• MeSH
• COVID-19 * imunologie   MeSH
• lidé MeSH
• metaanalýza jako téma MeSH
• protilátky virové * krev   MeSH
• Check Tag
• lidé MeSH

Pollution of surface soils by traffic, especially along major highways, can be a significant issue. Numerous studies have demonstrated traffic to be an important source of particulate matter and gas-phase organic air pollutants that produce many types of deleterious effects. This article brings original information about the presence of contaminants with specific mechanisms of action in traffic-influenced soils as determined by bioanalytical approaches and instrumental analyses. The initial phase of the study aimed to compare contamination of soils near highways with those from reference localities, whereas the second phase of the study investigated the influence of traffic pollution in soils at various distances from highways. For the reference areas, forest soils contained greater concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQs; 483 to 2094 pg/g) than did arable soils (96 to 478 pg/g), which represent the relevant reference for the studied soils along highways. The total concentration of TCDD-EQs determined in the in vitro transactivation assay ranged from 225 to 27,700 pg/g in traffic-affected soils. The greatest concentration of TCDD-EQs among the studied sites was observed in soils collected near highway D1, which is the primary thoroughfare in the Czech Republic. The concentrations of TCDD-EQs in roadside soils were the greatest and decreased with increased distance from highways, and this spatial distribution corresponded with the levels of polycyclic aromatic hydrocarbons (PAHs). Soils collected 100 m away from highways in most cases contained concentrations of TCDD-EQs similar to background values. Most TCDD-EQ presence was caused by nonpersistent compounds in soils, with a significant contribution from PAHs as well as other unknown nonpersistent chemicals. Extracts from most soils collected near highways exhibited antiestrogenic and in some cases antiandrogenic activities; for several sites the activity was also detected in soils farther from highways. The presence of TCDD-EQs and antihormonal activity in highway-affected soils points to traffic as a source of polluting compounds having specific effects.

• MeSH
• dioxiny analýza   MeSH
• endokrinní disruptory analýza   MeSH
• látky znečišťující půdu analýza   MeSH
• monitorování životního prostředí MeSH
• motorová vozidla MeSH
• půda analýza   normy   MeSH
• Publikační typ
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

Humic substances (HS) were for decades regarded as inert in the ecosystems with respect to their possible toxicity. However, HS have been recently shown to elicit various adverse effects generally attributed to xenobiotics. In our study, we used MVLN and H4IIE-luc cell lines stably transfected with luciferase gene under control of estrogen receptor (ER) and Ah receptor (AhR; receptor connected with so-called dioxin-like toxicity) for assessment of anti/estrogenic and AhR-mediated effects of 12 commercially available humic substances. Out of those, five humic acids were shown to induce AhR-mediated activity with relative potencies related to TCDD 2.6 x 10(-8)-7.4 x 10(-8). Organic extracts of HS solutions also elicited high activities what means that lipophilic molecules are responsible for a great part of effect. However, relatively high activity remaining in extracted solution suggests also presence of polar AhR-agonists. Contribution of persistent organic compounds to the observed effects was ruled out by H(2)SO(4) treatment. Eight out of twelve HS elicited significant antiestrogenic effects with IC(50) ranging from 40 to 164 mg l(-1). The possible explanations of the antiestrogenic effect include sorption of 17-beta-estradiol (E2) on HS, changes in membrane permeability for E2 or another specific mechanism.

• MeSH
• benzopyrany toxicita   MeSH
• financování organizované MeSH
• huminové látky toxicita   MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• modulátory estrogenních receptorů farmakologie   MeSH
• nádorové buněčné linie MeSH
• polychlorované dibenzodioxiny toxicita   MeSH
• receptory aromatických uhlovodíků fyziologie   účinky léků   MeSH
• receptory pro estrogeny účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• zvířata MeSH

Retinoids are known to regulate important processes such as differentiation, development, and embryogenesis. Some effects, such as malformations in frogs or changes in metabolism of birds, could be related to disruption of the retinoid signaling pathway by exposure to organic contaminants. A new reporter gene assay has been established for evaluation of the modulation of retinoid signaling by individual chemicals or environmental samples. The bioassay is based on the pluripotent embryonic carcinoma cell line P19 stably transfected with the firefly luciferase gene under the control of a retinoic acid-responsive element (clone P19/ A15). The cell line was used to characterize the effects of individual chemicals and sediments extracts on retinoid signaling pathways. The extracts of sediments from the River Kymi, Finland, which contained polychlorinated dioxins and furans and polycyclic aromatic hydrocarbons (PAHs), significantly increased the potency of all-trans retinoic acid (ATRA), while no effect was observed with the extract of the sediment from reference locality. Considerable part of the effect was caused by the labile fraction of the sediment extracts. Also, several individual PAHs potentiated the effect of ATRA; on the other hand, 2,3,7,8-tetrachlorodibenzo-p-dioxin and several phthalates showed slightly inhibiting effect. These results suggest that PAHs could be able to modulate the retinoid signaling pathway and that they could be responsible for a part of the proretinoid activity observed in the sediment extracts. However, the effects of PAHs on the retinoic acid signaling pathways do not seem to be mediated directly by crosstalk with aryl hydrocarbon receptor.

• MeSH
• biotest metody   MeSH
• dioxiny analýza   toxicita   MeSH
• embryonální karcinom patologie   MeSH
• financování organizované MeSH
• furany analýza   toxicita   MeSH
• geologické sedimenty chemie   MeSH
• hodnocení rizik MeSH
• kyseliny ftalové analýza   toxicita   MeSH
• látky znečišťující životní prostředí analýza   toxicita   MeSH
• luciferasy světlušek genetika   MeSH
• nádorové buněčné linie MeSH
• polycyklické aromatické uhlovodíky analýza   toxicita   MeSH
• reportérové geny MeSH
• retinoidy genetika   metabolismus   MeSH
• signální transdukce MeSH
• tretinoin analýza   toxicita   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Geografické názvy
• Finsko MeSH

Toxic effects of many persistent organic pollutants (e.g., polychlorinated biphenyls or polychlorinated dibenzo-p-dioxins and furans) are mediated via the aryl hydrocarbon receptor (AhR). Although polycyclic aromatic hydrocarbons (PAHs) and their derivatives also activate AhR, their toxic effects remain to be fully elucidated. In the present study, we used the in vitro H4IIE-luc transactivation cell assay to investigate cytotoxicity and potencies to activate AhR by 29 individual PAHs and their N-heterocyclic derivatives (aza-PAHs). The aza-PAHs were found to be significantly more cytotoxic and more potent inducers of AhR than their unsubstituted analogues. Several aza-PAHs, such as dibenz[a,h]acridine or dibenz[a,i]acridine, activated AhR within picomolar concentrations, comparable to the effects of reference 2,3,7,8-tetrachlorodibenzo-p-dioxin. Ellipsoidal volume, molar refractivity, and molecular size were the most important descriptors derived from the modeling of quantitative structure-activity relationships for potencies to activate AhR. Comparable relative toxic potencies (induction equivalency factors) for individual aza-PAHs are derived, and their use for evaluation of complex contaminated samples is discussed.

• MeSH
• biotest MeSH
• financování organizované MeSH
• heterocyklické sloučeniny chemie   toxicita   MeSH
• hydrofobní a hydrofilní interakce MeSH
• krysa rodu rattus MeSH
• kvantitativní vztahy mezi strukturou a aktivitou MeSH
• molekulární struktura MeSH
• nádorové buněčné linie MeSH
• polycyklické aromatické uhlovodíky chemie   toxicita   MeSH
• receptory aromatických uhlovodíků genetika   metabolismus   MeSH
• regulace genové exprese účinky záření   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH

A group of intracellular nuclear receptors is a protein superfamily including arylhydrocarbon AhR, estrogen ER, androgen AR, thyroid TR and retinoid receptors RAR/RXR as well as molecules with unknown function known as orphan receptors. These proteins play an important role in a wide range of physiological as well as toxicological processes acting as transcription factors (ligand-dependent signalling macromolecules modulating expression of various genes in a positive or negative manner). A large number of environmental pollutants and other xenobiotics negatively affect signaling pathways, in which nuclear receptors are involved, and these modulations were related to important in vivo toxic effects such as immunosuppression, carcinogenesis, reproduction or developmental toxicity, and embryotoxicity. Presented review summarizes current knowledge on major nuclear receptors (AhR, ER, AR, RAR/RXR, TR) and their relationship to known in vivo toxic effects. Special attention is focused on priority organic environmental contaminants and experimental approaches for determination and studies of specific toxicity mechanisms.

• MeSH
• endokrinní disruptory otrava   MeSH
• financování organizované MeSH
• látky znečišťující životní prostředí otrava   MeSH
• lidé MeSH
• receptory cytoplazmatické a nukleární metabolismus   MeSH
• techniky in vitro MeSH
• testy toxicity MeSH
• xenobiotika toxicita   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• přehledy MeSH

• MeSH
• biologické modely MeSH
• bisfenol A-glycidyl methakrylát metabolismus   MeSH
• cytochrom P-450 CYP1A1 antagonisté a inhibitory   MeSH
• estrogeny biosyntéza   MeSH
• nádorové buňky kultivované MeSH
• polychlorované dibenzodioxiny toxicita   MeSH
• techniky in vitro MeSH

• MeSH
• automobily MeSH
• finanční podpora výzkumu jako téma MeSH
• látky znečišťující půdu analýza   MeSH
• polychlorované dibenzodioxiny toxicita   MeSH
• testy toxicity MeSH
• výfukové emise vozidel škodlivé účinky   toxicita   MeSH

• MeSH
• bifenylové sloučeniny chemická syntéza   toxicita   MeSH
• chlorfenoly chemie   toxicita   účinky záření   MeSH
• fenoly toxicita   MeSH
• finanční podpora výzkumu jako téma MeSH
• krysa rodu rattus MeSH
• látky znečišťující životní prostředí toxicita   MeSH
• led MeSH
• molekulární struktura MeSH
• pesticidy chemie   MeSH
• Vibrio účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH

• MeSH
• hnací plyny analýza   MeSH
• látky znečišťující vzduch analýza   MeSH
• polycyklické aromatické uhlovodíky analýza   MeSH
• vysokoúčinná kapalinová chromatografie MeSH