener accounting for more than 18% of total PCBs. The composition of PCB congeners in the water revealed that highly chlorinated PCB technical mixtures such as Aroclor 1254 was the main PCB production historically used in Egypt. An increasing trend in PCB levels from the upper stream to the Nile estuaries was observed. The calculated flux of PCBs indicated that 6.8 tons of PCBs is dumped into the Mediterranean Sea each year from the River Nile. The hazard quotients and carcinogenic risk caused by PCB pollution in the River Nile were above the acceptable level indicating that PCBs in the River Nile water pose adverse health effects for all age groups. Our findings revealed that PCBs possess a serious risk to the Egyptian population that depends mainly on the River Nile as a source of water. Thus, stricter legislation and regulatory controls should be applied to reduce the risk of PCBs in Egypt.

  15. Reactive Arthritis

    Directory of Open Access Journals (Sweden)

    Eren Erken

    2013-06-01

    Full Text Available Reactive arthritis is an acute, sterile, non-suppurative and inflammatory arthropaty which has occured as a result of an infectious processes, mostly after gastrointestinal and genitourinary tract infections. Reiter syndrome is a frequent type of reactive arthritis. Both reactive arthritis and Reiter syndrome belong to the group of seronegative spondyloarthropathies, associated with HLA-B27 positivity and characterized by ongoing inflammation after an infectious episode. The classical triad of Reiter syndrome is defined as arthritis, conjuctivitis and urethritis and is seen only in one third of patients with Reiter syndrome. Recently, seronegative asymmetric arthritis and typical extraarticular involvement are thought to be adequate for the diagnosis. However, there is no established criteria for the diagnosis of reactive arthritis and the number of randomized and controlled studies about the therapy is not enough. [Archives Medical Review Journal 2013; 22(3.000: 283-299

  16. Reactive Safety

    OpenAIRE

    Rüdiger Ehlers; Bernd Finkbeiner

    2011-01-01

    The distinction between safety and liveness properties is a fundamental classification with immediate implications on the feasibility and complexity of various monitoring, model checking, and synthesis problems. In this paper, we revisit the notion of safety for reactive systems, i.e., for systems whose behavior is characterized by the interplay of uncontrolled environment inputs and controlled system outputs. We show that reactive safety is a strictly larger class of properties than standard...

  17. Reactivity measurements

    International Nuclear Information System (INIS)

    Digital reactivity meter, realized as an off-line Fortran program, the input to which is a record of 500 consecutive values of n(tsub(i)) obtained by on-line program on CDC 1700 from the linear power channel of the TRIGA reactor, has been tested at low powers at which the reactor fuel temperature feedback reactivity is negligible. Calibration of the meter by the regulating rod, the reactivity of which has been determined by the assymptotic reactor period, shows that the absolute error is below 1,6% for reactivities up to 1 $. The accuracy of the reactivity meter is proportional to the square of the product of the sampling interval and the period at which the neutron density changes. So the relative error of the reactivity remains at all operational states below 0.2% at 1 second sampling intervals and even at 3 seconds sampling it does not rises above 2.0%. The meter is useful for measurements of control rod drops into the reactor at sampling intervals of 0.1 sec. The meter sensitivity is 0.5 c/s at 1 sec sampling

  18. 75 FR 34076 - Polychlorinated Biphenyls (PCBs); Reassessment of Use Authorizations; Extension of Comment Period...

    Science.gov (United States)

    2010-06-16

    ... AGENCY 40 CFR Part 761 RIN 2070-AJ38 Polychlorinated Biphenyls (PCBs); Reassessment of Use Authorizations..., Hazardous substances, Labeling, Polychlorinated biphenyls (PCBs), Reporting and recordkeeping requirements..., 2010, concerning the reassessment of the use authorizations for PCBs. This document extends the...

  19. A diet rich in fat and poor in dietary fiber increases the in vitro formation of reactive oxygen species in human feces.

    Science.gov (United States)

    Erhardt, J G; Lim, S S; Bode, J C; Bode, C

    1997-05-01

    Production of reactive oxygen species in the lumen of the colon, a process that is influenced by nutritional factors, may be important in the etiology of colorectal cancer. Because research on humans in support of this hypothesis is lacking, the objective of this study was to measure the effect of different dietary compositions on the in vitro oxygen radical production in human feces. Over a period of 12 d, seven healthy subjects received a diet rich in fat (50%) and meat and poor in dietary fiber. After a period of 1 wk, they received a vegetarian diet poor in fat (20%) and rich in dietary fiber. At the end of each study period, feces were collected and analyzed for in vitro oxygen radical production with dimethylsulfoxide as the free radical scavenger. The mean hydroxyl radical production was 13 times greater in feces of subjects when they consumed the diet rich in fat and poor in dietary fiber [52.7 +/- 29.5 micromol/(g feces x h)] than when they consumed the diet poor in fat and rich in dietary fiber [3.9 +/- 3.9 micromol/(g feces x h); P colorectal cancer. PMID:9164990

  20. Adaptation mechanisms of bacteria during the degradation of polychlorinated biphenyls in the presence of natural and synthetic terpenes as potential degradation inducers

    Energy Technology Data Exchange (ETDEWEB)

    Zoradova-Murinova, Slavomira; Dudasova, Hana; Lukacova, Lucia; Certik, Milan; Dercova, Katarina [Slovak Univ. of Technology, Bratislava (Slovakia). Inst. of Biotechnology and Food Science; Silharova, Katarina; Vrana, Branislav [Water Research Institute, Bratislava (Slovakia)

    2012-06-15

    In this study, we examined the effect of polychlorinated biphenyls (PCBs) in the presence of natural and synthetic terpenes and biphenyl on biomass production, lipid accumulation, and membrane adaptation mechanisms of two PCB-degrading bacterial strains Pseudomonas stutzeri and Burkholderia xenovorans LB400. According to the results obtained, it could be concluded that natural terpenes, mainly those contained in ivy leaves and pine needles, decreased adaptation responses induced by PCBs in these strains. The adaptation processes under investigation included growth inhibition, lipid accumulation, composition of fatty acids, cis/trans isomerization, and membrane saturation. Growth inhibition effect decreased upon addition of these natural compounds to the medium. The amount of unsaturated fatty acids that can lead to elevated membrane fluidity increased in both strains after the addition of the two natural terpene sources. The cells adaptation changes were more prominent in the presence of carvone, limonene, and biphenyl than in the presence of natural terpenes, as indicated by growth inhibition, lipid accumulation, and cis/trans isomerization. Addition of biphenyl and carvone simultaneously with PCBs increased the trans/cis ratio of fatty acids in membrane fractions probably as a result of fluidizing effects of PCBs. This stimulation is more pronounced in the presence of PCBs as a sole carbon source. This suggests that PCBs alone have a stronger effect on bacterial membrane adaptation mechanisms than when added together with biphenyl or natural or synthetic terpenes. (orig.)

  1. Complete Reductive Dehalogenation of Brominated Biphenyls by Anaerobic Microorganisms in Sediment

    OpenAIRE

    Bedard, Donna L.; Van Dort, Heidi M.

    1998-01-01

    We sought to determine whether microorganisms from the polychlorinated biphenyl (PCB)-contaminated sediment in Woods Pond (Lenox, Mass.) could dehalogenate brominated biphenyls. The PCB dechlorination specificities for the microorganisms in this sediment have been well characterized. This allowed us to compare the dehalogenation specificities for brominated biphenyls and chlorinated biphenyls within a single sediment. Anaerobic sediment microcosms were incubated separately at 25°C with 16 dif...

  2. Biphenyl 4-Hydroxylases Involved in Aucuparin Biosynthesis in Rowan and Apple Are Cytochrome P450 736A Proteins.

    Science.gov (United States)

    Sircar, Debabrata; Gaid, Mariam M; Chizzali, Cornelia; Reckwell, Dennis; Kaufholdt, David; Beuerle, Till; Broggini, Giovanni A L; Flachowsky, Henryk; Liu, Benye; Hänsch, Robert; Beerhues, Ludger

    2015-06-01

    Upon pathogen attack, fruit trees such as apple (Malus spp.) and pear (Pyrus spp.) accumulate biphenyl and dibenzofuran phytoalexins, with aucuparin as a major biphenyl compound. 4-Hydroxylation of the biphenyl scaffold, formed by biphenyl synthase (BIS), is catalyzed by a cytochrome P450 (CYP). The biphenyl 4-hydroxylase (B4H) coding sequence of rowan (Sorbus aucuparia) was isolated and functionally expressed in yeast (Saccharomyces cerevisiae). SaB4H was named CYP736A107. No catalytic function of CYP736 was known previously. SaB4H exhibited absolute specificity for 3-hydroxy-5-methoxybiphenyl. In rowan cell cultures treated with elicitor from the scab fungus, transient increases in the SaB4H, SaBIS, and phenylalanine ammonia lyase transcript levels preceded phytoalexin accumulation. Transient expression of a carboxyl-terminal reporter gene construct directed SaB4H to the endoplasmic reticulum. A construct lacking the amino-terminal leader and transmembrane domain caused cytoplasmic localization. Functional B4H coding sequences were also isolated from two apple (Malus × domestica) cultivars. The MdB4Hs were named CYP736A163. When stems of cv Golden Delicious were infected with the fire blight bacterium, highest MdB4H transcript levels were observed in the transition zone. In a phylogenetic tree, the three B4Hs were closest to coniferaldehyde 5-hydroxylases involved in lignin biosynthesis, suggesting a common ancestor. Coniferaldehyde and related compounds were not converted by SaB4H. PMID:25862456

  3. Estrogenicity of selected biphenyls evaluated using a recombinant yeast assay

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, T.W.; Kraut, D.H.; Sayler, G.S.; Layton, A.C. [Univ. of Tennessee, Knoxville, TN (United States)

    1998-09-01

    The estrogenic activity of biphenyl and 4-hydroxylated derivatives with varied levels of chloro- and/or hydroxyl substitution was measured in a Saccharomyces cerevisiae-based lac-Z ({beta}-galactosidase) reporter assay, {beta}-Galactosidase activity was compared with competitive binding to soluble mouse uterine estrogen receptor protein. The comparison of relative potency for biphenyls hydroxylated on one ring and chlorinated on the other ring (n = 5) revealed excellent correlation between the two systems (r{sup 2} = 0.995). However, estrogenicities of biphenyls hydroxylated and chlorinated on the same ring were not in agreement. Although weak ligand binding was demonstrated for these compounds, {beta}-galactosidase activity was not observed. Rather, these compounds were shown to be cytotoxic to yeast. The results of this study further support the hypothesis that both an unhindered phenolic ring and molecular symmetry are structural features associated with estrogenicity.

  4. 75 FR 4759 - Polychlorinated Biphenyls: Manufacturing (Import) Exemption for Veolia ES Technical Solutions, LLC

    Science.gov (United States)

    2010-01-29

    ... commerce of polychlorinated biphenyls (PCBs). Under TSCA section 3(7), ``manufacture'' is defined to... AGENCY 40 CFR Part 761 RIN 2050-AG42 Polychlorinated Biphenyls: Manufacturing (Import) Exemption for...'s request in the proposed rule, Polychlorinated Biphenyls: Manufacturing (Import) Exemption...

  5. OXIDATION OF POLYCHLORINATED BIPHENYLS BY PSEUDOMONAS SP. STRAIN LB400 AND PSEUDOMONAS PSEUDOALCALIGENES KF707

    Science.gov (United States)

    Biphenyl-grown cells and cell extracts prepared from biphenyl-grown cells of Pseudomonas sp. strain LB400 oxidize a much wider range of chlorinated biphenyls than do analogous preparations from Pseudomonas pseudoalcaligenes KF707. These results are attributed to differences in th...

  6. OXIDATION OF BIPHENYL BY A MULTICOMPONENT ENZYME SYSTEM FROM PSEUDOMONAS SP. STRAIN LB400

    Science.gov (United States)

    Pseudomonas sp. strain LB400 grows on biphenyl as the sole carbon and energy source. This organism also cooxidizes several chlorinated biphenyl congeners. Biphenyl dioxygenase activity in cell extract required addition of NAD(P)H as an electron donor for the conversion of bipheny...

  7. Exposure Monitoring and Risk Assessment of Biphenyl in the Workplace

    Directory of Open Access Journals (Sweden)

    Hyeon-Yeong Kim

    2015-05-01

    Full Text Available This study was performed to assess exposure to and the risk caused by biphenyl in the workplace. Biphenyl is widely used as a heat transfer medium and as an emulsifier and polish in industry. Vapor or high levels of dust inhalation and dermal exposure to biphenyl can cause eye inflammation, irritation of respiratory organs, and permanent lesions in the liver and nervous system. In this study, the workplace environment concentrations were assessed as central tendency exposure and reasonable maximum exposure and were shown to be 0.03 and 0.12 mg/m3, respectively. In addition, the carcinogenic risk of biphenyl as determined by risk assessment was 0.14 × 10−4 (central tendency exposure and 0.56 × 10−4 (reasonable maximum exposure, which is below the acceptable risk value of 1.0 × 10−4. Furthermore, the central tendency exposure and reasonable maximum exposure hazard quotients were 0.01 and 0.06 for oral toxicity, 0.05 and 0.23 for inhalation toxicity, and 0.08 and 0.39 for reproduction toxicity, respectively, which are all lower than the acceptable hazard quotient of 1.0. Therefore, exposure to biphenyl was found to be safe in current workplace environments. Because occupational exposure limits are based on socioeconomic assessment, they are generally higher than true values seen in toxicity experiments. Based on the results of exposure monitoring of biphenyl, the current occupational exposure limits in Korea could be reviewed.

  8. Opposing effects on glutathione and reactive oxygen metabolites of sex, habitat, and spring date, but no effect of increased breeding density in great tits (Parus major).

    Science.gov (United States)

    Isaksson, Caroline

    2013-08-01

    Oxidative stress (i.e., more oxidants than antioxidants) has been proposed as a proximate currency in life-history trade-offs, which if studied in an ecological setting allow a more realistic perspective on the origin and evolution of trade-offs. Therefore, the aim here was to investigate the impact of ecological and individual factors for variation in markers of oxidative stress using both experimental and correlational data. Total glutathione (tGSH), oxidized glutathione (GSSG), plasma antioxidant capacity (OXY), and plasma-reactive oxygen metabolites (ROM) were measured in more than 700 breeding great tits (Parus major). The main results revealed a pronounced sex difference, with females having lower ROM and OXY, but higher tGSH compared with males. In addition, birds breeding in the evergreen areas had higher tGSH compared with those in the deciduous habitat, but the experimentally manipulated breeding density had no significant effect on any of the redox markers. Independent of the sex differences, the larger the reproductive investment the lower the ROM of both males and females. Taken together, the extracellular markers - ROM and OXY - revealed similar results and were highly correlated. Interestingly, the direction of their effects was in the opposite direction to the endogenously synthesized tGSH and GSSG. This highlights the need to combine extracellular markers with endogenously synthesized antioxidants to understand its implications for the origin and evolution of trade-offs in an ecological setting. Oxidative stress has been proposed as a proximate currency in life-history trade-offs, which if studied in an ecological setting allow a more realistic perspective on the origin and evolution of trade-offs. Here multiple markers of oxidative stress were analysed in wild great tits. The results reveal that the endogenously synthesized antioxidant glutathione and markers of plasma oxidative stress are affected in opposing directions with regard to sex

  9. Anaerobic degradation of Polychlorinated Biphenyls (PCBs) and Polychlorinated Biphenyls Ethers (PBDEs), and microbial community dynamics of electronic waste-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Song, Mengke [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Luo, Chunling, E-mail: clluo@gig.ac.cn [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Li, Fangbai [Guangdong Institute of Eco-environmental and Soil Sciences, Guangzhou 510650 (China); Jiang, Longfei [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Wang, Yan [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhang, Dayi [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Zhang, Gan [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2015-01-01

    Environmental contamination caused by electronic waste (e-waste) recycling is attracting increasing attention worldwide because of the threats posed to ecosystems and human safety. In the present study, we investigated the feasibility of in situ bioremediation of e-waste-contaminated soils. We found that, in the presence of lactate as an electron donor, higher halogenated congeners were converted to lower congeners via anaerobic halorespiration using ferrous ions in contaminated soil. The 16S rRNA gene sequences of terminal restriction fragments indicated that the three dominant strains were closely related to known dissimilatory iron-reducing bacteria (DIRB) and those able to perform dehalogenation upon respiration. The functional species performed the activities of ferrous oxidation to ferric ions and further ferrous reduction for dehalogenation. The present study links iron cycling to degradation of halogenated materials in natural e-waste-contaminated soil, and highlights the synergistic roles of soil bacteria and ferrous/ferric ion cycling in the dehalogenation of polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs). - Highlights: • The biodegradation PCBs and PBDEs in e-waste contaminated soils was studied. • DIRB and arylhalorespiring bacteria were responsive to dehalogenation respiration. • Soil bacteria and Fe ion cycling play synergistic roles in dehalogenation.

  10. Anaerobic degradation of Polychlorinated Biphenyls (PCBs) and Polychlorinated Biphenyls Ethers (PBDEs), and microbial community dynamics of electronic waste-contaminated soil

    International Nuclear Information System (INIS)

    Environmental contamination caused by electronic waste (e-waste) recycling is attracting increasing attention worldwide because of the threats posed to ecosystems and human safety. In the present study, we investigated the feasibility of in situ bioremediation of e-waste-contaminated soils. We found that, in the presence of lactate as an electron donor, higher halogenated congeners were converted to lower congeners via anaerobic halorespiration using ferrous ions in contaminated soil. The 16S rRNA gene sequences of terminal restriction fragments indicated that the three dominant strains were closely related to known dissimilatory iron-reducing bacteria (DIRB) and those able to perform dehalogenation upon respiration. The functional species performed the activities of ferrous oxidation to ferric ions and further ferrous reduction for dehalogenation. The present study links iron cycling to degradation of halogenated materials in natural e-waste-contaminated soil, and highlights the synergistic roles of soil bacteria and ferrous/ferric ion cycling in the dehalogenation of polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs). - Highlights: • The biodegradation PCBs and PBDEs in e-waste contaminated soils was studied. • DIRB and arylhalorespiring bacteria were responsive to dehalogenation respiration. • Soil bacteria and Fe ion cycling play synergistic roles in dehalogenation

  11. Reactive arthritis.

    Science.gov (United States)

    Keat, A

    1999-01-01

    Reactive arthritis is one of the spondyloarthropathy family of clinical syndromes. The clinical features are those shared by other members of the spondyloarthritis family, though it is distinguished by a clear relationship with a precipitating infection. Susceptibility to reactive arthritis is closely linked with the class 1 HLA allele B27; it is likely that all sub-types pre-dispose to this condition. The link between HLA B27 and infection is mirrored by the development of arthritis in HLA B27-transgenic rats. In this model, arthritis does not develop in animals maintained in a germ-free environment. Infections of the gastrointestinal, genitourinary and respiratory tract appear to provoke reactive arthritis and a wide range of pathogens has now been implicated. Although mechanistic parallels may exist, reactive arthritis is distinguished from Lyme disease, rheumatic fever and Whipple's disease by virtue of the distinct clinical features and the link with HLA B27. As in these conditions both antigens and DNA of several micro-organisms have been detected in joint material from patients with reactive arthritis. The role of such disseminated microbial elements in the provocation or maintenance of arthritis remains unclear. HLA B27-restricted T-cell responses to microbial antigens have been demonstrated and these may be important in disease pathogenesis. The importance of dissemination of bacteria from sites of mucosal infection and their deposition in joints has yet to be fully understood. The role of antibiotic therapy in the treatment of reactive arthritis is being explored; in some circumstances, both the anti-inflammatory and anti-microbial effects of certain antibiotics appear to be valuable. The term reactive arthritis should be seen as a transitory one, reflecting a concept which may itself be on the verge of replacement, as our understanding of the condition develops. Nevertheless it appropriately describes arthritis that is associated with demonstrable

  12. Population Dynamics of Polychlorinated Biphenyl-Dechlorinating Microorganisms in Contaminated Sediments

    OpenAIRE

    Kim, J.; Rhee, G.

    1997-01-01

    The growth dynamics of polychlorinated biphenyl (PCB)-dechlorinating microorganisms were determined for the first time, along with those of sulfate reducers and methanogens, by using the most-probable-number technique. The time course of Aroclor 1248 dechlorination mirrored the growth of dechlorinators; dechlorination ensued when the dechlorinating population increased by 2 orders of magnitude from 2.5 x 10(sup5) to 4.6 x 10(sup7) cells g of sediment(sup-1), at a specific growth rate of 6.7 d...

  13. Radiolytic dechlorination of polychlorinated biphenyls in transformer oil and in marine sediment

    International Nuclear Information System (INIS)

    Radiolytic dechlorination of polychlorinated biphenyls (PCBs) in transformer oil and in marine sediments has been studied. At low PCB concentrations, complete degradation of the PCBs in transformer oil was achieved without degradation of the oil. Addition of an organic base, triethylamine, enhances the radiolytic dechlorination yield. The mechanism of dechlorination has been shown to involve electron transfer to PCBs from various aromatic radical anions formed in the irradiated oil. At high PCB concentrations, large amounts of triethylamine were necessary to achieve complete radiolytic dechlorination. Preliminary results on PCB-contaminated marine sediments demonstrate that addition of 2-propanol to the sediment/water slurry increases the effectiveness of the electron beam treatment

  14. Polychlorinated biphenyl concentrations in adipose tissue as determinants of abdominal obesity in the Elderly

    DEFF Research Database (Denmark)

    Bräuner, Elvira; Raaschou-Nielsen, Ole; Andersen, Zorana;

    2013-01-01

    explain the epidemic. Evidence from animal experiments suggests that exposure to endocrine disruptors such as PCBs is associated with the development of obesity but our knowledge of the effects of these compounds on weight gain in humans is limited. Our objective was to investigate the association between...... circumference 5 years after enrolment. We examined ten polychlorinated biphenyl congeners (PCBs) as potential determinants. All PCBs included were positively associated with increased abdominal circumference, although this association was not significant. These data do not support the hypotheses of a link...

  15. Polychlorinated biphenyls in serum and time to pregnancy

    International Nuclear Information System (INIS)

    Polychlorinated biphenyls (PCBs) may affect the female reproductive system in both animals and humans. In Sweden, a main exposure source to PCBs is consumption of fatty fish from the Baltic Sea. From 165 female consumers of such fish (fishermen's sisters), information on time to pregnancy (TTP) and miscarriages was collected, blood was drawn, and serum was analyzed for 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153), a biomarker for total PCB exposure. TTP and miscarriage data, as well as plasma CB-153 concentrations, for 121 fishermen's wives were available from previous studies. Thus, information on 286 women was available for investigation of whether a high exposure to PCB affects fertility negatively by increasing the TTP. The concentrations of CB-153 at the time of conception were estimated and trichotomized into low, medium, and high exposure groups. When we analyzed the joint data set of fishermen's wives and fishermen's sisters, a decrease rather than an increase in TTP was indicated for women in the medium (fecundability ratio 1.27 [95% confidence interval 0.89-1.82]) and high (fecundability ratio 1.42 [0.99-2.03]) exposure groups compared to those in the low exposure group. Similar results were found when we stratified on the original data set (fishermen's wives and fishermen's sisters) or childhood exposure. Women with miscarriages had lower estimated past CB-153 concentrations than women with live births. Our data provide no evidence of a hazardous effect associated with CB-153 concentration in the exposure range assessed. The exposure levels found in the fishermen's families, although high compared to that in the general Swedish population, may not be high enough to negatively affect fertility

  16. Consumption of both low and high (-)-epicatechin apple puree attenuates platelet reactivity and increases plasma concentrations of nitric oxide metabolites: A randomized controlled trial

    NARCIS (Netherlands)

    Gasper, A.; Hollands, W.; Casgrain, A.; Saha, S.; Teucher, B.; Dainty, J.R.; Venema, D.P.; Hollman, P.C.H.

    2014-01-01

    We hypothesised that consumption of flavanol-containing apple puree would modulate platelet activity and increase nitric oxide metabolite status, and that high flavanol apple puree would exert a greater effect than low flavanol apple puree. 25 subjects consumed 230 g of apple puree containing 25 and

  17. Danish emission inventory for hexachlorobenzene and polychlorinated biphenyls

    DEFF Research Database (Denmark)

    Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt; Winther, Morten;

    This report documents the improved air emission inventories for hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs). The emission inventories now include all sources covered by the EMEP/EEA Guidebook. The completeness and accuracy of the inventories for these pollutants have been signifi...

  18. 77 FR 54818 - Polychlorinated Biphenyls (PCBs): Revisions to Manifesting Regulations

    Science.gov (United States)

    2012-09-06

    ... AGENCY 40 CFR Part 761 RIN 2050-AG71 Polychlorinated Biphenyls (PCBs): Revisions to Manifesting... manifesting requirements for PCBs under TSCA to the manifesting requirements for hazardous waste under RCRA... bring into alignment, as much as possible, the manifesting requirements for PCBs to those of...

  19. Polychlorinated Biphenyls: In situ Bioremediation from the Environment

    Science.gov (United States)

    Polychlorinated biphenyls (PCBs) are a group of hydrophobic and stable organic compounds consisting of 209 possible congeners. Because of their unique physico-chemical properties, PCBs were used in a wide range of industrial applications. The properties that made PCBs useful in i...

  20. FIBER OPTIC FLUOROIMMUNOSENSOR FOR THE DETECTION OF POLYCHLORINATED BIPHENYLS

    Science.gov (United States)

    There currently exists a critical and growing need for cost-effective, real-time, and in situ methods for detection of environmental pollutants such as polychlorinated biphenyls (PCBs). erein reported is a evanescent wave Fluoroimmunosensor for measurement of PCBS. 2,4-5-Trichlor...

  1. Polychlorinated Biphenyl Sorption and Availability in Field-Contaminated Sediments†

    OpenAIRE

    Werner, David; Hale, Sarah E.; Ghosh, Upal; Luthy, Richard G.

    2009-01-01

    Traditional and new relationships of polychlorinated biphenyl (PCB) distribution among the solid phases, the free aqueous phase, and biolipids are comprehensively reviewed using seven well-characterized freshwater and marine sediments polluted with PCBs. The traditional relationship relating free aqueous concentration and biolipid concentration to sediment total organic carbon, compound octanol−water partitioning coefficient, and solid-phase contaminant concentration overestimates measured fr...

  2. Enzymatic Dysfunction of Mitochondrial Complex I of the Candida albicans goa1 Mutant Is Associated with Increased Reactive Oxidants and Cell Death ▿

    OpenAIRE

    Li, Dongmei; Chen, Hui; Florentino, Abigail; Alex, Deepu; Sikorski, Patricia; Fonzi, William A.; Calderone, Richard

    2011-01-01

    We have previously shown that deletion of GOA1 (growth and oxidant adaptation) of Candida albicans results in a loss of mitochondrial membrane potential, ATP synthesis, increased sensitivity to oxidants and killing by human neutrophils, and avirulence in a systemic model of candidiasis. We established that translocation of Goa1p to mitochondria occurred during peroxide stress. In this report, we show that the goa1Δ (GOA31), compared to the wild type (WT) and a gene-reconstituted (GOA32) strai...

  3. Consumption of both low and high (-)-epicatechin apple puree attenuates platelet reactivity and increases plasma concentrations of nitric oxide metabolites: a randomized controlled trial.

    Science.gov (United States)

    Gasper, Amy; Hollands, Wendy; Casgrain, Amelie; Saha, Shikha; Teucher, Birgit; Dainty, Jack R; Venema, Dini P; Hollman, Peter C; Rein, Maarit J; Nelson, Rebecca; Williamson, Gary; Kroon, Paul A

    2014-10-01

    We hypothesised that consumption of flavanol-containing apple puree would modulate platelet activity and increase nitric oxide metabolite status, and that high flavanol apple puree would exert a greater effect than low flavanol apple puree. 25 subjects consumed 230 g of apple puree containing 25 and 100mg epicatechin (low and high flavanol apple puree, respectively) and aspirin (75 mg) in random order. Measurements were made at baseline, acutely after treatment (2, 6 and 24 h), and after 14 d of treatment. Low flavanol apple puree significantly attenuated ADP and epinephrine-induced integrin-β3 expression 2 h and 6 h after consumption and ADP and epinephrine-induced P-selectin expression within 2h of consumption. High flavanol apple puree attenuated epinephrine and ADP-induced integrin-β3 expression after 2 and 6h. ADP and epinephrine-induced integrin-β3 expression was significantly attenuated 2, 6 and 24 h after consumption of aspirin, whilst 14 d aspirin consumption attenuated collagen-induced P-selectin expression only. The plasma total nitric oxide metabolite conc. was significantly increased 6h after consumption of both low and high flavanol apple purees. In conclusion, consumption of apple purees containing ⩾25 or 100 mg flavanols transiently attenuated ex vivo integrin-β3 and P-selectin expression and increased plasma nitric oxide metabolite conc. in healthy subjects, but the effect was not enhanced for the high flavanol apple puree. PMID:24929184

  4. Formation of Polychlorinated Biphenyls on Secondary Copper Production Fly Ash: Mechanistic Aspects and Correlation to Other Persistent Organic Pollutants

    OpenAIRE

    Xiaoxu Jiang; Guorui Liu; Mei Wang; Minghui Zheng

    2015-01-01

    Emission of unintentionally formed polychlorinated biphenyls (PCBs) from industrial thermal processes is a global issue. Because the production and use of technical PCB mixtures has been banned, industrial thermal processes have become increasingly important sources of PCBs. Among these processes, secondary copper smelting is an important PCB source in China. In the present study, the potential for fly ash-mediated formation of PCBs in the secondary copper industry, and the mechanisms involve...

  5. Polychlorinated biphenyls in Spanish adults: Determinants of serum concentrations

    International Nuclear Information System (INIS)

    Background: Polychlorinated biphenyls (PCBs) are persistent compounds that may pose an environmental hazard to humans, food being the main source of exposure for the general population. Objective: To measure the serum concentrations of the main PCBs in subjects from the general population in Spain, and to assess potential determinants of such concentrations. Methods: Serum was obtained from blood samples of 953 subjects aged 35-64 years, residents in five Spanish regions (three from the North and two from the South), randomly selected from the EPIC-Spain cohort. Blood collection took place during 1992-1996 and four PCB congeners (118, 138, 153 and 180) were determined by means of gas chromatography with electron-capture detection (GC-ECD). Results: The concentration of total PCBs was 459 ng/g lipids (or 3.1 μg/l); the corresponding figures for PCB 153 were 186 ng/g lipids and 1.25 μg/l. Men had higher values than women, PCB levels increased with age, and serum concentration of PCBs was higher in northern regions. Body mass index (BMI) was inversely related to PCB concentrations, and fish intake was the dietary factor showing the greatest association with serum PCBs. The pattern described was similar for each congener separately. Conclusions: We found concentrations similar to those reported in European countries where blood collection was carried during the same period. Regional differences within Spain are not fully explained by anthropometric or dietary factors. The inverse association with BMI suggests that in the mid-1990s there was still ongoing or recent exposure to PCBs in Spain.

  6. Polychlorinated biphenyls in Spanish adults: Determinants of serum concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Agudo, Antonio, E-mail: a.agudo@iconcologia.net [Unit of Nutrition, Environment, and Cancer, Cancer Epidemiology Research Program, Catalan Institute of Oncology (ICO), IDIBELL, Av. Gran Via no 199-203, 08907 L' Hospitalet de Llobregat (Spain); Goni, Fernando [Laboratorio de Salud Publica de Guipuzcoa, 20013 San Sebastian (Spain); CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Etxeandia, Arsenio [Laboratorio de Salud Publica de Vizcaya, 48010 Bilbao (Spain); Vives, Asuncion [Laboratorio Unificado Donostia, Hospital N. S. Aranzazu, 20014 San Sebastian (Spain); Millan, Esmeralda [Departamento de Quimica Aplicada, Universidad del Pais Vasco, Facultad de Quimica, 20080 San Sebastian (Spain); Lopez, Raul [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Amiano, Pilar [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Direccion de Salud de Guipuzcoa, 20013 San Sebastian (Spain); Ardanaz, Eva; Barricarte, Aurelio [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Instituto de Salud Publica de Navarra, 31003 Pamplona (Spain); Dolores Chirlaque, M. [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Consejeria de Sanidad, 3008 Murcia (Spain); Dorronsoro, Miren [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Direccion de Salud de Guipuzcoa, 20013 San Sebastian (Spain); Jakszyn, Paula [Unit of Nutrition, Environment, and Cancer, Cancer Epidemiology Research Program, Catalan Institute of Oncology (ICO), IDIBELL, Av. Gran Via no 199-203, 08907 L' Hospitalet de Llobregat (Spain); Larranaga, Nerea [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Direccion de Salud de Guipuzcoa, 20013 San Sebastian (Spain); Martinez, Carmen [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Escuela Andaluza de Salud Publica, 18080 Granada (Spain); Navarro, Carmen [CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Consejeria de Sanidad, 3008 Murcia (Spain); Rodriguez, Laudina [Consejeria de Salud y Servicios Sanitarios de Asturias, 33001 Oviedo (Spain); and others

    2009-07-15

    Background: Polychlorinated biphenyls (PCBs) are persistent compounds that may pose an environmental hazard to humans, food being the main source of exposure for the general population. Objective: To measure the serum concentrations of the main PCBs in subjects from the general population in Spain, and to assess potential determinants of such concentrations. Methods: Serum was obtained from blood samples of 953 subjects aged 35-64 years, residents in five Spanish regions (three from the North and two from the South), randomly selected from the EPIC-Spain cohort. Blood collection took place during 1992-1996 and four PCB congeners (118, 138, 153 and 180) were determined by means of gas chromatography with electron-capture detection (GC-ECD). Results: The concentration of total PCBs was 459 ng/g lipids (or 3.1 {mu}g/l); the corresponding figures for PCB 153 were 186 ng/g lipids and 1.25 {mu}g/l. Men had higher values than women, PCB levels increased with age, and serum concentration of PCBs was higher in northern regions. Body mass index (BMI) was inversely related to PCB concentrations, and fish intake was the dietary factor showing the greatest association with serum PCBs. The pattern described was similar for each congener separately. Conclusions: We found concentrations similar to those reported in European countries where blood collection was carried during the same period. Regional differences within Spain are not fully explained by anthropometric or dietary factors. The inverse association with BMI suggests that in the mid-1990s there was still ongoing or recent exposure to PCBs in Spain.

  7. Maneb disturbs expression of superoxide dismutase and glutathione peroxidase, increases reactive oxygen species production, and induces genotoxicity in liver of adult mice.

    Science.gov (United States)

    Ben Amara, Ibtissem; Ben Saad, Hajer; Hamdaoui, Latifa; Karray, Aida; Boudawara, Tahia; Ben Ali, Yassine; Zeghal, Najiba

    2015-08-01

    Maneb (MB), a fungicide largely used in agriculture throughout the world including Tunisia, protects many vegetables, fruits and field crops against a wide spectrum of fungal diseases. However there is a lack of informations regarding the risks arising from MB exposure on non target organisms, especially mammals. The aim of this study was to investigate the morphological, biochemical and molecular aspects of liver injury after exposure of mice to MB. Four doses of MB corresponding to 1/8 (group D1), 1/6 (group D2), 1/4 (group D3), and 1/2 (group D4) of lethal dose (DL50 = 1500 mg/kg body weight) were administered to adult mice. Oxidative stress parameters were also objectified by molecular and histological endpoints in the liver. Maneb caused hepatotoxicity as characterized by the significant increase in the levels of malondialdehyde and protein oxidation marker, advanced oxidation protein products (AOPP). The activities of catalase, glutathione peroxidase, superoxide dismutase and the levels of glutathione decreased significantly in all treated mice, while vitamin C levels decreased only in group D4. We also noted a significant decrease in gene expression of superoxide dismutase and glutathione peroxidase enzymes. Maneb caused nucleic acids degradation testifying its genotoxicity. Yet, biochemical markers in plasma showed a decrease in total protein and an increase in aspartate, alanine amino transferases and bilirubin levels in all treatment groups. Moreover, plasma levels of cholesterol, triglycerides and low density lipoprotein-cholesterol significantly increased, while those of high density lipoprotein-cholesterol decreased. These biochemical alterations were correlated with significantly histological changes. Our data showed, for the first time, that intraperitoneal injection of very high non environmentally relevant MB concentrations to adult mice resulted in oxidative stress leading to hepatotoxicity and the impairment of defense systems, confirming the

  8. PEGylation of G-CSF in organic solvent markedly increase the efficacy and reactivity through protein unfolding, hydrolysis inhibition and solvent effect.

    Science.gov (United States)

    Peng, Fei; Liu, Yongdong; Li, Xiunan; Sun, Lijing; Zhao, Dawei; Wang, Qingqing; Ma, Guanghui; Su, Zhiguo

    2014-01-20

    Previous studies demonstrated that hydrophobic proteins could be PEGylated in organic phase rather than water phase. It is still not known what the difference is for a hydrophilic protein's PEGylation in these two different phases. In this study, granulocyte colony stimulating factor (G-CSF) was dissolved in neat dimethyl sulfoxide (DMSO) and was PEGylated. In comparison with the PEGylation in water solution, the PEGylation degree in the organic solvent increased by 33% and 42% for PEG-maleimide (MAL-PEG) and PEG-succinimidyl carbonate (SC-PEG) respectively. Structure analysis revealed that the protein was unfolded in DMSO, which could make the PEGylated sites of G-CSF easily accessible. The hydrolysis half-life in water solution was 40min and 9h for SC-PEG and MAL-PEG respectively. However, in DMSO solvent, PEGs were very stable and no hydrolysis could be detected. Stopped-flow demonstrated that the conjugation speed of G-CSF by MAL-PEG and SC-PEG in DMSO were 1.6×10(4) and 2×10(2) times faster than those in aqueous solution. The remarkable acceleration could mainly be attributed to an increase of protein nucleophilicity in DMSO. The results of this study could be referential to industrial application where the cost of PEG reagents and the speed of reaction on large scale are very important. PMID:24315970

  9. Biphenyl-utilizing bacteria and their functional genes in a pine root zone contaminated with polychlorinated biphenyls (PCBs)

    Czech Academy of Sciences Publication Activity Database

    Leigh, M. B.; Pellizari, V. H.; Uhlík, Ondřej; Sutka, R.; Rodrigues, J.; Ostrom, N. E.; Zhou, J.; Tiedje, J. M.

    2007-01-01

    Roč. 1, č. 2 (2007), s. 134-148. ISSN 1751-7362 Institutional research plan: CEZ:AV0Z40550506 Keywords : polychlorinated biphenyls * rhizosphere * aromatic dioxygenase * bioremediation Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides

  10. Directing effects of phenyl substitution in the reaction of OH radical with aromatics: The radiolytic hydroxylation of biphenyl

    International Nuclear Information System (INIS)

    The initial yields for formation of 2-, 3- and 4- hydroxybiphenyl following the radiolytic oxidation of biphenyl in the presence of ferricyanide are, respectively, 2.19, 1.13 and 1.55 molecules/100eV. These yields reflect relative rates of 0.71:0.37:1 for sm-bulletOH radical attack on each of the ortho, meta, and para positions of biphenyl. Comparison of the corresponding partial rate constants to that for benzene shows that phenyl substitution has a significant effect in directing sm-bulletOH addition to the ortho and para positions of aromatic systems. Comparison with phenol shows that a phenyl substitution has only a slightly smaller effect than does OH in increasing the partial rate constant at the ortho and para positions but is substantially less effective in decreasing the rate of sm-bulletOH reaction at the meta position. 15 refs., 9 figs

  11. BACKGROUND CONTAMINATION BY COPLANAR POLYCHLORINATED BIPHENYLS (PCBS) IN TRACE LEVEL HIGH RESOLUTION GAS CHROMATOGRAPHY/HIGH RESOLUTION MASS SPECTROMETRY (HRGC/HRMS) ANALYTICAL PROCEDURES

    Science.gov (United States)

    The addition of the "dioxin-like" polychlorinated biphenyl (PCB) congeners to the assessment of risk associated with the 2,3,7,8-chlorine substituted dioxins and furans has dramatically increased the number of laboratories worldwide that are developing analytical procedures for t...

  12. Decreased sex ratio following maternal exposure to polychlorinated biphenyls from contaminated Great Lakes sport-caught fish: a retrospective cohort study.

    Directory of Open Access Journals (Sweden)

    Anderson Henry A

    2003-03-01

    Full Text Available Abstract Background Fish from the Great Lakes are contaminated with polychlorinated biphenyls, which have been found to have several adverse reproductive effects. Several environmental contaminants have been found to alter the sex ratio of offspring at birth, but the evidence of such an effect of polychlorinated biphenyls has been inconsistent. Methods We examined parental serum polychlorinated biphenyl concentration in relation to the sex ratio of 173 children of mothers and 208 children of fathers from the Great Lakes region of the United States between 1970 and 1995. We calculated odds ratios for a male child using logistic regression and generalized estimating equations with adjustment for the year of birth of the child, maternal and paternal age, the mother's parity at the child's birth, and whether the child had an older brother. Results The adjusted odds ratio for having a male child among mothers in the highest quintile of serum polychlorinated biphenyl concentration was 0.18 (95% CI: 0.06–0.59 compared to mothers in the lowest quintile. Treating exposure as a continuous variable, the adjusted odds ratio for having a male child was 0.54 per unit increase in the natural log of maternal serum polychlorinated biphenyl concentration (95% CI: 0.33–0.89. There was little evidence of an association with paternal exposure. We found no association between either maternal or paternal serum dichlorodiphenyl-dichloroethene concentration and the sex ratio. Conclusions These findings suggest that maternal exposure to polychlorinated biphenyls may decrease the sex ratio of offspring. These data add to the growing body of evidence that exposure to particular chemicals can alter the sex ratio at birth.

  13. Plasma polychlorinated biphenyl concentrations and immune function in postmenopausal women

    Energy Technology Data Exchange (ETDEWEB)

    Spector, June T., E-mail: spectj@uw.edu [Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 (United States); Department of Medicine, School of Medicine, University of Washington, Seattle, WA (United States); De Roos, Anneclaire J., E-mail: ajd335@drexel.edu [Epidemiology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N, P.O. Box 19024, Seattle, WA 98109 (United States); Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA (United States); Ulrich, Cornelia M., E-mail: neli.ulrich@nct-heidelberg.de [Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA (United States); Cancer Prevention Program, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N, P.O. Box 19024, Seattle, WA 98109 (United States); National Center for Tumor Diseases and German Cancer Research Center, Heidelberg (Germany); Sheppard, Lianne, E-mail: sheppard@uw.edu [Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, 4225 Roosevelt Way NE, Seattle, WA 98105 (United States); Department of Biostatistics, School of Public Health, University of Washington, Seattle, WA (United States); Sjoedin, Andreas, E-mail: asjodin@cdc.gov [National Center for Environmental Health, CDC, 4770 Buford Highway NE, Atlanta, GA 30341 (United States); Wener, Mark H., E-mail: wener@u.washington.edu [Department of Medicine, School of Medicine, University of Washington, Seattle, WA (United States); Wood, Brent, E-mail: woodbl@u.washington.edu [Department of Medicine, School of Medicine, University of Washington, Seattle, WA (United States); and others

    2014-05-01

    Background: Polychlorinated biphenyl (PCB) exposure has been associated with non-Hodgkin lymphoma in several studies, and the immune system is a potential mediator. Objectives: We analyzed associations of plasma PCBs with immune function measures. We hypothesized that higher plasma PCB concentrations are associated with lower immune function cross-sectionally, and that increases in PCB concentrations over a one year period are associated with decreases in immune function. Methods: Plasma PCB concentrations and immune function [natural killer (NK) cell cytotoxicity and PHA-induced T-lymphocyte proliferation (PHA-TLP)] were measured at baseline and one year in 109 postmenopausal overweight women participating in an exercise intervention study in the Seattle, Washington (USA) area. Mixed models, with adjustment for body mass index and other potential confounders, were used to estimate associations of PCBs with immune function cross-sectionally and longitudinally. Results: Associations of PCBs with immune function measures differed across groups of PCBs (e.g., medium- and high-chlorinated and dioxin-like [mono-ortho-substituted]) and by the time frame for the comparison (cross-sectional vs. longitudinal). Higher concentrations of medium- and high-chlorinated PCBs were associated with higher PHA-TLP cross-sectionally but not longitudinally. The mean decrease in 0.5 µg/mL PHA-TLP/50.0 pmol/g-lipid increase in dioxin-like PCBs over one year was 51.6 (95% confidence interval 2.7, 100.5; P=0.039). There was no association between plasma PCBs and NK cytotoxicity. Conclusions: These results do not provide strong evidence of impaired cellular immunity from PCB exposure. Larger longitudinal studies with greater variability in PCB exposures are needed to further examine temporal associations of PCBs with immune function. - Highlights: • Plasma PCBs and immune function were measured in 109 women at baseline and one year. • Immune measures included T lymphocyte proliferation

  14. Plasma polychlorinated biphenyl concentrations and immune function in postmenopausal women

    International Nuclear Information System (INIS)

    Background: Polychlorinated biphenyl (PCB) exposure has been associated with non-Hodgkin lymphoma in several studies, and the immune system is a potential mediator. Objectives: We analyzed associations of plasma PCBs with immune function measures. We hypothesized that higher plasma PCB concentrations are associated with lower immune function cross-sectionally, and that increases in PCB concentrations over a one year period are associated with decreases in immune function. Methods: Plasma PCB concentrations and immune function [natural killer (NK) cell cytotoxicity and PHA-induced T-lymphocyte proliferation (PHA-TLP)] were measured at baseline and one year in 109 postmenopausal overweight women participating in an exercise intervention study in the Seattle, Washington (USA) area. Mixed models, with adjustment for body mass index and other potential confounders, were used to estimate associations of PCBs with immune function cross-sectionally and longitudinally. Results: Associations of PCBs with immune function measures differed across groups of PCBs (e.g., medium- and high-chlorinated and dioxin-like [mono-ortho-substituted]) and by the time frame for the comparison (cross-sectional vs. longitudinal). Higher concentrations of medium- and high-chlorinated PCBs were associated with higher PHA-TLP cross-sectionally but not longitudinally. The mean decrease in 0.5 µg/mL PHA-TLP/50.0 pmol/g-lipid increase in dioxin-like PCBs over one year was 51.6 (95% confidence interval 2.7, 100.5; P=0.039). There was no association between plasma PCBs and NK cytotoxicity. Conclusions: These results do not provide strong evidence of impaired cellular immunity from PCB exposure. Larger longitudinal studies with greater variability in PCB exposures are needed to further examine temporal associations of PCBs with immune function. - Highlights: • Plasma PCBs and immune function were measured in 109 women at baseline and one year. • Immune measures included T lymphocyte proliferation

  15. What Is Reactive Arthritis?

    Science.gov (United States)

    ... Arthritis PDF Version Size: 69 KB November 2014 What is Reactive Arthritis? Fast Facts: An Easy-to- ... Information About Reactive Arthritis and Other Related Conditions What Causes Reactive Arthritis? Sometimes, reactive arthritis is set ...

  16. The reactivity meter and core reactivity

    International Nuclear Information System (INIS)

    The point kinetic equations and the characteristics of the point kinetic reactivity meter are discussed, particularly for large negative reactivities. From a given input signal representing the neutron flux seen by a detector, the meter computes a value of reactivity in dollars (ρ/β), based on inverse point kinetics. The prompt jump point of view is emphasised. A simple point model of the reactor and a local flux distortion factor are used to generate input signals into a simulated reactivity meter. The obtained results show how the reading of the reactivity meter will approach the reactivity of the core model, if the reactivity is lower than -1 dollars. However, for reactivity values higher than -1 dollars, the influence of the flux distortion on the reading of the reactivity meter persists. Reactivity meter measurements taken during typical rod drop experiments in VVER-440 reactors do not produce accurate indications of the (static) core reactivity. (author)

  17. Tissue damage after acute intoxication by polychlorinated biphenyls (PCBs in cockroaches Blattella germanica

    Directory of Open Access Journals (Sweden)

    S Lambiase

    2009-06-01

    Full Text Available It is common knowledge that polychlorinated biphenyls (PCBs represent a serious threat to the health of both vertebrates and invertebrates. As far as the former are concerned, especially as regards human beings, a broad literature describes the direct and indirect effects induced by the PCBs on their systems and organs. Among invertebrates, the information available is mostly related to arthropods and is, however, very scarce. The aim of this work was to evaluate the effects of polychlorinated biphenyls (PCBs on tissues and organs of individuals belonging to a species of Blattaria (Blattella germanica treated with various doses of this toxic material. The pathologies found became more serious as the dosage increased and were present throughout the entire digestive system, in the fat body and in the male gonads: in these areas cell and tissue breakdown and severely damaged spermiogenesis were observed. In particular, the testicles, Malpighian tubules and fat body accumulated an amorphous basophilic PAS-positive substance. Furthermore, the NOS-dependent NADPH diaphorase activity pattern in the retina and optic lobes was more evident in the treated than in the control insects.

  18. The associations between the environmental exposure to polychlorinated biphenyls (PCBs) and breast cancer risk and progression

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Polychlorinated biphenyls(PCBs) are chlorinated biphenyl compounds with wide applications in the industry.In spite of a ban on their production in the late 1970s,PCBs,as a group of POPs,are still persistent and widely spread in the environment,posing potential threats to human health.The role of PCBs as etiologic agents for breast cancer has been intensively explored in a variety of in vivo,animal and epidemiologic studies.Initial investigations indicated higher levels of PCBs in mammary tissues or sera corresponded to the occurrence of breast cancer,but later studies showed no positive association between PCB exposure and breast cancer development.More recent data suggested that the CYP1A1 m2 polymorphisms might add increased risk to the etiology of breast cancer in women with environmental exposure to PCBs.PCBs are implicated in advancing breast cancer progression,and our unpublished data reveals that PCBs activate the ROCK signaling to enhance breast cancer metastasis.Therefore,the correlation between PCB exposure and breast cancer risk warrants further careful investigations.

  19. Effects of pre- and postnatal polychlorinated biphenyl exposure on emotional reactivity observed in lambs before weaning.

    Science.gov (United States)

    Gutleb, Arno C; Lilienthal, Hellmuth; Erhard, Hans W; Zimmer, Karin E; Skaare, Janneche Utne; Ropstad, Erik

    2011-07-01

    Humans and animals are exposed to PCBs and influences on developmental and endocrine processes are among the most pronounced effects. In the present study it was hypothesised that exposure to PCBs may interfere with sexually dimorphic behaviour. To test this hypothesis, behavioural studies in developmentally exposed sheep were conducted. Ewes were orally administered PCB 153 (98 μg/kg bw day), PCB 118 (49 μg/kg bw day) or corn oil from conception until delivery. However, because of accidental cross-contamination occurring twice causing a mixed exposure scenario in all three groups, the focus of this paper is to compare three distinct groups of lambs with different PCB levels (PCB 153 high-PCB 153 h, PCB 118 high-PCB 118 h, and low combined group-LC) rather than comparing animals exposed to single PCB congeners to those of a control group. Lambs were tested between 2 and 6 weeks of age. When LC males started the light/dark choice test in a dark box, they spent significantly more time in the dark part of the pen than LC females. This gender-related difference was not found in groups exposed to PCBs. A significant inhibitory effect on the activity level of males exposed to stress of confinement was found in the PCB 118 h group. In a high stress situation females from PCB 118 h and males from PCB 153 h were less active than their gender counterparts. The results support the hypothesis that intrauterine exposure to PCBs can alter sexually dimorphic behaviour of offspring. PMID:21450342

  20. Role of inhalation in exposure to polychlorinated biphenyls (PCBs)

    International Nuclear Information System (INIS)

    Polychlorinated biphenyls (PCBs) are a group of aromatic compounds consisting of a biphenyl variously chlorinated. Industrial production of PCBs started in 1929 and stopped in the second half of the '70s in USA and in the late 80's and 90's in Europe. PCBs are ubiquitous pollutants. The way of human exposure to PCBs is a matter of discussion. Scientific data show that the greater exposure occurs through diet. However, other available data suggest a not marginal role of the inhalation exposure. The sources of PCBs to which population are exposed depend on the amount of redistribution of these compounds released in the environment. The aim of this work is to highlight numerous studies proving that the intake of PCBs by inhalation cannot be neglected, in particular in heavily industrialized areas and where the concentration of PCBs in the environmental matrices is particularly high

  1. Dehalorespiration with Polychlorinated Biphenyls by an Anaerobic Ultramicrobacterium▿

    OpenAIRE

    May, Harold D.; Miller, Greg S.; Birthe V. Kjellerup; Sowers, Kevin R.

    2008-01-01

    Anaerobic microbial dechlorination is an important step in the detoxification and elimination of polychlorinated biphenyls (PCBs), but a microorganism capable of coupling its growth to PCB dechlorination has not been isolated. Here we describe the isolation from sediment of an ultramicrobacterium, strain DF-1, which is capable of dechlorinating PCBs containing double-flanked chlorines added as single congeners or as Aroclor 1260 in contaminated soil. The isolate requires Desulfovibrio spp. in...

  2. The Influence of Polychlorinated Biphenyls Contamination on Soil Protein Expression

    OpenAIRE

    Xi Zhang; Feng Li; Tingting Liu; Cheng Peng; Dechao Duan; Chen Xu; Shenhai Zhu; Jiyan Shi

    2013-01-01

    Polychlorinated biphenyls (PCBs) are typical representative of chlorinated organic pollutants. Given the toxicity of PCBs, there is an urgent need to select an appropriate indicator to monitor their biological effects on soil ecosystems. For this purpose, we investigated the impacts of PCBs on soil protein and the potential of using protein as a biological indicator to assess soil contamination due to PCBs. This study demonstrated that soil protein concentration and expression were negatively...

  3. Anaerobic Dehalogenation of Hydroxylated Polychlorinated Biphenyls by Desulfitobacterium dehalogenans

    OpenAIRE

    Wiegel, Juergen; Zhang, Xiaoming; Wu, Qingzhong

    1999-01-01

    Ten years after reports on the existence of anaerobic dehalogenation of polychlorinated biphenyls (PCBs) in sediment slurries, we report here on the rapid reductive dehalogenation of para-hydroxylated PCBs (HO-PCBs), the excreted main metabolites of PCB in mammals, which can exhibit estrogenic and antiestrogenic activities in humans. The anaerobic bacterium Desulfitobacterium dehalogenans completely dehalogenates all flanking chlorines (chlorines in ortho position to the para-hydroxyl group) ...

  4. Toxicity mechanisms and interactions of polychlorinated biphenyls and polybrominated diphenylethers

    OpenAIRE

    Antonijević Biljana; Milovanović Vesna; Ćurčić Marijana; Janković Saša; Jaćević Vesna; Vučinić Slavica

    2012-01-01

    Polychlorinated biphenyls (PCBs) and brominated flame retardants, polybrominated diphenylethers (PBDEs), are widespread environmental contaminants as a result of anthropogenic activities and due to their persistency and resistance to degradation. Both groups of chemicals are placed on the list of persistent organic pollutants (POPs), covered by the Stockholm convention which is aimed to limit or ban the production, use, emission, import and export of POPs i...

  5. Analysis of polychlorinated biphenyls (PCBs) in human serum.

    OpenAIRE

    Luotamo, M; Järvisalo, J; Aitio, A

    1985-01-01

    Polychlorinated biphenyls (PCBs) are widely dispersed in the environment. Occupational exposure to PCBs takes place, e.g., in manufacture and repair of capacitors and transformers. A special type of exposure of workers to PCBs may occur in connection with accidents where capacitors or transformers containing PCBs products are damaged, as in the case of a fire or electric arcing. The quantitation of PCBs poses several problems: There are 209 different homologs and isomers of PCBs. The isomers ...

  6. Polychlorinated Biphenyl (PCB) carcinogenicity with special emphasis on airborne PCBs

    OpenAIRE

    Robertson, Larry W.; Ludewig, Gabriele

    2011-01-01

    Polychlorinated biphenyls (PCBs) are industrial chemicals used in various applications requiring chemical stabilityand have now become widely dispersed. Their characteristics of persistence, low water/higher lipid solubility, contribute to their ability to bioconcentrate and bioaccumulate. Traditionally PCBs have been regulated as food contaminants and the general population is primarily exposed by that route. PCBs in foodstuffs are generally higher chlorinated, resistant to metabolic breakdo...

  7. Binding of polychlorinated biphenyls to the aryl hydrocarbon receptor.

    OpenAIRE

    Kafafi, S A; Afeefy, H Y; A. H. Ali; Said, H K; Kafafi, A G

    1993-01-01

    A new thermodynamic model for calculating the dissociation constants of complexes formed between the aryl hydrocarbon receptor (AhR) and polychlorinated biphenyls (PCBs) is reported. The free energies of binding of PCBs to AhR are controlled by their lipophilicities, electron affinities, and entropies. The corresponding physicochemical properties of polychlorinated dibenzo-p-dioxins and dibenzofurans also control their interactions with AhR. We present evidence supporting the hypothesis that ...

  8. Gas chromatographic separation of methoxylated polychlorinated biphenyl atropisomers

    OpenAIRE

    Kania-Korwel, Izabela; Vyas, Sandhya M.; Song, Yang; Lehmler, Hans-Joachim

    2008-01-01

    Several polychlorinated biphenyls (PCBs) and their hydroxylated metabolites display axial chirality. Here we describe an enantioselective, gas chromatographic separation of methylated derivatives of hydroxylated (OH-)PCB atropisomers (MeO-PCB) using a chemically bonded β-cyclodextrin column (Chirasil-Dex). The atropisomers of several MeO-PCBs could be separated on this column with resolutions ranging from 0.42–0.87 under isothermal or temperature-programmed conditions. In addition, the enanti...

  9. Human Receptor Activation by Aroclor 1260, a Polychlorinated Biphenyl Mixture

    OpenAIRE

    Wahlang, Banrida; Falkner, K. Cameron; Clair, Heather B.; Al-Eryani, Laila; Prough, Russell A.; States, J. Christopher; Coslo, Denise M.; Omiecinski, Curtis J.; Cave, Matthew C.

    2014-01-01

    Polychlorinated biphenyls (PCBs) are persistent environmental toxicants, present in 100% of U.S. adults and dose-dependently associated with obesity and non-alcoholic fatty liver disease (NAFLD). PCBs are predicted to interact with receptors previously implicated in xenobiotic/energy metabolism and NAFLD. These receptors include the aryl hydrocarbon receptor (AhR), pregnane xenobiotic receptor (PXR), constitutive androstane receptor (CAR), peroxisome proliferator-activated receptors (PPARs), ...

  10. Polychlorinated Biphenyls Water Pollution along the River Nile, Egypt

    OpenAIRE

    Ayman Mohamed Megahed; Hesham Dahshan; Abd-El-Kader, Mahdy A.; Amr Mohamed Mohamed Abd-Elall; Mariam Hassan Elbana; Ehab Nabawy; Mahmoud, Hend A.

    2015-01-01

    Ten polychlorinated biphenyl (PCB) congeners were determined in water samples collected along the River Nile using gas chromatography-electron capture detector (GC-ECD). PCB concentrations ranged from 14 to 20 μg/L, which were higher than those reported in previous studies, indicating serious PCB pollution in the River Nile. PCB congener profiles varied depending on the sampling sties. PCB-138 was the predominant congener accounting for more than 18% of total PCBs. The composition of PCB cong...

  11. ACCUMULATION OF POLYCHLORINATED BIPHENYLS IN AQUATIC ORGANISMS AND ENVIRONMENT

    OpenAIRE

    ÇAKIROĞULLARI, Gül

    2010-01-01

    Polychlorinated biphenyls (PCBs) were discovered in the late of the 19th century and their usefulness for industry, because of their physical properties, was recognized early. The PCBs have been used commercially, since 1930, as dielectric and heat-exchange fluids and in a variety of other applications. They have become widely distributed in the environment throughout the world, and are persistent and accumulate in food webs. PCBs accumulate in the fatty tissues of humans and other animals an...

  12. Polychlorinated Biphenyl Presence in the Columbia River Corridor

    Energy Technology Data Exchange (ETDEWEB)

    R. M. Hermann

    2007-09-06

    The U. S. Department of Energy (DOE) is required by Comprehensive Environmental Response, Compensation, and Liability Act of 1980 regulations to develop a conceptual understanding of potential contaminant releases from the Hanford Site based on an evaluation of existing data and known historical practices. Polychlorinated biphenyls (PCBs) are one environmental contaminant potentially released through leaks, spills, or disposal. This document presents a summary of selected relevant existing information, including environmental studies and Hanford Site analytical data.

  13. Khz (fusion of Ganoderma lucidum and Polyporus umbellatus mycelia induces apoptosis by increasing intracellular calcium levels and activating JNK and NADPH oxidase-dependent generation of reactive oxygen species.

    Directory of Open Access Journals (Sweden)

    Tae Hwan Kim

    Full Text Available Khz is a compound derived from the fusion of Ganoderma lucidum and Polyporus umbellatus mycelia that inhibits the growth of cancer cells. The results of the present study show that Khz induced apoptosis preferentially in transformed cells and had only minimal effects on non-transformed cells. Furthermore, Khz induced apoptosis by increasing the intracellular Ca(2+ concentration ([Ca(2+](i and activating JNK to generate reactive oxygen species (ROS via NADPH oxidase and the mitochondria. Khz-induced apoptosis was caspase-dependent and occurred via a mitochondrial pathway. ROS generation by NADPH oxidase was critical for Khz-induced apoptosis, and although mitochondrial ROS production was also required, it appeared to occur secondary to ROS generation by NADPH oxidase. Activation of NADPH oxidase was demonstrated by the translocation of regulatory subunits p47(phox and p67(phox to the cell membrane and was necessary for ROS generation by Khz. Khz triggered a rapid and sustained increase in [Ca(2+](i, which activated JNK. JNK plays a key role in the activation of NADPH oxidase because inhibition of its expression or activity abrogated membrane translocation of the p47(phox and p67(phox subunits and ROS generation. In summary, these data indicate that Khz preferentially induces apoptosis in cancer cells, and the signaling mechanisms involve an increase in [Ca(2+](i, JNK activation, and ROS generation via NADPH oxidase and mitochondria.

  14. Role of rhizosphere microorganisms in phytoremediation of biphenyl in a contaminated groundwater plume

    International Nuclear Information System (INIS)

    This presentation discussed a pump and treat technology used in combination with a phytoremediation technology to remediate a biphenyl contaminated groundwater plume. Biphenyl is used in industrial applications as fungicide and heat transfer agent. It is highly toxic, has poor water solubility and sorbs strongly to soils. Costs for the project were estimated at $860,000 over a period of 20 years, while it was estimated that the addition of phytoremediation would cost only $125,000 over a period of 20 years. The phytoremediation containment area was added to the site which was comprised of a pump and treat system and landfill lagoons. In situ biodegradation of biphenyl was evaluated using microorganisms in poplar and willow rhizospheres. Basal salts were used as a culture medium. Methods to enhance biphenyl degradation were also investigated. Aerobic growth on biphenyl at temperatures of 8 degrees C were measured, and microbial populations were identified. The consortium with the highest biphenyl degradation was then analyzed. Major members were identified as Burkholderia xenovorans LB400 and a strain of Burkholderia xenovorans. Nitrate reduction, sulphate reduction, and methanogens were measured. Enrichment of anaerobic biphenyl degraders. Anaerobic biphenyl degradation was measured after 90 days. Details of anaerobic mineralization experiments were also provided. It was concluded that anaerobic biphenyl degradation was enhanced by TEA and fertilizer addition, as well as by poplar root exudate. tabs., figs

  15. Role of rhizosphere microorganisms in phytoremediation of biphenyl in a contaminated groundwater plume

    Energy Technology Data Exchange (ETDEWEB)

    Sun, B.; Ramsay, J. [Queen' s Univ., Kingston, ON (Canada). Dept. of Chemical Engineering

    2007-07-01

    This presentation discussed a pump and treat technology used in combination with a phytoremediation technology to remediate a biphenyl contaminated groundwater plume. Biphenyl is used in industrial applications as fungicide and heat transfer agent. It is highly toxic, has poor water solubility and sorbs strongly to soils. Costs for the project were estimated at $860,000 over a period of 20 years, while it was estimated that the addition of phytoremediation would cost only $125,000 over a period of 20 years. The phytoremediation containment area was added to the site which was comprised of a pump and treat system and landfill lagoons. In situ biodegradation of biphenyl was evaluated using microorganisms in poplar and willow rhizospheres. Basal salts were used as a culture medium. Methods to enhance biphenyl degradation were also investigated. Aerobic growth on biphenyl at temperatures of 8 degrees C were measured, and microbial populations were identified. The consortium with the highest biphenyl degradation was then analyzed. Major members were identified as Burkholderia xenovorans LB400 and a strain of Burkholderia xenovorans. Nitrate reduction, sulphate reduction, and methanogens were measured. Enrichment of anaerobic biphenyl degraders. Anaerobic biphenyl degradation was measured after 90 days. Details of anaerobic mineralization experiments were also provided. It was concluded that anaerobic biphenyl degradation was enhanced by TEA and fertilizer addition, as well as by poplar root exudate. tabs., figs.

  16. Synergistic Processing of Biphenyl and Benzoate: Carbon Flow Through the Bacterial Community in Polychlorinated-Biphenyl-Contaminated Soil

    Science.gov (United States)

    Leewis, Mary-Cathrine; Uhlik, Ondrej; Leigh, Mary Beth

    2016-02-01

    Aerobic mineralization of PCBs, which are toxic and persistent organic pollutants, involves the upper (biphenyl, BP) and lower (benzoate, BZ) degradation pathways. The activity of different members of the soil microbial community in performing one or both pathways, and their synergistic interactions during PCB biodegradation, are not well understood. This study investigates BP and BZ biodegradation and subsequent carbon flow through the microbial community in PCB-contaminated soil. DNA stable isotope probing (SIP) was used to identify the bacterial guilds involved in utilizing 13C-biphenyl (unchlorinated analogue of PCBs) and/or 13C-benzoate (product/intermediate of BP degradation and analogue of chlorobenzoates). By performing SIP with two substrates in parallel, we reveal microbes performing the upper (BP) and/or lower (BZ) degradation pathways, and heterotrophic bacteria involved indirectly in processing carbon derived from these substrates (i.e. through crossfeeding). Substrate mineralization rates and shifts in relative abundance of labeled taxa suggest that BP and BZ biotransformations were performed by microorganisms with different growth strategies: BZ-associated bacteria were fast growing, potentially copiotrophic organisms, while microbes that transform BP were oligotrophic, slower growing, organisms. Our findings provide novel insight into the functional interactions of soil bacteria active in processing biphenyl and related aromatic compounds in soil, revealing how carbon flows through a bacterial community.

  17. Synthesis, structural, spectroscopic and thermal characteristics of disubstituted biphenyl derivative: Biphenyl-4,4‧-diacetic acid

    Science.gov (United States)

    Sienkiewicz-Gromiuk, Justyna; Głuchowska, Halina; Tarasiuk, Bogdan; Mazur, Liliana; Rzączyńska, Zofia

    2014-07-01

    A novel 4,4‧-disubstituted biphenyl derivative featuring two acetic acid side arms symmetrically attached to a biphenyl system, that is biphenyl-4,4‧-diacetic acid (H2bpda), has been successfully synthesized by means of the three-stage organic strategy. The synthesis product was characterized by elemental analysis, various spectroscopic techniques including FT-IR, Raman, 1H and 13C NMR as well as thermogravimetric and TG-FT-IR coupled measurements. The phase purity of material was verified on the basis of the X-ray powder diffraction. The studied compound crystallizes in the monoclinic P21/c space group with half of the molecule in the asymmetric unit. Structural studies indicate intermolecular Osbnd H⋯O hydrogen bonding between the carboxylic groups of the adjacent molecules of H2bpda. The occurrence of intermolecularly associated carboxylic groups can also be clearly seen in the vibrational spectra of the acid. On thermal analysis both in air and nitrogen an anhydrous compound demonstrates considerable thermal stability.

  18. the Study of Hepatitis B Virus Reactivation

    Institute of Scientific and Technical Information of China (English)

    Zhao-chun Chi

    2014-01-01

    Hepatitis B virus (HBV) reactivation after chemotherapy or immunosuppressive therapy is a cause of liver-related morbidity and mortality. Not all chronic hepatitis B patients will lead to HBV reactivation. The incidence is 0.3%-30.2%according to the reports. The mechanism of HBV reactivation is still unclear, but it is believed that the viral load is increasing due to the suppression of immune response. No uniform diagnostic criteria are available. HBV reactivation can be confirmed by an increase of serum HBV DNA level. Recently, awareness of reactivation of occult HBV has been improved, especially in HBV endemic area. Preemptive antiviral therapy was the best approach to prevent the HBV reactivation. HBV reactivation can lead to acute hepatitis, severe hepatitis and acute liver failure. Therefore, it is worthy of great attention and further study. Antiviral therapy is safe and effective to prevent HBV reactivation.

  19. A Tariff for Reactive Power

    Energy Technology Data Exchange (ETDEWEB)

    Kueck, John D [ORNL; Kirby, Brendan J [ORNL; Li, Fangxing [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator

    2008-07-01

    Two kinds of power are required to operate an electric power system: real power, measured in watts, and reactive power, measured in volt-amperes reactive or VARs. Reactive power supply is one of a class of power system reliability services collectively known as ancillary services, and is essential for the reliable operation of the bulk power system. Reactive power flows when current leads or lags behind voltage. Typically, the current in a distribution system lags behind voltage because of inductive loads such as motors. Reactive power flow wastes energy and capacity and causes voltage droop. To correct lagging power flow, leading reactive power (current leading voltage) is supplied to bring the current into phase with voltage. When the current is in phase with voltage, there is a reduction in system losses, an increase in system capacity, and a rise in voltage. Reactive power can be supplied from either static or dynamic VAR sources. Static sources are typically transmission and distribution equipment, such as capacitors at substations, and their cost has historically been included in the revenue requirement of the transmission operator (TO), and recovered through cost-of-service rates. By contrast, dynamic sources are typically generators capable of producing variable levels of reactive power by automatically controlling the generator to regulate voltage. Transmission system devices such as synchronous condensers can also provide dynamic reactive power. A class of solid state devices (called flexible AC transmission system devices or FACTs) can provide dynamic reactive power. One specific device has the unfortunate name of static VAR compensator (SVC), where 'static' refers to the solid state nature of the device (it does not include rotating equipment) and not to the production of static reactive power. Dynamic sources at the distribution level, while more costly would be very useful in helping to regulate local voltage. Local voltage regulation would

  20. Bioaccumulation of hydroxylated polychlorinated biphenyls and pentachlorophenol in the serum of northern elephant seal pups (Mirounga angustirostris)

    OpenAIRE

    Louis, Caroline; Covaci, Adrian; Stas, Marie; Crocker, Daniel; Malarvannan, Govindan; Dirtu, Alin; Debier, Cathy

    2015-01-01

    Northern elephant seals (NES) (Mirounga angustirostris) from the Año Nuevo State Reserve (CA, USA) were sampled at 1-, 4-, 7- and 10-week post-weaning. Concentrations of hydroxylated polychlorinated biphenyls (HO-PCBs) and their parent PCBs were measured in the serum of each individual. The ΣHO-PCB concentrations in the serum increased significantly between early and late fast (from 282±20 to 529±31 pg/mL). This increase might result from a mobilisation of HO-PCBs transferred from the mother ...

  1. Particle-Dissolved Phase Partition of Polychlorinated Biphenyls in High Altitude Alpine Lakes.

    Science.gov (United States)

    Nellier, Yann-Michel; Perga, Marie-Elodie; Cottin, Nathalie; Fanget, Philippe; Naffrechoux, Emmanuel

    2015-08-18

    We investigated whether polychlorinated biphenyls (PCBs) partitioning between the dissolved and particulate phases in two high altitude alpine lakes was determined by the quantity, size structure, or composition of suspended particles. Within- and between-lakes differences in water-particulate phase partition coefficient (Kp) were not related to total suspended matter, phytoplankton biomass, or taxonomic composition. Yet, a seasonal relationship between Kp and Kow was detected for both lakes, revealing equilibrium of PCBs partition when lakes were ice covered. On the contrary, PCBs partitioning between particles and water appeared kinetically limited during the open water season. Partition is therefore mainly governed by thermodynamic laws during the ice-covered period, while none of the tested physical or biological parameters seemed to explain the distribution of these particle-reactive contaminants in the open water period. PCBs were always mainly associated with particulate matter, but partitioning within different particulate size-fractions varied between seasons and between years during open water periods. When ice cover is absent, PCBs were mainly adsorbed on microplankton, the largest phytoplanktonic size fraction, which is the least likely to get grazed by pelagic microconsumers. PMID:26189929

  2. Red Blood Cell Docosapentaenoic Acid (DPA n-3 is Inversely Associated with Triglycerides and C-reactive Protein (CRP in Healthy Adults and Dose-Dependently Increases Following n-3 Fatty Acid Supplementation

    Directory of Open Access Journals (Sweden)

    Ann C. Skulas-Ray

    2015-08-01

    Full Text Available The role of the long-chain omega-3 (n-3 fatty acids eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA in lipid metabolism and inflammation has been extensively studied; however, little is known about the relationship between docosapentaenoic acid (DPA, 22:5 n-3 and inflammation and triglycerides (TG. We evaluated whether n-3 DPA content of red blood cells (RBC was associated with markers of inflammation (interleukin-6 (IL-6, tumor necrosis factor α (TNF-α, and C-reactive protein (CRP and fasting TG prior to n-3 supplementation in two studies (Study 1: n = 115, aged 20–44 years, body mass index (BMI 20–30 kg/m2, TG = 34–176 mg/dL; Study 2: n = 28, aged 22–65 years, BMI 24–37 kg/m2, TG = 141–339 mg/dL. We also characterized the dose-response effects of n-3 fatty acid supplementation on RBC n-3 DPA after five months of supplementation with fish oil (Study 1: 0, 300, 600, 900, and 1800 mg/day EPA + DHA and eight weeks of prescription n-3 ethyl esters (Study 2: 0, 850, and 3400 mg/day EPA + DHA. In Study 1, RBC n-3 DPA was inversely correlated with CRP (R2 = 36%, p < 0.001 and with fasting TG (r = −0.30, p = 0.001. The latter finding was replicated in Study 2 (r = −0.33, p = 0.04. In both studies, n-3 supplementation significantly increased RBC n-3 DPA dose-dependently. Relative increases were greater for Study 1, with increases of 29%–61% vs. 14%–26% for Study 2. The associations between RBC n-3 DPA, CRP, and fasting TG may have important implications for the prevention of atherosclerosis and chronic inflammatory diseases and warrant further study.

  3. Plasma polychlorinated biphenyls in residents of 91 PCB-contaminated and 108 non-contaminated dwellings

    DEFF Research Database (Denmark)

    Meyer, Harald William; Frederiksen, Marie; Göen, Thomas;

    2013-01-01

    In the1950s-1970s polychlorinated biphenyls (PCBs) were used in several countries as plasticizers in elastic sealants in buildings.......In the1950s-1970s polychlorinated biphenyls (PCBs) were used in several countries as plasticizers in elastic sealants in buildings....

  4. Health and productivity of dairy cows fed polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Willett, L.B.; Liu, T.T.; Durst, H.I.; Smith, K.L.; Redman, D.R.

    1987-07-01

    Holstein cows were studied through a complete lactation, a nonlactating period, and 42 days of a subsequent lactation for overt and subtle responses to a commercial mixture of polychlorinated biphenyls. Dosed cows (n = 4) received consecutive 60-day periods of daily dosing with 10, 100, and 1000 mg of Aroclor 1254. Control cows (n = 6) received daily sham doses. The following were recorded: daily milk production, feed intake, and health observations; weekly body weight, temperature, heart and respiratory rates and rectal palpation; semi-monthly clinical chemistry determinations; and monthly milk fat, microbiological culture of quarter foremilk samples, and composite milk somatic cell counts. Mean daily milk production (22.4 +/- 1.1 vs 24.8 +/- 1.0 kg) and net energy of a complete lactation (1.46 +/- 0.05 vs 1.45 +/- 0.03 Mcal/kg dry matter intake) were not different (p = 0.85) for control and PCB-dosed cows. Milk production during the first 42 days of the subsequent lactation was also similar for control and dosed cows. Occurrences of injuries, dysfunctions, and general infections were not related to polychlorinated biphenyl exposure. Intramammary infections were detected for both lactations with 51 and 32 infections detected in microbiological cultures, respectively, for the control and dosed groups. Environmental pathogens were most frequently isolated from cases of clinically apparent mastitis. The majority of quarter infections detected were due to Corynebacterium bovis. Only one animal (dosed, necropsy revealed left oviduct obstructed) failed to conceive with three to six services required before conception for the other control and dosed cows. Exposure to polychlorinated biphenyls resulting in maximal residues in milk fat, near 100 micrograms/g, had no apparent effect on health and productivity.

  5. Spermatogenic capacity in fertile men with elevated exposure to polychlorinated biphenyls

    DEFF Research Database (Denmark)

    Petersen, Maria Skaalum; Halling, Jónrit; Weihe, Pál;

    2015-01-01

    BACKGROUND: Endocrine disrupting industrial chemicals, such as polychlorinated biphenyls (PCBs), are suspected to adversely affect male reproductive functions. OBJECTIVES: The Faroe Islands community exhibits an unusually wide range of exposures to dietary contaminants, and in this setting we...... examined the possible association between PCB exposure and semen quality and reproductive hormones in fertile Faroese men. METHODS: Participants in this cross-sectional study include 266 proven fertile men residing in the Faroe Islands. PCB levels and hormone profiles were measured in serum samples taken...... at the clinical examination that included semen quality parameters. RESULTS: A significant positive association was seen between serum-PCB and the testosterone/estradiol ratio (p=0.04). In the unadjusted analyses, elevated PCB exposure was associated with increased serum concentrations of SHBG (p=0...

  6. Exposure to 27 polychlorinated biphenyls in the indoor environment of a workplace

    DEFF Research Database (Denmark)

    Pedersen, Ellen Bøtker; Ebbehøj, N E; Göen, T;

    2016-01-01

    PURPOSE: To assess the exposure to a broad-spectrum of polychlorinated biphenyl congeners (PCBs) from the indoor environment through bio-monitoring of people working in a building with PCB-containing materials and elevated PCB levels in the indoor air. METHODS: A cross-sectional study comparing the...... plasma concentration of 27 PCB congeners in 15 people working in a PCB-contaminated building and 30 matched controls. RESULTS: Median concentration of eight low-chlorinated PCB congeners was significantly higher in the exposed than in the control group. The sum of median concentrations of tri + tetra......-chlorinated PCB was almost ten times higher in the exposed group than in the unexposed, and sums of dioxin-like and non-dioxin-like PCB were both relatively increased by 60 % in the exposed group. CONCLUSIONS: The occupational indoor environment may significantly add to PCB exposure, especially to the lower...

  7. Studies on biphenyl disulphonic acid doped polyanilines: Synthesis, characterization and electrochemistry

    Indian Academy of Sciences (India)

    Chepuri R K Rao; R Muthukannan; M Vijayan

    2012-06-01

    In this article, we report on the results obtained for the efforts we made to bring processability to the conducting polyaniline and substituted polyanilines by designing and synthesizing a new disulphonic acid with a biphenyl moiety as spacer group, viz. 4,4'-biphenyldisulphonic acid (BPSA). When doped, the disulphonic acid acts as a spacer group between the polyaniline chains and facilitates increase in solubility and conductivity. The spacing effect is maximized when BPSA is used as doping agent in in situ polymerization reactions. The conductivity of polyaniline doped by BPSA is 4 S/cm and for the substituted polyanilines it ranged from 2 × 10-5 to 8 × 10-4 S/cm.

  8. Polychlorinated biphenyl concentrations in adipose tissue and abdominal obesity in the elderly

    DEFF Research Database (Denmark)

    Bräuner, Elvira; Raaschou-Nielsen, Ole; Andersen, Zorana;

    2013-01-01

    cessation of smoking, but these do not fully explain the epidemic. Polychlorinated biphenyl congeners (PCBs) are endocrine-disrupting chemicals and evidence from animal experiments suggests an association with obesity development. Our knowledge of the effects of these compounds on weight gain in humans is...... PCBs as potential determinants of abdominal obesity. Adipose tissue was collected upon enrolment and PCBs were quantified using gas chromatography-mass spectroscopy. Median levels of the included PCBs were lower in women, except for PCB118 and all PCBs were positively associated with increased...... abdominal circumference, although this association was not significant. These data indicate a positive link between PCBs and obesity. More work is needed to fully elucidate the complex role of compounds such as PCBs in the present obesity epidemic....

  9. Polychlorinated biphenyl exposure and effects in transformer repair workers.

    OpenAIRE

    Emmett, E A

    1985-01-01

    Fifty-five present and past transformer repair workers exposed to polychlorinated biphenyls (PCBs) and 56 unexposed comparison workers were evaluated in a clinical-epidemiologic study. The groups were similar in most demographic variables. Adipose tissue lipid and serum PCBs concentrations were higher in current exposed workers (geometric means adipose 2.1 ppm, serum 12.2 ppb). Concentrations in comparison (0.6 ppm and 4.6 ppb) and previously exposed (0.83 ppm and 5.9 ppb) workers were lower....

  10. Half-life of polybrominated biphenyl in human sera.

    OpenAIRE

    Rosen, D H; Flanders, W. D.; Friede, A.; Humphrey, H E; Sinks, T H

    1995-01-01

    Polybrominated biphenyl (PBB), a flame-retardant material, was introduced into the food chain in Michigan in 1973 due to a manufacturing and distribution mistake. Following public concern about the long-term health effects of PBB in humans, a cohort of PBB-exposed Michigan residents was assembled in 1975. We initiated this study to determine the half-life of PBB in human sera and to understand how continued body burden relates to the possible adverse health consequences of PBB exposure. To de...

  11. Isolation and characteristics of a novel biphenyl-degrading bacterial strain, Dyella ginsengisoli LA-4

    Institute of Scientific and Technical Information of China (English)

    LI Ang; QU Yuanyuan; ZHOU Jiti; GOU Min

    2009-01-01

    A novel biphenyl-degrading bacterial strain LA-4 was isolated from activated sludge. It was identified as Dyella ginsengisoli according to phylogenetic similarity of 16S rRNA gene sequence. This isolate could utilize biphenyl as sole source of carbon and energy, which degraded over 95 mg/L biphenyl within 36 h. The major metabolites formed from biphenyl, such as 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid (HOPDA) and benzoic acid, were identified by LC-MS. The crude cell extract of strain LA-4 exhibited the activity of 2,3-dihydroxybiphenyl 1,2-dioxygenase (2,3-DHBD) and the kinetic parameters were Km= 26.48 μmol/L and Vmax= 8.12 μmol/mg protein. A conserved region of the biphenyl dioxygenase gene bphA1 of strain LA-4 was amplified by PCR and confirmed by DNA sequencing.

  12. Synthesis and Properties of a Novel Polyimide with Side Chain Containing Biphenyl Unit

    Institute of Scientific and Technical Information of China (English)

    WANG Xu; CHANG Tong-xin; ZHANG Peng; CHEN Yi; LIU Xiang-yang

    2012-01-01

    A novel biphenyl side-chained diamine with alkyloxy spacer and alkyloxy tail,4'-butoxy-4-(3,5-diami-nobenzoyloxy)hexyloxybiphenyl(C6BBC4),was synthesized and characterized by FTIR and 1H NMR.A series of polyimide(PI)films with different side chain contents was synthesized from biphenyltetracarboxylicdianhydride (BPDA),4,4'-oxydianiline(ODA)and C6BBC4,and their thermal properties,optical transparency and liquid crystal alignment property,and so on,were investigated by thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),crystal rotation method,polarizing microscopy and UV-Vis spectra.With the content of side chained diamine increasing from 0 to 100%,the ηinh of poly(amide acid)(PAA)decreased rapidly from 3.0 to 0.51,the glass transition temperature(Tg)of polyimides(PIs)decreased from 274 ℃ to 203 ℃ and the Vis-light transmittance of alignment films substantially increased.As for the alignment properties,the pretilt angle of PI alignment films without rubbing could reach 90° when the content of C6BBC4 was 60% or more.At the same time,the alignment stability could meet the industrial requirements.It was considered that the alkoxy spacer,the biphenyl unit and the alkoxy tail may all play important roles in achieving a large pretilt angle even up to 90°,and the introduction of only the alkoxy spacer or alkoxy tail can also improve the pretilt angle,but not by much.

  13. Polychlorinated biphenyls (PCBs) in a river ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Bremle, G.

    1997-03-01

    In the Emaan River, in southeast Sweden, contaminated sediment was a source of PCB, the largest deposits of it being found in a small lake connected to the river: lake Jaernsjoen, the sediment of which contained about 400 kg of PCB. The concentration of PCB in the water and in the fish was more elevated downstream from the lake than at upstream sites. Lake Jaernsjoen was cleaned up by dredging during 1993 and 1994. The dredged sediment, estimated to contain over 95% of the PCB in the lake, was deposited in a landfill. During the cleanup action, the concentration of PCB downstream from the lake did not become higher than before. The PCB concentration in the air around the landfill increased in the vicinity and during construction of the landfill. After closure of the landfill by a layer placed on top of it, the PCB concentration in the air fell to background levels. No increase in the PCB concentration in the ground water around the landfill as a result of the remedial action could be detected. In the summer of 1996, nearly two years after remediation had been completed, an investigation of the PCB concentration in the fish of the river system was conducted. This investigation was a repetition of one made in 1991, prior to remediation. It showed that after remediation the concentration of PCB in one-year old fish in Lake Jaernsjoen was halved. The concentration of PCB in fish upstream was also lower, probably because of the decrease in overall background contamination. 155 refs, 13 figs

  14. Multifunctional reactive nanocomposite materials

    Science.gov (United States)

    Stamatis, Demitrios

    Many multifunctional nanocomposite materials have been developed for use in propellants, explosives, pyrotechnics, and reactive structures. These materials exhibit high reaction rates due to their developed reaction interfacial area. Two applications addressed in this work include nanocomposite powders prepared by arrested reactive milling (ARM) for burn rate modifiers and reactive structures. In burn rate modifiers, addition of reactive nanocomposite powders to aluminized propellants increases the burn rate of aluminum and thus the overall reaction rate of an energetic formulation. Replacing only a small fraction of aluminum by 8Al·MoO3 and 2B·Ti nanocomposite powders enhances the reaction rate with little change to the thermodynamic performance of the formulation; both the rate of pressure rise and maximum pressure measured in the constant volume explosion test increase. For reactive structures, nanocomposite powders with bulk compositions of 8Al·MoO3, 12Al·MoO3, and 8Al·3CuO were prepared by ARM and consolidated using a uniaxial die. Consolidated samples had densities greater than 90% of theoretical maximum density while maintaining their high reactivity. Pellets prepared using 8Al·MoO3 powders were ignited by a CO2 laser. Ignition delays increased at lower laser powers and greater pellet densities. A simplified numerical model describing heating and thermal initiation of the reactive pellets predicted adequately the observed effects of both laser power and pellet density on the measured ignition delays. To investigate the reaction mechanisms in nanocomposite thermites, two types of nanocomposite reactive materials with the same bulk compositions 8Al·MoO3 were prepared by different methods. One of the materials was manufactured by ARM and the other, so called metastable interstitial composite (MIC), by mixing of nano-scaled individual powders. Clear differences in the low-temperature redox reactions, welldetectable by differential scanning calorimetry

  15. Extraction equilibria of trimellitic and [1,1'-Biphenyl]-2,2'-dicarboxylic Acid with 1-Octanol, 50%TBP, and 10%TRPO in Kerosene%正辛醇、50%TBP/煤油和10%TRPO/煤油对偏苯三甲酸和2,2'-联苯二甲酸的萃取平衡

    Institute of Scientific and Technical Information of China (English)

    周智勇; 秦炜; 戴猷元

    2008-01-01

    To explore the feasibility of extracting aromatic acid products from oxidizing coal, two aromatic acids, trimellitic and [1,1'-biphenyl]-2,2'-dicarboxylic acid, were selected as the solutes, and the extraction equilibrium of the acids were studied with 1-octanol, 50% tributyl phosphate (TBP) in kerosene, and 10% trialkylphosphine oxide (TRPO) in kerosene. The results showed that the degree of extraction of [1,1'-biphenyl]-2,2'-dicarboxylic acid was larger than that of trimellitic acid for all of the solvent, and the extraction capacity with TRPO is more effective than the one with TBP. The extraction behavior of aromatic polyacid is different from that of carboxylic acid, and the reactive extraction function of aromatic acids with TBP and TRPO is not as effective as that of carboxylic acid. 1-octanol could be used to remove [1,1'-biphenyl]-2,2'-dicarboxylic acid from the mixture of trimellitic acid and [1,1'-biphenyl]-2,2'-dicarboxylic acid. Because the weak hydrogen bond association exists between -OH in 1-octanol and -COOH in aromatic acid, the extractive selectivity of [1,1'-biphenyl]-2,2'-dicarboxylic to trimellitic acid depends on the stoichiometric ratio.

  16. Therapeutic reactive oxygen generation.

    Science.gov (United States)

    Scharff, Peter; Ritter, Uwe; Matyshevska, Olga P; Prylutska, Svitlana V; Grynyuk, Iryna I; Golub, Alexandr A; Prylutskyy, Yuriy I; Burlaka, Anatoliy P

    2008-01-01

    An increase of the intracellular reactive oxygen species (ROS) concentration leads to the development of oxidative stress and, thus, to the damage of cell components. The cause-and-effect relations between these processes have not been fully established yet. The ability of photo excited supramolecular composites containing fullerenes C60 immobilized at nanosilica particles to generate reactive oxygen species (ROS) in cells of two types (rat thymocytes, and transformed cells of ascite Erlich carcinoma, EAC, and leucosis L1210) is demonstrated. The damaging effect of photo excited C60-composites are shown, which appeared to be selective and manifested in transformed cells, but not in thymocytes. It has been shown that after the irradiation of aqueous solutions or cell suspensions in the presence of fullerene C60, the generation of reactive oxygen species is observed. It has been shown that the influence of photo excited fullerene C60 on metabolic processes depends on the composition of C60-containing complex and on the type of the cells. The damaging effects of photo excited fullerene C60-containing composites were demonstrated to be selective. The data presented suggest that the application of fullerene C60-containing composites for the selective activation of ROS-dependent death program in certain types of tumor cells is very promising. PMID:18564617

  17. Menstrual function among women exposed to polybrominated biphenyls: A follow-up prevalence study

    Directory of Open Access Journals (Sweden)

    Cameron Lorraine L

    2005-08-01

    Full Text Available Abstract Background Alteration in menstrual cycle function is suggested among rhesus monkeys and humans exposed to polybrominated biphenyls (PBBs and structurally similar polychlorinated biphenyls (PCBs. The feedback system for menstrual cycle function potentially allows multiple pathways for disruption directly through the hypothalamic-pituitary-ovarian axis and indirectly through alternative neuroendocrine axes. Methods The Michigan Female Health Study was conducted during 1997–1998 among women in a cohort exposed to PBBs in 1973. This study included 337 women with self-reported menstrual cycles of 20–35 days (age range: 24–56 years. Current PBB levels were estimated by exponential decay modeling of serum PBB levels collected from 1976–1987 during enrollment in the Michigan PBB cohort. Linear regression models for menstrual cycle length and the logarithm of bleed length used estimated current PBB exposure or enrollment PBB exposure categorized in tertiles, and for the upper decile. All models were adjusted for serum PCB levels, age, body mass index, history of at least 10% weight loss in the past year, physical activity, smoking, education, and household income. Results Higher levels of physical activity were associated with shorter bleed length, and increasing age was associated with shorter cycle length. Although no overall association was found between PBB exposure and menstrual cycle characteristics, a significant interaction between PBB exposures with past year weight loss was found. Longer bleed length and shorter cycle length were associated with higher PBB exposure among women with past year weight loss. Conclusion This study suggests that PBB exposure may impact ovarian function as indicated by menstrual cycle length and bleed length. However, these associations were found among the small number of women with recent weight loss suggesting either a chance finding or that mobilization of PBBs from lipid stores may be important

  18. Reactive power compensation a practical guide

    CERN Document Server

    Hofmann, Wolfgang; Just, Wolfgang

    2012-01-01

    The comprehensive resource on reactive power compensation, presenting the design, application and operation of reactive power equipment and installations The area of reactive power compensation is gaining increasing importance worldwide. If suitably designed, it is capable of improving voltage quality significantly, meaning that losses in equipment and power systems are reduced, the permissible loading of equipment can be increased, and the over-all stability of system operation improved. Ultimately, energy use and CO2 emisson are reduced. This unique guide discusses the

  19. Polychlorinated biphenyls, glycaemia and diabetes in a population living in a highly polychlorinated biphenyls-polluted area in northern Italy: a cross-sectional and cohort study

    Directory of Open Access Journals (Sweden)

    Claudia Zani

    2013-05-01

    Full Text Available Background. Polychlorinated biphenyls (PCBs have been found to be associated with diabetes in some, but not all, studies performed so far. The aim of this study was to assess the association between PCB serum levels and glycaemia and diabetes in people living in Brescia, a highly industrialised PCB-polluted town in Northern Italy. Design and Methods. 527 subjects were enrolled in a cross-sectional population-based study: they were interviewed face-to-face in 2003 and also provided a blood sample under fasting conditions. The concentration of 24 PCB congeners was determined using gas-chromatography (GC/MS. Subsequently, all subjects were included in a follow-up (cohort study. According to the Local Health Authority health-care database, subjects were considered to be diabetic if they had diabetes at interview time (prevalent cases or during a 7-year follow-up (incident cases. Results. A total of 53 subjects (10.0% were diabetics: 28 had dia- betes at enrolment and other 25 developed the disease subsequently. Diabetes frequency increased according to the serum concentrations of total PCBs and single PCB congeners, but no association was found when estimates were adjusted for education, body mass index, age and gender by logistic regression analysis. Accordingly, glycaemia increased with PCB serum levels, but no association was observed when multiple regression analysis, including confounding factors, was performed. Conclusions. This study does not support the hypothesis that PCB environmental exposure is strictly associated with diabetes or glycaemia.

  20. Impact of size and sorption on degradation of trichloroethylene and polychlorinated biphenyls by nano-scale zerovalent iron

    International Nuclear Information System (INIS)

    Highlights: ► nZVIs were synthesized using a layer-by-layer or poly(acrylic acid) stabilization approach. ► These nZVIs were used to degrade TCE and PCB. ► nZVI coatings impacted reactivity by altering pollutants/particle interactions. ► Smaller nZVI particle size led to greater reactivity. - Abstract: Nano-scale zerovalent iron (nZVI) has been studied in recent years for environmental remediation applications such as the degradation of chlorinated organic contaminants. To overcome limitations related to the transport of nZVI, it is becoming common to add a polymer stabilizer to limit aggregation and enhance the particle reactivity. Another method investigated to enhance particle reactivity has been to limit particle size through novel synthesis techniques. However, the relative impacts of particle size and interactions of the chemicals with the coatings are not yet well understood. The purpose of this study was to investigate the mechanisms of particle size and polymer coating or polyelectrolyte multilayer (PEM) synthesis conditions on degradation of two common chlorinated contaminants: trichloroethylene (TCE) and polychlorinated biphenyls (PCBs). This was accomplished using two different synthesis techniques, a layer-by-layer approach at different pH values or iron reduction in the presence of varying concentrations of poly(acrylic acid). nZVI produced by both techniques yielded higher degradation rates than a traditional approach. The mechanistic investigation indicated that hydrophobicity and sorption to the multilayer impacts the availability of the hydrophobic compound to the nZVI and that particle size also had a large role with smaller particles having stronger dechlorination rates.

  1. Effects of Polychlorinated Biphenyl Congener Concentration and Sediment Supplementation on Rates of Methanogenesis and 2,3,6-Trichlorobiphenyl Dechlorination in an Anaerobic Enrichment

    OpenAIRE

    Boyle, Alfred W.; Blake, Cheryl K.; Price, W. Allen; May, Harold D.

    1993-01-01

    We have employed a method of enrichment that allows us to significantly increase the rate of reductive polychlorinated biphenyl (PCB) dechlorination. This method shortens the time required to investigate the effects that culture conditions have on dechlorination and provides an estimate of the potential activity of the PCB-dechlorinating anaerobes. The periodic supplementation of sterile sediment and PCB produced an enhanced, measurable, and sustained rate of dechlorination. We observed volum...

  2. The contraction induced increase in gene expression of peroxisome proliferator-activated receptor (PPAR)-gamma coactivator 1alpha (PGC-1alpha), mitochondrial uncoupling protein 3 (UCP3) and hexokinase II (HKII) in primary rat skeletal muscle cells is dependent on reactive oxygen species

    DEFF Research Database (Denmark)

    Silveira, Leonardo R.; Pilegaard, Henriette; Kusuhara, Keiko; Curi, Rui; Hellsten, Ylva

    2006-01-01

    We evaluated the role of reactive oxygen species (ROS) for the contraction induced increase in expression of PGC-1alpha, HKII and UCP3 mRNA. Rat skeletal muscle cells were subjected to acute or repeated electrostimulation in the presence and absence of antioxidants. Contraction of muscle cells lead...

  3. Preparation and characterization of thermally stable copoly(phthalazinone biphenyl ether sulfone) hollow fiber ultrafiltration membranes

    Science.gov (United States)

    Liu, Peng; Zhang, Shouhai; Wang, Yutian; Lu, Yan; Jian, Xigao

    2015-04-01

    Novel thermally stable copoly(phthalazinone biphenyl ether sulfone) (PPBES) hollow fiber ultrafiltration (UF) membranes were successfully fabricated by the dry/wet phase inversion technique. The effects of polymer dope formulation (i.e., the PPBES concentration, different types and contents of additives) and fiber spinning conditions (i.e., air gap distance, coagulation bath temperature) on the morphologies and separation performance of PPBES hollow fiber UF membranes were investigated, respectively. It was found that the water flux of hollow fiber membrane decreased with the increase of PPBES concentration or EGME content in casting solution, while the rejection of PEG increased. However, the PPBES hollow fiber UF prepared with LiCl as inorganic small molecule additive exhibited different phenomena. In addition, the decrease of air gap distance or the increase of coagulation bath temperature could improve the water flux of UF membrane while reduce the rejection of PEG. Moreover, the thermal stability of the PPBES hollow fiber UF membranes was investigated. The water flux of PPBES membrane increased dramatically from 155 to 428 L m-2 h-1 without significant decrease of rejection when the temperature of feed solution increased from 20 °C to 95 °C.

  4. Mathematical modeling of human dietary exposure to polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Adamov, J.; Vojinovic-Miloradov, M.; Jovetic, S.; Buzarov, D. [Univ. of Novi Sad, Chemistry Dept. (Czechoslovakia)

    2004-09-15

    In this paper a mathematical model for human dietary exposure to polychlorinated biphenyls is postulated, based on the calculation of human exposure factors to PCBs via different members of the terrestrial food chain. On the basis of postulated model and experimental values for the atmospheric and soil concentration of PCBs it is possible to calculate the average daily exposure of a human organism to these ubiquitous environmental toxicants, which represent a constant threat to human health due to various chronic, developmental and genetic effects. Proposed model is the contribution to the development of exposure analysis, which is a part of a complex process of risk assessment, which gains its importance in the current situation of rapid development of industry and technology and the existence of innumerable anthropogenic hazardous chemicals.

  5. Vapor solvent decontamination of PCB [polychlorinated biphenyls] transformer components

    International Nuclear Information System (INIS)

    A process is provided to recover reclaimable material from discarded transformers containing PCB (polychlorinated biphenyl) insulating oils and to minimize the volume of materials which are subject to environmental regulation upon disposal. According to the invention, the transformer is drained and given an initial cleaning. The internal parts are removed and cleaned a second time as is the empty transformer casing. Recoverable materials such as aluminum and copper are cleaned to less than 10 μg of PCB per 100 cm2, allowing these materials to be recycled rather than buried. Almost all of the remaining nonmetallic materials are combustible solids or liquids which can be destroyed by incineration. The cleaning is accomplished using trichloroethylene solvent, chosen for its low boiling point which makes it easy to recycle using an isothermal separator. The removed transformer parts are cleaned in a secondary cleaning station consisting of 3 separate sections including tumbling baskets. 2 figs

  6. Classical molecular dynamics investigations of biphenyl-based carbon nanomembranes

    Directory of Open Access Journals (Sweden)

    Andreas Mrugalla

    2014-06-01

    Full Text Available Background: Free-standing carbon nanomembranes (CNM with molecular thickness and macroscopic size are fascinating objects both for fundamental reasons and for applications in nanotechnology. Although being made from simple and identical precursors their internal structure is not fully known and hard to simulate due to the large system size that is necessary to draw definite conclusions.Results: We performed large-scale classical molecular dynamics investigations of biphenyl-based carbon nanomembranes. We show that one-dimensional graphene-like stripes constitute a highly symmetric quasi one-dimensional energetically favorable ground state. This state does not cross-link. Instead cross-linked structures are formed from highly excited precursors with a sufficient amount of broken phenyls.Conclusion: The internal structure of the CNM is very likely described by a disordered metastable state which is formed in the energetic initial process of electron irradiation and depends on the process of relaxation into the sheet phase.

  7. Guidance on the management of polychlorinated biphenyls (PCBs)

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    Polychlorinated biphenyls (PCBs) are a class of synthetic organic chemicals including 209 known isomers, each with from 1 to 10 chlorine atoms on a biphenyl ring. PCBs have a number of desirable properties for industrial applications including thermal stability, flame retardance, and low vapor pressure. Because of these properties, PCBs were widely used as dielectric fluid in electrical equipment such as utility transformers and capacitors. PCBs were also extensively used in hydraulic fluid and heat transfer fluid, in gaskets, as additives in cutting oils and lubricant, and in a variety of other uses. The Toxic Substances Control Act (TSCA) banned the manufacture of PCBs after 1978 in response to emerging information about the adverse health effects of PCBs and their persistence in the environment. In addition, TSCA directed the Administrator of the Environmental Protection Agency (EPA) to prescribe methods for disposal of PCBS, require marking of PCBs with warning labels, and control their use. The TSCA regulations allow continued use of PCBs provided that the use is totally enclosed and does not pose a risk to human health or the environment. However, at the end of their useful life, all PCB materials must be disposed of according to the TSCA regulations. This guidance document uses graphics and flow charts where possible to present the TSCA regulations according to management activities such as use, storage, disposal, and spill cleanup. The document is designed to be read on an as-needed basis; that is, each chapter can stand alone or may be read in combination with others to help the reader determine the regulations relevant to his or her individual situation and needs. Every attempt has been made to include the requirements of other statutes and regulations that apply to PCB materials and provide references for the reader to consult for additional information.

  8. Reactive Kripke semantics

    CERN Document Server

    Gabbay, Dov M

    2013-01-01

    This text offers an extension to the traditional Kripke semantics for non-classical logics by adding the notion of reactivity. Reactive Kripke models change their accessibility relation as we progress in the evaluation process of formulas in the model. This feature makes the reactive Kripke semantics strictly stronger and more applicable than the traditional one. Here we investigate the properties and axiomatisations of this new and most effective semantics, and we offer a wide landscape of applications of the idea of reactivity. Applied topics include reactive automata, reactive grammars, rea

  9. The reactive extrusion of thermoplastic polyurethane

    OpenAIRE

    Verhoeven, Vincent Wilhelmus Andreas

    2006-01-01

    The objective of this thesis was to increase the understanding of the reactive extrusion of thermoplastic polyurethane. Overall, several issues were identified: • Using a relative simple extrusion model, the reactive extrusion process can be described. This model can be used to further investigate and optimize the reactive extrusion of thermoplastic polyurethane. • Premixing has a small beneficiary effect on the efficiency of the extrusion process and the quality of the product formed. • The ...

  10. Uptake of polychlorinated biphenyls and organochlorine pesticides from soil and air into radishes (Raphanus sativus)

    DEFF Research Database (Denmark)

    Mikes, Ondrej; Cupr, P.; Trapp, Stefan;

    2009-01-01

    Uptake of organochlorine pesticides and polychlorinated biphenyls from soil and air into radishes was measured at a heavily contaminated field site. The highest contaminant concentrations were found for DDT and its metabolites, and for beta-hexachlorocyclohexane. Bioconcentration factor (BCF...

  11. COMPARING POLYCHLORINATED BIPHENYLS IN FARM-RAISED AND WILD-CAUGHT CATFISH FROM SOUTHERN MISSISSIPPI

    Science.gov (United States)

    Polychlorinated biphenyls (PCBs) are among the most thermally stable organic chemicals known. This characteristic has historically made them useful in a wide array of applications including use in electrical transformers and capacitors, varnishes, waxes, synthetic resins, epoxy ...

  12. Polychlorinated biphenyl (PCB) removal from the Kenai National Wildlife Refuge, Alaska, October 1984 and 1988

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the removal of polychlorinated biphenyl PCB from Kenai National Wildlife Refuge in Alaska during October 1984 and 1985. Atlantic Ritchfield...

  13. METHODS FOR DETERMINING THE POLYCHLORINATED BIPHENYL EMISSIONS FROM INCINERATION AND CAPACITOR AND TRANSFORMER FILLING PLANTS

    Science.gov (United States)

    Described are methods to measure the polychlorinated biphenyl (PCB) emissions from the stacks of municipal waste, industrial waste, and sewage sludge incinerators and from capacitor and transformer filling plants. The PCB emissions from the incineration plants are collected by im...

  14. 78 FR 20640 - Polychlorinated Biphenyls (PCBs); Recycling Plastics from Shredder Residue

    Science.gov (United States)

    2013-04-05

    ... Residue (77 FR 74006). Additional background information on recycling activities that would be affected by... AGENCY Polychlorinated Biphenyls (PCBs); Recycling Plastics from Shredder Residue AGENCY: Environmental... will generally allow for the recycling of plastic separated from shredder residue under the...

  15. Immunologic effects of background exposure to polychlorinated biphenyls and dioxins in Dutch preschool children

    NARCIS (Netherlands)

    N. Weisglas-Kuperus (Nynke); S. Patandin (Svati); G.A. Berbers; T.C.J. Sas (Theo); P.J.J. Sauer (Pieter); H. Hooijkaas (Herbert); P.G.H. Mulder (Paul)

    2000-01-01

    textabstractPrenatal exposure to polychlorinated biphenyls (PCBs) and dioxins is associated with changes in the T-cell lymphocyte population in healthy Dutch infants. We investigated whether these changes persist into later childhood and whether background exposure to P

  16. Reactive perforating collagenosis

    Directory of Open Access Journals (Sweden)

    Yadav Mukesh

    2009-01-01

    Full Text Available Reactive perforating collagenosis is a rare cutaneous disorder of unknown etiology. We hereby describe a case of acquired reactive perforating collagenosis in a patient of diabetes and chronic renal failure.

  17. Reactive perforating collagenosis

    OpenAIRE

    Yadav Mukesh; Sangal B; Bhargav Puneet; Jai P; Goyal Mukul

    2009-01-01

    Reactive perforating collagenosis is a rare cutaneous disorder of unknown etiology. We hereby describe a case of acquired reactive perforating collagenosis in a patient of diabetes and chronic renal failure.

  18. Polychlorinated biphenyls (PCBs) and neurological development in children: a systematic review

    OpenAIRE

    Ribas-Fito, N; Sala, M.; Kogevinas, M; Sunyer, J.

    2001-01-01

    BACKGROUND—Polychlorinated biphenyls (PCBs) are complex mixtures of persistent contaminants that are widespread in the environment. Newborns are exposed across the placenta and through breast feeding. Experimental animal studies have indicated that PCBs are neurotoxic. The neurological effects of these compounds on children are not clear. Methods—A systematic review of literature on the relation between neurological development in children and exposure to polychlorinated biphenyls.
RESULTS—Se...

  19. Brominated Biphenyls Prime Extensive Microbial Reductive Dehalogenation of Aroclor 1260 in Housatonic River Sediment

    OpenAIRE

    Bedard, Donna L.; Van Dort, Heidi; DeWeerd, Kim A.

    1998-01-01

    The upper Housatonic River and Woods Pond (Lenox, Mass.), a shallow impoundment on the river, are contaminated with polychlorinated biphenyls (PCBs), the residue of partially dechlorinated Aroclor 1260. Certain PCB congeners have the ability to activate or “prime” anaerobic microorganisms in Woods Pond sediment to reductively dehalogenate the Aroclor 1260 residue. We proposed that brominated biphenyls might have the same effect and tested the priming activities of 14 mono-, di-, and tribromin...

  20. Novel Ring Cleavage Products in the Biotransformation of Biphenyl by the Yeast Trichosporon mucoides

    OpenAIRE

    Sietmann, Rabea; Hammer, Elke; Specht, Michael; Carl E Cerniglia; Schauer, Frieder

    2001-01-01

    The yeast Trichosporon mucoides, grown on either glucose or phenol, was able to transform biphenyl into a variety of mono-, di-, and trihydroxylated derivatives hydroxylated on one or both aromatic rings. While some of these products accumulated in the supernatant as dead end products, the ortho-substituted dihydroxylated biphenyls were substrates for further oxidation and ring fission. These ring fission products were identified by high-performance liquid chromatography, gas chromatography-m...

  1. Directed Evolution of Biphenyl Dioxygenase: Emergence of Enhanced Degradation Capacity for Benzene, Toluene, and Alkylbenzenes

    OpenAIRE

    Suenaga, Hikaru; Mitsuoka, Mariko; Ura, Yuko; Watanabe, Takahito; Furukawa, Kensuke

    2001-01-01

    Biphenyl dioxygenase (Bph Dox) catalyzes the initial oxygenation of biphenyl and related compounds. Bph Dox is a multicomponent enzyme in which a large subunit (encoded by the bphA1 gene) is significantly responsible for substrate specificity. By using the process of DNA shuffling of bphA1 of Pseudomonas pseudoalcaligenes KF707 and Burkholderia cepacia LB400, a number of evolved Bph Dox enzymes were created. Among them, an Escherichia coli clone expressing chimeric Bph Dox exhibited extremely...

  2. Sublethal concentrations of salicylic acid decrease the formation of reactive oxygen species but maintain an increased nitric oxide production in the root apex of the ethylene-insensitive Never ripe tomato mutants

    OpenAIRE

    Tari, Irma; Poór, Péter; Gémes, Katalin

    2011-01-01

    The pattern of salicylic acid (SA)-induced production of reactive oxygen species (ROS) and nitric oxide (NO) were different in the apex of adventitious roots in wild-type and in the ethylene-insensitive Never ripe (Nr) mutants of tomato (Solanum lycopersicum L. cv Ailsa Craig). ROS were upregulated, while NO remained at the control level in apical root tissues of wildtype plants exposed to sublethal concentrations of SA. In contrast, Nr plants expressing a defective ethylene receptor displaye...

  3. Reactivity and neutron dynamics

    International Nuclear Information System (INIS)

    Basing on the results of experiments mad with the full-scale WWER-1000 reactor core the problems of simulating neutron distributed transients, reactivity role in their description and uncertainties connected with reactivity value determination are discussed. Adiabatic approximation application and reactivity insertions lead to multiplicative representation of the solution kinetics equation including amplitude multiplier and form function

  4. Regional analysis of potential polychlorinated biphenyl degrading bacterial strains from China.

    Science.gov (United States)

    Shuai, Jianjun; Yu, Xurun; Zhang, Jing; Xiong, Ai-Sheng; Xiong, Fei

    2016-01-01

    Polychlorinated biphenyls (PCBs), the chlorinated derivatives of biphenyl, are one of the most prevalent, highly toxic and persistent groups of contaminants in the environment. The objective of this study was to investigate the biodegradation of PCBs in northeastern (Heilongjiang Province), northern (Shanxi Province) and eastern China (Shanghai municipality). From these areas, nine soil samples were screened for PCB-degrading bacteria using a functional complementarity method. The genomic 16S rDNA locus was amplified and the products were sequenced to identify the bacterial genera. Seven Pseudomonas strains were selected to compare the capacity of bacteria from different regions to degrade biphenyl by HPLC. Compared to the biphenyl content in controls of 100%, the biphenyl content went down to 3.7% for strain P9-324, 36.3% for P2-11, and 20.0% for the other five strains. These results indicate that a longer processing time led to more degradation of biphenyl. PCB-degrading bacterial strains are distributed differently in different regions of China. PMID:27140507

  5. Effects of quercetin on polychlorinated biphenyls-induced liver injury in rats

    Directory of Open Access Journals (Sweden)

    Cléia Rocha de Oliveira

    2014-05-01

    Full Text Available Introduction: Polychlorinated biphenyls (PCBs, used as pesticides in agriculture, can lead to irreversible injuries in living organisms, particularly in liver. Oxidative stress has been implicated in the liver pathogenesis induced by different molecules, including PCBs. It has been demonstrated that quercetin, an antioxidant flavonoid found in the diet, exhibits a potent antioxidant effect in different liver pathologies. Objective: To evaluate oxidative stress caused by PCBs in liver and the antioxidant activity of quercetin. Methodology: We used male Wistar rats (n = 36, divided in 4 groups: control, quercetin (50 mg/kg/day, PCBs (0.4 ml/kg/day, and rats treated with both PCBs and quercetin. On day 25 blood was collected to assess liver integrity (enzymes AST, ALT and ALP, and liver samples to measure oxidative stress (TBARS, activity of antioxidant enzymes (SOD, CAT, GPx and DNA damage (micronucleus assay, and histological damage. Results: TBARS concentration and SOD activity were significantly higher in PCBs animals as compared to the PCB group receiving quercetin. CAT and GPx decreased in PCBs and increased when quercetin was added. The histological analysis showed damage to hepatocytes in PCBs, but quercetin was able to afford protection against such damage. The micronucleus test showed there was an increase in the production of microclenucleus compared to control, and quercetin was able to reduce this effect. Conclusion: Contamination with PCBs led to increased lipid peroxidation and DNA damage, and the use of antioxidant quercetin was effective in reducing PCBs-induced liver injury.

  6. Fracture Reactivation in Chemically Reactive Rock Systems

    Science.gov (United States)

    Eichhubl, P.; Hooker, J. N.

    2013-12-01

    Reactivation of existing fractures is a fundamental process of brittle failure that controls the nucleation of earthquake ruptures, propagation and linkage of hydraulic fractures in oil and gas production, and the evolution of fault and fracture networks and thus of fluid and heat transport in the upper crust. At depths below 2-3 km, and frequently shallower, brittle processes of fracture growth, linkage, and reactivation compete with chemical processes of fracture sealing by mineral precipitation, with precipitation rates similar to fracture opening rates. We recently found rates of fracture opening in tectonically quiescent settings of 10-20 μm/m.y., rates similar to euhedral quartz precipitation under these conditions. The tendency of existing partially or completely cemented fractures to reactivate will vary depending on strain rate, mineral precipitation kinetics, strength contrast between host rock and fracture cement, stress conditions, degree of fracture infill, and fracture network geometry. Natural fractures in quartzite of the Cambrian Eriboll Formation, NW Scotland, exhibit a complex history of fracture formation and reactivation, with reactivation involving both repeated crack-seal opening-mode failure and shear failure of fractures that formed in opening mode. Fractures are partially to completely sealed with crack-seal or euhedral quartz cement or quartz cement fragmented by shear reactivation. Degree of cementation controls the tendency of fractures for later shear reactivation, to interact elastically with adjacent open fractures, and their intersection behavior. Using kinematic, dynamic, and diagenetic criteria, we determine the sequence of opening-mode fracture formation and later shear reactivation. We find that sheared fracture systems of similar orientation display spatially varying sense of slip We attribute these inconsistent directions of shear reactivation to 1) a heterogeneous stress field in this highly fractured rock unit and 2

  7. POLYCHLORINATED BIPHENYLS (PCBS) AS INITIATING AGENTS IN HEPATOCELLULAR CARCINOMA

    OpenAIRE

    Ludewig, Gabriele; Robertson, Larry W.

    2012-01-01

    PCBs are carcinogens, but for many decades it was assumed that PCBs may not possess initiating activity. Initiation is a process that involves changes in the DNA sequence, often, but not exclusively produced through DNA adduction by a reactive compound or reactive oxygen species (ROS). DNA adducts can be detected by 32P-postlabeling, a method that Dr. Ramesh Gupta co-developed and refined. Today these types of assays together with other mechanistic studies provide convincing evidence that spe...

  8. [Development of Self-assembled Dumbbell-like Fe3O4 Micro/nanomaterial for Application in Thermocatalytic Degradation of Polybrominated Biphenyls].

    Science.gov (United States)

    Huang, Xin-chen; Zong, Gang; Liu, Ye-xuan; Lu, Hui-jie; Li, Qian-qian; Li, Bin-ke; Zhao, Yan-hui; Su, Gui-jin

    2016-02-15

    Polybrominated biphenyls (PBBs) are a group of new persistent organic pollutants, which have high toxicity and long-term bioaccumulation, and cause potential risks to human beings and aquatic ecosystem. Self-assembled dumbbell-like Fe3O4 was synthesized via ethylene-glycol mediated method to degrade PBBs, using BB209 as a model compound. The results showed that the growth process of dumbbell-like Fe3O4 precursor had two stages involving a fast nucleation of amorphous primary particles followed by a slow aggregation and crystallization of primary particles. Dumbbell-like Fe3O4 showed high activity for degradation of BB209 at the reaction time of 30 min with the degradation efficiency of nearly 100% at 300 degrees C. A whole series of nonabromobiphenyl to monobromobiphenyl and biphenyls were detected as the degradation products of BB209 by dumbbell-like Fe3O4, indicating the occurrence of successive hydrodebromination reaction. Furthermore, the amounts of three NoBB isomers followed the order of BB207 > BB208 > BB206, indicating that the reactivity of C--Br of BB209 was in order of meta- > para- > ortho-positions. PMID:27363171

  9. A cohort study of the association between secondary sex ratio and parental exposure to polybrominated biphenyl (PBB and polychlorinated biphenyl (PCB

    Directory of Open Access Journals (Sweden)

    Terrell Metrecia L

    2009-08-01

    Full Text Available Abstract Background Polybrominated biphenyl (PBB, a brominated flame retardant, was accidently mixed into animal feed in Michigan (1973–1974 resulting in human exposure through consumption of contaminated meat, milk and eggs. Beginning in 1976 individuals who consumed contaminated products were enrolled in the Michigan Long-Term PBB Study. This cohort presents a unique opportunity to study the association between parental exposures to PBB and offspring sex ratio. Methods We identified offspring of female PBB cohort participants (born 1975–1988 and obtained electronic birth records for those born in the state of Michigan. We linked this information to parental serum PBB and PCB concentrations collected at enrollment into the cohort. We modeled the odds of a male birth with generalized estimating equations accounting for the non-independence of siblings born to the same parents. We explored potential confounders: parental age and education at offspring's birth, parental body mass index at cohort enrollment, birth order, gestational age and year of offspring's birth. Results The overall proportion of male offspring among 865 live births to cohort mothers was 0.542. This was higher than the national male proportion of 0.514 (binomial test: p = 0.10. When both parents were in the cohort (n = 300, we found increased odds of a male birth with combined parents' enrollment PBB exposure ≥ the median concentrations (3 μg/L for mothers; 6 μg/L for fathers compared to combined parents' PBB exposure Conclusion This study adds to the body of literature on secondary sex ratio and exposure to environmental contaminants. In this population, combined parental exposure to PBBs or PCBs increased the odds of a male birth. Further research is needed to corroborate these findings and shed light on the biological mechanisms by which these types of chemicals may influence the secondary sex ratio.

  10. Biphenyl and Benzoate Metabolism in a Genomic Context: Outlining Genome-Wide Metabolic Networks in Burkholderia xenovorans LB400

    OpenAIRE

    Denef, V. J.; Park, J; Tsoi, T. V.; Rouillard, J.-M.; Zhang, H; Wibbenmeyer, J. A.; Verstraete, W; Gulari, E.; Hashsham, S. A.; Tiedje, J. M.

    2004-01-01

    We designed and successfully implemented the use of in situ-synthesized 45-mer oligonucleotide DNA microarrays (XeoChips) for genome-wide expression profiling of Burkholderia xenovorans LB400, which is among the best aerobic polychlorinated biphenyl degraders known so far. We conducted differential gene expression profiling during exponential growth on succinate, benzoate, and biphenyl as sole carbon sources and investigated the transcriptome of early-stationary-phase cells grown on biphenyl....

  11. Structural insight into the expanded PCB-degrading abilities of a biphenyl dioxygenase obtained by directed evolution

    OpenAIRE

    Kumar, Pravindra; Mohammadi, Mahmood; Viger, Jean-François; Barriault, Diane; Gomez-Gil, Leticia; Eltis, Lindsay D.; Bolin, Jeffrey T.; Sylvestre, Michel

    2010-01-01

    The biphenyl dioxygenase of Burkholderia xenovorans LB400 is a multicomponent Rieske-type oxygenase (RO) that catalyzes the dihydroxylation of biphenyl and many polychlorinated biphenyls (PCBs). The structural bases for the substrate specificity of the enzyme’s oxygenase component (BphAELB400) are largely unknown. BphAEp4, a variant previously obtained through directed evolution, transforms several chlorobiphenyls, including 2,6-dichlorobiphenyl, more efficiently than BphAELB400 yet differs f...

  12. Effects of liver damage induced by polychlorinated biphenyls (PCB) on cadmium metabolism in mice

    International Nuclear Information System (INIS)

    Polychlorinated biphenyls (PCB) were added to the diets of mice at different concentrations. Mice fed these diets were given a sc or oral doses of 109Cd. The uptake and excretion of Cd was followed by whole-body counting. The gastrointestinal absorption of Cd after an oral dose of 109Cd was less in animals fed on 66 ppm PCB diet, compared with a control group, and the body elimination of Cd was faster. In the liver, the amount of Cd was reduced by dietary PCB exposure, after both oral and sc administration of 109Cd, and the data suggest a faster transport of Cd from liver to kidneys in PCB-exposed animals than in controls. The mobilized liver Cd was not quantitatively recovered in the kidneys, thus increased urinary excretion due to PCB exposure may have taken place. Histological examination of the livers revealed a dose-dependent induction of liver changes characterized by centrilobular enlargement of liver cells and centrilobular focal necroses. In four of eight livers from animals fed 200 ppm PCB for 32 weeks there were five liver cell tumors with cytological signs of malignancy. In the control group and in groups fed lower doses of PCB (10-100 ppm) no such tumors were found among 28 animals. The results support observations made with agents inducing acute liver damage, that liver damage increases the rate of redistribution of cadmium from the liver to the kidney

  13. Placental markers of human exposure to polychlorinated biphenyls and polychlorinated dibenzofurans

    International Nuclear Information System (INIS)

    These studies have evaluated biochemical changes in placentae from humans exposed to rice oil contaminated with polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs) in Taiwan. Placentae were obtained from nonsmoking women 4 to 5 years after the exposure had occurred. The exposed individuals ingested approximately 1 to 3 g PCBs and 5 mg PCDFs, and many exhibited symptoms characteristic of PCB poisoning. This disease was termed Yu-Cheng in Chinese. Based on data from experimental animals models, the authors examined a number of parameters in placentae from control and exposed women, including arylhydrocarbon hydroxylase (AHH) activity, cytochrome P-450 isozymes, epidermal growth factor (EGF) receptor binding properties and actions, and Ah receptor. They also quantified concentrations of various PCB and PCDF congeners known to be present in the contaminated rice oil. The results revealed a dramatic elevation in placental AHH activity in samples from PCB/PCDF-exposed women. This increase in enzyme activity was associated with a parallel increase in placental microsomal protein immunochemically related to cytochrome P-450 form 6. EGF receptor-mediated autophosphorylation capacity was significantly diminished in PCB/PCDF placentae, but this effect was not associated with changes in plasma membrane EGF receptor binding properties. Two PCDF congeners were detected in Yu-Cheng placentae but not controls. Several PCBs were also detected in much higher concentrations in Yu-Cheng placentae. Surprisingly, placental concentrations of PCBs correlated better with effects than did the PCDFs. The findings are discussed in relation to the risk assessment process

  14. Assessing ongoing sources of dissolved-phase polychlorinated biphenyls in a contaminated stream.

    Science.gov (United States)

    Dang, Viet D; Walters, David M; Lee, Cindy M

    2013-03-01

    Few studies assess the potential of ongoing sources of "fresh" polychlorinated biphenyls (PCBs) to aquatic systems when direct discharge to the environment has been eliminated. In the present study, the authors used single-layered, low-density polyethylene samplers (PEs) to measure total PCB concentrations, congener profiles, and enantiomeric fractions (EFs) in a contaminated stream and to provide multiple lines of evidence for assessing ongoing inputs of PCB. Concentrations were well above background levels that have been monitored for years. Concentrations significantly increased with distance, the farthest downstream PE concentrations being almost five times greater than those at 79 m downstream of a historical point source. The PCBs in the PEs at 79 m downstream of the contamination source were dominated by low K(OW) congeners, similar to those in the mixture of Aroclors 1016 and 1254 (4:1 v/v) historically released from the former capacitor manufacturer. The only two chiral congeners detected in the PEs downstream were PCBs 91 and 95. The EF values were nonracemic for PCB 91, while the values were either racemic or near racemic for PCB 95. Increased PCB concentrations with distance and a congener composition of predominantly low-weight congeners in the PEs at 79 m downstream of the plant site suggested an ongoing PCB source from the plant site. Chiral signatures suggested aerobic biotransformation of dissolved PCBs but did not shed any light on possible ongoing PCB inputs. PMID:23258773

  15. Assessing ongoing sources of dissolved-phase polychlorinated biphenyls in a contaminated stream

    Science.gov (United States)

    Dang, Viet D.; Walters, David M.; Lee, Cindy M.

    2013-01-01

    Few studies assess the potential of ongoing sources of “fresh” polychlorinated biphenyls (PCBs) to aquatic systems when direct discharge to the environment has been eliminated. In the present study, the authors used single-layered, low-density polyethylene samplers (PEs) to measure total PCB concentrations, congener profiles, and enantiomeric fractions (EFs) in a contaminated stream and to provide multiple lines of evidence for assessing ongoing inputs of PCB. Concentrations were well above background levels that have been monitored for years. Concentrations significantly increased with distance, the farthest downstream PE concentrations being almost five times greater than those at 79 m downstream of a historical point source. The PCBs in the PEs at 79 m downstream of the contamination source were dominated by low KOW congeners, similar to those in the mixture of Aroclors 1016 and 1254 (4:1 v/v) historically released from the former capacitor manufacturer. The only two chiral congeners detected in the PEs downstream were PCBs 91 and 95. The EF values were nonracemic for PCB 91, while the values were either racemic or near racemic for PCB 95. Increased PCB concentrations with distance and a congener composition of predominantly low-weight congeners in the PEs at 79 m downstream of the plant site suggested an ongoing PCB source from the plant site. Chiral signatures suggested aerobic biotransformation of dissolved PCBs but did not shed any light on possible ongoing PCB inputs.

  16. Soil-Air Partitioning of Polychlorinated Biphenyls and Total Dichloro-Diphenyl-Trichloroethanes

    Institute of Scientific and Technical Information of China (English)

    Yaping Zhang; Erping Bi; Honghan Chen

    2014-01-01

    Soil-air partitioning is an important diffusive process that affects the environmental fate of organic compounds and human health. In this review, factors affecting the soil-air partitioning of polychlorinated biphenyls (PCBs) and total dichloro-diphenyl-trichloroethanes (p,p’-and o,p’-isomers of DDT, DDD, and DDE) are discussed. Hydrophobicity is an important factor that influences soil-air partition coefficients (KSA), and its effect can be explained through enthalpy of phase change for soil-air partitioning transfer (ΔHSA). For more hydrophobic compounds, a sharp increase in the KSA of PCBs and organochlorines can be seen in the early aging period. During the aging period, the temperature has a significant effect on the more hydrophobic organic compounds. The content and properties of soil or-ganic matter influence the KSA of the target compounds. Generally, KSA decreases with increasing rela-tive humidity in soils. The linear trend between KSA and temperature (T) changes at 0 °C. Freezing the air or soil in experiments would change the research results. On the basis of factors influencing soil-air partitioning, a multipleparameter (T, organic carbon fraction (fOC), and octanol-air partition coefficient (KOA)) model is put forward to predict the KSA values for PCBs and total DDTs.

  17. Species-specific elimination of polychlorinated biphenyls in estuarine animals and its impact on residue patterns.

    Science.gov (United States)

    Goerke, H; Weber, K

    2001-03-01

    Elimination kinetics of tetra-, penta- and hexachlorobiphenyls (IUPAC Nos. 44, 52, 87, 95, 101, 153) were investigated by laboratory experiments in three species of different phyla: Nereis diversicolor (Polychaeta), Palaemon longirostris (Crustacea) and Platichthys flesus (Pisces). Half-lives were species-specific and structure-dependent. Palaemon longirostris eliminated all components fastest. N. diversicolor was faster than Platichthys flesus except for components 95 and 153. Contrary to the fish species, the two invertebrates contained significant amounts of polar transformation products of No. 52, which had been applied as 14C labelled. Therefore, the faster elimination by Palaemon longirostris and N. diversicolor was assumed to be generally due to increased biotransformation. Elimination was in accordance with polychlorinated biphenyl (PCB) residue patterns obtained from field samples of the species. Congeners with vicinal H atoms in m,p positions were under-represented in Palaemon longirostris and so were congeners with > or = 7 Cl in N. diversicolor, while the PCB residue pattern in Platichthys flesus was similar to that of Clophen A60. By comparing percentages of the experimental congeners in sigma PCB and their elimination half-lives in the three species, it was revealed that residue patterns were also influenced by species-dependent uptake, e.g. feeding habits. Extractable organic matter-based sigma PCB levels increased with trophic levels of the three species. PMID:11468813

  18. Changes in egg composition of American kestrels exposed to dietary polychlorinated biphenyls.

    Science.gov (United States)

    Fernie, K J; Bortolotti, G R; Smits, J E; Wilson, J; Drouillard, K G; Bird, D M

    2000-06-01

    Changes in the quality of eggs of birds exposed to polychlorinated biphenyls (PCBs) have been described, but have never been directly attributed to PCBs. Polychlorinated biphenyl residues in eggs have been associated with reduced reproductive success and embryonic deformities in wild birds. Egg size and composition, specifically the amount of albumen, yolk, and water in an egg, also influence the growth and viability of embryos and hatchlings, and consequently the reproductive success of birds. To deter mine whether PCB exposure of adult birds affected the size and composition of their eggs, 25 pairs of captive American kestrels (Falco sparverius) were fed a mixture of PCB-spiked (1248:1254:1260) food to give an approximate exposure of 7 mg/kg body weight/d, beginning 1 mo prior to pairing, and continuing throughout the courtship, egg-laying, and incubation periods. This dietary level in the adult female kestrels resulted in mean total PCB residues in the eggs of 34.1 microg/g wet weight (geometric mean), which is environmentally relevant. PCB residues in eggs increased with the time of female exposure to the contaminated diet and laying date. Variation in egg size within PCB clutches was significantly greater than within control clutches, although absolute egg mass and volume did not differ markedly by treatment. Only infertile eggs and only one egg per clutch were used for egg composition analysis. Yolks in the PCB-contaminated eggs were heavier, with less wet and dry albumen relative to control eggs. Water content and eggshell thickness were not significantly affected by PCB exposure. These results suggest that eggs from the PCB treatment have relatively more lipid and less protein available for embryonic development. Changes in egg composition were not associated with egg size, lay date, ambient temperature, humidity, or precipitation, which are factors known to affect these variables in bird eggs. The PCB-induced changes in egg composition described here

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

    International Nuclear Information System (INIS)

    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

  20. The internal barriers of rotation for the 209 polychlorinated biphenyls.

    Science.gov (United States)

    Andersson, P L; Haglund, P; Tysklind, M

    1997-01-01

    The internal barrier of rotation (Erot) was calculated for all 209 polychlorinated biphenyls (PCBs) by using a semi-empirical method, viz. the Austin Model 1 (AMI) Hamiltonian. The difference in total energy between a forced planar state and an optimised twisted structure was defined as Erot. The Erot values were in the range of 8.33 to 483 kJ/mol, and were significantly influenced by the number of chlorine atoms in ortho position. An additional structural characteristic of the PCBs influencing Erot of ortho substituted congeners was substitution by chlorine atoms in vicinal meta positions, which is assumed to prevent outward bending of ortho substituents. This so-called buttressing effect contributed with 4 to 31 kJ/mol per added chlorine atom. In conclusion, the internal barrier of rotation, calculated for all 209 PCBs, provides an important structure dependent physico-chemical parameter for multivariate modelling of future quantitative structure-activity and structure-property relationships (QSARs/QSPRs). PMID:19005788

  1. Preconception maternal polychlorinated biphenyl concentrations and the secondary sex ratio

    International Nuclear Information System (INIS)

    The secondary sex ratio is the ratio of male to female live births and historically has ranged from 102 to 106 males to 100 females. Temporal declines have been reported in many countries prompting authors to hypothesize an environmental etiology. Blood specimens were obtained from 99 women aged 24-34 prior to attempting pregnancy and quantified for 76 polychlorinated biphenyl (PCB) congeners using dual column gas chromatography with electron capture detection. Women were prospectively followed until pregnancy or 12 cycles of trying. The odds of a male birth for three PCB groupings (total, estrogenic, anti-estrogenic) controlling for maternal characteristics were estimated using logistic regression. Among the 50 women with live births and PCB data, 26 female and 24 male infants were born (ratio 0.92). After adjusting for age and body mass index, odds of a male birth were elevated among women in the second (OR=1.29) and third (OR=1.48) tertiles of estrogenic PCBs; odds (OR=0.70) were reduced among women in the highest tertile of anti-estrogenic PCBs. All confidence intervals included one. The direction of the odds ratios in this preliminary study varied by PCB groupings, supporting the need to study specific PCB patterns when assessing environmental influences on the secondary sex ratio

  2. A comprehensive approach to actual polychlorinated biphenyls environmental contamination.

    Science.gov (United States)

    Risso, F; Magherini, A; Ottonelli, M; Magi, E; Lottici, S; Maggiolo, S; Garbarino, M; Narizzano, R

    2016-05-01

    Worldwide polychlorinated biphenyls (PCBs) pollution is due to complex mixtures with high number of congeners, making the determination of total PCBs in the environment an open challenge. Because the bulk of PCBs production was made of Aroclor mixtures, this analysis is usually faced by the empirical mixture identification via visual inspection of the chromatogram. However, the identification reliability is questionable, as patterns in real samples are strongly affected by the frequent occurrence of more than one mixture. Our approach is based on the determination of a limited number of congeners chosen to enable objective criteria for Aroclor identification, summing up the advantages of congener-specific analysis with the ones of total PCBs determination. A quantitative relationship is established between congeners and any single mixture, or mixtures combination, leading to the identification of the actual contamination composition. The approach, due to its generality, allows the use of different sets of congeners and any technical mixture, including the non-Aroclor ones. The results confirm that PCB environmental pollution in northern Italy is based on Aroclor. Our methodology represents an important tool to understand the source and fate of the PCBs contamination. PMID:26805927

  3. Organochlorine pesticides and polychlorinated biphenyls in California sea lions

    International Nuclear Information System (INIS)

    Concentrations of polychlorinated biphenyls (PCBs), DDTs, chlordanes, HCHs, hexachlorobenzene (HCB), dieldrin, heptachlor epoxide, tris(4-chlorophenyl)methane (TCPMe), and tris(4-chlorophenyl)methanol (TCPMOH) were measured in the blubber of California sea lions (Zalophus californianus) collected in 2000. DDTs were the most predominant contaminants, followed by PCBs, chlordanes, TCPMe, HCHs, TCPMOH, dieldrin, and heptachlor epoxide. Concentrations of PCBs and DDTs varied from a few μg/g to several hundreds of μg/g on a lipid weight basis. Concentrations of DDTs have declined by an order of magnitude over the last three decades in California sea lions; nevertheless, the measured concentrations of PCBs and DDTs in California sea lions are still some of the highest values reported for marine mammals in recent years. Concentrations of organochlorines were highly correlated with one another. Concentrations of PCBs and DDTs in the blubber of gray whale, humpback whale, northern elephant seal, and harbor seal, and in the adipose fat of sea otter, were lower than the levels found in California sea lions, and were in the range of a few to several μg/g on a lipid weight basis

  4. Continuous catalytic hydrodechlorination of polychlorinated biphenyls (PCBs) in transformer oil.

    Science.gov (United States)

    Veriansyah, Bambang; Choi, Hye-Min; Lee, Youn-Woo; Kang, Jeong Won; Kim, Jae-Duck; Kim, Jaehoon

    2009-12-01

    Continuous catalytic hydrodechlorination of polychlorinated biphenyls (PCBs) in the presence of transformer oils was carried out in a fixed bed reactor using a 57.6 wt% Ni on silicon oxide-aluminum oxide (SiO(2)-Al(2)O(3)) catalyst. Reaction temperatures ranging 150-300 degrees C, PCBs concentrations ranging 50-200 ppm, and reaction times ranging 1-8 h were tested. At a higher reaction temperature or at a lower PCBs concentration, catalytic activity was higher and complete dechlorination of PCBs resulted even at long reaction time. Catalyst regeneration using hexane and 0.1 M sodium hydroxide (NaOH) was effective to restore the catalytic activity. Fresh, spent and regenerated catalysts were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. XRD analysis revealed growth of Ni crystallite size of the spent and the regenerated catalysts. XPS analysis showed that a considerable amount of chlorine and carbon species were deposited on the surface of the spent catalyst, which may play a role in the catalysts deactivation. PMID:20183511

  5. Toxicity mechanisms and interactions of polychlorinated biphenyls and polybrominated diphenylethers

    Directory of Open Access Journals (Sweden)

    Antonijević Biljana

    2012-01-01

    Full Text Available Polychlorinated biphenyls (PCBs and brominated flame retardants, polybrominated diphenylethers (PBDEs, are widespread environmental contaminants as a result of anthropogenic activities and due to their persistency and resistance to degradation. Both groups of chemicals are placed on the list of persistent organic pollutants (POPs, covered by the Stockholm convention which is aimed to limit or ban the production, use, emission, import and export of POPs in order to protect human health and the environment. Taking into account the structural similarity between PCBs and PBDEs, and the known effects of PCBs, these two groups of chemicals could have similar mechanisms of action. Also, because of real simultaneous exposure to these compounds, an examination of possible interactions is of great importance. Interactions of the compounds from these groups are likely at the system level of hormones, particularly thyroid and reproductive ones. As there are mechanisms of adverse effects of both groups of chemicals on the nervous system, including functional, neurological and behavioral changes, there are influences on neurotransmiters, changes in signal transduction and apoptosis. There are interactions affecting the occurrence of metabolic disorders as well. Data on the toxicity of mixtures of PCBs and PBDEs, as well as interactions of these chemicals would contribute to the processes of risk evaluation and risk characterisation. [Projekat Ministarstva nauke Republike Srbije, br. III 46009

  6. Reproduction success of American kestrels exposed to dietary polychlorinated biphenyls.

    Science.gov (United States)

    Fernie, K J; Smits, J E; Bortolotti, G R; Bird, D M

    2001-04-01

    While reproduction of wild birds is adversely affected by multiple environmental contaminants, we determined that polychlorinated biphenyls (PCBs) alone alter reproduction. Captive American kestrels (Falco sparverius), fed PCB-spiked (Aroclor 1248:1254:1260) food (7 mg/kg body weight/d) prior to and during the first breeding season only (100 d) laid eggs with environmentally relevant levels of total PCBs (34.0 microg/g whole egg wet wt vs 0 microg/g for controls). Reproduction changed during, not after, PCB exposure in this two-year study. The PCB-exposed pairs laid smaller clutches later in the season and laid more totally infertile clutches. Hatching success was reduced in PCB-exposed pairs, and 50% of PCB nestlings died within 3 d of hatching. Nearly 60% of PCB-exposed pairs with hatchlings failed to produce fledglings. Higher levels of total PCB residues and congeners were associated with later clutch initiation and fewer fertile eggs, hatchlings, and fledglings. We suggest that nonpersistent PCB congeners have a greater influence on reproduction than do persistent congeners. PMID:11345453

  7. Organochlorine pesticides and polychlorinated biphenyls in California sea lions

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, K.; Kajiwara, N.; Le Boeuf, B.J.; Tanabe, S

    2004-10-01

    Concentrations of polychlorinated biphenyls (PCBs), DDTs, chlordanes, HCHs, hexachlorobenzene (HCB), dieldrin, heptachlor epoxide, tris(4-chlorophenyl)methane (TCPMe), and tris(4-chlorophenyl)methanol (TCPMOH) were measured in the blubber of California sea lions (Zalophus californianus) collected in 2000. DDTs were the most predominant contaminants, followed by PCBs, chlordanes, TCPMe, HCHs, TCPMOH, dieldrin, and heptachlor epoxide. Concentrations of PCBs and DDTs varied from a few {mu}g/g to several hundreds of {mu}g/g on a lipid weight basis. Concentrations of DDTs have declined by an order of magnitude over the last three decades in California sea lions; nevertheless, the measured concentrations of PCBs and DDTs in California sea lions are still some of the highest values reported for marine mammals in recent years. Concentrations of organochlorines were highly correlated with one another. Concentrations of PCBs and DDTs in the blubber of gray whale, humpback whale, northern elephant seal, and harbor seal, and in the adipose fat of sea otter, were lower than the levels found in California sea lions, and were in the range of a few to several {mu}g/g on a lipid weight basis.

  8. Thermo-chemical destruction of polychlorinated biphenyls (PCBs) in waste insulating oil

    International Nuclear Information System (INIS)

    The feasibility of thermo-chemical destruction of polychlorinated biphenyls (PCBs) was investigated using a batch reactor and two different (vertical and horizontal) types of continuous reactor. A simple batch reactor was first designed and constructed to examine applicability of thermal-chemical destruction of PCBs. It was evidenced from the batch test results that the destruction of PCBs in the insulating oil (40% PCBs, w/w) was accomplished via abiotic dechlorination and mineralization of PCBs with quicklime at 600 deg C under nitrogen environment. PCB destruction efficiencies were obtained about 99.95%. The reaction was exothermic resulting release of heat by which the reactor temperature suddenly increased up to 750 deg C at the incipient 30 min of the experiment. Two major end products, CaCl2 and carbon, were identified. For a practical purpose, two continuous reactors were developed and tested. The observed continuous test results indicate that over 99.99% of PCB destruction efficiencies were achieved when excess quicklime (>3Ca:1Cl2 as a molar basis) was used. Specifically, the horizontal continuous reactor was suitable in view of ease of solid transfer, which is essential for complete destruction of PCBs and for full-scale applications

  9. Polychlorinated Biphenyls Induce Mitochondrial Dysfunction in SH-SY5Y Neuroblastoma Cells.

    Directory of Open Access Journals (Sweden)

    Stefania Cocco

    Full Text Available Chronic exposure to polychlorinated biphenyls (PCBs, ubiquitous environmental contaminants, can adversely affect the development and function of the nervous system. Here we evaluated the effect of PCB exposure on mitochondrial function using the PCB mixture Aroclor-1254 (A1254 in SH-SY5Y neuroblastoma cells. A 6-hour exposure to A1254 (5 μg/ml reduced cellular ATP production by 45%±7, and mitochondrial membrane potential, detected by TMRE, by 49%±7. Consistently, A1254 significantly decreased oxidative phosphorylation and aerobic glycolysis measured by extracellular flux analyzer. Furthermore, the activity of mitochondrial protein complexes I, II, and IV, but not V (ATPase, measured by BN-PAGE technique, was significantly reduced after 6-hour exposure to A1254. The addition of pyruvic acid during exposure to A1254 significantly prevent A1254-induced cell injury, restoring resting mitochondrial membrane potential, ATP levels, oxidative phosphorylation and aerobic glycolysis. Furthermore, pyruvic acid significantly preserved the activity of mitochondrial complexes I, II and IV and increased basal activity of complex V. Collectively, the present results indicate that the neurotoxicity of A1254 depends on the impairment of oxidative phosphorylation, aerobic glycolysis, and mitochondrial complexes I, II, and IV activity and it was counteracted by pyruvic acid.

  10. 1H NMR metabolomics of earthworm responses to polychlorinated biphenyl (PCB) exposure in soil.

    Science.gov (United States)

    Whitfield Åslund, Melissa L; Simpson, André J; Simpson, Myrna J

    2011-06-01

    (1)H NMR-based metabolomics was used to examine the metabolic profile of D(2)O-buffer extracted tissues of Eisenia fetida earthworms exposed for 2 days to an artificial soil spiked with sub-lethal concentrations of polychlorinated biphenyls (PCBs) (0, 0.5, 1, 5, 10, or 25 mg/kg Aroclor 1254). Univariate statistical analysis of the identified metabolites revealed a significant increase in ATP concentration in earthworms exposed to the highest soil PCB concentration, but detected no significant changes in other metabolites. However, a multivariate approach which considers alterations in multiple metabolites simultaneously, identified a significant linear relationship between earthworm metabolic profiles and PCB concentration (cross-validated PLS-regression with 7 components, R(2)X = 0.99, R(2)Y = 0.77, Q(2)Y = 0.45, P earthworms (r = 0.22, P = 0.54), but were positively correlated in earthworms from the 25 mg/kg treatment (r = 0.87, P = 0.001). Overall, the observed metabolic responses suggest that PCBs disrupted both carbohydrate (energy) metabolism and membrane (osmolytic) function in E. fetida. The ability of (1)H NMR-based metabolomics to detect these responses suggests that this method offers significant potential for direct assessment of sub-lethal PCB toxicity in soil. PMID:21424327

  11. A review of the neurotoxicity of non-dioxin-like polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Seegal, R. [Albany Univ., NY (United States). Wadsworth Center, New York State Dept. of Health and School of Public Health

    2004-09-15

    It is perhaps both presumptuous and somewhat nostalgic for me to present research findings from both myself and others describing the changes in central nervous system (CNS) function that occur following exposure to non-dioxin-like polychlorinated biphenyls (PCBs) at the 2004 Dioxin meeting. Presumptuous because my presentation occurs during this meeting where the majority of the research is concerned with the consequences of exposure to dioxins (the most toxic substance produced by man) and nostalgic because, in 1992, I presented some of my earliest work demonstrating that non-dioxin-like PCBs were capable of significantly altering neurochemical function. Much has changed in the intervening twelve years. Laboratories in the United States and Europe now routinely study and describe the neurotoxicological effects of developmental and in vitro exposure to non-dioxin-like PCBs. My task will be to briefly describe the highlights of that research and suggest additional approaches that will hopefully increase our ability to understand the mechanisms of action of non-dioxin-like PCBs on neuronal and behavioral function in populations of exposed humans.

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

    DEFF Research Database (Denmark)

    Petersen, Maria Skaalum; Halling, Jónrit; Damkier, Per;

    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 CYP3......A4 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 6beta-hydroxycortisol/cortisol (6beta...

  13. Photo-activated fluorescence detection of polychlorinated biphenyls in environmental matrices

    Energy Technology Data Exchange (ETDEWEB)

    Kozin, I.S.; Kwan, W.C.; Tabash, S.P; Brown, R.S. (Queen' s Univ., Kingston, ON (Canada) Dept. of Chemistry and School of Environmental Studies)

    1999-01-01

    It is often possible to employ fluorescence detection directly with minimal sample treatment or clean-up with species that are inherently luminescent. It is desirable to have a rapid detection scheme for polychlorinated biphenyls, but these methods are not used because PCBs are weakly or non-fluorescent. A scheme for the photo-activation of fluorescence for the detection of PCBs is described. Experiments with standard PCB mixtures (Aroclor 1254 and 1260) showed that using UV-initiated photolysis can of PCBs in different solvent systems can dramatically increase the fluorescence intensity. Linear calibration curves for the Aroclor mixtures were observed from 10ppb to 10ppm, giving the possibility of PCB detection in crude sediments extracts below the parts-per-million level. Further work is in progress to determine the influence of PCB congener, extraction solvent and method, and photolysis kinetics and possible interferences. That this method can successfuly be applied to contaminated sediments is suggested by initial experiments with real-world samples. Abstract no. 860.

  14. Photo-activated fluorescence detection of polychlorinated biphenyls in environmental matrices

    Energy Technology Data Exchange (ETDEWEB)

    Kozin, I.S.; Kwan, W.C.; Tabash, S.P; Brown, R.S. [Queen`s Univ., Kingston, ON (Canada) Dept. of Chemistry and School of Environmental Studies

    1999-11-01

    It is often possible to employ fluorescence detection directly with minimal sample treatment or clean-up with species that are inherently luminescent. It is desirable to have a rapid detection scheme for polychlorinated biphenyls, but these methods are not used because PCBs are weakly or non-fluorescent. A scheme for the photo-activation of fluorescence for the detection of PCBs is described. Experiments with standard PCB mixtures (Aroclor 1254 and 1260) showed that using UV-initiated photolysis can of PCBs in different solvent systems can dramatically increase the fluorescence intensity. Linear calibration curves for the Aroclor mixtures were observed from 10ppb to 10ppm, giving the possibility of PCB detection in crude sediments extracts below the parts-per-million level. Further work is in progress to determine the influence of PCB congener, extraction solvent and method, and photolysis kinetics and possible interferences. That this method can successfuly be applied to contaminated sediments is suggested by initial experiments with real-world samples. Abstract no. 860.

  15. Polychlorinated biphenyl contamination of the spider crab (Maja brachydactyla): influence of physiological and ecological processes.

    Science.gov (United States)

    Bodin, Nathalie; Caisey, Xavier; Abarnou, Alain; Loizeau, Véronique; Latrouite, Daniel; Le Guellec, Anne-Marie; Guillou, Monique

    2007-03-01

    Maja brachydactyla is a decapod crustacean widely distributed along the Northeast Atlantic coasts. The main objective of this work was to establish the influence of ontogenic factors, such as growth, aging, seasonal migrations, and reproduction, on the contamination of this species by polychlorinated biphenyls (PCBs). Two populations were studied: One in the Seine Bay (Eastern English Channel), which is exposed to greatly contaminated discharges from the Seine River, and one in the Iroise Sea (Western Brittany), which is little contaminated by such man-made compounds. At both sampling areas, PCB analysis revealed concentrations in hepatopancreas that were 10- and 50-fold higher than concentrations in gonads and muscle, respectively. Levels of 2,2',4,4',5,5'-hexachlorobiphenyl (CB153) increased with the age of the spider crabs, whereas their seasonal migrations had no direct effect. No significant sex effect was observed with regards to CB153 levels, but adult females exhibited PCB fingerprints different from those of males, probably because of the influence of the reproductive cycle on enzymatic system activity. Finally, spawning gave rise to a higher CB153 decontamination of female body burdens for specimens from the Iroise Sea than for those from the Seine Bay. PMID:17373508

  16. Insight into the neuroproteomics effects of the food-contaminant non-dioxin like polychlorinated biphenyls.

    Science.gov (United States)

    Brunelli, Laura; Llansola, Marta; Felipo, Vicente; Campagna, Roberta; Airoldi, Luisa; De Paola, Massimiliano; Fanelli, Roberto; Mariani, Alessandro; Mazzoletti, Marco; Pastorelli, Roberta

    2012-04-18

    Recent studies showed that food-contaminant non-dioxin-like polychlorinated biphenyls (NDL-PCBs) congeners (PCB52, PCB138, PCB180) have neurotoxic potential, but the cellular and molecular mechanisms underlying neuronal damage are not entirely known. The aim of this study was to assess whether in-vitro exposure to NDL-PCBs may alter the proteome profile of primary cerebellar neurons in order to expand our knowledge on NDL-PCBs neurotoxicity. Comparison of proteome from unexposed and exposed rat cerebellar neurons was performed using state-of-the-art label-free semi-quantitative mass-spectrometry method. We observed significant changes in the abundance of several proteins, that fall into two main classes: (i) novel targets for both PCB138 and 180, mediating the dysregulation of CREB pathways and ubiquitin-proteasome system; (ii) different congeners-specific targets (alpha-actinin-1 for PCB138; microtubule-associated-protein-2 for PCB180) that might lead to similar deleterious consequences on neurons cytoskeleton organization. Interference of the PCB congeners with synaptic formation was supported by the increased expression of pre- and post-synaptic proteins quantified by western blot and immunocytochemistry. Expression alteration of synaptic markers was confirmed in the cerebellum of rats developmentally exposed to these congeners, suggesting an adaptive response to neurodevelopmental toxicity on brain structures. As such, our work is expected to lead to new insights into the mechanisms of NDL-PCBs neurotoxicity. PMID:22387315

  17. Toxicological effects of polychlorinated biphenyls (PCBs) on freshwater turtles in the United States.

    Science.gov (United States)

    Ming-Ch'eng Adams, Clare Isabel; Baker, Joel E; Kjellerup, Birthe V

    2016-07-01

    Prediction of vertebrate health effects originating from persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) has remained a challenge for decades thus making the identification of bioindicators difficult. POPs are predominantly present in soil and sediment, where they adhere to particles due to their hydrophobic characteristics. Animals inhabiting soil and sediment can be exposed to PCBs via dermal exposure while others may obtain PCBs through contaminated trophic interaction. Freshwater turtles can serve as bioindicators due to their strong site fidelity, longevity and varied diet. Previous research observed the health effects of PCBs on turtles such as decreased bone mass, changed sexual development and decreased immune responses through studying both contaminated sites along with laboratory experimentation. Higher deformity rates in juveniles, increased mortality and slower growth have also been observed. Toxicological effects of PCBs vary between species of freshwater turtles and depend on the concertation and configuration of PCB congeners. Evaluation of ecotoxicological effects of PCBs in non-endangered turtles could provide important knowledge about the health effects of endangered turtle species thus inform the design of remediation strategies. In this review, the PCB presence in freshwater turtle habitats and the ecotoxicological effects were investigated with the aim of utilizing the health status to identify areas of focus for freshwater turtle conservation. PMID:27043381

  18. Reactivation of an Idle Lease to Increase Heavy Oil Recovery through Application of Conventional Steam Drive Technology in a Low Dip Slope and Reservoir in the Midway-Sunset Field, San Jaoquin Basin, California

    Energy Technology Data Exchange (ETDEWEB)

    Schamel, Steven

    1999-07-08

    This project reactivates ARCO's idle Pru Fee lease in the Midway-Sunset field, California and conducts a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. Cyclic steam was used to reestablish baseline production within the reservoir characterization phase of the project completed in December 1996. During the demonstration phase begun in January 1997, a continuous steamflood enhanced oil recovery is testing the incremental value of this method as an alternative to cyclic steaming. Other economically marginal Class III reservoirs having similar producibility problems will benefit from insight gained in this project. The objective of the project are: (1) to return the shut-in portion of the reservoir to optimal commercial production; (2) to accurately describe the reservoir and recovery process; and (3) to convey the details of this activity to the domestic petroleum industry, especially to other producers in California, through an aggressive technology transfer program.

  19. Reactivation of an Idle Lease to Increase Heavy Oil Recovery Through Application of Conventional Steam Drive Technology in a Low Dip Slope and Basin Resrvoir in the Midway-Sunset Field, San Jaoquin Basin, California

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Creties; Sprinkel, Doug; Deo, Milind; Wydrinski, Ray; Swain, Robert

    1997-10-21

    This project reactivates ARCO's idle Pru Fee lease in the Midway-Sunset field, California and conducts a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. Cyclic steaming is being used to reestablish baseline production within the reservoir characterization phase of the project. During the demonstration phase scheduled to begin in January 1997, a continuous steamflood enhanced oil recovery will be initiated to test the incremental value of this method as an alternative to cyclic steaming. Other economically marginal Class III reservoirs having similar producibility problems will benefit from insight gained in this project. The objectives of the project are: (1) to return the shut-in portion of the reservoir to optimal commercial production; (2) to accurately describe the reservoir and recovery process; and (3) to convey the details of this activity to the domestic petroleum industry, especially to other producers in California, through an aggressive technology transfer program.

  20. Reactivation of an Idle Lease to Increase Heavy Oil Recovery through Application of Conventional Steam Drive Technology in a Low Dip Slope and Basin Reservoir in the Midway-Sunset Field, San Jaoquin Basin, California

    Energy Technology Data Exchange (ETDEWEB)

    Deo, M.; Forster, C.; Jenkins, C.; Schamel, S.; Sprinkel, D.; and Swain, R.

    1999-02-01

    This project reactivates ARCO's idle Pru Fee lease in the Midway-Sunset field, California and conducts a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. Cyclic steaming was used to reestablish baseline production within the reservoir characterization phase of the project completed in December 1996. During the demonstration phase begun in January 1997, a continuous steamflood enhanced oil recovery is testing the incremental value of this method as an alternative to cyclic steaming. Other economically marginal Class III reservoirs having simular producibility problems will benefit from insight gained in this project. The objectives of the project are: (1) to return the shut-in portion of the reservoir to optimal commercial production; (2) to accurately describe the reservoir and recovery process; and (3) to convey the details of this activity to the domestic petroleum industry, especially t o other producers in California, through an aggressive technology transfer program.

  1. Increased reactive oxygen species production and lower abundance of complex I subunits and carnitine palmitoyltransferase 1B protein despite normal mitochondrial respiration in insulin-resistant human skeletal muscle

    DEFF Research Database (Denmark)

    Lefort, Natalie; Glancy, Brian; Bowen, Benjamin;

    2010-01-01

    abundance present in insulin-resistant muscle. RESEARCH DESIGN AND METHODS: Mitochondria were isolated from vastus lateralis muscle from lean and insulin-sensitive individuals and from obese and insulin-resistant individuals who were otherwise healthy. Respiration and reactive oxygen species (ROS......) production rates were measured in vitro. Relative abundances of proteins detected by mass spectrometry were determined using a normalized spectral abundance factor method. RESULTS: NADH- and FADH(2)-linked maximal respiration rates were similar between lean and obese individuals. Rates of pyruvate...... the higher ROS production. Tandem mass spectrometry identified protein abundance differences per mitochondrial mass in insulin resistance, including lower abundance of complex I subunits and enzymes involved in the oxidation of branched-chain amino acids (BCAA) and fatty acids (e.g., carnitine...

  2. Dietary uptake of polychlorinated biphenyls (PCBs) by rainbow trout

    Science.gov (United States)

    Carline, Robert F.; Barry, Patrick M.; Ketola, H. George

    2004-01-01

    The presence of detectable levels of polychlorinated biphenyls (PCBs) in commercially produced fish feed has raised a concern about the degree of biomagnification of these contaminants in hatchery-reared trout. Our objectives were to (1) define the relationship between concentrations of PCBs in fish feed and in fish tissue and (2) estimate the relative contributions of feed and hatchery supply water to PCB concentrations in fish. We conducted a 6-month feeding trial with fingerling rainbow trout Oncorhynchus mykiss fed commercial diets with four concentrations of PCBs: a low-PCB diet (69 ng/g); a typical commercial diet (126 ng/g); and the typical diet spiked with PCBs at two levels (220 and 280 ng/g). The concentrations of PCBs in fillets after 1 month were commensurate with those in the feeds and remained relatively stable for the next 5 months; mean PCB concentrations in fillets ranged from 54 to 94 ng/g. Low levels of PCBs were detected in the hatchery supply water. We used the concentrations of PCBs in the feeds, absorption rates of PCBs, and two different rates of PCB depuration to estimate the potential uptake of PCBs from supply water. When we used a low depuration rate (half-life = 219 d), the computed body burdens of PCBs could be entirely attributed to the feeds. When a high depuration rate (half-life = 66 d) was used, some uptake of PCBs from the supply water was likely, but most of the total body burden originated from the feeds. We concluded that rainbow trout fed a diet with 126 ng/g PCBs would have a PCB concentration of about 60 ng/g in their fillets, which is high enough to warrant issuance of a consumption advisory (no more than one meal of fish per week) under a protocol adopted by some Great Lakes states.

  3. Human receptor activation by aroclor 1260, a polychlorinated biphenyl mixture.

    Science.gov (United States)

    Wahlang, Banrida; Falkner, K Cameron; Clair, Heather B; Al-Eryani, Laila; Prough, Russell A; States, J Christopher; Coslo, Denise M; Omiecinski, Curtis J; Cave, Matthew C

    2014-08-01

    Polychlorinated biphenyls (PCBs) are persistent environmental toxicants, present in 100% of U.S. adults and dose-dependently associated with obesity and non-alcoholic fatty liver disease (NAFLD). PCBs are predicted to interact with receptors previously implicated in xenobiotic/energy metabolism and NAFLD. These receptors include the aryl hydrocarbon receptor (AhR), pregnane xenobiotic receptor (PXR), constitutive androstane receptor (CAR), peroxisome proliferator-activated receptors (PPARs), liver-X-receptor (LXRα), and farnesoid-X-receptor (FXR). This study evaluates Aroclor 1260, a PCB mixture with congener composition mimicking that of human adipose tissue, and selected congeners, as potential ligands for these receptors utilizing human hepatoma-derived (HepG2) and primate-derived (COS-1) cell lines, and primary human hepatocytes. Aroclor 1260 (20 μg/ml) activated AhR, and PCB 126, a minor component, was a potent inducer. Aroclor 1260 activated PXR in a simple concentration-dependent manner at concentrations ≥10 μg/ml. Among the congeners tested, PCBs 138, 149, 151, 174, 183, 187, and 196 activated PXR. Aroclor 1260 activated CAR2 and CAR3 variants at lower concentrations and antagonize CAR2 activation by the CAR agonist, CITCO, at higher concentrations (≥20 μg/ml). Additionally, Aroclor 1260 induced CYP2B6 in primary hepatocytes. At subtoxic doses, Aroclor 1260 did not activate LXR or FXR and had no effect on LXR- or FXR-dependent induction by the agonists T0901317 or GW4064, respectively. Aroclor 1260 (20 μg/ml) suppressed PPARα activation by the agonist nafenopin, although none of the congeners tested demonstrated significant inhibition. The results suggest that Aroclor 1260 is a human AhR, PXR and CAR3 agonist, a mixed agonist/antagonist for CAR2, and an antagonist for human PPARα. PMID:24812009

  4. Immunotoxicity Monitoring in a Population Exposed to Polychlorinated Biphenyls.

    Science.gov (United States)

    Haase, Hajo; Fahlenkamp, Astrid; Schettgen, Thomas; Esser, Andre; Gube, Monika; Ziegler, Patrick; Kraus, Thomas; Rink, Lothar

    2016-01-01

    The relationship between polychlorinated biphenyl (PCB) burden and several indicators of immune function was investigated as part of the HELPcB (Health Effects in High-Level Exposure to PCB) program, offering bio-monitoring to workers, relatives, and neighbors exposed to PCBs by a German transformers and capacitors recycling company. The present retrospective observational study evaluates the correlation of plasma levels of total PCBs, five indicator congeners (28, 101, 138, 153, 180), and seven dioxin-like congeners (105, 114, 118, 156, 157, 167, 189) with several parameters of immune function. The cross-sectional study was performed immediately after the end of exposure (258 subjects), and one (218 subjects), and two (177 subjects) years later. At the first time point, measurements showed significant positive correlation between congeners with low to medium chlorination and the relative proportion of CD19 positive B-cells among lymphocytes, as well as a negative correlation of PCB114 with serum IgM, and of PCB 28 with suppressor T-cell and NK-cell numbers. Congeners with a high degree of chlorination, in particular PCB157 and 189, were positively associated with expression of the activation marker CD25 on T-cells in the cohort of the second time point. No associations between PCB levels and IFN-y production by T-cells and killing by NK-cells were found. In conclusion, there were several effects on the cellular composition of adaptive immunity, affecting both T- and B-cells. However, the values were not generally outside the reference ranges for healthy adult individuals and did not indicate overt functional immunodeficiency, even in subjects with the uppermost PCB burden. PMID:27005643

  5. Immunotoxicity Monitoring in a Population Exposed to Polychlorinated Biphenyls

    Directory of Open Access Journals (Sweden)

    Hajo Haase

    2016-03-01

    Full Text Available The relationship between polychlorinated biphenyl (PCB burden and several indicators of immune function was investigated as part of the HELPcB (Health Effects in High-Level Exposure to PCB program, offering bio-monitoring to workers, relatives, and neighbors exposed to PCBs by a German transformers and capacitors recycling company. The present retrospective observational study evaluates the correlation of plasma levels of total PCBs, five indicator congeners (28, 101, 138, 153, 180, and seven dioxin-like congeners (105, 114, 118, 156, 157, 167, 189 with several parameters of immune function. The cross-sectional study was performed immediately after the end of exposure (258 subjects, and one (218 subjects, and two (177 subjects years later. At the first time point, measurements showed significant positive correlation between congeners with low to medium chlorination and the relative proportion of CD19 positive B-cells among lymphocytes, as well as a negative correlation of PCB114 with serum IgM, and of PCB 28 with suppressor T-cell and NK-cell numbers. Congeners with a high degree of chlorination, in particular PCB157 and 189, were positively associated with expression of the activation marker CD25 on T-cells in the cohort of the second time point. No associations between PCB levels and IFN-y production by T-cells and killing by NK-cells were found. In conclusion, there were several effects on the cellular composition of adaptive immunity, affecting both T- and B-cells. However, the values were not generally outside the reference ranges for healthy adult individuals and did not indicate overt functional immunodeficiency, even in subjects with the uppermost PCB burden.

  6. Formation and stability of polychlorinated biphenyl Pickering emulsions

    Science.gov (United States)

    Roy-Perreault, Andréanne; Kueper, Bernard H.; Rawson, Jim

    2005-03-01

    An emulsion stabilized by colloidal suspensions of finely divided solids is known as a Pickering emulsion. The potential for polychlorinated biphenyls (PCBs) to form Pickering emulsions ex situ when in contact with powdered solids, such as clays and metal oxides, is investigated here. Bentonite, iron oxide and magnesium oxide dispersions proved to be robust Pickering emulsion stabilizers, whereas manganese oxide dispersions were not. Batch experiments revealed that emulsions can be formed using a moderately low energy input and can be stabilized with solid concentrations as low as 0.5 wt.%. For the base conditions (volumetric oil fraction ( ϕoil)=30 vol.%; solid concentration ( χ)=2 wt.%), the formed emulsions were indefinitely stable and the initial average droplet diameters varied from 80 to 258 μm, depending on the solid used in the colloidal dispersion. The average droplet size varied at early time, but for most conditions stabilized to a steady-state value 1 week after preparation. The effect of Ostwald ripening was limited. At greater than 0.5 wt.% concentration, the efficiency of the solid dispersion as a stabilizer was dependant on the volumetric oil fraction but not on the solid concentration. Generally, systems with volumetric oil fractions outside of the 20-70 vol.% range were unstable. The emulsions' droplet stability, average droplet size and size distribution were observed to vary as a function of the amount of energy provided to the system, the volumetric oil fraction, and the concentration of the solid in the aqueous dispersion. It is hypothesized that drilling through fractured rock in the immediate vicinity of dense, non-aqueous phase liquid (DNAPL) PCBs may provide both the energy and solid material necessary to form Pickering emulsions.

  7. Spermaturia and serum hormone concentrations at the age of puberty in boys prenatally exposed to polychlorinated biphenyls

    DEFF Research Database (Denmark)

    Mol, Nanette M; Sørensen, Nicolina; Weihe, Pal;

    2002-01-01

    To determine whether prenatal exposure to polychlorinated biphenyls (PCBs) with possible hormone-disrupting effects is capable of affecting sexual differentiation in boys at the age of puberty.......To determine whether prenatal exposure to polychlorinated biphenyls (PCBs) with possible hormone-disrupting effects is capable of affecting sexual differentiation in boys at the age of puberty....

  8. Charging reactive power considering system security aspects

    International Nuclear Information System (INIS)

    The pricing of reactive power in power systems was discussed. This issue does not draw much attention because reactive power typically responds to only a small share of the total market power. The challenge in system security arises when the reactive power market is considered as an auxiliary tool to improve the voltage level profile and the reactive power control is considered to obtain a larger load margin. In such cases, for each transaction, the responsibility of the reactive power changes are determined along with some control actions to reduce the system loss in the critical area, and to increase the load margin. This paper also presented a new approach for pricing these control actions and outlined some system configurations and operating conditions. Tests were performed using a real 39-bus system sample in which all limits were considered.

  9. Molecular Descriptors Family on Structure Activity Relationships 6. Octanol-Water Partition Coefficient of Polychlorinated Biphenyls

    Directory of Open Access Journals (Sweden)

    Lorentz JÄNTSCHI

    2006-01-01

    Full Text Available Octanol-water partition coefficient of two hundred and six polychlorinated biphenyls was model by the use of an original method based on complex information obtained from compounds structure. The regression analysis shows that best results are obtained in four-varied model (r2 = 0.9168. The prediction ability of the model was studied through leave-one-out analysis (r2cv(loo = 0.9093 and in training and test sets analysis. Modeling the octanol-water partition coefficient of polychlorinated biphenyls by integration of complex structural information provide a stable and performing four-varied model, allowing us to make remarks about relationship between structure of polychlorinated biphenyls and associated octanol-water partition coefficients.

  10. 2,2,6,6-Tetrakis(biphenyl-2-yl-4,4,8,8-tetramethylcyclotetrasiloxane

    Directory of Open Access Journals (Sweden)

    Erik P. A. Couzijn

    2009-09-01

    Full Text Available The title compound, [–Si(C12H92OSi(CH32O–]2, was obtained unintentionally as the product of an attempted crystallization of caesium bis(biphenyl-2,2′-diylfluorosilicate from dimethylformamide. In the crystal, the molecule is located on an inversion center and the siloxane ring adopts a twist-chair conformation with the two dimethyl-substituted Si atoms lying 0.7081 (5 Å out of the plane defined by the two bis(biphenyl-2-yl-substituted Si atoms and the four O atoms. In each Si(C12H92 unit, the orientation of one terminal phenyl ring relative to the phenylene ring of the other biphenyl moiety suggests a parallel displaced π–π stacking interaction [centroid distance = 4.2377 (11 Å and dihedral angle = 15.40 (9°].

  11. Effect of additives on the performance and morphology of sulfonated copoly (phthalazinone biphenyl ether sulfone) composite nanofiltration membranes☆

    Science.gov (United States)

    Guan, Shanshan; Zhang, Shouhai; Liu, Peng; Zhang, Guozhen; Jian, Xigao

    2014-03-01

    Sulfonated copoly (phthalazinone biphenyl ether sulfone) (SPPBES) composite nanofiltration membranes were fabricated by adding low molecular weight additives into SPPBES coating solutions during a dip coating process. Three selected additives: glycol, glycerol and hydroquinone were used in this work. The effect of additives on the membrane performance was studied and discussed in terms of rejection and permeation flux. Among all the composite membranes, the membrane prepared with glycol as an additive achieved the highest Na2SO4 rejection, and the membrane fabricated with glycerol as an additive exhibited the highest flux. The salts rejection of SPPBES composite membranes increased in the following order MgCl2 < NaCl ≤ MgSO4 < Na2SO4. The morphologies of the SPPBES composite membranes were characterized by SEM, it was found that the membrane prepared with hydroquinone showed a rough membrane surface. Composite membrane fabricated with glycol or glycerol as the additive showed very good chemical stability.

  12. Flows of Reactive Fluids

    CERN Document Server

    Prud'homme, Roger

    2010-01-01

    The modeling of reactive flows has progressed mainly with advances in aerospace, which gave birth to a new science called aerothermochemistry, as well as through developments in chemical and process engineering. The methods employed, the phenomena investigated, and the aims of modeling differ for each field; however, in all cases, the results obtained have considerably enriched the working knowledge of reactive flows. This work examines basic concepts and methods necessary to study reactive flows and transfer phenomena in areas such as fluid mechanics, thermodynamics, and chemistry. Specific topics covered include: * Equations of state * Transfer phenomena and chemical kinetics * Balance equations of reactive flows * Dimensionless numbers and similarity * Chemical reactors * Coupled phenomena * Turbulent flow concepts * Boundary layers and fluid layers * Reactive and nonreactive waves * Interface phenomena * Multiphase flow concepts The book presents tools of interest to graduate students, researchers in math...

  13. Occurrence and exposure assessment of polychlorinated biphenyls and organochlorine pesticides from homemade baby food in Korea.

    Science.gov (United States)

    Jeong, Yunsun; Lee, Sunggyu; Kim, Sunmi; Choi, Sung-Deuk; Park, Jeongim; Kim, Hai-Joong; Lee, Jeong Jae; Choi, Gyuyeon; Choi, Sooran; Kim, Sungjoo; Kim, Su Young; Kim, Young Don; Cho, Geumjoon; Suh, Eunsook; Kim, Sung Koo; Eun, So-Hee; Eom, Soyong; Kim, Seunghyo; Kim, Gun-Ha; Choi, Kyungho; Kim, Sungkyoon; Moon, Hyo-Bang

    2014-02-01

    Data on the residue levels of persistent organic pollutants (POPs) in baby food samples are scarce. This is the first study to explore current contamination status and exposure assessment of organochlorines (OCs), including polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), in baby food from Korea. In this study, the concentrations of OCs were determined in homemade baby food samples (n=100) collected from 6-, 9-, 12- and 15-month-old infant groups. The average concentrations of PCBs, dichloro-diphenyl-trichloroethanes (DDTs), hexachlorocyclohexanes (HCHs) and chlordanes (CHLs) in baby food samples were 37.5, 96.6, 26.0, and 13.2 pg/g fresh weight, respectively. The major compounds were CBs 28, 153, 52, and 33 for PCBs and p,p'-DDE, p,p'-DDT and β-HCH for OCPs. The contribution of DDTs to the total OC concentrations increased from 30% (6-month-old infants) to 67% (15-month-old infants) with increasing infant age, while the concentrations of PCBs, HCHs and CHLs gradually decreased with increasing infant age, suggesting that highest priority for risk reduction of DDTs. The estimated daily intakes (EDIs) of OCs in Korean infants from baby food consumption were lower than the thresholds proposed by the United States Environmental Protection Agency and Health Canada, implying limited potential health risks. However, considering simultaneous exposure from baby food and breast milk consumption, chlordanes and heptachlor epoxide posed potential health risks. Considering the importance of early development and the vulnerability of infants, it is essential to perform systematic monitoring and management programs of OCs in baby food for risk reduction in Korean infants. PMID:23954213

  14. Metabolomic analysis of the effects of polychlorinated biphenyls in nonalcoholic fatty liver disease.

    Science.gov (United States)

    Shi, Xue; Wahlang, Banrida; Wei, Xiaoli; Yin, Xinmin; Falkner, K Cameron; Prough, Russell A; Kim, Seong Ho; Mueller, Eugene G; McClain, Craig J; Cave, Matthew; Zhang, Xiang

    2012-07-01

    Polychlorinated biphenyls (PCBs) are persistent organic pollutants and have been associated with abnormal liver enzymes and suspected nonalcoholic fatty liver disease (NAFLD), obesity, and the metabolic syndrome in epidemiological studies. In epidemiological surveys of human PCB exposure, PCB 153 has the highest serum levels among PCB congeners. To determine the hepatic effects of PCB 153 in mice, C57BL/6J mice were fed either a control diet (CD) or a high fat diet (HFD) for 12 weeks, with or without PCB 153 coexposure. The metabolite extracts from mouse livers were analyzed using linear trap quadrupole-Fourier transform ion cyclotron resonance mass spectrometer (LTQ-FTICR MS) via direct infusion nanoelectrospray ionization (DI-nESI) mass spectrometry. The metabolomics analysis indicated no difference in the metabolic profile between mice fed the control diet with PCB 153 exposure (CD+PCB 153) and mice fed the control diet (CD) without PCB 153 exposure. However, compared with CD group, levels of 10 metabolites were increased and 15 metabolites were reduced in mice fed HFD. Moreover, compared to CD+PCB 153 group, the abundances of 6 metabolites were increased and 18 metabolites were decreased in the mice fed high fat diet with PCB 153 exposure (HFD+PCB 153). Compared with HFD group, the abundances of 2 metabolites were increased and of 12 metabolites were reduced in HFD+PCB 153 group. These observations agree with the histological results and indicate that the metabolic effects of PCB 153 were highly dependent on macronutrient interactions with HFD. Antioxidant depletion is likely to be an important consequence of this interaction, as this metabolic disturbance has previously been implicated in obesity and NAFLD. PMID:22686559

  15. Long-time measurements of polychlorinated dibenzodioxins (PCDD), dibenzofurans (PCDF) and biphenyls (PCB) in deposition

    International Nuclear Information System (INIS)

    Dioxins, furans and polychlorinated biphenyls from one and the same sample were first separated by chromatography, then determined by mass spectroscopy. Sampling was in accordance with VDI method No. 2119, sheet 2, for the measurement of particulate precipitations. The annual means of PCDD/PCDF deposition ranged from 10 to 83 pg TE/(m2.d). The annual means of the deposition of polychlorinated biphenyls (tri and decachlorobiphenyls combined) varied between 23 and 257 ng/(m2.d). The annual mean for coplanar PCBs No. 77, 126 and 169 was less than 1 ng/(m2.d). (orig./DG)

  16. Reactivation of an idle lease to increase heavy oil recovery through application of conventional steam drive technology in a low dip slope and basin reservoir in the Midway-Sunset Field, San Jaoquin Basin, California

    Energy Technology Data Exchange (ETDEWEB)

    Schamel, S.

    1996-11-01

    This project reactivates ARCO`s idle Pru Fee lease in the Midway- Sunset field, California and conducts a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. Cyclic steaming is being used to reestablish baseline production within the reservoir characterization phase of the project. During the demonstration phase scheduled to begin in January 1997, a continuous steamflood enhanced oil recovery will be initiated to test the incremental value of this method as an alternative to cyclic steaming. Other economically marginal Class III reservoirs having similar producibility problems will benefit from insight gained in this project. The objectives of the project are: (1) to return the shut-in portion of the reservoir to optimal commercial production; (2) to accurately describe the reservoir and recovery process; and (3) to convey the details of this activity to the domestic petroleum industry, especially to other producers in California, through an aggressive technology transfer program. One of the main objectives of Budget Period I was to return the Pru Fee property to economic production and establish a baseline productivity with cyclic steaming. By the end of the second quarter 1996, all Pru producers except well 101 had been cyclic steamed two times. Each steam cycle was around 10,000 barrels of steam (BS) per well. No mechanical problems were found in the existing old wellbores. Conclusion is after several years of being shut-in, the existing producers on the Pru lease are in reasonable mechanical condition, and can therefore be utilized as viable producers in whatever development plan we determine is optimum. Production response to cyclic steam is very encouraging in the new producer, however productivity in the old producers appears to be limited in comparison.

  17. Increased Reactive Oxygen Species Production and Lower Abundance of Complex I Subunits and Carnitine Palmitoyltransferase 1B Protein Despite Normal Mitochondrial Respiration in Insulin-Resistant Human Skeletal Muscle

    Science.gov (United States)

    Lefort, Natalie; Glancy, Brian; Bowen, Benjamin; Willis, Wayne T.; Bailowitz, Zachary; De Filippis, Elena A.; Brophy, Colleen; Meyer, Christian; Højlund, Kurt; Yi, Zhengping; Mandarino, Lawrence J.

    2010-01-01

    OBJECTIVE The contribution of mitochondrial dysfunction to skeletal muscle insulin resistance remains elusive. Comparative proteomics are being applied to generate new hypotheses in human biology and were applied here to isolated mitochondria to identify novel changes in mitochondrial protein abundance present in insulin-resistant muscle. RESEARCH DESIGN AND METHODS Mitochondria were isolated from vastus lateralis muscle from lean and insulin-sensitive individuals and from obese and insulin-resistant individuals who were otherwise healthy. Respiration and reactive oxygen species (ROS) production rates were measured in vitro. Relative abundances of proteins detected by mass spectrometry were determined using a normalized spectral abundance factor method. RESULTS NADH- and FADH2-linked maximal respiration rates were similar between lean and obese individuals. Rates of pyruvate and palmitoyl-dl-carnitine (both including malate) ROS production were significantly higher in obesity. Mitochondria from obese individuals maintained higher (more negative) extramitochondrial ATP free energy at low metabolic flux, suggesting that stronger mitochondrial thermodynamic driving forces may underlie the higher ROS production. Tandem mass spectrometry identified protein abundance differences per mitochondrial mass in insulin resistance, including lower abundance of complex I subunits and enzymes involved in the oxidation of branched-chain amino acids (BCAA) and fatty acids (e.g., carnitine palmitoyltransferase 1B). CONCLUSIONS We provide data suggesting normal oxidative capacity of mitochondria in insulin-resistant skeletal muscle in parallel with high rates of ROS production. Furthermore, we show specific abundance differences in proteins involved in fat and BCAA oxidation that might contribute to the accumulation of lipid and BCAA frequently associated with the pathogenesis of insulin resistance. PMID:20682693

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

    International Nuclear Information System (INIS)

    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.

  19. Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species

    International Nuclear Information System (INIS)

    The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorly investigated in wild birds. This is the case for stress hormones including corticosterone (CORT). Some studies have suggested that environmental exposure to PCBs and altered CORT secretion might be associated. Here we investigated the relationships between blood PCB concentrations and circulating CORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hence covering a wide range of PCB exposure. Blood ∑7PCB concentrations (range: 61–115,632 ng/g lw) were positively associated to baseline or stress-induced CORT levels in three species and negatively associated to stress-induced CORT levels in one species. Global analysis suggests that in males, baseline CORT levels generally increase with increasing blood ∑7PCB concentrations, whereas stress-induced CORT levels decrease when reaching high blood ∑7PCB concentrations. This study suggests that the nature of the PCB-CORT relationships may depend on the level of PCB exposure. - Highlights: • Relationships between PCBs and stress hormones (CORT) are not well known in birds. • We measured blood PCBs, baseline and stress-induced CORT in seven seabird species. • ∑PCB was positively associated to baseline or stress-induced CORT in three species. • ∑PCBs was negatively linked to stress-induced CORT in the most contaminated species. • The nature of the PCB-CORT relationships may depend on the level of PCB exposure. - In polar seabird species, the relationship between PCB and CORT concentrations may be related to the levels of contamination

  20. Modeling Population-Level Consequences of Polychlorinated Biphenyl Exposure in East Greenland Polar Bears.

    Science.gov (United States)

    Pavlova, Viola; Grimm, Volker; Dietz, Rune; Sonne, Christian; Vorkamp, Katrin; Rigét, Frank F; Letcher, Robert J; Gustavson, Kim; Desforges, Jean-Pierre; Nabe-Nielsen, Jacob

    2016-01-01

    Polychlorinated biphenyls (PCBs) can cause endocrine disruption, cancer, immunosuppression, or reproductive failure in animals. We used an individual-based model to explore whether and how PCB-associated reproductive failure could affect the dynamics of a hypothetical polar bear (Ursus maritimus) population exposed to PCBs to the same degree as the East Greenland subpopulation. Dose-response data from experimental studies on a surrogate species, the mink (Mustela vision), were used in the absence of similar data for polar bears. Two alternative types of reproductive failure in relation to maternal sum-PCB concentrations were considered: increased abortion rate and increased cub mortality. We found that the quantitative impact of PCB-induced reproductive failure on population growth rate depended largely on the actual type of reproductive failure involved. Critical potencies of the dose-response relationship for decreasing the population growth rate were established for both modeled types of reproductive failure. Comparing the model predictions of the age-dependent trend of sum-PCBs concentrations in females with actual field measurements from East Greenland indicated that it was unlikely that PCB exposure caused a high incidence of abortions in the subpopulation. However, on the basis of this analysis, it could not be excluded that PCB exposure contributes to higher cub mortality. Our results highlight the necessity for further research on the possible influence of PCBs on polar bear reproduction regarding their physiological pathway. This includes determining the exact cause of reproductive failure, i.e., in utero exposure versus lactational exposure of offspring; the timing of offspring death; and establishing the most relevant reference metrics for the dose-response relationship. PMID:26289812

  1. Reproductive abnormalities, teratogenicity, and developmental problems in American kestrels (Falco sparverius) exposed to polychlorinated biphenyls.

    Science.gov (United States)

    Fernie, Kim; Bortolotti, Gary; Smits, Judit

    2003-11-28

    This study found abnormalities in multiple reproductive stages in captive American kestrels (Falco sparverius) when exposed to polychlorinated biphenyls (PCBs) through dietary and in ovo exposure. American kestrels laid eggs with environmentally relevant total PCB levels (34.1 micrograms/g whole egg wet weight) when consuming PCB-spiked (Aroclor 1248:1254:1260) food (5-7 micrograms/g body weight per day) for 100 d only in 1998. In 1999, the same adults laid eggs with estimated total PCBs of 23 micrograms/g. Effects of maternal (only female exposed) and paternal (only male exposed) in ovo PCB exposure were investigated. Maternal F1 eggs contained predicted total PCB concentrations of 0.34 microgram/g. Specific abnormalities occurred more frequently during dietary F0 exposure, particularly aggressive courtship interactions, clutch abandonment, occurrences of cracked eggs, and developmental effects. Multiple developmental effects were more pronounced during than after dietary PCB exposure of adults, and although these effects were limited, nevertheless they occurred in the F1 maternal and F1 paternal pairs. However, the incidence of multiple deformities throughout the breeding season increased dramatically from 1998 (13%) to 1999 (56%) in F0 PCB-exposed pairs. Developmental abnormalities were unlikely to be attributed to the extrinsic factors of disease, genetics, or nutritional (vitamin D3) deficiencies, but rather to adverse changes in parental behavior and intrinsic factors involving altered genetic material and PCB exposure. Readily cleared PCB congeners may induce specific types of behavioral and developmental abnormalities, but persistent congeners and metabolites are likely producing (1) odd laying patterns, (2) odd laying patterns, (2) developmental effects including embryonic underdevelopment and edema, and (3) increased incidences of multiple deformities within a clutch. PMID:14710594

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

    International Nuclear Information System (INIS)

    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 14C-labelled and in equimolar doses (2.0 μmol/kg body wt.)). CB-77 resulted in the comparatively strongest foetal 14C-accumulation, when measured in plasma or whole body homogenate four days after administration (day 17 of pregnancy); the plasma 14C-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 14C-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

  3. Lactational transfer of mercury and polychlorinated biphenyls in polar bears.

    Science.gov (United States)

    Knott, Katrina K; Boyd, Daryle; Ylitalo, Gina M; O'Hara, Todd M

    2012-07-01

    We examined concentrations of total mercury (tHg, inorganic and methylated forms) and polychlorinated biphenyls (PCBs) in blood and milk from free-ranging Southern Beaufort-Chukchi Sea polar bears (Ursus maritimus) to assess maternal transfer of contaminants during lactation and the potential health risk to nursing young. Concentrations of contaminants in the blood of dependent and juvenile animals (ages 1-5 years) ranged from 35.9 to 52.2 μg kg(-1) ww for tHg and 13.9 to 52.2 μg kg(-1) ww (3255.81-11067.79 μg kg(-1) lw) for ΣPCB(7)s, similar to those of adult females, but greater than adult males. Contaminant concentrations in milk ranged from 5.7 to 71.8 μg tHg kg(-1)ww and 160 to 690 μg ΣPCB(11)s kg(-1) ww (547-5190 μg kg(-1) lw). The daily intake levels for tHg by milk consumption estimated for dependent young were below the tolerable daily intake level (TDIL) of tHg established for adult humans. Although the daily intake levels of PCBs through milk consumption for cubs of the year exceeded the TDIL thresholds, calculated dioxin equivalents for PCBs in milk were below adverse physiological thresholds for aquatic mammals. Relatively high concentrations of non-dioxin like PCBs in polar bear milk and blood could impact endocrine function of Southern Beaufort-Chukchi Sea polar bears, but this is uncertain. Transfer of contaminants during mid to late lactation likely limits bioaccumulation of dietary contaminants in female polar bears during spring. As polar bears respond to changes in their arctic sea ice habitat, the adverse health impacts associated with nutritional stress may be exacerbated by tHg and PCBs exposure, especially in ecologically and toxicologically sensitive polar bear cohorts such as reproductive females and young. PMID:22464860

  4. When is arthritis reactive?

    Science.gov (United States)

    Hamdulay, S S; Glynne, S J; Keat, A

    2006-07-01

    Reactive arthritis is an important cause of lower limb oligoarthritis, mainly in young adults. It is one of the spondyloarthropathy family; it is distinguishable from other forms of inflammatory arthritis by virtue of the distribution of affected sites and the high prevalence of characteristic extra-articular lesions. Many terms have been used to refer to this and related forms of arthritis leading to some confusion. Reactive arthritis is precipitated by an infection at a distant site and genetic susceptibility is marked by possession of the HLA-B27 gene, although the mechanism remains uncertain. Diagnosis is a two stage process and requires demonstration of a temporal link with a recognised "trigger" infection. The identification and management of "sexually acquired" and "enteric" forms of reactive arthritis are considered. Putative links with HIV infection are also discussed. The clinical features, approach to investigation, diagnosis, and management of reactive arthritis are reviewed. PMID:16822921

  5. Long term prognosis of reactive salmonella arthritis

    OpenAIRE

    Leirisalo-Repo, M; Helenius, P; Hannu, T; Lehtinen, A; Kreula, J; Taavitsainen, M; Koskimies, S

    1997-01-01

    OBJECTIVES—Reactive joint complications triggered by salmonella gastroenteritis are increasingly reported, but the outcome and long term prognosis of the patients is incompletely known. This study looked at the prognosis of salmonella arthritis in patients hospitalised in 1970-1986.
METHODS—Hospital records from two hospitals in southern Finland were screened for patients with the discharge diagnosis of salmonellosis or reactive, postinfectious arthritis or Reiter's disease. For the patients ...

  6. Reactive sputter deposition

    CERN Document Server

    Mahieu, Stijn

    2008-01-01

    In this valuable work, all aspects of the reactive magnetron sputtering process, from the discharge up to the resulting thin film growth, are described in detail, allowing the reader to understand the complete process. Hence, this book gives necessary information for those who want to start with reactive magnetron sputtering, understand and investigate the technique, control their sputtering process and tune their existing process, obtaining the desired thin films.

  7. Reactive plasma spraying

    OpenAIRE

    Al-Sabouni, Omar

    1999-01-01

    Reactive Plasma Spraying (RPS) with a hydrocarbon gas has been studied as a method to improve the mechanical properties of a commercially available 80: 20 nickel-chromium alloy, and subsequently as a method to reduce the oxygen content of sprayed MCrAlY coatings. A conventional d. c. plasma torch has been modified by attaching a conical graphite tube (reactor) onto the end of the gun. The powder is then sprayed through the reactor with injected reactive hydrocarbon gas. The ...

  8. When is arthritis reactive?

    OpenAIRE

    Hamdulay, S. S.; Glynne, S J; Keat, A

    2006-01-01

    Reactive arthritis is an important cause of lower limb oligoarthritis, mainly in young adults. It is one of the spondyloarthropathy family; it is distinguishable from other forms of inflammatory arthritis by virtue of the distribution of affected sites and the high prevalence of characteristic extra‐articular lesions. Many terms have been used to refer to this and related forms of arthritis leading to some confusion. Reactive arthritis is precipitated by an infection at a distant site and gen...

  9. Interactive Chemical Reactivity Exploration

    OpenAIRE

    Haag, Moritz P.; Vaucher, Alain C.; Bosson, Mael; Redon, Stephane; Reiher, Markus

    2014-01-01

    Elucidating chemical reactivity in complex molecular assemblies of a few hundred atoms is, despite the remarkable progress in quantum chemistry, still a major challenge. Black-box search methods to find intermediates and transition-state structures might fail in such situations because of the high-dimensionality of the potential energy surface. Here, we propose the concept of interactive chemical reactivity exploration to effectively introduce the chemist's intuition into the search process. ...

  10. Polychlorinated biphenyls (PCB)-degrading bacteria associated with the trees in a PCB-contaminated site

    Czech Academy of Sciences Publication Activity Database

    Leigh, M. B.; Prouzová, P.; Macková, Martina; Macek, Tomáš; Nagle, D. P.; Fletcher, J. S.

    2006-01-01

    Roč. 72, č. 4 (2006), s. 2331-2342. ISSN 0099-2240 R&D Projects: GA ČR GA203/06/0563 Institutional research plan: CEZ:AV0Z40550506 Keywords : polychlorinated biphenyl Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides Impact factor: 3.532, year: 2006

  11. Preparation of plants containing bacterial enzyme for degradation of polychlorinated biphenyls

    Czech Academy of Sciences Publication Activity Database

    Francová, K.; Surá, M.; Macek, Tomáš; Szekeres, M.; Bancos, S.; Demnerová, K.; Sylvestre, M.; Macková, M.

    2003-01-01

    Roč. 12, č. 3 (2003), s. 309-313. ISSN 1018-4619 Institutional research plan: CEZ:AV0Z4055905 Keywords : transgenic plants * polychlorinated biphenyls * phytoremediation Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides Impact factor: 0.325, year: 2003

  12. Genomic characterization of three unique Dehalococcoides that respire on persistent polychlorinated biphenyls

    OpenAIRE

    Wang, Shanquan; Chng, Kern Rei; Wilm, Andreas; Zhao, Siyan; Yang, Kun-Lin; Nagarajan, Niranjan; HE, Jianzhong

    2014-01-01

    Polychlorinated biphenyls (PCBs) as persistent organic pollutants are widespread in the sediments of lakes, rivers, and harbors. Although the PCB detoxification through microbial reductive dechlorination has been extensively studied for more than 20 y, the difficulty in cultivating PCB dechlorinators in pure culture impedes further characterization, optimization, and application in in situ bioremediation. By combining traditional culture techniques with next-generation sequencing technology, ...

  13. Commentary on Polychlorinated Biphenyls (PCBs), Toxins, and Neuropsychological Deficits: Good Science is the Antidote

    Science.gov (United States)

    Hebben, Nancy

    2004-01-01

    The seven cohort studies of the relation between prenatal and postnatal exposure to polychlorinated biphenyls (PCBs) to cognitive, neuropsychological and behavioral development have suggested that exposure to PCBs can cause persistent changes in cognitive functioning. D.V. Cicchetti, A.S. Kaufman, and S.S. Sparrow (this issue) apply six scientific…

  14. A method for the chemical modification of polychlorinated biphenyls for improved affinity towards noble metal surfaces

    DEFF Research Database (Denmark)

    2015-01-01

    The present application discloses a method for the modification and analysis of a field sample suspected of containing contaminant(s) like polychlorinated biphenyls (PCBs). The invention also relates to a corresponding kit for the modification of samples suspected of containing such contaminant(s)....

  15. Contamination of free-range chicken eggs with dioxins and dioxin-like polychlorinated biphenyls

    NARCIS (Netherlands)

    Schoeters, G.; Hoogenboom, L.A.P.

    2006-01-01

    Dioxins and dioxin-like (DL) polychlorinated biphenyls (PCB) are persistent organic pollutants that enter the body mainly by food intake. A small margin exists between current exposure levels in the human population and the levels causing biological effects. Therefore, stringent control of concentra

  16. Polychlorinated biphenyls-induced alterations of thyroid hormone homeostasis and brain development in the rat.

    NARCIS (Netherlands)

    Morse, D.C.

    1995-01-01

    IntroductionThe work described in this thesis was undertaken to gain insight in the processes involved in the developmental neurotoxicity of polychlorinated biphenyls. It has been previously hypothesized that the alteration of thyroid hormone status by PCBs may be in part responsibl

  17. Synthesis and properties of a new diarylethene having thiazole and biphenyl moieties

    International Nuclear Information System (INIS)

    A novel photochromic diarylethene bearing thiazole and biphenyl moieties has been synthesized. Its properties, including photochromism and fluorescence were investigated in detail. It underwent reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light in hexane. The results showed that this compound exhibited reversible photochromism and good fluorescent switching in solution after irradiation with UV light and visible light.

  18. Synthesis and properties of a new diarylethene having thiazole and biphenyl moieties

    Energy Technology Data Exchange (ETDEWEB)

    Li Hui; Pu Shouzhi; Liu Gang; Liu Weijun, E-mail: pushouzhi@tsinghua.org.cn [Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang 330013 (China)

    2011-02-01

    A novel photochromic diarylethene bearing thiazole and biphenyl moieties has been synthesized. Its properties, including photochromism and fluorescence were investigated in detail. It underwent reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light in hexane. The results showed that this compound exhibited reversible photochromism and good fluorescent switching in solution after irradiation with UV light and visible light.

  19. Effect of highly bioaccumulated polychlorinated biphenyl congeners on estrogen and androgen receptor activity

    DEFF Research Database (Denmark)

    Bonefeld-Jørgensen, E.C.; Andersen, H. R.; Rasmussen, T.H.;

    2001-01-01

    in transiently co-transfected Chinese Hamster Ovary cells with an IC50, of 6.2 muM. In summary, this study indicate that the di-ortho, multiple-chloro substituted biphenyls, PCB # 138, PCB # 153 and PCB # 180, can compete with the binding of the natural ligand to two nuclear receptors and thus...

  20. Assessment of polychlorinated biphenyls and organochlorine pesticides in water samples from the Yamuna River

    OpenAIRE

    Bhupander Kumar; Satish Kumar Singh; Meenu Mishra; Sanjay Kumar; Chandra Shekhar Sharma

    2012-01-01

    Polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) are toxic, persistent and bioaccumulative long-range atmospheric transport pollutants. These are transported worldwide affecting remote regions far from their original sources, and can transfer into food webs with a wide range of acute and chronic health effects. India ratified the Stockholm Convention with the intention of reducing and eliminating persistent organic pollutants (POPs), and ...

  1. An efficient synthesis, X-ray and spectral characterization of biphenyl derivatives

    Indian Academy of Sciences (India)

    Ravindra R Kamble; Dharesh B Biradar; Gangadhar Y Meti; Tasneem Taj; Tegginamath Gireesh; Imthiyaz Ahmed M Khazi; Sundar T Vaidyanathan; Raju Mohandoss; Balasubramanian Sridhar; Viraraghav Parthasarathi

    2011-07-01

    Derivatives of 1,3-thiazolidin-2,4-dione appended to biphenyl ring viz., 7-9, 16-18 were prepared. The newly synthesized compounds were confirmed by IR, NMR (1H and 13C) MS and elemental analyses. Single crystal X-ray diffraction study was carried out for one of the final compounds 9.

  2. Immunologic effects of background exposure to polychlorinated biphenyls and dioxins in Dutch preschool children

    NARCIS (Netherlands)

    Weisglas-Kuperus, N; Patandin, S; Berbers, GAM; Sas, TCJ; Mulder, PGH; Sauer, PJJ; Hooijkaas, H

    2000-01-01

    Prenatal exposure to polychlorinated biphenyls (PCBs) and dioxins is associated with changes in the T-cell lymphocyte population in healthy Dutch infants. We investigated whether these changes persist into later childhood and whether background exposure to PCBs and dioxins is associated with the pre

  3. Modelling the impact of room temperature on concentrations of polychlorinated biphenyls (PCBs) in indoor air

    DEFF Research Database (Denmark)

    Lyng, Nadja; Clausen, Per Axel; Lundsgaard, Claus;

    2016-01-01

    Buildings contaminated with polychlorinated biphenyls (PCBs) are a health concern for the building occupants. Inhalation exposure is linked to indoor air concentrations of PCBs, which are known to be affected by indoor temperatures. In this study, a highly PCB contaminated room was heated to six...

  4. Polychlorinated biphenyl exposure alters the expression profile of microRNAs associated with vascular diseases.

    Science.gov (United States)

    Wahlang, Banrida; Petriello, Michael C; Perkins, Jordan T; Shen, Shu; Hennig, Bernhard

    2016-09-01

    Exposure to persistent organic pollutants, including polychlorinated biphenyls (PCBs) is correlated with multiple vascular complications including endothelial cell dysfunction and atherosclerosis. PCB-induced activation of the vasculature subsequently leads to oxidative stress and induction of pro-inflammatory cytokines and adhesion proteins. Gene expression of these cytokines/proteins is known to be regulated by small, endogenous oligonucleotides known as microRNAs that interact with messenger RNA. MicroRNAs are an acknowledged component of the epigenome, but the role of environmentally-driven epigenetic changes such as toxicant-induced changes in microRNA profiles is currently understudied. The objective of this study was to determine the effects of PCB exposure on microRNA expression profile in primary human endothelial cells using the commercial PCB mixture Aroclor 1260. Samples were analyzed using Affymetrix GeneChip® miRNA 4.0 arrays for high throughput detection and selected microRNA gene expression was validated (RT-PCR). Microarray analysis identified 557 out of 6658 microRNAs that were changed with PCB exposure (p<0.05). In-silico analysis using MetaCore database identified 21 of these microRNAs to be associated with vascular diseases. Further validation showed that Aroclor 1260 increased miR-21, miR-31, miR-126, miR-221 and miR-222 expression levels. Upregulated miR-21 has been reported in cardiac injury while miR-126 and miR-31 modulate inflammation. Our results demonstrated evidence of altered microRNA expression with PCB exposure, thus providing novel insights into mechanisms of PCB toxicity. PMID:27288564

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

    International Nuclear Information System (INIS)

    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

  6. Reproductive dysfunction in rhesus monkeys exposed to low levels of polychlorinated biphenyls (Aroclor 1248)

    Energy Technology Data Exchange (ETDEWEB)

    Barsotti, D.A.; Marlar, R.J.; Allen, J.R.

    1976-01-01

    Eighteen female and four male adult Rhesus monkeys were fed the polychlorinated biphenyl (PCB) Aroclor 1248 at levels of either 2.5 or 5.0 ppM in the diet. These levels are equal to, and 50% of, the concentration allowed in certain foods destined for human consumption. After consuming these diets for 2 months, some of the females developed acne, alopecia, erythema and swelling of the eyelids, and by 6 months all females exhibited these changes to some degree. Modifications in serum lipids developed gradually, with a trend towards hypocholesterolaemia, hypolipidaemia and decreased serum triglycerides. In addition there was a shift in the plasma albumin/globulin ratio and an increase in serum glutamic-pyruvic transaminase activity. Analysis of subcutaneous fat showed an accumulation of the PCB isomers in the adipose tissue. The concentrations in this tissue reached a plateau, after which only slight variations were observed. Within 4 months, menstrual cycles were altered: menostaxis and menorrhagia occurred frequently and at times amenorrhoea was apparent. The ability of the animals to maintain pregnancy was impaired, as indicated by frequent resorptions and abortions. When infants were born they were small, and the transplacental movement of PCBs was evident from analyses of skin biopsies of neonates and of autopsy tissue from one stillborn. Moreover, additional accumulation of PCBs occurred in infants during breast feeding. All males fed 5.0 ppM PCB exhibited only slight periorbital oedema and erythema after 14 months on the diet and showed no alterations in their breeding capacities. The data presented indicate that long-term, low-level exposure of female non-human primates to PCBs can affect many important biological parameters.

  7. Positron annihilation studies of 4-n-butyl-4'-isothiocyanato-1,1'-biphenyl.

    Science.gov (United States)

    Dryzek, E; Juszyńska, E; Zaleski, R; Jasińska, B; Gorgol, M; Massalska-Arodź, M

    2013-08-01

    Positron annihilation lifetime spectroscopy (PALS) measurements were performed between 93 and 293 K in order to study the supercooled smectic-E (Sm-E) phase of 4-n-butyl-4'-isothiocyanato-1,1'-biphenyl (4TCB), the ordered molecular crystal of 4TCB, and the phase transition between the Sm-E phase and the ordered molecular crystal of 4TCB. The phase transition was well reflected in the abrupt increase of the ortho-positronium (o-Ps) lifetime and intensity. The value of the o-Ps lifetime in the Sm-E liquid crystalline phase of 4TCB, i.e., 2.21 ns at room temperature, was explained by the formation of bubbles induced by Ps atoms, which are created due to a liquidlike state of the butyl chains of 4TCB molecules in the Sm-E phase. The temperature dependence of the o-Ps intensity for the supercooled Sm-E phase can be explained by thermal generation of sites where bubbles are formed; an activation energy equal to 0.30±0.02 eV was estimated. This value was compared with the activation energies of molecular motions. The o-Ps lifetime in the ordered molecular crystal was interpreted as originating from the annihilation of o-Ps confined in molecular vacancy-type imperfections in the crystal lattice. The value of the o-Ps pickoff annihilation between 1.8 and 1.9 ns is in accordance with the size of the molecular vacancy for the 4TCB crystal lattice. Its intensity is lower than 5%. The isothermal crystallization of the 4TCB Sm-E phase was observed by PALS. The low-dimensional crystal growth was concluded from the Avrami equation fitted to the time dependence of the o-Ps intensity, which resulted in an Avrami exponent equal to 1.73. PMID:24032853

  8. A cohort study of in utero polychlorinated biphenyl (PCB exposures in relation to secondary sex ratio

    Directory of Open Access Journals (Sweden)

    Keller Jean A

    2008-07-01

    Full Text Available Abstract Background Polychlorinated biphenyls (PCBs are ubiquitous industrial chemicals that persist in the environment and in human fatty tissue. PCBs are related to a class of compounds known as dioxins, specifically 2,3,7,8-TCDD (tetrachloro-dibenzodioxin, which has been implicated as a cause of altered sex ratio, especially in relation to paternal exposures. Methods In the 1960's, serum specimens were collected from pregnant women participating in the Child Health and Development Study in the San Francisco Bay Area. The women were interviewed and their serum samples stored at -20°C. For this study, samples were thawed and a total of eleven PCBs were determined in 399 specimens. Secondary sex ratio, or sex ratio at birth, was evaluated as a function of maternal serum concentrations using log-binomial and logistic regression, controlling for hormonally active medications taken during pregnancy. Results The relative risk of a male birth decreased by 33% comparing women at the 90th percentile of total PCBs with women at the 10th percentile (RR = 0.67; 95% CI, 0.48–0.94; p = 0.02, or by approximately 7% for each 1 μg/L increase in total PCB concentration. Although some congener-specific associations with sex ratio were only marginally statistically significant, all nine PCB congeners with Conclusion Maternal exposure to PCBs may be detrimental to the success of male sperm or to the survival of male embryos. Findings could be due to contaminants, metabolites or PCBs themselves.

  9. Subchronic oral toxicity in guinea pigs of soot from a polychlorinated biphenyl-containing transformer fire

    Energy Technology Data Exchange (ETDEWEB)

    DeCaprio, A.P.; McMartin, D.N.; Silkworth, J.B.; Rej, R.; Pause, R.; Kaminsky, L.S.

    1983-04-01

    The soot was determined to contain polychlorinated biphenyls, biphenylenes, dibenzodioxins, and dibenzofurans. The present study evaluates soot toxicity in guinea pigs receiving 0, 0.2, 1.9, 9.3, or 46.3 ppm soot in the feed for 90 days or 231.5 ppm for 32 days. At 231.5 ppm, body weight loss, thymic atrophy, bone marrow depletion, skeletal muscle and gastrointestinal tract epithelial degeneration, and fatty infiltration of hepatocytes were observed. Mortality had reached 35% by Day 32 (when survivors were killed), with total soot consumption of approximately 400 mg/kg. At 46.3 or 9.3 ppm soot, a reduced rate of body weight gain was observed, and at 46.3 ppm, the mortality by Day 90 was 30%. Relative (to body) thymus weights were decreased in both groups, while relative spleen weights were increased at 46.3 ppm soot only. Salivary gland interlobular duct squamous metaplasia and focal lacrimal gland adenitis were detected histopathologically, while bone marrow depletion was noted only in females at the higher dose. Diminished serum alanine aminotransferase (ALT) activity in both sexes and decreased serum sodium levels in male and potassium levels in female animals were detected at both dose levels. No effectse were noted in animals receiving 0.2 ppm soot for 90 days. Salivary gland duct metaplasia has not been previously reported. Toxic effects of this subchronic exposure were observed at lower total doses than with acute exposure, although variations in absorption due to the effects of different vehicles (aqueous in the acute study versus the feed in this study) could account for some or all of this difference.

  10. Predicting the bioaccumulation of polyaromatic hydrocarbons and polychlorinated biphenyls in benthic animals in sediments.

    Science.gov (United States)

    Tuikka, A I; Leppänen, M T; Akkanen, J; Sormunen, A J; Leonards, P E G; van Hattum, B; van Vliet, L A; Brack, W; Smedes, F; Kukkonen, J V K

    2016-09-01

    There were two main objectives in this study. The first was to compare the accuracy of different prediction methods for the chemical concentrations of polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the organism, based on the measured chemical concentrations existing in sediment dry matter or pore water. The predicted tissue concentrations were compared to the measured ones after 28-day laboratory test using oligochaeta worms (Lumbriculus variegatus). The second objective was to compare the bioaccumulation of PAHs and PCBs in the laboratory test with the in situ bioaccumulation of these compounds. Using the traditional organic carbon-water partitioning model, tissue concentrations were greatly overestimated, based on the concentrations in the sediment dry matter. Use of an additional correction factor for black carbon with a two-carbon model, significantly improved the bioaccumulation predictions, thus confirming that black carbon was important in binding the chemicals and reducing their accumulation. The predicted PAH tissue concentrations were, however, high compared to the observed values. The chemical concentrations were most accurately predicted from their freely dissolved pore water concentrations, determined using equilibrium passive sampling. The patterns of PCB and PAH accumulation in sediments for laboratory-exposed L. variegatus were similar to those in field-collected Lumbriculidae worms. Field-collected benthic invertebrates and L. variegatus accumulated less PAHs than PCBs with similar lipophilicity. The biota to sediment accumulation factors of PAHs tended to decrease with increasing sediment organic carbon normalized concentrations. The presented data yields bioconcentration factors (BCF) describing the chemical water-lipid partition, which were found to be higher than the octanol-water partition coefficients, but on a similar level with BCFs drawn from relevant literature. In conclusion, using the two-carbon model method

  11. Otters Increasing - Threats Increasing

    OpenAIRE

    Andreas Kranz

    1994-01-01

    In some parts of Central Europe populations of otters are apparently increasing. Until recently, no research was being conducted on the ecology of otters in mainly artificial habitats like fish farms. Otters are not only a new source of conflict requiring species management, but appear once again threatened by illegal hunting. Austria is dealing with this problem using compensation for otter damage, electric fencing and translocation of problem otters. Despite a rise in illegal killing, Austr...

  12. Digital reactivity meter

    International Nuclear Information System (INIS)

    Digital reactivity meters (DRM) are mostly used as measuring instruments, e.g. for calibration of control rods, and there are only a few cases of their incorporation into the control systems of the reactors. To move in this direction there is more development work needed. First of all, fast algorithms are needed for inverse kinetics equations to relieve the computer for more important tasks of reactor model solving in real time. The next problem, currently under investigation, is the incorporation of the reactor thermal-hydraulic model into the DRM so that it can be used in the power range. Such an extension of DHM allows presentation not only of the instantaneous reactivity of the system, but also the inserted reactivity can be estimated from the temperature reactivity feed-backs. One of the applications of this concept is the anomalous digital reactivity monitor (ADRN) as part of the reactor protection system. As a solution of the first problem, a fast algorithm for solving the inverse kinetics equations has been implemented in the off-line program RODCAL on CDC 1700 computer and tested for its accuracy by performing different control rod calibrations on the reactor TRIGA

  13. On reactive high power impulse magnetron sputtering

    Science.gov (United States)

    Gudmundsson, J. T.

    2016-01-01

    High power impulse magnetron sputtering (HiPIMS) is an ionized physical vapor deposition (IPVD) technique that is particularly promising for reactive sputtering applications. However, there are few issues that have to be resolved before the full potential of this technique can be realized. Here we give an overview of the key experimental findings for the reactive HiPIMS discharge. An increase in the discharge current is commonly observed with increased partial pressure of the reactive gas or decreased repetition pulse frequency. There are somewhat conflicting claims regarding the hysteresis effect in the reactive HiPIMS discharge as some report reduction or elimination of the hysteresis effect while others claim a feedback control is essential. The ion energy distribution of the metal ion and the atomic ion of the reactive gas are similar and extend to very high energies while the ion energy distribution of the working gas and the molecular ion of the reactive gas are similar and are much less energetic.

  14. The role of stress during memory reactivation on intrusive memories.

    Science.gov (United States)

    Cheung, Jessica; Garber, Benjamin; Bryant, Richard A

    2015-09-01

    Intrusive memories are unwanted recollections that maintain distress in psychological disorders. Increasing evidence suggests that memories that are reactivated through retrieval become temporarily vulnerable to environmental or pharmacological manipulation, including changes in levels of circulating stress hormones. This study investigated the influence of stress during memory reactivation of an emotionally arousing trauma film on subsequent intrusive memories. Three groups of participants (N=63) viewed a trauma film depicting a serious car accident at baseline. Two days later (Time 2), one group received a reactivation induction following a socially evaluated cold pressor test (SECPT; Stress/Reactivation condition), whilst the second group reactivated the memory after a control procedure (Reactivation condition). A third group underwent the SECPT but was not asked to reactivate memory of the trauma film (Stress condition). Two days later (Time 3), all participants received a surprise cued memory recall test and intrusions questionnaire which they completed online. Results showed that those in the Stress/Reactivation group had higher intrusions scores than the other two groups, suggesting that acute stress promotes intrusive memories only when the memory trace is reactivated shortly afterwards. Increased cortisol predicted enhanced intrusive experiences in the Stress/Reactivation condition but not in the other conditions. This pattern of results suggests that acute stress during the reactivation of emotional material impacts on involuntary emotional memories. These findings suggest a possible explanation for the mechanism underlying the maintenance of intrusive memories in clinical disorders. PMID:25911248

  15. Polychlorinated biphenyl 77 augments angiotensin II-induced atherosclerosis and abdominal aortic aneurysms in male apolipoprotein E deficient mice

    International Nuclear Information System (INIS)

    Infusion of angiotensin II (AngII) to hyperlipidemic mice augments atherosclerosis and causes formation of abdominal aortic aneurysms (AAAs). Each of these AngII-induced vascular pathologies exhibit pronounced inflammation. Previous studies demonstrated that coplanar polychlorinated biphenyls (PCBs) promote inflammation in endothelial cells and adipocytes, two cell types implicated in AngII-induced vascular pathologies. The purpose of this study was to test the hypothesis that administration of PCB77 to male apolipoprotein E (ApoE) −/− mice promotes AngII-induced atherosclerosis and AAA formation. Male ApoE−/− mice were administered vehicle or PCB77 (49 mg/kg, i.p.) during week 1 and 4 (2 divided doses/week) of AngII infusion. Body weights and total serum cholesterol concentrations were not influenced by administration of PCB77. Systolic blood pressure was increased in AngII-infused mice administered PCB77 compared to vehicle (156 ± 6 vs 137 ± 5 mmHg, respectively). The percentage of aortic arch covered by atherosclerotic lesions was increased in AngII-infused mice administered PCB77 compared to vehicle (2.0 ± 0.4 vs 0.9 ± 0.1%, respectively). Lumen diameters of abdominal aortas determined by in vivo ultrasound and external diameters of excised suprarenal aortas were increased in AngII-infused mice administered PCB77 compared to vehicle. In addition, AAA incidence increased from 47 to 85% in AngII-infused mice administered PCB77. Adipose tissue in close proximity to AAAs from mice administered PCB77 exhibited increased mRNA abundance of proinflammatory cytokines and elevated expression of components of the renin-angiotensin system (angiotensinogen, angiotensin type 1a receptor (AT1aR)). These results demonstrate that PCB77 augments AngII-induced atherosclerosis and AAA formation. -- Highlights: ► Polychlorinated biphenyl 77 (PCB77) promotes AngII-induced hypertension. ► PCB77 augments AngII-induced atherosclerosis. ► PCB77 promotes Ang

  16. Polychlorinated biphenyl 77 augments angiotensin II-induced atherosclerosis and abdominal aortic aneurysms in male apolipoprotein E deficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Arsenescu, Violeta [Graduate Center for Nutritional Sciences, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States); Arsenescu, Razvan [Digestive Diseases and Nutrition, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States); Parulkar, Madhura; Karounos, Michael [Graduate Center for Nutritional Sciences, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States); Zhang, Xuan [Graduate Center for Toxicology, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States); Baker, Nicki [Graduate Center for Nutritional Sciences, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States); Cassis, Lisa A., E-mail: lcassis@uky.edu [Graduate Center for Nutritional Sciences, University of Kentucky, 800 Rose Street, Lexington, KY 40536-0200 (United States)

    2011-11-15

    Infusion of angiotensin II (AngII) to hyperlipidemic mice augments atherosclerosis and causes formation of abdominal aortic aneurysms (AAAs). Each of these AngII-induced vascular pathologies exhibit pronounced inflammation. Previous studies demonstrated that coplanar polychlorinated biphenyls (PCBs) promote inflammation in endothelial cells and adipocytes, two cell types implicated in AngII-induced vascular pathologies. The purpose of this study was to test the hypothesis that administration of PCB77 to male apolipoprotein E (ApoE) -/- mice promotes AngII-induced atherosclerosis and AAA formation. Male ApoE-/- mice were administered vehicle or PCB77 (49 mg/kg, i.p.) during week 1 and 4 (2 divided doses/week) of AngII infusion. Body weights and total serum cholesterol concentrations were not influenced by administration of PCB77. Systolic blood pressure was increased in AngII-infused mice administered PCB77 compared to vehicle (156 {+-} 6 vs 137 {+-} 5 mmHg, respectively). The percentage of aortic arch covered by atherosclerotic lesions was increased in AngII-infused mice administered PCB77 compared to vehicle (2.0 {+-} 0.4 vs 0.9 {+-} 0.1%, respectively). Lumen diameters of abdominal aortas determined by in vivo ultrasound and external diameters of excised suprarenal aortas were increased in AngII-infused mice administered PCB77 compared to vehicle. In addition, AAA incidence increased from 47 to 85% in AngII-infused mice administered PCB77. Adipose tissue in close proximity to AAAs from mice administered PCB77 exhibited increased mRNA abundance of proinflammatory cytokines and elevated expression of components of the renin-angiotensin system (angiotensinogen, angiotensin type 1a receptor (AT1aR)). These results demonstrate that PCB77 augments AngII-induced atherosclerosis and AAA formation. -- Highlights: Black-Right-Pointing-Pointer Polychlorinated biphenyl 77 (PCB77) promotes AngII-induced hypertension. Black-Right-Pointing-Pointer PCB77 augments Ang

  17. Interactive Chemical Reactivity Exploration

    CERN Document Server

    Haag, Moritz P; Bosson, Mael; Redon, Stephane; Reiher, Markus

    2014-01-01

    Elucidating chemical reactivity in complex molecular assemblies of a few hundred atoms is, despite the remarkable progress in quantum chemistry, still a major challenge. Black-box search methods to find intermediates and transition-state structures might fail in such situations because of the high-dimensionality of the potential energy surface. Here, we propose the concept of interactive chemical reactivity exploration to effectively introduce the chemist's intuition into the search process. We employ a haptic pointer device with force-feedback to allow the operator the direct manipulation of structures in three dimensions along with simultaneous perception of the quantum mechanical response upon structure modification as forces. We elaborate on the details of how such an interactive exploration should proceed and which technical difficulties need to be overcome. All reactivity-exploration concepts developed for this purpose have been implemented in the Samson programming environment.

  18. DFT Studies of SN2 Dechlorination of Polychlorinated Biphenyls.

    Science.gov (United States)

    Krzemińska, Agnieszka; Paneth, Piotr

    2016-06-21

    Nucleophilic dechlorination of all 209 PCBs congeners by ethylene glycol anion has been studied theoretically at the DFT level. The obtained Gibbs free energies of activation are in the range 7-22 kcal/mol. The reaction Gibbs free energies indicate that all reactions are virtually irreversible. Due to geometric constrains these reactions undergo rather untypical attack with attacking oxygen atom being nearly perpendicular to the attacked C-Cl bond. The most prone to substitution are chlorine atoms that occupy ortho- (2, 2', 6, 6') positions. These results provide extensive information on the PEG/KOH dependent PCBs degradation. They can also be used in further developments of reaction class transition state theory (RC-TST) for description of complex reactive systems encountered for example in combustion processes. PMID:27244043

  19. Effect of Quercetin on Haematobiochemical and Histological Changes in the Liver of Polychlorined Biphenyls-Induced Adult Male Wistar Rats

    Directory of Open Access Journals (Sweden)

    Kandaswamy Selvakumar

    2013-01-01

    Full Text Available Polychlorinated biphenyls exposure damages the rat liver cells. Hematological parameters such as hemoglobin, packed cell volume, red-blood cells, white-blood cells, neutrophils, platelet counts, and RBC indices were significantly decreased. Polymorphs, eosinophil counts, and erythrocyte sedimentation rate were significantly increased. Serum liver enzymes such as aspartate transaminase, alanine transaminase, alkaline phosphatase, and gamma-glutamyl transferase were increased by PCBs treatment. Serum lipid profiles such as cholesterol, triglycerides, low-density lipoproteins and very-low-density lipoproteins were increased in PCBs-treated rats. High-density lipoprotein, total protein, albumin, globulin levels, and albumin/globulin ratio were also decreased after PCB exposure. Then levels of sodium, potassium, chloride, and bicarbonate were also altered. Serum glucose levels were increased along with total bilirubin after PCBs exposure. Simultaneous quercetin supplementation significantly protected the PCBs-induced changes of hematobiochemical parameters. Thus, quercetin shows a protective role against PCBs-induced alterations in the hematological and biochemical parameters.

  20. Pay-as-bid based reactive power market

    Energy Technology Data Exchange (ETDEWEB)

    Amjady, N. [Department of Electrical Engineering, Semnan University, Semnan (Iran, Islamic Republic of); Rabiee, A., E-mail: Rabiee@iust.ac.i [Center of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Shayanfar, H.A. [Center of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

    2010-02-15

    In energy market clearing, the offers are stacked in increasing order and the offer that intersects demand curve, determines the market clearing price (MCP). In reactive power market, the location of reactive power compensator is so important. A low cost reactive producer may not essentially be favorable if it is far from the consumer. Likewise, a high cost local reactive compensator at a heavily loaded demand center of network could be inevitably an alternative required to produce reactive power to maintain the integrity of power system. Given the background, this paper presents a day-ahead reactive power market based on pay-as-bid (PAB) mechanism. Generators expected payment function (EPF) is used to construct a bidding framework. Then, total payment function (TPF) of generators is used as the objective function of optimal power flow (OPF) problem to clear the PAB based market. The CIGRE-32 bus test system is used to examine the effectiveness of the proposed reactive power market.

  1. Pay-as-bid based reactive power market

    International Nuclear Information System (INIS)

    In energy market clearing, the offers are stacked in increasing order and the offer that intersects demand curve, determines the market clearing price (MCP). In reactive power market, the location of reactive power compensator is so important. A low cost reactive producer may not essentially be favorable if it is far from the consumer. Likewise, a high cost local reactive compensator at a heavily loaded demand center of network could be inevitably an alternative required to produce reactive power to maintain the integrity of power system. Given the background, this paper presents a day-ahead reactive power market based on pay-as-bid (PAB) mechanism. Generators expected payment function (EPF) is used to construct a bidding framework. Then, total payment function (TPF) of generators is used as the objective function of optimal power flow (OPF) problem to clear the PAB based market. The CIGRE-32 bus test system is used to examine the effectiveness of the proposed reactive power market.

  2. Hybrid pseudomonads engineered by two-step homologous recombination acquire novel degradation abilities toward aromatics and polychlorinated biphenyls

    Energy Technology Data Exchange (ETDEWEB)

    Suenaga, Hikaru [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan). Bioproduction Research Inst.; Nonaka, Kazuhiko; Goto, Masatoshi [Kyushu Univ., Fukuoka (Japan). Dept. of Bioscience and Biotechnology; Fujihara, Hidehiko; Furukawa, Kensuke [Beppu Univ. (Japan). Dept. of Fermentation and Food Science

    2010-10-15

    Pseudomonas pseudoalcaligenes KF707 possesses a chromosomally encoded bph gene cluster responsible for the catabolism of biphenyl and polychlorinated biphenyls. Previously, we constructed chimeric versions of the bphA1 gene, which encodes a large subunit of biphenyl dioxygenase, by using DNA shuffling between bphA1 genes from P. pseudoalcaligenes KF707 and Burkholderia xenovorans LB400. In this study, we demonstrate replacement of the bphA1 gene with chimeric bphA1 sequence within the chromosomal bph gene cluster by two-step homologous recombination. Notably, some of the hybrid strains acquired enhanced and/or expanded degradation capabilities for specific aromatic compounds, including single aromatic hydrocarbons and polychlorinated biphenyls. (orig.)

  3. Draft Genome Sequence of Polychlorinated Biphenyl-Dechlorinating Dehalococcoides mccartyi Strain SG1, Which Carries a Circular Putative Plasmid

    OpenAIRE

    Wang, Shanquan; Chng, Kern Rei; Wu, Chen; Wilm, Andreas; Nagarajan, Niranjan; HE, Jianzhong

    2014-01-01

    Dehalococcoides mccartyi strain SG1, isolated from digester sludge, dechlorinates polychlorinated biphenyls (PCBs) to lower congeners. Here we report the draft genome sequence of SG1, which carries a 22.65 kbp circular putative plasmid.

  4. Proof of concept for the use of macroinvertebrates as indicators of polychlorinated biphenyls (PCB) contamination in Lake Hartwell

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) has been conducting research to develop methods and tools for the evaluation of monitored natural recovery (MNR) of sediments contaminated with polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and other lega...

  5. Mixed function oxidase dependent biotransformation of polychlorinated biphenyls by different species of fish from the North Sea

    DEFF Research Database (Denmark)

    Mehrtens, G.; Laturnus, F.

    1999-01-01

    Mixed function oxidase (MFO) dependent biotransformation of polychlorinated biphenyls (PCBs) was measured in three different fish species from the North Sea. Liver microsomes of plaice (Pleuronectes platessa), dab (Limanda limanda) and cod (Gadus morhua) were isolated and incubated with different...

  6. Environmental exposure to polychlorinated biphenyls (PCBs) and dioxins : Consequences for longterm neurological and cognitive development of the child lactation

    NARCIS (Netherlands)

    Boersma, ER; Lanting, Caren; Koletzko, B; Michaelsen, KF; Hernell, O

    2000-01-01

    Polychlorinated biphenyls (PCBs) and dioxins are environmental pollutants. Prenatally, as well as postnatally through breast feeding, large amounts are transferred from mother to the child. Formula is free of these substances. Considering their potential developmental neurotoxicity, we investigated

  7. Production of metabolites from chloro biphenyls by resting cells of Pseudomonas strain LB400 after growth on different carbon sources

    International Nuclear Information System (INIS)

    The transformation of polychlorinated biphenyl (PCB), when exposed to microorganisms, into chlorobenzoic acid metabolites was studied. PCBs are widely used in electrical transformers and have become widely dispersed in the environment. A proposed system for clean up of PCBs involves the combined use of anaerobic reductive dehalogenation of highly chlorinated congeners followed by aerobic degradation of moderately chlorinated PCBs, mediated by oxidative ring attack. Much of this work focused on biphenyl-grown cells, in particular Pseudomonas strain LB400 grown on biphenyl, which contains a multicomponent enzyme system. It was shown that resting cells of Pseudomonas strain LB400, grown on glycerol or glucose, could also transform purified PCB congeners and mixtures of PCBs in Aroclors, however, transformation rates were less than those observed with biphenyl-grown cells. 29 refs., 2 tabs., 2 figs

  8. Congener specific effects by polychlorinated biphenyls on catecholamine content and release in chromaffin cells

    Energy Technology Data Exchange (ETDEWEB)

    Messeri, M.D. [Medizinisches Institut fuer Umwelthygiene an der Heinrich-Heine-Univ., Duesseldorf (Germany); Bickmeyer, U. [Medizinisches Institut fuer Umwelthygiene an der Heinrich-Heine-Univ., Duesseldorf (Germany); Weinsberg, F. [Physiologisches Institut, Universitaetskrankenhaus Hamburg Eppendorf, Martinistasse 52, D-20246 Hamburg (Germany); Wiegand, H. [Medizinisches Institut fuer Umwelthygiene an der Heinrich-Heine-Univ., Duesseldorf (Germany)

    1997-05-01

    The effects of the non-planar polychlorinated biphenyl (PCB) congener 2,2`,4,4`-tetrachlorobiphenyl (2,4-TCB) and of the coplanar PCB congener 3,3`,4,4`-tetrachlorobiphenyl (3,4-TCB) were investigated on the catecholamine content and release from bovine adrenal chromaffin cells in culture. Each congener was tested at three concentrations (20, 50 and 100 {mu}M) and two exposure periods (24 h and 5 days). Catecholamine release induced by K{sup +}-stimulation as well as catecholamine content of Triton X-100 treated cell cultures were examined using high-performance liquid chromatography (HPLC). 2,4-TCB showed dose- and time-dependent effects. 2,4-TCB at 100 {mu}M reduced the K{sup +}-stimulated catecholamine release after 24 h of exposure. After 5 days of exposure, 2,4 TCB at 50 and 100 {mu}M drastically reduced the K{sup +}-stimulated catecholamine release. 3,4-TCB even at a concentration of 100 {mu}M over exposure of either 24 h or 5 days had no effects on the K{sup +}-stimulated secretion. When chromaffin cells, exposed to 2,4-TCB, were lysed with 0.5% Triton X-100, a dose- and time-dependent reduction of the catecholamine content appeared. The 3,4-TCB did not reduce the catecholamine content. Conversely there seemed to be a trend towards an increase in catecholamine content. Spontaneous release of catecholamines was strongly increased by the non-planar 2,4 TCB, while the coplanar 3,4 TCB showed no effects on this parameter. Furthermore, the effects of 2,4 TCB appeared to be reversible after replacing the highest concentration (100 {mu}M) of the TCB-solution with culture-medium at the end of the 24-h exposure. Thus, K{sup +}-stimulated catecholamine release and the catecholamine content of bovine adrenal chromaffin cells was effectively reduced by the non-planar PCB congener whereas spontaneous catecholamine release was strongly increased. The coplanar PCB congener was ineffective at the same conditions. (orig.). With 5 figs., 2 tabs.

  9. Rapid Detection of Polychlorinated Biphenyls at Trace Levels in Real Environmental Samples by Surface-Enhanced Raman Scattering

    OpenAIRE

    Zhengjun Zhang; Yu Huang; Zhengcao Li; Xian Zhang; Qin Zhou

    2011-01-01

    Detection of trace levels of persistent pollutants in the environment is difficult but significant. Organic pollutant homologues, due to their similar physical and chemical properties, are even more difficult to distinguish, especially in trace amounts. We report here a simple method to detect polychlorinated biphenyls (PCBs) in soil and distilled spirit samples by the surface-enhanced Raman scattering technique using Ag nanorod arrays as substrates. By this method, polychlorinated biphenyls ...

  10. Stimulation of contraction of pregnant rat uterus in vitro by non-dechlorinated and microbially dechlorinated mixtures of polychlorinated biphenyls.

    OpenAIRE

    BAE, J.; Mousa, M A; Quensen, J F; Boyd, S A; Loch-Caruso, R

    2001-01-01

    A previous study of six polychlorinated biphenyl (PCB) congeners showed that PCBs with four or fewer chlorines and ortho substitution stimulate uterine contraction frequency in vitro, whereas congeners with a greater number of chlorines or non-ortho substitution are inactive in vitro. We tested the hypothesis that PCB mixtures stimulate uterine contractions in a manner inversely related to the degree of chlorination and the presence of chlorines in the ortho- position of the biphenyl constitu...

  11. Energy transfer in reactive and non-reactive H2 + OH collisions

    International Nuclear Information System (INIS)

    We have used the methods of quasi-classical dynamics to compute energy transfer properties of non-reactive and reactive H2 + OH collisions. Energy transfer has been investigated as function of translational temperature, reagent rotational energy, and reagent vibrational energy. The energy transfer mechanism is complex with ten types of energy transfer possible, and evidence was found for all types. There is much more exchange between the translational degree of freedom and the H2 vibrational degree of freedom than there is between translation and OH vibration. Translational energy is transferred to the rotational degrees of freedom of each molecule. There is a greater propensity for the transfer of translation to OH rotation than H2 rotation. In reactive collisions, increases in reagent translational temperature predominantly appear as vibrational energy in the water molecule. Energy transfer in non-reactive and reactive collisions does not depend strongly on the initial angular momentum in either molecule. In non-reactive collisions, vibrational energy is transferred to translation, to the rotational degree of freedom of the same molecule, and to the rotational and vibrational degrees of freedom of the other molecule. In reactive collisions, the major effect of increasing the vibrational energy in reagent molecules is that, on the average, the vibrational energy of the reagents appears as product vibrational energy. 18 refs., 16 figs., 6 tabs

  12. Hydroxyquinones: Synthesis and Reactivity

    Directory of Open Access Journals (Sweden)

    Spyros Spyroudis

    2000-12-01

    Full Text Available Quinones having hydroxy groups directly attached to the quinone ring constitute a very interesting class of quinoid compounds. A great number of hydroxyquinones are found in nature and the majority of them exhibit unique biological activity. Their syntheses and their main reactivity patterns are reviewed in this paper.

  13. C-reactive protein

    Science.gov (United States)

    C-reactive protein (CRP) is produced by the liver. The level of CRP rises when there is inflammation throughout the body. It is one of a group of proteins called "acute phase reactants" that go up in response to inflammation. ...

  14. Clojure reactive programming

    CERN Document Server

    Borges, Leonardo

    2015-01-01

    If you are a Clojure developer who is interested in using Reactive Programming to build asynchronous and concurrent applications, this book is for you. Knowledge of Clojure and Leiningen is required. Basic understanding of ClojureScript will be helpful for the web chapters, although it is not strictly necessary.

  15. Modelling reactive distillation

    NARCIS (Netherlands)

    Taylor, R.; Krishna, R.

    2000-01-01

    The design and operation issues for reactive distillation systems are considerably more complex than those involved for either conventional reactors or conventional distillation columns. The introduction of an in situ separation function within the reaction zone leads to complex interactions between

  16. Hexabromocyclododecanes, polybrominated diphenyl ethers, and polychlorinated biphenyls in radiometrically dated sediment cores from English lakes, ~1950-present.

    Science.gov (United States)

    Yang, Congqiao; Rose, Neil L; Turner, Simon D; Yang, Handong; Goldsmith, Ben; Losada, Sara; Barber, Jonathan L; Harrad, Stuart

    2016-01-15

    This paper reports input fluxes between ~1950 and present, of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and hexabromocyclododecanes (HBCDs) in radiometrically-dated sediment cores from 7 English lakes. Fluxes of PCBs at all but one location prone to significant sediment resuspension peaked in the late-1960s/early-1990s, before declining thereafter. Input fluxes of HBCDs at all sites increased from first emergence in the mid-1960s. Thereafter, fluxes peaked in the late-1980s/early-2000s, before declining through to the present, except at the most urban site where HBCD fluxes are still increasing. Trends of PBDEs predominant in the Penta-BDE and Octa-BDE formulations vary between sites. While at some locations, fluxes peaked in the late-1990s/early-2000s; at others, fluxes are still increasing. This suggests the full impact of EU restrictions on these formulations has yet to be felt. Fluxes of BDE-209 have yet to peak at all except one location, suggesting little discernible environmental response to recent EU restrictions on the Deca-BDE product. Strikingly, fluxes of BDE-209 in the most recent core slices either exceed or approach peak fluxes of ΣPCBs, implying substantial UK use of Deca-BDE. Excepting HBCDs, inventories of our target contaminants correlated significantly with local population density, implying substantial urban sources. PMID:26433331

  17. Comparison of 2,2',4,4',5,5'-hexachloro[14C]biphenyl levels in different adipose tissues of dogs and monkeys

    International Nuclear Information System (INIS)

    The polychlorinated biphenyl isomer, 2,2',4,4',5,5'-hexachloro[14C]biphenyl (2,4,5-HCB) was administered as a single iv dose at 0.6 mg/kg to dogs and monkeys. Adipose tissue, which included omentum, pericardial, perirenal, peritesticular, and subcutaneous fat, and blood were collected at various termination times and analyzed for total 14C and the parent hexachlorobiphenyl (HCB). Significant differences (p less than 0.0005) in the total hexachlorobiphenyl concentration as measured by total radioactivity (14C equivalents) were noted in the various adipose tissues and in the same adipose tissues with time. Peritesticular fat was consistently lower in the concentration of 14C equivalents than the other adipose tissues, which were nearly equal. The concentrations in subcutaneous fat samples were inconsistent. Total 14C equivalent concentrations in the adipose tissues either peaked or reached a maximum at Day 1 and Day 4 for dog and monkey, respectively. However, parent HCB fat/blood ratios continually increased over the time course of the experiment, because concentrations in blood decreased more rapidly than those in adipose tissue

  18. Reduction of thyroid hormone levels by methylsulfonyl metabolites of polychlorinated biphenyl congeners in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Yoshihisa; Shibahara, Tomoo; Kimura, Ryohei [School of Pharmaceutical Sciences, University of Shizuoka (Japan); Haraguchi, Koichi; Masuda, Yoshito [Daiichi College of Pharmaceutical Sciences, Fukuoka (Japan)

    1998-07-01

    Male Sprague-Dawley rats received four consecutive intraperitoneal doses of four kinds of methylsulfonyl (MeSO{sub 2}) metabolites of polychlorinated biphenyl (PCB) congeners: 3-MeSO{sub 2}-2,2`,3`,4`,5,6-hexachlorobiphenyl (3-MeSO{sub 2}-CB132); 3-MeSO{sub 2}-2,2`,3`,4`, 5,5`-hexachlorobiphenyl (3-MeSO{sub 2}-CB141); 3-MeSO{sub 2}-2,2`,4`,5,5`,6-hexachlorobiphenyl (3-MeSO{sub 2}-CB149) and 4-MeSO{sub 2}-2,2`,4`,5,5`,6-hexachlorobiphenyl (4-MeSO{sub 2}-CB149). The congeners were major MeSO{sub 2}-PCBs determined in human milk, liver and adipose tissue, and the aim was to determine their effect on thyroid hormone levels. All four tested MeSO{sub 2} metabolites (20 {mu}mol/kg once daily for 4 days) reduced serum total thyroxine levels by 22-44% at a much lower dose than phenobarbital (PB; 431 {mu}mol/kg once daily for 4 days) on days 2, 3, 4 and 7 after the final doses. Total triiodothyronine levels were reduced 37% by treatment with 4-MeSO{sub 2}-CB149 at day 7. A 30% increase in thyroid weight was produced by 3-MeSO{sub 2}-CB141 treatment. Total cytochrome P450 content was increased by 3-MeSO{sub 2}-CB132, 3-MeSO{sub 2}-CB141 and 3-MeSO{sub 2}-CB149, but not by 4-MeSO{sub 2}-CB149. Thus, it is likely that the 3-MeSO{sub 2}-hexachlorobiphenyls and 4-MeSO{sub 2}-CB149 could influence the thyroid hormone metabolism by different mechanism(s). The results show that tested 3- and 4-MeSO{sub 2} metabolites of PCB congeners reduce thyroid hormone levels much more than PB in rats. Our finding suggests that the metabolites may act as endocrine-disrupters. (orig.) With 2 figs., 1 tab., 25 refs.

  19. Omega-3 fatty acid oxidation products prevent vascular endothelial cell activation by coplanar polychlorinated biphenyls

    International Nuclear Information System (INIS)

    Coplanar polychlorinated biphenyls (PCBs) may facilitate development of atherosclerosis by stimulating pro-inflammatory pathways in the vascular endothelium. Nutrition, including fish oil-derived long-chain omega-3 fatty acids, such as docosahexaenoic acid (DHA, 22:6ω-3), can reduce inflammation and thus the risk of atherosclerosis. We tested the hypothesis that cyclopentenone metabolites produced by oxidation of DHA can protect against PCB-induced endothelial cell dysfunction. Oxidized DHA (oxDHA) was prepared by incubation of the fatty acid with the free radical generator 2,2-azo-bis(2-amidinopropane) dihydrochloride (AAPH). Cellular pretreatment with oxDHA prevented production of superoxide induced by PCB77, and subsequent activation of nuclear factor-κB (NF-κB). A4/J4-neuroprostanes (NPs) were identified and quantitated using HPLC ESI tandem mass spectrometry. Levels of these NPs were markedly increased after DHA oxidation with AAPH. The protective actions of oxDHA were reversed by treatment with sodium borohydride (NaBH4), which concurrently abrogated A4/J4-NP formation. Up-regulation of monocyte chemoattractant protein-1 (MCP-1) by PCB77 was markedly reduced by oxDHA, but not by un-oxidized DHA. These protective effects were proportional to the abundance of A4/J4 NPs in the oxidized DHA sample. Treatment of cells with oxidized eicosapentaenoic acid (EPA, 20:5ω-3) also reduced MCP-1 expression, but less than oxDHA. Treatment with DHA-derived cyclopentenones also increased DNA binding of NF-E2-related factor-2 (Nrf2) and downstream expression of NAD(P)H:quinone oxidoreductase (NQO1), similarly to the Nrf-2 activator sulforaphane. Furthermore, sulforaphane prevented PCB77-induced MCP-1 expression, suggesting that activation of Nrf-2 mediates the observed protection against PCB77 toxicity. Our data implicate A4/J4-NPs as mediators of omega-3 fatty acid-mediated protection against the endothelial toxicity of coplanar PCBs.

  20. Effects of perinatal coexposure to methylmercury and polychlorinated biphenyls on neurobehavioral development in mice

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, Norio [Tohoku University School of Medicine, Environmental Health Sciences, Aoba-ku, Sendai (Japan); Hirosaki University Graduate School of Medicine, Department of Neuropsychiatry, Hirosaki (Japan); Ohba, Takashi; Nakai, Kunihiko; Nakamura, Tomoyuki; Suzuki, Keita; Kameo, Satomi; Shimada, Miyuki; Kurokawa, Naoyuki; Satoh, Chieko; Satoh, Hiroshi [Tohoku University School of Medicine, Environmental Health Sciences, Aoba-ku, Sendai (Japan); Kakita, Akiyoshi [Niigata University, Department of Pathological Neuroscience, Resource Branch for Brain Disease Research, Brain Research Institute, Niigata (Japan)

    2008-06-15

    Methylmercury (MeHg) and polychlorinated biphenyls (PCBs) are environmental pollutants that cause neurobehavioral deficits in humans. Because exposures to MeHg and PCBs occur through fish consumption, it is necessary to clarify the effects of the interaction of the two pollutants. Therefore, we investigated the effects of perinatal exposure to MeHg and PCBs on the neurobehavioral development in mice. Female mice (C57BL/6Cr) were divided into four groups according to the type of exposure: (1) vehicle control, (2) MeHg alone, (3) PCBs alone, and (4) MeHg + PCBs. The MeHg-exposed groups were fed with a diet containing 5 ppm MeHg (as Hg), from 4 weeks before mating, throughout pregnancy, and lactation. The PCB-exposed groups were given a commercial mixture of PCBs, Aroclor 1254, at 18 mg/kg body weight in corn oil by gavage every 3 days from day 5 after breeding and continued until postnatal day (PND) 20. Before weaning, an assessment of eye opening showed the interactive effects between MeHg and PCBs on PND 12: The coexposure group showed a similar response to the control group, whereas the MeHg- and PCB-exposed groups showed a high response than the former two groups. We also observed delay in development of grasp reflex by MeHg exposure on PNDs 12 and 14. When the offspring mice were 8 weeks old, the group exposed to PCBs alone showed increases in the frequencies of excrement defecation and urine traces in an open-field test. Analysis of the latency revealed the antagonistic interaction between the MeHg and PCBs: The latency increased by either MeHg or PCB exposure was decreased by coexposure. Treatment with MeHg decreased the distance walked by the mice, and MeHg interacted with PCBs. Moris' water maze test showed that the MeHg-treated mice took a long time to reach the submerged platform; however, this MeHg exposure showed no interaction with PCB exposure. The spontaneous locomotion activity of the mice was not affected by the chemical exposure at 9 weeks of

  1. Relationships of Polychlorinated Biphenyls and Dichlorodiphenyldichloroethylene (p,p’-DDE) with Testosterone Levels in Adolescent Males

    Science.gov (United States)

    Gallo, Mia V.; Deane, Glenn D.; Nelder, Kyrie R.; DeCaprio, Anthony P.; Jacobs, Agnes

    2013-01-01

    Background: Concern persists over endocrine-disrupting effects of persistent organic pollutants (POPs) on human growth and sexual maturation. Potential effects of toxicant exposures on testosterone levels during puberty are not well characterized. Objectives: In this study we evaluated the relationship between toxicants [polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p´-DDE), hexachlorobenzene (HCB), and lead] and testosterone levels among 127 Akwesasne Mohawk males 10 to DeCaprio AP, Jacobs A; Akwesasne Task Force on the Environment. 2014. Relationships of polychlorinated biphenyls and dichlorodiphenyldichloroethylene (p,p´-DDE) with testosterone levels in adolescent males. Environ Health Perspect 122:304–309; http://dx.doi.org/10.1289/ehp.1205984 PMID:24398050

  2. Studies on the transformation of selected polychlorinated biphenyl congeners by Pseudomonas strain LB 400

    International Nuclear Information System (INIS)

    Some of the main factors influencing the degradation of certain PCB congeners by resting cells of Pseudomonas strain LB 400 were characterized. The significance of the carbon source used for growth was studied by comparison of rates of PCB transformation by cells grown on biphenyl and other carbon sources. PCB transformation was studied in resting cells grown on glucose and glycerol. Supplementation of the degradation medium with biphenyl significantly decreased the rate of PCB congener transformation. The presence of glycerol or glucose did not affect PCB transformation rates. The study showed that in the treatment of contaminated soils, resting cells lose their viability and PCB transforming ability, such that, in the absence of a growth substrate, soil would have to be reinoculated to maintain PCB biodegradation. 15 refs., 2 tabs., 5 figs

  3. Reactivity Network: Secondary Sources for Inorganic Reactivity Information.

    Science.gov (United States)

    Mellon, E. K.

    1989-01-01

    Provides an eclectic annotated bibliography of secondary sources for inorganic reactivity information of interest to reactivity network review authors and to anyone seeking information about simple inorganic reactions in order to develop experiments and demonstrations. Gives 119 sources. (MVL)

  4. Metabolism of chlorobiphenyls by a variant biphenyl dioxygenase exhibiting enhanced activity toward dibenzofuran

    International Nuclear Information System (INIS)

    Highlights: ► Burkholderia xenovorans LB400 biphenyl dioxygenase (BphAELB400) metabolizes PCBs. ► Asn338Gln/Leu409Phe double mutation speeds up electron transfer of enzyme reaction. ► We tested how the mutations affect the PCB-degrading abilities of BphAELB400 variants. ► The same mutations also broaden the PCB substrate range of BphAELB400 variants. -- Abstract: The biphenyl dioxygenase of Burkholderia xenovorans LB400 (BphAELB400) catalyzes the dihydroxylation of biphenyl and of several polychlorinated biphenyls (PCBs) but it poorly oxidizes dibenzofuran. In this work we showed that BphAERR41, a variant which was previously found to metabolize dibenzofuran more efficiently than its parent BphAELB400, metabolized a broader range of PCBs than BphAELB400. Hence, BphAERR41 was able to metabolize 2,6,2′,6′-, 3,4,3′,5′- and 2,4,3′,4′-tetrachlorobiphenyl that BphAELB400 is unable to metabolize. BphAERR41 was obtained by changing Thr335Phe336Asn338Ile341Leu409 of BphAELB400 to Ala335Met336Gln338Val341Phe409. Site-directed mutagenesis was used to create combinations of each substitution, in order to assess their individual contributions. Data show that the same Asn338Glu/Leu409Phe substitution that enhanced the ability to metabolize dibenzofuran resulted in a broadening of the PCB substrates range of the enzyme. The role of these substitutions on regiospecificities toward selected PCBs is also discussed.

  5. Metabolism of chlorobiphenyls by a variant biphenyl dioxygenase exhibiting enhanced activity toward dibenzofuran

    Energy Technology Data Exchange (ETDEWEB)

    Viger, Jean-Francois; Mohammadi, Mahmood; Barriault, Diane [Institut National de la Recherche Scientifique, INRS-Institut Armand-Frappier, Laval, Quebec, Canada H4K 1C2 (Canada); Sylvestre, Michel, E-mail: Michel.Sylvestre@iaf.inrs.ca [Institut National de la Recherche Scientifique, INRS-Institut Armand-Frappier, Laval, Quebec, Canada H4K 1C2 (Canada)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer Burkholderia xenovorans LB400 biphenyl dioxygenase (BphAE{sub LB400}) metabolizes PCBs. Black-Right-Pointing-Pointer Asn338Gln/Leu409Phe double mutation speeds up electron transfer of enzyme reaction. Black-Right-Pointing-Pointer We tested how the mutations affect the PCB-degrading abilities of BphAE{sub LB400} variants. Black-Right-Pointing-Pointer The same mutations also broaden the PCB substrate range of BphAE{sub LB400} variants. -- Abstract: The biphenyl dioxygenase of Burkholderia xenovorans LB400 (BphAE{sub LB400}) catalyzes the dihydroxylation of biphenyl and of several polychlorinated biphenyls (PCBs) but it poorly oxidizes dibenzofuran. In this work we showed that BphAE{sub RR41}, a variant which was previously found to metabolize dibenzofuran more efficiently than its parent BphAE{sub LB400}, metabolized a broader range of PCBs than BphAE{sub LB400}. Hence, BphAE{sub RR41} was able to metabolize 2,6,2 Prime ,6 Prime -, 3,4,3 Prime ,5 Prime - and 2,4,3 Prime ,4 Prime -tetrachlorobiphenyl that BphAE{sub LB400} is unable to metabolize. BphAE{sub RR41} was obtained by changing Thr335Phe336Asn338Ile341Leu409 of BphAE{sub LB400} to Ala335Met336Gln338Val341Phe409. Site-directed mutagenesis was used to create combinations of each substitution, in order to assess their individual contributions. Data show that the same Asn338Glu/Leu409Phe substitution that enhanced the ability to metabolize dibenzofuran resulted in a broadening of the PCB substrates range of the enzyme. The role of these substitutions on regiospecificities toward selected PCBs is also discussed.

  6. Ship-source pollution by polychlorinated biphenyls and brominated flame retardants

    OpenAIRE

    ČULIN, Jelena; Bielić, Toni

    2015-01-01

    Polychlorinated biphenyls (PCBs) and brominated flame retardants (BFRs) are groups of anthropogenic contaminants that have been routinely used in many applications for several decades. Prior to the discovery of their detrimental health effects and subsequent implementation of regulatory measures they were widely applied in shipbuilding. They are still found onboard active and inactive ships and pose a risk to human and environment. Therefore, it is important to continue to carry out preven...

  7. Effects of polychlorinated biphenyls on maternal odor conditioning in rat pups

    OpenAIRE

    Cromwell, Howard C.; Johnson, Asia; McKnight, Logan; Horinek, Maegan; Asbrock, Christina; Burt, Shannon; Jolous-Jamshidi, Banafsheh; Meserve, Lee A.

    2007-01-01

    Polychlorinated biphenyls (PCBs) are pervasive environmental contaminants that can have damaging effects on physiologic, motoric and cognitive function. Results from studies on PCBs and behavior have shown that exposure can alter learning and memory processes and that these shifts in cognitive abilities can be related to changes in hormonal and neural function. Little experimentation has been done on the impact of exposure to PCBs on social and emotional development. Previous work has shown t...

  8. Neurodevelopmental toxicity of prenatal polychlorinated biphenyls (PCBs) by chemical structure and activity: a birth cohort study

    OpenAIRE

    Park Hye-Youn; Hertz-Picciotto Irva; Sovcikova Eva; Kocan Anton; Drobna Beata; Trnovec Tomas

    2010-01-01

    Abstract Background Polychlorinated biphenyls (PCBs) are ubiquitous environmental toxins. Although there is growing evidence to support an association between PCBs and deficits of neurodevelopment, the specific mechanisms are not well understood. The potentially different roles of specific PCB groups defined by chemical structures or hormonal activities e.g., dioxin-like, non-dioxin like, or anti-estrogenic PCBs, remain unclear. Our objective was to examine the association between prenatal ex...

  9. Alteration of rat fetal cerebral cortex development after prenatal exposure to polychlorinated biphenyls

    OpenAIRE

    Naveau, Elise; Pinson, Anneline; GERARD, Arlette; Nguyen, Laurent; Charlier, Corinne; Thomé, Jean-Pierre; Zoeller, Robert Thomas; Bourguignon, Jean-Pierre; Parent, Anne-Simone

    2014-01-01

    Polychlorinated biphenyls (PCBs) are environmental contaminants that persist in environment and human tissues. Perinatal exposure to these endocrine disruptors causes cognitive deficits and learning disabilities in children. These effects may involve their ability to interfere with thyroid hormone (TH) action. We tested the hypothesis that developmental exposure to PCBs can concomitantly alter TH levels and TH-regulated events during cerebral cortex development: progenitor proliferation, cell...

  10. Polychlorinated Biphenyls and Leukocyte Telomere Length: An Analysis of NHANES 1999–2002

    OpenAIRE

    Franco Scinicariello; Buser, Melanie C.

    2015-01-01

    Polychlorinated biphenyls (PCBs) induce the expression of the proto-oncogene c-myc which has a role in cellular growth and proliferation programs. The c-myc up-regulates the telomerase reverse transcriptase which adds the telomeres repeating sequences to the chromosomal ends to compensate for the progressive loss of telomeric sequence. We performed multivariate linear regression to analyze the association of PCBs, polychlorinated dibenzo-p-dioxins, and 1,2,3,4,6,7,8-heptachlorodibenzofuran wi...

  11. Effects of Developmental Exposure to Polychlorinated Biphenyls and/or Polybrominated Diphenyl Ethers on Cochlear Function

    OpenAIRE

    Poon, Emily; Powers, Brian E.; McAlonan, Ruth M.; Ferguson, Duncan C.; Schantz, Susan L

    2011-01-01

    Developmental exposure to polychlorinated biphenyls (PCBs) causes hearing loss that may be due to reduced thyroxine during cochlear development. Polybrominated diphenyl ethers (PBDEs) are structurally similar to PCBs and reduce thyroxine. This study utilized an environmental PCB mixture and a commercial PBDE mixture, DE-71, that represents the PBDEs found in humans to assess the potential for additive effects of PCBs and PBDEs on cochlear function. Female Long-Evans rats were dosed with corn ...

  12. Tissue damage after acute intoxication by polychlorinated biphenyls (PCBs) in cockroaches Blattella germanica

    OpenAIRE

    Lambiase, S; Zhang, Y.; P. Morbini; M. Fasola

    2009-01-01

    It is common knowledge that polychlorinated biphenyls (PCBs) represent a serious threat to the health of both vertebrates and invertebrates. As far as the former are concerned, especially as regards human beings, a broad literature describes the direct and indirect effects induced by the PCBs on their systems and organs. Among invertebrates, the information available is mostly related to arthropods and is, however, very scarce. The aim of this work was to evaluate the effects of polychlorinat...

  13. A Preliminary Link between Hydroxylated Metabolites of Polychlorinated Biphenyls and Free Thyroxin in Humans

    OpenAIRE

    Eveline Dirinck; Dirtu, Alin C.; Govindan Malarvannan; Adrian Covaci; Jorens, Philippe G.; Van Gaal, Luc F.

    2016-01-01

    Background: Polychlorinated biphenyls (PCBs) and their hydroxylated metabolites (HO-PCBs) interfere with thyroid hormone action both in vitro and in vivo. However, epidemiologic studies on the link between PCB exposure and thyroid function have yielded discordant results, while very few data are available for HO-PCBs. Objectives: Our study aimed at investigating the relationship between clinically available markers of thyroid metabolism and serum levels of both PCBs and HO-PCBs. Subjects and ...

  14. Effects of Chinese domestic polychlorinated biphenyls (PCBs) on gonadal differentiation in Xenopus laevis.

    OpenAIRE

    Qin, Zhan-Fen; Zhou, Jing-Ming; Chu, Shao-Gang; Xu, Xiao-Bai

    2003-01-01

    To determine whether polychlorinated biphenyls (PCBs) influence gonadal differentiation in Xenopus laevis, tadpoles were exposed to two Chinese domestic PCBs (PCB3 and PCB5 from Nieuwkoop and Faber stage 46/47 to complete metamorphosis. Gonads were characterized using a dissecting microscope. The control X. laevis had normal ovaries or testes in gross morphology, whereas obviously abnormal testes including ovotestes were found in PCB3- and PCB5-exposed groups. Ovotestes were characterized by ...

  15. Biomonitoring and Elimination of Perfluorinated Compounds and Polychlorinated Biphenyls through Perspiration: Blood, Urine, and Sweat Study

    OpenAIRE

    Stephen J. Genuis; Sanjay Beesoon; Detlef Birkholz

    2013-01-01

    Perfluorinated compounds (PFCs) are man-made organofluorine chemicals manufactured and marketed for their stain-resistant properties. Polychlorinated biphenyls (PCBs) are anthropogenic organochlorine compounds previously used in various industrial and chemical applications prior to being banned in the Western world in the 1970s. Both PFCs and PCBs are persistent contaminants within the human organism and both have been linked to adverse health sequelae. Data is lacking on effective means to f...

  16. Polychlorinated biphenyls fractioning assessment in aqueous bioremediation assy with phanerochaete chrysosporium

    OpenAIRE

    Sangely, Matthieu; Sablayrolles, Caroline; Vialle, Claire; Strehaiano, Pierre; Thannberger, Laurent; Vignoles, Mireille

    2009-01-01

    Thanks to growing environmental concerns in public opinion, bioremediation processes are more and more used to decontaminate soils from organic compounds. Polychlorinated biphenyls (PCBs) are known to be world wide spread persistent organic pollutants (POPs). The white rot fungus Phanerochaete chrysosporium is able to degrade PCBs in water, and soil As POPs, PCBs can also be adsorbed onto organic matter, such as Phanerochaete chrysosporium mycelium. This study aims at estimating the fractioni...

  17. Oculodermatological findings in workers with occupational exposure to polychlorinated biphenyls (PCBs).

    OpenAIRE

    Fischbein, A; Rizzo, J N; Solomon, S J; Wolff, M S

    1985-01-01

    Oculodermatological findings, such as hypersecretion of the Meibomian glands, swelling of the upper eyelids and hyperpigmentation of the conjunctivae are considered typical of "PCB poisoning." They were common clinical manifestations of yusho and yu-cheng, two epidemics in Japan and Taiwan caused by the ingestion of rice cooking oil contaminated with polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans. To investigate the prevalence of such abnormalities in a population with lon...

  18. Prenatal and postnatal exposure to polychlorinated biphenyls and child size at 24 months of age

    OpenAIRE

    Jackson, Leila W.; Lynch, Courtney D.; Kostyniak, Paul J.; McGuinness, Bridget M; Buck Louis, Germaine M.

    2009-01-01

    Research suggests that exposure to polychlorinated biphenyls (PCBs) may result in decreased child growth, though the critical window(s) are unclear. We investigated the association between PCBs and child size at age 24 months (n=44). PCBs were measured in 1st trimester serum, breast milk, and child serum at age 24 months, and dichotomized at the median. Age- and gender-specific z-scores were calculated for anthropometric measures. Using linear regression, we observed no significant changes in...

  19. Perinatal exposure to polychlorinated biphenyls and dioxins and its effect on neonatal neurological development

    OpenAIRE

    Huisman, Martijn; Koopman-Esseboom, Corine; Fidler, Vaclav; Hadders-Algra, Mijna; Paauw, Cornelis; Tuinstra, L.G.M.Th.; Weisglas-Kuperus, Nynke; Sauer, Pieter; Touwen, Bert C.; Boersma, Eric

    1995-01-01

    textabstractPolychlorinated biphenyls (PCBs) and dioxins (polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs)) are widespread environmental contaminants which are neurotoxic in animals. Perinatal exposure to PCBs, PCDDs, and PCDFs occurs prenatally via the placenta and postnatally via breast milk. To investigate whether such an exposure affects the neonatal neurological condition, the neurological optimality of 418 Dutch newborns was evaluated with the Prechtl neurological ex...

  20. Evaluating Health Risks from Inhaled Polychlorinated Biphenyls: Research Needs for Addressing Uncertainty

    OpenAIRE

    Lehmann, Geniece M.; Christensen, Krista; Maddaloni, Mark; Phillips, Linda J.

    2014-01-01

    Background: Indoor air concentrations of polychlorinated biphenyls (PCBs) in some buildings are one or more orders of magnitude higher than background levels. In response to this, efforts have been made to assess the potential health risk posed by inhaled PCBs. These efforts are hindered by uncertainties related to the characterization and assessment of source, exposure, and exposure-response. Objectives: We briefly describe some common sources of PCBs in indoor air and estimate the contribut...

  1. Rhizospere Redox Cycling and Implications for Rhizosphere Biotransformation of Selected Polychlorinated Biphenyl (PCB) Congeners

    OpenAIRE

    Meggo, Richard E.; Schnoor, Jerald L.

    2013-01-01

    Theoretically, sequential cycles of dechlorination followed by aerobic bio-oxidation are desirable to achieve complete degradation of a mixture of higher and lower chlorinated PCBs. In this research, soil was artificially contaminated with polychlorinated biphenyls (PCBs) in mixture and as single congeners, aged, and planted with two different plant species. Alternating redox cycles were created in the root zone of plants by flooding and draining the soil. Over 32 weeks, switchgrass (Panicum ...

  2. Polychlorinated biphenyls-induced alterations of thyroid hormone homeostasis and brain development in the rat.

    OpenAIRE

    Morse, D.C.

    1995-01-01

    IntroductionThe work described in this thesis was undertaken to gain insight in the processes involved in the developmental neurotoxicity of polychlorinated biphenyls. It has been previously hypothesized that the alteration of thyroid hormone status by PCBs may be in part responsible for the developmental neurotoxicity of these compounds in humans (Rogan et al. 1986). This is a logical hypothesis, given the well-described effects of PCBs on plasma thyroid hormone levels in adult animals, and ...

  3. CONTAMINATION OF POLYCHLORINATED BIPHENYLS IN FISHES LEADING TO TOXICITY IN FISH CONSUMING POPULATION

    OpenAIRE

    Govind Pandey; Madhuri S.; A.B. Shrivastav

    2012-01-01

    The pollution of rivers and streams with chemical contaminants has become one of the most critical environmental problems. Similar to humans and other species of animals, fish have also been found to be polluted with a large number of pollutants/contaminants. Unintentionally added chemicals causing fish toxicity include organochlorine pesticides, polychlorinated biphenyls (PCBs) and other persistent chemicals in feed, chemicals in construction materials, and metabolites and degradation produc...

  4. Two anaerobic polychlorinated biphenyl-dehalogenating enrichments that exhibit different para-dechlorination specificities.

    OpenAIRE

    Wu, Q; Wiegel, J

    1997-01-01

    Two anaerobic polychlorinated biphenyl (PCB)-dechlorinating enrichments with distinct substrate specificities were obtained: a 2,3,4,6-tetrachlorobiphenyl (2346-CB) para-dechlorinating enrichment derived from Aroclor 1260-contaminated Woods Pond (Lenox, Mass.) sediment and a 2,4,6-trichlorobiphenyl (246-CB) unflanked para-dechlorinating enrichment derived from PCB-free Sandy Creek Nature Center (Athens, Ga.) sediment. The enrichments have been successfully transferred to autoclaved soil slurr...

  5. Potential for Polychlorinated Biphenyl Biodegradation in Sediments from Indiana Harbor and Ship Canal

    OpenAIRE

    Liang, Yi; Martinez, Andres; Hornbuckle, Keri C.; Mattes, Timothy E.

    2014-01-01

    Polychlorinated biphenyls (PCBs) are carcinogenic, persistent, and bioaccumulative contaminants that pose risks to human and environmental health. In this study, we evaluated the PCB biodegradation of sediments from Indiana Harbor and Ship Canal (IHSC), a PCB-contaminated site (average PCB concentration = 12,570 ng/g d.w.). PCB congener profiles and bacterial community structure in a core sediment sample (4.57 m long) were characterized. Analysis of vertical PCB congener profile patterns in s...

  6. Polychlorinated biphenyls in the surficial sediment of Indiana Harbor and Ship Canal, Lake Michigan

    OpenAIRE

    Martinez, Andres; Norström, Karin; Wang, Kai; Hornbuckle, Keri C.

    2009-01-01

    We report the results of the first intensive survey of polychlorinated biphenyls (PCBs) in the surficial sediment of the Indiana Harbor and Ship Canal (IHSC) in East Chicago, Indiana, a part of the Calumet River tributary of Lake Michigan that will be dredged to maintain depth for ship traffic. The tributary has previously been reported to be a large source of PCBs to Lake Michigan. PCB congeners were measured using tandem mass spectrometry in multiple reaction monitoring mode, a method that ...

  7. (Biphenyl-2-yl)bromidobis(2-methyl-tetra-hydro-furan-κO)magnesium(II).

    Science.gov (United States)

    Nordschild, Simon; Wohlgemuth, D; Bolte, Michael

    2009-01-01

    In the title Grignard reagent, [MgBr(C(12)H(9))(C(5)H(10)O)(2)], the Mg centre adopts a distorted tetra-hedral MgCO(2)Br arrangement. The dihedral angle between the two aromatic rings of the biphenyl residue is 44.00 (14)°. Each mol-ecule incorporates one R- and one S-configured 2-methyl-tetra-hydro-furan mol-ecule. PMID:21583743

  8. Plant compounds that induce polychlorinated biphenyl biodegradation by Arthrobacter sp. strain B1B.

    OpenAIRE

    Gilbert, E S; Crowley, D. E.

    1997-01-01

    Plant compounds that induced Arthrobacter sp. strain B1B to cometabolize polychlorinated biphenyls (PCBs) were identified by a screening assay based on the formation of a 4,4'-dichlorobiphenyl ring fission product. A chemical component of spearmint (Mentha spicata), l-carvone, induced Arthrobacter sp. strain B1B to cometabolize Aroclor 1242, resulting in significant degradation of 26 peaks in the mixture, including selected tetra- and pentachlorobiphenyls. Evidence for PCB biodegradation incl...

  9. Relationships of Polychlorinated Biphenyls and Dichlorodiphenyldichloroethylene (p,p’-DDE) with Testosterone Levels in Adolescent Males

    OpenAIRE

    Schell, Lawrence M.; Gallo, Mia V.; Deane, Glenn D.; Nelder, Kyrie R.; DeCaprio, Anthony P; Jacobs, Agnes; ,

    2013-01-01

    Background: Concern persists over endocrine-disrupting effects of persistent organic pollutants (POPs) on human growth and sexual maturation. Potential effects of toxicant exposures on testosterone levels during puberty are not well characterized. Objectives: In this study we evaluated the relationship between toxicants [polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p´-DDE), hexachlorobenzene (HCB), and lead] and testosterone levels among 127 Akwesasne Mohawk males 10 ...

  10. Polychlorinated biphenyls in serum of the Siberian Yupik people from St. Lawrence Island, Alaska

    OpenAIRE

    Carpenter, David O.; DeCaprio, Anthony P; O’Hehir, David; Akhtar, Farooq; Johnson, Glenn.; Scrudato, Ronald J.; Apatiki, Lucy; Kava, Jane; Gologergen, Jesse; Miller, Pamela K.; Eckstein, Lorraine

    2005-01-01

    Objectives. To determine serum levels of polychlorinated biphenyls (PCBs) in Siberian Yupik adults from St. Lawrence Island, Alaska, and to determine the relative contribution of atmospheric transport of PCBs and local contamination to body burdens. Study Design. Siberian Yupiks of various ages were recruited from three populations: residents of the village of Gambell, residents of the village of Savoonga who did not have family hunting camps near the Northeast Cape (NEC), a Formerly Used Def...

  11. Metabolomic Analysis of the Effects of Polychlorinated Biphenyls in Non-alcoholic Fatty Liver Disease

    OpenAIRE

    Shi, Xue; Wahlang, Banrida; Wei, Xiaoli; Yin, Xinmin; Falkner, K. Cameron; Prough, Russell A.; Kim, Seong Ho; Mueller, Eugene G.; McClain, Craig J.; Cave, Matthew; Zhang, Xiang

    2012-01-01

    Polychlorinated Biphenyls (PCBs) are persistent organic pollutants and have been associated with abnormal liver enzymes and suspected non-alcoholic fatty liver disease (NAFLD), obesity, and the metabolic syndrome in epidemiological studies. In epidemiological surveys of human PCB exposure, PCB 153 has the highest serum levels among PCB congeners. To determine the hepatic effects of PCB 153 in mice, C57BL/6J mice were fed either a control diet (CD) or a high fat diet (HFD) for 12 weeks, with o...

  12. Effects of polychlorinated biphenyls and environmental biotransformation products on aquatic nitrification.

    OpenAIRE

    Sayler, G S; Shiaris, M. P.; Beck, W.; Held, S.

    1982-01-01

    The effects of polychlorinated biphenyls (PCBs) on nitrification were examined for pure cultures and natural reservoir samples. PCBs at concentrations greater than 10 microgram liter-1 inhibited nitrification, principally ammonium oxidation, in one of two natural reservoir environments. However, this inhibition could not be reproduced in pure high-cell-density cultures or in previously contaminated reservoir waters. A PCB environmental biotransformation product, p-chlorophenylglyoxylic acid, ...

  13. Chlororganische Pestizide, polychlorierte Biphenyle und potentiell toxische Schwermetalle in Organproben von Seeadlern und Habichten

    OpenAIRE

    Kenntner, Norbert

    2010-01-01

    In the present study, we examined organs of 145 white-tailed eagles (Haliaeetus albicilla) from Germany and 5 specimen from Austria, as well as 62 northern goshawks (Accipiter gentilis) from different regions of Germany for their organ concentrations of chlorinated pesticides, polychlorinated biphenyls (PCB) and potentially toxic heavy metals. We proved a significant decline of DDT concentrations in livers of 127 white-tailed eagles (WTE) collected between 1990 and 2001. Considering the final...

  14. Field-derived Henry's law constants for polychlorinated biphenyls in oceanic waters

    OpenAIRE

    Gioia, Rosalinda; Dachs, Jordi; Lohmann, Rainer; Jones, Kevin C.; Nizzeto, Luca

    2010-01-01

    Accurate knowledge of Henry's law constants (Kaw) is very important for fate and transport studies of organic chemicals. Here field-derived Kaw values for polychlorinated biphenyl (PCB) congeners (PCBs 28, 49, 52, 118, 138, 149, and 153) were determined in the open Atlantic Ocean, at locations where air and seawater were assumed to be at equilibrium. Field-based Kaw values were derived from air and seawater samples simultaneously collected at these locations, and their relationship with tempe...

  15. Immunologic effects of background exposure to polychlorinated biphenyls and dioxins in Dutch preschool children.

    OpenAIRE

    Weisglas-Kuperus, Nynke; Patandin, Svati; Berbers, G A; Sas, Theo; Sauer, Pieter; Hooijkaas, Herbert; Mulder, Paul

    2000-01-01

    textabstractPrenatal exposure to polychlorinated biphenyls (PCBs) and dioxins is associated with changes in the T-cell lymphocyte population in healthy Dutch infants. We investigated whether these changes persist into later childhood and whether background exposure to PCBs and dioxins is associated with the prevalence of infectious or allergic diseases and humoral immunity at preschool age. The total study group consisted of 207 healthy mother-infant pairs. We estimated prenatal exposure to P...

  16. CLOSURE REPORT FOR CORRECTIVE ACTION UNIT 528: POLYCHLORINATED BIPHENYLS CONTAMINATION NEVADA TEST SITE, NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    BECHTEL NEVADA

    2006-09-01

    This Closure Report (CR) describes the closure activities performed at CAU 528, Polychlorinated Biphenyls Contamination, as presented in the Nevada Division of Environmental Protection (NDEP)-approved Corrective Action Plan (CAP) (US. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSAINSO], 2005). The approved closure alternative was closure in place with administrative controls. This CR provides a summary of the completed closure activities, documentation of waste disposal, and analytical data to confirm that the remediation goals were met.

  17. Cometabolic oxidation of polychlorinated biphenyls in soil with a surfactant-based field application vector.

    OpenAIRE

    Lajoie, C. A.; Layton, A C; Sayler, G. S.

    1994-01-01

    Polychlorinated biphenyl (PCB)-degradative genes, under the control of a constitutive promoter, were cloned into a broad-host-range plasmid and a transposon. These constructs were inserted into a surfactant-utilizing strain, Pseudomonas putida IPL5, to create a field application vector (FAV) in which a surfactant-degrading organism cometabolizes PCB. By utilizing a surfactant not readily available to indigenous populations and a constitutive promoter, selective growth and PCB-degradative gene...

  18. Polychlorinated biphenyls in eggs and chlorioallantoic membranes of American alligators (Alligator mississippiensis) from coastal South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, G.P.; Wood, P.D. [Clemson Univ., Pendleton, SC (United States); O`Quinn, M. [South Carolina Governor`s School for Science and Mathematics, Hartsville, SC (United States)

    1997-07-01

    Assessing chemical exposure in threatened or endangered wildlife species presents unique analytical problems. Chorioallantoic membranes (CAMs) have been proposed as surrogate tissues for evaluation of polychlorinated biphenyl (PCB) exposure in oviparous species. Research was undertaken to determine the extent of PCB accumulation in alligators (Alligator mississippiensis) at sites along the coast of South Carolina and to evaluate the utility of CAMs as surrogate tissues for determining PCB concentrations in whole alligator eggs. Polychlorinated biphenyls were found in eggs and CAMs of alligators from both sites examined. Concentrations of PCBs were higher in CAMs (p = 0.02) and eggs (p = 0.001) from sites known to contain chlorinated hydrocarbons than from more pristine sites. Total PCBs partitioned predictably (r{sup 2} > 0.59; p < 0.02) between egg and CAM tissues indicating the utility of CAMs to serve as surrogate tissues when comparing total PCB concentrations in whole eggs. Tetrachloro through octachloro biphenyl homologues and total PCBs in CAMs from reference areas were correlated with concentrations of these homologues in eggs. At contaminated sites, total PCB concentrations in CAMs were correlated with total PCB concentrations in eggs.

  19. Interconversion between Methoxylated and Hydroxylated Polychlorinated Biphenyls in Rice Plants: An Important but Overlooked Metabolic Pathway.

    Science.gov (United States)

    Sun, Jianteng; Pan, Lili; Su, Zhenzhu; Zhan, Yu; Zhu, Lizhong

    2016-04-01

    To date, there is limited knowledge on the methoxylation of polychlorinated biphenyls (PCBs) and the relationship between hydroxylated polychlorinated biphenyls (OH-PCBs) and methoxylated polychlorinated biphenyls (MeO-PCBs) in organisms. In this study, rice (Oryza sativa L.) was chosen as the model organism to determine the metabolism of PCBs in plants. Limited para-substituted 4'-OH-CB-61 (major metabolite) and 4'-MeO-CB-61 (minor metabolite) were found after a 5-day exposure to CB-61, while ortho- and meta-substituted products were not detected. Interconversion between OH-PCBs and MeO-PCBs in organisms was observed for the first time. The demethylation ratio of 4'-MeO-CB-61 was 18 times higher than the methylation ratio of 4'-OH-CB-61, indicating that formation of OH-PCBs was easier than formation of MeO-PCBs. The transformation products were generated in the roots after 24 h of exposure. The results of in vivo and in vitro exposure studies show that the rice itself played a key role in the whole transformation processes, while endophytes were jointly responsible for hydroxylation of PCBs and demethylation of MeO-PCBs. Metabolic pathways of PCBs, OH-PCBs, and MeO-PCBs in intact rice plants are proposed. The findings are important in understanding the fate of PCBs and the source of OH-PCBs in the environment. PMID:26928534

  20. Accelerated delivery of polychlorinated biphenyls (PCBs) in recent sediments near a large seabird colony in Arctic Canada

    International Nuclear Information System (INIS)

    Polychlorinated biphenyls (PCBs) were measured in sediment cores from ponds located near a large seabird colony at Cape Vera, Devon Island, Arctic Canada. Surface sediment PCB concentrations were ∼5x greater in seabird-affected sites relative to a nearby control pond and were correlated with independent indicators of seabird activity including, sedimentary δ15N and lakewater chlorophyll a and cadmium concentrations. PCB fluxes were amongst the highest recorded from the High Arctic, ranging from 290 to 2400 ng m-2 yr-1. Despite a widespread ban of PCBs in the mid-1970s, PCB accumulation rates in our cores increased, with the highest values recorded in the most recent sediments. Possible mechanisms for the recent PCB increases include a vertical flux step driven by seabird-delivered nutrients and/or delayed loading of PCBs from the catchment into the ponds. The high PCB levels recorded in the seabird-affected sites suggest that seabird colonies are exposing coastal ecosystems to elevated levels of contaminants. - Seabird activity accelerates the delivery of PCBs from marine to terrestrial ecosystems.

  1. A Temperate Alpine Glacier as a Reservoir of Polychlorinated Biphenyls: Model Results of Incorporation, Transport, and Release.

    Science.gov (United States)

    Steinlin, Christine; Bogdal, Christian; Lüthi, Martin P; Pavlova, Pavlina A; Schwikowski, Margit; Zennegg, Markus; Schmid, Peter; Scheringer, Martin; Hungerbühler, Konrad

    2016-06-01

    In previous studies, the incorporation of polychlorinated biphenyls (PCBs) has been quantified in the accumulation areas of Alpine glaciers. Here, we introduce a model framework that quantifies mass fluxes of PCBs in glaciers and apply it to the Silvretta glacier (Switzerland). The models include PCB incorporation into the entire surface of the glacier, downhill transport with the flow of the glacier ice, and chemical fate in the glacial lake. The models are run for the years 1900-2100 and validated by comparing modeled and measured PCB concentrations in an ice core, a lake sediment core, and the glacial streamwater. The incorporation and release fluxes, as well as the storage of PCBs in the glacier increase until the 1980s and decrease thereafter. After a temporary increase in the 2000s, the future PCB release and the PCB concentrations in the glacial stream are estimated to be small but persistent throughout the 21st century. This study quantifies all relevant PCB fluxes in and from a temperate Alpine glacier over two centuries, and concludes that Alpine glaciers are a small secondary source of PCBs, but that the aftermath of environmental pollution by persistent and toxic chemicals can endure for decades. PMID:27164482

  2. Mast cells in the intestine and gills of the sea bream, Sparus aurata, exposed to a polychlorinated biphenyl, PCB 126.

    Science.gov (United States)

    Lauriano, Eugenia Rita; Calò, Margherita; Silvestri, Giuseppa; Zaccone, Daniele; Pergolizzi, Simona; Lo Cascio, Patrizia

    2012-02-01

    The presence of mast cells has been reported in all classes of vertebrates, including many teleost fish families. The mast cells of teleosts, both morphologically and functionally, show a close similarity to the mast cells of mammals. Mast cells of teleosts, localized in the vicinity of blood vessels of the intestine, gills and skin, may play an important role in the mechanisms of inflammatory response, because they express a number of functional proteins, including piscidins, which are antimicrobical peptides that act against a broad-spectrum of pathogens. An increase in the number of mast cells in various tissues and organs of teleosts seems to be linked to a wide range of stressful conditions, such as exposure to heavy metals (cadmium, copper, lead and mercury), exposure to herbicides and parasitic infections. This study analyzed the morphological localization and abundance of mast cells in the intestine and gills of sea bream, Sparus aurata, after a 12, 24 or 72 h exposure to PCB 126, a polychlorinated biphenyl, which is a potent immunotoxic agent. In the organs of fish exposed to PCB 126, it was observed that in addition to congestion of blood vessels, there was extravasation of red blood cells, infiltration of lymphocytes, and a progressive increase in numbers of mast cells. These data confirm the immunotoxic action of PCB, and the involvement of mast cells in the inflammatory response. PMID:21565388

  3. Trophic magnification of polychlorinated biphenyls and polybrominated diphenyl ethers in an estuarine food web of the Ariake Sea, Japan.

    Science.gov (United States)

    Kobayashi, Jun; Imuta, Yuki; Komorita, Tomohiro; Yamada, Katsumasa; Ishibashi, Hiroshi; Ishihara, Fumitaka; Nakashima, Naoya; Sakai, Jun; Arizono, Koji; Koga, Minoru

    2015-01-01

    To evaluate trophic biomagnification of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in an estuary of the Ariake Sea, Japan, we measured concentrations of 209 PCB congeners and 28 PBDE congeners, and nitrogen stable isotope (δ(15)N) levels in living aquatic organisms. The trophic magnification factor (TMF) for ΣPCBs (all 209 congeners) was 1.52, and TMFs for 58 PCB congeners ranged from 0.90 to 3.28. In contrast, TMF for ΣPBDEs was 1.17, and TMFs for 7 PBDE congeners ranged from 0.46 to 1.66. TMFs of PCB and PBDE congeners in this study were lower than those in marine food webs, and were similar to those in a lake food web. However, although negative relationships were observed between TMF and log octanol-water partition coefficient (KOW) values among PCB congeners in this study (log KOW up to 7), positive relationships have been reported in several other studies. In the present estuary, PCB concentrations in sea bass may not reach a steady state because sea bass are migratory species. Therefore, TMFs of highly chlorinated congeners with high log KOW values take longer to reach the steady state and may not increase with increasing log KOW. PMID:25240773

  4. Accelerated delivery of polychlorinated biphenyls (PCBs) in recent sediments near a large seabird colony in Arctic Canada

    Energy Technology Data Exchange (ETDEWEB)

    Michelutti, Neal, E-mail: nm37@queensu.c [Paleoecological Environmental Assessment and Research Laboratory (PEARL), Department of Biology, Queen' s University, 116 Barrie St., Kingston, ON K7L 3N6 (Canada); Liu, Huijun [Department of Environmental Science, Zhejiang Gongshang University, Hangzhou (China); Smol, John P. [Paleoecological Environmental Assessment and Research Laboratory (PEARL), Department of Biology, Queen' s University, 116 Barrie St., Kingston, ON K7L 3N6 (Canada); Kimpe, Lynda E. [Program for Chemical and Environmental Toxicology, Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5 (Canada); Keatley, Bronwyn E. [Paleoecological Environmental Assessment and Research Laboratory (PEARL), Department of Biology, Queen' s University, 116 Barrie St., Kingston, ON K7L 3N6 (Canada); Mallory, Mark [Environment Canada, Iqaluit, NU (Canada); Macdonald, Robie W. [Department of Fisheries and Oceans, Sidney, BC V8L 4B2 (Canada); Douglas, Marianne S.V. [University of Alberta, Edmonton, AB T6G 2E3 (Canada); Blais, Jules M. [Program for Chemical and Environmental Toxicology, Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5 (Canada)

    2009-10-15

    Polychlorinated biphenyls (PCBs) were measured in sediment cores from ponds located near a large seabird colony at Cape Vera, Devon Island, Arctic Canada. Surface sediment PCB concentrations were approx5x greater in seabird-affected sites relative to a nearby control pond and were correlated with independent indicators of seabird activity including, sedimentary delta{sup 15}N and lakewater chlorophyll a and cadmium concentrations. PCB fluxes were amongst the highest recorded from the High Arctic, ranging from 290 to 2400 ng m{sup -2} yr{sup -1}. Despite a widespread ban of PCBs in the mid-1970s, PCB accumulation rates in our cores increased, with the highest values recorded in the most recent sediments. Possible mechanisms for the recent PCB increases include a vertical flux step driven by seabird-delivered nutrients and/or delayed loading of PCBs from the catchment into the ponds. The high PCB levels recorded in the seabird-affected sites suggest that seabird colonies are exposing coastal ecosystems to elevated levels of contaminants. - Seabird activity accelerates the delivery of PCBs from marine to terrestrial ecosystems.

  5. Advances in reactive surfactants.

    Science.gov (United States)

    Guyot, A

    2004-05-20

    The study of reactive surfactants and their applications in the synthesis of latexes for waterborne coatings has been recently boosted by two successive European programmes, involving all together eight academic and five industrial laboratories. The most significant results were obtained using surfactants derived from maleic and related anhydrides, or both nonionic and anionic reactive polymeric surfactants. Such surfactants are able to improve the stability of styrenic and acrylic latexes vs. various constraints, such as electrolyte addition, freeze-thawing tests or extraction with alcohol or acetone. The properties of films used in waterborne coatings are also improved in case of water exposure (less water uptake, dimensional stability), as well as improved weatherability, and blocking properties. Formulations for woodstain varnishes, metal coating of printing inks, based on the use of simple polymerizable surfactants, are now in the market. PMID:15072924

  6. Alkylidynephosphines : syntheses and reactivity

    OpenAIRE

    Becker, Gerd; Becker, Winfried; Knebl, Robert; Schmidt, Helmut; Hildenbrand, Ute; Westerhausen, Matthias

    1987-01-01

    In the past, different methods have been utilized for the preparation of alkylidynephosphines. Whereas, however, small amounts of thermally instable derivatives might be obtained from reactions in the gas phase, the synthesis of phosphines which are stable under an inert atmosphere, as for instance those with a tert-butyl or a 1-adamantyl substituent at the carbon atom of the PEC group, is best started with tris (trimethylsilyl) phosphine itself or with the more reactive lithium bis (trimethy...

  7. Reactive Turing Machines

    OpenAIRE

    Baeten, J.C.M.; Luttik, B.; Tilburg, van, T.G.

    2011-01-01

    We propose reactive Turing machines (RTMs), extending classical Turing machines with a process-theoretical notion of interaction, and use it to define a notion of executable transition system. We show that every computable transition system with a bounded branching degree is simulated modulo divergence-preserving branching bisimilarity by an RTM, and that every effective transition system is simulated modulo the variant of branching bisimilarity that does not require divergence preservation. ...

  8. Reactivity of nitrosyl group

    International Nuclear Information System (INIS)

    Reactivity of ruthenium nitrosyl complexes is considered. According to X-ray structure analysis data nitrogen oxide interaction with metals results in formation of two complexes. The first ones contain linear nitrosyls (valence bond angle 180 deg in M-NO grouping), the second ones - bend nitrosyls (the bond angle in M-N-O grouping 120-130 deg). The first type complexes react primarily with nucleophilic reagents (OH-, N3-), the second ones - with electrophilic reagents

  9. Organochlorine pesticides and polychlorinated biphenyls in the Arctic Ocean food web.

    Science.gov (United States)

    Hargrave, B T; Harding, G C; Vass, W P; Erickson, P E; Fowler, B R; Scott, V

    1992-01-01

    Polychlorinated biphenyls (PCBs), polychlorinated camphenes (PCCs) and isomers of DDT and DDE were the predominant organochlorine (OC) hydrocarbons measured in epontic particulate matter, zooplankton, pelagic and benthic amphipods and liver tissue from an abyssal fish collected in the Arctic Ocean. Chlordane, dieldrin and other cyclodienes and hexachlorocyclohexane (HCH) isomers were present at lower concentrations. Levels on a dry weight basis in plankton of various sizes less than 63 microns to 2 mm were similar to those in epontic particulate matter, but on a lipid weight basis, concentrations in smaller plankton were two to five times higher. Organochlorines in amphipods and liver from the glacial eelpout Lycodes frigidus exceeded levels in zooplankton by up to an order of magnitude. Large benthic lysianassid amphipods (Tmetonyx cicada, Anonyx nugax and Eurythenes gryllus) accumulated higher concentrations on a dry and lipid weight basis than small species (Onisimus spp. and Andaniexis spp.) or the under-ice gammaridean amphipod (Gammarus wilkitzkii). No significant differences in OC levels were measured in benthic amphipods collected at different times. However, concentrations in large zooplankton (greater than 500 microns) collected in August, dominated by adult copepods and ctenophores, contained concentrations of alpha-HCH, chlordane isomers and other cyclodienes that were two to four times higher than levels in May. Ratios of alpha-HCH: gamma-HCH (5 to 10) were similar to those in seawater collected simultaneously but there was no difference in ratios in various size categories of planktonic and benthic crustaceans indicating no selective accumulation or metabolic alteration of these isomers. Ratios of cis-chlordane:trans-chlordane concentrations were lower in all sizes of zooplankton (2 to 3) than in shelf amphipods (3 to 6) which corresponded to an increase in the ratio with depth. Higher ratios of DDT:DDE in plankton (2 to 6) than in amphipods (1 to 2

  10. Sexual difference in gonadal development of embryonic chickens after treatment of polychlorinated biphenyls

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Polychlorinated biphenyls (PCBs) are ubiquitous, persistent and lipophilic environmental endocrine disrupters that can be biomagnified in human and animals including birds and thus to affect reproductive functions.Poultry meat and eggs contain a great deal of fat and possibly concentrate higher PCBs and other environmental contaminants such as dichlorodiphenyl-trichloroethane (DDT).In order to identify the adverse effects of PCBs and possible sexual difference on chicken gonadal development, Aroclor 1254 was injected into fertilized Hyline chicken eggs before incubation. Four groups of eggs received yolk injection of either peanut oil as control, 1, 10 or 100 μg/egg of Aroclor 1254 as treatment group, respectively. After hatching the gonads were removed for histological examination. Testicular structure was apparently changed and exhibited dramatic decrease in area of the transverse sections (1 μg/egg, P< 0.01; 10 and 100 μg/egg, P<0.001), diameter (10 and 100 μg/egg, P <0.05) and relative area of the testicular tubules (10 μg/egg, P<0.05; 100 μg/egg, P<0.01). Most testicular tubules of the highest dose group degenerated and even disappeared. The differentiation of germ cells was retarded in all groups treated with Aroclor 1254. Some germ cells were irregular in shape, with vacuolated cytoplasm and hyperchromatism nucleus (pyknosis) in 1 and 10 μg/egg groups and almost all germ cells in 100 μg/egg group. In contrast,the area of the left ovarian transverse sections increased dramatically (10 and 100 lμg/egg, P <0.001), the ovarian cortex manifested a significant increment in thickness (1, 10 and 100 μg/egg, P <0.001) and a higher number of oocytes was observed (1, 10 and 100 μg/egg, P <0.001) in the female chickens treated with Aroclor 1254 compared with the control group. A few oocytes with vacuolated cytoplasm and hyperchromatic nucleus were also observed in ovarian cortex after PCBs exposure. These results showed that PCBs interfered

  11. Diabetes in Native Americans: elevated risk as a result of exposure to polychlorinated biphenyls (PCBs).

    Science.gov (United States)

    Aminov, Zafar; Haase, Richard; Carpenter, David O

    2016-03-01

    We have studied rates of diabetes in 601 members of the Mohawk Nation at Akwesasne, ages 18-84 years, in relation to serum concentrations of 101 polychlorinated biphenyl (PCB) congeners and three chlorinated pesticides [dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and mirex]. Diabetes was determined from either a diagnosis by a physician or by having a fasting glucose concentration of >125 mg/dL. Rates of diabetes are high in this community. Three models were used. In the first model rate ratios (RR) were determined for quartiles of total PCBs after adjustment for age, sex, body mass index (BMI) and total serum lipids. For total PCBs RR=2.21 (1.2-4.2), while for total pesticides RR=3.75 (1.3-10.7). When the total PCB results were also adjusted for total pesticides and the total pesticide results were also adjusted for total PCBs (Model 2) the RRs were somewhat reduced. In Model 3 we considered subgroups of PCBs based on numbers of chlorines on the molecule (tri-/tetra, penta-/hexa, hepta plus) and numbers of ortho chlorines (non-/mono; di-, tri-/tetra-), and considered each of the pesticides individually after adjustment for all other contaminants as well as age, sex, BMI and serum lipids. We found a highly significant association between diabetes and PCBs with only three or four chlorines (RR=5.02), but no significant association with those with greater chlorination. When evaluating PCBs based on numbers of ortho chlorines only, those with no or one ortho chlorine showed significant associations. As mono-ortho PCBs include some with dioxin-like activity, we compared those with and without a TEF, and found that the association with diabetes was exclusively with the non-dioxin-like congeners. Of the pesticides only hexachlorobenzene showed a small but significant association with diabetes. Because lower chlorinated PCBs are more volatile and do not greatly accumulate in fish, these results suggest that inhalation is the major route of exposure to

  12. Radiological tracing for historical patterns of polychlorinated biphenyls in creek ecosystem

    International Nuclear Information System (INIS)

    The marine sediments act like sink for most of the pollutants entering the aquatic environment. It becomes more critical in the case of creek ecosystem due to its landlocked and relatively stagnant nature. Various persistent organic pollutants (POPs) like polychlorinated biphenyls (PCBs) are brought into the creek in the form of dissolved and particulate fluxes from industrial effluents, sewerage discharge, urban runoff from the city, spillage, disposal and chemical weathering. PCBs cycle between sediment, water, air and soil. Studying the historical patterns of these toxic pollutants depositions in sediment cores have several applications. They throw light on the chronological inputs of the pollutants in the marine body. Natural radionuclides like 210Pb act as tracers for determining the historical patterns of these pollutants in different sediment layers. Determining the activities of these radionuclides is useful for determining the age of sediment layers from the sedimentation rates. The unsupported 210Pb activity of the Thane creek sediments was determined and modeled for assigning the age to different layers of the cores contaminated with PCBs. The unsupported activity of 210Pb tracer was found to decrease with the increase in depth of the sediment layers. This pattern of the 210Pb activity was used for determining the sedimentation rate and age of the core layers. The CRS model with 210Pb activity traced the average sedimentation rate in Thane Creek to 0.67 cm/yr. This helped in labeling the age of formation of the deep core sediment layers. The vertical profile of different PCB congener concentrations in the core samples depicts a gradient from top to bottom, which indicates the influence of industrial contributions over the period. Peak concentrations for the congeners were observed at 13-24 depth, which indicates excessive loading of sediment with these compounds during 1970s (20-30 cm) which was the period of the maximum use and production of these

  13. Reactive modification of polyesters and their blends

    Science.gov (United States)

    Wan, Chen

    2004-12-01

    As part of a broader research effort to investigate the chemical modification of polyesters by reactive processing a low molecular weight (MW) unsaturated polyester (UP) and a higher MW saturated polyester, polyethylene terephthalate (PET), alone or blended with polypropylene (PP) were melt processed in a batch mixer and continuous twin screw extruders. Modification was monitored by on-line rheology and the products were characterized primarily by off-line rheology, morphology and thermal analysis. Efforts were made to establish processing/property relationships and provide an insight of the accompanying structural changes. The overall response of the reactively modified systems was found to be strongly dependent on the component characteristics, blend composition, type and concentrations of reactive additives and processing conditions. The work concluded that UP can be effectively modified through reactive melt processing. Its melt viscosity and MW can be increased through chemical reactions between organic peroxides (POX) and chain unsaturation or between MgO and carboxyl/hydroxyl end groups. Reactive blending of PP/UP blends through peroxide modification gave finer and more uniform morphology than unreacted blends and at a given PP/UP weight ratio more thermoplastic elastomers-like rheological behavior. This is due to the continuously decreasing viscosity ratio of PP/UP towards unity by the competing reactions between POX and the blend components and formation of PP-UP copolymers which serve as in-situ compatibilizers to promote better interfacial adhesion. Kinetics of the competing reactions were analyzed through a developed model. In addition to POX concentration and mixing efficiency, rheology and morphology of UP/PP bends were significantly affected by the addition of inorganic and organic coagents. Addition of coagents such as a difunctional maleimide, MgO and/or an anhydride functionalized PP during reactive blending offers effective means for tailoring

  14. Structure, reactivity, and biological properties of hidantoines

    International Nuclear Information System (INIS)

    Hydantoin (imidazolidine-2,4-dione) is a 2,4-diketotetrahydroimidazole discovered by Baeyer in 1861. Thiohydantoins and derivatives were prepared, having chemical properties similar to the corresponding carbonyl compounds. Some biological activities (antimicrobial, anticonvulsant, schistosomicidal) are attributed to the chemical reactivity and consequent affinity of hydantoinic rings towards biomacromolecules. Therefore, knowledge about the chemistry of hydantoins has increased enormously. In this review, we present important aspects such as reactivity of hydantoins, acidity of hydantoins, spectroscopy and crystallographic properties, and biological activities of hydantoin and its derivatives. (author)

  15. Programming Reactive Extensions and LINQ

    CERN Document Server

    Liberty, Jesse

    2011-01-01

    Pro Reactive Extensions and LINQ is a deep dive into the next important technology for .NET developers: Reactive Extensions. This in-depth tutorial goes beyond what is available anywhere else to teach how to write WPF, Silverlight, and Windows Phone applications using the Reactive Extensions (Rx) to handle events and asynchronous method calls. Reactive programming allows you to turn those aspects of your code that are currently imperative into something much more event-driven and flexible. For this reason, it's sometimes referred to as LINQ for Events. Reactive programming hinges on the concep

  16. Corticosteroid treatment of experimental autoimmune encephalomyelitis in the Lewis rat results in loss of V beta 8.2+ and myelin basic protein-reactive cells from the spinal cord, with increased total T-cell apoptosis but reduced apoptosis of V beta 8.2+ cells.

    Science.gov (United States)

    McCombe, P A; Nickson, I; Tabi, Z; Pender, M P

    1996-11-01

    We have studied the effects of corticosteroid treatment on the numbers of lymphocytes obtained from the spinal cords of Lewis rats with acute experimental autoimmune encephalomyelitis (EAE) induced by inoculation with myelin basic protein (MBP) and adjuvants. Flow cytometric studies showed that treatment with dexamethasone (4 mg/kg) 8-12 h prior to study on day 14 after inoculation resulted in a reduction in the numbers of CD5+, TCR alpha beta + and V beta 8.2+ cells in the spinal cord. Limiting dilution analysis indicated that dexamethasone treatment 12 h prior to study on day 12 after inoculation reduced the frequencies of MBP-reactive and interleukin-2-responsive lymphocytes in the spinal cord to low levels, but reduced the frequency of concanavalin-A-responsive lymphocytes to a lesser extent. Using propidium iodide staining of nuclear chromatin we also studied lymphocyte apoptosis. Greater numbers of apoptotic cells were found in the cells extracted from the spinal cords of rats, examined on day 14, that had been treated 1-12 h previously with dexamethasone, than in saline-treated controls. This increased level of apoptosis was observed in the CD5+ and TCR alpha beta + cell populations. At 1-4 h after dexamethasone treatment there was a reduction in the selective apoptosis of V beta 8.2+ cells that normally occurs during spontaneous recovery from EAE. Therefore apoptosis of V beta 8.2+ cells cannot explain the reduction in the numbers of V beta 8.2+ cells and MBP-reactive cells in the CNS after dexamethasone treatment. By 8-12 h after dexamethasone treatment the selectivity of the apoptotic process was restored. These studies suggest that a reduction in the number of T-lymphocytes in the central nervous system contributes to the beneficial effects of corticosteroids in EAE. PMID:8898717

  17. Steric effect of ortho subsituents on ester reactivity towards nucleophiles

    International Nuclear Information System (INIS)

    Reactivities of ortho- and para-substituted phenyl acetates in isotopic acyl exchange and in aminolysis were compared. In aminolysis the ortho-substituted esters reacted more rapidly than their para isomers. The increased reactivity is attributed to the proton acceptor ortho substituents. These substituents act as general base catalytic functions in aminolysis but they act differently in isotopic acyl exchange. (author)

  18. Stress Reactivity and Corticolimbic Response to Emotional Faces in Adolescents

    Science.gov (United States)

    Liu, Jie; Chaplin, Tara M.; Wang, Fei; Sinha, Rajita; Mayes, Linda C.; Blumberg, Hilary P.

    2012-01-01

    Objective: Adolescence is a critical period in the development of lifelong patterns of responding to stress. Understanding underpinnings of variations in stress reactivity in adolescents is important, as adolescents with altered stress reactivity are vulnerable to negative risk-taking behaviors including substance use, and have increased lifelong…

  19. Human herpesvirus type 6 reactivation after haematopoietic stem cell transplantation

    NARCIS (Netherlands)

    Pagter, P.J. de; Schuurman, R.; Meijer, Ellen; Baarle, D. van; Sanders, E.A.M.; Boelens, J.J.

    2008-01-01

    Human herpesvirus type 6 (HHV6) is known to reactivate after hematopoetic stem cell transplantation (HSCT) and has been suggested to be associated with increased mortality and severe clinical manifestations, including graft versus host disease (GvHD). The exact etiological role of HHV6 reactivation

  20. Environmental stress, reactivity and ischaemic heart disease.

    Science.gov (United States)

    Krantz, D S; Raisen, S E

    1988-03-01

    This article provides an overview of work in two areas of biobehavioural research: the effects of environmental stress and the role of psychophysiologic reactivity in the development of ischaemic heart disease. Attention is given first to evidence that low socio-economic status, low social support, and occupational settings characterized by high demands and low levels of control over the job are associated with increased coronary risk. Also discussed is a promising animal primate model of social stress and its role in development of coronary atherosclerosis. Next, we discuss physiological responsiveness (reactivity) to emotional stress, which is being studied as a marker of processes involved in the development of cardiovascular disease. Stress and psychophysiological reactivity constitute promising targets for research on biobehavioural antecedents of coronary disease and for clinical intervention studies. However, further evidence is needed before these variables can be regarded as proven coronary risk factors. PMID:3129010

  1. Statistical error analysis of reactivity measurement

    Energy Technology Data Exchange (ETDEWEB)

    Thammaluckan, Sithisak; Hah, Chang Joo [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    After statistical analysis, it was confirmed that each group were sampled from same population. It is observed in Table 7 that the mean error decreases as core size increases. Application of bias factor obtained from this research reduces mean error further. The point kinetic model had been used to measure control rod worth without 3D spatial information of neutron flux or power distribution, which causes inaccurate result. Dynamic Control rod Reactivity Measurement (DCRM) was employed to take into account of 3D spatial information of flux in the point kinetics model. The measured bank worth probably contains some uncertainty such as methodology uncertainty and measurement uncertainty. Those uncertainties may varies with size of core and magnitude of reactivity. The goal of this research is to investigate the effect of core size and magnitude of control rod worth on the error of reactivity measurement using statistics.

  2. Steam-chemical reactivity for irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; McCarthy, K.A.; Oates, M.A.; Petti, D.A.; Pawelko, R.J.; Smolik, G.R. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1998-01-01

    This paper reports the results of an experimental investigation to determine the influence of neutron irradiation effects and annealing on the chemical reactivity of beryllium exposed to steam. The work entailed measurements of the H{sub 2} generation rates for unirradiated and irradiated Be and for irradiated Be that had been previously annealed at different temperatures ranging from 450degC to 1200degC. H{sub 2} generation rates were similar for irradiated and unirradiated Be in steam-chemical reactivity experiments at temperatures between 450degC and 600degC. For irradiated Be exposed to steam at 700degC, the chemical reactivity accelerated rapidly and the specimen experienced a temperature excursion. Enhanced chemical reactivity at temperatures between 400degC and 600degC was observed for irradiated Be annealed at temperatures of 700degC and higher. This reactivity enhancement could be accounted for by the increased specific surface area resulting from development of a surface-connected porosity in the irradiated-annealed Be. (author)

  3. N-acetylcysteine improves arterial vascular reactivity in patients with chronic kidney disease

    DEFF Research Database (Denmark)

    Wittstock, Antje; Burkert, Magdalena; Zidek, Walter;

    2009-01-01

    Patients with stage 5 chronic kidney disease show increased cardiovascular morbidity and mortality that are partly related to impaired arterial vascular reactivity. We investigated whether intravenous administration of the antioxidant acetylcysteine improves arterial vascular reactivity in these...

  4. Disruption of spermatogenesis and differential regulation of testicular estrogen receptor expression in mice after polychlorinated biphenyl exposure

    International Nuclear Information System (INIS)

    Highlights: → Testicular effects of PCBs at low doses which have not been reported before. → PCNA is used as a marker of testicular effect of PCBs. → Differential expression of ERs is correlated with germ cell apoptosis in PCB exposure. -- Abstract: The testicular toxicity of polychlorinated biphenyls (PCBs) has been extensively studied. However, the detailed mechanism is still obscure. In the present study, male C57 mice were treated with different doses of Aroclor 1254 (a commercial PCB mixture) once every 3 days by oral gavage. After exposure to Aroclor 1254 for 50 days, the sperm count decreased in a dose-dependent manner. Cell proliferation and apoptosis are key processes regulating development of the testis, and alterations in these processes may underlie testicular dysgenesis. Our results showed that the germ cell proliferation was inhibited and the apoptosis of the germ cell was induced in a dose-dependent manner after treatment with Aroclor 1254. Although there was no significant change in serum testosterone levels and androgen receptor expression levels after treatment with different dosages of Aroclor 1254, the estradiol levels decreased and the expression of estrogen receptor (ER) β increased in a dose-dependent manner, whereas an elevation of the expression of ERα was only observed in the 50 μg/kg group. The data as a whole suggested that inhibited proliferation and induced apoptosis in germ cells, and a differential regulation of ER, may be involved in the testicular toxicity of PCBs.

  5. Chaotic time series prediction for prenatal exposure to polychlorinated biphenyls in umbilical cord blood using the least squares SEATR model

    Science.gov (United States)

    Xu, Xijin; Tang, Qian; Xia, Haiyue; Zhang, Yuling; Li, Weiqiu; Huo, Xia

    2016-01-01

    Chaotic time series prediction based on nonlinear systems showed a superior performance in prediction field. We studied prenatal exposure to polychlorinated biphenyls (PCBs) by chaotic time series prediction using the least squares self-exciting threshold autoregressive (SEATR) model in umbilical cord blood in an electronic waste (e-waste) contaminated area. The specific prediction steps basing on the proposal methods for prenatal PCB exposure were put forward, and the proposed scheme’s validity was further verified by numerical simulation experiments. Experiment results show: 1) seven kinds of PCB congeners negatively correlate with five different indices for birth status: newborn weight, height, gestational age, Apgar score and anogenital distance; 2) prenatal PCB exposed group at greater risks compared to the reference group; 3) PCBs increasingly accumulated with time in newborns; and 4) the possibility of newborns suffering from related diseases in the future was greater. The desirable numerical simulation experiments results demonstrated the feasibility of applying mathematical model in the environmental toxicology field. PMID:27118260

  6. Analysis of water, sediment and fish to detect contaminations with polychlorinated biphenyls (PVB) in the profile of the river Inde

    International Nuclear Information System (INIS)

    Water, sediment and fish samples of the river Inde in the course from source to mouth were analysed for their contents of polychlorinated biphenyls (6 indicator-congeners). Analysis of the water samples showed no contents of PCB (detection limit: 10 ng/l). The resulting PCB concentration profile of the sediment showed at the upper part of the Inde uniform PCB values of 18 μg/kg dry weight sediment. In the middle part, after the tributary of an industrial influenced brook, the Vicht, the contents of PCB increased precipitously to about 110 μg/kg dry weight. In the further course - downstream near the mouth into the river Rur - the PCB contents in the sediment decreased steplike along a distance of about 20 km resulting in a level of 34 μg/kg dry weight. From the analysed fishes the brook trout (Salmo trutta forma fario) also showed PCB contents dependent on the position in the river where they were cought. In relation to muscle lipid content the averange values at the upper part of the river amounted to 6 mg/kg, in the middle part to ca 38 mg/kg and downstream to ca 8 mg/kg extractable lipid basis. Because of absence at some sampling points for the roach (Rutilus rutilus) and gudgeon (Gobio gobio) an analogues correlation could not be found. This fishes showed concentrations of PCB ranging from 3 to 5 mg/kg extractable lipid basis. (orig.)

  7. Formation of Polychlorinated Biphenyls on Secondary Copper Production Fly Ash: Mechanistic Aspects and Correlation to Other Persistent Organic Pollutants

    Science.gov (United States)

    Jiang, Xiaoxu; Liu, Guorui; Wang, Mei; Zheng, Minghui

    2015-09-01

    Emission of unintentionally formed polychlorinated biphenyls (PCBs) from industrial thermal processes is a global issue. Because the production and use of technical PCB mixtures has been banned, industrial thermal processes have become increasingly important sources of PCBs. Among these processes, secondary copper smelting is an important PCB source in China. In the present study, the potential for fly ash-mediated formation of PCBs in the secondary copper industry, and the mechanisms involved, were studied in laboratory thermochemical experiments. The total PCB concentrations were 37-70 times higher than the initial concentrations. Thermochemical reactions on the fly ash amplified the potential toxic equivalents of PCBs. The formation of PCBs over time and the effect of temperature were investigated. Based on analyses of PCB homologue profiles with different reaction conditions, a chlorination mechanism was proposed for forming PCBs in addition to a de novo synthesis mechanism. The chlorination pathway was supported by close correlations between each pair of adjacent homologue groups. Formation of PCBs and multiple persistent organic pollutants, including polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated naphthalenes, occurred during the tests, indicating that these compounds may share similar formation mechanisms.

  8. Soil concentrations, occurrence, sources and estimation of air-soil exchange of polychlorinated biphenyls in Indian cities.

    Science.gov (United States)

    Chakraborty, Paromita; Zhang, Gan; Li, Jun; Selvaraj, Sakthivel; Breivik, Knut; Jones, Kevin C

    2016-08-15

    Past studies have shown potentially increasing levels of polychlorinated biphenyls (PCBs) in the Indian environment. This is the first attempt to investigate the occurrence of PCBs in surface soil and estimate diffusive air-soil exchange, both on a regional scale as well as at local level within the metropolitan environment of India. From the north, New Delhi and Agra, east, Kolkata, west, Mumbai and Goa and Chennai and Bangalore in the southern India were selected for this study. 33 PCB congeners were quantified in surface soil and possible sources were derived using positive matrix factorization model. Net flux directions of PCBs were estimated in seven major metropolitan cities of India along urban-suburban-rural transects. Mean Σ33PCBs concentration in soil (12ng/g dry weight) was nearly twice the concentration found in global background soil, but in line with findings from Pakistan and urban sites of China. Higher abundance of the heavier congeners (6CB-8CB) was prevalent mostly in the urban centers. Cities like Chennai, Mumbai and Kolkata with evidence of ongoing PCB sources did not show significant correlation with soil organic carbon (SOC). This study provides evidence that soil is acting as sink for heavy weight PCB congeners and source for lighter congeners. Atmospheric transport is presumably a controlling factor for occurrence of PCBs in less polluted sites of India. PMID:27136304

  9. Bioaccumulation of polychlorinated biphenyls and metals from contaminated sediment by freshwater prawns, Macrobrachium rosenbergii and clams, Corbicula fluminea

    Energy Technology Data Exchange (ETDEWEB)

    Tatem, H.E.

    1986-02-01

    Freshwater prawns, Macrobrachium rosenbergii, and clams, Corbicula Fluminea, were exposed for 48 or 50 days to three concentrations of a river sediment that contained environmental contaminants such as polychlorinated biphenyls (PCBs) and metals. The PCB sediment bioaccumulation factors (BAF) for prawns ranged from 0.11 to 0.90 for 1242 and 0.20 to 2.40 for 1254, and were highest for animals exposed to 10% sediment. Exposed clams also accumulated PCBs (1242 + 1254) from the sediment. Sediment BAFs for clams were 0.54 to 12.52 and were highest for animals exposed to 10% sediment. Analyses of clams for metals showed lead (Pb) in exposed animals at higher concentrations compared with controls. Bioaccumulation of Pb differed from PCB in that the Pb concentrations did not increase over time and concentrations were higher among animals exposed to 10% sediment compared to animals exposed to 100% sediment. Sediment 11-80 contained 99 mg/kg of Pb while exposed animals, at 48 days, contained approximately 2.2 mg/kg Pb. Analysis of clams for cadmium (Cd) showed exposed animals contained less Cd than controls.

  10. Chaotic time series prediction for prenatal exposure to polychlorinated biphenyls in umbilical cord blood using the least squares SEATR model

    Science.gov (United States)

    Xu, Xijin; Tang, Qian; Xia, Haiyue; Zhang, Yuling; Li, Weiqiu; Huo, Xia

    2016-04-01

    Chaotic time series prediction based on nonlinear systems showed a superior performance in prediction field. We studied prenatal exposure to polychlorinated biphenyls (PCBs) by chaotic time series prediction using the least squares self-exciting threshold autoregressive (SEATR) model in umbilical cord blood in an electronic waste (e-waste) contaminated area. The specific prediction steps basing on the proposal methods for prenatal PCB exposure were put forward, and the proposed scheme’s validity was further verified by numerical simulation experiments. Experiment results show: 1) seven kinds of PCB congeners negatively correlate with five different indices for birth status: newborn weight, height, gestational age, Apgar score and anogenital distance; 2) prenatal PCB exposed group at greater risks compared to the reference group; 3) PCBs increasingly accumulated with time in newborns; and 4) the possibility of newborns suffering from related diseases in the future was greater. The desirable numerical simulation experiments results demonstrated the feasibility of applying mathematical model in the environmental toxicology field.

  11. Combinatorial fabrication and studies of 4,4'-bis(9-carbazolyl) biphenyl (CBP)-based UV-violet OLED arrays

    Science.gov (United States)

    Zou, L.; Savvate'ev, Vadim; Booher, J.; Kim, Chang-Hwan; Shinar, Joseph

    2002-02-01

    Arrays of UV-violet [indium tin oxide (ITO)]/[copper phthalocyanine (CuPc)]/[4,4'-bis(9- carbazolyl)biphenyl(CBP)]/[2-(4-biphenylyl)-5-(4-tert- butylphenyl)-1,3,4-oxadiazole(Bu-PBD)]/CsF/Al organic light- emitting devices (OLEDs), fabricated combinatorially using a sliding shutter technique, are described. Comparison of the electroluminescence spectrum with the photoluminescence spectrum of CBP indicates that the emission originates from the bulk of that layer. However, due to the high gap of CBP and the strong hole capture cross section of perylene contaminants, it was difficult to completely eliminate the emission from the latter. In arrays of devices in which the thickness of the CuPc and Bu-PBD were varied, but that of CBP was fixed at 50 nm, the optimal radiance R was obtained at CuPc and Bu-PBD thicknesses of 15 and 18 nm, respectively. At 10 mA/Cm2, R was 0.38 mW/cm2, i.e., the external quantum efficiency was 1.25%; R increased to ~1.2 mW/cm2 at 100 mA/cm2.

  12. 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.

  13. Optimizing Polychlorinated Biphenyl Degradation by Flavonoid-Induced Cells of the Rhizobacterium Rhodococcus erythropolis U23A.

    Directory of Open Access Journals (Sweden)

    Thi Thanh My Pham

    Full Text Available There is evidence that many plant secondary metabolites may act as signal molecules to trigger the bacterial ability to metabolize polychlorinated biphenyls (PCBs during the rhizoremediation process. However, the bases for the PCB rhizoremediation process are still largely unknown. The rhizobacterium Rhodococcus erythropolis U23A is unable to use flavanone as a growth substrate. However, on the basis of an assay that monitors the amount of 4-chlorobenzoate produced from 4-chlorobiphenyl by cells grown co-metabolically on flavanone plus sodium acetate, this flavonoid was previously found to be a potential inducer of the U23A biphenyl catabolic pathway. In this work, and using the same assay, we identified ten other flavonoids that did not support growth, but that acted as inducers of the U23A biphenyl pathway, and we confirmed flavonoid induction of the biphenyl catabolic pathway using quantitative real-time polymerase chain reaction (RT-qPCR on the bphA gene. We also examined the effect of the growth co-substrate on flavonoid induction. Sodium acetate was replaced by glucose, mannose, sucrose, or mannitol, which are sugars found in plant root exudates. The data showed that the level of induction of strain U23A biphenyl-degrading enzymes was significantly influenced by the nature and concentration of the flavonoid in the growth medium, as well as by the substrate used for growth. Sucrose allowed for an optimal induction response for most flavonoids. Some flavonoids, such as flavone and isoflavone, were better inducers of the biphenyl catabolic enzymes than biphenyl itself. We also found that all flavonoids tested in this work were metabolized by strain U23A during co-metabolic growth, but that the metabolite profiles, as well as the level of efficiency of degradation, differed for each flavonoid. To obtain insight into how flavonoids interact with strain U23A to promote polychlorinated biphenyl (PCB degradation, we determined the concentration of

  14. Bioaccumulation of hydroxylated polychlorinated biphenyls and pentachlorophenol in the serum of northern elephant seal pups (Mirounga angustirostris)

    International Nuclear Information System (INIS)

    Northern elephant seals (NES) (Mirounga angustirostris) from the Año Nuevo State Reserve (CA, USA) were sampled at 1-, 4-, 7- and 10-week post-weaning. Concentrations of hydroxylated polychlorinated biphenyls (HO-PCBs) and their parent PCBs were measured in the serum of each individual. The ΣHO-PCB concentrations in the serum increased significantly between early and late fast (from 282±20 to 529±31 pg/mL). This increase might result from a mobilisation of HO-PCBs transferred from the mother during gestation and/or lactation and stored in the pup's liver. Food deprivation has been shown to exacerbate biotransformation capacities in mammals, birds and fish. The HO-penta-CBs was the predominant homologue group, followed by HO-hexa-CBs and HO-hepta-CBs. No preferential pathway for the metabolism of HO-PCBs (HO-direct insertion or NIH-shift of a chlorine atom) could be evidenced. The concentrations of pentachlorophenol (PCP) in the serum of weaned NES increased from 103±7 pg/mL at early fast to 246±41 pg/mL at late fast, which is within the range of PCP concentrations usually encountered in marine mammals. - Highlights: • Σ HO-PCB concentrations in serum significantly increased between early and late fast. • The HO-penta-CBs were the predominant homologue group measured in serum. • No preferential pathway for the metabolism of HO-PCBs could be evidenced. • PCP concentrations in serum significantly increased between early and late fast

  15. Bioaccumulation of hydroxylated polychlorinated biphenyls and pentachlorophenol in the serum of northern elephant seal pups (Mirounga angustirostris)

    Energy Technology Data Exchange (ETDEWEB)

    Louis, Caroline, E-mail: caroline.louis@uclouvain.be [Institut des Sciences de la Vie, UCLouvain, Croix du Sud 2/L7.05.08, 1348 Louvain-la-Neuve (Belgium); Covaci, Adrian [Department of Pharmaceutical Sciences, Toxicological Center, Campus Drie Eiken, Universiteit Antwerpen, Universiteitsplein 1, 2610 Wilrijk (Belgium); Stas, Marie [Institut des Sciences de la Vie, UCLouvain, Croix du Sud 2/L7.05.08, 1348 Louvain-la-Neuve (Belgium); Crocker, Daniel E. [Department of Biology, Sonoma State University, 1801 East Cotati Ave, Rohnert Park, CA 94928 (United States); Malarvannan, Govindan [Department of Pharmaceutical Sciences, Toxicological Center, Campus Drie Eiken, Universiteit Antwerpen, Universiteitsplein 1, 2610 Wilrijk (Belgium); Dirtu, Alin C. [Department of Pharmaceutical Sciences, Toxicological Center, Campus Drie Eiken, Universiteit Antwerpen, Universiteitsplein 1, 2610 Wilrijk (Belgium); Department of Chemistry, “Al. I. Cuza” University of Iasi, 700506 Iasi (Romania); Debier, Cathy [Institut des Sciences de la Vie, UCLouvain, Croix du Sud 2/L7.05.08, 1348 Louvain-la-Neuve (Belgium)

    2015-01-15

    Northern elephant seals (NES) (Mirounga angustirostris) from the Año Nuevo State Reserve (CA, USA) were sampled at 1-, 4-, 7- and 10-week post-weaning. Concentrations of hydroxylated polychlorinated biphenyls (HO-PCBs) and their parent PCBs were measured in the serum of each individual. The ΣHO-PCB concentrations in the serum increased significantly between early and late fast (from 282±20 to 529±31 pg/mL). This increase might result from a mobilisation of HO-PCBs transferred from the mother during gestation and/or lactation and stored in the pup's liver. Food deprivation has been shown to exacerbate biotransformation capacities in mammals, birds and fish. The HO-penta-CBs was the predominant homologue group, followed by HO-hexa-CBs and HO-hepta-CBs. No preferential pathway for the metabolism of HO-PCBs (HO-direct insertion or NIH-shift of a chlorine atom) could be evidenced. The concentrations of pentachlorophenol (PCP) in the serum of weaned NES increased from 103±7 pg/mL at early fast to 246±41 pg/mL at late fast, which is within the range of PCP concentrations usually encountered in marine mammals. - Highlights: • Σ HO-PCB concentrations in serum significantly increased between early and late fast. • The HO-penta-CBs were the predominant homologue group measured in serum. • No preferential pathway for the metabolism of HO-PCBs could be evidenced. • PCP concentrations in serum significantly increased between early and late fast.

  16. A Universal Reactive Machine

    DEFF Research Database (Denmark)

    Andersen, Henrik Reif; Mørk, Simon; Sørensen, Morten U.

    1997-01-01

    Turing showed the existence of a model universal for the set of Turing machines in the sense that given an encoding of any Turing machine asinput the universal Turing machine simulates it. We introduce the concept of universality for reactive systems and construct a CCS processuniversal in the...... sense that, given an encoding of any CCS process, it behaves like this process up to weak bisimulation. This construction has arather non-constructive use of silent actions and we argue that this would be the case for any universal CCS process....

  17. Evaluation of the applicable reactivity range of a reactivity computer for a CANDU-6 reactor

    International Nuclear Information System (INIS)

    Recently, a CANDU digital reactivity computer system (CDRCS) to measure the worth of the liquid zone controller in a CANDU-6 was developed and successfully applied to a physics test of refurbished Wolsong Unit 1. In advance of using the CDRCS, its measurable reactivity range should be investigated and confirmed. There are two reasons for this investigation. First, the CANDU-6 has a larger reactor and smaller excore detectors than a general PWR and consequently the measured reactivity is likely to reflect the peripheral power variation only, not the whole core. The second reason is photo neutrons generated from the interaction of the moderator and gamma-rays, which are never considered in a PWR. To evaluate the limitations of the CDRCS, several tens of three-dimensional steady and transient simulations were performed. The simulated detector signals were used to obtain the dynamic reactivity. The difference between the dynamic reactivity and the static worth increases in line with the water level changes. The maximum allowable reactivity was determined to be 1.4 mk in the case of CANDU-6 by confining the difference to less than 1%.

  18. Serum Levels of Anticyclic Citrullinated Peptide Antibodies, Interleukin-6, Tumor Necrosis Factor-α, and C-Reactive Protein Are Associated with Increased Carotid Intima-Media Thickness: A Cross-Sectional Analysis of a Cohort of Rheumatoid Arthritis Patients without Cardiovascular Risk Factors

    Directory of Open Access Journals (Sweden)

    Mónica Vázquez-Del Mercado

    2015-01-01

    Full Text Available The main cause of death in rheumatoid arthritis (RA is cardiovascular events. We evaluated the relationship of anticyclic citrullinated peptide (anti-CCP antibody levels with increased carotid intima-media thickness (cIMT in RA patients. Methods. Forty-five anti-CCP positive and 37 anti-CCP negative RA patients, and 62 healthy controls (HC were studied. All groups were assessed for atherogenic index of plasma (AIP and cIMT. Anti-CCP, C-reactive protein (CRP, and levels of tumor necrosis factor alpha (TNFα and interleukin-6 (IL-6 were measured by enzyme-linked immunosorbent assay (ELISA. Results. The anti-CCP positive RA patients showed increased cIMT compared to HC and anti-CCP negative (P<0.001. Anti-CCP positive versus anti-CCP negative RA patients, had increased AIP, TNFα and IL-6 (P<0.01, and lower levels of high density lipoprotein cholesterol (HDL-c (P=0.02. The cIMT correlated with levels of anti-CCP (r=0.513, P=0.001, CRP (r=0.799, P<0.001, TNFα (r=0.642, P=0.001, and IL-6 (r=0.751, P<0.001. In multiple regression analysis, cIMT was associated with CRP (P<0.001 and anti-CCP levels (P=0.03. Conclusions. Levels of anti-CCP and CRP are associated with increased cIMT and cardiovascular risk supporting a clinical role of the measurement of cIMT in RA in predicting and preventing cardiovascular events.

  19. Serum Levels of Anticyclic Citrullinated Peptide Antibodies, Interleukin-6, Tumor Necrosis Factor-α, and C-Reactive Protein Are Associated with Increased Carotid Intima-Media Thickness: A Cross-Sectional Analysis of a Cohort of Rheumatoid Arthritis Patients without Cardiovascular Risk Factors

    Science.gov (United States)

    Vázquez-Del Mercado, Mónica; Nuñez-Atahualpa, Lourdes; Figueroa-Sánchez, Mauricio; Gómez-Bañuelos, Eduardo; Rocha-Muñoz, Alberto Daniel; Martín-Márquez, Beatriz Teresita; Martínez-García, Erika Aurora; Macias-Reyes, Héctor; Gamez-Nava, Jorge Ivan; Navarro-Hernandez, Rosa Elena; Nuñez-Atahualpa, María Alejandra; Andrade-Garduño, Javier

    2015-01-01

    The main cause of death in rheumatoid arthritis (RA) is cardiovascular events. We evaluated the relationship of anticyclic citrullinated peptide (anti-CCP) antibody levels with increased carotid intima-media thickness (cIMT) in RA patients. Methods. Forty-five anti-CCP positive and 37 anti-CCP negative RA patients, and 62 healthy controls (HC) were studied. All groups were assessed for atherogenic index of plasma (AIP) and cIMT. Anti-CCP, C-reactive protein (CRP), and levels of tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). Results. The anti-CCP positive RA patients showed increased cIMT compared to HC and anti-CCP negative (P < 0.001). Anti-CCP positive versus anti-CCP negative RA patients, had increased AIP, TNFα and IL-6 (P < 0.01), and lower levels of high density lipoprotein cholesterol (HDL-c) (P = 0.02). The cIMT correlated with levels of anti-CCP (r = 0.513, P = 0.001), CRP (r = 0.799, P < 0.001), TNFα (r = 0.642, P = 0.001), and IL-6 (r = 0.751, P < 0.001). In multiple regression analysis, cIMT was associated with CRP (P < 0.001) and anti-CCP levels (P = 0.03). Conclusions. Levels of anti-CCP and CRP are associated with increased cIMT and cardiovascular risk supporting a clinical role of the measurement of cIMT in RA in predicting and preventing cardiovascular events. PMID:25821796

  20. Differential expression of biphenyl synthase gene family members in fire-blight-infected apple 'Holsteiner Cox'.

    Science.gov (United States)

    Chizzali, Cornelia; Gaid, Mariam M; Belkheir, Asma K; Hänsch, Robert; Richter, Klaus; Flachowsky, Henryk; Peil, Andreas; Hanke, Magda-Viola; Liu, Benye; Beerhues, Ludger

    2012-02-01

    Fire blight, caused by the bacterium Erwinia amylovora, is a devastating disease of apple (Malus × domestica). The phytoalexins of apple are biphenyls and dibenzofurans, whose carbon skeleton is formed by biphenyl synthase (BIS), a type III polyketide synthase. In the recently published genome sequence of apple 'Golden Delicious', nine BIS genes and four BIS gene fragments were detected. The nine genes fall into four subfamilies, referred to as MdBIS1 to MdBIS4. In a phylogenetic tree, the BIS amino acid sequences from apple and Sorbus aucuparia formed an individual cluster within the clade of the functionally diverse type III polyketide synthases. cDNAs encoding MdBIS1 to MdBIS4 were cloned from fire-blight-infected shoots of apple 'Holsteiner Cox,' heterologously expressed in Escherichia coli, and functionally analyzed. Benzoyl-coenzyme A and salicoyl-coenzyme A were the preferred starter substrates. In response to inoculation with E. amylovora, the BIS3 gene was expressed in stems of cv Holsteiner Cox, with highest transcript levels in the transition zone between necrotic and healthy tissues. The transition zone was the accumulation site of biphenyl and dibenzofuran phytoalexins. Leaves contained transcripts for BIS2 but failed to form immunodetectable amounts of BIS protein. In cell cultures of apple 'Cox Orange,' expression of the BIS1 to BIS3 genes was observed after the addition of an autoclaved E. amylovora suspension. Using immunofluorescence localization under a confocal laser-scanning microscope, the BIS3 protein in the transition zone of stems was detected in the parenchyma of the bark. Dot-shaped immunofluorescence was confined to the junctions between neighboring cortical parenchyma cells. PMID:22158676

  1. Two-hit exposure to polychlorinated biphenyls at gestational and juvenile life stages: 2. Sex-specific neuromolecular effects in the brain.

    Science.gov (United States)

    Bell, Margaret R; Hart, Bethany G; Gore, Andrea C

    2016-01-15

    Exposures to polychlorinated biphenyls (PCBs) during early development have long-lasting, sexually dimorphic consequences on adult brain and behavior. However, few studies have investigated their effects during juvenile development, a time when increases in pubertal hormones influence brain maturation. Here, male and female Sprague Dawley rats were exposed to PCBs (Aroclor 1221, 1 mg/kg/day) or vehicle prenatally, during juvenile development, or both, and their effects on serum hormone concentrations, gene expression, and DNA methylation were assessed in adulthood. Gene expression in male but not female brains was affected by 2-hits of PCBs, a result that paralleled behavioral effects of PCBs. Furthermore, the second hit often changed the effects of a first hit in complex ways. Thus, PCB exposures during critical fetal and juvenile developmental periods result in unique neuromolecular phenotypes, with males most vulnerable to the treatments. PMID:26620572

  2. Polychlorinated biphenyls (PCBs) in the frame of the dismantling of nuclear facilities

    International Nuclear Information System (INIS)

    During construction and maintenance of nuclear facilities PCB (polychlorinated biphenyls) containing paints were used in a large extent in the past. The WAK dismantling and disposal Company has dismantles such facilities and identified the PCB in the buildings. Besides the radionuclides the conventional hazardous material group of the PCBs has also to be disposed. The respective legal regulations have to be considered. In the frame of the contribution the radiological release of building structures with respect to re-use or demolition and residual PCB containing materials is discussed. The radiological disposal in final repositories and the conventional disposal regulations for releasable residual wastes are reported.

  3. Whole-Cell Fluorescent Biosensors for Bioavailability and Biodegradation of Polychlorinated Biphenyls

    Directory of Open Access Journals (Sweden)

    David Ryan

    2010-02-01

    Full Text Available Whole-cell microbial biosensors are one of the newest molecular tools used in environmental monitoring. Such biosensors are constructed through fusing a reporter gene such as lux, gfp or lacZ,to a responsive promoter. There have been many reports of the applications of biosensors, particularly their use in assaying pollutant toxicity and bioavailability. This paper reviews the basic concepts behind the construction of whole-cell microbial biosensors for pollutant monitoring, and describes the applications of two such biosensors for detecting the bioavailability and biodegradation of Polychlorinated Biphenyls (PCBs.

  4. Remobilization of polychlorinated biphenyls from sediment and its consequences for their transport in river waters

    OpenAIRE

    Gdaniec-Pietryka, Monika; Mechlińska, Agata; Wolska, Lidia; Gałuszka, Agnieszka; Namieśnik, Jacek

    2012-01-01

    A laboratory experiment was performed to examine the remobilization of indicator polychlorinated biphenyls (iPCBs) from sediments and its results were applied to the real-world data for explaining the transport of PCBs in river. Seven PCB concentrations were determined in three series of model water–sediment systems (3 g of river sediment, three different volumes of distilled water (0.5, 0.25, and 0.15 ml), and 5 mg of biocide) after 11 days of incubation. Solid-phase extraction was used for ...

  5. Isolation of bioactive biphenyl compounds from the twigs of Chaenomeles sinensis.

    Science.gov (United States)

    Kim, Chung Sub; Subedi, Lalita; Kwon, Oh Kil; Kim, Sun Yeou; Yeo, Eui-Ju; Choi, Sang Un; Lee, Kang Ro

    2016-01-15

    Investigation of the MeOH extract of Chaenomeles sinensis twigs resulted in the isolation of seven biphenyl compounds (1-7) including a new compound, chaenomin (1). The chemical structures of the isolated compounds were elucidated by extensive NMR data ((1)H and (13)C NMR, (1)H-(1)H COSY, HSQC and HMBC), specific optical rotation, and chemical reaction. Compounds 2 and 6 showed potent cytotoxic activities against four cancer cell lines (A549, SK-OV-3, SK-MEL-2, and HCT15), and compound 7 exhibited potent anti-neuroinflammatory and NGF-potentiating activity. PMID:26706168

  6. Management of the Polychlorinated Biphenyl Inventory in the Double-Shell Tank (DST) System

    International Nuclear Information System (INIS)

    This document presents the significant management features for polychlorinated biphenyl (PCB) wastes in the double-shell tank (DST) system, discussed in Sections 2.0 through 4.0. Section 2.0 delineates the decision limits for acceptance of PCB wastes into and within the DST system. Section 3.0 briefly discusses the process for obtaining a baseline PCB inventory. The PCB inventory tracking system for waste transfers into and within the DST system is described in Section 4.0. The implementation of this PCB management plan is described in Section 5.0. Section 6.0 names the organizations responsible for implementation of the plans elements

  7. Rapid separation of polychlorinated biphenyls from DDT and its analogues on silica gel

    Science.gov (United States)

    Snyder, Diane; Reinert, Robert E.

    1971-01-01

    Polychlorinated biphenyls (PCB's), which are used in industry worldwide (i), have been found as residues in numerous wildlife species (2-7). Because of the similarity in chemical characteristics, PCB compounds interfere with gas liquid chromatographic (GLC) analysis of certain chlorinated hydrocarbon insecticides (8). In the present study, we sought a rapid microanalytical procedure for separation of PCB's from DDT and its analogues before analysis with GLC. A small silica gel column was found to be suitable for removing two of the Aroclor series of PCB's (1254 and 1260) from DDT and its analogues.

  8. Polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) in urban soils of Greater London, UK

    OpenAIRE

    Vane, Christopher H.; Kim, Alexander W.; Beriro, Darren J.; Cave, Mark R.; Knights, Katherine; Moss-Hayes, Vicky; Nathanail, Paul C.

    2014-01-01

    Surface soils from a 19 km2 area in east London, UK were analysed for polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) (n = 76). ∑16 PAH ranged from 4 to 67 mg/kg (mean, 18 mg/kg) and ∑50 PAH ranged from 6 to 88 mg/kg (mean, 25 mg/kg). ∑7 PCB ranged from 1 to 750 μg/kg (mean, 22 μg/kg) and ∑tri-hepta PCB ranged 9 to 2600 μg/kg (mean, 120 μg/kg). Compared to other international cities concentrations were similar for PAH but higher for PCB. Normal background concentrat...

  9. 1-[(Biphenyl-4-yl(phenylmethyl]-1H-imidazole (bifonazole

    Directory of Open Access Journals (Sweden)

    Lynne S. Taylor

    2010-10-01

    Full Text Available In the title compound, C22H18N2, the dihedral angles formed by the imidazole ring with the phenyl ring and the benzene ring of the biphenyl group are 87.02 (5 and 78.20 (4°, respectively. In the crystal, molecules interact through intermolecular C—H...N hydrogen bonds, forming chains parallel to the b axis. These chains are further linked into a three-dimensional network by C—H...π stacking interactions

  10. Synthesis of new biphenyl-substituted quinoline derivatives, preliminary screening and docking studies

    Indian Academy of Sciences (India)

    Nellisara D Shashikumar; Ganganaika Krishnamurthy; Halehatti S Bhojyanaik; Mayasandra R Lokesh; Kaginalli S Jithendrakumara

    2014-01-01

    New quinoline derivatives containing biphenyl ring were synthesized and characterized by IR, 1H NMR and mass spectral studies. The synthesized compounds were screened for antimicrobial, anthelmintic activities as well as free radical scavenging property against the DPPH radical. The minimum inhibition concentration values showed promising inhibiting activity and are potent biological agents. The compounds showed minimum binding energy towards -tubulin. The compounds 11a, 11c, 13c and 13d have good affinity towards the active pocket and may be considered as a good inhibitor of -tubulin.

  11. Separation of Biphenyl Nitrile Compounds by Microemulsion Electrokinetic Chromatography with Mixed Surfactants

    Institute of Scientific and Technical Information of China (English)

    Su Xuan GONG; Tao BO; Lan HUANG; Ke An LI; Hu Wei LIU

    2004-01-01

    A mixture of nine biphenyl nitrile compounds with high hydrophobicity and similar structures was successfully separated by microemulsion electrokinetic chromatography (MEEKC) within 30 min. The buffer system contained 100 mmol/L sodium dodecyl sulfate (SDS), 80 mmol/L sodium cholate (SC), 0.81% heptane, 7.5% n-butanol, 10% acetonitrile and 10 mmol/L borate. The addition of SC, organic modifiers, sample preparation and temperature all showed remarkable effect on the separation. Meanwhile, the MEEKC method was briefly compared with micellar electrokinetic chromatography (MEKC) method.

  12. Controlling Material Reactivity Using Architecture.

    Science.gov (United States)

    Sullivan, Kyle T; Zhu, Cheng; Duoss, Eric B; Gash, Alexander E; Kolesky, David B; Kuntz, Joshua D; Lewis, Jennifer A; Spadaccini, Christopher M

    2016-03-01

    3D-printing methods are used to generate reactive material architectures. Several geometric parameters are observed to influence the resultant flame propagation velocity, indicating that the architecture can be utilized to control reactivity. Two different architectures, channels and hurdles, are generated, and thin films of thermite are deposited onto the surface. The architecture offers an additional route to control, at will, the energy release rate in reactive composite materials. PMID:26669517

  13. Wastewater treatment after reactive printing

    OpenAIRE

    Šostar-Turk, Sonja; Simonič, Marjana; Petrinić, Irena

    2012-01-01

    Membrane filtration of wastewater after textile printing with reactive dyes isdescribed. The wastewater from a Slovenian factory, whose output is approx. 80% reactive dyes printed and dyed on cotton, was studied. In particular, the presence of urea, sodium alginate, oxidation agent and reactive dyes, used forthe printing paste preparation, in the wastewater was studied. Chemical analyses of actual, non-purified, wastewater showed that many Slovenian regulations were exceeded. The study of mem...

  14. Characterization of the biosorption and biodegradation properties of Ensifer adhaerens: A potential agent to remove polychlorinated biphenyls from contaminated water.

    Science.gov (United States)

    Xu, Li; Chen, Xiong; Li, Huixin; Hu, Feng; Liang, Mingxiang

    2016-01-25

    Ensifer adhaerens is a soil bacterium known for its potential to remove pollutants from the environment. We investigated the contributions of biosorption and biodegradation to the process of polychlorinated biphenyl (PCB) removal from water by living or heat-killed E. adhaerens with different incubation times. We examined the physicochemical properties of E. adhaerens, including its membrane surface moieties, extracellular polymeric substances, and defense-related enzyme activities. In addition, we measured the biosorption and biodegradation of different PCB congeners. We found that removal of PCBs by heat-killed E. adhaerens was attributed to biosorption only, while both biosorption and biodegradation were responsible for the dissipation of PCBs by live E. adhaerens. Biosorption initially plays a major role in PCB removal, but biodegradation becomes increasingly important with increased incubation time. The results of infrared spectroscopy analysis showed that bacterial lipids, proteins, and polysaccharides, which offer abundant binding sites, are responsible for the biosorption of PCBs. Biodegradation was correlated with loosely bound polysaccharides and defense-related enzyme activities that could increase the pollutant's solubility and facilitate further degradation. The PCB congeners exhibited different biosorption and biodegradation patterns, and the patterns were correlated with the octanol-water partition coefficients (Kow) of the congeners. The more hydrophobic organic compounds tended to have higher biosorption, but lower biodegradation capacities. These results indicate that E. adhaerens-mediated biosorption and biodegradation of PCBs are dependent on the status of the strain, the incubation time, and the PCB congener present, and suggest guidelines for PCB removal from water. PMID:26476319

  15. Massive florid reactive periostitis

    International Nuclear Information System (INIS)

    Florid reactive periostitis is a rare, benign process usually occurring in the small, tubular bones of the hands and feet. Typically the lesion occurs in an adolescent or young adult and presents as a small area of pain and erythema over the affected bone. Although the histologic features may suggest malignancy, there is usually little radiographic evidence to support such a diagnosis. In the following report an unusual example of this entity is described whose large size and relentless local progression led to initial diagnostic uncertainty and eventual aggressive management. This case suggests that a wide spectrum of radiologic and morphologic changes may be seen in this entity and that a seemingly unrelated genetic disease may alter the typical clinical course. (orig.)

  16. Coke Reactivity in Simulated Blast Furnace Shaft Conditions

    Science.gov (United States)

    Haapakangas, Juho; Suopajärvi, Hannu; Iljana, Mikko; Kemppainen, Antti; Mattila, Olli; Heikkinen, Eetu-Pekka; Samuelsson, Caisa; Fabritius, Timo

    2016-08-01

    Despite the fact that H2 and H2O are always present in the gas atmosphere of a blast furnace shaft, their role in the solution-loss reactions of coke has not been thoroughly examined. This study focuses on how H2 and H2O affect the reaction behavior and whether a strong correlation can be found between reactivity in the conditions of the CRI test (Coke Reactivity Index) and various simulated blast furnace shaft gas atmospheres. Partial replacement of CO/CO2 with H2/H2O was found to significantly increase the reactivity of all seven coke grades at 1373 K (1100 °C). H2 and H2O, however, did not have a significant effect on the threshold temperature of gasification. The reactivity increasing effect was found to be temperature dependent and clearly at its highest at 1373 K (1100 °C). Mathematical models were used to calculate activation energies for the gasification, which were notably lower for H2O gasification compared to CO2 indicating the higher reactivity of H2O. The reactivity results in gas atmospheres with CO2 as the sole gasifying component did not directly correlate with reactivity results in gases also including H2O, which suggests that the widely used CRI test is not entirely accurate for estimating coke reactivity in the blast furnace.

  17. Analysis the mixtures of polyphenyls by gas chromatrogaphie. 1.- Area response for biphenyl and terphenyls relative to triphenylmethane

    International Nuclear Information System (INIS)

    The relative performances of the thermal conductivity and flame ionization detectors towards triphenylmethane were investigated for each one of the components of biphenyl of biphenyl and terphenyl mixtures. The influence of the concentration of the considered compound as well as the influence derived from the present of all other components on the above-mentioned relative performance were studied. A 2 m long column filled with 50-70 mesh stomacher containing 20% apiezon L was used to carry out the study with the thermal conductivity detector by keeping the column at 300 degree centigree using helium gas as carrier. (Author) 13 refs

  18. Airway vascular reactivity and vascularisation in human chronic airway disease

    NARCIS (Netherlands)

    Bailey, Simon R; Boustany, Sarah; Burgess, Janette K; Hirst, Stuart J; Sharma, Hari S; Simcock, David E; Suravaram, Padmini R; Weckmann, Markus

    2009-01-01

    Altered bronchial vascular reactivity and remodelling including angiogenesis are documented features of asthma and other chronic inflammatory airway diseases. Expansion of the bronchial vasculature under these conditions involves both functional (vasodilation, hyperperfusion, increased microvascular

  19. Toxicity of polychlorinated biphenyl with special reference to porphyrin metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Sano, S.; Kawanishi, S.; Seki, Y.

    1985-02-01

    Oral administration of a commercial PCB mixture to chickens caused a hepatic-type porphyria characterized by hepatic accumulation and urinary excretion of uroporphyrin. To clarify the mechanism of the porphyrinogenic activity of these PCBs, the authors studied the structural requirement of synthetic PCB for porphyrinogenic activities by using the cultured chick embryo liver cells and examined the relationship between induction of delta-aminolevulinic acid (ALA) synthetase and inhibition of uroporphyrinogen decarboxylase. They established that the porphyrinogenic effect of PCBs exhibits a sharply defined structure-activity relationship in that only 3,4,3',4'-tetrachlorobiphenyl and 3,4,5,3',4',5'-hexachlorobiphenyl produced a marked accumulation of uroporphyrin. They also demonstrated that in ALA-supplemented cultures, these same compounds lead to accumulation of a large amount of uroporphyrin III, whereas with other PCBs, which were weak inducers of porphyrin synthesis, the accumulated porphyrin was mostly protoporphyrin. Kinetic studies of the sequential decarboxylation of uroporphyrinogen with purified uroporphyrinogen decarboxylase were performed. The 3,4,3',4'-tetrachlorobiphenyl and 3,4,5,3',4',5'-hexachlorobiphenyl strongly inhibit uroporphyrinogen decarboxylase directly at two steps. The results confirmed that porphyrinogenic PCBs primarily inhibit uroporphyrinogen decarboxylase, leading to a depletion of heme as a result of which synthesis of ALA synthetase increased.

  20. Suppression of Peroxisomal Enzyme Activities and Cytochrome P450 4A Isozyme Expression by Congeneric Polybrominated and Polychlorinated Biphenyls

    Directory of Open Access Journals (Sweden)

    Larry W. Robertson

    2007-09-01

    Full Text Available The purpose of this study was to determine the effects of PCBs and PBBs on peroxisome proliferator-activated receptor-α-(PPARα- associated enzyme activities or protein levels. Male Sprague-Dawley rats were administered a single IP injection (150 μmol/kg of either 3,3′,4,4′-tetrabromobiphenyl, 3,3′,4,4′-tetrachlorobiphenyl, 3,3′,5,5′-tetrabromobiphenyl, 2′,3,3′,4,5-pentachlorobiphenyl, 3,3′,4,4′,5-pentachlorobiphenyl, 2,2′,3,3′,5,5′-hexachlorobiphenyl, or 3,3′,4,4′,5,5′-hexabromobiphenyl in corn oil (10 ml/kg. One week later, the activities of catalase, peroxisomal fatty acyl-CoA oxidase, and peroxisomal beta-oxidation as well as cytochrome P450 4A (CYP4A protein content were determined in subcellular liver fractions. None of the peroxisomal enzyme activities were significantly increased by any of the halogenated biphenyl congeners tested. Except for minor (approx. 25% increases in the total CYP4A content following treatment with 2,2′,3,3′,5,5′-hexachlorobiphenyl and 3,3′,5,5′-tetrabromobiphenyl, CYP4A protein contents were not increased by any treatment. The two Ah receptor agonists, 3,3′,4,4′-tetrabromobiphenyl and 3,3′,4,4′,5-pentachlorobiphenyl, significantly diminished the liver content of CYP4A proteins and activities of the peroxisomal enzymes studied. Since a range of congeners with different biologic and toxicologic activities were selected for this study, it may be concluded that the polyhalogenated biphenyls do not induce peroxisome proliferation in the male rat, but rather certain members of this class of compounds down regulate peroxisome-associated enzymes. Since PCBs and PBBs do not increase

  1. Dry deposition of polychlorinated biphenyls in urban areas

    International Nuclear Information System (INIS)

    The PCB dry deposition flux was measured in Chicago with a greased, Mylar-covered smooth plate with a sharp leading edge pointed into the wind. The dry deposition flux of PCBs in Chicago averaged 3.8 μg/m2·day between May and November 1989 and 6.0 μg/m2·day for May and June 1990. A comparison of the PCB flux measured in Chicago to an estimated nonurban PCB flux shows that the flux of PCBs is up to 3 orders of magnitude higher in urban areas than in nonurban areas, indicating that Chicago and other urban areas near the Great Lakes must be considered as major source terms for deposition of PCBs into the lakes. The distribution of atmospheric PCBs between the gas and particle phase and the size distribution of particle-phase PCBs were also measured. The airborne PCB concentration as measured by the Noll rotary impactor (NRI) A stage (particles with aerodynamic diameters of > 6.5 μm) was higher in Chicago (0.94 ng/m3) than in Los Angeles (0.52 ng/m3), as was the mean particle-phase PCB concentration (47 vs 21 μg/g). PCBs were found to be associated with all sizes of atmospheric particles; however, their particle mass normalized concentration decreased with increasing particle size. PCBs associated with particles, particularly coarse particles, represented a significant fraction of the total PCB dry deposition flux even though PCBs in the ambient air were present primarily in the gas phase

  2. Arbuscular Mycorrhizal Fungal Hyphae Alter Soil Bacterial Community and Enhance Polychlorinated Biphenyls Dissipation

    Science.gov (United States)

    Qin, Hua; Brookes, Philip C.; Xu, Jianming

    2016-01-01

    We investigated the role of arbuscular mycorrhizal fungal (AMF) hyphae in alternation of soil microbial community and Aroclor 1242 dissipation. A two-compartment rhizobox system with double nylon meshes in the central was employed to exclude the influence of Cucurbita pepo L. root exudates on hyphal compartment soil. To assess the quantitative effect of AMF hyphae on soil microbial community, we separated the hyphal compartment soil into four horizontal layers from the central mesh to outer wall (e.g., L1–L4). Soil total PCBs dissipation rates ranged from 35.67% of L4 layer to 57.39% of L1 layer in AMF inoculated treatment, which were significant higher than the 17.31% of the control (P biphenyls as well as the total PCBs were significantly correlated with soil hyphal length (P biphenyl dissipation, while taxa from the Oxalobacteraceae and Streptomycetaceae responded negatively to AMF and PCB congener dissipation. Our results suggested that the AMF hyphal exudates as well as the hyphae per se did have quantitative effects on shaping soil microbial community, and could modify the PCBs dissipation processes consequently. PMID:27379068

  3. Polychlorinated biphenyls (PCBs) in a benthic ecosystem in Gwangyang Bay, South Korea

    International Nuclear Information System (INIS)

    Highlights: ► PCBs are still detectable in Gwangyang Bay in spite of their ban in 1980s. ► PCBs in the benthic ecosystem is enriched in lower chlorinated biphenyls. ► PCBs are released from a nearby local steel industry. ► Distribution of PCBs to the bay arises mostly from atmospheric transfer. - Abstract: Benthic ecosystem in Gwangyang Bay, a fast developing industrial area with steel production, port container handling, petroleum and other chemical processing in South Korea was studied. The average levels of polychlorinated biphenyls (ΣPCB) in the benthic components were: seawater 2.99 ± 0.13 (ng/L); sediment 294 ± 118 (ng/g TOC); [biota = ng/g lipid] starfish 92; prawn 131 ± 2; mussels 127 ± 22; crab 182 ± 114; clam 187; polychaeta 215; sea cucumber 497 ± 90; squill 603 ± 38; fish 396 ± 159. Levels in the inner bay samples were higher than the outer bay samples suggesting land based pollution. Good correlation (r2 = 0.79; p < 0.05) existed between PCB concentration and lipid content indicating partitioning processes in action. PCB signature in the abiotic and biotic components shows enrichment of lower chlorinated congeners emitted by a unique source nearby, viz. steel manufacturing plant.

  4. Polychlorinated biphenyls in surface soil in urban and background areas of Mongolia

    International Nuclear Information System (INIS)

    Polychlorinated biphenyls (PCBs) were measured in soil in some industrial towns (Ulaanbaatar, Suhbaatar, Erdenet, Darhan, Tsetserleg, Hovd, Ulaangom, Altay, Bayanhongor, Arvayheer, Saynshand, Choybalsan) and in background and rural areas of Mongolia. The average sum of all investigated PCB congeners in soil of Mongolia comes to 7.4 ng/g dry weight (DW) and varies from 0.53 ng/g DW till 114 ng/g DW. PCB levels in soil from towns are significantly higher than those in soil from background and rural areas. The PCB homological composition in soil sampled in highly-PCB-polluted sites is similar to the PCB homological pattern in Sovol and Aroclor 1254. Significant correlation between soil organic carbon and low chlorinated PCB both for towns and background sites was found. Significant differences in PCB means in soil in different natural zones were found. -- Highlights: •First study to measure PCBs in surface soil sampled throughout Mongolia. •The PCB patterns in polluted soil were similar to those in Sovol or Aroclor 1254. •Significant differences in PCB means in soil in different natural zones were found. -- Polychlorinated biphenyls were measured in soils throughout Mongolia

  5. Ab initio study of long-range electron transfer between biphenyl anion radical and naphthalene

    Institute of Scientific and Technical Information of China (English)

    李象远; 肖顺清; 何福城

    1999-01-01

    After the separation of the donor, the aeceptor, and the σ-type bridge from the π-σ-π system, the geometries of biphenyl, biphenyl anion radical, naphthalene, and naphthalene anion radical are optimized, and then the reorganization energy for the intermolecular electron transfer (ET) at the levels of HF/4-31G and HF/DZP is calculated. The ET matrix elements of the self-exchange reactions of the π-σ-π systems have been calculated by means of both the direct calculation based on the variational principle, and the transition energy between the molecular orbitals at the linear coordinate R=0.5. For the cross reactions, the ET matrix element and the geometry of the transition state are determined by searching the minimum energy splitting △min along the reaction coordinate. In the evaluation of the solvent reorganization energy of the ET in solution, the Marcus’ two-sphere model has been invoked. A few of ET rate constants for the intramolecular ET reactions for the π-σ-π systems, which contain

  6. Assessment of exposure risk of polychlorinated biphenyls to interior least terns (Sterna antillarum)

    Science.gov (United States)

    Sanchez, B.C.; Caldwell, C.A.

    2008-01-01

    Risk of polychlorinated biphenyl (PCB) exposure and effects were assessed for a colony of federally endangered interior least terns (Sterna antillarum) nesting on the Bitter Lake National Wildlife Refuge (NM, USA). The colony feeds from an area on the Refuge (Hunter Marsh/Oxbow Complex) wherein fish with elevated concentrations of total PCBs have been documented. Concentrations of total PCBs in whole fish averaged 0.94 mg/kg with a maximum concentration of 2.77 mg/kg, wet weight. Estimated daily PCB intake rates by adult birds throughout their 180-d breeding season ranged from <0.01 mg/kg/d to 0.98 mg/kg/d, yielding hazard quotients that ranged from 0.01 to 21.68. Polychlorinated biphenyls pose a moderate risk to the colony of interior least terns that breed at the Bitter Lake National Wildlife Refuge, but the exposure rate is not likely to threaten their overall breeding success. ?? 2008 SETAC.

  7. Atmospheric polychlorinated biphenyls in Indian cities: Levels, emission sources and toxicity equivalents

    International Nuclear Information System (INIS)

    Atmospheric concentration of Polychlorinated biphenyls (PCBs) were measured on diurnal basis by active air sampling during Dec 2006 to Feb 2007 in seven major cities from the northern (New Delhi and Agra), eastern (Kolkata), western (Mumbai and Goa) and southern (Chennai and Bangalore) parts of India. Average concentration of Σ25PCBs in the Indian atmosphere was 4460 (±2200) pg/m−3 with a dominance of congeners with 4–7 chlorine atoms. Model results (HYSPLIT, FLEXPART) indicate that the source areas are likely confined to local or regional proximity. Results from the FLEXPART model show that existing emission inventories cannot explain the high concentrations observed for PCB-28. Electronic waste, ship breaking activities and dumped solid waste are attributed as the possible sources of PCBs in India. Σ25PCB concentrations for each city showed significant linear correlation with Toxicity equivalence (TEQ) and Neurotoxic equivalence (NEQ) values. Highlights: •Unlike decreasing trend of PCBs in United States and European countries, high levels of PCBs remain in the Indian atmosphere. •Existing emission inventories cannot explain the high PCB concentrations in Indian atmosphere. •Electronic waste recycling, ship dismantling and open burning of municipal solid waste are implicated as potential sources. -- Measurement of atmospheric Polychlorinated biphenyls in seven major Indian cities

  8. Hydroxy and methylsulfone metabolites of polychlorinated biphenyls in the human blood and tissues

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Yoshito; Haraguchi, Koichi [Daiichi College of Pharmaceutical Sciences, Fukuoka (Japan)

    2004-09-15

    Polychlorinated biphenyls (PCBs) are a group of chlorinated compounds which have polluted the global environment, persistently retained in wildlife and humans, and eventually affected the human health. PCBs are biotransformed to mainly hydroxy (HO-) and methylsulfone (MeSO{sub 2}-) metabolites in the animal and human tissues. About ten thousands of chemical and biological researches on PCBs, HOPCBs and MeSO{sub 2}-PCBs have been reported and reviewed so far. Letcher et al. cleverly reviewed the HO-PCBs and MeSO2-PCBs in 2000. We review the contamination of HO-PCBs and MeSO{sub 2}-PCBs in human tissues and their possible effects to human health. Different positional numberings of Cl-, HO- and MeSO{sub 2}- on biphenyl rings were used by different authors. Then, nomenclature of PCB metabolite was assessed by Maervoet et al. and they suggested to use the IUPAC chemical name and number of parent PCB congener with the subsequent assignment of the phenyl ring position number of the HO- or MeSO{sub 2}- substituent number afterward.

  9. Thermophysical properties of (diphenyl ether + biphenyl) mixtures for their use as heat transfer fluids

    International Nuclear Information System (INIS)

    Highlights: ► Densities at high pressure of mixtures of diphenyl ether and biphenyl were reported. ► The composition dependence on thermal conductivity and viscosity is very smooth. ► Crossing point in αp isotherms were detected around 38 MPa. ► MYEGA reproduces our experimental η(T) curves with deviations lower than 0.24%. ► The experimental devices were checked obtaining good agreements with literature. - Abstract: Experimental measurements of density, viscosity and thermal conductivity are reported for pure diphenyl ether and three different binary mixtures of diphenyl ether and biphenyl including the eutectic point. Density has been measured for the liquid phase at temperatures ranging from (298.15 to 363.15) K and for pressures up to 45 MPa using a high-pressure vibrating tube densimeter. A Tammann–Tait correlation of the experimental densities has been proposed for each composition. From these correlations, isothermal compressibility, isobaric thermal expansivity and internal pressure have been determined. Moreover, viscosity and thermal conductivity were experimentally determined at atmospheric pressure for several temperatures by using a rolling ball viscometer and a device based in the hot-wire technique, respectively. All the experimental devices used to determine the thermophysical properties were checked finding good agreements with previous literature data. The experimental viscosity values were correlated using the Vogel–Fulcher–Tammann, Avramov–Milchev and MYEGA equation.

  10. Transcriptional Response of Rhodococcus aetherivorans I24 to Polychlorinated Biphenyl-Contaminated Sediments

    KAUST Repository

    Puglisi, Edoardo

    2010-04-06

    We used a microarray targeting 3,524 genes to assess the transcriptional response of the actinomycete Rhodococcus aetherivorans I24 in minimal medium supplemented with various substrates (e. g., PCBs) and in both PCB-contaminated and non-contaminated sediment slurries. Relative to the reference condition (minimal medium supplemented with glucose), 408 genes were upregulated in the various treatments. In medium and in sediment, PCBs elicited the upregulation of a common set of 100 genes, including gene-encoding chaperones (groEL), a superoxide dismutase (sodA), alkyl hydroperoxide reductase protein C (ahpC), and a catalase/peroxidase (katG). Analysis of the R. aetherivorans I24 genome sequence identified orthologs of many of the genes in the canonical biphenyl pathway, but very few of these genes were upregulated in response to PCBs or biphenyl. This study is one of the first to use microarrays to assess the transcriptional response of a soil bacterium to a pollutant under conditions that more closely resemble the natural environment. Our results indicate that the transcriptional response of R. aetherivorans I24 to PCBs, in both medium and sediment, is primarily directed towards reducing oxidative stress, rather than catabolism. © 2010 Springer Science+Business Media, LLC.

  11. The proton nuclear magnetic shielding tensors in biphenyl: experiment and theory.

    Science.gov (United States)

    Schönborn, Frank; Schmitt, Heike; Zimmermann, Herbert; Haeberlen, Ulrich; Corminboeuf, Clémence; Grossmann, Gisbert; Heine, Thomas

    2005-07-01

    Line-narrowing multiple pulse techniques are applied to a spherical sample crystal of biphenyl. The 10 different proton shielding tensors in this compound are determined. The accuracy level for the tensor components is 0.3 ppm. The assignment of the measured tensors to the corresponding proton sites is given careful attention. Intermolecular shielding contributions are calculated by the induced magnetic point dipole model with empirical atom and bond susceptibilities (distant neighbours) and by a new quantum chemical method (near neighbours). Subtracting the intermolecular contributions from the (correctly assigned) measured shielding tensors leads to isolated-molecule shielding tensors for which there are symmetry relations. Compliance to these relations is the criterion for the correct assignment. The success of this program indicates that intermolecular proton shielding contributions can be calculated to better than 0.5 ppm. The isolated-molecule shielding tensors obtained from experiment and calculated intermolecular contributions are compared with isolated-molecule quantum chemical results. Expressed in the icosahedral tensor representation, the rms differences of the respective tensor components are below 0.5 ppm for all proton sites in biphenyl. In the isolated molecule, the least shielded direction of all protons is the perpendicular to the molecular plane. For the para proton, the intermediate principal direction is along the C-H bond. It is argued that these relations also hold for the protons in the isolated benzene molecule. PMID:15949748

  12. Assessing atmospheric concentration of polychlorinated biphenyls by evergreen Rhododendron maximum next to a contaminated stream.

    Science.gov (United States)

    Dang, Viet D; Walters, David M; Lee, Cindy M

    2016-09-01

    Conifers are often used as an air passive sampler, but few studies have focused on the implication of broadleaf evergreens to monitor atmospheric semivolatile organic compounds such as polychlorinated biphenyls (PCBs). In the present study, the authors used Rhododendron maximum (rhododendron) growing next to a contaminated stream to assess atmospheric PCB concentrations. The present study area was located in a rural setting and approximately 2 km downstream of a former capacitor plant. Leaves from the same mature shrubs were collected in late fall 2010 and winter and spring 2011. Polychlorinated biphenyls were detected in the collected leaves, suggesting that rhododendron can be used as air passive samplers in rural areas where active sampling is impractical. Estimated ΣPCB (47 congeners) concentrations in the atmosphere decreased from fall 2010 to spring 2011 with concentration means at 3990 pg m(-3) , 2850 pg m(-3) , and 931 pg m(-3) in fall 2010, winter 2011, and spring 2011, respectively. These results indicate that the atmospheric concentrations at this location continue to be high despite termination of active discharge from the former industrial source. Leaves had a consistent pattern of high concentrations of tetra-CBs and penta-CBs similar to the congener distribution in polyethylene passive samplers deployed in the water column, suggesting that volatilized PCBs from the stream were the primary source of contaminants in rhododendron leaves. Environ Toxicol Chem 2016;35:2192-2198. © 2016 SETAC. PMID:26889751

  13. Syntheses,Crystal Structures and Fluorescence Properties of Two Triazolyl Derivatives with Biphenyl Links

    Institute of Scientific and Technical Information of China (English)

    LING Yun; LI Jing; HU Ai-Xi; ZHANG Lei

    2009-01-01

    Two novel triazolyl derivatives with biphenyl links,namely 4,4-bis(1,2,4-triazol-1-yl-methyl)biphenylene 1 and 4,4-bis(3,5-dimethyl-1,2,4-triazol-1-ylmethyl)biphenylene 2,have been synthesized and structurally characterized by single-crystal X-ray diffraction.Compounds 1·H2O·HCl and 2·2H2O·2HCl crystallize in the monoclinic system with spacegroup C2/c and P21/c,respectively.he dihedral angles of the two phenyl rings are 30.26(6)° in 1·H2O·HCl,while co-planar(0.00(7)°)in 2·2H2O·2HCl.In 1'H2O·HCl,the N-H…O hydrogen bonds link 1 to form chain-like structures which are further connected by O-H…Cl,C-H…Cl,C-H…O and π-π supramolecular interactions.The hydrogen bonds of O-H…Cl in 2·2H2O·2HCl provide distinguishing P/M helical chains along the baxis,and these chains are further connected by N-H…O hydrogen bonds to generate a 2D structure.Compounds 1 and 2 in methanol solution show much stronger emission bands at 319 nm than biphenyl at 3 16 nm under excitation at 260 nm.

  14. The biopsychosocial model of stress in adolescence: self-awareness of performance versus stress reactivity

    OpenAIRE

    Rith-Najarian, Leslie R.; McLaughlin, Katie A.; Sheridan, Margaret A.; Nock, Matthew K.

    2014-01-01

    Extensive research among adults supports the biopsychosocial (BPS) model of challenge and threat, which describes relationships among stress appraisals, physiological stress reactivity, and performance; however, no previous studies have examined these relationships in adolescents. Perceptions of stressors as well as physiological reactivity to stress increase during adolescence, highlighting the importance of understanding the relationships among stress appraisals, physiological reactivity, a...

  15. Dynamics of polychlorinated biphenyls in striped bass from the Hudson river. III. tissue disposition and routes for elimination

    International Nuclear Information System (INIS)

    Striped bass were exposed to 14C-polychlorinated biphenyls (PCB) in single-dose and multiple-dose experiments. Samples were analyzed to determine rate constants for PCB elimination from individual tissues, PCB concentration in tissues, the proportion of the PCB burden retained and the proportion of the cumulative dose retained by each tissue at various times after exposure. An experiment was also conducted to determine both the potential for secondary PCB uptake in dietary exposure studies and the relative tissue disposition of PCBs assimilated from dietary sources as compared to direct water uptake. PCBs were present in the tissues of striped bass within 6 h after administration of a single dose. Certain tissue compartments, such as the liver/gall bladder, accumulated PCBs over a period of 48 h even though the whole-body burden had decreased between 24 and 48 h. Except for the gills, elimination rate constants for all tissues were similar and were to the whole body elimination rate constant. Elimination during the first few hours following exposure to PCBs may be due to equilibrium partitioning from the gill to the environment. The multiple-dose study showed that PCB burdens in striped bass continued to increase with dosing. However, tissue-specific rate constants for PCB elimination led to an increased flux of PCB out of tissues, and an overall decline in the percent of the cumulative dose remaining in the body 48 h after administration of each dose. The most likely route for PCB elimination from striped bass was from tissues to the liver and thence to the intestine via the bile. These were no differences in the tissue disposition of PCB related to route of exposure

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

    International Nuclear Information System (INIS)

    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.

  17. Transfer and distribution of accumulated (/sup 14/C)polychlorinated biphenyls from maternal to fetal and suckling rats

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Y.; Aburada, S.; Hashimoto, K.; Kitaura, T.

    1986-11-01

    (/sup 14/C)polychlorinated biphenyls (PCBs (KC-600)) were administered orally to female rats at the dose of 10 mg/kg in olive oil once a week for five weeks. Four weeks after the last administration of (/sup 14/C)PCBs, they were mated with untreated males. The distribution of total /sup 14/C was examined in maternal and offspring tissues. The average amount of PCB accumulated in dams was 44.2% of the dose two weeks after the last administration. The average amount transferred from dam to fetus was 0.003% accumulated in the dam. In the fetus, the highest concentration was found in the fetal placenta followed by the liver, heart, skin, muscle, blood, lung, and brain. The PCBs level in fetal blood was the same as in maternal blood. The average concentration of PCBs in milk was 1.84 ppm. The amount transferred to sucklings increased gradually to about 5% of the maternal PCBs. In suckling rats, PCBs were distributed at the highest concentration in adipose tissues and at intermediate concentrations in the skin, adrenal gland, and liver. The liver to body weight ratio of offspring was significantly increased on the 11th and 25th days after birth. The nursing rats had lower PCBs concentrations compared with the pregnant and virgin rats. The organ concentrations of PCBs in dam and offspring were about ten times as high as those found after treatment with Kanechlor-400. These results may suggest that PCBs with higher chlorine content remained in tissues for a longer period of time.

  18. Evidence of elevated levels of polychlorinated biphenyl congeners in commonly consumed fish from Eleyele Reservoir, Southwestern Nigeria.

    Science.gov (United States)

    Adeogun, Aina O; Adedara, Isaac A; Farombi, Ebenezer O

    2016-01-01

    Environmental pollution of water, which is a source of cheap and affordable protein in the form of fish on which the population depends on, is of great concern globally. The present study assesses the levels of polychlorinated biphenyls (PCBs) congeners in sediments and six commonly consumed cichlid species from Eleyele Reservoir, Southwestern Nigeria. The results indicate that the concentrations of heavier PCB congeners are higher than the lighter congeners in both sediment and fish tissue. The predominant PCB congeners in the sediment samples from this site were PCBs 8, 44, 114, 101, 189, 196, 206 and 209. The concentration of PCB congeners increased with increasing molecular weight from hepta-PCB to deca-PCB in all fish species. The trend in accumulation of total PCBs in fish was as follows: Tilapia guineensis (2,531.1 ± 74.6 ng/g) > Sarotherodon galilaeus (1178.7 ± 68.5 ng/g) > Oreochromis niloticus > (891.8 ± 49.6 ng/g) > Tilapia zillii (832.8 ± 38.2 ng/g) > Hemichromis fasciatus (475.7 ± 28.5 ng/g) > Sarotherodon melanotheron (333.2 ± 26.1 ng/g). In summary, data from this study shows that the levels of PCBs in cichlid species from Eleyele Reservoir are higher than the threshold level of 0.023-0.047 ng g(-1) recommended by United States Environmental Protection Agency. Such elevated PCB levels present significant health implications for human consumers and a threat to the resident fish communities. PMID:23859942

  19. Generation of Localized Surface Plasmon Resonance Using Hybrid Au–Ag Nanoparticle Arrays as a Sensor of Polychlorinated Biphenyls Detection

    Directory of Open Access Journals (Sweden)

    Jing Liu

    2016-08-01

    Full Text Available In this study, the hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate periodic nanoparticle arrays (PNAs were designed to investigate their extinction spectra of the localized surface plasmon resonances (LSPRs. First, their simulating extinction spectra were calculated by discrete dipole approximation (DDA numerical method by changing the media refractive index. Simulation results showed that as the media refractive index was changed from 1.0 to 1.2, the maximum peak intensity of LSPRs spectra had no apparent change and the wavelength to reveal the maximum peak intensity of LSPRs spectra was shifted lower value. Polystyrene (PS nanospheres with two differently arranged structures were used as the templates to deposit the hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate periodic PNAs by evaporation method. The hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate PNAs were grown on single crystal silicon (c-Si substrates, and their measured extinction spectra were compared with the calculated results. Finally, the fabricated hexagonal lattices of triangular PNAs were investigated as a sensor of polychlorinated biphenyl solution (PCB-77 by observing the wavelength to reveal the maximum extinction efficiency (λmax. We show that the adhesion of β-cyclodextrins (SH-β-CD on the hybrid Au–Ag hexagonal lattice of triangular PNAs could be used to increase the variation of λmax. We also demonstrate that the adhesion of SH-β-CD increases the sensitivity and detection effect of PCB-77 in hexagonal lattice of triangular PNAs.

  20. POLYCHLORINATED BIPHENYL COMPLIANCE ISSUES IN THE 21ST CENTURY: POORLY RECOGNIZED AND POTENTIALLY DEVASTATING-8162

    International Nuclear Information System (INIS)

    Thirty-one years have passed since the United States Congress passed the Toxic Substances Control Act (TSCA) [1]. The 1976 law essentially eliminated future production of polychlorinated biphenyls (PCBs) within the United States and greatly limited the use of previously manufactured PCBs and PCB products. The ultimate objective of the law was the complete elimination of these chemicals due to concerns about their potentially toxic effects on health and the environment. PCBs were manufactured in the United States between 1929 and 1977. They were highly valued for their fire and heat-resistance properties and for their chemical stability. As a result, PCBs were used in a variety of thermally and/or chemically stressful applications. They did not conduct electricity and therefore were particularly well-suited for use as insulating fluids in high-voltage electric equipment. PCBs were also used in various other applications, such as in hydraulic and heat transfer fluids. Strict controls on the use and disposal of PCBs were imposed by the TSCA implementing regulations at 40 CFR 761 [2]. As a result, most heavy users of PCB products worked hard to curtail their PCB use. Many organizations that once used substantial amounts of PCBs, subsequently declared themselves ''PCB free''. Unfortunately, in many cases, these ''PCB-free'' declarations were premature, as PCBs were used in many more applications than insulating fluids. From the 1990s and to the present day, PCBs increasingly have been discovered in non-liquid forms. These materials were used or installed in facilities constructed before the 1979 ''PCB ban''. Examples include applied paints and coatings, caulking, pre-formed joint filler, and plastic or rubber wire and cable insulation. Proper identification of these materials is necessary for appropriate and compliant waste management during decommissioning and deactivation (D and D) activities. PCBs can pose other significant waste management issues for D and D