Pentachlorophenol (PCP) is a toxic and persistent wood and cellulose preservative extensively used in the past decades. The production process of PCP generates polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) as micropollutants. PCDD/Fs are also known to be very persistent and dangerous for human health and ecosystem functioning. Several physico-chemical and biological technologies have been used to remove PCP and PCDD/Fs from the environment. Bacterial degradation appears to be a cost-effective way of removing these contaminants from soil while causing little impact on the environment. Several bacteria that cometabolize or use these pollutants as their sole source of carbon have been isolated and characterized. This review summarizes current knowledge on the metabolic pathways of bacterial degradation of PCP and PCDD/Fs. PCP can be successfully degraded aerobically or anaerobically by bacteria. Highly chlorinated PCDD/Fs are more likely to be reductively dechlorinated, while less chlorinated PCDD/Fs are more prone to aerobic degradation. The biochemical and genetic basis of these pollutants' degradation is also described. There are several documented studies of effective applications of bioremediation techniques for the removal of PCP and PCDD/Fs from soil and sediments. These findings suggest that biodegradation can occur and be applied to treat these contaminants.

• Klíčová slova
• bacterial degradation, bioremediation, contaminated soil, pentachlorophenol, polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, wood preservation,
• MeSH
• Bacteria metabolismus   MeSH
• benzofurany analýza   metabolismus   MeSH
• biodegradace * MeSH
• biotransformace MeSH
• látky znečišťující půdu analýza   metabolismus   MeSH
• lidé MeSH
• pentachlorfenol metabolismus   MeSH
• polychlorované dibenzodioxiny metabolismus   MeSH
• půda chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• benzofurany MeSH
• látky znečišťující půdu MeSH
• pentachlorfenol MeSH
• polychlorované dibenzodioxiny MeSH
• půda MeSH

Using pine needles as a bio-sampler of atmospheric contamination is a relatively cheap and easy method, particularly for remote sites. Therefore, pine needles have been used to monitor a range of semi-volatile contaminants in the air. In the present study, pine needles were used to monitor polychlorinated biphenyls (PCBs) in the air at sites with different land use types in Sweden (SW), Czech Republic (CZ), and Slovakia (SK). Spatiotemporal patterns in levels and congener profiles were investigated. Multivariate analysis was used to aid source identification. A comparison was also made between the profile of indicator PCBs (ind-PCBs-PCBs 28, 52, 101, 138, 153, and 180) in pine needles and those in active and passive air samplers. Concentrations in pine needles were 220-5100 ng kg(-1) (∑18PCBs - ind-PCBs and dioxin-like PCBs (dl-PCBs)) and 0.045-1.7 ng toxic equivalent (TEQ) kg(-1) (dry weight (dw)). Thermal sources (e.g., waste incineration) were identified as important sources of PCBs in pine needles. Comparison of profiles in pine needles to active and passive air samplers showed a lesser contribution of lower molecular weight PCBs 28 and 52, as well as a greater contribution of higher molecular weight PCBs (e.g., 180) in pine needles. The dissimilarities in congener profiles were attributed to faster degradation of lower chlorinated congeners from the leaf surface or metabolism by the plant.

• Klíčová slova
• Active and passive samplers, Atmospheric pollution, Bio-sampler, Europe, Pine needle, Polychlorinated biphenyls, Sources, Spatial and temporal distribution,
• MeSH
• borovice lesní chemie   metabolismus   MeSH
• dioxiny chemie   metabolismus   MeSH
• listy rostlin chemie   MeSH
• monitorování životního prostředí metody   MeSH
• polychlorované bifenyly chemie   metabolismus   MeSH
• polychlorované dibenzodioxiny chemie   metabolismus   MeSH
• spalování odpadů MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa MeSH
• Názvy látek
• dioxiny MeSH
• polychlorované bifenyly MeSH
• polychlorované dibenzodioxiny MeSH

Despite the growing concern over the potential biological impact of nanoparticles (NPs) in the aquatic environment, little is known about their interactions with other pollutants. The bivalve Mytilus sp, largely utilized as a sentinel for marine contamination, has been shown to represent a significant target for different types of NP, including n-TiO2, one of the most widespread in use. In this work, the possible interactive effects of n-TiO2 and 2,3,7,8-TCDD, chosen as models of NP and organic contaminant, respectively, were investigated in Mytilus galloprovincialis. In vitro experiments with n-TiO2 and TCDD, alone and in combination, were carried out in different conditions (concentrations and times of exposure), depending on the target (hemocytes, gill cells and biopsies) and the endpoint measured. Mussels were also exposed in vivo to n-TiO2 (100 μg L(-1)) or to TCDD (0.25 μg L(-1)), alone and in combination, for 96 h. A wide range of biomarkers, from molecular to tissue level, were measured: lysosomal membrane stability and phagocytosis in hemocytes, ATP-binding cassette efflux transporters in gills (gene transcription and efflux activity), several biomarkers of genotoxicity in gill and digestive cells (DNA damage, random amplified polymorphic DNA-RAPD changes), lysosomal biomarkers and transcription of selected genes in the digestive gland. The results demonstrate that n-TiO2 and TCDD can exert synergistic or antagonistic effects, depending on experimental condition, cell/tissue and type of measured response. Some of these interactions may result from a significant increase in TCDD accumulation in whole mussel organisms in the presence of n-TiO2, indicating a Trojan horse effect. The results represent the most extensive data obtained so far on the sub-lethal effects of NPs and organic contaminants in aquatic organisms. Moreover, these data extend the knowledge on the molecular and cellular targets of NPs in bivalves.

• Klíčová slova
• Biomarker, Dioxin, Mytilus galloprovincialis, Nanoparticles, Titanium dioxide,
• MeSH
• biologické markery analýza   MeSH
• chemické látky znečišťující vodu metabolismus   toxicita   MeSH
• fagocytóza účinky léků   MeSH
• hemocyty účinky léků   MeSH
• lékové interakce MeSH
• lyzozomy účinky léků   MeSH
• Mytilus účinky léků   genetika   metabolismus   MeSH
• nanočástice toxicita   MeSH
• polychlorované dibenzodioxiny metabolismus   toxicita   MeSH
• poškození DNA účinky léků   MeSH
• technika náhodné amplifikace polymorfní DNA MeSH
• titan toxicita   MeSH
• žábry účinky léků   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biologické markery MeSH
• chemické látky znečišťující vodu MeSH
• polychlorované dibenzodioxiny MeSH
• titan MeSH
• titanium dioxide MeSH Prohlížeč

Levels of polychlorinated dioxins/furans (PCDD/PCDF) in selected environmental samples (soils, sediments, fish, and farm animals) were analyzed from the area of Phong My commune (Thua Thien-Hue province, Vietnam). This area was affected by Agent Orange spraying during the Vietnam war (1968-1971). Whereas PCDD/PCDF content in soil and sediment samples is relatively low and ranges between 0.05 and 5.1 pg WHO-TEQ/g for soils and between 0.7 and 6.4 pg WHO-TEQ/g for sediments, the PCDD/PCDF content in poultry muscle and liver in most cases exceeded the maximum permissible limit of dioxin content per unit fat mass. In some cases of soil and sediments samples, 2,3,7,8-TCDD represented more than 90% of the total PCDD/PCDF, which indicates Agent Orange as the main source.

• MeSH
• Agent Orange MeSH
• chemické defolianty analýza   metabolismus   MeSH
• dioxiny analýza   metabolismus   MeSH
• dobytek metabolismus   MeSH
• furany analýza   metabolismus   MeSH
• kyselina 2,4-dichlorfenoxyoctová analýza   metabolismus   MeSH
• kyselina trichlorfenoxyoctová analýza   metabolismus   MeSH
• látky znečišťující životní prostředí analýza   metabolismus   MeSH
• lidé MeSH
• monitorování životního prostředí * MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• polychlorované dibenzodioxiny analýza   metabolismus   MeSH
• ryby metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Vietnam MeSH
• Názvy látek
• Agent Orange MeSH
• chemické defolianty MeSH
• dioxiny MeSH
• furany MeSH
• kyselina 2,4-dichlorfenoxyoctová MeSH
• kyselina trichlorfenoxyoctová MeSH
• látky znečišťující životní prostředí MeSH
• polychlorované dibenzodioxiny MeSH

Dissolved organic matter (DOM) in freshwaters is present at concentrations ranging from 0.5 to 50 mg L⁻¹, and consists of various organic compounds, including humic substances (HS). HS exert a variety of direct and indirect biological effects, including interaction with the aryl hydrocarbon receptor (AhR). AhR is a cytosolic receptor that binds various hydrophobic organic compounds (HOCs) and mediates some of their toxic effects. In vitro effects of binary mixtures of various DOM (mainly HS) with various HOCs on AhR-mediated responses were studied by use of H4IIE-luc cells. Six out of 12 DOM activated the AhR even at environmentally relevant concentrations (17 mg L⁻¹). In simultaneous exposures of H4IIE-luc cells to DOM (17 mg L⁻¹) and each of the model compounds, 2,3,7,8-TCDD, PCB126, PCB169, benzo[a]pyrene, benzo[a]anthracene, dibenz[a,h]anthracene, fluoranthene, a mixture of persistent organic pollutants (POPs), a mixture of polycyclic aromatic hydrocarbons (PAHs), and a mixture of all HOCs, either significant additive or facilitative effects were observed when compared to activities of single HOCs. No significant decrease of effects due to possible sorption of HOCs to DOM was observed, even in subsequent experiments when HOCs+DOM mixtures were preincubated for six days before exposure to H4IIE-luc. Thus, DOM does not seem to protect organisms against AhR-mediated toxic effects of HOCs (as usually predicted due to sorption of HOCs on DOM), but it can actually enhance their potency for AhR-mediated effects in some situations.

• MeSH
• anthraceny chemie   metabolismus   toxicita   MeSH
• benzopyren chemie   metabolismus   toxicita   MeSH
• fluoreny chemie   metabolismus   toxicita   MeSH
• huminové látky analýza   MeSH
• hydrofobní a hydrofilní interakce MeSH
• krysa rodu Rattus MeSH
• látky znečišťující životní prostředí chemie   metabolismus   toxicita   MeSH
• nádorové buněčné linie MeSH
• organické látky chemie   metabolismus   toxicita   MeSH
• polychlorované dibenzodioxiny chemie   metabolismus   toxicita   MeSH
• polycyklické aromatické uhlovodíky chemie   metabolismus   toxicita   MeSH
• receptory aromatických uhlovodíků metabolismus   MeSH
• sladká voda chemie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• anthracene MeSH Prohlížeč
• anthraceny MeSH
• benzopyren MeSH
• fluoranthene MeSH Prohlížeč
• fluoreny MeSH
• huminové látky MeSH
• látky znečišťující životní prostředí MeSH
• organické látky MeSH
• polychlorované dibenzodioxiny MeSH
• polycyklické aromatické uhlovodíky MeSH
• receptory aromatických uhlovodíků MeSH

Various liver diseases lead to an extensive inflammatory response and release of a number of proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha). This cytokine is known to play a major role in liver regeneration as well as in carcinogenesis. We investigated possible interactions of TNF-alpha with ligands of the aryl hydrocarbon receptor (AhR) and known liver carcinogens, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and coplanar 3,3',4,4',5-pentachlorobiphenyl (PCB 126). These compounds have been previously found to disrupt cell cycle control in contact-inhibited rat liver WB-F344 cells, an in vitro model of adult liver progenitor cells. TNF-alpha itself had no significant effect on the proliferation/apoptosis ratio in the WB-F344 cell line. However, it significantly potentiated proliferative effects of low picomolar range doses of both TCDD and PCB 126, leading to an increase in cell numbers, as well as an increased percentage of cells entering the S-phase of the cell cycle. The combination of TNF-alpha with low concentrations of AhR ligands increased both messenger RNA (mRNA) and protein levels of cyclin A, a principle cyclin involved in disruption of contact inhibition. TNF-alpha temporarily inhibited AhR-dependent induction of cytochrome P450 1A1 (CYP1A1). In contrast, TNF-alpha significantly enhanced induction of CYP1B1 at both mRNA and protein levels, by a mechanism, which was independent of nuclear factor-kappaB activation. These results suggest that TNF-alpha can significantly amplify effects of AhR ligands on deregulation of cell proliferation control, as well as on expression of CYP1B1, which is involved in metabolic activation of a number of mutagenic compounds.

• MeSH
• aromatické hydroxylasy genetika   metabolismus   MeSH
• cytochrom P-450 CYP1A1 genetika   metabolismus   MeSH
• cytochrom P450 CYP1B1 MeSH
• epitelové buňky účinky léků   enzymologie   MeSH
• fixní kombinace léků MeSH
• játra cytologie   MeSH
• karcinogeny metabolismus   toxicita   MeSH
• kmenové buňky účinky léků   enzymologie   MeSH
• krysa rodu Rattus MeSH
• kultivované buňky MeSH
• lékové interakce MeSH
• ligandy MeSH
• polychlorované bifenyly metabolismus   toxicita   MeSH
• polychlorované dibenzodioxiny metabolismus   toxicita   MeSH
• potkani inbrední F344 MeSH
• proliferace buněk účinky léků   MeSH
• receptory aromatických uhlovodíků účinky léků   metabolismus   MeSH
• regulace genové exprese enzymů účinky léků   MeSH
• TNF-alfa farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• 3,4,5,3',4'-pentachlorobiphenyl MeSH Prohlížeč
• aromatické hydroxylasy MeSH
• Cyp1b1 protein, rat MeSH Prohlížeč
• cytochrom P-450 CYP1A1 MeSH
• cytochrom P450 CYP1B1 MeSH
• fixní kombinace léků MeSH
• karcinogeny MeSH
• ligandy MeSH
• polychlorované bifenyly MeSH
• polychlorované dibenzodioxiny MeSH
• receptory aromatických uhlovodíků MeSH
• TNF-alfa MeSH

Cytochrome P450-dependent 7-ethoxyresorufin O-deethylase (EROD), 7-pentoxyresorufin O-dealkylase (PROD) and 7-ethoxycoumarin O-deethylase (ECOD) activities in 14-day-old chick embryo livers were determined 24 h after pretreatment with selected widespread aromatic environmental contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), hexachlorobenzene, and dialkylesters of phthalic acid, and compared with the inducing potencies of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the coplanar and mono-o-chlorinated PCBs. The effects of other model inducers, i.e. phenobarbital and pyrazole, were also examined. Specificity of EROD induction was estimated with regard to contaminants frequently present in environmental samples and dose-response curves for EROD induction were determined. A strong induction (comparable with that by mono-o-chlorinated biphenyl treatment) by dibenzo[a,h]anthracene, benzo[k]fluoranthene or benzo[b]fluoranthene was found, but the maximal level of EROD activity inducible by TCDD was not achieved, partly due to the high toxicity of the tested PAHs. 3-Methylcholanthrene showed moderate inducing potencies; benz[a]anthracene, benzo[a]pyrene, chrysene and 2,2',3,4,4',5'-hexachlorobiphenyl appeared to be weak inducers. Other PAHs and PCBs tested, as well as hexachlorobenzene, dialkyl phthalates, phenobarbital and pyrazole had no marked effects on the EROD level. ECOD activities were increased non-specifically by TCDD, 3-methylcholanthrene, hexachlorobenzene and phenobarbital. A significant enhancement of PROD activity by TCDD and related inducers was observed, while phenobarbital induced the PROD activity only weakly; SDS-PAGE analysis showed that the chicken phenobarbital-inducible cytochromes P4502H with apparent molecular weights 50 kDa were not markedly induced by the TCDD- or 3-methylcholanthrene treatments. Inhibition of EROD and PROD by 9-hydroxyellipticine, a specific inhibitor of rat hepatic cytochrome P4501A1, revealed that PROD induction by TCDD and other P4501A-inducers was probably a result of a broader substrate specificity of chick embryo P4501A. Measurement of EROD activities in chick embryo liver is highly sensitive, specific and suitable for the determination of TCDD-type toxicity of new drugs, agrochemicals, and industrial pollutants.

• MeSH
• 7-alkoxykumarin-O-dealkylasa biosyntéza   MeSH
• cytochrom P-450 CYP1A1 biosyntéza   MeSH
• cytochrom P-450 CYP2B1 biosyntéza   MeSH
• enzymová indukce účinky léků   MeSH
• jaterní mikrozomy účinky léků   enzymologie   MeSH
• kuřecí embryo MeSH
• látky znečišťující životní prostředí metabolismus   toxicita   MeSH
• oxidoreduktasy biosyntéza   MeSH
• polychlorované bifenyly metabolismus   toxicita   MeSH
• polychlorované dibenzodioxiny metabolismus   toxicita   MeSH
• polycyklické aromatické uhlovodíky metabolismus   toxicita   MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 7-alkoxykumarin-O-dealkylasa MeSH
• cytochrom P-450 CYP1A1 MeSH
• cytochrom P-450 CYP2B1 MeSH
• látky znečišťující životní prostředí MeSH
• oxidoreduktasy MeSH
• polychlorované bifenyly MeSH
• polychlorované dibenzodioxiny MeSH
• polycyklické aromatické uhlovodíky MeSH