Search results for "Micronucleus test"
showing 10 items of 40 documents
Photocatalytic Degradation of Paraquat and Genotoxicity of its Intermediate Products
2007
Abstract The photocatalytic degradation of paraquat (1,1-dimethyl-4,4′-bipyridylium dichloride) aqueous solutions in the presence of polycrystalline TiO2 Degussa P25 irradiated by near-UV light was investigated. The substrate and total organic carbon concentrations were monitored by UV spectroscopy and TOC measurements, respectively: the complete photocatalytic mineralization of paraquat (20 ppm) was achieved after ca. 3 h of irradiation by using 0.4 g l−1 of catalyst amount at natural pH (ca 5.8). On the contrary no significant photodegradation of paraquat was observed in the absence of TiO2 under similar experimental conditions. To evaluate the genotoxicity of paraquat and its intermediat…
Induction of micronuclei in V79 Chinese hamster cells by tetrachlorohydroquinone, a metabolite of pentachlorophenol
1992
Tetrachlorohydroquinone, a metabolite of the fungicide pentachlorophenol, induced significant dose-related increases in micronuclei in V79 Chinese hamster cells without exogenous metabolic activation. The lowest observed effective dose was 10 microM, where the relative survival was about 62%. At the highest dose tested, 20 microM, the relative survival was about 8% and the frequency of cells with micronuclei was about 6 times the solvent control frequency. The induction of micronuclei by tetrachlorohydroquinone was significantly inhibited by the hydroxyl radical scavenger dimethyl sulfoxide at 5% (v/v).
Toxicity of a dental adhesive compared with ionizing radiation and zoledronic acid
2015
Background: To determine the toxicity of aqueous dilutions of a universal self-priming dental adhesive (DA) and comparing these with those elicited by exposure to ionizing radiation (IR), Zoledronic acid (Z) treatment and the synergic effects of the combined treatment with IR+Z. Material and Methods: The genotoxic effect of DA was determined by the increase in the frequency of micronuclei in cytokinesis-blocked in cultured human lymphocytes before and after exposure to 2Gy of X-rays. The cytotoxic effect was studied by using the MTT cell viability test in normal prostate cell lines (PNT2) after exposure to different X-ray doses (0Gy-20Gy). The cell lines divided into different groups and tr…
The influence of automobile exhausts on mutagenicity of soils: contamination with, fractionation, separation, and preliminary identification of mutag…
2000
To test the assumption that automobile exhausts contribute to soil mutagenicity, two soils with low levels of mutagenic activities were exposed to traffic exhausts at a heavily charged junction of German motorways (Autobahnen) for 3, 7, 10, 13, 17, 21, and 26 weeks. Indeed, in the presence of a metabolic activation system from rat liver (S9), an average increase of 8 and 9 (4 and 12) revertants per gram per week was found in Salmonella typhimurium TA 98 (TA 100). In the absence of S9, meaningful measurements were impossible on account of a concurrent dose dependent increase of toxicity. No correlation between the increase of mutagenicity and the contents of polycyclic aromatic hydrocarbons …
Squaraine Dyes for Photodynamic Therapy: Study of Their Cytotoxicity and Genotoxicity in Bacteria and Mammalian Cells¶‡
2007
Halogenated squaraine dyes are characterized by long wavelength absorption (>600 nm) and high triplet yields and therefore represent new types of photosensitizers that could be useful for photodynamic therapy. We have analyzed the cytotoxicity and genotoxicity of the bromo derivative 1, the iodo derivative 2 and the corresponding nonhalogenated dye 3 in the absence and presence of visible light. At concentrations of 1-2 microM, 1 and 2 reduced the cloning efficiency of AS52 Chinese hamster ovary cells to less than 1% under conditions that were well tolerated in the dark. Similarly, the proliferation of L5178Y mouse lymphoma cells was inhibited by photoexcited 1 and 2 with high selectivity. …
Evaluation of the genotoxic and cytochrome P450 monooxygenase‐inhibitory potential of dicuran on procaryotic and eucaryotic test systems
2000
The effect of the herbicide Dicuran 500 FL (formulated product) on the phenotypical and genotypical changes in procaryotic and eucaryotic organisms was investigated using short-term tests for detecting genotoxins. Since pesticides discharged in the water environment can modulate the mixed-function monooxygenases (MFO) detoxification system of water organisms, the in vivo and in vitro effects of Dicuran on hepatic cytochrome P450 (cyt P450) monooxygenase activities were also examined in juvenile carp (Cyprinus carpio L.). By measuring the activities of MFO in experimental carp exposed to Dicuran an attempt was made to establish whether Dicuran could be bioactivated by MFO into ultimate mutag…
Genotoxic and endocrine activities of bis(hydroxyphenyl)methane (bisphenol F) and its derivatives in the HepG2 cell line
2008
International audience; Human can be exposed to bis(hydroxyphenyl)methane (bisphenol F or BPF) and its derivatives as environment and food's contaminants. This study was investigated to identify and to compare toxic potency of BPF, BFDGE, and two of BPF metabolites using in vitro methods. BPF did not induce any genic mutation in bacteria when the Ames test was performed according to the OECD guideline. In contrast, using Human cell lines and Comet assay, we demonstrated that BPF and Bisphenol F Diglycidyl Ether (BFDGE) were effective on HepG2 cell DNA fragmentation at non-cytotoxic concentrations. DHB was also positive but at higher concentrations, near its limit of solubility. Neither BPF,…
Importance of the toxicological tests in the application and safety of ozone therapy
2018
Until today, there is not any official registry of the different routes of systemic ozone therapy. With the aim to prove the safety of this therapy, several ways of ozone (O3) applications were evaluated, such as rectal insufflation (RI), major autohemotherapy (M-AHT) and intraperitoneal application (IP). For RI, some toxicological tests were performed such as: acute, sub-chronic, mutagenic (bone marrow chromosomic aberrations and micronucleus), teratogenic and irritation studies (at 40 mg/L and 10 mL during 15 days). For M-AHT, acute toxicological (in rats with 21, 47 and 64 mg/L and a volume of 2 mL with daily evaluation up to 15 days) and mutagenic (chromosomal aberration analysis, micr…
Usefulness of biomarkers as intermediate endpoints in health risks posed by occupational lead exposure
2015
The article concerns potential harmful effects of exposure to lead. Although the occurrence of severe lead poisoning has receded in several countries, occupational exposure resulting in moderate and clinically symptomatic toxicity is still common. An earlier and precise characterization of an individual response is obligatory in order to assess the possible risks for human health. Biomarkers may fill important gaps in the path from exposure to a disease. Specifically speaking, emerging (DNA double strand breaks and telomeric DNA erosion) and validated (micronuclei induction and chromosomal aberrations) biomarkers of genotoxicity seem to provide evidence for the assessment of molecular and c…
Comparative study of oral micronucleated cell frequency in oral submucous fibrosis patients and healthy individuals
2011
Objectives: To determine the frequency of micronucleated cells and micronuclei in oral submucous fibrosis patients and to compare with healthy individuals. Study design: Twenty patients with oral submucous fibrosis and twenty age-sex-matched healthy individuals as control group participated in this study. Exfoliated cells were obtained by scraping from right and left buccal mucosa and were screened for micronucleated cells and micronuclei. Frequencies were compared between oral submucous fibrosis and control group. Also comparison was made between chewing site and non-chewing site of buccal mucosa. Results: Frequency of micronucleated cells and micronuclei in oral submucous fibrosis patient…