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Roel P F Schins - One of the best experts on this subject based on the ideXlab platform.
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Genotoxicity of poorly soluble particles.
Inhalation toxicology, 2007Co-Authors: Roel P F Schins, Ad M KnaapenAbstract:Poorly soluble particles such as TiO2, carbon black, and diesel exhaust particles have been evaluated for their Genotoxicity using both in vitro and in vivo assays, since inhalation of these compounds by rats at high concentrations has been found to lead to tumor formation. Two principle modes of genotoxic action can be considered for particles, referred to as primary and secondary Genotoxicity. Primary Genotoxicity is defined as genetic damage elicited by particles in the absence of pulmonary inflammation, whereas secondary Genotoxicity implies a pathway of genetic damage resulting from the oxidative DNA attack by reactive oxygen/nitrogen species (ROS/RNS), generated during particle-elicited inflammation. Conceptually, primary Genotoxicity might operate via various mechanisms, such as the actions of ROS (e.g., as generated from reactive particle surfaces), or DNA-adduct formation by reactive metabolites of particle-associated organic compounds (e.g., polycyclic aromatic hydrocarbons). Currently available literature data, however, merely indicate that the tumorigenesis of poorly soluble particles involves a mechanism of secondary Genotoxicity. However, further research is urgently required, since (1) causality between pulmonary inflammation and Genotoxicity has not yet been established, and (2) effects of inflammation on fundamental DNA damage responses that orchestrate mutagenesis and carcinogenic outcome,that is, cell cycle arrest, DNA repair, proliferation, and apoptosis, are currently poorly understood.
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Genotoxicity of Poorly Soluble Particles
Inhalation Toxicology, 2007Co-Authors: Roel P F Schins, Ad M KnaapenAbstract:Poorly soluble particles such as TiO2, carbon black, and diesel exhaust particles have been evaluated for their genotoxity using both in vitro and in vivo assays, since inhalation of these compounds by rats at high concentrations has been found to lead to tumor formation. Two principle modes of genotoxic action can be considered for particles, referred to as primary and secondary Genotoxicity. Primary Genotoxicity is defined as genetic damage elicited by particles in the absence of pulmonary inflammation, whereas secondary Genotoxicity implies a pathway of genetic damage resulting from the oxidative DNA attack by reactive oxygen/nitrogen species (ROS/RNS), generated during particle-elicited inflammation. Conceptually, primary Genotoxicity might operate via various mechanisms, such as the actions of ROS (e.g., as generated from reactive particle surfaces), or DNA–adduct formation by reactive metabolites of particle-associated organic compounds (e.g., polycyclic aromatic hydrocarbons). Currently available l...
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Mechanisms of Genotoxicity of particles and fibers.
Inhalation toxicology, 2002Co-Authors: Roel P F SchinsAbstract:With regard to Genotoxicity testing and cancer risk assessment, particles and fibers form a rather specific group among all toxicants. First, the physicochemical behavior of fibrous and nonfibrous particles is usually very different from that of nonparticulate, chemical carcinogens. Reactive oxygen species (ROS) are believed to play a major role in primary Genotoxicity of particles, which may derive from their surface properties, the presence of transition metals, intracellular iron mobilization, and lipid peroxidation. Other aspects relevant to primary Genotoxicity are particle size, shape, crystallinity (e.g., silica), and solubility, and may also include particle uptake, interaction with cell division machinery (e.g., asbestos), and the presence of mutagens carried with the particle (e.g., diesel exhaust particles, DEP). Excessive and persistent formation of ROS from inflammatory cells is considered as the hallmark of the secondary Genotoxicity of nonfibrous and fibrous particles. Since lung inflammati...
Ad M Knaapen - One of the best experts on this subject based on the ideXlab platform.
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Genotoxicity of poorly soluble particles.
Inhalation toxicology, 2007Co-Authors: Roel P F Schins, Ad M KnaapenAbstract:Poorly soluble particles such as TiO2, carbon black, and diesel exhaust particles have been evaluated for their Genotoxicity using both in vitro and in vivo assays, since inhalation of these compounds by rats at high concentrations has been found to lead to tumor formation. Two principle modes of genotoxic action can be considered for particles, referred to as primary and secondary Genotoxicity. Primary Genotoxicity is defined as genetic damage elicited by particles in the absence of pulmonary inflammation, whereas secondary Genotoxicity implies a pathway of genetic damage resulting from the oxidative DNA attack by reactive oxygen/nitrogen species (ROS/RNS), generated during particle-elicited inflammation. Conceptually, primary Genotoxicity might operate via various mechanisms, such as the actions of ROS (e.g., as generated from reactive particle surfaces), or DNA-adduct formation by reactive metabolites of particle-associated organic compounds (e.g., polycyclic aromatic hydrocarbons). Currently available literature data, however, merely indicate that the tumorigenesis of poorly soluble particles involves a mechanism of secondary Genotoxicity. However, further research is urgently required, since (1) causality between pulmonary inflammation and Genotoxicity has not yet been established, and (2) effects of inflammation on fundamental DNA damage responses that orchestrate mutagenesis and carcinogenic outcome,that is, cell cycle arrest, DNA repair, proliferation, and apoptosis, are currently poorly understood.
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Genotoxicity of Poorly Soluble Particles
Inhalation Toxicology, 2007Co-Authors: Roel P F Schins, Ad M KnaapenAbstract:Poorly soluble particles such as TiO2, carbon black, and diesel exhaust particles have been evaluated for their genotoxity using both in vitro and in vivo assays, since inhalation of these compounds by rats at high concentrations has been found to lead to tumor formation. Two principle modes of genotoxic action can be considered for particles, referred to as primary and secondary Genotoxicity. Primary Genotoxicity is defined as genetic damage elicited by particles in the absence of pulmonary inflammation, whereas secondary Genotoxicity implies a pathway of genetic damage resulting from the oxidative DNA attack by reactive oxygen/nitrogen species (ROS/RNS), generated during particle-elicited inflammation. Conceptually, primary Genotoxicity might operate via various mechanisms, such as the actions of ROS (e.g., as generated from reactive particle surfaces), or DNA–adduct formation by reactive metabolites of particle-associated organic compounds (e.g., polycyclic aromatic hydrocarbons). Currently available l...
M Bueno - One of the best experts on this subject based on the ideXlab platform.
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cytotoxicity and Genotoxicity of sodium percarbonate a comparison with bleaching agents commonly used in discoloured pulpless teeth
International Endodontic Journal, 2010Co-Authors: Maria Raquel Fernandez, Rodrigo Varella De Carvalho, Fabricio Aulo Ogliari, F A Beira, Adriana Etges, M BuenoAbstract:Fernandez MR, Carvalho RV, Ogliari FA, Beira FA, Etges A, Bueno M. Cytotoxicity and Genotoxicity of sodium percarbonate: a comparison with bleaching agents commonly used in discoloured pulpless teeth. International Endodontic Journal, 43, 102–108, 2010. Abstract Aim To evaluate the cytotoxicity and Genotoxicity of sodium percarbonate (SPC) in comparison with bleaching agents used on discoloured pulpless teeth. Methodology The cytotoxicity and Genotoxicity of bleaching agents were evaluated both in their pure form as well as at concentrations commonly used in clinical practice. Hydrogen peroxide (HP), carbamide peroxide (CP), sodium perborate (SP) and SPC were diluted in Dulbecco’s modified Eagle’s medium (DMEM) in series. To evaluate the cytotoxicity, the survival of 3T3/NIH mouse fibroblasts was measured photometrically using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay after a 24 h-exposure period. Genotoxicity was indicated by micronuclei (MN) formation, and modification of the normal cell was analysed by light microscopy (400×). Statistical analysis was performed by one-way anova, followed by a multiple-comparison Tukey post hoc test (P < 0.05). Results All groups exhibited a dose-dependent cytotoxicity. However, CP showed a similar cytotoxic effect when compared with DMEM-untreated control (UC) group. HP and SPC were significantly more cytotoxic than SP. The Genotoxicity test showed that SPC and SP had an intermediate rate of MN frequency when compared with the UC group. The mean rate of MN frequency for HP was higher and statistically more significant than for the other groups tested. No difference was observed when CP and UC groups were compared. Conclusions Sodium percarbonate showed cytotoxicity and Genotoxicity similar to those of the other products tested. However, before SPC is used clinically, studies should be conducted to confirm its safety in vivo.
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Cytotoxicity and Genotoxicity of sodium percarbonate: a comparison with bleaching agents commonly used in discoloured pulpless teeth
International endodontic journal, 2010Co-Authors: Maria Raquel Fernandez, Rodrigo Varella De Carvalho, Fabricio Aulo Ogliari, F A Beira, Adriana Etges, M BuenoAbstract:Fernandez MR, Carvalho RV, Ogliari FA, Beira FA, Etges A, Bueno M. Cytotoxicity and Genotoxicity of sodium percarbonate: a comparison with bleaching agents commonly used in discoloured pulpless teeth. International Endodontic Journal, 43, 102–108, 2010. Abstract Aim To evaluate the cytotoxicity and Genotoxicity of sodium percarbonate (SPC) in comparison with bleaching agents used on discoloured pulpless teeth. Methodology The cytotoxicity and Genotoxicity of bleaching agents were evaluated both in their pure form as well as at concentrations commonly used in clinical practice. Hydrogen peroxide (HP), carbamide peroxide (CP), sodium perborate (SP) and SPC were diluted in Dulbecco’s modified Eagle’s medium (DMEM) in series. To evaluate the cytotoxicity, the survival of 3T3/NIH mouse fibroblasts was measured photometrically using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay after a 24 h-exposure period. Genotoxicity was indicated by micronuclei (MN) formation, and modification of the normal cell was analysed by light microscopy (400×). Statistical analysis was performed by one-way anova, followed by a multiple-comparison Tukey post hoc test (P
Metka Filipic - One of the best experts on this subject based on the ideXlab platform.
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combination of in vitro bioassays for the determination of cytotoxic and genotoxic potential of wastewater surface water and drinking water samples
Chemosphere, 2009Co-Authors: Bojana žegura, Ester Heath, Andrej Cernosa, Metka FilipicAbstract:In this study we evaluated Genotoxicity and cytotoxicity of native samples of wastewaters (15 samples), surface waters (28 samples) and potable waters (8 samples) with the SOS/umuC assay with Salmonella typhimurium TA1535/pSK1002 and MTT assay with human hepatoma HepG2 cells. The Genotoxicity of selected samples was confirmed with the comet assay with HepG2 cells. In the SOS/umuC assay 13 out of the 51 samples were genotoxic: two effluent samples from chemical industry; one sample of wastewater treatment plant effluent; two hospital wastewater samples; three river water samples and four lake water samples. Six samples were cytotoxic for HepG2 cells: both effluent samples of chemical industry, two wastewater treatment plant effluent samples, and two river water samples, however, only the chemical industry effluent samples were genotoxic and cytotoxic, indicating that different contaminants are responsible for genotoxic and toxic effects. Comparing Genotoxicity of river and lake water samples with the chemical analytical data of the presence of the residues of pharmaceutical and personal care products (non-steroidal anti-inflammatory drugs, UV filters and disinfectants) in these samples, indicated that the presence of UV filters might be linked to the Genotoxicity of these samples. The results showed that the application of the bacterial SOS/umuC assay and mammalian cell assays (MTT and comet assay) with HepG2 cells was suitably sensitive combination of assays to monitor Genotoxicity and cytotoxicity of native samples of wastewaters and surface waters. With this study we also confirmed that the toxicity/Genotoxicity bioassays should be an integral tool in the evaluation of toxicity of complex wastewaters before the release into environment, as well as for the monitoring of surface water quality, providing data useful in risk assessment.
Maria Raquel Fernandez - One of the best experts on this subject based on the ideXlab platform.
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cytotoxicity and Genotoxicity of sodium percarbonate a comparison with bleaching agents commonly used in discoloured pulpless teeth
International Endodontic Journal, 2010Co-Authors: Maria Raquel Fernandez, Rodrigo Varella De Carvalho, Fabricio Aulo Ogliari, F A Beira, Adriana Etges, M BuenoAbstract:Fernandez MR, Carvalho RV, Ogliari FA, Beira FA, Etges A, Bueno M. Cytotoxicity and Genotoxicity of sodium percarbonate: a comparison with bleaching agents commonly used in discoloured pulpless teeth. International Endodontic Journal, 43, 102–108, 2010. Abstract Aim To evaluate the cytotoxicity and Genotoxicity of sodium percarbonate (SPC) in comparison with bleaching agents used on discoloured pulpless teeth. Methodology The cytotoxicity and Genotoxicity of bleaching agents were evaluated both in their pure form as well as at concentrations commonly used in clinical practice. Hydrogen peroxide (HP), carbamide peroxide (CP), sodium perborate (SP) and SPC were diluted in Dulbecco’s modified Eagle’s medium (DMEM) in series. To evaluate the cytotoxicity, the survival of 3T3/NIH mouse fibroblasts was measured photometrically using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay after a 24 h-exposure period. Genotoxicity was indicated by micronuclei (MN) formation, and modification of the normal cell was analysed by light microscopy (400×). Statistical analysis was performed by one-way anova, followed by a multiple-comparison Tukey post hoc test (P < 0.05). Results All groups exhibited a dose-dependent cytotoxicity. However, CP showed a similar cytotoxic effect when compared with DMEM-untreated control (UC) group. HP and SPC were significantly more cytotoxic than SP. The Genotoxicity test showed that SPC and SP had an intermediate rate of MN frequency when compared with the UC group. The mean rate of MN frequency for HP was higher and statistically more significant than for the other groups tested. No difference was observed when CP and UC groups were compared. Conclusions Sodium percarbonate showed cytotoxicity and Genotoxicity similar to those of the other products tested. However, before SPC is used clinically, studies should be conducted to confirm its safety in vivo.
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Cytotoxicity and Genotoxicity of sodium percarbonate: a comparison with bleaching agents commonly used in discoloured pulpless teeth
International endodontic journal, 2010Co-Authors: Maria Raquel Fernandez, Rodrigo Varella De Carvalho, Fabricio Aulo Ogliari, F A Beira, Adriana Etges, M BuenoAbstract:Fernandez MR, Carvalho RV, Ogliari FA, Beira FA, Etges A, Bueno M. Cytotoxicity and Genotoxicity of sodium percarbonate: a comparison with bleaching agents commonly used in discoloured pulpless teeth. International Endodontic Journal, 43, 102–108, 2010. Abstract Aim To evaluate the cytotoxicity and Genotoxicity of sodium percarbonate (SPC) in comparison with bleaching agents used on discoloured pulpless teeth. Methodology The cytotoxicity and Genotoxicity of bleaching agents were evaluated both in their pure form as well as at concentrations commonly used in clinical practice. Hydrogen peroxide (HP), carbamide peroxide (CP), sodium perborate (SP) and SPC were diluted in Dulbecco’s modified Eagle’s medium (DMEM) in series. To evaluate the cytotoxicity, the survival of 3T3/NIH mouse fibroblasts was measured photometrically using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay after a 24 h-exposure period. Genotoxicity was indicated by micronuclei (MN) formation, and modification of the normal cell was analysed by light microscopy (400×). Statistical analysis was performed by one-way anova, followed by a multiple-comparison Tukey post hoc test (P