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11.
Dr Martina Mackova Ludmila Chroma Petra Kucerova Jiri Burkhard Katerina Demnerova Tomas Macek 《International journal of phytoremediation》2001,3(4):401-414
Transformation of polychlorinated biphenyls was studied using different strains of in vitro cultured cells of horseradish (Armoracia rusticana L.). Time and concentration dependence of this process and production of intracellular and extracellular peroxidases were measured with differentiated shooty teratoma culture K54. The yield of PCB transformation and the viability of the cells were highly dependent on PCB concentration. 100 ppm PCB totally inhibited growth of the cells, and reduced their metabolism of xenobiotics. Experiments with a peroxidase (POX) inhibitor, propylgallate, and a cytochrome P450 inhibitor, aminobenztriazole, indicated the involvement of both enzymatic systems in PCB metabolism. 相似文献
12.
The objective of this study was to investigate the effects of mycorrhizal infection on vegetative uptake of polychlorinated biphenyls. Feltleaf willow (Salix alaxensis) and balsam poplar (Populus balsamifera) were grown in soil spiked with 6 mg/kg 3,3′,4,4′-tetrachlorobiphenyl-(UL-14C). The fungicide Daconil2787® was employed to suppress indigenous mycorrhizal infection. After 100 days of greenhouse incubation in semienclosed phytoreactors, mycorrhizal infection was found to be approximately threefold higher in the untreated willows vs. the fungicide-amended willows. Radio-label uptake was found to correlate most highly with mycorrhizal infection in the willow roots (R = 0.83). Over the same time period, mycorrhizal infection in the poplars was not significantly affected by fungicide addition. In the poplar phytoreactors, radiolabel uptake was most highly correlated with water use (R = 0.70). The overall vegetative radiolabel uptake was low (≈ 1%), but the limited uptake was attributed to soil sorption processes rather than vegetative limitations. 相似文献
13.
Zusammenfassung Insgesamt wurden 60 Resteier des Rotmilans in drei Untersuchungsgebieten im südlichen Teil des Bundeslandes Sachsen-Anhalt zwischen 1987–1993 gesammelt und auf elf persistente Chlorkohlenwasserstoff-Verbindungen und Quecksilber sowie z. T. auf radioaktive Nuklide untersucht:
1. | Die Eiproben waren hauptsächlich mit p,p'-DDE, PCB 138, 153 und 180 sowie Hg belastet, jedoch auf einem für die Reproduktion unbedenklichem Niveau. |
2. | Proben aus Industrie- und Großstadtnähe waren signifikant höher mit den Industrieabprodukten HCB, -HCH und höherchlorierten PCBs kontaminiert. Proben aus landwirtschaftlich intensiv genutzten Gebieten enthielten mehr p,p'-DDT. p,p'-DDE, Hg und -HCH zeigten keine signifikanten Unterschiede in ihrer räumlichen Verteilung. |
3. | Da die Spitzenwerte der einzelnen Verbindungen in verschiedenen Jahren auftreten, sind die Trends unterschiedlich und zeigen Abnahmen über den gesamten Untersuchungszeitraum hinweg (PCB 52), Abnahmen erst ab 1990/91 (HCB, - und -HCH, Hg) bzw. Anstiege nach vorangegangenem Kontaminationsrückgang (höherchlorierte PCB, p,p'-DDE). Mögliche Ursachen werden diskutiert. |
4. | Die Untersuchung von vier Eiinhalten von 1988 auf radioaktive Nuklide (Cäsium-Isotope) verlief negativ. |
Persistent organochlorine compounds, mercury and radionuclids in eggs of Red Kite (Milvus milvus) from Saxony-Anhalt (Germany)
Summary Sixty infertile Red Kite eggs were collected in three regions in the southern part of the federal state of Saxony-Anhalt. Their contents were tested for eleven chlorinated hydrocarbons, mercury and partly for radionuclids (radiocesium):相似文献
1. The egg samples on average contained p,p'-DDE, PCB 138, PCB 153, PCB 180 and Hg in low concentrations. 2. The samples from an industrial and urban region contained significantly more HCB, -HCH and high chlorinated PCBs. The contamination of p,p'-DDT was on a higher level in eggs from farmed areas. 3. The trends of the chemicals were different between 1987 and 1993. PCB 52 shows a significant decrease in this time and HCB, - und -HCH, Hg only since 1990/91. p,p'-DDE, PCB 138, PCB 153 and PCB 180 increased up to 1992, after contamination decreased. Possible reasons are discussed. 4. The contents of four eggs from 1988 did not include radiocesium.
14.
To investigate the occurrences of polychlorinated biphenyls (PCBs) in suburban vegetable soils of Changchun area, Northeast China, 106 urban vegetable soil samples were collected from Changchun City, Nongan County, Dehui City, Yushu City, Jiutai City, Shuangyang District. We analyzed the concentrations, compositions and sources of 7 PCBs in top soils of Changchun area, and evaluated the non-carcinogenic and carcinogenic risk of PCBs pollution to exposed population. The total concentrations of 7 PCBs ranged from 1.31 to 148 ng/g dry weight (dw) with a mean value of 42.0 ng/g and dominated by Hepta-CBs and Penta-CBs. Principal component analysis (PCA) revealed that PCB pollution in soils of Changchun area mainly related to transportation, vehicle emissions, paints and other industries. Human health risk assessment showed that the cumulative non-carcinogenic and the cumulative carcinogenic risk in children and adults in the industrial land and residential land were acceptable, considering only 7 PCBs homologues were analyzed in this study, the actual risk could be higher. 相似文献
15.
Hydroxylated polychlorinated biphenyls are the metabolites produced from parent compounds by the drug-metabolizing enzyme cytochrome P450. These compounds are suspected to disrupt postembryonic neural development in the brains of mammals including humans. We studied the effects of these compounds on thyroid hormone function in the brain by using metamorphosing tadpoles of the African clawed toad (Xenopus laevis) as a model for mammalian postembryonic development. The metamorphosis assay revealed that these compounds inhibit thyroid hormone-induced metamorphosis. Genome-wide gene expression analysis in the brain following short-term exposure demonstrated that delayed metamorphosis could partially be caused by disruption of thyroid hormone-induced gene expression. Furthermore, we associated the terms of functional ontology with the genes, whose expression was disrupted by these compounds. We suggest that the use of a genome-wide analysis coupled with bioinformatics might provide an overview of the molecular mechanism underlying thyroid-disrupting activities in vivo. 相似文献
16.
Polybrominated diphenyl ethers (PBDEs) are widely used as additive flame-retardants and have been detected in human blood,
adipose tissue, and breast milk. Developmental and long-term exposures to these chemicals may pose a human health risk, especially
to children. We have previously demonstrated that polychlorinated biphenyls (PCBs), which are structurally similar to PBDEs
and cause neurotoxicity, perturb intracellular signaling events including calcium homeostasis and protein kinase C translocation,
which are critical for neuronal function and development of the nervous system. The objective of the present study was to
test whether environmentally relevant PBDE congeners 47 and 99 are also capable of disrupting Ca2 + homeostasis. Calcium buffering was determined by measuring 45Ca2 + -uptake by microsomes and mitochondria, isolated from adult male rat brain (frontal cortex, cerebellum, hippocampus, and hypothalamus).
Results show that PBDEs 47 and 99 inhibit both microsomal and mitochondrial 45Ca2 + -uptake in a concentration-dependent manner. The effect of these congeners on 45Ca2 + -uptake is similar in all four brain regions though the hypothalamus seems to be slightly more sensitive. Among the two preparations,
the congeners inhibited 45Ca2 + -uptake in mitochondria to a greater extent than in microsomes. These results indicate that PBDE 47 and PBDE 99 congeners
perturb calcium signaling in rat brain in a manner similar to PCB congeners, suggesting a common mode of action of these persistent
organic pollutants.
The research described in this article has been reviewed by the National Health and Environmental Effects Research Laboratory
of the US Environmental Protection Agency, and approved for publication. Approval does not signify that the contents necessarily
reflect the views and policies of the Agency nor does mention of trade names or commercial products constitute endorsement
or recommendation for use.
These results will be presented at the 21th Biennial Meeting of International Society for Neurochemistry and American Society
for Neurochemistry in Cancun, Mexico (August 19–24, 2007).
Special issue article in honor of Dr. Frode Fonnum. 相似文献
17.
D. O. Rybkina E. G. Plotnikova L. V. Dorofeeva Yu. L. Mironenko V. A. Demakov 《Microbiology》2003,72(6):672-677
Strain B51 capable of degrading polychlorinated biphenyls (PCB) was isolated from soil contaminated with wastes from the chemical industry. Based on its morphological and chemotaxonomic characteristics, the strain was identified as a Microbacterium sp. Experiments with washed cells showed that strain B51 is able to degrade ortho- and para-substituted mono-, di-, and trichlorinated biphenyls (MCB, DCB, and TCB, respectively). Unlike the known PCB degraders, Microbacterium sp. B51 is able to oxidize the ortho-chlorinated ring of 2,2-DCB and 2,4-DCB and the para-chlorinated ring of 4.4-DCB. The degradation of 2,4-DCB and 4,4-DCB was associated with the accumulation of 4-chlorobenzoic acid (4-CBA) in the medium in amounts comprising 80–90% of the theoretical yield. The strain was able to utilize 2-MCB, 2,2-DCB, and their intermediate 2-CBA and to oxidize the mono(ortho)-chlorinated ring of 2,4,2-TCB and the di(ortho-para)-chlorinated ring of 2,4,4-TCB. A mixed culture of Microbacterium sp. B51 and the 4-CBA-degrading bacterium Arthrobacter sp. H5 was found to grow well on 1 g/l 2,4-DCB as the sole source of carbon and energy. 相似文献
18.
Prolactin modifies the prostaglandin synthesis, prolactin binding and fluidity of mouse liver membranes 总被引:1,自引:0,他引:1
J R Dave N V Brown R A Knazek 《Biochemical and biophysical research communications》1982,108(1):193-199
The objective of these studies was to determine if prolactin, known to induce its own receptors, alters the prostaglandin (PG) synthesis which could, in turn, modify the fluidity of the membrane and thus alter the functionality of prolactin receptors. Adult male C3H mice were injected subcutaneously with 100 μg of oPRL every 4 h for 0, 24 or 48 h and sacrificed 8 h after receiving the last injection. Liver 100,000 × membrane pellets were used in the measurement of these parameters. The amount of binding of prolactin to these membranes increased with the duration of injections, the values being 179 and 244% of control values after 24 and 48 h of injections, respectively. The amounts of PGF2α and PGE synthesized also increased after these injections, the values being 127 and 270% of control for PGF2α and 634 and 695% of control values for PGE after 24 and 48 h of injections, respectively. Fluorescence polarization, an index of microviscosity, was decreased by 14 and 20% after 24 and 48 h of PRL administration, respectively. Previous studies have demonstrated simultaneous in vitro effects of prostaglandin on both prolactin receptors and membrane fluidity. The current data are in agreement with those observations and suggest that prolactin may modulate its own receptor by increasing the fluidity of the membrane in which it exists by alterations within the PG cascade. Such biochemical changes may then modify existing restraints and allow the hormone receptor to assume a more functional configuration. 相似文献
19.
L W Robertson A Parkinson S Safe 《Biochemical and biophysical research communications》1980,92(1):175-182
The synthesis and purification of a component of fireMaster BP-6 and fireMaster FF-1, 2,3′,4,4′,5-pentabromobiphenyl, is described. The compound was found to be a potent inducer of liver microsomal drug-metabolizing enzymes in the rat, enhancing those enzymic activities induced by both phenobarbitone and 3-methylcholanthrene (i.e. cytochromes P-450 and P-448). The pentabromobiphenyl enhanced the activities of benzo[a]pyrene hydroxylase, dimethylamino-antipyrine N-demethylase and NADPH-cytochrome c reductase. The hepatic cytochromes b5 and P-450 were increased and the Soret peak maximum of the latter was shifted to 448.5 nm. The relative peak intensities and spectral shifts for the ethylisocyanide-binding difference spectra confirmed the mixed induction characteristics of 2,3′,4,4′,5-pentabromobiphenyl. 相似文献
20.
The role of metabolic activation in the binding of polychlorinated biphenyls (PCBs) to cellular macromolecules was investigated in vivo by comparing the relative binding of 2,4,5,2′,4′,5′-[U-14C]hexachlorobiphenyl (2,4,5), a slowly metabolized PCB, with that of 2,3,6,2′,3′,6′-[U-14C]hexachlorobiphenyl (2,3,6), a rapidly metabolized PCB, and the appropriate controls. Each hexachlorobiphenyl was administered to mice, orally for 5 days (7.28 mg/kg/day). Following the dosing schedule, animals were killed at 1, 5 and 8 days. The concentration of each PCB was determined in liver, muscle and kidney and in purified macromolecules isolated from those tissues. The concentration of 2,4,5 was consistently higher than the concentration of 2,3,6 in all tissues studied. However, the amount of 2,3,6 bound to the purified macromolecules was consistently at least one order of magnitude greater than that of 2,4,5. The greatest binding was observed in RNA followed by protein and DNA, respectively. The purity of the macromolecules and the presence of PCB-derived radioactivity at the monomer level were confirmed. This is the first report of 14C-labeled PCB being bound to purified RNA, DNA, and proteins isolated from the tissues of animals treated in vivo. The binding is thought to be covalent and to be the result of metabolic activation. 相似文献