Search results for "Agens"
showing 10 items of 172 documents
Genotoxicity of dental materials.
1996
This study was performed to characterize the (possible) DNA-damaging properties of dental materials and to identify specific compounds that contribute to this genotoxicity. For screening, three tests that assay for different aspects of genotoxicity (i) the bacterial umu-test; (ii) the eucaryotic DNA synthesis inhibition test; and (iii) the in vivo alkaline filter elution technique were chosen. This investigation gives several lines of evidence that most dental materials tested (14 chemical monosubstances present in dental devices and 7 extracts of dental materials) yield 'positive' results in at least one of the genotoxicity tests, however, with effects ranging from 'borderline' to 'strong …
XML document-grammar comparison: related problems and applications
2011
10.2478/s13537-011-0005-1; International audience; XML document comparison is becoming an ever more popular research issue due to the increasingly abundant use of XML. Likewise, a growing interest fosters the development of XML grammar matching and comparison, due to the proliferation of heterogeneous XML data sources, particularly on the Web. Nonetheless, the process of comparing XML documents with XML grammars, i.e., XML document and grammar similarity evaluation, has not yet received the attention it deserves. In this paper, we provide an overview on existing research related to XML document/grammar comparison, presenting the background and discussing the various techniques related to th…
A comparative investigation of DNA adducts, DNA strand breaks and gene mutations induced by benzo[a]pyrene and (+/-)-anti-benzo[a]pyrene-7,8-diol 9,1…
1997
Abstract Genotoxic effects of benzo[ a ]pyrene (BP) and its reactive metabolites (±)- anti -benzo[ a ]pyrene-7,8-diol 9,10-oxide ((±)- anti -BPDE) were comparatively investigated in vitro with the permanent human fibroblast cell line MRC5CV1. Induced DNA adducts were measured by 32 P-postlabeling, DNA strand breakage was determined by the comet assay and the HPRT gene mutation test was used to detect cytotoxicity and mutagenicity. Treatment of MRC5CV1 cells with S9 mix-activated BP or with (±)- anti -BPDE resulted in a concentration-dependent increase in DNA adducts and strand breaks. Genotoxic effects of BP and (±)- anti- BPDE were detected by 32 P-postlabeling and the comet assay with sim…
Swimming pool water--fractionation and genotoxicological characterization of organic constituents.
2005
Swimming pool water treatment in general includes flocculation, sand filtration, and subsequent disinfection with chlorine. The continuous chlorination and input of organic material by bathers in combination with recirculation of the pool water leads to an accumulation of disinfection by-products (DBPs) in the water. Several DBPs have been identified as human carcinogens and are thought to cause allergic asthma. Therefore, the elimination of DBPs is one major aim of pool water treatment. Using membrane filtration as an alternative treatment technology, DBPs can be removed more efficiently than with conventional treatment. In this study membrane filtration and genotoxicity testing were appli…
Isolation and Characterization of Structurally Novel Antimutagenic Flavonoids from Spinach (Spinacia oleracea)
2001
Thirteen compounds, isolated from spinach (Spinacia oleracea), acted as antimutagens against the dietary carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline in Salmonella typhimurium TA 98. The antimutagens were purified by preparative and micropreparative HPLC from a methanol/water (70:30, v/v) extract of dry spinach (commercial product) after removal of lipophilic compounds such as chlorophylls and carotenoids by solid-phase extraction (SPE). Pure active compounds were identified by instrumental analysis including FT-IR, (1)H and (13)C NMR, UV-vis spectroscopy, and mass spectrometry. All of these compounds were flavonoids and related compounds that could be attributed to five groups: (A, m…
Occurrence, mitigation and in vitro cytotoxicity of nivalenol, a type B trichothecene mycotoxin - Updates from the last decade (2010-2020).
2021
Abstract The present review aims to give an overview of the literature of the last decade (2010–2020) concerning the occurrence of the type B trichothecene mycotoxin nivalenol (NIV) and its in vitro toxicity, with the purpose of updating information regarding last researches on this mycotoxin. The most recent studies on the possible methods for preventing Fusarium spp. growth and NIV production are also discussed. Recently, various environmental factors have been shown to influence strongly NIV occurrence. However, Fusarium spp. of the NIV genotype have been found almost worldwide. With regard to NIV cytotoxicity, NIV has been reported to cause a marked decrease in cell proliferation in dif…
Role of the Netrin-like Domain of Procollagen C-Proteinase Enhancer-1 in the Control of Metalloproteinase Activity
2010
The netrin-like (NTR) domain is a feature of several extracellular proteins, most notably the N-terminal domain of tissue inhibitors of metalloproteinases (TIMPs), where it functions as a strong inhibitor of matrix metalloproteinases and some other members of the metzincin superfamily. The presence of a C-terminal NTR domain in procollagen C-proteinase enhancers (PCPEs), proteins that stimulate the activity of astacin-like tolloid proteinases, raises the possibility that this might also have inhibitory activity. Here we show that both long and short forms of the PCPE-1 NTR domain, the latter beginning at the N-terminal cysteine known to be critical for TIMP activity, show no inhibition, at …
Women in Aeschylean scene: a linguistic characterization
2021
Este trabalho examina os dispositivos linguísticos por meio dos quais Ésquilo conseguiu apresentar as personagens femininas da Oresteia. A análise é feita após um levantamento das seções recitativas de três tragédias; características fonéticas, morfológicas e sintáticas foram estudadas e comparadas com a linguagem dos personagens masculinos. Os resultados desta pesquisa se ajustam a outras tentativas precedentes de mostrar como a sociolinguística pode explicar o retrato formal dos personagens trágicos e cômicos. This paper examines the linguistic devices by means of which Aeschylus achieved the presentation of the female characters of the Oresteia. The analysis is made after a survey of the…
DNA damage by bromate: Mechanism and consequences
2005
Abstract Exposure of mammalian cells to bromate (BrO3−) generates oxidative DNA modifications, in particular 7,8-dihydro-8-oxo-guanine (8-oxoG). The damaging mechanism is quite unique, since glutathione, which is protective against most oxidants and alkylating agents, mediates a metabolic activation, while bromate itself does not react directly with DNA. Neither enzymes nor transition metals are required as catalysts in the activation. The ultimate DNA damaging species has not yet been established, but experiments under cell-free conditions suggest that neither molecular bromine nor reactive oxygen species such as superoxide, hydrogen peroxide or singlet oxygen are involved. Rather bromine …
Exposure to patulin from consumption of apple-based products.
2007
Patulin is a mycotoxin produced by species of Penicillium, Aspergillus and Byssochylamys. Several Scientific Committees classify patulin as mutagenic, embryotoxic and immunotoxic. It has been found as a natural contaminant of processed apple products and its presence may be indicative of the quality of fruit used in production. In this work, a method for the analysis of patulin is described, based on a simple liquid-liquid extraction with acetonitrile; patulin is analyzed using liquid chromatography with UV detection. Patulin identity was confirmed by GC-MS after its reaction with N-methyl-N-(trimethylsilyl)trifluoroacetamide. Fifty-three apple-containing products were analyzed and patulin …