Genotoxicity of 1,3-dichloro-2-propanol in the SOS chromotest and in the Ames test. Elucidation of the genotoxic mechanism.

Science.gov (United States)

Hahn, H; Eder, E; Deininger, C

1991-01-01

1,3-Dichloro-2-propanol (1,3-DCP-OH, glycerol dichlorohydrin) is of great importance in many industrial processes and has been detected in foodstuffs, in particular in soup spices and instant soups. It has been shown to be carcinogenic, genotoxic and mutagenic. Its genotoxic mechanisms are, however, not yet entirely understood. We have investigated whether alcohol dehydrogenase (ADH) catalysed activation to the highly mutagenic and carcinogenic 1,3-dichloroacetone or formation of epichlorohydrin or other genotoxic compounds play a role for mutagenicity and genotoxicity. In our studies, no indications of ADH catalysed formation of 1,3-dichloropropane could be found, although we could demonstrate a clear activation by ADH in the case of 2-chloropropenol. Formation of allyl chloride could also be excluded. We found, however, clear evidence that epichlorohydrin formed chemically in the buffer and medium used in the test is responsible for genotoxicity. No indication was found that enzymatic formation of epichlorohydrin plays a role. Additional mutagenicity and genotoxicity studies with epichlorohydrin also confirmed the hypothesis that genotoxic effects of 1,3-DCP-OH depend on the chemical formation of epichlorohydrin.

Brain imaging with 123I-IMP-SPECT in migraine between attacks

International Nuclear Information System (INIS)

Schlake, H.P.; Boettger, I.G.G.; Grotemeyer, K.H.; Husstedt, I.W.

1989-01-01

123 I-IMP-SPECT brain imaging was performed in patients with classic migraine (n = 5) and migraine accompagnee (n = 18) during the headache-free interval. A regional reduction of tracer uptake into brain was observed in all patients with migraine accompagnee, while in patients with classic migraine only one case showed an area of decreased activity. The most marked alteration was found in a patient with persisting neurological symptoms (complicated migraine). In most cases the areas of decreased tracer uptake corresponded to headache localization as well as to topography of neurologic symptoms during migraine attacks. It may be concluded that migraine attacks occur in connection with exacerbations of preexisting changes of cerebral autoregulation due to endogenous or exogenous factors

In vitro genotoxicity assessment of MTES, GPTES and TEOS, three precursors intended for use in food contact coatings.

Science.gov (United States)

Lionti, Krystelle; Séverin, Isabelle; Dahbi, Laurence; Toury, Bérangère; Chagnon, Marie-Christine

2014-03-01

Organoalkoxysilanes are precursors that are used increasingly in the synthesis of food contact coatings. To comply with the EU regulation, their potential toxicity must be assessed, and very little information is known. The genotoxicity of three common precursors was studied, namely, tetraethylorthosilicate (TEOS), methyltriethoxysilane (MTES) and 3-glycidyloxypropyltriethoxysilane (GPTES). By the Ames test, MTES and TEOS were not mutagenic for bacteria. A significant positive response was observed with GPTES in the TA100 and TA1535 strains. The mutagenic effect was more pronounced in the presence of the exogenous metabolic activation system with an increase of the induction factor (ten-fold higher for the TA1535 strain). In the micronucleus assay performed with a human hepatoma cell line (HepG2 cells), GPTES gave negative results even in the presence of an exogenous activation system. To ascertain the possibility of using this precursor in food contact material, its migration must be monitored according to the coating formulation because migration might result in hazardous human exposure. Copyright © 2014. Published by Elsevier Ltd.

Genotoxic consequences of endogenous aldehydes on mouse haematopoietic stem cell function.

Science.gov (United States)

Garaycoechea, Juan I; Crossan, Gerry P; Langevin, Frederic; Daly, Maria; Arends, Mark J; Patel, Ketan J

2012-09-27

Haematopoietic stem cells (HSCs) regenerate blood cells throughout the lifespan of an organism. With age, the functional quality of HSCs declines, partly owing to the accumulation of damaged DNA. However, the factors that damage DNA and the protective mechanisms that operate in these cells are poorly understood. We have recently shown that the Fanconi anaemia DNA-repair pathway counteracts the genotoxic effects of reactive aldehydes. Mice with combined inactivation of aldehyde catabolism (through Aldh2 knockout) and the Fanconi anaemia DNA-repair pathway (Fancd2 knockout) display developmental defects, a predisposition to leukaemia, and are susceptible to the toxic effects of ethanol-an exogenous source of acetaldehyde. Here we report that aged Aldh2(-/-) Fancd2(-/-) mutant mice that do not develop leukaemia spontaneously develop aplastic anaemia, with the concomitant accumulation of damaged DNA within the haematopoietic stem and progenitor cell (HSPC) pool. Unexpectedly, we find that only HSPCs, and not more mature blood precursors, require Aldh2 for protection against acetaldehyde toxicity. Additionally, the aldehyde-oxidizing activity of HSPCs, as measured by Aldefluor stain, is due to Aldh2 and correlates with this protection. Finally, there is more than a 600-fold reduction in the HSC pool of mice deficient in both Fanconi anaemia pathway-mediated DNA repair and acetaldehyde detoxification. Therefore, the emergence of bone marrow failure in Fanconi anaemia is probably due to aldehyde-mediated genotoxicity restricted to the HSPC pool. These findings identify a new link between endogenous reactive metabolites and DNA damage in HSCs, and define the protective mechanisms that counteract this threat.

In silico prediction of genotoxicity.

Science.gov (United States)

Wichard, Jörg D

2017-08-01

The in silico prediction of genotoxicity has made considerable progress during the last years. The main driver for the pharmaceutical industry is the ICH M7 guideline about the assessment of DNA reactive impurities. An important component of this guideline is the use of in silico models as an alternative approach to experimental testing. The in silico prediction of genotoxicity provides an established and accepted method that defines the first step in the assessment of DNA reactive impurities. This was made possible by the growing amount of reliable Ames screening data, the attempts to understand the activity pathways and the subsequent development of computer-based prediction systems. This paper gives an overview of how the in silico prediction of genotoxicity is performed under the ICH M7 guideline. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantitative genotoxicity assays for analysis of medicinal plants: A systematic review.

Science.gov (United States)

Sponchiado, Graziela; Adam, Mônica Lucia; Silva, Caroline Dadalt; Soley, Bruna Silva; de Mello-Sampayo, Cristina; Cabrini, Daniela Almeida; Correr, Cassyano Januário; Otuki, Michel Fleith

2016-02-03

Medicinal plants are known to contain numerous biologically active compounds, and although they have proven pharmacological properties, they can cause harm, including DNA damage. Review the literature to evaluate the genotoxicity risk of medicinal plants, explore the genotoxicity assays most used and compare these to the current legal requirements. A quantitative systematic review of the literature, using the keywords "medicinal plants", "genotoxicity" and "mutagenicity", was undertakenQ to identify the types of assays most used to assess genotoxicity, and to evaluate the genotoxicity potential of medicinal plant extracts. The database searches retrieved 2289 records, 458 of which met the inclusion criteria. Evaluation of the selected articles showed a total of 24 different assays used for an assessment of medicinal plant extract genotoxicity. More than a quarter of those studies (28.4%) reported positive results for genotoxicity. This review demonstrates that a range of genotoxicity assay methods are used to evaluate the genotoxicity potential of medicinal plant extracts. The most used methods are those recommended by regulatory agencies. However, based on the current findings, in order to conduct a thorough study concerning the possible genotoxic effects of a medicinal plant, we indicate that it is important always to include bacterial and mammalian tests, with at least one in vivo assay. Also, these tests should be capable of detecting outcomes that include mutation induction, clastogenic and aneugenic effects, and structural chromosome abnormalities. In addition, the considerable rate of positive results detected in this analysis further supports the relevance of assessing the genotoxicity potential of medicinal plants. Copyright © 2016. Published by Elsevier Ireland Ltd.

"Aspartame: A review of genotoxicity data".

Science.gov (United States)

Kirkland, David; Gatehouse, David

2015-10-01

Aspartame is a methyl ester of a dipeptide of aspartic acid and phenylalanine. It is 200× sweeter than sucrose and is approved for use in food products in more than 90 countries around the world. Aspartame has been evaluated for genotoxic effects in microbial, cell culture and animal models, and has been subjected to a number of carcinogenicity studies. The in vitro and in vivo genotoxicity data available on aspartame are considered sufficient for a thorough evaluation. There is no evidence of induction of gene mutations in a series of bacterial mutation tests. There is some evidence of induction of chromosomal damage in vitro, but this may be an indirect consequence of cytotoxicity. The weight of evidence from in vivo bone marrow micronucleus, chromosomal aberration and Comet assays is that aspartame is not genotoxic in somatic cells in vivo. The results of germ cell assays are difficult to evaluate considering limited data available and deviations from standard protocols. The available data therefore support the conclusions of the European Food Safety Authority (EFSA) that aspartame is non-genotoxic. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

GENOTOXICITY OF TOBACCO SMOKE AND TOBACCO SMOKE CONDENSATE: A REVIEW

Science.gov (United States)

Genotoxicity of Tobacco Smoke and Tobacco Smoke Condensate: A ReviewAbstractThis report reviews the literature on the genotoxicity of main-stream tobacco smoke and cigarette smoke condensate (CSC) published since 1985. CSC is genotoxic in nearly all systems in which it h...

Genotoxic effect of alkaloids

Directory of Open Access Journals (Sweden)

J. A. P. Henriques

1991-01-01

Full Text Available Because of the increase use of alkaloids in general medical practice in recent years, it is of interest to determine genotoxic, mutagenic and recombinogenic response to different groups of alkaloids in prokaryotic and eucaryotic organisms. Reserpine, boldine and chelerythrine did not show genotoxicity response in the SOS-Chromotest whereas skimmianine showed genotixicity in the presence of a metabolic activation mixture. Voacristine isolated fromthe leaves of Ervatamia coronaria shows in vivo cytostatic and mutagenic effects in Saccharomyces cerevisiae hapioids cells. The Rauwolfia alkaloid (reserpine was not able to induce reverse mutation and recombinational mitotic events (crossing-over and gene conversion in yeast diploid strain XS2316.

Exogenous deposits

International Nuclear Information System (INIS)

Khasanov, A.Kh.

1988-01-01

Exogenous deposits forming as a result of complex exogenous processes, passed under the influence of outside forces on the Earth surface. To them relate physical and chemical weathering, decomposition and decay of mineral masses, redistribution and transportation of material, forming and deposit of new minerals and ores steady on the earth surface conditions

Genotoxicity risk assessment of diversely substituted quinolines using the SOS chromotest.

Science.gov (United States)

Duran, Leidy Tatiana Díaz; Rincón, Nathalia Olivar; Galvis, Carlos Eduardo Puerto; Kouznetsov, Vladimir V; Lorenzo, Jorge Luis Fuentes

2015-03-01

Quinolines are aromatic nitrogen compounds with wide therapeutic potential to treat parasitic and microbial diseases. In this study, the genotoxicity of quinoline, 4-methylquinoline, 4-nitroquinoline-1-oxide (4-NQO), and diversely functionalized quinoline derivatives and the influence of the substituents (functional groups and/or atoms) on their genotoxicity were tested using the SOS chromotest. Quinoline derivatives that induce genotoxicity by the formation of an enamine epoxide structure did not induce the SOS response in Escherichia coli PQ37 cells, with the exception of 4-methylquinoline that was weakly genotoxic. The chemical nature of the substitution (C-5 to C-8: hydroxyl, nitro, methyl, isopropyl, chlorine, fluorine, and iodine atoms; C-2: phenyl and 3,4-methylenedioxyphenyl rings) of quinoline skeleton did not significantly modify compound genotoxicities; however, C-2 substitution with α-, β-, or γ-pyridinyl groups removed 4-methylquinoline genotoxicity. On the other hand, 4-NQO derivatives whose genotoxic mechanism involves reduction of the C-4 nitro group were strong inducers of the SOS response. Methyl and nitrophenyl substituents at C-2 of 4-NQO core affected the genotoxic potency of this molecule. The relevance of these results is discussed in relation to the potential use of the substituted quinolines. The work showed the sensitivity of SOS chromotest for studying structure-genotoxicity relationships and bioassay-guided quinoline synthesis. © 2013 Wiley Periodicals, Inc.

Lack of genotoxicity in vivo for food color additive Tartrazine.

Science.gov (United States)

Bastaki, Maria; Farrell, Thomas; Bhusari, Sachin; Pant, Kamala; Kulkarni, Rohan

2017-07-01

Tartrazine is approved as a food color additive internationally with INS number 102, in the United States as food color subject to batch certification "Food, Drug, and Cosmetic" (FD&C) Yellow No. 5, and in Europe as food color additive with E number 102. In their evaluation of the color (2013), the European Food Safety Authority (EFSA) expressed concerns of potential genotoxicity, based primarily on one genotoxicity study that was not conducted according to Guidelines. The present in vivo genotoxicity study was conducted according to OECD Guidelines in response to EFSA's request for additional data. The animal species and strain, and the tissues examined were selected specifically to address the previously reported findings. The results of this study show clear absence of genotoxic activity for Tartrazine, in the bone marrow micronucleus assay and the Comet assay in the liver, stomach, and colon. These data addressed EFSA's concerns for genotoxicity. The Joint WHO/FAO Committee on Food Additives (JECFA) (2016) also reviewed these data and concluded that there is no genotoxicity concern for Tartrazine. Negative findings in parallel genotoxicity studies on Allura Red AC and Ponceau 4R (published separately) are consistent with lack of genotoxicity for azo dyes used as food colors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pyruvate remediation of cell stress and genotoxicity induced by haloacetic acid drinking water disinfection by-products.

Science.gov (United States)

Dad, Azra; Jeong, Clara H; Pals, Justin A; Wagner, Elizabeth D; Plewa, Michael J

2013-10-01

Monohaloacetic acids (monoHAAs) are a major class of drinking water disinfection by-products (DBPs) and are cytotoxic, genotoxic, mutagenic, and teratogenic. We propose a model of toxic action based on monoHAA-mediated inhibition of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a target cytosolic enzyme. This model predicts that GAPDH inhibition by the monoHAAs will lead to a severe reduction of cellular ATP levels and repress the generation of pyruvate. A loss of pyruvate will lead to mitochondrial stress and genomic DNA damage. We found a concentration-dependent reduction of ATP in Chinese hamster ovary cells after monoHAA treatment. ATP reduction per pmol monoHAA followed the pattern of iodoacetic acid (IAA) > bromoacetic acid (BAA) > chloroacetic acid (CAA), which is the pattern of potency observed with many toxicological endpoints. Exogenous supplementation with pyruvate enhanced ATP levels and attenuated monoHAA-induced genomic DNA damage as measured with single cell gel electrophoresis. These data were highly correlated with the SN 2 alkylating potentials of the monoHAAs and with the induction of toxicity. The results from this study strongly support the hypothesis that GAPDH inhibition and the possible subsequent generation of reactive oxygen species is linked with the cytotoxicity, genotoxicity, teratogenicity, and neurotoxicity of these DBPs. Copyright © 2013 Wiley Periodicals, Inc.

Is Money Really Exogenous? Testing for Weak Exogeneity in Swiss Money Demand.

OpenAIRE

Fischer, Andreas M

1993-01-01

Although exogeneity is often associated with controllable policy variables, Engle, Hendry, and Richard (1983) show that the one condition is neither necessary nor sufficient for the other. Whether variables such as monetary aggregates are (weakly) exogenous depends on the conditioning properties of the data generating process. Testing exogeneity claims represents an important step in analyzing money demand functions. Although Switzerland adheres to fairly strict monetarist prescriptions, we r...

SIGNALING TO THE P53 TUMOR SUPPRESSOR THROUGH PATHWAYS ACTIVATED BY GENOTOXIC AND NON-GENOTOXIC STRESSES.

Energy Technology Data Exchange (ETDEWEB)

ANDERSON,C.W.APPELLA,E.

2002-07-01

The p53 tumor suppressor is a tetrameric transcription factor that is post-translational modified at {approx}18 different sites by phosphorylation, acetylation, or sumoylation in response to various cellular stress conditions. Specific posttranslational modifications, or groups of modifications, that result from the activation of different stress-induced signaling pathways are thought to modulate p53 activity to regulate cell fate by inducing cell cycle arrest, apoptosis, or cellular senescence. Here we review the posttranslational modifications to p53 and the pathways that produce them in response to both genotoxic and non-genotoxic stresses.

Assessment of mutagenic, antimutagenic and genotoxicity effects of Mimosa tenuiflora

Directory of Open Access Journals (Sweden)

Viviane A. Silva

2013-02-01

Full Text Available Genotoxic effects of Mimosa tenuiflora (Willd. Poir, Fabaceae, were investigated by using both micronucleus test and bacterial reverse mutation assay in Salmonella typhimurium TA97, TA98, TA100, TA102 respectively. In respect of Ames test results show that the extract does not induce mutations in any strains of Salmonella typhimurium tested since the mutagenicity index is less than 2. In the antimutagenic effect was observed that the extract at the concentrations tested significantly decreased the mutagenicity index of all strains tested which characterized the extract as antimutagenic in these conditions. In the micronucleus test in vivo, we observed that the concentrations used did not induce an increase in the frequency of micronucleus in normochromatic erythrocytes of mice. Therefore, we concluded that the extract of M. tenuiflora is not mutagenic in the absence of exogenous metabolizing system and does not induce an increase in the frequency of the micronucleus characterized as an agent not mutagenic in these conditions. Further studies of toxicity need to be made to the use of this plant in the treatment of diseases to be stimulated.

Assessment of mutagenic, antimutagenic and genotoxicity effects of Mimosa tenuiflora

Directory of Open Access Journals (Sweden)

Viviane A. Silva

2013-04-01

Full Text Available Genotoxic effects of Mimosa tenuiflora (Willd. Poir, Fabaceae, were investigated by using both micronucleus test and bacterial reverse mutation assay in Salmonella typhimurium TA97, TA98, TA100, TA102 respectively. In respect of Ames test results show that the extract does not induce mutations in any strains of Salmonella typhimurium tested since the mutagenicity index is less than 2. In the antimutagenic effect was observed that the extract at the concentrations tested significantly decreased the mutagenicity index of all strains tested which characterized the extract as antimutagenic in these conditions. In the micronucleus test in vivo, we observed that the concentrations used did not induce an increase in the frequency of micronucleus in normochromatic erythrocytes of mice. Therefore, we concluded that the extract of M. tenuiflora is not mutagenic in the absence of exogenous metabolizing system and does not induce an increase in the frequency of the micronucleus characterized as an agent not mutagenic in these conditions. Further studies of toxicity need to be made to the use of this plant in the treatment of diseases to be stimulated.

Exogenous Salicylic Acid Enhances the Resistance of Wheat Seedlings to Hessian Fly (Diptera: Cecidomyiidae) Infestation Under Heat Stress.

Science.gov (United States)

Underwood, Joshua; Moch, John; Chen, Ming-Shun; Zhu, Lieceng

2014-10-01

Heat stress exerts significant impact on plant-parasite interactions. Phytohormones, such as salicylic acid (SA), play important roles in plant defense against parasite attacks. Here, we studied the impact of a combination of heat stress and exogenous SA on the resistance of wheat (Triticum aestivum L.) plants to the Hessian fly [Mayetiola destructor (Say)]. We found that the wheat cultivar 'Molly', which contains the resistance gene H13, lost resistance to Hessian fly under heat stress (40°C for 3 and 6 h), and that exogenous application of SA on Molly seedlings right before heat stress can partially prevent the loss of resistance of Molly plants under heat conditions. Our findings have significant implications for understanding the dynamics of plant-insect interactions in the context of heat stress. © 2014 Entomological Society of America.

Genotoxicity of 2-bromo-3′-chloropropiophenone

Energy Technology Data Exchange (ETDEWEB)

Meng, Fanxue; Yan, Jian; Li, Yan [Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079 (United States); Fu, Peter P. [Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079 (United States); Fossom, Linda H.; Sood, Ramesh K.; Mans, Daniel J.; Chu, Pei-I [Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993 (United States); Moore, Martha M. [Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079 (United States); Chen, Tao, E-mail: tao.chen@fda.hhs.gov [Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079 (United States)

2013-07-15

Impurities are present in any drug substance or drug product. They can be process-related impurities that are not completely removed during purification or are formed due to the degradation of the drug substance over the product shelf-life. Unlike the drug substance, impurities generally do not have beneficial effects and may present a risk without associated benefit. Therefore, their amount should be minimized. 2-Bromo-3′-chloropropiophenone (BCP) is an impurity of bupropion, a second-generation antidepressant and a smoking cessation aid. The United States Pharmacopeia recommends an acceptable level for BCP that is not more than 0.1% of the bupropion. Because exposure to genotoxic impurities even at low levels is of significant concern, it is important to determine whether or not BCP is genotoxic. Therefore, in this study the Ames test and the in vitro micronucleus assay were conducted to evaluate the genotoxicity of BCP. BCP was mutagenic with S9 metabolic activation, increasing the mutant frequencies in a concentration-dependent manner, up to 22- and 145-fold induction over the controls in Salmonella strains TA100 and TA1535, respectively. BCP was also positive in the in vitro micronucleus assay, resulting in up to 3.3- and 5.1-fold increase of micronucleus frequency for treatments in the absence and presence of S9, respectively; and 9.9- and 7.4-fold increase of aneuploidies without and with S9, respectively. The addition of N-acetyl-L-cysteine, an antioxidant, reduced the genotoxicity of BCP in both assays. Further studies showed that BCP treatment resulted in induction of reactive oxygen species (ROS) in the TK6 cells. The results suggest that BCP is mutagenic, clastogenic, and aneugenic, and that these activities are mediated via generation of reactive metabolites. - Highlights: • 2-Bromo-3′-chloropropiophenone is an impurity of bupropion. • BCP was positive in both the Ames test and the in vitro micronucleus assay. • It induced high frequencies of

Genotoxicity of 2-bromo-3′-chloropropiophenone

International Nuclear Information System (INIS)

Meng, Fanxue; Yan, Jian; Li, Yan; Fu, Peter P.; Fossom, Linda H.; Sood, Ramesh K.; Mans, Daniel J.; Chu, Pei-I; Moore, Martha M.; Chen, Tao

2013-01-01

Impurities are present in any drug substance or drug product. They can be process-related impurities that are not completely removed during purification or are formed due to the degradation of the drug substance over the product shelf-life. Unlike the drug substance, impurities generally do not have beneficial effects and may present a risk without associated benefit. Therefore, their amount should be minimized. 2-Bromo-3′-chloropropiophenone (BCP) is an impurity of bupropion, a second-generation antidepressant and a smoking cessation aid. The United States Pharmacopeia recommends an acceptable level for BCP that is not more than 0.1% of the bupropion. Because exposure to genotoxic impurities even at low levels is of significant concern, it is important to determine whether or not BCP is genotoxic. Therefore, in this study the Ames test and the in vitro micronucleus assay were conducted to evaluate the genotoxicity of BCP. BCP was mutagenic with S9 metabolic activation, increasing the mutant frequencies in a concentration-dependent manner, up to 22- and 145-fold induction over the controls in Salmonella strains TA100 and TA1535, respectively. BCP was also positive in the in vitro micronucleus assay, resulting in up to 3.3- and 5.1-fold increase of micronucleus frequency for treatments in the absence and presence of S9, respectively; and 9.9- and 7.4-fold increase of aneuploidies without and with S9, respectively. The addition of N-acetyl-L-cysteine, an antioxidant, reduced the genotoxicity of BCP in both assays. Further studies showed that BCP treatment resulted in induction of reactive oxygen species (ROS) in the TK6 cells. The results suggest that BCP is mutagenic, clastogenic, and aneugenic, and that these activities are mediated via generation of reactive metabolites. - Highlights: • 2-Bromo-3′-chloropropiophenone is an impurity of bupropion. • BCP was positive in both the Ames test and the in vitro micronucleus assay. • It induced high frequencies of

Recent perspectives on the relations between faecal mutagenicity, genotoxicity and diet

Directory of Open Access Journals (Sweden)

Silvia eGratz

2011-03-01

Full Text Available DNA damage is an essential component of the genesis of colonic cancer. Gut microbial products and food components are thought to be principally responsible for the damage that initiates disease progression. Modified Ames tests and Comet assays have been developed for measuring mutagenicity and genotoxicity. Their relevance to oncogenesis remains to be confirmed, as does the relative importance of different mutagenic and genotoxic compounds present in faecal water and the bacteria involved in their metabolism. Dietary intervention studies provide clues to the likely risks of oncogenesis. High-protein diets lead to increases in N-nitroso compounds in faecal water and greater DNA damage as measured by the Comet assay, for example. Other dietary interventions, such as non-digestible carbohydrates and probiotics, may lead to lower faecal genotoxicity. In order to make recommendations to the general public, we must develop a better understanding of how genotoxic compounds are formed in the colon, how accurate the Ames and Comet assays are, and how diet affects genotoxicity.

The genotoxic contribution of wood smoke to indoor respirable suspended particles

Energy Technology Data Exchange (ETDEWEB)

Boone, P.M. (John B. Pierce Foundation Laboratory, New Haven, CT (USA)); Rossman, T.G. (New York Univ. Medical Center, New York (USA)); Daisey, J.M. (Lawrence Berkeley Laboratory, CA (USA))

1989-01-01

The effect of wood burning stoves on the genotoxicity of indoor respirable organic matter was investigated for four homes during the winter and spring of 1986. Paired samples, one collected when the stove was not used and one when wood was burned, were extracted with dichloromethane and acetone. Aliquots of the dichloromethane extracts were analyzed with and without metabolic activation using the Microscreen bioassay. The Microscreen is a rapid, sensitive bioassay which measures a broad genotoxic endpoint, {lambda}-prophage induction. Per nanogram of organic material, wood smoke proved to be a major source of indirect (observed with metabolic activation) but not direct genotoxins in homes. The increase in indirect genotoxicity for extracts from aerosol containing wood smoke is probably due to higher concentrations of polycyclic aromatic hydrocarbons in the wood smoke aerosol as well as other unidentified classes. The direct genotoxicity observed for extracts of aerosol not containing wood smoke decreased with metabolic activation. This direct genotoxicity may be related to cooking activities in the homes. The trends in genotoxicity observed per nanogram of organic material are more pronounced when expressed per m{sup 3} of air due to the higher percentage of extractable material in aerosol containing wood smoke.

METABOLISM, GENOTOXICITY, AND CARCINOGENICITY OF COMFREY

Science.gov (United States)

Mei, Nan; Guo, Lei; Fu, Peter P.; Fuscoe, James C.; Luan, Yang; Chen, Tao

2018-01-01

Comfrey has been consumed by humans as a vegetable and a tea and used as an herbal medicine for more than 2000 years. Comfrey, however, produces hepatotoxicity in livestock and humans and carcinogenicity in experimental animals. Comfrey contains as many as 14 pyrrolizidine alkaloids (PA), including 7-acetylintermedine, 7-acetyllycopsamine, echimidine, intermedine, lasiocarpine, lycopsamine, myoscorpine, symlandine, symphytine, and symviridine. The mechanisms underlying comfrey-induced genotoxicity and carcinogenicity are still not fully understood. The available evidence suggests that the active metabolites of PA in comfrey interact with DNA in liver endothelial cells and hepatocytes, resulting in DNA damage, mutation induction, and cancer development. Genotoxicities attributed to comfrey and riddelliine (a representative genotoxic PA and a proven rodent mutagen and carcinogen) are discussed in this review. Both of these compounds induced similar profiles of 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-derived DNA adducts and similar mutation spectra. Further, the two agents share common mechanisms of drug metabolism and carcinogenesis. Overall, comfrey is mutagenic in liver, and PA contained in comfrey appear to be responsible for comfrey-induced toxicity and tumor induction. PMID:21170807

Metabolism, genotoxicity, and carcinogenicity of comfrey.

Science.gov (United States)

Mei, Nan; Guo, Lei; Fu, Peter P; Fuscoe, James C; Luan, Yang; Chen, Tao

2010-10-01

Comfrey has been consumed by humans as a vegetable and a tea and used as an herbal medicine for more than 2000 years. Comfrey, however, produces hepatotoxicity in livestock and humans and carcinogenicity in experimental animals. Comfrey contains as many as 14 pyrrolizidine alkaloids (PA), including 7-acetylintermedine, 7-acetyllycopsamine, echimidine, intermedine, lasiocarpine, lycopsamine, myoscorpine, symlandine, symphytine, and symviridine. The mechanisms underlying comfrey-induced genotoxicity and carcinogenicity are still not fully understood. The available evidence suggests that the active metabolites of PA in comfrey interact with DNA in liver endothelial cells and hepatocytes, resulting in DNA damage, mutation induction, and cancer development. Genotoxicities attributed to comfrey and riddelliine (a representative genotoxic PA and a proven rodent mutagen and carcinogen) are discussed in this review. Both of these compounds induced similar profiles of 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-derived DNA adducts and similar mutation spectra. Further, the two agents share common mechanisms of drug metabolism and carcinogenesis. Overall, comfrey is mutagenic in liver, and PA contained in comfrey appear to be responsible for comfrey-induced toxicity and tumor induction.

Hepatotoxicity and genotoxicity of gasoline fumes in albino rats

Directory of Open Access Journals (Sweden)

Folarin O. Owagboriaye

2017-09-01

Full Text Available Toxic effects of gasoline fumes have been reported, but evidence of its hepatotoxicity and genotoxicity are rare. Therefore, this study assesses hepatotoxicity and genotoxicity of gasoline fumes on forty Albino rats randomly assigned to five experimental treatments (T with eight rats per treatment (T1, T2, T3, T4 and T5. T1(Control was housed in a section of experimental animal house free from gasoline fumes while T2, T3, T4 and T5 were exposed to gasoline fumes in exposure chambers for one, three, five and nine hours daily respectively for twelve weeks. Serum alanine aminotransferase (ALT, aspartate aminotransferase (AST, alkaline phosphatase (ALP and histopathological examination of the liver tissues were used as diagnostic markers to assess liver dysfunction. Genotoxicity test was conducted on the lung tissues using randomly amplified polymorphic DNA fingerprinting polymerase chain reaction (RAPD PCR technique. Significant increase (p < 0.05 in the level of ALT, AST and ALP for T2, T3, T4 and T5 compared to T1 were recorded. Photomicrograph examination of the liver sections of T1 showed hepatic tissue with normal liver cell architecture while that of T2, T3, T4 and T5 revealed degenerative changes in the ultrastructural integrity of the hepatic cells. Genotoxicity test revealed DNA bands at a reducing intensity from T1 to T5. Dendrogram showed DNA damage in the lungs of T3, T4 and T5 were closely similar and the genotoxic impact was more in T3. Frequent exposure to gasoline fumes was observed to induce hepatoxicity and genotoxicity, hence impairing the normal liver function and gene structure.

Current investigations into the genotoxicity of zinc oxide and silica nanoparticles in mammalian models in vitro and in vivo: carcinogenic/genotoxic potential, relevant mechanisms and biomarkers, artifacts, and limitations

Directory of Open Access Journals (Sweden)

Kwon JY

2014-12-01

Full Text Available Jee Young Kwon,1,* Preeyaporn Koedrith,2,* Young Rok Seo1 1Department of Life Science, Institute of Environmental Medicine, Dongguk University, Seoul, Republic of Korea; 2Faculty of Environment and Resource Studies, Mahidol University, Phuttamonthon District, NakhonPathom, Thailand *These authors contributed equally to this work and should be considered as co-first authors Abstract: Engineered nanoparticles (NPs are widely used in many sectors, such as food, medicine, military, and sport, but their unique characteristics may cause deleterious health effects. Close attention is being paid to metal NP genotoxicity; however, NP genotoxic/carcinogenic effects and the underlying mechanisms remain to be elucidated. In this review, we address some metal and metal oxide NPs of interest and current genotoxicity tests in vitro and in vivo. Metal NPs can cause DNA damage such as chromosomal aberrations, DNA strand breaks, oxidative DNA damage, and mutations. We also discuss several parameters that may affect genotoxic response, including physicochemical properties, widely used assays/end point tests, and experimental conditions. Although potential biomarkers of nanogenotoxicity or carcinogenicity are suggested, inconsistent findings in the literature render results inconclusive due to a variety of factors. Advantages and limitations related to different methods for investigating genotoxicity are described, and future directions and recommendations for better understanding genotoxic potential are addressed. Keywords: carcinogenicity, exposure assessment, genotoxicity, nanoparticles, risk evaluation

Assessment of Genotoxicity of Ionizing radiation using Tradescantia-Comet assay

Energy Technology Data Exchange (ETDEWEB)

Han, Min; Ryu, Tae Ho; Hyun, Kyung Man; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Wilhelmova, Nad [Institute of Experimental Botany, Prague (Czech Republic)

2010-05-15

Over the last two decades, several new methodologies for the detection of DNA damage have been developed. The comet assay is currently used in different areas of biological sciences to detect DNA damage. The comet assay, also called the single cell gel electrophoresis (SCGE) was first introduced by Ostling and Johanson as a microelectrophoretic technique for the direct visualization of DNA damage in individual cells. The comet assay, due to its simplicity, sensitivity and need of a few cells, is ideal as a short-term genotoxicity test. The comet assay can theoretically be applied to every type of eukaryotic cell, including plant cells. Plants are very useful as monitors of genetic effects caused by pollution in the atmosphere, water and soil. Although the genotoxic effects detected by Tradescantia tests cannot be associated with mutagenesis or even carcinogenesis in humans, these bioassays are very useful tools for screening the mutagenic potential in the environment. Experiments were conducted to study the genotoxic effects of ionizing radiations on the genome integrity, particularly of Tradescantia. The increasingly frequent use of Tradescantia as a sensitive environmental bioindicator of genotoxic effects. This study was designed to assess the genotoxicity of ionizing radiation using Tradescnatia-comet assay

Exogenous fatty acid metabolism in bacteria.

Science.gov (United States)

Yao, Jiangwei; Rock, Charles O

2017-10-01

Bacterial type II fatty acid synthesis (FASII) is a target for novel antibiotic development. All bacteria encode for mechanisms to incorporate exogenous fatty acids, and some bacteria can use exogenous fatty acids to bypass FASII inhibition. Bacteria encode three different mechanisms for activating exogenous fatty acids for incorporation into phospholipid synthesis. Exogenous fatty acids are converted into acyl-CoA in Gammaproteobacteria such as E. coli. Acyl-CoA molecules constitute a separate pool from endogenously synthesized acyl-ACP. Acyl-CoA can be used for phospholipid synthesis or broken down by β-oxidation, but cannot be used for lipopolysaccharide synthesis. Exogenous fatty acids are converted into acyl-ACP in some Gram-negative bacteria. The resulting acyl-ACP undergoes the same fates as endogenously synthesized acyl-ACP. Exogenous fatty acids are converted into acyl-phosphates in Gram-positive bacteria, and can be used for phospholipid synthesis or become acyl-ACP. Only the order Lactobacillales can use exogenous fatty acids to bypass FASII inhibition. FASII shuts down completely in presence of exogenous fatty acids in Lactobacillales, allowing Lactobacillales to synthesize phospholipids entirely from exogenous fatty acids. Inhibition of FASII cannot be bypassed in other bacteria because FASII is only partially down-regulated in presence of exogenous fatty acid or FASII is required to synthesize essential metabolites such as β-hydroxyacyl-ACP. Certain selective pressures such as FASII inhibition or growth in biofilms can select for naturally occurring one step mutations that attenuate endogenous fatty acid synthesis. Although attempts have been made to estimate the natural prevalence of these mutants, culture-independent metagenomic methods would provide a better estimate. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

The use of ex vivo human skin tissue for genotoxicity testing

Energy Technology Data Exchange (ETDEWEB)

Reus, Astrid A.; Usta, Mustafa [TNO Triskelion BV, Utrechtseweg 48, 3704 HE, Zeist (Netherlands); Krul, Cyrille A.M., E-mail: cyrille.krul@tno.nl [TNO, Utrechtseweg 48, 3704 HE Zeist (Netherlands)

2012-06-01

As a result of the chemical legislation concerning the registration, evaluation, authorization and restriction of chemicals (REACH), and the Seventh Amendment to the Cosmetics Directive, which prohibits animal testing in Europe for cosmetics, alternative methods for safety evaluation of chemicals are urgently needed. Current in vitro genotoxicity assays are not sufficiently predictive for the in vivo situation, resulting in an unacceptably high number of misleading positives. For many chemicals and ingredients of personal care products the skin is the first site of contact, but there are no in vitro genotoxicity assays available in the skin for additional evaluation of positive or equivocal responses observed in regulatory in vitro genotoxicity assays. In the present study ex vivo human skin tissue obtained from surgery was used for genotoxicity evaluation of chemicals by using the comet assay. Fresh ex vivo human skin tissue was cultured in an air–liquid interface and topically exposed to 20 chemicals, including true positive, misleading positive and true negative genotoxins. Based on the results obtained in the present study, the sensitivity, specificity and accuracy of the ex vivo skin comet assay to predict in vivo genotoxicity were 89%, 90% and 89%, respectively. Donor and experimental variability were mainly reflected in the magnitude of the response and not the difference between the presence and absence of a genotoxic response. The present study indicates that human skin obtained from surgery is a promising and robust model for safety evaluation of chemicals that are in direct contact with the skin. -- Highlights: ► We use human skin obtained from surgery for genotoxicity evaluation of chemicals. ► We use the comet assay as parameter for genotoxicity in ex vivo human skin. ► Sensitivity, specificity and accuracy to predict in vivo genotoxins are determined. ► Sensitivity, specificity and accuracy are 89%, 90% and 90%, respectively. ► The method

The use of ex vivo human skin tissue for genotoxicity testing

International Nuclear Information System (INIS)

Reus, Astrid A.; Usta, Mustafa; Krul, Cyrille A.M.

2012-01-01

As a result of the chemical legislation concerning the registration, evaluation, authorization and restriction of chemicals (REACH), and the Seventh Amendment to the Cosmetics Directive, which prohibits animal testing in Europe for cosmetics, alternative methods for safety evaluation of chemicals are urgently needed. Current in vitro genotoxicity assays are not sufficiently predictive for the in vivo situation, resulting in an unacceptably high number of misleading positives. For many chemicals and ingredients of personal care products the skin is the first site of contact, but there are no in vitro genotoxicity assays available in the skin for additional evaluation of positive or equivocal responses observed in regulatory in vitro genotoxicity assays. In the present study ex vivo human skin tissue obtained from surgery was used for genotoxicity evaluation of chemicals by using the comet assay. Fresh ex vivo human skin tissue was cultured in an air–liquid interface and topically exposed to 20 chemicals, including true positive, misleading positive and true negative genotoxins. Based on the results obtained in the present study, the sensitivity, specificity and accuracy of the ex vivo skin comet assay to predict in vivo genotoxicity were 89%, 90% and 89%, respectively. Donor and experimental variability were mainly reflected in the magnitude of the response and not the difference between the presence and absence of a genotoxic response. The present study indicates that human skin obtained from surgery is a promising and robust model for safety evaluation of chemicals that are in direct contact with the skin. -- Highlights: ► We use human skin obtained from surgery for genotoxicity evaluation of chemicals. ► We use the comet assay as parameter for genotoxicity in ex vivo human skin. ► Sensitivity, specificity and accuracy to predict in vivo genotoxins are determined. ► Sensitivity, specificity and accuracy are 89%, 90% and 90%, respectively. ► The method

Genotoxicity and ELF-magnetic fields: a review through the micronucleus assay

International Nuclear Information System (INIS)

Alcaraz, M.; Andreu-Galvez, M.; Sanchez-Villalobos, J. M.; Achel, D. G.; Olmos, E.; Martinez-Hernandez, C. M.

2012-01-01

Thirty for (34) published studies, conducted from 1994 to the present to evaluate the genotoxic effect of magnetic fields using ELF-EMF and diagnostic resonance on humans by the micronucleus assay have been reviewed. some characteristics of the assay methods, their significance to genotoxicity and basic interpretations of the results of these assays are discussed. of the studies analysed 70.5% implicated genotoxic effects induced by these magnetic fields: 52.9% were due to exposure to magnetic fields only and 17,6% by exposure to magnetic fields in combination with some treatment types, resulting in additive or synergistic effect. Evidence exist to support the notion that exposure of humans to magnetic fields stimulates genotoxic effects, although the actual mechanisms of action or even the true human health consequences resulting from these exposure still remain unclear. (Author) 80 refs.

Soil genotoxicity assessment: a new stategy based on biomolecular tools and plant bioindicators.

Science.gov (United States)

Citterio, Sandra; Aina, Roberta; Labra, Massimo; Ghiani, Alessandra; Fumagalli, Pietro; Sgorbati, Sergio; Santagostino, Angela

2002-06-15

The setting up of efficient early warning systems is a challenge to research for preventing environmental alteration and human disease. In this paper, we report the development and the field application of a new biomonitoring methodology for assessing soil genotoxicity. In the first part, the use of amplified fragment length polymorphism and flow cytometry techniques to detect DNA damage induced by soils artificially contaminated with heavy metals as potentially genotoxic compounds is explained. Results show that the combination of the two techniques leads to efficient detection of the sublethal genotoxic effect induced in the plant bioindicator by contaminated soil. By contrast, the classic mortality, root, and shoot growth vegetative endpoints prove inappropriate for assessing soil genotoxicity because, although they cause genotoxic damage, some heavy metals do not affect sentinel plant development negatively. The statistical elaboration of the data obtained led to the development of a statistical predictive model which differentiates four different levels of soil genotoxic pollution and can be used everywhere. The second part deals with the application of the biomonitoring protocol in the genotoxic assessment of two areas surrounding a steelworks in northern Italy and the effectiveness of this methodology. In this particular case, in these areas, the predictive model reveals a pollution level strictly correlated to the heavy metal concentrations revealed by traditional chemical analysis.

Borax counteracts genotoxicity of aluminum in rat liver.

Science.gov (United States)

Turkez, Hasan; Geyikoğlu, Fatime; Tatar, Abdulgani

2013-10-01

This study was carried out to evaluate the protective role of borax (BX) on genotoxicity induced by aluminum (Al) in rat liver, using liver micronucleus assay as an indicator of genotoxicity. Sprague-Dawley rats were randomly separated into six groups and each group had four animals. Aluminum chloride (AlCl₃; 5 mg/kg b.w.) and BX (3.25 and 13 mg/kg b.w.) were injected intraperitoneally to rats. Besides, animals were also treated with Al for 4 consecutive days followed by BX for 10 days. Rats were anesthetized after Al and BX injections and the hepatocytes were isolated for counting the number of micronucleated hepatocytes (MNHEPs). AlCl₃ was found to significantly (p < 0.05) increase the number of MNHEPs. Rats treated with BX, however, showed no increase in MNHEPs. Moreover, simultaneous treatments with BX significantly modulated the genotoxic effects of AlCl₃ in rats. It can be concluded that BX has beneficial influences and has the ability to antagonize Al toxicity.

Genotoxicity evaluation of the insecticide ethion in root of Allium ...

African Journals Online (AJOL)

USER

2010-07-05

Jul 5, 2010 ... In this study, the genotoxic effects of ethion were investigated in the mitotic cell division of Allium ... The use of plant root tips, particularly those of A. cepa and Vicia faba, as a bioassay test system for the genotoxicity of pesticides has shown extremely ..... the long run, even below the recommended dose.

Genotoxicity test of irradiated foods

International Nuclear Information System (INIS)

Tanaka, Noriho

2004-01-01

Safety tests of radiation irradiated foods started as early as from 1967 in Japan and genotoxicity tests in the Hatano Res. Inst., from 1977. The latter is unique in the world and is reviewed in this paper. Tests included those for the initial injury of DNA, mutagenicity, chromosomal aberration and transformation with use of bacteria, cultured mammalian cells and animals (for chromosomal aberration, micronucleus formation and dominant lethality). Foods tested hitherto were onion, rice, wheat and flour, Vienna sausage, fish sausage (kamaboko), mandarian orange, potato, black pepper and red capsicum, of which extract or powder was subjected to the test. Irradiation doses and its purposes were 0.15-6 kGy γ-ray ( 60 Co) or electron beam by the accelerator (only for the orange), and suppression of germination, pesticide action or sterilization, respectively. Genotoxicity of all foods under tested conditions is shown negative. (N.I.)

Screening potential genotoxic effect of aquatic plant extracts using the mussel micronucleus test

Directory of Open Access Journals (Sweden)

Bettina Eck-Varanka

2016-01-01

Full Text Available Objective: To assess the genotoxic potential of selected aquatic macrophytes: Ceratophyllum demersum L. (hornwort, family Ceratophyllaceae, Typha angustifolia L. (narrowleaf cattail, family Typhaceae, Stratiotes aloides L. (water soldier, family Butomaceae, and Oenanthe aquatica (L. Poir. (water dropwort, family Umbelliferae. Methods: For genotoxicity assessment, the mussel micronucleus test was applied. Micronucleus frequency was determined from the haemolymph of Unio pictorum L. (painter’s mussel. In parallel, total and hydrolisable tannin contents were determined. Results: All plant extracts elucidated significant mutagenic effect. Significant correlation was determined between tannin content and mutagenic capacity. Conclusions: The significant correlation between genotoxicity as expressed by micronucleus frequency and tannin content (both total and hydrolisable tannins indicate that tannin is amongst the main compounds being responsible for the genotoxic potential. It might be suggested that genotoxic capacity of these plants elucidate a real ecological effect in the ecosystem.

A whole-cell bioreporter assay for quantitative genotoxicity evaluation of environmental samples.

Science.gov (United States)

Jiang, Bo; Li, Guanghe; Xing, Yi; Zhang, Dayi; Jia, Jianli; Cui, Zhisong; Luan, Xiao; Tang, Hui

2017-10-01

Whole-cell bioreporters have emerged as promising tools for genotoxicity evaluation, due to their rapidity, cost-effectiveness, sensitivity and selectivity. In this study, a method for detecting genotoxicity in environmental samples was developed using the bioluminescent whole-cell bioreporter Escherichia coli recA::luxCDABE. To further test its performance in a real world scenario, the E. coli bioreporter was applied in two cases: i) soil samples collected from chromium(VI) contaminated sites; ii) crude oil contaminated seawater collected after the Jiaozhou Bay oil spill which occurred in 2013. The chromium(VI) contaminated soils were pretreated by water extraction, and directly exposed to the bioreporter in two phases: aqueous soil extraction (water phase) and soil supernatant (solid phase). The results indicated that both extractable and soil particle fixed chromium(VI) were bioavailable to the bioreporter, and the solid-phase contact bioreporter assay provided a more precise evaluation of soil genotoxicity. For crude oil contaminated seawater, the response of the bioreporter clearly illustrated the spatial and time change in genotoxicity surrounding the spill site, suggesting that the crude oil degradation process decreased the genotoxic risk to ecosystem. In addition, the performance of the bioreporter was simulated by a modified cross-regulation gene expression model, which quantitatively described the DNA damage response of the E. coli bioreporter. Accordingly, the bioluminescent response of the bioreporter was calculated as the mitomycin C equivalent, enabling quantitative comparison of genotoxicities between different environmental samples. This bioreporter assay provides a rapid and sensitive screening tool for direct genotoxicity assessment of environmental samples. Copyright © 2017. Published by Elsevier Ltd.

Mutagenicity and genotoxicity of coal fly ash water leachate.

Science.gov (United States)

Chakraborty, Rajarshi; Mukherjee, Anita

2009-03-01

Fly ash is a by-product of coal-fired electricity generation plants. The prevalent practice of disposal is as slurry of ash and water to storage or ash ponds located near power stations. This has lain to waste thousands of hectares of land all over the world. Since leaching is often the cause of off-site contamination and pathway of introduction into the human environment, a study on the genotoxic effects of fly ash leachate is essential. Leachate prepared from the fly ash sample was analyzed for metal content, and tested for mutagenicity and genotoxicity. Analyses of metals show predominance of the metals-sodium, silicon, potassium, calcium, magnesium, iron, manganese, zinc, and sulphate. The Ames Salmonella mutagenicity assay, a short-term bacterial reverse mutation assay, was conducted on two-tester strains of Salmonella typhimurium strains TA97a and TA102. For genotoxicity, the alkaline version of comet assay on fly ash leachate was carried in vitro on human blood cells and in vivo on Nicotiana plants. The leachate was directly mutagenic and induced significant (Ppercentage (%), tail length (mum), and olive tail moment (arbitrary units). Our results indicate that leachate from fly ash dumpsites has the genotoxic potential and may lead to adverse effects on vegetation and on the health of exposed human populations.

Evaluation of Genotoxic Pressure along the Sava River.

Directory of Open Access Journals (Sweden)

Stoimir Kolarević

Full Text Available In this study we have performed a comprehensive genotoxicological survey along the 900 rkm of the Sava River. In total, 12 sites were chosen in compliance with the goals of GLOBAQUA project dealing with the effects of multiple stressors on biodiversity and functioning of aquatic ecosystems. The genotoxic potential was assessed using a complex battery of bioassays performed in prokaryotes and aquatic eukaryotes (freshwater fish. Battery comprised evaluation of mutagenicity by SOS/umuC test in Salmonella typhimurium TA1535/pSK1002. The level of DNA damage as a biomarker of exposure (comet assay and biomarker of effect (micronucleus assay and the level of oxidative stress as well (Fpg-modified comet assay was studied in blood cells of bleak and spirlin (Alburnus alburnus/Alburnoides bipunctatus respectively. Result indicated differential sensitivity of applied bioassays in detection of genotoxic pressure. The standard and Fpg-modified comet assay showed higher potential in differentiation of the sites based on genotoxic potential in comparison with micronucleus assay and SOS/umuC test. Our data represent snapshot of the current status of the river which indicates the presence of genotoxic potential along the river which can be traced to the deterioration of quality of the Sava River by communal and industrial wastewaters. The major highlight of the study is that we have provided complex set of data obtained from a single source (homogeneity of analyses for all samples.

Plant genotoxicity: a molecular cytogenetic approach in plant bioassays.

Science.gov (United States)

Maluszynska, Jolanta; Juchimiuk, Jolanta

2005-06-01

It is important for the prevention of DNA changes caused by environment to understand the biological consequences of DNA damages and their molecular modes of action that lead to repair or alterations of the genetic material. Numerous genotoxicity assay systems have been developed to identify DNA reactive compounds. The available data show that plant bioassays are important tests in the detection of genotoxic contamination in the environment and the establishment of controlling systems. Plant system can detect a wide range of genetic damage, including gene mutations and chromosome aberrations. Recently introduced molecular cytogenetic methods allow analysis of genotoxicity, both at the chromosomal and DNA level. FISH gives a new possibility of the detection and analysis of chromosomal rearrangements in a great detail. DNA fragmentation can be estimated using the TUNEL test and the single cell gel electrophoresis (Comet assay).

Evaluation of Cytotoxicity and Genotoxicity of Acacia aroma Leaf Extracts

Directory of Open Access Journals (Sweden)

C. M. Mattana

2014-01-01

Full Text Available Acacia aroma, native plant from San Luis, Argentina, is commonly used as antiseptic and for healing of wounds. The present study was conducted to investigate the in vitro cytotoxicity and genotoxicity of hot aqueous extract (HAE and ethanolic extract (EE of A. aroma. The cytotoxic activity was assayed by neutral red uptake assay on Vero cell. Cell treatment with a range from 100 to 5000 μg/mL of HAE and EE showed that 500 μg/mL and 100 μg/mL were the maximum noncytotoxic concentrations, respectively. The CC50 was 658 μg/mL for EE and 1020 μg/mL for HAE. The genotoxicity was tested by the single-cell gel electrophoresis comet assay. The results obtained in the evaluation of DNA cellular damage exposed to varied concentrations of the HAE showed no significant genotoxic effect at range of 1–20 mg/mL. The EE at 20 mg/mL showed moderate genotoxic effect related to the increase of the DNA percentage contained in tail of the comet; DNA was classified in category 2. At concentrations below 5 mg/mL, the results of cytotoxicity and genotoxicity of aqueous and ethanolic extracts of Acacia aroma guarantee the safety at cell and genomic level. However further studies are needed for longer periods including animal models to confirm the findings.

Genotoxicity of drinking water treated with different disinfectants and effects of disinfection conditions detected by umu-test.

Science.gov (United States)

Nie, Xuebiao; Liu, Wenjun; Zhang, Liping; Liu, Qing

2017-06-01

The genotoxicity of drinking water treated with 6 disinfection methods and the effects of disinfection conditions were investigated using the umu-test. The pretreatment procedure of samples for the umu-test was optimized for drinking water analysis. The results of the umu-test were in good correlation with those of the Ames-test. The genotoxicity and production of haloacetic acids (HAAs) were the highest for chlorinated samples. UV+chloramination is the safest disinfection method from the aspects of genotoxicity, HAA production and inactivation effects. For chloramination, the effects of the mass ratio of Cl 2 to N of chloramine on genotoxicity were also studied. The changes of genotoxicity were different from those of HAA production, which implied that HAA production cannot represent the genotoxic potential of water. The genotoxicity per chlorine decay of chlorination and chloramination had similar trends, indicating that the reaction of organic matters and chlorine made a great contribution to the genotoxicity. The results of this study are of engineering significance for optimizing the operation of waterworks. Copyright © 2016. Published by Elsevier B.V.

Somatic cell genotoxicity at the glycophorin A locus in humans

International Nuclear Information System (INIS)

Jensen, R.H.; Grant, S.G.; Langlois, R.G.; Bigbee, W.L.

1990-01-01

We have developed an assay for detecting variant erythrocytes that occur as a result of in vivo allele loss at the glycophorin A (GPA) locus on chromosome 4 in humans. This gene codes for an erythroid- specific cell surface glycoprotein, and with our assay we are able to detect rare variant erythrocytes that have lost expression of one of the two GPA alleles. Two distinctly different variant cell types are detected with this assay. One variant cell type (called N OE) is hemizygous. Our assay also detects homozygous variant erythrocytes that have lost expression of the GPA(M) allele and express the GPA(N) allele at twice the heterozygous level. The results of this assay are an enumeration of the frequency of N OE and NN variant cell types for each individual analyzed. These variant cell frequencies provide a measure of the amount of somatic cell genotoxicity that has occurred at the GPA locus. Such genotoxicity could be the result of (1) reactions of toxic chemicals to which the individual has been exposed, or (2) high energy radiation effects on erythroid precursor cells, or (3) errors in DNA replication or repair in these cells of the bone marrow. Thus, the GPA-based variant cell frequency can serve as a biodosimeter that indicates the amount of genotoxic exposure each individual has received. Because two very different kinds of variant cells are enumerated, different kinds of genotoxicity should be distinguishable. Results of the GPA somatic genotoxicity assay may also provide valuable information for cancer-risk estimation on each individual. 16 refs

Genistein genotoxicity: Critical considerations of in vitro exposure dose

International Nuclear Information System (INIS)

Klein, Catherine B.; King, Audrey A.

2007-01-01

The potential health benefits of soy-derived phytoestrogens include their reported utility as anticarcinogens, cardioprotectants and as hormone replacement alternatives in menopause. Although there is increasing popularity of dietary phytoestrogen supplementation and of vegetarian and vegan diets among adolescents and adults, concerns about potential detrimental or other genotoxic effects persist. While a variety of genotoxic effects of phytoestrogens have been reported in vitro, the concentrations at which such effects occurred were often much higher than the physiologically relevant doses achievable by dietary or pharmacologic intake of soy foods or supplements. This review focuses on in vitro studies of the most abundant soy phytoestrogen, genistein, critically examining dose as a crucial determinant of cellular effects. In consideration of levels of dietary genistein uptake and bioavailability we have defined in vitro concentrations of genistein > 5 μM as non-physiological, and thus 'high' doses, in contrast to much of the previous literature. In doing so, many of the often-cited genotoxic effects of genistein, including apoptosis, cell growth inhibition, topoisomerase inhibition and others become less obvious. Recent cellular, epigenetic and microarray studies are beginning to decipher genistein effects that occur at dietarily relevant low concentrations. In toxicology, the well accepted principle of 'the dose defines the poison' applies to many toxicants and can be invoked, as herein, to distinguish genotoxic versus potentially beneficial in vitro effects of natural dietary products such as genistein

Genotoxicity of diuron and glyphosate in oyster spermatozoa and embryos.

Science.gov (United States)

Akcha, F; Spagnol, C; Rouxel, J

2012-01-15

We investigated the effects of genotoxicant exposure in gametes and embryos to find a possible link between genotoxicity and reproduction/developmental impairment, and explore the impact of chemical genotoxicity on population dynamics. Our study focused on the genotoxic effects of two herbicides on oyster gametes and embryos: glyphosate (both as an active substance and in the Roundup formulation) and diuron. France is Europe's leading consumer of agrochemical substances and as such, contamination of France's coastal waters by pesticides is a major concern. Glyphosate and diuron are among the most frequently detected herbicides in oyster production areas; as oyster is a specie with external reproduction, its gametes and embryos are in direct contact with the surrounding waters and are hence particularly exposed to these potentially dangerous substances. In the course of this study, differences in genotoxic and embryotoxic responses were observed in the various experiments, possibly due to differences in pollutant sensitivity between the tested genitor lots. Glyphosate and Roundup had no effect on oyster development at the concentrations tested, whereas diuron significantly affected embryo-larval development from the lowest tested concentration of 0.05 μg L⁻¹, i.e. an environmentally realistic concentration. Diuron may therefore have a significant impact on oyster recruitment rates in the natural environment. Our spermiotoxicity study revealed none of the tested herbicides to be cytotoxic for oyster spermatozoa. However, the alkaline comet assay showed diuron to have a significant genotoxic effect on oyster spermatozoa at concentrations of 0.05 μg L⁻¹ upwards. Conversely, no effects due to diuron exposure were observed on sperm mitochondrial function or acrosomal membrane integrity. Although our initial results showed no negative effect on sperm function, the possible impact on fertilization rate and the consequences of the transmission of damaged DNA for

Cytotoxicity and genotoxicity of biogenic silver nanoparticles

International Nuclear Information System (INIS)

Lima, R; Feitosa, L O; Ballottin, D; Tasic, L; Durán, N; Marcato, P D

2013-01-01

Biogenic silver nanoparticles with 40.3 ± 3.5 nm size and negative surface charge (− 40 mV) were prepared with Fusarium oxysporum. The cytotoxicity of 3T3 cell and human lymphocyte were studied by a TaliTM image-based cytometer and the genotoxicity through Allium cepa and comet assay. The results of BioAg-w (washed) and BioAg-nw (unwashed) biogenic silver nanoparticles showed cytotoxicity exceeding 50 μg/mL with no significant differences of response in 5 and 10 μg/mL regarding viability. Results of genotoxicity at concentrations 5.0 and 10.0 ug/mL show some response, but at concentrations 0.5 and 1.0 μg/mL the washed and unwashed silver nanoparticles did not present any effect. This in an important result since in tests with different bacteria species and strains, including resistant, MIC (minimal inhibitory concentration) had good answers at concentrations less than 1.9 μg/mL. This work concludes that biogenic silver nanoparticles may be a promising option for antimicrobial use in the range where no cyto or genotoxic effect were observed. Furthermore, human cells were found to have a greater resistance to the toxic effects of silver nanoparticles in comparison with other cells.

Genotoxic pressure of vineyard pesticides in fish: field and mesocosm surveys.

Science.gov (United States)

Bony, S; Gillet, C; Bouchez, A; Margoum, C; Devaux, A

2008-09-17

The present study deals with the genotoxicity assessment of vineyard pesticides in fish exposed in the field or in mesocosm conditions. Primary DNA damage was quantified as strand breaks using the single cell gel electrophoresis assay (Comet assay) applied to fish erythrocytes. In a first experiment, a significant genotoxic effect was observed following an upstream-downstream gradient in early life stages of brown trout (Salmo trutta fario) exposed in the Morcille River contaminated by a mixture of vineyard pesticides during three consecutive years. The pronounced response in terms of DNA damage reported in the present study could argue for a high sensitivity of fish early life stage and/or a high level of exposure to genotoxic compounds in the Morcille River. This stresses the interest in using trout larvae incubated in sediment bed to assess genotoxic compounds in the field. In a second experiment, adult European topminnow (Phoxinus phoxinus) were exposed in water running through artificial channels to a mixture of diuron and azoxystrobin, two of the main pesticides detected in the Morcille watershed. As compared with the unexposed channel, a 3-5-fold increase in the DNA damage was observed in fish exposed to chronic environmental pesticide concentrations (1-2 microg L(-1) for diuron and 0.5-1 microg L(-1) for axoxystrobin). A single 6h pulse of pesticide (14 microg L(-1) of diuron and 7 microg L(-1) of azoxystrobin) was applied to simulate transiently elevated chemical concentrations in the river following storm conditions. It did not increase genotoxicity. After a 1-month recovery period, DNA damage in exposed fish erythrocytes recovered to unexposed level, suggesting possible involvement of both repair mechanisms and cellular turnover in this transient response. This work highlights that vineyard treatment by pesticides and in particular diuron and azoxystrobin can represent a genotoxic threat to fish from contaminated watershed rivers.

In vitro and in vivo genotoxic evaluation of Bothrops moojeni snake venom.

Science.gov (United States)

Novak Zobiole, Nathalia; Caon, Thiago; Wildgrube Bertol, Jéssica; Pereira, Cintia Alves de Souza; Okubo, Brunna Mary; Moreno, Susana Elisa; Cardozo, Francielle Tramontini Gomes de Sousa

2015-06-01

Bothrops moojeni Hoge (Viperidae) venom is a complex mixture of compounds with therapeutic potential that has been included in the research and development of new drugs. Along with the biological activity, the pharmaceutical applicability of this venom depends on its toxicological profile. This study evaluates the cytotoxicity and genotoxicity of the Bothrops moojeni venom (BMV). The in vitro cytotoxicity and genotoxicity of a pooled sample of BMV was assessed by the MTT and Comet assay, respectively. Genotoxicity was also evaluated in vivo through the micronucleus assay. BMV displayed a 50% cytotoxic concentration (CC50) on Vero cells of 4.09 µg/mL. Vero cells treated with 4 µg/mL for 90 min and 6 h presented significant (p < 0.05, ANOVA/Newman-Keuls test) higher DNA damage than the negative control in the Comet assay. The lower DNA damage found after 6 h compared with the 90 min treatment suggests a DNA repair effect. Mice intraperitoneally treated with BMV at 10, 30, or 80 µg/animal presented significant genotoxicity (p < 0.05, ANOVA/Newman-Keuls test) in relation to the negative control after 24 h of treatment. Contrary to the in vitro results, no DNA repair seemed to occur in vivo up to 96 h post-venom inoculation at a dose of 30 µg/animal. The results show that BMV presents cyto- and genotoxicity depending on the concentration/dose used. These findings emphasize the importance of toxicological studies, including assessment of genotoxicity, in the biological activity research of BMV and/or in the development of BMV-derived products.

Genotoxicity of Superparamagnetic Iron Oxide Nanoparticles in Granulosa Cells

Directory of Open Access Journals (Sweden)

Marina Pöttler

2015-11-01

Full Text Available Nanoparticles that are aimed at targeting cancer cells, but sparing healthy tissue provide an attractive platform of implementation for hyperthermia or as carriers of chemotherapeutics. According to the literature, diverse effects of nanoparticles relating to mammalian reproductive tissue are described. To address the impact of nanoparticles on cyto- and genotoxicity concerning the reproductive system, we examined the effect of superparamagnetic iron oxide nanoparticles (SPIONs on granulosa cells, which are very important for ovarian function and female fertility. Human granulosa cells (HLG-5 were treated with SPIONs, either coated with lauric acid (SEONLA only, or additionally with a protein corona of bovine serum albumin (BSA; SEONLA-BSA, or with dextran (SEONDEX. Both micronuclei testing and the detection of γH2A.X revealed no genotoxic effects of SEONLA-BSA, SEONDEX or SEONLA. Thus, it was demonstrated that different coatings of SPIONs improve biocompatibility, especially in terms of genotoxicity towards cells of the reproductive system.

Exogenous vs. Endogenous Separation

OpenAIRE

Ramey, Garey

2008-01-01

This paper assesses how various approaches to modelling the separation margin a¤ect the ability of the Mortensen-Pissarides job matching model to explain key facts about the aggregate labor market. Allowing for realistic time variation in the separation rate, whether exogenous or endogenous, greatly in- creases the unemployment variability generated by the model. Speci…cations with exogenous separation rates, whether constant or time-varying, fail to pro- duce realistic volatility and prod...

Considerations on photochemical genotoxicity. II: Report of the 2009 International Workshop on Genotoxicity Testing Working Group

NARCIS (Netherlands)

Lynch, A.M.; Guzzie, P.J.; Bauer, D.; Gocke, E.; Itoh, S.; Jacobs, A.; Krul, C.A.M.; Schepky, A.; Tanaka, N.; Kasper, P.

2011-01-01

A workshop to reappraise the previous IWGT recommendations for photogenotoxicity testing [E. Gocke, L. Muller, P.J. Guzzie, S. Brendler-Schwaab, S. Bulera, C.F. Chignell, L.M. Henderson, A. Jacobs, H. Murli, R.D. Snyder, N. Tanaka, Considerations on photochemical genotoxicity: report of the

AFFINITY BIOSENSOR BASED ON SCREEN-PRINTED ELECTRODE MODIFIED WITH DNA FOR GENOTOXIC COMPOUNDS DETECTION

Directory of Open Access Journals (Sweden)

Bambang Kuswandi

2010-06-01

Full Text Available An electrochemical method for the detection of the genotoxic compounds using a DNA-modified electrode was developed. This electrode was successfully used for the electrochemical detection of genotoxic compounds in water samples. The electrochemical results clearly demonstrated that, the development is related to the molecular interaction between the surface-linked DNA obtained from calf thymus and the target compounds, such as pollutants, in order to develop a simple device for rapid screening of genotoxic compounds in environmental samples. The detection of such compounds was measured by their effect on the oxidation signal of the guanine peak of the DNA immobilised on the surface of carbon based Screen-Printed Electrode (SPE in disposable mode, and monitored by square-wave voltametric analysis. The DNA biosensor is able to detect known intercalating and groove-binding genotoxic compounds such as Dioxin, Bisphenol A, PCBs, and Phtalates. Application to real water samples is discussed and reported.   Keywords: electrochemical, screen-printed electrode, DNA biosensor, genotoxic compounds

Genotoxic Maillard byproducts in current phytopharmaceutical preparations of Echinodorus grandiflorus

Directory of Open Access Journals (Sweden)

ELISANGELA C. LIMA-DELLAMORA

2014-09-01

Full Text Available Extracts of Echinodorus grandiflorus obtained from dried leaves by three different techniques were evaluated by bacterial lysogenic induction assay (Inductest in relation to their genotoxic properties. Before being added to test cultures, extracts were sterilized either by steam sterilization or ultraviolet light. Only the extracts prepared by infusion and steam sterilized have shown genotoxic activity. The phytochemical analysis revealed the presence of the flavonoids isovitexin, isoorientin, swertisin and swertiajaponin, isolated from a genotoxic fraction. They were assayed separately and tested negative in the Inductest protocol. The development of browning color and sweet smell in extracts submitted to heat, prompted further chemical analysis in search for Maillard's reaction precursors. Several aminoacids and reducing sugars were cast in the extract. The presence of characteristic Maillard's melanoidins products was determined by spectrophotometry in the visible region and the inhibition of this reaction was observed when its characteristic inhibitor, sodium bisulfite, was added prior to heating. Remarkably, this is the first paper reporting on the appearance of such compounds in a phytomedicine preparation under a current phytopharmaceutical procedure. The genotoxic activity of such heat-prepared infusions imply in some risk of developing degenerative diseases for patients in long-term, uncontrolled use of such phytomedicines.

Correlation between serum anyloid a low density lipoprotein and genotoxicity in smokers

International Nuclear Information System (INIS)

Jamil, A.; Rashid, A.; Majeed, A.; Naveed, A.K.

2018-01-01

Objective:To investigate the relation between serum amyloid A-low density lipoprotein (SAA-LDL) and genotoxicity in smokers. Study Design:An experimental study. Place and Duration of Study:Army Medical College, Rawalpindi and National Institute of Health (NIH), Islamabad, from June 2014 to February 2015. Methodology:Seventy healthy Sprague Dawley rats were purchased from NIH and exposed to cigarette smoke in smoke chamber for three months. Blood samples were drawn from each rat at the end of the study period. SAA-LDL was determined by enzyme-linked immunosorbent assay (ELISA). Genotoxicity was assessed by cytokinesis block micronucleus (CBMN) assay. Pearson correlation was used to find correlation between SAA-LDL and genotoxicity. Results:Strong positive correlation was found between SAA-LDL and micronuclei frequency in smoke-exposed rats (r=0.799, N=70, p <0.01). Conclusion:Statistically significant strong positive correlation between SAA-LDL and genotoxicity in smoke-exposed rats shows that changes in one is associated with changes in other and vice versa. (author)

Evaluation of perfluorooctanoate for potential genotoxicity

Directory of Open Access Journals (Sweden)

John L. Butenhoff

2014-01-01

Full Text Available Perfluorooctanoate (PFOA is a fully fluorinated eight-carbon fatty acid analog with exceptional stability toward degradation that has been used as an industrial surfactant and has been detected in environmental and biological matrices. Exposures to PFOA in the workplace and in the environment have continuously stimulated investigations into its potential human health hazards. In this article, the results of fifteen unpublished genotoxicity assays conducted with perfluorooctanoate (as either the linear or linear/branched ammonium salt (APFO or the linear/branched sodium salt are reported and include: seven mutation assays (three in vitro reverse mutation assays with histidine auxotrophic strains of Salmonella typhimurium, two in vitro reverse mutation assays with the tryptophan auxotrophic Escherichia coli WP2uvr strain, one in vitro mitotic recombination (gene conversion assay with Saccharomyces cerevisiae D4, and an in vitro Chinese hamster ovary (CHO HGPRT forward mutation assay; seven studies to assess potential for chromosomal damage (three in vitro CHO chromosomal aberration studies, an in vitro human whole blood lymphocyte chromosomal aberration study, and three in vivo mouse micronucleus assays; and an in vitro C3H 10T1/2 cell transformation assay. Although PFOA has not been demonstrated to be metabolized, all in vitro assays were conducted both in the presence and in the absence of a mammalian hepatic microsomal activation system. These assays were originally described in twelve contract laboratory reports which have been available via the United States Environmental Protection Agency public docket (Administrative Record 226 for over a decade; however, the details of these assays have not been published previously in the open scientific literature. With the exception of limited positive findings at high and cytotoxic concentrations in some assay trials which reflected the likely consequence of cytotoxic disruption of normal cellular

Evaluation of genotoxicity of nitrile fragrance ingredients using in vitro and in vivo assays.

Science.gov (United States)

Bhatia, S P; Politano, V T; Api, A M

2013-09-01

Genotoxicity studies were conducted on a group of 8 fragrance ingredients that belong to the nitrile family. These nitriles are widely used in consumer products however there is very limited data in the literature regarding the genotoxicity of these nitriles. The 8 nitriles were assessed for genotoxicity using an Ames test, in vitro chromosome aberration test or in vitro micronucleus test. The positive results observed in the in vitro tests were further investigated using an in vivo micronucleus test. The results from these different tests were compared and these 8 nitriles are not considered to be genotoxic. Dodecanitrile and 2,2,3-trimethylcyclopent-3-enylacetonitrile were negative in the in vitro chromosome aberration test and in vitro micronucleus test, respectively. While citronellyl nitrile, 3-methyl-5-phenylpentanenitrile, cinnamyl nitrile, and 3-methyl-5-phenylpent-2-enenitrile revealed positive results in the in vitro tests, but confirmatory in vivo tests determined these nitriles to be negative in the in vivo micronucleus assay. The remaining two nitriles (benzonitrile and α-cyclohexylidene benzeneacetonitrile) were negative in the in vivo micronucleus test. This study aims to evaluate the genotoxicity potential of these nitriles as well as enrich the literature with genotoxicity data on fragrance ingredients. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cytotoxicity and genotoxicity of clothianidin in human lymphocytes with or without metabolic activation system.

Science.gov (United States)

Atlı Şekeroğlu, Zülal; Şekeroğlu, Vedat; Uçgun, Ebru; Kontaş Yedier, Seval; Aydın, Birsen

2018-02-26

Clothianidin (CHN) is a broad-spectrum neonicotinoid insecticide. Limited studies have been carried out on the cytotoxic and genotoxic effects of both CHN using different genotoxicity tests in human cells with or without human metabolic activation system (S9 mix). Therefore, the aim of this study is to investigate the cytotoxic and genotoxic effects of CHN and its metabolites on human lymphocyte cultures with or without S9 mix using chromosomal aberration (CA) and micronucleus (MN) tests. The cultures were treated with 25, 50, and 100 µg/ml of CHN in the presence (3 h treatment) and absence (48 h treatment) of S9 mix. Dimethyl sulfoxide (DMSO) was used as a solvent control. CHN showed cytotoxic and genotoxic effects due to significant decreases in mitotic index (MI) and nuclear division index (NDI), and significant increases in the CAs, aberrant cells, and MN formation in the absence of S9 mix when compared with solvent control. However, CHN did not significantly induce cytotoxicity and genotoxicity in the presence of S9 mix. Our results indicated that CHN has cytotoxic, cytostatic, and genotoxic potential on human peripheral blood lymphocyte cultures, but not its metabolites under the experimental conditions.

Molecular and cytogenetic assessment of Dipterygium glaucum genotoxicity

Directory of Open Access Journals (Sweden)

NADA H. ALTWATY

2016-01-01

Full Text Available ABSTRACT The aim of the present study is to assess the genotoxicity of Dipterygium glaucum grows widely in Saudi Arabia desert to produce safety herbal products. This work is considered the first and pioneer report so far due to the lack and poor evaluated reports of the plant species for their mutagensity, genotoxicity and cytogenetics effects. Cytogenetic effects of D. glaucum on mitotic in roots of Vicia faba showed reduction in mitotic activity using three extracts; water, ethanol and ethyl acetate. Chromosomal abnormalities were recorded that included stickiness of chromosomes, chromatin bridge, fragments, lagging chromosome and micronuclei. Protein bands and RAPD analyses of V. faba treated with three D. glaucum extracts revealed some newly induced proteins and DNA fragments and other disappeared. Chemical constitution of the plant species should be identified with their biological activities against human and animal cells like HeLa cancer cell line. We are recommending using additional genotoxicity tests and other toxicity tests on animal culture with different concentrations and also utilizing several drought and heat tolerant genes of the plant species in gene cloning to develop and improve other economical crop plants instead of using the species as oral herbal remedy

Visible propagation from invisible exogenous cueing.

Science.gov (United States)

Lin, Zhicheng; Murray, Scott O

2013-09-20

Perception and performance is affected not just by what we see but also by what we do not see-inputs that escape our awareness. While conscious processing and unconscious processing have been assumed to be separate and independent, here we report the propagation of unconscious exogenous cueing as determined by conscious motion perception. In a paradigm combining masked exogenous cueing and apparent motion, we show that, when an onset cue was rendered invisible, the unconscious exogenous cueing effect traveled, manifesting at uncued locations (4° apart) in accordance with conscious perception of visual motion; the effect diminished when the cue-to-target distance was 8° apart. In contrast, conscious exogenous cueing manifested in both distances. Further evidence reveals that the unconscious and conscious nonretinotopic effects could not be explained by an attentional gradient, nor by bottom-up, energy-based motion mechanisms, but rather they were subserved by top-down, tracking-based motion mechanisms. We thus term these effects mobile cueing. Taken together, unconscious mobile cueing effects (a) demonstrate a previously unknown degree of flexibility of unconscious exogenous attention; (b) embody a simultaneous dissociation and association of attention and consciousness, in which exogenous attention can occur without cue awareness ("dissociation"), yet at the same time its effect is contingent on conscious motion tracking ("association"); and (c) underscore the interaction of conscious and unconscious processing, providing evidence for an unconscious effect that is not automatic but controlled.

Genotoxicity of antiobesity drug orlistat and effect of caffeine intervention: an in vitro study.

Science.gov (United States)

Chakrabarti, Manoswini; Ghosh, Ilika; Jana, Aditi; Ghosh, Manosij; Mukherjee, Anita

2017-07-01

Obesity is a major global health problem associated with various adverse effects. Pharmacological interventions are often necessary for the management of obesity. Orlistat is an FDA-approved antiobesity drug which is a potent inhibitor of intestinal lipases. In the current study, orlistat was evaluated for its genotoxic potential in human lymphocyte cells in vitro and was compared with that of another antiobesity drug sibutramine, presently withdrawn from market due its undesirable health effects. Caffeine intake may be an additional burden in people using anorectic drugs, therefore, further work is needed to be carried out to evaluate the possible effects of caffeine on orlistat-induced DNA damage. Human lymphocytes were exposed to orlistat (250, 500 and 1000 μg/ml), sibutramine (250, 500 and 1000 μg/ml) and caffeine (25, 50, 75, 100, 125 and 150 μg/ml) to assess their genotoxicity by comet assay in vitro. In addition, lymphocytes were co-incubated with caffeine (50, 75 and 100 μg/ml) and a single concentration of orlistat (250 μg/ml). Orlistat and sibutramine were genotoxic at all concentrations tested, sibutramine being more genotoxic. Caffeine was found to be genotoxic at concentrations 125 μg/ml and above. Co-treatment of orlistat with non-genotoxic concentrations (50, 75 and 100 μg/ml) of caffeine lead to a decrease in DNA damage. Orlistat can induce DNA damage in human lymphocytes in vitro and caffeine was found to reduce orlistat-induced genotoxicity.

The cytotoxicity and genotoxicity of soluble and particulate cobalt in human lung fibroblast cells

Energy Technology Data Exchange (ETDEWEB)

Smith, Leah J.; Holmes, Amie L. [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Maine Center for Environmental Toxicology and Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Kandpal, Sanjeev Kumar; Mason, Michael D. [Department of Chemical and Biological Engineering, University of Maine, Orono, ME (United States); Zheng, Tongzhang [Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT (United States); Wise, John Pierce, E-mail: John.Wise@usm.maine.edu [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Maine Center for Environmental Toxicology and Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States)

2014-08-01

Cobalt exposure is increasing as cobalt demand rises worldwide due to its use in enhancing rechargeable battery efficiency, super-alloys, and magnetic products. Cobalt is considered a possible human carcinogen with the lung being a primary target. However, few studies have considered cobalt-induced toxicity in human lung cells. Therefore, in this study, we sought to determine the cytotoxicity and genotoxicity of particulate and soluble cobalt in human lung cells. Cobalt oxide and cobalt chloride were used as representative particulate and soluble cobalt compounds, respectively. Exposure to both particulate and soluble cobalt induced a concentration-dependent increase in cytotoxicity, genotoxicity, and intracellular cobalt ion levels. Based on intracellular cobalt ion levels, we found that soluble cobalt was more cytotoxic than particulate cobalt while particulate and soluble cobalt induced similar levels of genotoxicity. However, soluble cobalt induced cell cycle arrest indicated by the lack of metaphases at much lower intracellular cobalt concentrations compared to cobalt oxide. Accordingly, we investigated the role of particle internalization in cobalt oxide-induced toxicity and found that particle-cell contact was necessary to induce cytotoxicity and genotoxicity after cobalt exposure. These data indicate that cobalt compounds are cytotoxic and genotoxic to human lung fibroblasts, and solubility plays a key role in cobalt-induced lung toxicity. - Highlights: • Particulate and soluble cobalt are cytotoxic and genotoxic to human lung cells. • Soluble cobalt induces more cytotoxicity compared to particulate cobalt. • Soluble and particulate cobalt induce similar levels of genotoxicity. • Particle-cell contact is required for particulate cobalt-induced toxicity.

Calculating Adversarial Risk from Attack Trees: Control Strength and Probabilistic Attackers

NARCIS (Netherlands)

Pieters, Wolter; Davarynejad, Mohsen

2015-01-01

Attack trees are a well-known formalism for quantitative analysis of cyber attacks consisting of multiple steps and alternative paths. It is possible to derive properties of the overall attacks from properties of individual steps, such as cost for the attacker and probability of success. However, in

Comparative Physicochemical and Genotoxicity Assessments of ...

African Journals Online (AJOL)

ADOWIE PERE

ABSTRACT: The textile industry has become indispensable in view of its basic and social importance to human life, but its environmental impact has continued to be a subject of concern. ... the economy of many countries. ... Textile and clothing production process ..... Genotoxicity screening of industrial effluents using.

Genotoxicity of clays with potential use in biopolymers for food packaging

DEFF Research Database (Denmark)

Sharma, Anoop Kumar; Mortensen, Alicja; Hadrup, Niels

Genotoxicity of clays with potential use in biopolymers for food packaging Plastics produced from biopolymers are of commercial interest as they are manufactured from renewable resources such as agricultural crop wastes and have the potential to meet environmental and health requirements. Biopoly......Genotoxicity of clays with potential use in biopolymers for food packaging Plastics produced from biopolymers are of commercial interest as they are manufactured from renewable resources such as agricultural crop wastes and have the potential to meet environmental and health requirements...... in crude suspensions (suspended in cell culture medium) and crude suspensions filtrated through a 0.2 µm pore size filter in order to investigate the potential effect of “nanoparticles” only. The two clays showed noticeable differences in genotoxicity; both crude and filtered suspensions of Cloisite...

Bluetooth security attacks comparative analysis, attacks, and countermeasures

CERN Document Server

Haataja, Keijo; Pasanen, Sanna; Toivanen, Pekka

2013-01-01

This overview of Bluetooth security examines network vulnerabilities and offers a comparative analysis of recent security attacks. It also examines related countermeasures and proposes a novel attack that works against all existing Bluetooth versions.

Genotoxic effects of boric acid and borax in zebrafish, Danio rerio using alkaline comet assay.

Science.gov (United States)

Gülsoy, Nagihan; Yavas, Cüneyd; Mutlu, Özal

2015-01-01

The present study is conducted to determine the potential mechanisms of Boron compounds, boric acid (BA) and borax (BX), on genotoxicity of zebrafish Danio rerio for 24, 48, 72 and 96-hours acute exposure (level:1, 4, 16, 64 mg/l BA and BX) in semi-static bioassay experiment. For that purpose, peripheral erythrocytes were drawn from caudal vein and Comet assay was applied to assess genotoxicity. Acute (96 hours) exposure and high concentrations of boric acid and borax increases % tail DNA and Olive tail moment. Genotoxicity was found for BA as concentration-dependent and BX as concentration and time dependent manner. In general, significant effects (P borax-induced genotoxicity in fish.

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers

OpenAIRE

Amrin Shaikh; Darshana Barot; Divya Chandel

2018-01-01

Background: Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals. Objective: To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers. Methods: The study groups included 70 petrol pump workers (exposed group) and 70 healthy age-matched individuals with no known exposure (comparison group). Buccal micronucleus cytome assay (BMCyt) was performed to check the genotoxicity caused due to inhalation ...

Evaluation of the tickcide, genotoxic, and mutagenic effects of the Ruta graveolens L. (Rutaceae

Directory of Open Access Journals (Sweden)

Alessandra Vargas de Carvalho

2015-10-01

Full Text Available Current analysis investigated the tickcide effects of the aqueous extract and chloroform fractions of Ruta graveolens L. (rue on engorged females of Rhipicephalus microplus, as well as their genotoxic and mutagenic effects on human leukocytes. The best tickcide activity (non-dependent dose and genotoxic / mutagenic effects (dependent-dose were observed on exposure to chloroform fractions. Results suggest that extract fractions of R. graveolens L are efficient against R. microplus, although the fraction and the tested concentrations show genotoxic and mutagenic potential for human leukocytes.

Assessing the genotoxicity of urban air pollutants using two in situ plant bioassays

Energy Technology Data Exchange (ETDEWEB)

Villarini, M.; Fatigoni, C.; Dominici, L.; Maestri, S. [Department of Medical-Surgical Specialties and Public Health, University of Perugia, I-06126 (Italy); Ederli, L.; Pasqualini, S. [Department of Applied Biology, University of Perugia, I-06121 (Italy); Monarca, S. [Department of Medical-Surgical Specialties and Public Health, University of Perugia, I-06126 (Italy); Moretti, M., E-mail: massimo.moretti@unipg.i [Department of Medical-Surgical Specialties and Public Health, University of Perugia, I-06126 (Italy)

2009-12-15

Genotoxicity of urban air has been analysed almost exclusively in airborne particulates. We monitored the genotoxic effects of airborne pollutants in the urban air of Perugia (Central Italy). Two plant bioindicators with different genetic endpoints were used: micronuclei in meiotic pollen mother cells using Tradescantia-micronucleus bioassay (Trad-MCN) and DNA damage in nuclei of Nicotiana tabacum leaves using comet assay (Nicotiana-comet). Buds of Tradescantia clone no. 4430 and young N. tabacum cv. Xanthi plants were exposed for 24 h at three sites with different pollution levels. One control site (indoor control) was also used. The two bioassays showed different sensitivities toward urban pollutants: Trad-MCN assay was the most sensitive, but DNA damage in N. tabacum showed a better correlation with the pollutant concentrations. In situ biomonitoring of airborne genotoxins using higher plants combined with chemical analysis is thus recommended for characterizing genotoxicity of urban air. - Plant bioassays used to explore in situ the correlation between air pollution and genotoxicity.

Assessing the genotoxicity of urban air pollutants using two in situ plant bioassays

International Nuclear Information System (INIS)

Villarini, M.; Fatigoni, C.; Dominici, L.; Maestri, S.; Ederli, L.; Pasqualini, S.; Monarca, S.; Moretti, M.

2009-01-01

Genotoxicity of urban air has been analysed almost exclusively in airborne particulates. We monitored the genotoxic effects of airborne pollutants in the urban air of Perugia (Central Italy). Two plant bioindicators with different genetic endpoints were used: micronuclei in meiotic pollen mother cells using Tradescantia-micronucleus bioassay (Trad-MCN) and DNA damage in nuclei of Nicotiana tabacum leaves using comet assay (Nicotiana-comet). Buds of Tradescantia clone no. 4430 and young N. tabacum cv. Xanthi plants were exposed for 24 h at three sites with different pollution levels. One control site (indoor control) was also used. The two bioassays showed different sensitivities toward urban pollutants: Trad-MCN assay was the most sensitive, but DNA damage in N. tabacum showed a better correlation with the pollutant concentrations. In situ biomonitoring of airborne genotoxins using higher plants combined with chemical analysis is thus recommended for characterizing genotoxicity of urban air. - Plant bioassays used to explore in situ the correlation between air pollution and genotoxicity.

Genotoxicity Screening of Industrial Effluents using Onion bulbs ...

African Journals Online (AJOL)

Michael Horsfall

ABSTRACT: The potential cytotoxicity and genotoxicity of three industrial wastewaters (brewery .... National recommended water quality criteria – correction; cWorld Health Organisation (1996). ..... Industrial Pollution Policy Management Study.

Toward a Genotoxic Protection Factor

International Nuclear Information System (INIS)

Cesarini, J.P.; Demanneville, S.

2000-01-01

P53, a molecule normally expressed before mitosis, is considered as the 'guardian of the genome'. In the skin its level is normally very low (<3% of cells), detected by immunohistochemical methods. At least 50% of the keratinocytes express p53 protein, 24 h following a significant UV irradiation (2 SED). It is expected using sunscreens to reduce the expression of p53 in parallel with their ability to reduce the actinic erythema, the endpoint adopted to evaluate the Sun Protection Factor (SPF) of sunscreens. P53 detection on biopsies performed on the buttocks of human volunteers was used to evaluate the genotoxic protecting factor (GPF) of several sunscreens with either high UVB filtration or high UVA filtration, characterised by various SPF (COLIPA) from 10 to 40. The p53 count in parallel with sunburn cell count were the parameters studied. In general, the GPF of the sunscreens was found below the proprietary SPF. If a genotoxic effect is shown in an increased p53 expression, this effect is still observed at a dose lower than the dose inducing the faintest actinic erythema. (author)

Toward a Genotoxic Protection Factor

Energy Technology Data Exchange (ETDEWEB)

Cesarini, J.P.; Demanneville, S

2000-07-01

P53, a molecule normally expressed before mitosis, is considered as the 'guardian of the genome'. In the skin its level is normally very low (<3% of cells), detected by immunohistochemical methods. At least 50% of the keratinocytes express p53 protein, 24 h following a significant UV irradiation (2 SED). It is expected using sunscreens to reduce the expression of p53 in parallel with their ability to reduce the actinic erythema, the endpoint adopted to evaluate the Sun Protection Factor (SPF) of sunscreens. P53 detection on biopsies performed on the buttocks of human volunteers was used to evaluate the genotoxic protecting factor (GPF) of several sunscreens with either high UVB filtration or high UVA filtration, characterised by various SPF (COLIPA) from 10 to 40. The p53 count in parallel with sunburn cell count were the parameters studied. In general, the GPF of the sunscreens was found below the proprietary SPF. If a genotoxic effect is shown in an increased p53 expression, this effect is still observed at a dose lower than the dose inducing the faintest actinic erythema. (author)

Genotoxicity tests on D-tagatose.

Science.gov (United States)

Kruger, C L; Whittaker, M H; Frankos, V H

1999-04-01

D-tagatose is a low-calorie sweetener that tastes like sucrose. Its genotoxic potential was examined in five standard assays: the Ames Salmonella typhimurium reverse mutation assay, the Escherichia coli/mammalian microsome assay, a chromosomal aberration assay in Chinese hamster ovary cells, a mouse lymphoma forward mutation assay, and an in vivo mouse micronucleus assay. D-tagatose was not found to increase the number of revertants per plate relative to vehicle controls in either the S. typhimurium tester strains or the WP2uvrA- tester strain with or without metabolic activation at doses up to 5000 microg/plate. No significant increase in Chinese hamster ovary cells with chromosomal aberrations was observed at concentrations up to 5000 microg/ml with or without metabolic activation. D-tagatose was not found to increase the mutant frequency in mouse lymphoma L5178Y cells with or without metabolic activation up to concentrations of 5000 microg/ml. D-tagatose caused no significant increase in micronuclei in bone marrow polychromatic erythrocytes at doses up to 5000 mg/kg. D-tagatose was not found to be genotoxic under the conditions of any of the assays described above. Copyright 1999 Academic Press.

In vivo genotoxicity of nitramines, transformation products of amine-based carbon capture technology

Directory of Open Access Journals (Sweden)

Claire Coutris

2015-05-01

Full Text Available In times where we need to reduce our CO2 emissions to the atmosphere, it is important to get a clearer picture of the environmental impacts associated with potential mitigation technologies. Chemical absorption with amines is emerging as the most advanced mitigation technology for post-combustion capture of CO2 from fossil fuel power stations. Although the amine solvent used in this technology is recycled during the capture process, degradation products are formed and released into the environment. Among these degradation products, the aliphatic nitramine compounds dimethylnitramine and ethanolnitramine have been identified, whose environmental impact was unknown. In addition to conducting survival, growth and reproduction tests in a range of marine species, we looked into the in vivo genotoxic potential of these two compounds to experimentally exposed fish (Coutris et al. 2015. DNA damage was analyzed in blood samples collected from the caudal vein of juvenile turbot Scophthalmus maximus after 28 day exposure to nitramines, using the 12 mini-gels version of the comet assay, with and without digestion with formamidopyrimidine DNA glycosylase. Although whole organism bioassays indicated that nitramine toxicity through necrosis was low, the genotoxicity assessment revealed contrasting results, with ethanolnitramine found to be more genotoxic than dimethylnitramine by three orders of magnitude. At the lowest ethanolnitramine concentration (1 mg/L, 84 % DNA damage was observed, whereas 100 mg/L dimethylnitramine was required to cause 37 % DNA damage. The mechanisms of genotoxicity were also shown to differ between the two compounds, with oxidation of the DNA bases responsible for over 90 % of the genotoxicity of dimethylnitramine, whereas DNA strand breaks and alkali-labile sites were responsible for over 90 % of the genotoxicity of ethanolnitramine. Fish exposed to > 3 mg/L ethanolnitramine had virtually no DNA left in their red blood cells. The

In Vitro and In Vivo Genotoxicity Assessment of Aristolochia manshuriensis Kom.

Directory of Open Access Journals (Sweden)

Youn-Hwan Hwang

2012-01-01

Full Text Available Arisolochiae species plants containing aristolochic acids I and II (AA I and AA II are well known to cause aristolochic acid nephropathy (AAN. Recently, there are various approaches to use AAs-containing herbs after the removal of their toxic factors. However, there is little information about genotoxicity of Arisolochiae manshuriensis Kom. (AMK per se. To obtain safety information for AMK, its genotoxicity was evaluated in accordance with OECD guideline. To evaluate genotoxicity of AMK, we tested bacterial reverse mutation assay, chromosomal aberration test, and micronucleus test. Here, we also determined the amounts of AA I and II in AMK (2.85 ± 0.08 and 0.50 ± 0.02 mg/g extract, resp.. In bacterial reverse mutation assay, AMK dose-dependently increased revertant colony numbers in TA98, TA100 and TA1537 regardless of metabolic activation. AMK increased the incidence of chromosomal aberration in Chinese hamster ovary-K1 cells, but there was no statistically significant difference. The incidences of micronucleus in bone marrow erythrocyte were significantly increased in mice after oral administration of AMK (5000 mg/kg, comparing with those of vehicle group (P<0.05. The results of three standard tests suggest that the genotoxicity of AMK is directly related to the AAs contents in AMK.

Genotoxicity of unmodified and organo-modified montmorillonite

DEFF Research Database (Denmark)

Sharma, Anoop Kumar; Schmidt, Bjørn; Frandsen, Henrik Lauritz

2010-01-01

absent in the filtered samples, which was independently confirmed by dynamic light-scattering measurements. Detection and identification of free quaternary ammonium modifier in the filtered sample was carried out by HPLC-Q-TOF/MS and revealed a total concentration of a mixture of quaternary ammonium...... assay, none of the clays produced ROS in a cell-free test system (the DCFH-DA assay). Inductively coupled plasma mass-spectrometry (ICP-MS) was used to detect clay particles in the filtered samples using aluminium as a tracer element characteristic to clay. The results indicated that clay particles were...... analogues of 1.57 mu g/ml. These findings suggest that the genotoxicity of organo-modified montmorillonite was caused by the organo-modifier. The detected organo-modifier mixture was synthesized and comet-assay results showed that the genotoxic potency of this synthesized organo-modifier was in the same...

Genotoxicity Biomonitoring Along a Coastal Zone Under Influence of Offshore Petroleum Exploration (Southeastern Brazil).

Science.gov (United States)

Gutiérrez, Juan Manuel; da Conceição, Moisés Basilio; Molisani, Mauricio Mussi; Weber, Laura Isabel

2018-03-01

Offshore oil exploration creates threats to coastal ecosystems, including increasing urbanization and associated effluent releases. Genotoxicity biomarkers in mussels were determined across a gradient of coastal zone influences of offshore petroleum exploration in southeastern Brazil. Coastal ecosystems such as estuaries, beaches and islands were seasonally monitored for genotoxicity evaluation using the brown mussel Perna perna. The greatest DNA damage (5.2% ± 1.9% tail DNA and 1.5‰  ± 0.8‰ MN) were observed in urban estuaries, while Santana Archipelago showed levels of genotoxicity near zero and is considered a reference site. Mussels from urban and pristine beaches showed intermediate damage levels, but were also influenced by urbanization. Thus, mussel genotoxicity biomarkers greatly indicated the proposed oil exploration and urbanization scenarios that consequently are genetically affecting coastal organisms.

Methodological considerations for using umu assay to assess photo-genotoxicity of engineered nanoparticles

DEFF Research Database (Denmark)

Cupi, Denisa; Baun, Anders

2016-01-01

In this study we investigated the feasibility of high-throughput (96-well plate) umu assay to test the genotoxic effect of TiO2 engineered nanoparticles (ENPs) under UV light (full spectrum) and visible light (455nm). Exposure of TiO2 ENPs to up to 60min of UV light induced a photocatalytic...... production of ROS. However, UV light itself caused cytotoxic damage to Salmonella typhimurium at exposures >15min and a genotoxic effect at exposures >0.5min; and use of UV filters did not lower this effect. No genotoxicity of TiO2 ENPs was observed under visible light conditions at concentrations up to 100...

Primary genotoxicity in the liver following pulmonary exposure to carbon black nanoparticles in mice

DEFF Research Database (Denmark)

Modrzynska, Justyna; Berthing, Trine; Ravn-Haren, Gitte

2018-01-01

Background Little is known about the mechanism underlying the genotoxicity observed in the liver following pulmonary exposure to carbon black (CB) nanoparticles (NPs). The genotoxicity could be caused by the presence of translocated particles or by circulating inflammatory mediators released during...

Proteome-wide Identification of Poly(ADP-Ribosyl)ation Targets in Different Genotoxic Stress Responses

DEFF Research Database (Denmark)

Jungmichel, S.; Rosenthal, F.; Altmeyer, M.

2013-01-01

. Nuclear proteins encompassing nucleic acid binding properties are prominently PARylated upon genotoxic stress, consistent with the nuclear localization of ARTD1/PARP1 and ARTD2/PARP2. Distinct differences in proteins becoming PARylated upon various genotoxic insults are observed, exemplified...

A novel mechanism of oxidative genotoxicity

Indian Academy of Sciences (India)

The genotoxicity of reactive oxygen species (ROS) is well established. The underlying mechanism involves oxidation of DNA by ROS. However, we have recently shown that hydrogen peroxide (H2O2), the major mediator of oxidative stress, can also cause genomic damage indirectly. Thus, H2O2 at pathologically relevant ...

Distinguishing attack and second-preimage attack on encrypted message authentication codes (EMAC)

Science.gov (United States)

Ariwibowo, Sigit; Windarta, Susila

2016-02-01

In this paper we show that distinguisher on CBC-MAC can be applied to Encrypted Message Authentication Code (EMAC) scheme. EMAC scheme in general is vulnerable to distinguishing attack and second preimage attack. Distinguishing attack simulation on AES-EMAC using 225 message modifications, no collision have been found. According to second preimage attack simulation on AES-EMAC no collision found between EMAC value of S1 and S2, i.e. no second preimage found for messages that have been tested. Based on distinguishing attack simulation on truncated AES-EMAC we found collision in every message therefore we cannot distinguish truncated AES-EMAC with random function. Second-preimage attack is successfully performed on truncated AES-EMAC.

Assessing genotoxic effects in fish from a marine protected area influenced by former mining activities and other stressors

International Nuclear Information System (INIS)

Gusso-Choueri, Paloma Kachel; Choueri, Rodrigo Brasil; Santos, Gustavo Souza; Seraphim de Araújo, Giuliana; Feitosa Cruz, Ana Carolina

2016-01-01

The goal of the current study was to evaluate different genotoxicity tools in order to assess a marine protected area (MPA) affected by former mining activities and urban settlements. A catfish (Cathorops spixii) was analyzed for genotoxic effects at the (i) molecular and at the (ii) chromosomal levels. Through factor analysis, genotoxicity was found to be linked to levels of metals bioaccumulated and PAH metabolites in the bile. Micronucleus and nuclear alteration were less vulnerable to the effects of confounding factors in mildly contaminated areas since they were more frequently associated with bioaccumulated metals than the DNA analysis. The different genotoxicity responses allowed for the identification of sources of pollution in the MPA. This approach was important for detecting environmental risks related to genotoxic contaminants in a mildly contaminated MPA. -- Highlights: •We assessed genotoxicity and bioaccumulation in catfish from a marine protected area. •The area is under the influence of past mining activities and urban settlements. •Cellular level responses were highly associated with body burdens of metals and As. •Responses at the molecular level were less associated with body burdens. •Genotoxicity in different organs helped identify pollution sources in MPA.

Impacts of fullerene C60 and virgin olive oil on cadmium-induced genotoxicity in rats.

Science.gov (United States)

Aly, Fayza M; Kotb, Ahmed M; Haridy, Mohie A M; Hammad, Seddik

2018-07-15

Currently, cadmium is considered to be one of the major environmental pollutants. Environmentally, cadmium is released in various forms e.g. oxide, chloride and sulphide. The aim of the present study was to examine the genotoxic impact of fullerene nanoparticles C 60 (C 60 ) and virgin olive oil (VOO) on cadmium chloride (CdCl 2 )-induced genotoxicity in rats. To evaluate these effects on DNA damage and chromosomal frequency, 25 albino rats were randomly assigned to 5 groups (n=5 per group): Group 1 served as a control; Group 2 received a single intraperitoneal dose of CdCl 2 (3.5mg/kg); Group 3 animals were treated with C 60 (4mg/kg, orally) every other day for 20days; Group 4 received a single intraperitoneal dose of CdCl 2 (3.5mg/kg) and an oral dose of C 60 (4mg/kg); and Group 5 received a single intraperitoneal dose of CdCl 2 (3.5mg/kg) and oral doses of VOO every other day for 20 consecutive days. Genotoxic and anti-genotoxic effects of C 60 and VOO were evaluated in the liver, kidney and bone marrow using molecular and cytogenetic assays. As expected, CdCl 2 and C 60 administration was associated with band number alterations in both liver and kidney; however, C 60 pretreatment recovered to approximately basal number. Surprisingly, C 60 and VOO significantly attenuated the genotoxic effects caused by CdCl 2 in livers and kidneys. In bone marrow, in addition to a reduction in the chromosomal number, several chromosomal aberrations were caused by CdCl 2 . These chromosomal alterations were also reversed by C 60 and VOO. In conclusion, molecular and cytogenetic studies showed that C 60 and VOO exhibit anti-genotoxic agents against CdCl 2 -induced genotoxicity in rats. Further studies are needed to investigate the optimal conditions for potential biomedical applications of these anti-genotoxic agents. Copyright © 2018 Elsevier B.V. All rights reserved.

Tungsten carbide-cobalt as a nanoparticulate reference positive control in in vitro genotoxicity assays.

Science.gov (United States)

Moche, Hélène; Chevalier, Dany; Barois, Nicolas; Lorge, Elisabeth; Claude, Nancy; Nesslany, Fabrice

2014-01-01

With the increasing human exposure to nanoparticles (NP), the evaluation of their genotoxic potential is of significant importance. However, relevance for NP of the routinely used in vitro genotoxicity assays is often questioned, and a nanoparticulate reference positive control would therefore constitute an important step to a better testing of NP, ensuring that test systems are really appropriate. In this study, we investigated the possibility of using tungsten carbide-cobalt (WC-Co) NP as reference positive control in in vitro genotoxicity assays, including 2 regulatory assays, the mouse lymphoma assay and the micronucleus assay, and in the Comet assay, recommended for the toxicological evaluation of nanomedicines by the French Agency of Human Health Products (Afssaps). Through these assays, we were able to study different genetic endpoints in 2 cell types commonly used in regulatory genotoxicity assays: the L5178Y mouse lymphoma cell line and primary cultures of human lymphocytes. Our results showed that the use of WC-Co NP as positive control in in vitro genotoxicity assays was conceivable, but that different parameters have to be considered, such as cell type and treatment schedule. L5178Y mouse lymphoma cells did not provide satisfactory results in the 3 performed tests. However, human lymphocytes were more sensitive to genotoxic effects induced by WC-Co NP, particularly after a 24-h treatment in the in vitro micronucleus assay and after a 4-h treatment in the in vitro Comet assay. Under such conditions, WC-Co could be used as a nanoparticulate reference positive control in these assays.

Comet assay evaluation of six chemicals of known genotoxic potential in rats.

Science.gov (United States)

Hobbs, Cheryl A; Recio, Leslie; Streicker, Michael; Boyle, Molly H; Tanaka, Jin; Shiga, Atsushi; Witt, Kristine L

2015-07-01

As a part of an international validation of the in vivo rat alkaline comet assay (comet assay) initiated by the Japanese Center for the Validation of Alternative Methods (JaCVAM) we examined six chemicals for potential to induce DNA damage: 2-acetylaminofluorene (2-AAF), N-nitrosodimethylamine (DMN), o-anisidine, 1,2-dimethylhydrazine dihydrochloride (1,2-DMH), sodium chloride, and sodium arsenite. DNA damage was evaluated in the liver and stomach of 7- to 9-week-old male Sprague Dawley rats. Of the five genotoxic carcinogens tested in our laboratory, DMN and 1,2-DMH were positive in the liver and negative in the stomach, 2-AAF and o-anisidine produced an equivocal result in liver and negative results in stomach, and sodium arsenite was negative in both liver and stomach. 1,2-DMH and DMN induced dose-related increases in hedgehogs in the same tissue (liver) that exhibited increased DNA migration. However, no cytotoxicity was indicated by the neutral diffusion assay (assessment of highly fragmented DNA) or histopathology in response to treatment with any of the tested chemicals. Therefore, the increased DNA damage resulting from exposure to DMN and 1,2-DMH was considered to represent a genotoxic response. Sodium chloride, a non-genotoxic non-carcinogen, was negative in both tissues as would be predicted. Although only two (1,2-DMH and DMN) out of five genotoxic carcinogens produced clearly positive results in the comet assay, the results obtained for o-anisidine and sodium arsenite in liver and stomach cells are consistent with the known mode of genotoxicity and tissue specificity exhibited by these carcinogens. In contrast, given the known genotoxic mode-of-action and target organ carcinogenicity of 2-AAF, it is unclear why this chemical failed to convincingly increase DNA migration in the liver. Thus, the results of the comet assay validation studies conducted in our laboratory were considered appropriate for five out of the six test chemicals. Copyright © 2015

Genotoxic evaluation of an industrial effluent from an oil refinery using plant and animal bioassays.

Science.gov (United States)

Rodrigues, Fernando Postalli; Angeli, José Pedro Friedmann; Mantovani, Mário Sérgio; Guedes, Carmen Luisa Barbosa; Jordão, Berenice Quinzani

2010-01-01

Polycyclic aromatic hydrocarbons (PAHs) are genotoxic chemicals commonly found in effluents from oil refineries. Bioassays using plants and cells cultures can be employed for assessing environmental safety and potential genotoxicity. In this study, the genotoxic potential of an oil refinery effluent was analyzed by means of micronucleus (MN) testing of Alium cepa, which revealed no effect after 24 h of treatment. On the other hand, primary lesions in the DNA of rat (Rattus norvegicus) hepatoma cells (HTC) were observed through comet assaying after only 2 h of exposure. On considering the capacity to detect DNA damage of a different nature and of these cells to metabolize xenobiotics, we suggest the association of the two bioassays with these cell types, plant (Allium cepa) and mammal (HTC) cells, for more accurately assessing genotoxicity in environmental samples.

Exogenous spatial attention influences figure-ground assignment.

Science.gov (United States)

Vecera, Shaun P; Flevaris, Anastasia V; Filapek, Joseph C

2004-01-01

In a hierarchical stage account of vision, figure-ground assignment is thought to be completed before the operation of focal spatial attention. Results of previous studies have supported this account by showing that unpredictive, exogenous spatial precues do not influence figure-ground assignment, although voluntary attention can influence figure-ground assignment. However, in these studies, attention was not summoned directly to a region in a figure-ground display. In three experiments, we addressed the relationship between figure-ground assignment and visuospatial attention. In Experiment 1, we replicated the finding that exogenous precues do not influence figure-ground assignment when they direct attention outside of a figure-ground stimulus. In Experiment 2, we demonstrated that exogenous attention can influence figure-ground assignment if it is directed to one of the regions in a figure-ground stimulus. In Experiment 3, we demonstrated that exogenous attention can influence figure-ground assignment in displays that contain a Gestalt figure-ground cue; this result suggests that figure-ground processes are not entirely completed prior to the operation of focal spatial attention. Exogenous spatial attention acts as a cue for figure-ground assignment and can affect the outcome of figure-ground processes.

Consequences and detection of invalid exogeneity conditions

NARCIS (Netherlands)

Niemczyk, J.

2009-01-01

Estimators for econometric relationships require observations on at least as many exogenous variables as the model has unknown coefficients. This thesis examines techniques to classify variables as being either exogenous or endogenous, and investigates the consequences of invalid classifications.

Cells behaviors and genotoxicity on topological surface

International Nuclear Information System (INIS)

Yang, N.; Yang, M.K.; Bi, S.X.; Chen, L.; Zhu, Z.Y.; Gao, Y.T.; Du, Z.

2013-01-01

To investigate different cells behaviors and genotoxicity, which were driven by specific microenvironments, three patterned surfaces (pillars, wide grooves and narrow grooves) and one smooth surface were prepared by template-based technique. Vinculin is a membrane-cytoskeletal protein in focal adhesion plaques and associates with cell–cell and cell–matrix junctions, which can promote cell adhesion and spreading. The immunofluorescence staining of vinculin revealed that the narrow grooves patterned substrate was favorable for L929 cell adhesion. For cell multiplication, the narrow grooves surface was fitted for the proliferation of L929, L02 and MSC cells, the pillars surface was only in favor of L929 cells to proliferate during 7 days of cell cultivation. Cell genetic toxicity was evaluated by cellular micronuclei test (MNT). The results indicated that topological surfaces were more suitable for L929 cells to proliferate and maintain the stability of genome. On the contrary, the narrow grooves surface induced higher micronuclei ratio of L02 and MSC cells than other surfaces. With the comprehensive results of cell multiplication and MNT, it was concluded that the wide grooves surface was best fitted for L02 cells to proliferate and have less DNA damages, and the smooth surface was optimum for the research of MSC cells in vitro. - Highlights: • Different cells behaviors on microstructure surfaces were discussed in this paper. • The expression of cell protein of Vinculin was studied in this research. • Cellular micronuclei test was applied to evaluate cells' genotoxicity. • Cell genotoxicity was first studied in the research field of topological surfaces

Aporrectodea caliginosa, a suitable earthworm species for field based genotoxicity assessment?

International Nuclear Information System (INIS)

Klobucar, Goeran I.V.; Stambuk, Anamaria; Srut, Maja; Husnjak, Ivana; Merkas, Martina; Traven, Luka; Cvetkovic, Zelimira

2011-01-01

There is a growing interest for the application of biomakers to field-collected earthworms. Therefore we have evaluated the usability of native populations of endogeic, widely distributed earthworm Aporrectodea caliginosa in the assessment of soil genotoxicity using the Comet assay. Validation of the Comet assay on earthworm coelomocytes has been established using commercially available Eisenia fetida exposed to copper, cadmium, and pentachlorophenol, along with A. caliginosa exposed to copper in a filter paper contact test. Neutral red retention time (NRRT) assay was conducted on copper exposed and field-collected earthworms. Significant DNA and lysosomal damage was measured using Comet and NRRT assays in native populations of A. caliginosa sampled from the polluted soils in the urban area in comparison to the earthworms from the reference site. The results of this study confirm the employment of A. caliginosa as a suitable species for the in situ soil toxicity and genotoxicity field surveys. - Research highlights: → Native A. caliginosa has shown significant biological effect measured by the Comet and NRRT assays. → The Comet assay on A. caliginosa and E. fetida has shown to be of similar sensitivity as the NRRT assay. → A. caliginosa is a suitable species for the in situ soil toxicity and genotoxicity field surveys. - Native populations of endogeic earthworm Aporrectodea caliginosa can be successfully applied in the genotoxicity field surveys using Comet assay.

Aporrectodea caliginosa, a suitable earthworm species for field based genotoxicity assessment?

Energy Technology Data Exchange (ETDEWEB)

Klobucar, Goeran I.V., E-mail: gklobuca@zg.biol.pmf.hr [Department of Zoology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb (Croatia); Stambuk, Anamaria; Srut, Maja [Department of Zoology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb (Croatia); Husnjak, Ivana [Ministry of Environmental Protection, Physical Planning and Construction, Ulica Republike Austrije 14, Zagreb (Croatia); Merkas, Martina [Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10000 Zagreb (Croatia); Traven, Luka [Department of Environmental Medicine, Medical Faculty, University of Rijeka, Brace Branchetta 20a, 51000 Rijeka (Croatia); Teaching Institute of Public Health of the Primorsko-goranska County, Kresimirova 52a, 51000 Rijeka (Croatia); Cvetkovic, Zelimira [Department of Ecology, Institute of Public Health, Mirogojska c. 16, 10000 Zagreb (Croatia)

2011-04-15

There is a growing interest for the application of biomakers to field-collected earthworms. Therefore we have evaluated the usability of native populations of endogeic, widely distributed earthworm Aporrectodea caliginosa in the assessment of soil genotoxicity using the Comet assay. Validation of the Comet assay on earthworm coelomocytes has been established using commercially available Eisenia fetida exposed to copper, cadmium, and pentachlorophenol, along with A. caliginosa exposed to copper in a filter paper contact test. Neutral red retention time (NRRT) assay was conducted on copper exposed and field-collected earthworms. Significant DNA and lysosomal damage was measured using Comet and NRRT assays in native populations of A. caliginosa sampled from the polluted soils in the urban area in comparison to the earthworms from the reference site. The results of this study confirm the employment of A. caliginosa as a suitable species for the in situ soil toxicity and genotoxicity field surveys. - Research highlights: > Native A. caliginosa has shown significant biological effect measured by the Comet and NRRT assays. > The Comet assay on A. caliginosa and E. fetida has shown to be of similar sensitivity as the NRRT assay. > A. caliginosa is a suitable species for the in situ soil toxicity and genotoxicity field surveys. - Native populations of endogeic earthworm Aporrectodea caliginosa can be successfully applied in the genotoxicity field surveys using Comet assay.

Cooperating attackers in neural cryptography.

Science.gov (United States)

Shacham, Lanir N; Klein, Einat; Mislovaty, Rachel; Kanter, Ido; Kinzel, Wolfgang

2004-06-01

A successful attack strategy in neural cryptography is presented. The neural cryptosystem, based on synchronization of neural networks by mutual learning, has been recently shown to be secure under different attack strategies. The success of the advanced attacker presented here, called the "majority-flipping attacker," does not decay with the parameters of the model. This attacker's outstanding success is due to its using a group of attackers which cooperate throughout the synchronization process, unlike any other attack strategy known. An analytical description of this attack is also presented, and fits the results of simulations.

Crony Attack: Strategic Attack’s Silver Bullet

Science.gov (United States)

2006-11-01

physical assets or financial assets. The form of crony attack that most closely resembles classic strategic attack is to deny, degrade, or destroy a money...February 1951. Reprinted in Airpower Studies Coursebook , Air Command and Staff College, Maxwell AFB, AL, 2002, 152–58. Hirsch, Michael. “NATO’s Game of

Genotoxicity studies in semiconductor industry. 1. In vitro mutagenicity and genotoxicity studies of waste samples resulting from plasma etching

Energy Technology Data Exchange (ETDEWEB)

Braun, R.; Huettner, E.M.; Merten, H.; Raabe, F. (Institute of Plant Genetics and Crop Plant Research, Gatersleben (Germany))

1993-07-01

Solid waste samples taken from the etching reactor, the turbo pump, and the waste air system of a plasma etching technology line in semiconductor production were studied as to their genotoxic properties in a bacterial repair test, in the Ames/Salmonella microsome assay, in the SOS chromotest, in primary mouse hepatocytes, and in Chinese hamster V79 cell cultures. All three waste samples were found to be active by inducing of unscheduled DNA-synthesis in mouse hepatocytes in vitro. In the bacterial rec-type repair test with Proteus mirabilis, waste samples taken from the turbo pump and the vacuum pipe system were not genotoxic. The waste sample taken from the chlorine-mediated plasma reactor was clearly positive in the bacterial repair assay and in the SOS chromotest with Escherichia coli. Mutagenic activity was demonstrated for all samples in the presence and absence of S9 mix made from mouse liver homogenate. Again, highest mutagenic activity was recorded for the waste sample taken from the plasma reactor, while samples collected from the turbo pump and from the waste air system before dilution and liberation of the air were less mutagenic. For all samples chromosomal damage in V79 cells was not detected, indicating absence of clastogenic activity in vitro. Altogether, these results indicate generation of genotoxic and mutagenic products as a consequence of chlorine-mediated plasma etching in the microelectronics industry and the presence of genotoxins even in places distant from the plasma reactor. Occupational exposure can be expected both from the precipitated wastes and from chemicals reaching the environment with the air stream.

Cytotoxic and genotoxic potential of food-borne nitriles in a liver in vitro model

Science.gov (United States)

Kupke, Franziska; Herz, Corinna; Hanschen, Franziska S.; Platz, Stefanie; Odongo, Grace A.; Helmig, Simone; Bartolomé Rodríguez, María M.; Schreiner, Monika; Rohn, Sascha; Lamy, Evelyn

2016-01-01

Isothiocyanates are the most intensively studied breakdown products of glucosinolates from Brassica plants and well recognized for their pleiotropic effects against cancer but also for their genotoxic potential. However, knowledge about the bioactivity of glucosinolate-borne nitriles in foods is very poor. As determined by GC-MS, broccoli glucosinolates mainly degrade to nitriles as breakdown products. The cytotoxicity of nitriles in human HepG2 cells and primary murine hepatocytes was marginal as compared to isothiocyanates. Toxicity of nitriles was not enhanced in CYP2E1-overexpressing HepG2 cells. In contrast, the genotoxic potential of nitriles was found to be comparable to isothiocyanates. DNA damage was persistent over a certain time period and CYP2E1-overexpression further increased the genotoxic potential of the nitriles. Based on actual in vitro data, no indications are given that food-borne nitriles could be relevant for cancer prevention, but could pose a certain genotoxic risk under conditions relevant for food consumption. PMID:27883018

Modulation of mitomycin C-induced genotoxicity by acetyl- and thio- analogues of salicylic acid.

Science.gov (United States)

Pawar, Amol Ashok; Vikram, Ajit; Tripathi, Durga Nand; Padmanabhan, Shweta; Ramarao, Poduri; Jena, Gopabandhu

2009-01-01

Recent reports regarding acetylsalicylic acid (ASA) and its metabolites suggest suppressive effects against mitomycin C (MMC)-induced genotoxicity in a mice chromosomal aberration assay. Keeping this in mind, the potential anti-genotoxic effect of the thio-analogue of salicylic acid namely thio-salicylic acid (TSA) was speculated upon. The present study investigated and compared the anti-genotoxic potential of ASA and TSA. The study was performed in male swiss mice (20+/-2 g) using single-cell gel electrophoresis and a peripheral blood micronucleus assay. ASA and TSA (5, 10 or 20 mg/kg) were administered 15 minutes after MMC (1 mg/kg) once daily for 3 or 7 days. Both ASA and TSA significantly decreased the DNA damage induced by MMC as indicated by a decrease in the comet parameters in bone marrow cells and decreased frequencies of micronucleated reticulocytes in peripheral blood. The results clearly demonstrate the anti-genotoxic potential of ASA and TSA.

In Vitro Genotoxic Effects of Four Helichrysum Species in Human Lymphocytes Cultures

OpenAIRE

Erolu, Erhan H; Hamzaolu, Ergin; Aksoy, Ahmet; Budak, Ümit; Özkul, Yusuf

2010-01-01

Helichrysum sanguineum, Helichrysum pamphylicum, Helichrysum orientale, Helichrysum noeanum (Asteraceae) are medicinal plants. For centuries, they have been used as tea in Turkey because of their medicinal properties. So far no scientifc evidence has been found in a literature survey regarding the genotoxic effects of these plants. This work evaluated the genotoxic effects on human lymphocyte cultures induced by methanol extracts of these plants, assayed in different concentrations (0.01, 0.0...

Genotoxicity assessment data for exfoliated buccal cells exposed to mobile phone radiation

Directory of Open Access Journals (Sweden)

F.M. de Oliveira

2017-12-01

Full Text Available Healthy mobile phone users aged 18–30 y.o. provided exfoliated buccal cells samples from the right and left inner cheeks. A total of 2000 cells per subject were screened for the presence of micronuclei as a sign of genotoxic damage, according to the mobile phone use profile of each user. Keywords: Electromagnetic fields, Mobile phones, Genotoxicity, Micronuclei, Exfoliated buccal cells, Feulgen stain

International Environmental Agreements with Endogenous or Exogenous Risk

OpenAIRE

Fuhai Hong; Larry Karp

2014-01-01

We examine the effect of endogenous and exogenous risk on the equilibrium (expected) membership of an International Environmental Agreement when countries are risk averse. Endogenous risk arises when countries use mixed rather than pure strategies at the participation game, and exogenous risk arises from the inherent uncertainty about the costs and benefits of increased abate- ment. Under endogenous risk, an increase in risk aversion increases expected participation. Under exogenous risk and ...

Mutagenic and genotoxic activity of particulate matter MP2,5, in Pamplona, North Santander, Colombia

Directory of Open Access Journals (Sweden)

Martínez Montañez, Mónica Liseth

2012-10-01

Full Text Available Objective: To study the mutagenic and genotoxic activities of particulate material (MP2,5 collected in Pamplona, Norte de Santander, Colombia.Materials and methods: MP2,5 was monitored by means of a Partisol 2025 sequential air sampler with Plus Palmflex quartz filters. The latter were subjected to two extraction procedures: Soxhlet extraction using dichloromethane-acetone; and ultrasonic extraction using dichloromethane, acetone and dichloromethane/ acetone mix. The mutagenic and genotoxic activities were determined for each extract.Results: This is the first study conducted in Colombia that reports the mutagenic and genotoxic activities associated with particulate matter (MP2,5 taken from vehicular emissions in Pamplona, Norte de Santander. The mutagenic assay determined by the Ames test using Salmonella typhimurium strains TA98 and TA100 showed a high direct mutagenic activity in the analyzed extracts. On the other hand, the genotoxic activity, determined by means of the comet assay, was high too.Conclusion: Particulate material (MP2,5 present in air samples in Pamplona (northeastern Colombia is a risk factor for the exposed population because it can directly induce mutations and also cause genotoxic damage.

Genotoxic effect of radio marked lymphocytes using Tc-99m complexes

International Nuclear Information System (INIS)

Pedraza L, M.; Ferro F, G.; Mendiola C, M.T.; Morales R, P.

1997-01-01

The genotoxic effect of radio marked lymphocytes was evaluated using 99m -Tc-HMPAO and 99m -Tc- gentisic acid complexes. With the results of this work it is pretended to contribute to the knowledge of genetic and structural damages that provokes the radiation in the marked lymphocytes. The d, 1-HMPAO was synthesized in laboratory with a yielding of 30 %. The radiochemical purity of the complexes was greater than 85%. Mouse lymphocytes obtained of sanguineous volumes 2 ml were used. The radio marked efficiency of cells was 19.6 ± 6.4% and 25.6 ± 5.8% for 99m Tc-HMPAO and 99m Tc gentisic acid respectively. The genotoxic effect was evaluated using the technique of Unicellular Electrophoresis in Micro gel (Comet assay). The results showed that both 99m Tc complexes produce genotoxicity due to their capacity to penetrate cells, therefore the Auger and M internal conversion electrons place all their energy obtaining doses of Gray order. (Author)

Genotoxic evaluation of an industrial effluent from an oil refinery using plant and animal bioassays

Directory of Open Access Journals (Sweden)

Fernando Postalli Rodrigues

2010-01-01

Full Text Available Polycyclic aromatic hydrocarbons (PAHs are genotoxic chemicals commonly found in effluents from oil refineries. Bioassays using plants and cells cultures can be employed for assessing environmental safety and potential genotoxicity. In this study, the genotoxic potential of an oil refinery effluent was analyzed by means of micronucleus (MN testing of Alium cepa, which revealed no effect after 24 h of treatment. On the other hand, primary lesions in the DNA of rat (Rattus norvegicus hepatoma cells (HTC were observed through comet assaying after only 2 h of exposure. On considering the capacity to detect DNA damage of a different nature and of these cells to metabolize xenobiotics, we suggest the association of the two bioassays with these cell types, plant (Allium cepa and mammal (HTC cells, for more accurately assessing genotoxicity in environmental samples.

VEGF-A is increased in exogenous endophthalmitis.

Science.gov (United States)

Seamone, Mark E; Lewis, Darrell R; Haidl, Ian D; Gupta, R Rishi; O' Brien, Daniel M; Dickinson, John; Samad, Arif; Marshall, Jean S; Cruess, Alan F

2017-06-01

Exogenous endophthalmitis is an ophthalmologic emergency defined by panocular inflammation. Vascular endothelial growth factor A (VEGF-A) contributes to inflammation by promoting chemotaxis of monocytes and granulocytes and by increasing vascular permeability. The purpose of this article is to determine if VEGF-A is elevated in the vitreous samples obtained from individuals with exogenous endophthalmitis. Vitreous samples from individuals with exogenous endophthalmitis (n = 18) were analyzed via Luminex assay and enzyme-linked immunosorbent assay for the cytokines VEGF-A, tumor necrosis factor (TNF), interleukin 6 (IL-6), IL-8 (chemokine [CXCL]-8), IL-1β, IL-10, IL-12p70, IL-33, interferon (IFN)-γ, IFN-α, IFN-β, chemokine ligand (CCL)-3, IL-2, IL-5, IL-15, CXCL-10, CCL-2, IL-1Ra, CCL-5, IL-17, and CCL-11. Vitreous samples obtained at the time of macular hole surgery served as controls (n = 8). Concentrations of VEGF-A were significantly elevated in vitreous samples from individuals with exogenous endophthalmitis compared with macular hole (p exogenous endophthalmitis after cataract surgery (p = 0.001), vitrectomy (p = 0.024), and intravitreal injection (p = 0.012). VEGF-A concentrations were similar in both culture-positive and culture-negative populations (p > 0.05). In a linear regression model, levels of VEGF-A correlated significantly with the chemokine CXCL-8 (p = 0.028). We demonstrate that VEGF-A is potently upregulated in exogenous endophthalmitis. This observation provides a foundation for future studies of targeted VEGF-A blockade in the management of endophthalmitis. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Conventional and whitening toothpastes: cytotoxicity, genotoxicity and effect on the enamel surface.

Science.gov (United States)

Camargo, Samira Esteves Afonso; Jóias, Renata Pilli; Santana-Melo, Gabriela Fátima; Ferreira, Lara Tolentino; El Achkar, Vivian Narana Ribeiro; Rode, Sigmar de Mello

2014-12-01

To evaluate the cytotoxicity and genotoxicity of whitening and common toothpastes, and the surface roughness of tooth enamel submitted to brushing with both toothpastes. Samples of whitening toothpastes [Colgate Whitening (CW) and Oral-B Whitening (OBW)] and regular (non-whitening) toothpastes (Colgate and Oral-B) were extracted in culture medium. Gingival human fibroblasts (FMM-1) were placed in contact with different dilutions of culture media that had been previously exposed to such materials, and the cytotoxicity was evaluated using the MTT assay. The genotoxicity was assessed by the micronucleus formation assay in Chinese hamster fibroblasts (V79). The cell survival rate and micronuclei number were assessed before and after exposure to the toothpaste extracts. For the surface roughness evaluation, 20 bovine tooth specimens, divided into four groups according to toothpastes, were submitted to 10,000 brushing cycles. The results were analyzed using the Mann-Whitney U and two-way ANOVA tests (P whitening toothpastes showed the highest numbers of micronuclei compared to the untreated control (UC) (P enamel surface (P whitening toothpastes and Oral-B were cytotoxic to the cells. The whitening toothpastes were more genotoxic to cells in vitro than the common toothpastes, and genotoxicity was more pronounced in the OBW toothpaste.

Genotoxic evaluation of terbinafine in human lymphocytes in vitro.

Science.gov (United States)

Tolomeotti, Danielle; de Castro-Prado, Marialba Avezum Alves; de Sant'Anna, Juliane Rocha; Martins, Ana Beatriz Tozzo; Della-Rosa, Valter Augusto

2015-01-01

Terbinafine is an antimycotic drug usually used against several superficial fungal infections and with a potential application in the treatment of human cancers. Since to date there are few data on the genotoxic effects of terbinafine in mammalian cells, current study evaluated the potential genotoxic of such antifungal agent in cultured human peripheral blood lymphocytes. Terbinafine was used at the peak plasma concentration (1.0 μg/ml) and in four additional concentrations higher than the human plasmatic peak (5.0 μg/ml, 25.0 μg/ml, 50.0 μg/ml and 100.0 μg/ml). Chromosomal aberrations (CA), sister chromatid exchanges (SCE), micronuclei (MN), nucleoplasmic bridges (NP) and nuclear buds (NB) were scored as genetic endpoints. In all analysis no significant differences (α = 0.05, Kruskal-Wallis test) were observed. Complementary criterion adopted to obtain the final response in cytogenetic agreed with statistical results. Therefore, results of this study showed that terbinafine neither induced CA, SCE, MN, NP and NB nor affected significantly mitotic, replication and cytokinesis-block proliferation indices in any of the tested concentrations. It may be assumed that terbinafine was not genotoxic or cytotoxic to cultured human peripheral blood lymphocytes in our experimental conditions.

Composite Dos Attack Model

Directory of Open Access Journals (Sweden)

Simona Ramanauskaitė

2012-04-01

Full Text Available Preparation for potential threats is one of the most important phases ensuring system security. It allows evaluating possible losses, changes in the attack process, the effectiveness of used countermeasures, optimal system settings, etc. In cyber-attack cases, executing real experiments can be difficult for many reasons. However, mathematical or programming models can be used instead of conducting experiments in a real environment. This work proposes a composite denial of service attack model that combines bandwidth exhaustion, filtering and memory depletion models for a more real representation of similar cyber-attacks. On the basis of the introduced model, different experiments were done. They showed the main dependencies of the influence of attacker and victim’s properties on the success probability of denial of service attack. In the future, this model can be used for the denial of service attack or countermeasure optimization.

Exogenous melatonin administration is beneficial for male ...

African Journals Online (AJOL)

ABSTRACT. Background: A concern in the use of exogenous melatonin as a therapeutic intervention is that it may interfere with reproductive function. Herein, we report that chronic exogenous melatonin administration does not impair male reproductive function during ageing and at old age in male Sprague Dawley rats.

The Endogenous-Exogenous Partition in Attribution Theory

Science.gov (United States)

Kruglanski, Arie W.

1975-01-01

Within lay explanation of actions, several significant inferences are assumed to follow from the partition between endogenous and exogenous attributions. An endogenous action is judged to constitute an end in itself; an exogenous action is judged to serve as a means to some further end. (Editor/RK)

CENTRAL SEROUS CHORIORETINOPATHY IN POSTMENOPAUSAL WOMEN RECEIVING EXOGENOUS TESTOSTERONE.

Science.gov (United States)

Conway, Mandi D; Noble, Jason A; Peyman, Gholam A

2017-01-01

Central serous chorioretinopathy (CSR) is a serous detachment of the neurosensory retina commonly associated with male sex, Type-A personality and corticosteroid use. Exogenous administration of androgens and development of CSR in men has been reported. Only one case of CSR in a postmenopausal woman receiving exogenous androgen therapy has been reported. The authors describe three cases of chronic CSR in postmenopausal women receiving exogenous testosterone therapy. Diagnosis was based on characteristic clinical, fluorescein angiographic, and optical coherence tomography findings. The three women were being treated with exogenous testosterone and progesterone therapy for symptoms of menopause and libido loss. Average age at presentation was 54.7 years (53-56 years), average duration of exogenous androgen use was 61 months (36-87 months), with average 19.7-month follow-up. Resolution of symptoms seemed correlated with cessation of androgen use despite treatment with oscillatory photodynamic therapy and intravitreal pharmacotherapy with antivascular endothelial growth factor agents. Exogenous testosterone is increasingly prescribed for menopausal symptoms and libido loss. Treatment with oscillatory photodynamic therapy, supplemental bevacizumab intravitreal pharmacotherapy, and cessation of exogenous androgen therapy was successful in three cases of chronic, therapy-resistant CSR. Ophthalmologists should inquire about androgen usage in patients who present with CSR, especially in the setting of therapy resistance.

Size- and coating-dependent cytotoxicity and genotoxicity of silver nanoparticles evaluated using in vitro standard assays.

Science.gov (United States)

Guo, Xiaoqing; Li, Yan; Yan, Jian; Ingle, Taylor; Jones, Margie Yvonne; Mei, Nan; Boudreau, Mary D; Cunningham, Candice K; Abbas, Mazhar; Paredes, Angel M; Zhou, Tong; Moore, Martha M; Howard, Paul C; Chen, Tao

2016-11-01

The physicochemical characteristics of silver nanoparticles (AgNPs) may greatly alter their toxicological potential. To explore the effects of size and coating on the cytotoxicity and genotoxicity of AgNPs, six different types of AgNPs, having three different sizes and two different coatings, were investigated using the Ames test, mouse lymphoma assay (MLA) and in vitro micronucleus assay. The genotoxicities of silver acetate and silver nitrate were evaluated to compare the genotoxicity of nanosilver to that of ionic silver. The Ames test produced inconclusive results for all types of the silver materials due to the high toxicity of silver to the test bacteria and the lack of entry of the nanoparticles into the cells. Treatment of L5718Y cells with AgNPs and ionic silver resulted in concentration-dependent cytotoxicity, mutagenicity in the Tk gene and the induction of micronuclei from exposure to nearly every type of the silver materials. Treatment of TK6 cells with these silver materials also resulted in concentration-dependent cytotoxicity and significantly increased micronucleus frequency. With both the MLA and micronucleus assays, the smaller the AgNPs, the greater the cytotoxicity and genotoxicity. The coatings had less effect on the relative genotoxicity of AgNPs than the particle size. Loss of heterozygosity analysis of the induced Tk mutants indicated that the types of mutations induced by AgNPs were different from those of ionic silver. These results suggest that AgNPs induce cytotoxicity and genotoxicity in a size- and coating-dependent manner. Furthermore, while the MLA and in vitro micronucleus assay (in both types of cells) are useful to quantitatively measure the genotoxic potencies of AgNPs, the Ames test cannot.

In vivo micronucleus test as a biomarker of genotoxicity in free-range goats from suspected contaminated environment

Directory of Open Access Journals (Sweden)

Afusat Jagun Jubril

2017-09-01

Conclusion: The finding indicates the prevalence and frequency of micronucleus as a biomarker of genotoxicity and an indicator of exposure to environmental genotoxic subtances. Hence, this highlights the relevance of these goats as important sentinel animal model. These findings, therefore, serve as a preliminary data for further studies on the latent genotoxic environmental contaminants and their potential deleterious impact. [J Adv Vet Anim Res 2017; 4(3.000: 281-287

Genotoxic Effect of Atrazine, Arsenic, Cadmium and Nitrate ...

African Journals Online (AJOL)

Atrazine has clastogenic effects and may also act as tumor promoter as it induces the aromatase enzyme. ... bladder cancer. This study ... in MCF-10A cells, suggesting that estrogen receptor modulated the genotoxicity of estrogen. Cd caused ...

Cytotoxicity and genotoxicity of intravitreal adalimumab administration in rabbit retinal cells

Directory of Open Access Journals (Sweden)

Álcio Coutinho de Paula

2015-04-01

Full Text Available Purpose: To assess the cytotoxicity and genotoxicity of intravitreal adalimumab treatment in an animal experimental model using cytological and molecular techniques. Methods: Eighteen rabbits were randomly assigned to three groups: control, adalimumab treatment, and placebo. Cytotoxicity on retinal cells was evaluated using flow cytometry assays to determine the level of apoptosis and necrosis. Genotoxicity was evaluated by comet assays to assess DNA damage, and quantitative real-time polymerase chain reaction (qPCR was used to evaluate expression of apoptosis-inducing caspases (8 and 3. Results: No cytotoxicity or genotoxicity was observed in any of the two treatment groups (adalimumab and placebo following intravitreal administration compared with the control group. Flow cytometry analysis revealed that more than 90% of the cells were viable, and only a low proportion of retinal cells presented apoptotic (~10% or necrotic (<1% activity across all groups. Molecular damage was also low with a maximum of 6.4% DNA degradation observed in the comet assays. In addition, no increase in gene expression of apoptosis-inducing caspases was observed on retinal cells by qPCR in both the adalimumab and placebo groups compared with the control group. Conclusion: The use of adalimumab resulted in no detectable cytotoxicity or genotoxicity on retinal cells for up to 60 days upon administration. These results therefore indicate that adalimumab may be a safe option for intravitreal application to treat ocular inflammatory diseases in which TNF-α is involved.

Exogenous melatonin administration is beneficial for male ...

African Journals Online (AJOL)

Background: A concern in the use of exogenous melatonin as a therapeutic intervention is that it may interfere with reproductive function. Herein, we report that chronic exogenous melatonin administration does not impair male reproductive function during ageing and at old age in male Sprague Dawley rats. Methods: ...

Genotoxicity evaluation of dental restoration nanocomposite using comet assay and chromosome aberration test

International Nuclear Information System (INIS)

Musa, Marahaini; Ponnuraj, Kannan Thirumulu; Mohamad, Dasmawati; Rahman, Ismail Ab

2013-01-01

Nanocomposite is used as a dental filling to restore the affected tooth, especially in dental caries. The dental nanocomposite (KelFil) for tooth restoration used in this study was produced by the School of Dental Sciences, Universiti Sains Malaysia, Malaysia and is incorporated with monodispersed, spherical nanosilica fillers. The aim of the study was to determine the genotoxic effect of KelFil using in vitro genotoxicity tests. The cytotoxicity and genotoxicity of KelFil was evaluated using MTT assay, comet assay and chromosome aberration tests with or without the addition of a metabolic activation system (S9 mix), using the human lung fibroblast cell line (MRC-5). Concurrent negative and positive controls were included. In the comet assay, no comet formation was found in the KelFil groups. There was a significant difference in tail moment between KelFil groups and positive control (p < 0.05). Similarly, no significant aberrations in chromosomes were noticed in KelFil groups. The mitotic indices of treatment groups and negative control were significantly different from positive controls. Hence, it can be concluded that the locally produced dental restoration nanocomposite (KelFil) is non-genotoxic under the present test conditions. (paper)

Genotoxicity and cytotoxicity induced by eluates from orthodontic glass ionomer cements in vitro

Directory of Open Access Journals (Sweden)

Fernanda Angelieri

2018-01-01

Full Text Available The aim of this study was to investigate genotoxicity and cytotoxicity of some orthodontic glass ionomer cements commercially available by means of the single cell gel (comet assay. For this purpose, five commercial orthodontic glass ionomer cements (Vidrion C®, Meron®, Optiband®, Multicure® and Ultra Band Lok® were tested in murine fibroblasts in vitro. For this purpose, eluates from each cement were prepared according manufactures instructions at 0, 2, 4, 8, 18, 32 and 64 days of immersion in artificial saliva at 37 °C. All orthodontic glass ionomer cements failed to induce cytotoxicity to murine fibroblasts for all periods evaluated in this study. However, Vidrion C® was able to induce genotoxicity after 64 days of exposure to eluates. Meron® also demonstrated genotoxicity as depicted by increasing DNA damage on 2nd day. Multicure® demonstrated genotoxicity on 32nd day and Ultra band Lok on 18th, 32nd days of exposure. Taken together, our results demonstrated that orthodontic cements derived from resin-modified glass ionomer composite (Multicure® and compomer (Ultra Band Lok® cause genetic damage in mammalian cells in vitro.

Interaction between endogenous and exogenous orienting in crossmodal attention.

Science.gov (United States)

Chen, Xiaoxi; Chen, Qi; Gao, Dingguo; Yue, Zhenzhu

2012-08-01

Using a cue-target paradigm, we investigated the interaction between endogenous and exogenous orienting in cross-modal attention. A peripheral (exogenous) cue was presented after a central (endogenous) cue with a variable time interval. The endogenous and exogenous cues were presented in one sensory modality (auditory in Experiment 1 and visual in Experiment 2) whereas the target was presented in another modality. Both experiments showed a significant endogenous cuing effect (longer reaction times in the invalid condition than in the valid condition). However, exogenous cuing produced a facilitatory effect in both experiments in response to the target when endogenous cuing was valid, but it elicited a facilitatory effect in Experiment 1 and an inhibitory effect in Experiment 2 when endogenous cuing was invalid. These findings indicate that endogenous and exogenous cuing can co-operate in orienting attention to the crossmodal target. Moreover, the interaction between endogenous and exogenous orienting of attention is modulated by the modality between the cue and the target. © 2012 The Authors. Scandinavian Journal of Psychology © 2012 The Scandinavian Psychological Associations.

Induction of micronuclei by 2-hydroxypyridine in water and elimination of solution genotoxicity by UVC (254 nm) photolysis

International Nuclear Information System (INIS)

Skoutelis, Charalambos G.; Vlastos, Dimitris; Kortsinidou, Marianna C.; Theodoridis, Ioannis T.; Papadaki, Maria I.

2011-01-01

Highlights: ► 2-Hydroxypyridine (2-HPY) is the major metabolite of 2-halogenated pyridines photolysis. ► We examine the genotoxicity of 2-HPY in cultured human lymphocytes applying the micronucleus assay. ► 2-HPY was found to be genotoxic. ► Aqueous solutions of 2-HPY were irradiated by UV at 254 nm. ► Solution genotoxicity can be completely removed after prolonged phototreatment. - Abstract: 2-Hydroxypyridine (2-HPY) is a major first-stage product formed upon the photolytic destruction of 2-halogenated pyridines. Genotoxicity of 2-HPY in water was studied as a function of concentration. Aqueous solutions of 2-HPY were irradiated by ultraviolet (UV) at 254 nm. 2-HPY concentration, solution total organic carbon (TOC) concentration and solution genotoxicity were measured as a function of treatment time and their profile as a function of time is presented in this work. 2-HPY was found to be genotoxic at all concentrations in the range of 5–400 μg ml −1 . 2-HPY mineralises completely upon prolonged UV irradiation. All untreated and irradiated solution samples, taken at different photo-treatment times, were tested in cultured human lymphocytes applying the cytokinesis block micronucleus (CBMN) assay. The genotoxicity of the solution was reduced near to the control level after prolonged UV irradiation.

Three-Dimensional, Transgenic Cell Models to Quantify Space Genotoxic Effects

Science.gov (United States)

Gonda, S. R.; Sognier, M. A.; Wu, H.; Pingerelli, P. L.; Glickman, B. W.; Dawson, David L. (Technical Monitor)

1999-01-01

The space environment contains radiation and chemical agents known to be mutagenic and carcinogenic to humans. Additionally, microgravity is a complicating factor that may modify or synergize induced genotoxic effects. Most in vitro models fail to use human cells (making risk extrapolation to humans more difficult), overlook the dynamic effect of tissue intercellular interactions on genotoxic damage, and lack the sensitivity required to measure low-dose effects. Currently a need exists for a model test system that simulates cellular interactions present in tissue, and can be used to quantify genotoxic damage induced by low levels of radiation and chemicals, and extrapolate assessed risk to humans. A state-of-the-art, three-dimensional, multicellular tissue equivalent cell culture model will be presented. It consists of mammalian cells genetically engineered to contain multiple copies of defined target genes for genotoxic assessment,. NASA-designed bioreactors were used to coculture mammalian cells into spheroids, The cells used were human mammary epithelial cells (H184135) and Stratagene's (Austin, Texas) Big Blue(TM) Rat 2 lambda fibroblasts. The fibroblasts were genetically engineered to contain -a high-density target gene for mutagenesis (60 copies of lacl/LacZ per cell). Tissue equivalent spheroids were routinely produced by inoculation of 2 to 7 X 10(exp 5) fibroblasts with Cytodex 3 beads (150 micrometers in diameter). at a 20:1 cell:bead ratio, into 50-ml HARV bioreactors (Synthecon, Inc.). Fibroblasts were cultured for 5 days, an equivalent number of epithelial cells added, and the fibroblast/epithelial cell coculture continued for 21 days. Three-dimensional spheroids with diameters ranging from 400 to 600 micrometers were obtained. Histological and immunohistochemical Characterization revealed i) both cell types present in the spheroids, with fibroblasts located primarily in the center, surrounded by epithelial cells; ii) synthesis of extracellular matrix

Heart Attack Recovery FAQs

Science.gov (United States)

... recommendations to make a full recovery. View an animation of a heart attack . Heart Attack Recovery Questions ... Support Network Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Heart Attack Symptoms ...

Acute toxicity and genotoxic activity of avocado seed extract (Persea americana Mill., c.v. Hass).

Science.gov (United States)

Padilla-Camberos, Eduardo; Martínez-Velázquez, Moisés; Flores-Fernández, José Miguel; Villanueva-Rodríguez, Socorro

2013-01-01

The use of vegetal extracts requires toxicological and genotoxic evaluations to establish and verify safety before being added to human cosmetic, pharmaceutical medicine, or alimentary products. Persea americana seeds have been used in traditional medicine as treatment for several diseases. In this work, the ethanolic seed extract of Persea americana was evaluated with respect to its genotoxic potential through micronucleus assay in rodents. The frequency of micronuclei in groups of animals treated with avocado seed extract showed no differences compared to the negative control (vehicle); therefore, it is considered that the avocado seed extract showed no genotoxic activity in the micronucleus test.

Non-genotoxic carcinogens: early effects on gap junctions, cell proliferation and apoptosis in the rat

International Nuclear Information System (INIS)

Mally, Angela; Chipman, James Kevin

2002-01-01

Non-genotoxic carcinogens are thought to induce tumour formation by disturbing the balance between cell growth and cell death. Gap junctions (GJ) contribute to the maintenance of tissue homeostasis by allowing the intercellular exchange of growth regulatory signals and potential inhibition of GJ intercellular communication through loss of connexin (Cx) plaques has been shown to be involved in the cancer process. We have investigated the time- and dose-dependent effects of the non-genotoxic hepatocarcinogens Wy-14,643, 2,3,7,8-tetrachlorodibenzo-p-dioxin, methapyrilene and hexachlorobenzene and the male rat kidney carcinogens chloroform, p-dichlorobenzene and d-limonene on gap junction plaque expression in relation to proliferation and apoptosis. With the exception of limonene, all non-genotoxic carcinogens significantly reduced the expression of GJ plaques containing Cx32 in their respective target tissue. No dose-dependent, significant effects were seen in non-target organs. Although alteration of Cx32 expression did not appear to correlate with induction of cell proliferation, out data suggest that the interaction of both processes--interference of GJ coupled with a proliferative stimulus (at the carcinogenic dose)--may be important in non-genotoxic carcinogenesis and provide a potential alert for non-genotoxic carcinogens in short-term toxicity tests

In vitro genotoxic effects of four Helichrysum species in human lymphocytes cultures.

Science.gov (United States)

Erolu, Erhan H; Hamzaolu, Ergin; Aksoy, Ahmet; Budak, Ümit; Özkul, Yusuf

2010-01-01

Helichrysum sanguineum, Helichrysum pamphylicum, Helichrysum orientale, Helichrysum noeanum (Asteraceae) are medicinal plants. For centuries, they have been used as tea in Turkey because of their medicinal properties. So far no scientific evidence has been found in a literature survey regarding the genotoxic effects of these plants. This work evaluated the genotoxic effects on human lymphocyte cultures induced by methanol extracts of these plants, assayed in different concentrations (0.01, 0.05, 0.1, 0.5 and 1 mg/mL). According to the results, Helichrysum noeanum, Helichrysum pamphylicum and Helichrysum sanguineum induced the formation of micronuclei and decreased the mitotic and replication indexes. Helichrysum orientale did not affect these parameters, whereas Helichrysum noeanum, Helichrysum pamphylicum and Helichrysum sanguineum were clearly genotoxic. They should therefore not be used freely in alternative medicine, although their antiproliferative activity may suggest antimitotic and anticarcinogenic properties. Helichrysum orientale could be used in alternative medicine.

Genotoxicity of gemfibrozil in the gilthead seabream (Sparus aurata).

Science.gov (United States)

Barreto, A; Luis, L G; Soares, A M V M; Paíga, P; Santos, L H M L M; Delerue-Matos, C; Hylland, K; Loureiro, S; Oliveira, M

2017-09-01

Widespread use of pharmaceuticals and suboptimal wastewater treatment have led to increased levels of these substances in aquatic ecosystems. Lipid-lowering drugs such as gemfibrozil, which are among the most abundant human pharmaceuticals in the environment, may have deleterious effects on aquatic organisms. We examined the genotoxicity of gemfibrozil in a fish species, the gilthead seabream (Sparus aurata), which is commercially important in southern Europe. Following 96-h waterborne exposure, molecular (erythrocyte DNA strand breaks) and cytogenetic (micronuclei and other nuclear abnormalities in cells) endpoints were measured. Gemfibrozil was positive in both endpoints, at environmentally relevant concentrations, a result that raises concerns about the potential genotoxic effects of the drug in recipient waters. Copyright © 2017 Elsevier B.V. All rights reserved.

Aspect ratio has no effect on genotoxicity of multi-wall carbon nanotubes.

Science.gov (United States)

Kim, Jin Sik; Lee, Kyu; Lee, Young Hee; Cho, Hyun Sun; Kim, Ki Heon; Choi, Kyung Hee; Lee, Sang Hee; Song, Kyung Seuk; Kang, Chang Soo; Yu, Il Je

2011-07-01

Carbon nanotubes (CNTs) have specific physico-chemical and electrical properties that are useful for telecommunications, medicine, materials, manufacturing processes and the environmental and energy sectors. Yet, despite their many advantages, it is also important to determine whether CNTs may represent a hazard to the environment and human health. Like asbestos, the aspect ratio (length:diameter) and metal components of CNTs are known to have an effect on the toxicity of carbon nanotubes. Thus, to evaluate the toxic potential of CNTs in relation to their aspect ratio and metal contamination, in vivo and in vitro genotoxicity tests were conducted using high-aspect-ratio (diameter: 10-15 nm, length: ~10 μm) and low-aspect-ratio multi-wall carbon nanotubes (MWCNTs, diameter: 10-15 nm, length: ~150 nm) according to OECD test guidelines 471 (bacterial reverse mutation test), 473 (in vitro chromosome aberration test), and 474 (in vivo micronuclei test) with a good laboratory practice system. To determine the treatment concentration for all the tests, a solubility and dispersive test was performed, and a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) solution found to be more suitable than distilled water. Neither the high- nor the low-aspect-ratio MWCNTs induced any genotoxicity in a bacterial reverse mutation test (~1,000 μg/plate), in vitro chromosome aberration test (without S9: ~6.25 μg/ml, with S9: ~50 μg/ml), or in vivo micronuclei test (~50 mg/kg). However, the high-aspect-ratio MWCNTs were found to be more toxic than the low-aspect-ratio MWCNTs. Thus, while high-aspect-ratio MWCNTs do not induce direct genotoxicity or metabolic activation-mediated genotoxicity, genotoxicity could still be induced indirectly through oxidative stress or inflammation.

Mercury-induced genotoxicity in marine diatom (Chaetoceros tenuissimus)

Digital Repository Service at National Institute of Oceanography (India)

Sarker, S.; Desai, S.R.; Verlecar, X.N.; Sarker, M.S.; Sarkar, A.

In this paper, we present an evaluation of genotoxic responses in marine diatom, Chaetoceros tenuissimus, isolated from Kandla Creek (lat 23.03° N, long 70.22° E), Gujarat, India, in terms of impairment of DNA integrity as a function...

Radioprotective effect of exogenic hypoxia in fractionated irradiation

International Nuclear Information System (INIS)

Kazymbetov, P.; Yarmonenko, S.P.; Vajnson, A.A.

1988-01-01

During the experiments with mice it is established, that exogenic hypoxia protective effect (8%O 2 ), evaluated according to survival rate, decreases at the change from single to fractionated irradiation. Dose change factor (DCF) is equal to 1.55 and 1.22-1.31, respectively. Skin protection using exogenic hypoxia at the local fractionated irradiation is expressed more, than at the fractionated one. DCF is equal to 1.56 and 1.28, respectively. Exogenic hypoxia protection effect in the tumor is expressed rather weakly. DCF at single and fractionated irradiation constitutes 1.03 and 1.07-1.13, respectively. Due to skin preferential protection the therapeutic gain factor at irradiation under the exogenic hypoxia conditions constitutes 1.24 and 1.38-1.46, respectively, at single and fractionated irradiation

Seven Deadliest Wireless Technologies Attacks

CERN Document Server

Haines, Brad

2010-01-01

How can an information security professional keep up with all of the hacks, attacks, and exploits? One way to find out what the worst of the worst are is to read the seven books in our Seven Deadliest Attacks Series. Not only do we let you in on the anatomy of these attacks but we also tell you how to get rid of them and how to defend against them in the future. Countermeasures are detailed so that you can fight against similar attacks as they evolve. Attacks featured in this book include:Bluetooth AttacksCredit Card, Access Card, and Passport AttacksBad Encryption

Explaining Cigarette Smoking: An Endogenous-Exogenous Analysis.

Science.gov (United States)

McKillip, Jack

Kruglanski's endogenous-exogenous partition, when applied to reasons given by smokers for smoking cigarettes, distinguishes two types of actions: (1) endogenous reasons implying that the behavior of consuming the cigarette is the goal of the action and the actor is positive toward the behavior, and (2) exogenous reasons implying that the behavior…

Association between Use of Exogenous Testosterone Therapy and Risk of Venous Thrombotic Events among Exogenous Testosterone Treated and Untreated Men with Hypogonadism.

Science.gov (United States)

Li, Hu; Benoit, Karin; Wang, Wei; Motsko, Stephen

2016-04-01

Limited information exists about whether exogenous testosterone therapy is associated with a risk of venous thrombotic events. We investigated via cohort and nested case-control analyses whether exogenous testosterone therapy is associated with the risk of venous thrombotic events in men with hypogonadism. Databases were reviewed to identify men prescribed exogenous testosterone therapy and/or men with a hypogonadism diagnosis. Propensity score 1:1 matching was used to select patients for cohort analysis. Cases (men with venous thrombotic events) were matched 1:4 with controls (men without venous thrombotic events) for the nested case-control analysis. Primary outcome was defined as incident idiopathic venous thrombotic events. Cox regression and conditional logistic regression were used to assess HRs and ORs, respectively. Sensitivity analyses were also performed. A total of 102,650 exogenous testosterone treated and 102,650 untreated patients were included in cohort analysis after matching, and 2,785 cases and 11,119 controls were included in case-control analysis. Cohort analysis revealed a HR of 1.08 for all testosterone treated patients (95% CI 0.91, 1.27, p = 0.378). Case-control analysis resulted in an OR of 1.02 (95% CI 0.92, 1.13, p = 0.702) for current exogenous testosterone therapy exposure and an OR of 0.92 (95% CI 0.82, 1.03, p = 0.145) for past exogenous testosterone therapy exposure. These results remained nonstatistically significant after stratifying by exogenous testosterone therapy administration route and age category. Most sensitivity analyses yielded consistent results. No significant association was found between exogenous testosterone therapy and incidents of idiopathic or overall venous thrombotic events in men with hypogonadism. However, some discrepant findings exist for the association between injectable formulations and the risk of overall venous thrombotic events. Copyright © 2016 American Urological Association Education and Research

[Genotoxic damage among artisanal and small-scale mining workers exposed to mercury].

Science.gov (United States)

Rosales-Rimache, Jaime A; Elizabeth Malca, Nancy; Alarcón, Jhonatan J; Chávez, Manuel; Gonzáles, Marco Antonio

2013-01-01

To determine the genotoxic damage among artisanal and small-scale mining workers exposed to mercury. Observational cross-sectional study which evaluated mercury-exposed workers (n=83), whose cells were collected by mouth swab for further staining, microscopic observance, micronuclei count, and other nuclear alterations. 24-hour urine was also collected for the determination of inorganic mercury. 68.7% of participants were male, the mean age being 43 ± 12,4 years (range: 16-76). The average time of occupational exposure to mercury was 12,1 ± 6,7 years, and the contact with mercury was 4,1 ± 3,6 kg per person per day. 93% of participants failed to wear personal protection gear while handling mercury. Results of biological monitoring showed that 17% of participants had concentrations of mercury in urine higher than 2,5 µg/L, this value being the detection limit of the measurement technique used. Results of the genotoxic evaluation evidenced that 15% of people with labor exposure to mercury presented micronuclei in mouth epithelial cells, and other indicators of nuclear alteration such as nucleoplasmic bridges, gemmation and binucleation were found, which are also considered genotoxic events associated to the exposure of physical or chemical risk agents. The finding of micronuclei in mouth epithelial cells reflects genotoxic damage associated to the labor exposure of mercury used in artisanal and small-scale mining activities.

High Dose Ascorbate Causes Both Genotoxic and Metabolic Stress in Glioma Cells

Science.gov (United States)

Castro, Maria Leticia; Carson, Georgia M.; McConnell, Melanie J.; Herst, Patries M.

2017-01-01

We have previously shown that exposure to high dose ascorbate causes double stranded breaks (DSBs) and a build-up in S-phase in glioblastoma (GBM) cell lines. Here we investigated whether or not this was due to genotoxic stress as well as metabolic stress generated by exposure to high dose ascorbate, radiation, ascorbate plus radiation and H2O2 in established and primary GBM cell lines. Genotoxic stress was measured as phosphorylation of the variant histone protein, H2AX, 8-oxo-7,8-dihydroguanine (8OH-dG) positive cells and cells with comet tails. Metabolic stress was measured as a decrease in NADH flux, mitochondrial membrane potential (by CMXRos), ATP levels (by ATP luminescence) and mitochondrial superoxide production (by mitoSOX). High dose ascorbate, ascorbate plus radiation, and H2O2 treatments induced both genotoxic and metabolic stress. Exposure to high dose ascorbate blocked DNA synthesis in both DNA damaged and undamaged cell of ascorbate sensitive GBM cell lines. H2O2 treatment blocked DNA synthesis in all cell lines with and without DNA damage. DNA synthesis arrest in cells with damaged DNA is likely due to both genotoxic and metabolic stress. However, arrest in DNA synthesis in cells with undamaged DNA is likely due to oxidative damage to components of the mitochondrial energy metabolism pathway. PMID:28737676

Blocking of Brute Force Attack

OpenAIRE

M.Venkata Krishna Reddy

2012-01-01

A common threat Web developers face is a password-guessing attack known as a brute-force attack. A brute-force attack is an attempt to discover a password by systematically trying every possible combination of letters, numbers, and symbols until you discover the one correct combination that works. If your Web site requires user authentication, you are a good target for a brute-force attack. An attacker can always discover a password through a brute-force attack, but the downside is that it co...

P-wave dispersion in endogenous and exogenous subclinical hyperthyroidism.

Science.gov (United States)

Gen, R; Akbay, E; Camsari, A; Ozcan, T

2010-02-01

The aim of this study was to measure maximum P wave duration (Pmax) and P wave dispersion (PWD), which can be indicators for the risk of paroxysmal atrial fibrillation when increased, and to reveal their relationship with thyroid hormone levels in patients with endogenous and exogenous subclinical hyperthyroidism. Seventy-one patients with sublinical thyrotoxicosis (34 endogenous, 37 exogenous) and 69 healthy individuals were enrolled in the study. Pmax and minimum P wave duration (Pmin) on electrocardiogram recordings were measured and PWD was calculated as Pmax-Pmin. Pmax (pendogenous subclinical hyperthyroidism compared with the control group. Pmax (pexogenous subclinical thyrotoxicosis compared with the control group. Pmax (p=0.710) and PWD (p=0.127) were not significantly different in patients with endogenous subclinical hyperthyroidism compared with exogenous subclinical hyperthyroid patients. Pmax and PWD negatively associated with TSH in endogenous and exogenous subclinical hyperthyroidism. In the present study, we observed that Pmax and PWD were longer in patients with endogenous and exogenous subclinical hyperthyroidism. Lack of a difference in Pmax and PWD between patients with endogenous and exogenous subclinical hyperthyroidism seems to support the idea that hormone levels rather than the etiology of thyrotoxicosis affect the heart.

Genotoxic and apoptotic effects of Goeckerman therapy for psoriasis

Energy Technology Data Exchange (ETDEWEB)

Borska, L.; Andrys, C.; Krejsek, J.; Hamakova, K.; Kremlacek, J.; Palicka, V.; Ranna, D.; Fiala, Z. [Charles University Prague, Prague (Czech Republic). Faculty of Medicine

2010-03-15

Goeckerman therapy (GT) for psoriasis is based on cutaneous application of crude coal tar (polycyclic aromatic hydrocarbons (PAH)) and exposure to ultraviolet radiation (UVR). PAH and UVR are mutagenic, carcinogenic and immunotoxic agents that promote apoptosis. We evaluated dermal absorption of PAH as well as the genotoxic and apoptotic effects of GT in 20 patients with psoriasis, by determining numbers of chromosomal abnormalities in peripheral lymphocytes, and levels of 1-hydroxypyrene (1-OHP), p53 protein and soluble FasL (sFasL) in urine and/or blood, before and after GT. Psoriasis Area and Severity Index (PASI) score was used to evaluate clinical efficacy of GT. Compared with pre-treatment levels, there was a significant increase in urine 1-OHP, indicating a high degree of dermal absorption of PAH (P <0.01). We also found a significant increase in the number of chromosomal abnormalities in peripheral blood lymphocytes (P <0.001), suggesting that GT is genotoxic; significantly increased p53 protein in plasma (P <0.05), an indicator of cell response to DNA damage; and significantly increased sFasL in serum (P <0.01), an indicator of apoptosis. The PASI score was significantly decreased after GT (P <0.001), confirming clinical benefit of this treatment. Our results demonstrate high dermal absorption of PAH during GT and provide evidence that GT promotes genotoxicity and apoptosis.

Observations of the effect of atmospheric processes on the genotoxic potency of airborne particulate matter

DEFF Research Database (Denmark)

Feilberg, Anders; Nielsen, Torben; Binderup, Mona-Lise

2002-01-01

In this study, the relationship between genotoxic potency and the occurrence of polycyclic aromatic hydrocarbons (PAH), including benzo(a)pyrene (BaP), and nitro-PAH in urban and semi-rural air masses has been investigated. The Salmonella/microsome assay has been used as a measure of genotoxic po...

In vitro and in vivo genotoxicity of 1,3-butadiene and metabolites.

OpenAIRE

Arce, G T; Vincent, D R; Cunningham, M J; Choy, W N; Sarrif, A M

1990-01-01

1,3-Butadiene and two major genotoxic metabolites 3,4-epoxybutene (EB) and 1,2:3,4-diepoxybutane (DEB) were used as model compounds to determine if genetic toxicity findings in animal and human cells can aid in extrapolating animal toxicity data to man. Sister chromatid exchange (SCE) and micronucleus induction results indicated 1,3-butadiene was genotoxic in the bone marrow of the mouse but not the rat. This paralleled the chronic bioassays which showed mice to be more susceptible than rats ...

Genotoxicity of two heavy metal compounds: lead nitrate and cobalt chloride in Polychaete Perinereis cultrifera.

Science.gov (United States)

Singh, Nisha; Bhagat, Jacky; Ingole, Baban S

2017-07-01

The present study explores the in vivo and in vitro genotoxic effects of lead nitrate, [Pb(NO 3 ) 2 ] a recognized environmental pollutant and cobalt chloride (CoCl 2 ), an emerging environmental pollutant in polychaete Perinereis cultrifera using comet assay. Despite widespread occurrence and extensive industrial applications, no previous published reports on genotoxicity of these compounds are available in polychaete as detected by comet assay. Polychaetes were exposed in vivo to Pb(NO 3 ) 2 (0, 100, 500, and 1000 μg/l) and CoCl 2 (0, 100, 300, and 500 μg/l) for 5 days. At 100 μg/l Pb(NO 3 ) 2 concentration, tail DNA (TDNA) values in coelomocytes were increase by 1.16, 1.43, and 1.55-fold after day 1, day 3, and day 5, whereas, OTM showed 1.12, 2.33, and 2.10-fold increase in in vivo. Pb(NO 3 ) 2 showed a concentration and time-dependent genotoxicity whereas CoCl 2 showed a concentration-dependent genotoxicity in in vivo. A concentration-dependent increase in DNA damage was observed in in vitro studies for Pb(NO 3 ) 2 and CoCl 2 . DNA damage at 500 μg/L showed almost threefold increase in TDNA and approximately fourfold increase in OTM as compared to control in in vitro. Our studies suggest that Pb(NO 3 ) 2 and CoCl 2 have potential to cause genotoxic damage, with Pb(NO 3 ) 2 being more genotoxic in polychaete and should be used more carefully in industrial and other activities. Graphical abstract.

Genotoxicity of indium tin oxide by comet test

Directory of Open Access Journals (Sweden)

İbrahim Hakkı Ciğerci

2015-06-01

Full Text Available Indium tin oxide (ITO is used for liquid crystal display (LCDs, electrochromic displays, flat panel displays, field emission displays, touch or laptop computer screens, cell phones, energy conserving architectural windows, defogging aircraft and automobile windows, heat-reflecting coatings to increase light bulb efficiency, gas sensors, antistatic window coatings, wear resistant layers on glass, nanowires and nanorods because of its unique properties of high electrical conductivity, transparency and mechanical resistance.Genotoxic effects of ITO were investigated on the root cells of Allium cepa by Comet assay. A. cepa roots were treated with the aqueous dispersions of ITO at 5 different concentrations (12.5, 25, 50, 75, and 100 ppm for 4 h. A significant increase in DNA damage was a observed at all concentrations of ITO by Comet assay. These result indicate that ITO exhibit genotoxic activity in A. cepa root meristematic cells.

Solidarity under Attack

DEFF Research Database (Denmark)

Meret, Susi; Goffredo, Sergio

2017-01-01

https://www.opendemocracy.net/can-europe-make-it/susi-meret-sergio-goffredo/solidarity-under-attack......https://www.opendemocracy.net/can-europe-make-it/susi-meret-sergio-goffredo/solidarity-under-attack...

Attack surfaces

DEFF Research Database (Denmark)

Gruschka, Nils; Jensen, Meiko

2010-01-01

The new paradigm of cloud computing poses severe security risks to its adopters. In order to cope with these risks, appropriate taxonomies and classification criteria for attacks on cloud computing are required. In this work-in-progress paper we present one such taxonomy based on the notion...... of attack surfaces of the cloud computing scenario participants....

Metabolic profile and genotoxicity in obese rats exposed to cigarette smoke.

Science.gov (United States)

Damasceno, Debora C; Sinzato, Yuri K; Bueno, Aline; Dallaqua, Bruna; Lima, Paula H; Calderon, Iracema M P; Rudge, Marilza V C; Campos, Kleber E

2013-08-01

Experimental studies have shown that exposure to cigarette smoke has negative effects on lipid metabolism and oxidative stress status. Cigarette smoke exposure in nonpregnant and pregnant rats causes significant genotoxicity (DNA damage). However, no previous studies have directly evaluated the effects of obesity or the association between obesity and cigarette smoke exposure on genotoxicity. Therefore, the aim of the present investigation was to evaluate DNA damage levels, oxidative stress status and lipid profiles in obese Wistar rats exposed to cigarette smoke. Female rats subcutaneously (s.c.) received a monosodium glutamate solution or vehicle (control) during the neonatal period to induce obesity. The rats were randomly distributed into three experimental groups: control, obese exposed to filtered air, and obese exposed to tobacco cigarette smoke. After a 2-month exposure period, the rats were anesthetized and killed to obtain blood samples for genotoxicity, lipid profile, and oxidative stress status analyses. The obese rats exposed to tobacco cigarette smoke presented higher DNA damage, triglycerides, total cholesterol, free fatty acids, VLDL-c, HDL-c, and LDL-c levels compared to control and obese rats exposed to filtered air. Both obese groups showed reduced SOD activity. These results showed that cigarette smoke enhanced the effects of obesity. In conclusion, the association between obesity and cigarette smoke exposure exacerbated the genotoxicity, negatively impacted the biochemical profile and antioxidant defenses and caused early glucose intolerance. Thus, the changes caused by cigarette smoke exposure can trigger the earlier onset of metabolic disorders associated with obesity, such as diabetes and metabolic syndrome. Copyright © 2012 The Obesity Society.

Evaluation of the genotoxicity of cellulose nanofibers.

Science.gov (United States)

de Lima, Renata; Oliveira Feitosa, Leandro; Rodrigues Maruyama, Cintia; Abreu Barga, Mariana; Yamawaki, Patrícia Cristina; Vieira, Isolda Jesus; Teixeira, Eliangela M; Corrêa, Ana Carolina; Caparelli Mattoso, Luiz Henrique; Fernandes Fraceto, Leonardo

2012-01-01

Agricultural products and by products provide the primary materials for a variety of technological applications in diverse industrial sectors. Agro-industrial wastes, such as cotton and curaua fibers, are used to prepare nanofibers for use in thermoplastic films, where they are combined with polymeric matrices, and in biomedical applications such as tissue engineering, amongst other applications. The development of products containing nanofibers offers a promising alternative for the use of agricultural products, adding value to the chains of production. However, the emergence of new nanotechnological products demands that their risks to human health and the environment be evaluated. This has resulted in the creation of the new area of nanotoxicology, which addresses the toxicological aspects of these materials. Contributing to these developments, the present work involved a genotoxicological study of different nanofibers, employing chromosomal aberration and comet assays, as well as cytogenetic and molecular analyses, to obtain preliminary information concerning nanofiber safety. The methodology consisted of exposure of Allium cepa roots, and animal cell cultures (lymphocytes and fibroblasts), to different types of nanofibers. Negative controls, without nanofibers present in the medium, were used for comparison. The nanofibers induced different responses according to the cell type used. In plant cells, the most genotoxic nanofibers were those derived from green, white, and brown cotton, and curaua, while genotoxicity in animal cells was observed using nanofibers from brown cotton and curaua. An important finding was that ruby cotton nanofibers did not cause any significant DNA breaks in the cell types employed. This work demonstrates the feasibility of determining the genotoxic potential of nanofibers derived from plant cellulose to obtain information vital both for the future usage of these materials in agribusiness and for an understanding of their environmental

Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities

International Nuclear Information System (INIS)

Klumpp, Andreas; Ansel, Wolfgang; Klumpp, Gabriele; Calatayud, Vicent; Garrec, Jean Pierre; He Shang; Penuelas, Josep; Ribas, Angela; Ro-Poulsen, Helge; Rasmussen, Stine; Sanz, Maria Jose; Vergne, Phillippe

2006-01-01

Urban atmospheres contain complex mixtures of air pollutants including mutagenic and carcinogenic substances such as benzene, diesel soot, heavy metals and polycyclic aromatic hydrocarbons. In the frame of a European network for the assessment of air quality by the use of bioindicator plants, the Tradescantia micronucleus (Trad-MCN) test was applied to examine the genotoxicity of urban air pollution. Cuttings of Tradescantia clone no. 4430 were exposed to ambient air at 65 monitoring sites in 10 conurbations employing a standardised methodology. The tests revealed an elevated genotoxic potential mainly at those urban sites which were exposed to severe car traffic emissions. This bioassay proved to be a suitable tool to detect local 'hot spots' of mutagenic air pollution in urban areas. For its use in routine monitoring programmes, however, further standardisation of cultivation and exposure techniques is recommended in order to reduce the variability of results due to varying environmental conditions. - The Tradescantia micronucleus test can be used to assess genotoxic potential at urban sites

Genotoxic effects of N-nitrosodimethylamine in somatic and generative cells of mice

Directory of Open Access Journals (Sweden)

Anna V. Lovinskaya

2017-10-01

Full Text Available N-Nitrosodimethylamine (NDMA was shown to have genotoxic properties in acute and subacute studies on laboratory mice. The organ-specificity of the genotoxic effect of NDMA was revealed using the Comet assay. The most sensitive organs to the action of NDMA were kidneys and liver. DNA damage in liver cells of NDMA-treated animals at doses of 4.0 and 8.0 mg/kg, increased compared to control in 6.9 and 12.5 (р < 0.001, and in kidney cells – in 8.1 and 14.2 times (р < 0.001, respectively. NDMA also showed genotoxic activity in the reproductive cells of experimental animals, causing structural disorders of synaptonemal complexes in spermatocyte. In NDMA-treated animals at a dose of 2.0 mg/kg in acute and subacute studies, the level of spermatocytes with damaged synaptonemal complexes increased statistically significantly compared to control in 6.0 and 7.0 (р < 0.05 times, respectively.

Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities

Energy Technology Data Exchange (ETDEWEB)

Klumpp, Andreas [Institute for Landscape and Plant Ecology (320), University of Hohenheim, 70593 Stuttgart (Germany)]. E-mail: aklumpp@uni-hohenheim.de; Ansel, Wolfgang [Institute for Landscape and Plant Ecology (320), University of Hohenheim, 70593 Stuttgart (Germany); Klumpp, Gabriele [Institute for Landscape and Plant Ecology (320), University of Hohenheim, 70593 Stuttgart (Germany); Calatayud, Vicent [Fundacion CEAM, Parque Tecnologico, c/Charles Darwin 14, 46980 Paterna, Valencia (Spain); Garrec, Jean Pierre [INRA Nancy, Laboratoire Pollution Atmospherique, 54280 Champenoux (France); He Shang [INRA Nancy, Laboratoire Pollution Atmospherique, 54280 Champenoux (France); Penuelas, Josep [Unitat Ecofisiologia CSIC-CEAB-CREAF, Universitat Autonoma de Barcelona, Ed. C, 08193 Bellaterra, Barcelona (Spain); Ribas, Angela [Unitat Ecofisiologia CSIC-CEAB-CREAF, Universitat Autonoma de Barcelona, Ed. C, 08193 Bellaterra, Barcelona (Spain); Ro-Poulsen, Helge [Botanical Institute, University of Copenhagen, Oster Farimagsgade 2D, 1353 Copenhagen K (Denmark); Rasmussen, Stine [Botanical Institute, University of Copenhagen, Oster Farimagsgade 2D, 1353 Copenhagen K (Denmark); Sanz, Maria Jose [Fundacion CEAM, Parque Tecnologico, c/Charles Darwin 14, 46980 Paterna, Valencia (Spain); Vergne, Phillippe [ENS Lyon and Lyon Botanical Garden, 46 Allee d' Italie, 69364 Lyon Cedex 07 (France)

2006-02-15

Urban atmospheres contain complex mixtures of air pollutants including mutagenic and carcinogenic substances such as benzene, diesel soot, heavy metals and polycyclic aromatic hydrocarbons. In the frame of a European network for the assessment of air quality by the use of bioindicator plants, the Tradescantia micronucleus (Trad-MCN) test was applied to examine the genotoxicity of urban air pollution. Cuttings of Tradescantia clone no. 4430 were exposed to ambient air at 65 monitoring sites in 10 conurbations employing a standardised methodology. The tests revealed an elevated genotoxic potential mainly at those urban sites which were exposed to severe car traffic emissions. This bioassay proved to be a suitable tool to detect local 'hot spots' of mutagenic air pollution in urban areas. For its use in routine monitoring programmes, however, further standardisation of cultivation and exposure techniques is recommended in order to reduce the variability of results due to varying environmental conditions. - The Tradescantia micronucleus test can be used to assess genotoxic potential at urban sites.

In Vitro Genotoxic Effects of Four Helichrysum Species in Human Lymphocytes Cultures

Directory of Open Access Journals (Sweden)

Erhan H Erolu

2010-01-01

Full Text Available Helichrysum sanguineum, Helichrysum pamphylicum, Helichrysum orientale, Helichrysum noeanum (Asteraceae are medicinal plants. For centuries, they have been used as tea in Turkey because of their medicinal properties. So far no scientifc evidence has been found in a literature survey regarding the genotoxic effects of these plants. This work evaluated the genotoxic effects on human lymphocyte cultures induced by methanol extracts of these plants, assayed in different concentrations (0.01, 0.05, 0.1, 0.5 and 1 mg/mL. According to the results, Helichrysum noeanum, Helichrysum pamphylicum and Helichrysum sanguineum induced the formation of micronuclei and decreased the mitotic and replication indexes. Helichrysum orientale did not affect these parameters, whereas Helichrysum noeanum, Helichrysum pamphylicum and Helichrysum sanguineum were clearly genotoxic. They should therefore not be used freely in alternative medicine, although their antiproliferative activity may suggest antimitotic and anticarcinogenic properties. Helichrysum orientale could be used in alternative medicine.

Acute Toxicity and Genotoxic Activity of Avocado Seed Extract (Persea americana Mill., c.v. Hass

Directory of Open Access Journals (Sweden)

Eduardo Padilla-Camberos

2013-01-01

Full Text Available The use of vegetal extracts requires toxicological and genotoxic evaluations to establish and verify safety before being added to human cosmetic, pharmaceutical medicine, or alimentary products. Persea americana seeds have been used in traditional medicine as treatment for several diseases. In this work, the ethanolic seed extract of Persea americana was evaluated with respect to its genotoxic potential through micronucleus assay in rodents. The frequency of micronuclei in groups of animals treated with avocado seed extract showed no differences compared to the negative control (vehicle; therefore, it is considered that the avocado seed extract showed no genotoxic activity in the micronucleus test.

Genotoxicity studies on DNA-interactive telomerase inhibitors with application as anti-cancer agents.

Science.gov (United States)

Harrington, Dean J; Cemeli, Eduardo; Carder, Joanna; Fearnley, Jamie; Estdale, Sian; Perry, Philip J; Jenkins, Terence C; Anderson, Diana

2003-01-01

Telomerase-targeted strategies have aroused recent interest in anti-cancer chemotherapy, because DNA-binding drugs can interact with high-order tetraplex rather than double-stranded (duplex) DNA targets in tumour cells. However, the protracted cell-drug exposure times necessary for clinical application require that telomerase inhibitory efficacy must be accompanied by both low inherent cytotoxicity and the absence of mutagenicity/genotoxicity. For the first time, the genotoxicity of a number of structurally diverse DNA-interactive telomerase inhibitors is examined in the Ames test using six Salmonella typhimurium bacterial strains (TA1535, TA1537, TA1538, TA98, TA100, and TA102). DNA damage induced by each agent was also assessed using the Comet assay with human lymphocytes. The two assay procedures revealed markedly different genotoxicity profiles that are likely to reflect differences in metabolism and/or DNA repair between bacterial and mammalian cells. The mutational spectrum for a biologically active fluorenone derivative, shown to be mutagenic in the TA100 strain, was characterised using a novel and rapid assay method based upon PCR amplification of a fragment of the hisG46 allele, followed by RFLP analysis. Preliminary analysis indicates that the majority (84%) of mutations induced by this compound are C --> A transversions at position 2 of the missense proline codon of the hisG46 allele. However, despite its genotoxic bacterial profile, this fluorenone agent gave a negative response in the Comet assay, and demonstrates how unwanted systemic effects (e.g., cytotoxicity and genotoxicity) can be prevented or ameliorated through suitable molecular fine-tuning of a candidate drug in targeted human tumour cells. Copyright 2003 Wiley-Liss, Inc.

Comparative potency approach based on H2AX assay for estimating the genotoxicity of polycyclic aromatic hydrocarbons.

Science.gov (United States)

Audebert, M; Zeman, F; Beaudoin, R; Péry, A; Cravedi, J-P

2012-04-01

Polycyclic Aromatic Hydrocarbons (PAHs) constitute a family of over one hundred compounds and can generally be found in complex mixtures. PAHs metabolites cause DNA damage which can lead to the development of carcinogenesis. Toxicity assessment of PAH complex mixtures is currently expressed in terms of toxic equivalents, based on Toxicity Equivalent Factors (TEFs). However, the definition of new TEFs for a large number of PAH could overcome some limitations of the current method and improve cancer risk assessment. The current investigation aimed at deriving the relative potency factors of PAHs, based on their genotoxic effect measured in vitro and analyzed with mathematical models. For this purpose, we used a new genotoxic assay (γH2AX) with two human cell lines (HepG2 and LS-174T) to analyze the genotoxic properties of 13 selected PAHs at low doses after 24h treatment. The dose-response for genotoxic effects was modeled with a Hill model; equivalency between PAHs at low dose was assessed by applying constraints to the model parameters. In the two cell lines tested, we observed a clear dose-response for genotoxic effects for 11 tested compounds. LS-174T was on average ten times more sensitive than HepG2 towards PAHs regarding genotoxicity. We developed new TEFs, which we named Genotoxic Equivalent Factor (GEF). Calculated GEF for the tested PAHs were generally higher than the TEF usually used. Our study proposed a new in vitro based method for the establishment of relevant TEFs for PAHs to improve cancer risk assessment. Copyright © 2012 Elsevier Inc. All rights reserved.

Evaluation of genotoxic potential of neurotoxin anatoxin-a with the use of umuC test.

Science.gov (United States)

Sieroslawska, Anna; Rymuszka, Anna

2010-01-01

The aim of this study was to evaluate genotoxicity of anatoxin-a, cyanotoxin of neurotoxic activity. Additionally, other frequently detected cyanotoxin of previously described genotoxic potential, microcystin-LR, was used at the same concentrations, as well as the mixture of both toxins, anatoxin-a and microcystin-LR. Genotoxicity of the toxins was determined with the use of the umuC assay, in which the induction and expression of the umuC - lacZ reporter gene was assessed. The test was conducted on Salmonella typhimurium TA 1535/pSK1002 strain, with and without metabolic transformation. The toxin concentrations were 0.25, 0.5, 1 and 2 µg/ml. The exposure time was 2 h. The highest inefficient concentration of anatoxin-a without metabolic transformation was 0.25 µg/ml, of microcystin-LR was 0.5 µg/ml and in case of the toxin mixture all used concentrations induced the umuC gene. When S9 fraction was added to the samples, no effects were detected. To our knowledge, this is the first report on genotoxic effects of anatoxin-a. Although the study is preliminary and needs further research, however, indicates the new potential activity of the toxin, as well as the possible increase of genotoxicity of other cyanotoxins, more stable in the environment, e.g. microcystin-LR.

Initial hazard screening for genotoxicity of photo-transformation products of ciprofloxacin by applying a combination of experimental and in-silico testing

International Nuclear Information System (INIS)

Toolaram, Anju Priya; Haddad, Tarek; Leder, Christoph; Kümmerer, Klaus

2016-01-01

Ciprofloxacin (CIP) is a broad-spectrum antibiotic found within μg/L concentration range in the aquatic environment. It is a known contributor of umuC induction in hospital wastewater samples. CIP can undergo photolysis to result in many transformation products (TPs) of mostly unknown toxicity. The aims of this study were to determine the genotoxicity of the UV mixtures and to understand the possible genotoxic role of the stable TPs. As such, CIP and its UV-irradiated mixtures were investigated in a battery of genotoxicity and cytotoxicity in vitro assays. The combination index (CI) analysis of residual CIP in the irradiated mixtures was performed for the umu assay. Further, Quantitative Structure–Activity Relationships (QSARs) predicted selected genotoxicity endpoints of the identified TPs. CIP achieved primary elimination after 128 min of irradiation but was not completely mineralized. Nine photo-TPs were identified. The irradiated mixtures were neither mutagenic in the Ames test nor genotoxic in the in vitro micronucleus (MN) test. Like CIP, the irradiated mixtures were umuC inducing. The CI analysis revealed that the irradiated mixtures and the corresponding CIP concentration in the mixtures shared similar umuC potentials. QSAR predictions suggested that the TPs may be capable of inducing chromosome aberration, MN in vivo, bacterial mutation and mammalian mutation. However, the experimental testing for a few genotoxic endpoints did not show significant genotoxic activity for the TPs present as a component of the whole mixture analysis and therefore, further genotoxic endpoints may need to be investigated to fully confirm this. - Highlights: • Identified photo-transformation products (TPs) retained the quinolone core. • Experimental and in silico tools assessed for genotoxicity of TPs in the mixtures. • Some of the TPs were predicted as genotoxic by QSAR analysis. • Irradiated mixtures were neither micronuclei inducing nor mutagenic in Ames test

Seven Deadliest Microsoft Attacks

CERN Document Server

Kraus, Rob; Borkin, Mike; Alpern, Naomi

2010-01-01

Do you need to keep up with the latest hacks, attacks, and exploits effecting Microsoft products? Then you need Seven Deadliest Microsoft Attacks. This book pinpoints the most dangerous hacks and exploits specific to Microsoft applications, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Windows Operating System-Password AttacksActive Directory-Escalat

Ecotoxicity and genotoxicity assessment of cytostatic pharmaceuticals

Czech Academy of Sciences Publication Activity Database

Zounková, R.; Odráška, P.; Doležalová, L.; Hilscherová, Klára; Maršálek, Blahoslav; Bláha, Luděk

2007-01-01

Roč. 26, č. 10 (2007), s. 2208-2214 ISSN 0730-7268 Grant - others:GA MŠk(CZ) 2B06171; ECODIS(XE) 518043-1 Institutional research plan: CEZ:AV0Z60050516 Source of funding: R - rámcový projekt EK Keywords : cytostatic pharmaceuticals * genotoxicity * antineoplastics Subject RIV: EF - Botanics Impact factor: 2.309, year: 2007

Genoprotective and Genotoxic Effects of Thymoquinone on ...

African Journals Online (AJOL)

Comet assays and apoptotic cell studies were performed to evaluate the effect of TQ on the cytotoxicity and genotoxicity-induced by DXR. Results: TQ treatment, alone, (5.0, 10, or 20 µM) increased DNA damage index (DI) in a concentrationdependent manner (0.64 ± 0.09, 0.84 ± 0.07, and 0.93 ± 0.06, respectively).

Endogenous vs. exogenous regulations in the commons

DEFF Research Database (Denmark)

Abatayo, Anna Lou; Lynham, John

2016-01-01

It is widely believed that there is strong experimental evidence to support the idea that exogenously imposed regulations crowd out the intrinsic motivations of common pool resource (CPR) users to refrain from over-harvesting. We introduce a novel experimental design that attempts to disentangle...... potential confounds in previous experiments. A key feature of our experimental design is to have the exact same regulations chosen endogenously as those that are imposed exogenously. When we compare the same regulations chosen endogenously to those externally imposed, we observe no differences in extraction...... endogenous regulations with communication and exogenous regulations without communication. Our results suggest that externally imposed regulations do not crowd out intrinsic motivations in the lab and they confirm that communication facilitates cooperation to reduce extraction....

In vitro evaluation of mutagenicity and genotoxicity of sitagliptin ...

African Journals Online (AJOL)

Keywords: Sitagliptin, Artificial sweeteners, Comet assay, DNA damage, Ames assay, Genotoxicity,. Mutagenicity. Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), Scopus,. International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, EBSCO, African.

Interplay between endogenous and exogenous fluctuations in financial markets

OpenAIRE

Gontis, Vygintas

2016-01-01

We address microscopic, agent based, and macroscopic, stochastic, modeling of the financial markets combining it with the exogenous noise. The interplay between the endogenous dynamics of agents and the exogenous noise is the primary mechanism responsible for the observed long-range dependence and statistical properties of high volatility return intervals. By exogenous noise we mean information flow or/and order flow fluctuations. Numerical results based on the proposed model reveal that the ...

In vivo genotoxicity evaluation of an artichoke (Cynara scolymus L.) aqueous extract.

Science.gov (United States)

Zan, Meriele A; Ferraz, Alexandre B F; Richter, Marc F; Picada, Jaqueline N; de Andrade, Heloisa H R; Lehmann, Mauricio; Dihl, Rafael R; Nunes, Emilene; Semedo, Juliane; Da Silva, Juliana

2013-02-01

The Cynara scolymus (artichoke) is widely consumed as tea or food and shows important therapeutic properties. However, few studies have assessed the possible toxic effects of artichoke extracts. This study evaluates genotoxic and mutagenic activities of artichoke leaf aqueous extract in mice using the comet assay and the micronucleus test. Leaf extracts were given by gavage (500 mg/kg, 1000 mg/kg, and 2000 mg/kg) for 3 consecutive days. Extract composition was investigated using phytochemical screening and high-performance liquid chromatography (HPLC). In addition, antioxidant capacity was analyzed through the diphenyl-picrylhydrazyl (DPPH) and xanthine oxidase assay. Phytochemical screening detected the presence of phenolic compounds, flavonoids, and saponins. HPLC analyses indicated the presence of chlorogenic acid, caffeic acid, isoquercetrin, and rutin. Extracts showed a dose-dependent free radical scavenging effect of DPPH and an inhibitory effect of xanthine oxidase. The genotoxic results showed that leaf extracts did not increase micronuclei in peripheral blood cells. Compared to the control group, a significant increase in comet assay values was observed only in bone marrow of group treated with 2000 mg/kg, the highest dose tested, indicating that artichoke tea should be consumed with moderation. This is the first report of in vivo mutagenic and genotoxic evaluation with C. scolymus. The present study revealed leaf aqueous extract from artichoke shows lack of mutagenicity in vivo, and low genotoxicity and antioxidant activity; indicating that artichoke tea should be consumed with moderation. © 2013 Institute of Food Technologists®

Exogenous reinfection of tuberculosis in a low-burden area.

Science.gov (United States)

Schiroli, Consuelo; Carugati, Manuela; Zanini, Fabio; Bandera, Alessandra; Di Nardo Stuppino, Silvia; Monge, Elisa; Morosi, Manuela; Gori, Andrea; Matteelli, Alberto; Codecasa, Luigi; Franzetti, Fabio

2015-12-01

Recurrence of tuberculosis (TB) can be the consequence of relapse or exogenous reinfection. The study aimed to assess the factors associated with exogenous TB reinfection. Prospective cohort study based on the TB database, maintained at the Division of Infectious Diseases, Luigi Sacco Hospital (Milan, Italy). Time period: 1995-2010. (1) ≥2 episodes of culture-confirmed TB; (2) cure of the first episode of TB; (3) availability of one Mycobacterium tuberculosis isolate for each episode. Genotyping of the M. tuberculosis strains to differentiate relapse and exogenous reinfection. Logistic regression analysis was used to assess the influence of risk factors on exogenous reinfections. Of the 4682 patients with TB, 83 were included. Of these, exogenous reinfection was diagnosed in 19 (23 %). It was independently associated with absence of multidrug resistance at the first episode [0, 10 (0.01-0.95), p = 0.045] and with prolonged interval between the first TB episode and its recurrence [7.38 (1.92-28.32) p = 0.004]. However, TB relapses occurred until 4 years after the first episode. The risk associated with being foreign born, extrapulmonary site of TB, and HIV infection was not statistically significant. In the relapse and re-infection cohort, one-third of the patients showed a worsened drug resistance profile during the recurrent TB episode. Exogenous TB reinfections have been documented in low endemic areas, such as Italy. A causal association with HIV infection could not be confirmed. Relapses and exogenous reinfections shared an augmented risk of multidrug resistance development, frequently requiring the use of second-line anti-TB regimens.

Oxcarbazepine-induced cytotoxicity and genotoxicity in human lymphocyte cultures with or without metabolic activation.

Science.gov (United States)

Atlı Şekeroğlu, Zülal; Kefelioğlu, Haluk; Kontaş Yedier, Seval; Şekeroğlu, Vedat; Delmecioğlu, Berrin

2017-03-01

There has been considerable debate about the relationship between epilepsy and cancer. Oxcarbazepine (OXC) is used for treating certain types of seizures in patients with epilepsy. There have been no detailed investigations about genotoxicity of OXC and its metabolites. Therefore, the aim of this study is to investigate the cytotoxic and genotoxic effects of OXC and its metabolites on cultured human lymphocytes. The cytotoxicity and genotoxicity of OXC on human peripheral blood lymphocytes were examined in vitro by sister chromatid exchange (SCE), chromosomal aberration (CA) and micronucleus (MN) tests. Cultures were treated with 125, 250 and 500 μg/ml of OXC in the presence (3 h treatment) and absence (24 h and 48 h treatment) of a metabolic activator (S9 mix). Dimethyl sulfoxide (DMSO) was used as a solvent control. OXC showed cytotoxic activities due to significant decreases in mitotic index (MI), proliferation index (PI) and nuclear division index (NDI) in the absence of S9 mix when compared with solvent control. Metabolites of OXC also significantly reduced MI and PI in cultures with S9 mix. OXC significantly increased the CAs, aberrant cells, SCE and MN values in the presence and absence of S9 mix. Our results indicated that both OXC and its metabolites have cytotoxic, cytostatic and genotoxic potential on human peripheral blood lymphocyte cultures under the experimental conditions. Further studies are necessary to elucidate the relationship between cytotoxic, cytostatic and genotoxic effects, and to make a possible risk assessment in patients receiving therapy with this drug.

Genotoxicity assessment of magnetic iron oxide nanoparticles with different particle sizes and surface coatings

International Nuclear Information System (INIS)

Liu, Yanping; Xia, Qiyue; Liu, Ying; Zhang, Shuyang; Cheng, Feng; Wang, Li; Li, Hongxia; Xiao, Kai; Zhong, Zhihui

2014-01-01

Magnetic iron oxide nanoparticles (IONPs) have been widely used for various biomedical applications such as magnetic resonance imaging and drug delivery. However, their potential toxic effects, including genotoxicity, need to be thoroughly understood. In the present study, the genotoxicity of IONPs with different particle sizes (10, 30 nm) and surface coatings (PEG, PEI) were assessed using three standard genotoxicity assays, the Salmonella typhimurium reverse mutation assay (Ames test), the in vitro mammalian chromosome aberration test, and the in vivo micronucleus assay. In the Ames test, SMG-10 (PEG coating, 10 nm) showed a positive mutagenic response in all the five test bacterial strains with and without metabolic activation, whereas SEI-10 (PEI coating, 10 nm) showed no mutagenesis in all tester strains regardless of metabolic activation. SMG-30 (PEG coating, 30 nm) was not mutagenic in the absence of metabolic activation, and became mutagenic in the presence of metabolic activation. In the chromosomal aberration test, no increase in the incidence of chromosomal aberrations was observed for all three IONPs. In the in vivo micronucleus test, there was no evidence of increased micronuclei frequencies for all three IONPs, indicating that they were not clastogenic in vivo. Taken together, our results demonstrated that IONPs with PEG coating exhibited mutagenic activity without chromosomal and clastogenic abnormalities, and smaller IONPs (SMG-10) had stronger mutagenic potential than larger ones (SMG-30); whereas, IONPs with SEI coating (SEI-10) were not genotoxic in all three standard genotoxicity assays. This suggests that the mutagenicity of IONPs depends on their particle size and surface coating. (paper)

Histopathological and genotoxic effects of chlorpyrifos in rats.

Science.gov (United States)

Ezzi, Lobna; Belhadj Salah, Imen; Haouas, Zohra; Sakly, Amina; Grissa, Intissar; Chakroun, Sana; Kerkeni, Emna; Hassine, Mohsen; Mehdi, Meriem; Ben Cheikh, Hassen

2016-03-01

This study aims to investigate the effects of chlorpyrifos's sub-acute exposure on male rats. Two groups with six animals each were orally treated, respectively, with 3.1 mg/kg b w and 6.2 mg/kg b w of chlorpyrifos during 4 weeks. The genotoxic effect of chlopyrifos was investigated using the comet assay and the micronucleus test. Some hematological and liver's histopathological changes were also evaluated. Results revealed that chlorpyrifos induced histopathological alterations in liver parenchyma. The lymphoid infiltration observed in liver sections and the increase in white blood cells parameter are signs of inflammation. A significant increase in the platelet' count and in polychromatic erythrocytes/normochromatic erythrocytes (PCE/NCE) ratio was observed in chlorpyrifos-treated groups which could be due to the stimulatory effect of chlorpyrifos on cell formation in the bone marrow at lower doses. In addition, the increase of bone marrow micronucleus percentage and the comet tail length revealed a genotoxic potential of chlorpyrifos in vivo.

Biomonitoring of genotoxic exposure among stainless steel welders

DEFF Research Database (Denmark)

Knudsen, Lisbeth E.; Boisen, T; Christensen, J M

1992-01-01

A biosurvey in the Danish metal industry measured the genotoxic exposure from stainless steel welding. The study comprised measurements of chromosomal aberrations (CA), sister-chromatid exchanges (SCE), unscheduled DNA synthesis (UDS) in peripheral lymphocytes and serum immunoglobulin G. Environm......A biosurvey in the Danish metal industry measured the genotoxic exposure from stainless steel welding. The study comprised measurements of chromosomal aberrations (CA), sister-chromatid exchanges (SCE), unscheduled DNA synthesis (UDS) in peripheral lymphocytes and serum immunoglobulin G....... A higher frequency of chromosomal aberrations, classified as translocations, double minutes, exchanges and rings, was observed in stainless steel welders than in non-welders. SCE was lower in welders working with both MMA and TIG welding than in reference persons. N-Acetoxy-N-acetylaminofluorene (NA...... lymphocytes in exposed persons compared with non-exposed are suggested. MMA welding gave the highest exposure to chromium, an increased number of chromosomal aberrations and a decrease in SCE when compared with TIG welding. Consequently improvements in the occupational practice of stainless steel welding...

Whispering through DDoS attack

OpenAIRE

Miralem Mehic; Jiri Slachta; Miroslav Voznak

2016-01-01

Denial of service (DoS) attack is an attempt of the attacker to disable victim's machine by depleting network or computing resources. If this attack is performed with more than one machine, it is called distributed denial of service (DDoS) attack. Covert channels are those channels which are used for information transmission even though they are neither designed nor intended to transfer information at all. In this article, we investigated the possibility of using of DDoS attack for purposes o...

Genotoxic and teratogenic potential of marine sediment extracts investigated with comet assay and zebrafish test

International Nuclear Information System (INIS)

Kammann, Ulrike; Biselli, Scarlett; Huehnerfuss, Heinrich; Reineke, Ninja; Theobald, Norbert; Vobach, Michael; Wosniok, Werner

2004-01-01

Organic extracts of marine sediments from the North Sea and the Baltic Sea were investigated with two toxicity assays. The comet assay based on the fish cell line Epithelioma papulosum cyprini (EPC) was applied to determine the genotoxic potential; zebrafish embryos (Danio rerio) were used to quantify the teratogenic potential of the samples. EC 50 values were calculated from dose-response curves for both test systems. Highest teratogenic and genotoxic effects normalised to total organic carbon (TOC) content were detected in sediment samples of different origins. Polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) are not likely to be the causes of the observed effects, as demonstrated by a two-step fractionation procedure of selected extracts. The toxic potential was more pronounced in fractions having polarity higher than those possessed by PAHs and PCBs. The suitability of the two in vitro test systems for assessing genotoxic and teratogenic effects of marine sediment extracts could be demonstrated. - Capsule: In vitro toxicity assays are used to assess genotoxic and teratogenic effects of environmental extracts

Investigation of genotoxic potential of various sizes Fe2O3 nanoparticles with comet assay

Directory of Open Access Journals (Sweden)

İbrahim Hakkı Ciğerci

2015-06-01

In this study, genotoxic potential of <50 nm and <100 nm Fe2O3 nanoparticles were investigated by using Comet Assay. Allium cepa root meristems were exposed with five doses (0.001, 0.01, 0.1, 1, 10 mM of <50 nm for 4 hour and three doses (2.5, 5 (EC50, 10 mM for <100 nm of Fe2O3 nanoparticle for 24 and 96 h. Methyl methanesulfonate -MMS (10 ppm was used as a positive control. The results were also analyzed statistically by using SPSS by Windows, 18.0. It was determined that different doses of <50 nm Fe2O3 nanoparticle have no genotoxic effect of DNA. Different doses of <100 nm Fe2O3 have no genotoxic but only 10 mM dose have genotoxic effect on DNA. When compared <50 nm with <100 nm of Fe2O3 nanoparticle; <50 nm have more effects than <100 nm of Fe2O3 on DNA damage.

Characteristics of exogenous carbon monoxide deliveries

Directory of Open Access Journals (Sweden)

Hui-jun Hu

2016-01-01

Full Text Available Carbon monoxide (CO has long been considered an environmental pollutant and a poison. Exogenous exposure to amounts of CO beyond the physiologic level of the body can result in a protective or adaptive response. However, as a gasotransmitter, endogenous CO is important for multiple physiologic functions. To date, at least seven distinct methods of delivering CO have been utilized in animal and clinical studies. In this mini-review, we summarize the exogenous CO delivery methods and compare their advantages and disadvantages.

Moesin Is a Biomarker for the Assessment of Genotoxic Carcinogens in Mouse Lymphoma

Science.gov (United States)

Lee, Yoen Jung; Choi, In-Kwon; Sheen, Yhun Yhong; Park, Sue Nie; Kwon, Ho Jeong

2012-01-01

1,2-Dibromoethane and glycidol are well known genotoxic carcinogens, which have been widely used in industry. To identify a specific biomarker for these carcinogens in cells, the cellular proteome of L5178Y mouse lymphoma cells treated with these compounds was analyzed by 2-dimensional gel electrophoresis (2-DE) and MALDI-TOF mass spectrometry (MS). Of 50 protein spots showing a greater than 1.5-fold increase or decrease in intensity compared to control cells on a 2-D gel, we focused on the candidate biomarker moesin. Western analysis using monoclonal rabbit anti-moesin confirmed the identity of the protein and its increased level of expression upon exposure to the carcinogenic compounds. Moesin expression also increased in cells treated with six additional genotoxic carcinogens, verifying that moesin could serve as a biomarker to monitor phenotypic change upon exposure to genotoxic carcinogens in L5178Y mouse lymphoma cells. PMID:22358511

Use of the Microscreen phage-induction assay to assess the genotoxicity of 14 hazardous industrial wastes

Energy Technology Data Exchange (ETDEWEB)

Houk, V.S.; DeMarini, D.M.

1988-01-01

The Microscreen phage-induction assay, which quantitatively measures the induction of prophage lambda in Escherichia coli WP2s lambda, was used to test 14 crude (unfractionated) hazardous industrial-waste samples for genotoxic activity in the presence and absence of metabolic activation. Eleven of the 14 wastes induced prophage, and induction was observed at concentrations as low as 0.4 picograms per ml. Comparisons between the mutagenicity of these waste samples in Salmonella and their ability to induce prophage lambda indicate that the Microscreen phage-induction assay detected genotoxic activity in all but one of the wastes that were mutagenic in Salmonella. Moreover, the Microscreen assay detected as genotoxic 5 additional wastes that were not detected in the Salmonella assay. The applicability of the Microscreen phage-induction assay for screening hazardous wastes for genotoxic activity is discussed along with some of the problems associated with screening highly toxic wastes containing toxic volatile compounds.

Use of the microscreen phage-induction assay to assess the genotoxicity of 14 hazardous industrial wastes

Energy Technology Data Exchange (ETDEWEB)

Houk, V.S.; DeMarini, D.M.

1988-01-01

The Microscreen phage-induction assay, which quantitatively measures the induction of prophage lambda in Escherichia coli WP2s(lambda), was used to test 14 crude (unfractionated) hazardous industrial waste samples for genotoxic activity in the presence and absence of metabolic activation. Eleven of the 14 wastes induced prophage, and induction was observed at concentrations as low as 0.4 pg per ml. Comparisons between the ability of these waste samples to induce prophage and their mutagenicity in the Salmonella reverse mutation assay indicate that the phage-induction assay detected genotoxic activity in all but one of the wastes that were mutagenic in Salmonella. Moreover, the Microscreen assay detected as genotoxic five additional wastes that were not detected in the Salmonella assay. The applicability of the Microscreen phage-induction assay for screening hazardous wastes for genotoxic activity is discussed, as are some of the problems associated with screening highly toxic wastes containing toxic volatile compounds.

The influence of abiotic factors present in the Rio de la Plata over the chromium genotoxicity

International Nuclear Information System (INIS)

Lopez, L.C.; Moretton, J.

1997-01-01

The alterations suffered by the well-known environmental genotoxic agent, Cr(V I), were studied. Cr(V I) salts were dissolved in water effluent river receptors waters such as from the Rio de la Plata. The influence of abiotic factors present in this kind of water was evaluated using the Rec. assay in Bacillus subtilis. The results detected a soluble fraction that potentiated Cr(V I) genotoxicity. This substance (or group of substances) is sensible to sterilization by heat and UV radiation, and its activity seems to decrease with particulate matter. Its genotoxicity was not affected by high concentrations of particulate matter in the Rio de la Plata water. In samples where chromium salts were added to raw river water, abiotic interference due to sterilization process occurred. A decrease in genotoxicity was found after filtration through inorganic filters (0.22 μ m) and an increase was noticed after exposure to UV radiation. (Author)

Assessment of the in vitro and in vivo genotoxicity of extracts and indole monoterpene alkaloid from the roots of Galianthe thalictroides (Rubiaceae).

Science.gov (United States)

Fernandes, L M; Garcez, W S; Mantovani, M S; Figueiredo, P O; Fernandes, C A; Garcez, F R; Guterres, Z R

2013-09-01

Roots of Galianthe thalictroides K. Schum. (Rubiaceae) are used in folk medicine in the State of Mato Grosso do Sul, Brazil, for treating and preventing cancer. To gain information about the genotoxicity of extracts (aqueous and EtOH), the CHCl₃ phase resulting from partition of the EtOH extract and the indole monoterpene alkaloid 1 obtained from this plant. The genotoxicity of 1 and extracts was evaluated in vivo through the Drosophila melanogaster wing Somatic Mutation and Recombination Test - SMART, while in vitro cytotoxic (MTT) and Comet assays were performed only with alkaloid 1. The results obtained with the SMART test indicated that the aqueous extract had no genotoxic activity. The EtOH extract was not genotoxic to ST descendants but genotoxic to HB ones. The CHCl₃ phase was genotoxic and cytotoxic. Alkaloid 1 showed significant mutational events with SMART, in the cytotoxicity assay (MTT), it showed a high cytotoxicity for human hepatoma cells (HepG2), whereas for the Comet assay, not showing genotoxic activity. The ethanol extract was shown to be genotoxic to HB descendants in the SMART assay, while the results obtained in this test for the monoterpene indole alkaloid 1 isolated from this extract. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison of the in vivo and in vitro genotoxicity of glyphosate isopropylamine salt in three different organisms

Directory of Open Access Journals (Sweden)

Carlos Alvarez-Moya

2014-01-01

Full Text Available There is considerable controversy with regard to the genotoxicity of glyphosate, with some reports stating that this compound is non-toxic for fish, birds and mammals. In this work, we used the comet assay to examine the genotoxicity of glyphosate isopropylamine (0.7, 7, 70 and 700 µM in human lymphocytes, erythrocytes of Oreochromis niloticus and staminal nuclei of Tradescantia (4430 in vitro and in vivo. Cells, nuclei and fish that had and had not been exposed to 5 mM N-nitrosodiethylamine (NDEA were used as positive and negative controls, respectively. Significant (p 7 µM, whereas in vitro, glyphosphate was genotoxic in human lymphocytes and Tradescantia hairs at > 0.7 µM. These results indicate that glyphosate is genotoxic in the cells and organisms studied at concentrations of 0.7-7 µM.

Electrochemical Genotoxicity Assay Based on a SOS/umu Test Using Hydrodynamic Voltammetry in a Droplet

Science.gov (United States)

Kuramitz, Hideki; Sazawa, Kazuto; Nanayama, Yasuaki; Hata, Noriko; Taguchi, Shigeru; Sugawara, Kazuharu; Fukushima, Masami

2012-01-01

The SOS/umu genotoxicity assay evaluates the primary DNA damage caused by chemicals from the β-galactosidase activity of S. typhimurium. One of the weaknesses of the common umu test system based on spectrophotometric detection is that it is unable to measure samples containing a high concentration of colored dissolved organic matters, sediment, and suspended solids. However, umu tests with electrochemical detection techniques prove to be a better strategy because it causes less interference, enables the analysis of turbid samples and allows detection even in small volumes without loss of sensitivity. Based on this understanding, we aim to develop a new umu test system with hydrodynamic chronoamperometry using a rotating disk electrode (RDE) in a microliter droplet. PAPG when used as a substrate is not electroactive at the potential at which PAP is oxidized to p-quinone imine (PQI), so the current response of chronoamperometry resulting from the oxidation of PAP to PQI is directly proportional to the enzymatic activity of S. typhimurium. This was achieved by performing genotoxicity tests for 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide (AF-2) and 2-aminoanthracene (2-AA) as model genotoxic compounds. The results obtained in this study indicated that the signal detection in the genotoxicity assay based on hydrodynamic voltammetry was less influenced by the presence of colored components and sediment particles in the samples when compared to the usual colorimetric signal detection. The influence caused by the presence of humic acids (HAs) and artificial sediment on the genotoxic property of selected model compounds such as 4-nitroquinoline-N-oxide (4-NQO), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), 1,8-dinitropyrene (1,8-DNP) and 1-nitropyrene (1-NP) were also investigated. The results showed that the genotoxicity of 1-NP and MX changed in the presence of 10 mg·L−1 HAs. The genotoxicity of tested chemicals with a high hydrophobicity such as 1,8-DNP

Independent effects of endogenous and exogenous attention in touch.

Science.gov (United States)

Jones, Alexander; Forster, Bettina

2013-12-01

Endogenous and exogenous attention in touch have typically been investigated separately. Here we use a double-cueing paradigm manipulating both types of orienting in each trial. Bilateral endogenous cues induced long-lasting facilitation of endogenous attention up to 2 s. However, the exogenous cue only elicited an effect at short intervals. Our results favour a supramodal account of attention and this study provides new insight into how endogenous and exogenous attention operates in the tactile modality.

Protecting Cryptographic Memory against Tampering Attack

DEFF Research Database (Denmark)

Mukherjee, Pratyay

In this dissertation we investigate the question of protecting cryptographic devices from tampering attacks. Traditional theoretical analysis of cryptographic devices is based on black-box models which do not take into account the attacks on the implementations, known as physical attacks. In prac......In this dissertation we investigate the question of protecting cryptographic devices from tampering attacks. Traditional theoretical analysis of cryptographic devices is based on black-box models which do not take into account the attacks on the implementations, known as physical attacks....... In practice such attacks can be executed easily, e.g. by heating the device, as substantiated by numerous works in the past decade. Tampering attacks are a class of such physical attacks where the attacker can change the memory/computation, gains additional (non-black-box) knowledge by interacting...... with the faulty device and then tries to break the security. Prior works show that generically approaching such problem is notoriously difficult. So, in this dissertation we attempt to solve an easier question, known as memory-tampering, where the attacker is allowed tamper only with the memory of the device...

New investigations into the genotoxicity of cobalt compounds and their impact on overall assessment of genotoxic risk.

Science.gov (United States)

Kirkland, David; Brock, Tom; Haddouk, Hasnaà; Hargeaves, Victoria; Lloyd, Melvyn; Mc Garry, Sarah; Proudlock, Raymond; Sarlang, Séverine; Sewald, Katherina; Sire, Guillaume; Sokolowski, Andrea; Ziemann, Christina

2015-10-01

The genotoxicity of cobalt metal and cobalt compounds has been widely studied. Several publications show induction of chromosomal aberrations, micronuclei or DNA damage in mammalian cells in vitro in the absence of S9. Mixed results were seen in gene mutation studies in bacteria and mammalian cells in vitro, and in chromosomal aberration or micronucleus assays in vivo. To resolve these inconsistencies, new studies were performed with soluble and poorly soluble cobalt compounds according to OECD-recommended protocols. Induction of chromosomal damage was confirmed in vitro, but data suggest this may be due to oxidative stress. No biologically significant mutagenic responses were obtained in bacteria, Tk(+/-) or Hprt mutation tests. Negative results were also obtained for chromosomal aberrations (in bone marrow and spermatogonia) and micronuclei at maximum tolerated doses in vivo. Poorly soluble cobalt compounds do not appear to be genotoxic. Soluble compounds do induce some DNA and chromosomal damage in vitro, probably due to reactive oxygen. The absence of chromosome damage in robust GLP studies in vivo suggests that effective protective processes are sufficient to prevent oxidative DNA damage in whole mammals. Overall, there is no evidence of genetic toxicity with relevance for humans of cobalt substances and cobalt metal. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Exploiting Hardware Vulnerabilities to Attack Embedded System Devices: a Survey of Potent Microarchitectural Attacks

Directory of Open Access Journals (Sweden)

Apostolos P. Fournaris

2017-07-01

Full Text Available Cyber-Physical system devices nowadays constitute a mixture of Information Technology (IT and Operational Technology (OT systems that are meant to operate harmonically under a security critical framework. As security IT countermeasures are gradually been installed in many embedded system nodes, thus securing them from many well-know cyber attacks there is a lurking danger that is still overlooked. Apart from the software vulnerabilities that typical malicious programs use, there are some very interesting hardware vulnerabilities that can be exploited in order to mount devastating software or hardware attacks (typically undetected by software countermeasures capable of fully compromising any embedded system device. Real-time microarchitecture attacks such as the cache side-channel attacks are such case but also the newly discovered Rowhammer fault injection attack that can be mounted even remotely to gain full access to a device DRAM (Dynamic Random Access Memory. Under the light of the above dangers that are focused on the device hardware structure, in this paper, an overview of this attack field is provided including attacks, threat directives and countermeasures. The goal of this paper is not to exhaustively overview attacks and countermeasures but rather to survey the various, possible, existing attack directions and highlight the security risks that they can pose to security critical embedded systems as well as indicate their strength on compromising the Quality of Service (QoS such systems are designed to provide.

Seven deadliest USB attacks

CERN Document Server

Anderson, Brian

2010-01-01

Do you need to keep up with the latest hacks, attacks, and exploits effecting USB technology? Then you need Seven Deadliest USB Attacks. This book pinpoints the most dangerous hacks and exploits specific to USB, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks detailed in this book include: USB Hacksaw USB Switchblade USB Based Virus/Malicous Code Launch USB Device Overflow RAMdum

Approaches to the risk assessment of genotoxic carcinogens in food: a critical appraisal.

Science.gov (United States)

O'Brien, J; Renwick, A G; Constable, A; Dybing, E; Müller, D J G; Schlatter, J; Slob, W; Tueting, W; van Benthem, J; Williams, G M; Wolfreys, A

2006-10-01

The present paper examines the particular difficulties presented by low levels of food-borne DNA-reactive genotoxic carcinogens, some of which may be difficult to eliminate completely from the diet, and proposes a structured approach for the evaluation of such compounds. While the ALARA approach is widely applicable to all substances in food that are both carcinogenic and genotoxic, it does not take carcinogenic potency into account and, therefore, does not permit prioritisation based on potential risk or concern. In the absence of carcinogenicity dose-response data, an assessment based on comparison with an appropriate threshold of toxicological concern may be possible. When carcinogenicity data from animal bioassays are available, a useful analysis is achieved by the calculation of margins of exposure (MOEs), which can be used to compare animal potency data with human exposure scenarios. Two reference points on the dose-response relationship that can be used for MOE calculation were examined; the T25 value, which is derived from linear extrapolation, and the BMDL10, which is derived from mathematical modelling of the dose-response data. The above approaches were applied to selected food-borne genotoxic carcinogens. The proposed approach is applicable to all substances in food that are DNA-reactive genotoxic carcinogens and enables the formulation of appropriate semi-quantitative advice to risk managers.

Cytotoxic and genotoxic studies of essential oil from Rosa damascene Mill., Kashan, Iran.

Science.gov (United States)

Shokrzadeh, Mohammad; Habibi, Emran; Modanloo, Mona

2017-08-01

Aim Rosa damascene Mill. belongs to the family of Roseaceae and its essential oil is produced in large amounts in Iran. The wide application of rose oil has raised questions about potential adverse health effects. We have investigated cytotoxic activity and genotoxic effects of Rosa oil from Kashan, Iran. Methods The cytotoxic effect and IC50 of the essential oil on the cell lines was studied followed by MTT assay. In this assay mitochondrial oxidoreductase enzymes with reducing the tetrazolium dye MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) reflect the number of viable cells. Genotoxic effect of the oil was evaluated by micronucleus assay by evaluating produced micronuclei due to cytogenetic damage in binucleated lymphocytes. Results The results showed that essential oil significantly had cytotoxic and genotoxic effects at doses over 10µg/mL (pessential oil of Rose showed lower IC50 in cancer cell line (A549) in comparison with the normal cell line (NIH3T3). Conclusion Cytotoxic and genotoxic properties of essential oil of Rose in Kashan, Iran, are safe at a dose of 10µg/mL. Also, a good cytotoxic effect was shown and could be introduced as an anticancer compound. Further studies are needed with regard to anti-cancer effects of Rose essential oil. Copyright© by the Medical Assotiation of Zenica-Doboj Canton.

Seven Deadliest Unified Communications Attacks

CERN Document Server

York, Dan

2010-01-01

Do you need to keep up with the latest hacks, attacks, and exploits effecting Unified Communications technology? Then you need Seven Deadliest Unified Communication Attacks. This book pinpoints the most dangerous hacks and exploits specific to Unified Communications, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks featured in this book include: UC Ecosystem Attacks Insecure Endpo

Invisible Trojan-horse attack.

Science.gov (United States)

Sajeed, Shihan; Minshull, Carter; Jain, Nitin; Makarov, Vadim

2017-08-21

We demonstrate the experimental feasibility of a Trojan-horse attack that remains nearly invisible to the single-photon detectors employed in practical quantum key distribution (QKD) systems, such as Clavis2 from ID Quantique. We perform a detailed numerical comparison of the attack performance against Scarani-Ac´ın-Ribordy-Gisin (SARG04) QKD protocol at 1924 nm versus that at 1536 nm. The attack strategy was proposed earlier but found to be unsuccessful at the latter wavelength, as reported in N. Jain et al., New J. Phys. 16, 123030 (2014). However at 1924 nm, we show experimentally that the noise response of the detectors to bright pulses is greatly reduced, and show by modeling that the same attack will succeed. The invisible nature of the attack poses a threat to the security of practical QKD if proper countermeasures are not adopted.

Whispering through DDoS attack

Directory of Open Access Journals (Sweden)

Miralem Mehic

2016-03-01

Full Text Available Denial of service (DoS attack is an attempt of the attacker to disable victim's machine by depleting network or computing resources. If this attack is performed with more than one machine, it is called distributed denial of service (DDoS attack. Covert channels are those channels which are used for information transmission even though they are neither designed nor intended to transfer information at all. In this article, we investigated the possibility of using of DDoS attack for purposes of hiding data or concealing the existing covert channel. In addition, in this paper we analyzed the possibility of detection of such covert communication with the well-known statistical method. Also, we proposed the coordination mechanisms of the attack which may be used. A lot of research has been done in order to describe and prevent DDoS attacks, yet research on steganography on this field is still scarce.

Genotoxic damage in cultured human peripheral blood lymphocytes ...

African Journals Online (AJOL)

Falaq Naz

2012-06-29

Jun 29, 2012 ... Genotoxic damage in cultured human peripheral blood lymphocytes of oral ... catechol estrogens and quinines, via redox reactions causes oxidative damage to .... volume was prepared for each donor. About, 0.8 ml of cell sus .... duce the adverse effects of OCs, such as the reduction in the estrogen content.

Heart attack - discharge

Science.gov (United States)

... and lifestyle Cholesterol - drug treatment Controlling your high blood pressure Deep vein thrombosis - discharge Dietary fats explained Fast food tips Heart attack - discharge Heart attack - what to ask your doctor Heart bypass ... pacemaker - discharge High blood pressure - what to ask your doctor How to read ...

Ground and surface water for drinking: a laboratory study on genotoxicity using plant tests

Directory of Open Access Journals (Sweden)

Donatella Feretti

2012-02-01

Full Text Available Surface waters are increasingly utilized for drinking water because groundwater sources are often polluted. Several monitoring studies have detected the presence of mutagenicity in drinking water, especially from surface sources due to the reaction of natural organic matter with disinfectant. The study aimed to investigate the genotoxic potential of the products of reaction between humic substances, which are naturally present in surface water, and three disinfectants: chlorine dioxide, sodium hypochlorite and peracetic acid. Commercial humic acids dissolved in distilled water at different total organic carbon (TOC concentrations were studied in order to simulate natural conditions of both ground water (TOC=2.5 mg/L and surface water (TOC=7.5 mg/L. These solutions were treated with the biocides at a 1:1 molar ratio of C:disinfectant and tested for genotoxicity using the anaphase chromosomal aberration and micronucleus tests in Allium cepa, and the Vicia faba and Tradescantia micronucleus tests. The tests were carried out after different times and with different modes of exposure, and at 1:1 and 1:10 dilutions of disinfected and undisinfected humic acid solutions. A genotoxic effect was found for sodium hypochlorite in all plant tests, at both TOCs considered, while chlorine dioxide gave positive results only with the A.cepa tests. Some positive effects were also detected for PAA (A.cepa and Tradescantia. No relevant differences were found in samples with different TOC values. The significant increase in all genotoxicity end-points induced by all tested disinfectants indicates that a genotoxic potential is exerted even in the presence of organic substances at similar concentrations to those frequently present in drinking water.

Environmental genotoxicity and risk assessment in the Gulf of Riga (Baltic Sea) using fish, bivalves, and crustaceans.

Science.gov (United States)

Butrimavičienė, Laura; Baršienė, Janina; Greiciūnaitė, Janina; Stankevičiūtė, Milda; Valskienė, Roberta

2018-06-21

Environmental genotoxicity in the Gulf of Riga was assessed using different bioindicators (fish, clams, and isopods) collected from 14 study stations. Comparison of genotoxicity responses (micronuclei (MN) and nuclear buds (NB)) in blood erythrocytes of herring (Clupea harengus), eelpout (Zoarces viviparous), and flounder (Platichthys flesus) revealed the species- and site-specific differences. For the first time, the analysis of genotoxicity was carried out in gill cells of isopods Saduria entomon. The highest inductions of MN and NB in gill cells of investigated S. entomon and clams (Macoma balthica) were evaluated in specimens from station 111A (offshore zone). In fish, the highest incidences of MN were measured in eelpout and in herring collected in the southern part of Gulf of Riga (station GOR3/41S). Moreover, in the southern coastal area, the assessment of genotoxicity risk (according to micronuclei levels) indicated exceptionally high risk for flounder, eelpout, and clams.

High throughput comet assay to study genotoxicity of nanomaterials

Directory of Open Access Journals (Sweden)

Naouale El Yamani

2015-06-01

Full Text Available The unique physicochemical properties of engineered nanomaterials (NMs have accelerated their use in diverse industrial and domestic products. Although their presence in consumer products represents a major concern for public health safety, their potential impact on human health is poorly understood. There is therefore an urgent need to clarify the toxic effects of NMs and to elucidate the mechanisms involved. In view of the large number of NMs currently being used, high throughput (HTP screening technologies are clearly needed for efficient assessment of toxicity. The comet assay is the most used method in nanogenotoxicity studies and has great potential for increasing throughput as it is fast, versatile and robust; simple technical modifications of the assay make it possible to test many compounds (NMs in a single experiment. The standard gel of 70-100 μL contains thousands of cells, of which only a tiny fraction are actually scored. Reducing the gel to a volume of 5 μL, with just a few hundred cells, allows twelve gels to be set on a standard slide, or 96 as a standard 8x12 array. For the 12 gel format, standard slides precoated with agarose are placed on a metal template and gels are set on the positions marked on the template. The HTP comet assay, incorporating digestion of DNA with formamidopyrimidine DNA glycosylase (FPG to detect oxidised purines, has recently been applied to study the potential induction of genotoxicity by NMs via reactive oxygen. In the NanoTEST project we investigated the genotoxic potential of several well-characterized metal and polymeric nanoparticles with the comet assay. All in vitro studies were harmonized; i.e. NMs were from the same batch, and identical dispersion protocols, exposure time, concentration range, culture conditions, and time-courses were used. As a kidney model, Cos-1 fibroblast-like kidney cells were treated with different concentrations of iron oxide NMs, and cells embedded in minigels (12

Genotoxicity study of an experimental beverage made with quinua, kiwicha and kañiwa

Directory of Open Access Journals (Sweden)

Francia D.P. Huaman

2014-12-01

Full Text Available Genotoxic evaluation is an important step for a product that is aimed for human consumption. A beverage composed of pseudocereals with highly nutritious elements like quinua (Chenopodium quinoa Willd., kiwicha (Amaranthus caudatus L. and kañiwa (Chenopodium pallidicaule Aellen was prepared to reduce lipid contents in a group of volunteers. The objective of the present study is to evaluate the genotoxic potential of an experimental beverage using two in vitro tests that have been validated by international agencies. For the Ames test, two strains of Salmonella typhimurium (TA98 and TA100 with and without microsomal fraction (S9 were used. Four doses of the beverage were tested and also a possible protective effect (same four doses of beverage added to plates with mutagens. Cultures of binucleated lymphocytes and five doses of the beverage were used for the micronucleus test. Both Ames and the micronucleus tests showed the beverage has not genotoxic effect in all tested doses. However, in evaluating the possible protective effect of the beverage, it would be evident that on the contrary, the mutagenic effect of mutagens used for each strain is enhanced. These results suggest that additional tests should be performed to check the genotoxic potential of this beverage before consumption.

Exposure to sorbitol during lactation causes metabolic alterations and genotoxic effects in rat offspring.

Science.gov (United States)

Cardoso, Felipe S; Araujo-Lima, Carlos F; Aiub, Claudia A F; Felzenszwalb, Israel

2016-10-17

Sorbitol is a polyol used by the food industry as a sweetener. Women are consuming diet and light products containing sorbitol during pregnancy and in the postnatal period to prevent themselves from excessive weight gain and maintain a slim body. Although there is no evidence for the genotoxicity of sorbitol in the perinatal period, this study focused on evaluating the effects of the maternal intake of sorbitol on the biochemical and toxicological parameters of lactating Wistar rat offspring after 14days of mother-to-offspring exposure. A dose-dependent reduction of offspring length was observed. An increase in sorbitol levels determined in the milk was also observed. However, we detected an inverse relationship between the exposition dose in milk fructose and triacylglycerols concentrations. There was an increase in the plasmatic levels of ALT, AST and LDLc and a decrease in proteins, cholesterol and glucose levels in the offspring. Sorbitol exposure caused hepatocyte genotoxicity, including micronuclei induction. Maternal sorbitol intake induced myelotoxicity and myelosuppression in their offspring. The Comet assay of the blood cells detected a dose-dependent genotoxic response within the sorbitol-exposed offspring. According to our results, sorbitol is able to induce important metabolic alterations and genotoxic responses in the exposed offspring. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Genotoxicity of styrene oligomers extracted from polystyrene intended for use in contact with food

Directory of Open Access Journals (Sweden)

Makoto Nakai

2014-01-01

Full Text Available Here, we conducted in vitro genotoxicity tests to evaluate the genotoxicity of styrene oligomers extracted from polystyrene intended for use in contact with food. Styrene oligomers were extracted with acetone and the extract was subjected to the Ames test (OECD test guideline No. 471 and the in vitro chromosomal aberration test (OECD test guideline No. 473 under good laboratory practice conditions. The concentrations of styrene dimers and trimers in the concentrated extract were 540 and 13,431 ppm, respectively. Extraction with acetone provided markedly higher concentrations of styrene oligomers compared with extraction with 50% ethanol aqueous solution, which is the food simulant currently recommended for use in safety assessments of polystyrene by both the United States Food and Drug Administration and the European Food Safety Authority. And these high concentrations of styrene dimers and trimers were utilized for the evaluation of genotoxicity in vitro. Ames tests using five bacterial tester strains were negative both in the presence or absence of metabolic activation. The in vitro chromosomal aberration test using Chinese hamster lung cells (CHL/IU was also negative. Together, these results suggest that the risk of the genotoxicity of styrene oligomers that migrate from polystyrene food packaging into food is very low.

Genotoxicity and antigenotoxicity assessment of shiitake (Lentinula edodes (Berkeley Pegler using the Comet assay

Directory of Open Access Journals (Sweden)

CK Miyaji

2004-01-01

Full Text Available The mushroom shiitake (Lentinula edodes (Berkeley Pegler is been widely consumed in many countries, including Brazil, because of its pleasant flavor and reports of its therapeutic properties, although there is little available information on the genotoxicity and/or antigenotoxicity of this mushroom. We used the Comet assay and HEp-2 cells to evaluate the in vitro genotoxic and antigenotoxic activity of aqueous extracts of shiitake prepared in three different concentrations (0.5, 1.0 and 1.5 mg/mL and three different temperatures (4, 22 and 60 °C, using methyl methanesulfonate (MMS as a positive control and untreated cells as a negative control. Two concentrations (1.0 and 1.5 mg/mL of extract prepared at 4 °C and all of the concentrations prepared at 22 ± 2 and 60 °C showed moderate genotoxic activity. To test the protective effect of the three concentrations of the extracts against the genotoxicity induced by methyl methanesulfonate, three protocols were used: pre-treatment, simultaneous-treatment and post-treatment. Treatments were repeated for all combinations of preparation temperature and concentration. Two extracts (22 ± 2 °C 1.0 mg/mL (simultaneous-treatment and 4 °C 0.5 mg/mL (post-treatment showed antigenotoxic activity.

Benzene-induced genotoxicity in mice in vivo detected by the alkaline comet assay

DEFF Research Database (Denmark)

Tuo, J; Loft, S; Thomsen, M S

1996-01-01

was further increased to 5.4-fold and 6.6-fold of the control values, respectively (p propylene glycol (5 microliters/g b.wt., twice with a 60-min interval), a selective CYP2E1 inhibitor, reduced the increase in the tail length by about half at all doses in both cell types (p ...The myelotoxic and genotoxic effects of benzene have been related to oxidative DNA damage after metabolism by CYP2E1. Single cell gel electrophoresis (alkaline comet assay) detects DNA damage and may thus be a convenient method for the study of benzene genotoxicity. Benzene exposure to NMRI mice.......01). By comparing our data with those from genotoxicity studies on benzene using other methods, we conclude that the 'alkaline comet assay' is a sensitive method to detect DNA damage induced by benzene. We also infer that CYP2E1 contributes, at least partly, to the formation of the 'comet'-inducing metabolites...

Eco- and genotoxicity profiling of a rapeseed biodiesel using a battery of bioassays.

Science.gov (United States)

Eck-Varanka, Bettina; Kováts, Nora; Horváth, Eszter; Ferincz, Árpád; Kakasi, Balázs; Nagy, Szabolcs Tamás; Imre, Kornélia; Paulovits, Gábor

2018-04-30

Biodiesel is considered an important renewable energy source but still there is some controversy about its environmental toxicity, especially to aquatic life. In our study, the toxicity of water soluble fraction of biodiesel was evaluated in relatively low concentrations using a battery of bioassays: Vibrio fischeri bioluminescence inhibition, Sinapis alba root growth inhibition, Daphnia magna immobilization, boar semen live/dead ratio and DNA fragmentation and Unio pictorum micronucleus test. While the S. alba test indicated nutritive (stimulating) effect of the sample, the biodiesel exerted toxic effect in the aquatic tests. D. magna was the most sensitive with EC 50 value of 0.0226%. For genotoxicity assessment, the mussel micronucleus test (MNT) was applied, detecting considerable genotoxic potential of the biodiesel sample: it elucidated micronuclei formation already at low concentration of 3.3%. Although this test has never been employed in biodiesel eco/genotoxicity assessments, it seems a promising tool, based on its appropriate sensitivity, and representativity. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of Boron Toxicity on Oxidative Stress and Genotoxicity in Wheat (Triticum aestivum L.).

Science.gov (United States)

Çatav, Şükrü Serter; Genç, Tuncer Okan; Kesik Oktay, Müjgan; Küçükakyüz, Köksal

2018-04-01

Boron (B) toxicity, which occurs in semi-arid and arid environments, can adversely affect the growth and yield of many plants. The aim of this study was to determine the effects of different concentrations of boric acid (3, 6, 9 and 12 mM) on growth, oxidative stress and genotoxicity parameters in root and shoot tissues of wheat seedlings. Our results indicate that B stress inhibits root and shoot growth of wheat in a concentration-dependent manner, and leads to increases in TBARS and H 2 O 2 contents in shoot tissue. Moreover, our findings suggest that high concentrations of B may exert a genotoxic effect on wheat. To the best of our knowledge, this is the first report to evaluate the effect of B stress on genotoxicity in both root and shoot tissues of wheat.

Photochemical fate and eco-genotoxicity assessment of the drug etodolac

Energy Technology Data Exchange (ETDEWEB)

Passananti, Monica [Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, via Cintia, 4, 80126 Napoli (Italy); Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand (ICCF) UMR 6296, BP 10448, F-63000 Clermont-Ferrand (France); Lavorgna, Margherita [Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, I-81100 Caserta (Italy); Iesce, Maria Rosaria, E-mail: iesce@unina.it [Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, via Cintia, 4, 80126 Napoli (Italy); DellaGreca, Marina [Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, via Cintia, 4, 80126 Napoli (Italy); Brigante, Marcello [Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand (ICCF) UMR 6296, BP 10448, F-63000 Clermont-Ferrand (France); Criscuolo, Emma [Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, I-81100 Caserta (Italy); Cermola, Flavio [Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, via Cintia, 4, 80126 Napoli (Italy); Isidori, Marina, E-mail: marina.isidori@unina2.it [Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, I-81100 Caserta (Italy)

2015-06-15

The photochemical behavior of etodolac was investigated under various irradiation conditions. Kinetic data were obtained after irradiation of 10{sup −4} M aqueous solutions by UVB, UVA and direct exposure to sunlight. The Xenon lamp irradiation was used in order to determine the photodegradation quantum yield under sun-simulated condition (ϕ{sub sun}). The value was determined to be = 0.10 ± 0.01. In order to obtain photoproducts and for mechanistic purposes, experiments were carried out on more concentrated solutions by exposure to sunlight and to UVA and UVB lamps. The drug underwent photooxidative processes following an initial oxygen addition to the double bond of the five membered ring and was mainly converted into a spiro compound and a macrolactam. Ecotoxicity tests were performed on etodolac, its photostable spiro derivative and its sunlight irradiation mixture on two different aquatic trophic levels, plants (algae) and invertebrates (rotifers and crustaceans). Mutagenesis and genotoxicity were detected on bacterial strains. The results showed that only etodolac had long term effects on rotifers although at concentrations far from environmental detection values. A mutagenic and genotoxic potential was found for its derivative. - Highlights: • Photochemical transformation of etodolac occurs in the environment. • Etodolac was slightly toxic in the long term for some aquatic organisms. • A mutagenic and genotoxic potential was found for etodolac photostable derivative.

Does Caesalpinia bonducella ameliorate genotoxicity? An in vitro ...

African Journals Online (AJOL)

The aim of the study is to investigate the antimutagenic and antigenotoxic potential of alcoholic extracts of C. bonducella against methyl methane sulfonate (MMS) induced genotoxicity. In this experiment we have used in vitro method i.e., human lymphocyte culture and in vivo method in bone marrow cells of albino mice, ...

Genotoxicity and mutagenicity of solid waste leachates: A review

African Journals Online (AJOL)

user

2013-07-03

Jul 3, 2013 ... There is need for a shift from waste disposal to sustainable waste management. Awareness on possible health ... Key words: Solid waste leachate, genotoxicity, mutagenicity, environmental pollution. INTRODUCTION. Solid wastes .... landfills and incineration residues from Japan include persistent organic ...

Exogenous sample contamination. Sources and interference.

Science.gov (United States)

Cornes, Michael P

2016-12-01

Clinical laboratory medicine is involved in the vast majority of patient care pathways. It has been estimated that pathology results inform 60-70% of critical patient care decisions. The primary goal of the laboratory is to produce precise and accurate results which reflect the true situation in vivo. It is not surprising that interference occurs in laboratory analysis given the complexity of some of the assays used to perform them. Interference is defined as "the effect of a substance upon any step in the determination of the concentration or catalytic activity of the metabolite". Exogenous interferences are defined as those that derive from outside of the body and are therefore not normally found in a specimen and can cause either a positive or negative bias in analytical results. Interferences in analysis can come from various sources and can be classified as endogenous or exogenous. Exogenous substances could be introduced at any point in the sample journey. The laboratory must take responsibility for the quality of results produced. It has a responsibility to have processes in place to identify and minimise the occurrence and effect contamination and interference. To do this well the laboratory needs to work with clinicians and manufacturers. Failure to identify an erroneous result could have an impact on patient care, patient safety and also on hospital budgets. However it is not always easy to recognise interferences. This review summarises the types and sources of exogenous interference and some steps to minimise the impact they have. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Genotoxicity of topoisomerase II inhibitors: An anti-infective perspective

International Nuclear Information System (INIS)

Smart, Daniel J.

2008-01-01

At present, an inevitable consequence of a chemical's inhibitory activity on key regulators of DNA topology in bacteria, the type II topoisomerases, is a less pronounced effect on their eukaryotic counterparts. In the context of anti-infectives drug development, this may pose a risk to patient safety as inhibition of eukaryotic type II topoisomerases (TOPO II) can result in the generation of DNA double-strand breaks (DSBs), which have the potential to manifest as mutations, chromosome breakage or cell death. The biological effects of several TOPO II inhibitors in mammalian cells are described herein; their modulation of DSB damage response parameters is examined and evidence for the existence of a threshold concept for genotoxicity and its relevance in safety assessment is discussed. The potential utility of γH2AX, a promising and highly sensitive molecular marker for DSBs, in a novel genotoxicity 'pre-screen' to conventional assays is also highlighted

Attack Trees for Practical Security Assessment: Ranking of Attack Scenarios with ADTool 2.0

NARCIS (Netherlands)

Gadyatskaya, Olga; Jhawar, Ravi; Kordy, P.T.; Lounis, Karim; Mauw, Sjouke; Trujillo-Rasua, Rolando

2016-01-01

In this tool demonstration paper we present the ADTool2.0: an open-source software tool for design, manipulation and analysis of attack trees. The tool supports ranking of attack scenarios based on quantitative attributes entered by the user; it is scriptable; and it incorporates attack trees with

New investigations into the genotoxicity of cobalt compounds and their impact on overall assessment of genotoxic risk

OpenAIRE

Kirkland, David; Brock, Tom; Haddouk, Hasnaà; Hargeaves, Victoria; Lloyd, Melvyn; Mc Garry, Sarah; Proudlock, Raymond; Sarlang, Séverine; Sewald, Katherina; Sire, Guillaume; Sokolowski, Andrea; Ziemann, Christina

2015-01-01

The genotoxicity of cobalt metal and cobalt compounds has been widely studied. Several publications show induction of chromosomal aberrations, micronuclei or DNA damage in mammalian cells in vitro in the absence of S9. Mixed results were seen in gene mutation studies in bacteria and mammalian cells in vitro, and in chromosomal aberration or micronucleus assays in vivo. To resolve these inconsistencies, new studies were performed with soluble and poorly soluble cobalt compounds according to OE...

Genotoxicity detected in wild mice living in a highly polluted wetland area in south western Spain

Energy Technology Data Exchange (ETDEWEB)

Mateos, Santiago; Daza, Paula; Dominguez, Inmaculada; Cardenas, Jose Antonio [University of Seville, Department of Cell Biology, Faculty of Biology, Avenida de la Reina Mercedes no 6, E-41012 Seville (Spain); Cortes, Felipe [University of Seville, Department of Cell Biology, Faculty of Biology, Avenida de la Reina Mercedes no 6, E-41012 Seville (Spain)], E-mail: cortes@us.es

2008-06-15

A field study was carried out in the south of the Iberian Peninsula in an industrial area in the neighbourhood of Huelva city, SW Spain, and in a natural area (Donana National Park) for comparison, to estimate the genetic risk induced by environmental pollution in wild mice. Genotoxic effects in a sentinel organism, the Algerian mice (Mus spretus) free living in the industrial area were compared with animals of the same species living in the natural protected area. The single cell gel electrophoresis, or Comet assay, was performed as a genotoxicity test in peripheral blood of mice. Our results clearly show that mice free living in the contaminated area bear a high burden of genetic damage as compared with control individuals. The results suggest that the assessing of genotoxicity levels by the Comet assay in wild mice can be used as a valuable test in pollution monitoring and environmental conservation. - We have found an increased genotoxic damage in wild mice in a highly polluted area from industry, mining and agriculture in SW Spain, as assessed by the Comet assay.

Biodetection of potential genotoxic pollutants entering the human food chain through ashes used in livestock diets.

Science.gov (United States)

Sanchez-Vicente, Laura; Herraez, Elisa; Briz, Oscar; Nogales, Rogelio; Molina-Alcaide, Eduarda; Marin, Jose J G

2016-08-15

Ash derived from energy generation is used as a source of minerals in livestock feeds. The microbial biosensor recApr-Luc2 was built to detect genotoxic hazard in recycled ash. Escherichia coli SOS gene (recA, lexA, dinI and umuC) expression in response to cisplatin-induced DNA damage led to the selection of the recA promoter. The biosensor required functional RecA expression to respond to genotoxic heavy metals (Cr>Cd≈Pb), and polluted ash induced a strong recApr-Luc2 response. In human liver and intestinal cells, heavy metals induced acute toxicity (Cr>Cd>Pb) at concentrations sufficient to activate recApr-Luc2. Cytostatic effects, including genotoxicity, were cell- and metal-dependent, apart from Cr. In agreement with the recApr-Luc2 bioassay, Cr had the strongest effect in all cells. In conclusion, recApr-Luc2 could be useful for evaluating the genotoxic risk of pollutants present in ash that might be concentrated in animal products and, thus, entering the human food chain. Copyright © 2016 Elsevier Ltd. All rights reserved.

The work-averse cyber attacker model : theory and evidence from two million attack signatures

NARCIS (Netherlands)

Allodi, L.; Massacci, F.; Williams, J.

The typical cyber attacker is assumed to be all powerful and to exploit all possible vulnerabilities. In this paper we present, and empirically validate, a novel and more realistic attacker model. The intuition of our model is that an attacker will optimally choose whether to act and weaponize a new

An evaluation of the genotoxic and cytotoxic effects of the anti-obesity drugs sibutramine and fenproporex.

Science.gov (United States)

da Silva, Cristiano José; dos Santos, José Ernesto; Satie Takahashi, Catarina

2010-03-01

Anti-obesity medications deserve special considerations at the present time due to an increasing number of overweight and obese people who require these therapeutic alternatives. Obesity is positively associated with several chronic illnesses, including cancer. In this work, we evaluated the possible genotoxic and/or cytotoxic actions of two drugs, sibutramine and fenproporex, in the doses of 10, 20 and 40 mg/kg body weight (bw), administered intraperitoneally in male Swiss mice. The genotoxic effect was analyzed by comet assay and micronucleus test. We found that both drugs increased the frequency of genotoxic damage in Swiss mice, but did not present cytotoxic activities towards the polychromatic erythrocytes of the bone marrow of these animals.

Determination of heavy metals and genotoxicity of water from an ...

African Journals Online (AJOL)

Determination of heavy metals and genotoxicity of water from an artesian well ... do Amaral, Vanessa Marques de Oliveira Moraes, Luciana Pereira Silva ... environmental interest because it is the most important zinc producer district of Brazil.

Exogenous (automatic) attention to emotional stimuli: a review.

Science.gov (United States)

Carretié, Luis

2014-12-01

Current knowledge on the architecture of exogenous attention (also called automatic, bottom-up, or stimulus-driven attention, among other terms) has been mainly obtained from studies employing neutral, anodyne stimuli. Since, from an evolutionary perspective, exogenous attention can be understood as an adaptive tool for rapidly detecting salient events, reorienting processing resources to them, and enhancing processing mechanisms, emotional events (which are, by definition, salient for the individual) would seem crucial to a comprehensive understanding of this process. This review, focusing on the visual modality, describes 55 experiments in which both emotional and neutral irrelevant distractors are presented at the same time as ongoing task targets. Qualitative and, when possible, meta-analytic descriptions of results are provided. The most conspicuous result is that, as confirmed by behavioral and/or neural indices, emotional distractors capture exogenous attention to a significantly greater extent than do neutral distractors. The modulatory effects of the nature of distractors capturing attention, of the ongoing task characteristics, and of individual differences, previously proposed as mediating factors, are also described. Additionally, studies reviewed here provide temporal and spatial information-partially absent in traditional cognitive models-on the neural basis of preattention/evaluation, reorienting, and sensory amplification, the main subprocesses involved in exogenous attention. A model integrating these different levels of information is proposed. The present review, which reveals that there are several key issues for which experimental data are surprisingly scarce, confirms the relevance of including emotional distractors in studies on exogenous attention.

Applicability of in silico genotoxicity models on food and feed ingredients.

Science.gov (United States)

Vuorinen, Anna; Bellion, Phillip; Beilstein, Paul

2017-11-01

Evaluation of the genotoxic potential of food and feed ingredients is required in the development of new substances and for their registration. In addition to in vitro and in vivo assays, in silico tools such as expert alert-based and statistical models can be used for data generation. These in silico models are commonly used among the pharmaceutical industry, whereas the food industry has not widely adopted them. In this study, the applicability of in silico tools for predicting genotoxicity was evaluated, with a focus on bacterial mutagenicity, in vitro and in vivo chromosome damage assays. For this purpose, a test set of 27 food and feed ingredients including vitamins, carotenoids, and nutraceuticals with experimental genotoxicity data was constructed from proprietary data. This dataset was run through multiple models and the model applicability was analyzed. The compounds were generally within the applicability domain of the models and the models predicted the compounds correctly in most of the cases. Although the regulatory acceptance of in silico tools as single data source is still limited, the models are applicable and can be used in the safety evaluation of food and feed ingredients. Copyright © 2017 Elsevier Inc. All rights reserved.

Can Genotoxic Effect be Model Dependent in Allium Test?-An Evidence

Directory of Open Access Journals (Sweden)

Hemant Singh Rathore

2010-07-01

Full Text Available Genotoxicity of peracetic acid (PAA has been assessed in two models (protocols of Allium cepa conducting two sets of experiments to know whether the results would be model dependent. One experiment was set as per Fiskesjo's model in which Allium cepa bulbs were grown in five concentrations of peracetic acid (0.039, 0.078, 0.156, 0.312 and 0.625 ppm in tap water. Another experiment was set as per Rank and Nielson's model in which Allium cepa bulbs were first grown in tap water for 24 hours and were then further grown in the same concentrations of peracetic acid as in earlier model. Genotoxic effects of peracetic acid were assessed in both models using usual parameters i.e. shape, colour and length of root tips, mitotic index, chromosomal aberrations and cell death. Magnitude of effect differed significantly in both models. More severe genotoxic effects could be seen in Fiskesjo's model. It is suggested that root primordial cells were in G0 state in Fiskesjo's model, which presumably lacked their defense system, hence were more prone to peracetic acid toxicity. Mitotically dividing root cells in Rank and Nielsen's model were equipped with antioxidant system and were more resistant to peracetic acid

Development of a Fish Cell Biosensor System for Genotoxicity Detection Based on DNA Damage-Induced Trans-Activation of p21 Gene Expression

Directory of Open Access Journals (Sweden)

Huarong Guo

2012-09-01

Full Text Available p21CIP1/WAF1 is a p53-target gene in response to cellular DNA damage. Here we report the development of a fish cell biosensor system for high throughput genotoxicity detection of new drugs, by stably integrating two reporter plasmids of pGL3-p21-luc (human p21 promoter linked to firefly luciferase and pRL-CMV-luc (CMV promoter linked to Renilla luciferase into marine flatfish flounder gill (FG cells, referred to as p21FGLuc. Initial validation of this genotoxicity biosensor system showed that p21FGLuc cells had a wild-type p53 signaling pathway and responded positively to the challenge of both directly acting genotoxic agents (bleomycin and mitomycin C and indirectly acting genotoxic agents (cyclophosphamide with metabolic activation, but negatively to cyclophosphamide without metabolic activation and the non-genotoxic agents ethanol and D-mannitol, thus confirming a high specificity and sensitivity, fast and stable response to genotoxic agents for this easily maintained fish cell biosensor system. This system was especially useful in the genotoxicity detection of Di(2-ethylhexyl phthalate (DEHP, a rodent carcinogen, but negatively reported in most non-mammalian in vitro mutation assays, by providing a strong indication of genotoxicity for DEHP. A limitation for this biosensor system was that it might give false positive results in response to sodium butyrate and any other agents, which can trans-activate the p21 gene in a p53-independent manner.

Investigation of potential genotoxic activity using the SOS Chromotest for real paracetamol wastewater and the wastewater treated by the Fenton process.

Science.gov (United States)

Kocak, Emel

2015-01-01

The potential genotoxic activity associated with high strength real paracetamol (PCT) wastewater (COD = 40,000 mg/L, TOC = 12,000 mg/L, BOD5 = 19,320 mg/L) from a large-scale drug-producing plant in the Marmara Region, was investigated in pre- and post- treated wastewater by the Fenton process (COD = 2,920 mg/L, TOC = 880 mg/L; BOD5 = 870 mg/L). The SOS Chromotest, which is based on Escherichia coli PQ37 activities, was used for the assessment of genotoxicity. The corrected induction factors (CIF) values used as quantitative measurements of the genotoxic activity were obtained from a total of four different dilutions (100, 50, 6.25, and 0.078 % v/v.) for two samples, in triplicate, to detect potentially genotoxic activities with the SOS Chromotest. The results of the SOS Chromotest demonstrated CIFmax value of 1.24, indicating that the PCT effluent (non-treated) is genotoxic. The results of the SOS Chromotest showed an CIFmax value of 1.72, indicating that the wastewater treated by Fenton process is genotoxic. The findings of this study clearly reveal that the PCT wastewater (non-treated) samples have a potentially hazardous impact on the aquatic environment before treatment, and in the wastewater that was treated by the Fenton process, genotoxicity generally increased.

Cytotoxicity and genotoxicity property of hydroxyapatite-mullite eluates.

Science.gov (United States)

Kalmodia, Sushma; Sharma, Vyom; Pandey, Alok K; Dhawan, Alok; Basu, Bikramjit

2011-02-01

Long-term biomedical applications of implant materials may cause osteolysis, aseptic losing and toxicity. Therefore, we investigated the cytotoxic and genotoxic potential of hydroxyapatite (HA) mullite eluates in L929 mouse fibroblast cells. The spark plasma sintered HA-20% mullite biocomposite (HA20M) were ground using mortar and pestle as well as ball milling. The cells were exposed for 6 h to varying concentrations (10, 25, 50, 75 and 100%) of the eluates of HA-20% mullite (87 nm), HA (171 nm) and mullite (154 nm). The scanning electron microscopy and MTT assay revealed the concentration dependent toxicity of H20M eluate at and above 50%. The analysis of the DNA damaging potential of HA, mullite and HA20M eluates using Comet assay demonstrated a significant DNA damage by HA20M which was largely related to the presence of mullite. The results collectively demonstrate the cytotoxic and genotoxic potential of HA20M eluate in L929 cells is dependent on particle size, concentration and composition.

Web server attack analyzer

OpenAIRE

Mižišin, Michal

2013-01-01

Web server attack analyzer - Abstract The goal of this work was to create prototype of analyzer of injection flaws attacks on web server. Proposed solution combines capabilities of web application firewall and web server log analyzer. Analysis is based on configurable signatures defined by regular expressions. This paper begins with summary of web attacks, followed by detection techniques analysis on web servers, description and justification of selected implementation. In the end are charact...

Network Protection Against DDoS Attacks

Directory of Open Access Journals (Sweden)

Petr Dzurenda

2015-03-01

Full Text Available The paper deals with possibilities of the network protection against Distributed Denial of Service attacks (DDoS. The basic types of DDoS attacks and their impact on the protected network are presented here. Furthermore, we present basic detection and defense techniques thanks to which it is possible to increase resistance of the protected network or device against DDoS attacks. Moreover, we tested the ability of current commercial Intrusion Prevention Systems (IPS, especially Radware DefensePro 6.10.00 product against the most common types of DDoS attacks. We create five scenarios that are varied in type and strength of the DDoS attacks. The attacks intensity was much greater than the normal intensity of the current DDoS attacks.

Attack Tree Generation by Policy Invalidation

DEFF Research Database (Denmark)

Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, Rene Rydhof

2015-01-01

through brainstorming of experts. In this work we formalize attack tree generation including human factors; based on recent advances in system models we develop a technique to identify possible attacks analytically, including technical and human factors. Our systematic attack generation is based......Attacks on systems and organisations increasingly exploit human actors, for example through social engineering, complicating their formal treatment and automatic identification. Formalisation of human behaviour is difficult at best, and attacks on socio-technical systems are still mostly identified...... on invalidating policies in the system model by identifying possible sequences of actions that lead to an attack. The generated attacks are precise enough to illustrate the threat, and they are general enough to hide the details of individual steps....

THE GENOTOXICITY OF AMBIENT OUTDOOR AIR, A REVIEW: SALMONELLA MUTAGENICITY

Science.gov (United States)

The genotoxicity of ambient outdoor air, a review: Salmonella mutagenicityAbstractMutagens in urban air pollution come from anthropogenic sources (especially combustion sources) and are products of airborne chemical reactions. Bacterial mutation tests have been used ...

Exogenic and endogenic Europa minerals

Science.gov (United States)

Maynard-Casely, H. E.; Brand, H. E. A.; Wilson, S. A.

2016-12-01

The Galileo Near Infrared Mapping Spectrometer (NIMS) identified a significant `non-ice' component upon the surface of Jupiter's moon Europa. Current explanations invoke both endogenic and exogenic origins for this material. It has long been suggested that magnesium and sodium sulfate minerals could have leached from the rock below a putative ocean (endogenic) 1 and that sulfuric acid hydrate minerals could have been radiologically produced from ionised sulfur originally from Io's volcanoes (exogenic) 2. However, a more recent theory proposes that the `non-ice' component could be radiation damaged NaCl leached from Europa's speculative ocean 3. What if the minerals are actually from combination of both endogenic and exogenic sources? To investigate this possibility we have focused on discovering new minerals that might form in the combination of the latter two cases, that is a mixture of leached sulfates hydrates with radiologically produced sulfuric acid. To this end we have explored a number of solutions in the MgSO4-H2SO4-H2O and Na2SO4-H2SO4-H2O systems, between 80 and 280 K with synchrotron x-ray powder diffraction. We report a number of new materials formed in this these ternary systems. This suggests that it should be considered that the `non-ice' component of the Europa's surface could be a material derived from endogenic and exogenic components. 1 Kargel, J. S. Brine volcanism and the interior structures of asteroids and icy satellites. Icarus 94, 368-390 (1991). 2 Carlson, R. W., Anderson, M. S., Mehlman, R. & Johnson, R. E. Distribution of hydrate on Europa: Further evidence for sulfuric acid hydrate. Icarus 177, 461-471, doi:10.1016/j.icarus.2005.03.026 (2005). 3 Hand, K. P. & Carlson, R. W. Europa's surface color suggests an ocean rich with sodium chloride. Geophysical Research Letters, 2015GL063559, doi:10.1002/2015gl063559 (2015).

Terrorists and Suicide Attacks

National Research Council Canada - National Science Library

Cronin, Audrey K

2003-01-01

Suicide attacks by terrorist organizations have become more prevalent globally, and assessing the threat of suicide attacks against the United States and its interests at home and abroad has therefore...

Stochastic Model of TCP SYN Attacks

Directory of Open Access Journals (Sweden)

Simona Ramanauskaitė

2011-08-01

Full Text Available A great proportion of essential services are moving into internet space making the threat of DoS attacks even more actual. To estimate the real risk of some kind of denial of service (DoS attack in real world is difficult, but mathematical and software models make this task easier. In this paper we overview the ways of implementing DoS attack models and offer a stochastic model of SYN flooding attack. It allows evaluating the potential threat of SYN flooding attacks, taking into account both the legitimate system flow as well as the possible attack power. At the same time we can assess the effect of such parameters as buffer capacity, open connection storage in the buffer or filte­ring efficiency on the success of different SYN flooding attacks. This model can be used for other type of memory depletion denial of service attacks.Article in Lithuanian

In vitro and in vivo genotoxicity assessment of HI-6 dimethanesulfonate/oxime.

Science.gov (United States)

Nakab, Lauren; Bardot, Isabelle; Bardot, Sébastien; Simar, Sophie; Marzin, Daniel; Nesslany, Fabrice

2014-03-01

Organophosphate compounds, which induce organophosphate poisoning, were originally used as pesticides. But this type of product has also been used as warfare nerve agent like sarin, soman, Russian VX, or tabun. HI-6-dimethanesulfonate is a salt of the oxime HI-6 used in the treatment of nerve-agent poisoning. It is known to be the best re-activator component of inactivated acetyl cholinesterase. HI-6-dimethanesulfonate has shown a higher level of solubility with similar potency to reactivate acetyl cholinesterase and a similar pharmacokinetics profile compared with HI-6 dichloride. HI-6 dimethanesulfonate was tested for its mutagenic and genotoxic potential by use of the standard ICH S2R (1) battery for the evaluation of pharmaceuticals. HI-6-dimethanesulfonate was mutagenic in the Ames test only in the presence of metabolic activation. In the mutation assay at the Tk locus in L5178Y mouse-lymphoma cells, HI-6-dimethanesulfonate showed mutagenic activity both with and without metabolic activation, with a significant increase in small colonies. The effects were in favour of a clastogenic activity. It was concluded that the compound was mutagenic and possibly clastogenic in vitro. In contrast, the in vivo micronucleus test in rat bone-marrow did not demonstrate any genotoxic activity and the Comet assay performed in rat liver did not show any statistically or biologically significant increases in DNA strand-breaks. The results of both in vivo studies performed on two different organs with two endpoints are sufficient to conclude the absence of a genotoxic hazard in vivo and to consider that there is no genotoxic concern in humans for HI-6-dimethanesulfonate. Copyright © 2014 Elsevier B.V. All rights reserved.

A novel pathway to detect and cope with exogenous dsDNA.

Science.gov (United States)

Kobayashi, Shouhei; Haraguchi, Tokuko

2015-01-01

How a living cell responds to exogenous materials is one of the fundamental questions in the life sciences. In particular, understanding the mechanisms by which a cell recognizes exogenous double-stranded DNA (dsDNA) is important for immunology research because it will facilitate the control of pathogen infections that entail the presence of exogenous dsDNA in the cytoplasm of host cells. Several cytosolic dsDNA sensor proteins that trigger innate immune responses have been identified and the downstream signaling pathways have been investigated. However, the events that occur at the site of exogenous dsDNA when it is exposed to the cytosol of the host cell remain unknown. Using dsDNA-coated polystyrene beads incorporated into living cells, we recently found that barrier-to-autointegration factor (BAF) binds to the exogenous dsDNA immediately after its appearance in the cytosol and plays a role in DNA avoidance of autophagy. Our findings reveal a novel pathway in which BAF plays a key role in the detection of and response to exogenous dsDNA.

Attack Trees with Sequential Conjunction

NARCIS (Netherlands)

Jhawar, Ravi; Kordy, Barbara; Mauw, Sjouke; Radomirović, Sasa; Trujillo-Rasua, Rolando

2015-01-01

We provide the first formal foundation of SAND attack trees which are a popular extension of the well-known attack trees. The SAND at- tack tree formalism increases the expressivity of attack trees by intro- ducing the sequential conjunctive operator SAND. This operator enables the modeling of

E2F1 transcription is induced by genotoxic stress through ATM/ATR activation.

Science.gov (United States)

Carcagno, Abel L; Ogara, María F; Sonzogni, Silvina V; Marazita, Mariela C; Sirkin, Pablo F; Ceruti, Julieta M; Cánepa, Eduardo T

2009-05-01

E2F1, a member of the E2F family of transcription factors, plays a critical role in controlling both cell cycle progression and apoptotic cell death in response to DNA damage and oncogene activation. Following genotoxic stresses, E2F1 protein is stabilized by phosphorylation and acetylation driven to its accumulation. The aim of the present work was to examine whether the increase in E2F1 protein levels observed after DNA damage is only a reflection of an increase in E2F1 protein stability or is also the consequence of enhanced transcription of the E2F1 gene. The data presented here demonstrates that UV light and other genotoxics induce the transcription of E2F1 gene in an ATM/ATR dependent manner, which results in increasing E2F1 mRNA and protein levels. After genotoxic stress, transcription of cyclin E, an E2F1 target gene, was significantly induced. This induction was the result of two well-differentiated effects, one of them dependent on de novo protein synthesis and the other on the protein stabilization. Our results strongly support a transcriptional effect of DNA damaging agents on E2F1 expression. The results presented herein uncover a new mechanism involving E2F1 in response to genotoxic stress.

Mutagenic and genotoxic activity of particulate matter MP2,5, in Pamplona, North Santander, Colombia

OpenAIRE

Martínez Montañez, Mónica Liseth; Meléndez Gélvez, Iván; Quijano Parra, Alfonso

2012-01-01

Objective: To study the mutagenic and genotoxic activities of particulate material (MP2,5 collected in Pamplona, Norte de Santander, Colombia.Materials and methods: MP2,5 was monitored by means of a Partisol 2025 sequential air sampler with Plus Palmflex quartz filters. The latter were subjected to two extraction procedures: Soxhlet extraction using dichloromethane-acetone; and ultrasonic extraction using dichloromethane, acetone and dichloromethane/ acetone mix. The mutagenic and genotoxic a...

Heart attack first aid

Science.gov (United States)

First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... A heart attack occurs when the blood flow that carries oxygen to the heart is blocked. The heart muscle ...

Development of a Transgenic Model to Assess Bioavailable Genotoxicity in Sediments

National Research Council Canada - National Science Library

1999-01-01

This technical note describes the rationale for using transgenic animal models to assess the potential genotoxicity of sediments, the benefits that can be obtained using such models versus currently...

Investigating the Possibility to Individualize Asthma Attack Therapy Based on Attack Severity and Patient Characteristics

Directory of Open Access Journals (Sweden)

Sárkány Zoltán

2016-03-01

Full Text Available Introduction: The objective of this study was to investigate with the help of a computerized simulation model whether the treatment of an acute asthma attack can be individualized based on the severity of the attack and the characteristics of the patient. Material and Method: A stochastic lung model was used to simulate the deposition of 1 nm - 10 μm particles during a mild and a moderate asthma attack. Breathing parameters were varied to maximize deposition, and simulation results were compared with those obtained in the case of a severe asthma attack. In order to investigate the effect of height on the deposition of inhaled particles, another series of simulations was carried out with identical breathing parameters, comparing patient heights of 155 cm, 175 cm and 195 cm. Results: The optimization process yielded an increase in the maximum deposition values of around 6-7% for each type of investigated asthma attack, and the difference between attacks of different degree of severity was around 5% for both the initial and the optimized values, a higher degree of obstruction increasing the amount of deposited particles. Conclusions: Our results suggest that the individualization of asthma attack treatment cannot be based on particles of different size, as the highest deposited fraction in all three types of attacks can be obtained using 0.01 μm particles. The use of a specific set of breathing parameters yields a difference between a mild and a moderate, as well as a moderate and a severe asthma attack of around 5%.

Analytical Characterization of Internet Security Attacks

Science.gov (United States)

Sellke, Sarah H.

2010-01-01

Internet security attacks have drawn significant attention due to their enormously adverse impact. These attacks includes Malware (Viruses, Worms, Trojan Horse), Denial of Service, Packet Sniffer, and Password Attacks. There is an increasing need to provide adequate defense mechanisms against these attacks. My thesis proposal deals with analytical…

The cellular receptors of exogenous RNA

Directory of Open Access Journals (Sweden)

Patryk Reniewicz

2016-04-01

Full Text Available One of the key determinants of survival for organisms is proper recognition of exogenous and endogenous nucleic acids. Therefore, high eukaryotes developed a number of receptors that allow for discrimination between friend or foe DNA and RNA. Appearance of exogenous RNA in cytoplasm provides a signal of danger and triggers cellular responses that facilitate eradication of a pathogen. Recognition of exogenous RNA is additionally complicated by fact that large amount of endogenous RNA is present in cytoplasm Thus, number of different receptors, found in eukaryotic cells, is able to recognize that nucleic acid. First group of those receptors consist endosomal Toll like receptors, namely TLR3, TLR7, TLR8 and TLR13. Those receptors recognize RNA released from pathogens that enter the cell by endocytosis. The second group includes cytoplasmic sensors like PKR and the family of RLRs comprised of RIG-I, MDA5 and LGP2. Cytoplasmic receptors recognize RNA from pathogens invading the cell by non-endocytic pathway. In both cases binding of RNA by its receptors results in activation of the signalling cascades that lead to the production of interferon and other cytokines.

Genotoxic and chemopreventive assessment of Cynara scolymus L. aqueous extract in a human-derived liver cell line.

Science.gov (United States)

da Silva, Regiane Pereira; Jacociunas, Laura Vicedo; de Carli, Raíne Fogliati; de Abreu, Bianca Regina Ribas; Lehmann, Mauricio; da Silva, Juliana; Ferraz, Alexandre de Barros Falcão; Dihl, Rafael Rodrigues

2017-10-01

Cynara scolymus L., popularly known as artichoke, is consumed as food and used as tea infusions for pharmacological purposes to treat liver dysfunctions and other conditions. Scientific data on the safety and protective effect of artichoke in human-derived liver cells is missing. This study investigated the genotoxic and modulatory effect of a liophilized extract suspended in water of C. scolymus L. leaves. Four extract concentrations (0.62, 1.25, 2.5 and 5.0 mg/mL) were evaluated using the comet assay on human hepatocyte cultures, HepG2 cells. Genotoxicity was assessed after two treatment periods, 1 and 24 h. Antigenotoxicity was evaluated against oxidative lesions induced by hydrogen peroxide in pre-, simultaneous and post-treatment protocols. Artichoke leaves aqueous extract induced genotoxic effects in HepG2 cells after 1- and 24-h treatments. In turn, extract concentrations of 0.62, 1.25 and 2.5 mg/mL, exhibited a protective effect in pretreatment, compared to hydrogen peroxide alone. However, in simultaneous and post-treatment protocols, only the lowest concentration reduced the frequency of DNA damage induced by hydrogen peroxide. In addition, in the simultaneous treatment protocol, the highest artichoke extract concentration increased hydrogen peroxide genotoxicity. It can be concluded that artichoke is genotoxic, in vitro, to HepG2 cells, but can also modulate hydrogen peroxide DNA damage.

Genotoxic and immunotoxic potential effects of selected psychotropic drugs and antibiotics on blue mussel (Mytilus edulis) hemocytes

International Nuclear Information System (INIS)

Lacaze, Emilie; Pédelucq, Julie; Fortier, Marlène; Brousseau, Pauline; Auffret, Michel; Budzinski, Hélène; Fournier, Michel

2015-01-01

The potential toxicity of pharmaceuticals towards aquatic invertebrates is still poorly understood and sometimes controversial. This study aims to document the in vitro genotoxicity and immunotoxicity of psychotropic drugs and antibiotics on Mytilus edulis. Mussel hemocytes were exposed to fluoxetine, paroxetine, venlafaxine, carbamazepine, sulfamethoxazole, trimethoprim and erythromycin, at concentrations ranging from μg/L to mg/L. Paroxetine at 1.5 μg/L led to DNA damage while the same concentration of venlafaxine caused immunomodulation. Fluoxetine exposure resulted in genotoxicity, immunotoxicity and cytotoxicity. In the case of antibiotics, trimethoprim was genotoxic at 200 μg/L and immunotoxic at 20 mg/L whereas erythromycin elicited same detrimental effects at higher concentrations. DNA metabolism seems to be a highly sensitive target for psychotropic drugs and antibiotics. Furthermore, these compounds affect the immune system of bivalves, with varying intensity. This attests the relevance of these endpoints to assess the toxic mode of action of pharmaceuticals in the aquatic environment. - Highlights: • Psychotropic drugs and antibiotics affect the immune system of Mytilus edulis. • Genotoxic and immunotoxic endpoints were relevant to assess pharmaceuticals toxicity. • DNA metabolism is a highly sensitive target for pharmaceuticals. • Fluoxetine and paroxetine were the most toxic compounds on mussel hemocytes. - Psychotropic drugs and antibiotics have the potential to cause immune toxicity and genotoxicity on Mytilus edulis hemocytes

Genotoxicity of the Musi River (Hyderabad, India) investigated with the VITOTOX test.

Science.gov (United States)

Vijayashree, B; Ahuja, Y R; Regniers, L; Rao, V; Verschaeve, L

2005-01-01

The bacterial VITOTOX genotoxicity test was used to screen water samples collected from three different stations along the banks of the river Musi, in Hyderabad, India. Water was collected at three stations that differed from each other in the nature of the surrounding industrial and other activities. A number of different pollutants were also measured in water, soil and air samples. The three stations were found highly polluted and different with regard to the genotoxicity and toxicity of their samples. These results demonstrate the need for further biological studies in this area to generate valuable data on genomic instability, risk assessment of cancer, and to provide avenues for risk management.

Endogenous versus exogenous generic reference pricing for pharmaceuticals.

Science.gov (United States)

Antoñanzas, F; Juárez-Castelló, C A; Rodríguez-Ibeas, R

2017-12-01

In this paper we carry out a vertical differentiation duopoly model applied to pharmaceutical markets to analyze how endogenous and exogenous generic reference pricing influence competition between generic and branded drugs producers. Unlike the literature, we characterize for the exogenous case the equilibrium prices for all feasible relevant reference prices. Competition is enhanced after the introduction of a reference pricing system. We also compare both reference pricing systems on welfare grounds, assuming two different objective functions for health authorities: (i) standard social welfare and (ii) gross consumer surplus net of total pharmaceutical expenditures. We show that regardless of the objective function, health authorities will never choose endogenous reference pricing. When health authorities are paternalistic, the exogenous reference price that maximizes standard social welfare is such that the price of the generic drug is the reference price while the price of the branded drug is higher than the reference price. When health authorities are not paternalistic, the optimal exogenous reference price is such that the price of the branded drug is the reference price while the price of the generic drug is lower than the reference price.

Anger attacks in obsessive compulsive disorder

Directory of Open Access Journals (Sweden)

Nitesh Prakash Painuly

2011-01-01

Full Text Available Background: Research on anger attacks has been mostly limited to depression, and only a few studies have focused on anger attacks in obsessive compulsive disorder. Materials and Methods: In a cross-sectional study all new obsessive compulsive disorder patients aged 20-60 years attending an outpatient clinic were assessed using the anger attack questionnaire, irritability, depression and anxiety scale (for the direction of the aggressive behavior and quality of life (QOL. Results: The sample consisted of 42 consecutive subjects with obsessive compulsive disorder, out of which 21 (50% had anger attacks. The obsessive compulsive disorder subjects with and without anger attacks did not show significant differences in terms of sociodemographic variables, duration of illness, treatment, and family history. However, subjects with anger attacks had significantly higher prevalence of panic attacks and comorbid depression. Significantly more subjects with anger attacks exhibited aggressive acts toward spouse, parents, children, and other relatives in the form of yelling and threatening to hurt, trying to hurt, and threatening to leave. However, the two groups did not differ significantly in terms of QOL, except for the psychological domain being worse in the subjects with anger attacks. Conclusion: Anger attacks are present in half of the patients with obsessive compulsive disorder, and they correlate with the presence of comorbid depression.

Relationship between genotoxicity and oxidative stress induced by mercury on common carp (Cyprinus carpio) tissues.

Science.gov (United States)

García-Medina, Sandra; Galar-Martínez, Marcela; Gómez-Oliván, Leobardo Manuel; Ruiz-Lara, Karina; Islas-Flores, Hariz; Gasca-Pérez, Eloy

2017-11-01

Mercury is one of the most toxic metals in aquatic systems since it is able to induce neurobehavioral disorders as well as renal and gastrointestinal tract damage. The common carp Cyprinus carpio is an important species from both an ecological and economic viewpoint as it is consumed in many countries, the top producers being Mexico, China, India and Japan. The present study aimed to evaluate the relation between Hg-induced oxidative stress and genotoxicity in diverse tissues of C. carpio. Specimens were exposed to 0.01mgHg/L (the maximum permissible limit for aquatic life protection), and lipid peroxidation, protein carbonyl content and the activity of antioxidant enzymes were evaluated at 96h. Micronuclei frequency and DNA damage by comet assay were determined at 12, 24, 48, 72 and 96h. Hg induced oxidative stress and genotoxicity on exposed fish, since inhibition of antioxidant enzymes activity and increases in lipid peroxidation, DNA damage and micronuclei frequency occurred. Blood, gill and liver were more susceptible to oxidative stress, while blood were more sensitive to genotoxicity. In conclusion, Hg at concentrations equal to the maximum permissible limit for aquatic life protection induced oxidative stress and genotoxicity on C. carpio, and these two effects prove to be correlated. Copyright © 2017 Elsevier B.V. All rights reserved.

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers.

Science.gov (United States)

Shaikh, Amrin; Barot, Darshana; Chandel, Divya

2018-04-01

Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals. To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers. The study groups included 70 petrol pump workers (exposed group) and 70 healthy age-matched individuals with no known exposure (comparison group). Buccal micronucleus cytome assay (BMCyt) was performed to check the genotoxicity caused due to inhalation of gasoline fumes. The frequencies of micronucleated cells, nuclear bud, condensed chromatin cells, karyorrhectic cells, pyknotic cells, and karyolytic cells were significantly higher in the exposed workers compared to the comparison group. Exposure to gasoline fumes is associated with increased frequency of cell abnormalities. This may lead to various health consequences including cancer in those occupationally exposed to gasoline fumes.

Potential genotoxicity of traditional chinese medicinal plants and phytochemicals: an overview.

Science.gov (United States)

Zhou, Jue; Ouedraogo, Moustapha; Qu, Fan; Duez, Pierre

2013-12-01

In the last decades, cases of poisoning due to herbal medicines have occurred in many countries; Chinese herbal medicines (CHMs) are occasionally involved. The experience gained from traditional use is efficient to detect immediate or near-immediate relationship between administration and toxic effects but is quite unlikely to detect medium- to long-term toxicities; thorough investigations of herbal medicines (toxicity assessments, active pharmacovigilance) appear then essential for their safe use. Genotoxicity is an especially insidious toxicity that may result in carcinoma development years after exposure; it can arise from multiple compounds, with or without metabolic activation. The present work reviews traditional CHMs and phytochemicals that have been shown to present a genotoxic hazard. Copyright © 2013 John Wiley & Sons, Ltd.

Quantitative structure-activity relationships for toxicity and genotoxicity of halogenated aliphatic compounds: wing spot test of Drosophila melanogaster.

Science.gov (United States)

Chroust, Karel; Pavlová, Martina; Prokop, Zbynek; Mendel, Jan; Bozková, Katerina; Kubát, Zdenek; Zajícková, Veronika; Damborský, Jiri

2007-02-01

Halogenated aliphatic compounds were evaluated for toxic and genotoxic effects in the somatic mutation and recombination test employing Drosophila melanogaster. The tested chemicals included chlorinated, brominated and iodinated; mono-, di- and tri-substituted; saturated and unsaturated alkanes: 1,2-dibromoethane, 1-bromo-2-chloroethane, 1-iodopropane, 2,3-dichloropropene, 3-bromo-1-propene, epibromohydrin, 2-iodobutane, 3-chloro-2-methylpropene, 1,2,3-trichloropropane, 1,2-dichloroethane, 1,2-dichlorobutane, 1-chloro-2-methylpropane, 1,3-dichloropropane, 1,2-dichloropropane, 2-chloroethymethylether, 1-bromo-2-methylpropane and 1-chloropentane. N-methyl-N-nitrosourea served as the positive and distilled water as the negative control. The set of chemicals for the toxicological testing was selected by the use of statistical experiment design. Group of unsaturated aliphatic hydrocarbons were generally more toxic than saturated analogues. The genotoxic effect was observed with 14 compounds in the wing spot test, while 3 substances did not show any genotoxicity by using the wing spot test at 50% lethal concentration. The highest number of wing spots was observed in genotoxicity assay with 1-bromo-2-chloroethane, 1,2-dichloroethane, 1,2-dibromoethane and 1-iodopropane. Nucleophilic superdelocalizability calculated by quantum mechanics appears to be a good parameter for prediction of both toxicity and genotoxicity effects of halogenated aliphatic compounds.

Induced effect of irradiated exogenous DNA on wheat

International Nuclear Information System (INIS)

Li Zhongjie; Sun Guangzu; Wang Guangjin

1996-01-01

Irradiated exogenous DNA introduced into wheat can give rise to break of DNA-chain and damage of part of alkali radicals. Introducing exogenous DNA irradiated by γ rays could increase Do fructification rate and decrease seed size and plumpness. These tendencies became obvious with dose increase. In comparison with control DNA, introducing DNA irradiated could raise evidently mutagenic effect of pollen tube pathway technique

Effect of a base-catalyzed dechlorination process on the genotoxicity of PCB-contaminated soil

Energy Technology Data Exchange (ETDEWEB)

DeMarini, D.M.; Houk, V.S.; Kornel, A.; Rogers, C.J.

1992-01-01

We evaluated the genotoxicity of dichloromethane (DCM) extracts of PCB-contaminated soil before and after the soil had been treated by a base-catalyzed dechlorination process, which involved heating a mixture of the soil, polyethylene glycol, and sodium hydroxide to 250-350 C. This dechlorination process reduced by over 99% the PCB concentration in the soil, which was initially 2,200 ppm. The DCM extracts of both control and treated soils were not mutagenic in strain TA100 of Salmonella, but they were mutagenic in strain TA98. The base-catalyzed dechlorination process reduced the mutagenic potency of the soil by approximately one-half. The DCM extracts of the soils before and after treatment were equally genotoxic in a prophage-induction assay in E. coli, which detects some chlorinated organic carcinogens that were not detected by the Salmonella mutagenicity assay. These results show that treatment of PCB-contaminated soil by this base-catalyzed dechlorination process did not increase the genotoxicity of the soil.

Seven Deadliest Social Network Attacks

CERN Document Server

Timm, Carl

2010-01-01

Do you need to keep up with the latest hacks, attacks, and exploits effecting social networks? Then you need Seven Deadliest Social Network Attacks. This book pinpoints the most dangerous hacks and exploits specific to social networks like Facebook, Twitter, and MySpace, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks detailed in this book include: Social Networking Infrastruct

Acute toxicity and genotoxicity of fermented traditional medicine oyaksungi-san

Directory of Open Access Journals (Sweden)

Hwayong Park

2017-06-01

Conclusion: As a whole, no acute toxicity or genotoxicity were observed in all the assays examined. Therefore, fermented OY is considered to be a safe material that can be used for development of complementary and alternative medicine using bioconversion.

Pericarditis - after heart attack

Science.gov (United States)

... include: A previous heart attack Open heart surgery Chest trauma A heart attack that has affected the thickness of your heart muscle Symptoms Symptoms include: Anxiety Chest pain from the swollen pericardium rubbing on the ...

Potential genotoxic effects of melted snow from an urban area revealed by the Allium cepa test.

Science.gov (United States)

Blagojević, Jelena; Stamenković, Gorana; Vujosević, Mladen

2009-09-01

The presence of well-known atmospheric pollutants is regularly screened for in large towns but knowledge about the effects of mixtures of different pollutants and especially their genotoxic potential is largely missing. Since falling snow collects pollutants from the air, melted snow samples could be suitable for evaluating potential genotoxicity. For this purpose the Allium cepa anaphase-telophase test was used to analyse melted snow samples from Belgrade, the capital city of Serbia. Samples of snow were taken at two sites, characterized by differences in pollution intensity, in three successive years. At the more polluted site the analyses showed a very high degree of both toxicity and genotoxicity in the first year of the study corresponding to the effects of the known mutagen used as the positive control. At the other site the situation was much better but not without warning signals. The results showed that standard analyses for the presence of certain contaminants in the air do not give an accurate picture of the possible consequences of urban air pollution because the genotoxic potential remains hidden. The A. cepa test has been demonstrated to be very convenient for evaluation of air pollution through analyses of melted snow samples.

In vivo genotoxicity assessment in rats exposed to Prestige-like oil by inhalation.

Science.gov (United States)

Valdiglesias, Vanessa; Kiliç, Gözde; Costa, Carla; Amor-Carro, Óscar; Mariñas-Pardo, Luis; Ramos-Barbón, David; Méndez, Josefina; Pásaro, Eduardo; Laffon, Blanca

2012-01-01

One of the largest oil spill disasters in recent times was the accident of the oil tanker Prestige in front of the Galician coast in 2002. Thousands of people participated in the cleanup of the contaminated areas, being exposed to a complex mixture of toxic substances. Acute and prolonged respiratory symptoms and genotoxic effects were reported, although environmental exposure measurements were restricted to current determinations, such that attribution of effects observed to oil exposure is difficult to establish. The aim of this study was to analyze peripheral blood leukocytes (PBL) harvested from a rat model of subchronic exposure to a fuel oil with similar characteristics to that spilled by the Prestige tanker, in order to determine potential genotoxic effects under strictly controlled, in vivo exposure. Wistar Han and Brown Norway rats were exposed to the oil for 3 wk, and micronucleus test (MN) and comet assay, standard and modified with 8-oxoguanine DNA glycosylase (OGG1) enzyme, were employed to assess genotoxicity 72 h and 15 d after the last exposure. In addition, the potential effects of oil exposure on DNA repair capacity were determined by means of mutagen sensitivity assay. Results obtained from this study showed that inhalation oil exposure induced DNA damage in both Brown Norway and Wistar Han rats, especially in those animals evaluated 15 d after exposure. Although alterations in the DNA repair responses were noted, the sensitivity to oil substances varied depending on rat strain. Data support previous positive genotoxicity results reported in humans exposed to Prestige oil during cleanup tasks.

Genotoxic effects of environmental endocrine disruptors on the aquatic insect Chironomus riparius evaluated using the comet assay.

Science.gov (United States)

Martínez-Paz, Pedro; Morales, Mónica; Martínez-Guitarte, José Luis; Morcillo, Gloria

2013-12-12

Genotoxicity is one of the most important toxic endpoints in chemical toxicity testing and environmental risk assessment. The aim of this study was to evaluate the genotoxic potential of various environmental pollutants frequently found in aquatic environments and characterized by their endocrine disrupting activity. Monitoring of DNA damage was undertaken after in vivo exposures of the aquatic larvae of the midge Chironomus riparius, a model organism that represents an abundant and ecologically relevant macroinvertebrate, widely used in freshwater toxicology. DNA-induced damage, resulting in DNA fragmentation, was quantified by the comet assay after short (24 h) and long (96 h) exposures to different concentrations of the selected toxicants: bisphenol A (BPA), nonylphenol (NP), pentachlorophenol (PCP), tributyltin (TBT) and triclosan (TCS). All five compounds were found to have genotoxic activity as demonstrated by significant increases in all the comet parameters (%DNA in tail, tail length, tail moment and Olive tail moment) at all tested concentrations. Persistent exposure did not increase the extent of DNA damage, except for TCS at the highest concentration, but generally there was a reduction in DNA damage thought to be associated with the induction of the detoxification processes and repairing mechanisms. Comparative analysis showed differences in the genotoxic potential between the chemicals, as well as significant time and concentration-dependent variations, which most likely reflect differences in the ability to repair DNA damage under the different treatments. The present report demonstrates the sensitivity of the benthic larvae of C. riparius to these environmental genotoxins suggesting its potential as biomonitor organism in freshwater ecosystems. The results obtained about the DNA-damaging potential of these environmental pollutants reinforce the need for additional studies on the genotoxicity of endocrine active substances that, by linking genotoxic

Lack of genotoxicity in medical oncology nurses handling antineoplastic drugs: effect of work environment and protective equipment.

Science.gov (United States)

Gulten, Tuna; Evke, Elif; Ercan, Ilker; Evrensel, Turkkan; Kurt, Ender; Manavoglu, Osman

2011-01-01

In this study we aimed to investigate the genotoxic effects of antineoplastic agents in occupationally exposed oncology nurses. Genotoxic effects mean the disruptive effects in the integrity of DNA and they are associated with cancer development. Biomonitoring of health care workers handling antineoplastic agents is helpful for the evaluation of exposure to cytostatics. The study included an exposed and two control groups. The exposed group (n=9) was comprised of oncology nurses. The first (n=9) and second (n=10) control groups were comprised of subjects who did not come into contact with antineoplastic drugs working respectively in the same department with oncology nurses and in different departments. Genotoxicity evaluation was performed using SCE analysis. After applying culture, harvest and chromosome staining procedures, a total of 25 metaphases were analyzed per person. Kruskal Wallis test was used to perform statistical analysis. A statistically significant difference of sister chromatid exchange frequencies was not observed between the exposed and control groups. Lack of genotoxicity in medical oncology nurses might be due to good working conditions with high standards of technical equipment and improved personal protection.

WILD PIG ATTACKS ON HUMANS

Energy Technology Data Exchange (ETDEWEB)

Mayer, J.

2013-04-12

Attacks on humans by wild pigs (Sus scrofa) have been documented since ancient times. However, studies characterizing these incidents are lacking. In an effort to better understand this phenomenon, information was collected from 412 wild pig attacks on humans. Similar to studies of large predator attacks on humans, data came from a variety of sources. The various attacks compiled occurred in seven zoogeographic realms. Most attacks occurred within the species native range, and specifically in rural areas. The occurrence was highest during the winter months and daylight hours. Most happened under non-hunting circumstances and appeared to be unprovoked. Wounded animals were the chief cause of these attacks in hunting situations. The animals involved were typically solitary, male and large in size. The fate of the wild pigs involved in these attacks varied depending upon the circumstances, however, most escaped uninjured. Most human victims were adult males traveling on foot and alone. The most frequent outcome for these victims was physical contact/mauling. The severity of resulting injuries ranged from minor to fatal. Most of the mauled victims had injuries to only one part of their bodies, with legs/feet being the most frequent body part injured. Injuries were primarily in the form of lacerations and punctures. Fatalities were typically due to blood loss. In some cases, serious infections or toxemia resulted from the injuries. Other species (i.e., pets and livestock) were also accompanying some of the humans during these attacks. The fates of these animals varied from escaping uninjured to being killed. Frequency data on both non-hunting and hunting incidents of wild pig attacks on humans at the Savannah River Site, South Carolina, showed quantitatively that such incidents are rare.

Titanium dioxide nanoparticles cause genotoxicity in human lung epithelial cells

Science.gov (United States)

The use of engineered nanoparticles in consumer products is steadily increasing. However, the health effects of exposure to these nanoparticles are not thoroughly understood. This study investigated the genotoxicity of six titanium dioxide and two cerium oxide nanoparticles of va...

Cache timing attacks on recent microarchitectures

DEFF Research Database (Denmark)

Andreou, Alexandres; Bogdanov, Andrey; Tischhauser, Elmar Wolfgang

2017-01-01

Cache timing attacks have been known for a long time, however since the rise of cloud computing and shared hardware resources, such attacks found new potentially devastating applications. One prominent example is S$A (presented by Irazoqui et al at S&P 2015) which is a cache timing attack against...... AES or similar algorithms in virtualized environments. This paper applies variants of this cache timing attack to Intel's latest generation of microprocessors. It enables a spy-process to recover cryptographic keys, interacting with the victim processes only over TCP. The threat model is a logically...... separated but CPU co-located attacker with root privileges. We report successful and practically verified applications of this attack against a wide range of microarchitectures, from a two-core Nehalem processor (i5-650) to two-core Haswell (i7-4600M) and four-core Skylake processors (i7-6700). The attack...

Assessment of Health Effects of Exogenous Urea: Summary and Key Findings.

Science.gov (United States)

Dickerson, Aisha S; Lee, Janice S; Keshava, Channa; Hotchkiss, Andrew; Persad, Amanda S

2018-05-01

Urea has been utilized as a reductant in diesel fuels to lower emission of nitrogen oxides, igniting interest in probable human health hazards associated with exposure to exogenous urea. Here, we summarize and update key findings on potential health effects of exogenous urea, including carcinogenicity. No definitive target organs for oral exposure were identified; however, results in animal studies suggest that the liver and kidney could be potential target organs of urea toxicity. The available human-subject literature suggests that the impact on lung function is minimal. Based on the literature on exogenous urea, we concluded that there was inadequate information to assess the carcinogenic potential of urea, or perform a quantitative assessment to derive reference values. Given the limited information on exogenous urea, additional research to address gaps for exogenous urea should include long-term cancer bioassays, two-generation reproductive toxicity studies, and mode-of-action investigations.

Exogenous (automatic) attention to emotional stimuli: a review

OpenAIRE

Carretié, Luis

2014-01-01

Current knowledge on the architecture of exogenous attention (also called automatic, bottom-up, or stimulus-driven attention, among other terms) has been mainly obtained from studies employing neutral, anodyne stimuli. Since, from an evolutionary perspective, exogenous attention can be understood as an adaptive tool for rapidly detecting salient events, reorienting processing resources to them, and enhancing processing mechanisms, emotional events (which are, by definition, salient for the in...

The yeast mitogen-activated protein kinase Slt2 is involved in the cellular response to genotoxic stress

Directory of Open Access Journals (Sweden)

Soriano-Carot María

2012-02-01

Full Text Available Abstract Background The maintenance of genomic integrity is essential for cell viability. Complex signalling pathways (DNA integrity checkpoints mediate the response to genotoxic stresses. Identifying new functions involved in the cellular response to DNA-damage is crucial. The Saccharomyces cerevisiae SLT2 gene encodes a member of the mitogen-activated protein kinase (MAPK cascade whose main function is the maintenance of the cell wall integrity. However, different observations suggest that SLT2 may also have a role related to DNA metabolism. Results This work consisted in a comprehensive study to connect the Slt2 protein to genome integrity maintenance in response to genotoxic stresses. The slt2 mutant strain was hypersensitive to a variety of genotoxic treatments, including incubation with hydroxyurea (HU, methylmetanosulfonate (MMS, phleomycin or UV irradiation. Furthermore, Slt2 was activated by all these treatments, which suggests that Slt2 plays a central role in the cellular response to genotoxic stresses. Activation of Slt2 was not dependent on the DNA integrity checkpoint. For MMS and UV, Slt2 activation required progression through the cell cycle. In contrast, HU also activated Slt2 in nocodazol-arrested cells, which suggests that Slt2 may respond to dNTP pools alterations. However, neither the protein level of the distinct ribonucleotide reductase subunits nor the dNTP pools were affected in a slt2 mutant strain. An analysis of the checkpoint function revealed that Slt2 was not required for either cell cycle arrest or the activation of the Rad53 checkpoint kinase in response to DNA damage. However, slt2 mutant cells showed an elongated bud and partially impaired Swe1 degradation after replicative stress, indicating that Slt2 could contribute, in parallel with Rad53, to bud morphogenesis control after genotoxic stresses. Conclusions Slt2 is activated by several genotoxic treatments and is required to properly cope with DNA damage. Slt

Cytotoxicity and genotoxicity of calcium silicate-based cements on an osteoblast lineage

Directory of Open Access Journals (Sweden)

Ana Lívia GOMES-CORNÉLIO

2016-01-01

Full Text Available Abstract Several calcium silicate-based biomaterials have been developed in recent years, in addition to Mineral Trioxide Aggregate (MTA. The aim of this study was to evaluate the cytotoxicity, genotoxicity and apoptosis/necrosis in human osteoblast cells (SAOS-2 of pure calcium silicate-based cements (CSC and modified formulations: modified calcium silicate-based cements (CSCM and three resin-based calcium silicate cements (CSCR1 (CSCR 2 (CSCR3. The following tests were performed after 24 hours of cement extract exposure: methyl-thiazolyl tetrazolium (MTT, apoptosis/necrosis assay and comet assay. The negative control (CT- was performed with untreated cells, and the positive control (CT+ used hydrogen peroxide. The data for MTT and apoptosis were submitted to analysis of variance and Bonferroni’s posttest (p < 0.05, and the data for the comet assay analysis, to the Kruskal-Wallis and Dunn tests (p < 0.05. The MTT test showed no significant difference among the materials in 2 mg/mL and 10 mg/mL concentrations. CSCR3 showed lower cell viability at 10 mg/mL. Only CSC showed lower cell viability at 50 mg/mL. CSCR1, CSCR2 and CSCR3 showed a higher percentage of initial apoptosis than the control in the apoptosis test, after 24 hours exposure. The same cements showed no genotoxicity in the concentration of 2 mg/mL, with the comet assay. CSC and CSCR2 were also not genotoxic at 10 mg/mL. All experimental materials showed viability with MTT. CSC and CSCR2 presented a better response to apoptosis and genotoxicity evaluation in the 10 mg/mL concentration, and demonstrated a considerable potential for use as reparative materials.

The Cyber-Physical Attacker

DEFF Research Database (Denmark)

Vigo, Roberto

2012-01-01

The world of Cyber-Physical Systems ranges from industrial to national interest applications. Even though these systems are pervading our everyday life, we are still far from fully understanding their security properties. Devising a suitable attacker model is a crucial element when studying...... the security properties of CPSs, as a system cannot be secured without defining the threats it is subject to. In this work an attacker scenario is presented which addresses the peculiarities of a cyber-physical adversary, and we discuss how this scenario relates to other attacker models popular in the security...

Forensics Investigation of Web Application Security Attacks

OpenAIRE

Amor Lazzez; Thabet Slimani

2015-01-01

Nowadays, web applications are popular targets for security attackers. Using specific security mechanisms, we can prevent or detect a security attack on a web application, but we cannot find out the criminal who has carried out the security attack. Being unable to trace back an attack, encourages hackers to launch new attacks on the same system. Web application forensics aims to trace back and attribute a web application security attack to its originator. This may significantly reduce the sec...

Effect Of Exogenous Progesterone On Blood Chemistry Of Large ...

African Journals Online (AJOL)

Exogenous hormones are major economic factors in swine production. This study evaluate the effects of exogenous administration of progesterone on the blood chemistry of pigs.Experiment involved weekly injections of progesterone to 24 pigs (12 males and 12 females)from day old to 24 weeks and only corn oil to another ...

Detection of genotoxic effects of drinking water disinfection by-products using Vicia faba bioassay.

Science.gov (United States)

Hu, Yu; Tan, Li; Zhang, Shao-Hui; Zuo, Yu-Ting; Han, Xue; Liu, Na; Lu, Wen-Qing; Liu, Ai-Lin

2017-01-01

Plant-based bioassays have gained wide use among the toxicological and/or ecotoxicological assessment procedures because of their simplicity, sensitivity, low cost, and reliability. The present study describes the use of Vicia faba (V. faba) micronucleus (MN) test and V. faba comet assay in the evaluation of the genotoxic potential of disinfection by-products (DBPs) commonly found in chlorine-disinfected drinking water. Five haloacetic acids and three halogenated acetonitriles were chosen as representatives of DBPs in this study because they are of potentially great public health risk. Results of the MN test indicated that monochloroacetic acid (MCA), monobromoacetic acid (MBA), dichloroacetic acid (DCA), dibromoacetic acid (DBA), trichloroacetic acid (TCA), and trichloroacetonitrile (TCAN) caused a statistically significant increase in MN frequency in V. faba root tip cells. However, no genotoxic response was observed for dichloroacetonitrile (DCAN) and dibromoacetonitrile (DBAN). Results of the comet assay showed that all tested DBPs induced a statistically significant increase in genomic DNA damage to V. faba root tip cells. On considering the capacity to detect genomic damage of a different nature, we suggest that a combination of V. faba MN test and V. faba comet assay is a useful tool for the detection of genotoxic effects of DBPs. It is worthy of assessing the feasibility of using V. faba comet assay combined with V. faba MN test to screen for the genotoxic activity of chlorinated drinking water in future work.

Chlorination of tramadol: Reaction kinetics, mechanism and genotoxicity evaluation.

Science.gov (United States)

Cheng, Hanyang; Song, Dean; Chang, Yangyang; Liu, Huijuan; Qu, Jiuhui

2015-12-01

Tramadol (TRA) is one of the most detected analgesics in environmental matrices, and it is of high significance to study the reactivity of TRA during chlorination considering its potential toxicity to the environment. The chlorine/TRA reaction is first order with respect to the TRA concentration, and a combination of first-order and second-order with respect to chlorine concentration. The pH dependence of the observed rate constants (kobs) showed that the TRA oxidation reactivity increased with increasing pH. kobs can be quantitatively described by considering all active species including Cl2, Cl2O and HOCl, and the individual rate constants of HOCl/TRA(0), HOCl/TRAH(+), Cl2/TRA and Cl2O/TRA reactions were calculated to be (2.61±0.29)×10(3)M(-1)s(-1), 14.73±4.17M(-1)s(-1), (3.93±0.34)×10(5)M(-1)s(-1) and (5.66±1.83)×10(6)M(-1)s(-1), respectively. Eleven degradation products were detected with UPLC-Q-TOF-MS, and the corresponding structures of eight products found under various pH conditions were proposed. The amine group was proposed to be the initial attack site under alkaline pH conditions, where reaction of the deprotonated amine group with HOCl is favorable. Under acidic and neutral pH conditions, however, two possible reaction pathways were proposed. One is an electrophilic substitution on the aromatic ring, and another is an electrophilic substitution on the nitrogen, leading to an N-chlorinated intermediate, which can be further oxidized. Finally, the SOS/umu test showed that the genotoxicity of TRA chlorination products increased with increasing dosage of chlorine, which was mostly attributed to the formation of some chlorine substitution products. Copyright © 2015 Elsevier Ltd. All rights reserved.

Adaptive cyber-attack modeling system

Science.gov (United States)

Gonsalves, Paul G.; Dougherty, Edward T.

2006-05-01

The pervasiveness of software and networked information systems is evident across a broad spectrum of business and government sectors. Such reliance provides an ample opportunity not only for the nefarious exploits of lone wolf computer hackers, but for more systematic software attacks from organized entities. Much effort and focus has been placed on preventing and ameliorating network and OS attacks, a concomitant emphasis is required to address protection of mission critical software. Typical software protection technique and methodology evaluation and verification and validation (V&V) involves the use of a team of subject matter experts (SMEs) to mimic potential attackers or hackers. This manpower intensive, time-consuming, and potentially cost-prohibitive approach is not amenable to performing the necessary multiple non-subjective analyses required to support quantifying software protection levels. To facilitate the evaluation and V&V of software protection solutions, we have designed and developed a prototype adaptive cyber attack modeling system. Our approach integrates an off-line mechanism for rapid construction of Bayesian belief network (BN) attack models with an on-line model instantiation, adaptation and knowledge acquisition scheme. Off-line model construction is supported via a knowledge elicitation approach for identifying key domain requirements and a process for translating these requirements into a library of BN-based cyber-attack models. On-line attack modeling and knowledge acquisition is supported via BN evidence propagation and model parameter learning.

Predicting Factors of Zone 4 Attack in Volleyball.

Science.gov (United States)

Costa, Gustavo C; Castro, Henrique O; Evangelista, Breno F; Malheiros, Laura M; Greco, Pablo J; Ugrinowitsch, Herbert

2017-06-01

This study examined 142 volleyball games of the Men's Super League 2014/2015 seasons in Brazil from which we analyzed 24-26 games of each participating team, identifying 5,267 Zone 4 attacks for further analysis. Within these Zone 4 attacks, we analyzed the association between the effect of the attack carried out and the separate effects of serve reception, tempo and type of attack. We found that the reception, tempo of attack, second tempo of attack, and power of diagonal attack were predictors of the attack effect in Zone 4. Moreover, placed attacks showed a tendency to not yield a score. In conclusion, winning points in high-level men's volleyball requires excellent receptions, a fast attack tempo and powerfully executed of attacks.

Exogenous and endogenous spatial attention effects on visuospatial working memory.

Science.gov (United States)

Botta, Fabiano; Santangelo, Valerio; Raffone, Antonino; Lupiáñez, Juan; Belardinelli, Marta Olivetti

2010-08-01

In this study, we investigate how exogenous and endogenous orienting of spatial attention affect visuospatial working memory (VSWM). Specifically, we focused on two attentional effects and their consequences on storage in VSWM, when exogenous (Experiment 1) or endogenous (Experiment 2) orienting cues were used. The first effect, known as the meridian effect, is given by a decrement in behavioural performance when spatial cues and targets are presented in locations separated by vertical and/or horizontal meridians. The second effect, known as the distance effect, is given by a decrement in the orienting effects as a function of the spatial distance between cues and targets. Our results revealed a dissociation between exogenous and endogenous orienting mechanisms in terms of both meridian and distance effects. We found that meridian crossing affects performance only when endogenous cues were used. Specifically, VSWM performance with endogenous cueing depended more on the number of meridian crossings than on distance between cue and target. By contrast, a U-shaped distance dependency was observed using exogenous cues. Our findings therefore suggest that exogenous and endogenous orienting mechanisms lead to different forms of attentional bias for storage in VSWM.

Exogenous ethylene inhibits sprout growth in onion bulbs.

Science.gov (United States)

Bufler, Gebhard

2009-01-01

Exogenous ethylene has recently gained commercial interest as a sprouting inhibitor of onion bulbs. The role of ethylene in dormancy and sprouting of onions, however, is not known. A cultivar (Allium cepa 'Copra') with a true period of dormancy was used. Dormant and sprouting states of onion bulbs were treated with supposedly saturating doses of ethylene or with the ethylene-action inhibitor 1-methylcyclopropene (1-MCP). Initial sprouting was determined during storage at 18 degrees C by monitoring leaf blade elongation in a specific size class of leaf sheaths. Changes in ATP content and sucrose synthase activity in the sprout leaves, indicators of the sprouting state, were determined. CO(2) and ethylene production of onion bulbs during storage were recorded. Exogenous ethylene suppressed sprout growth of both dormant and already sprouting onion bulbs by inhibiting leaf blade elongation. In contrast to this growth-inhibiting effect, ethylene stimulated CO(2) production by the bulbs about 2-fold. The duration of dormancy was not significantly affected by exogenous ethylene. However, treatment of dormant bulbs with 1-MCP caused premature sprouting. Exogenous ethylene proved to be a powerful inhibitor of sprout growth in onion bulbs. The dormancy breaking effect of 1-MCP indicates a regulatory role of endogenous ethylene in onion bulb dormancy.

Attack Potential Evaluation in Desktop and Smartphone Fingerprint Sensors: Can They Be Attacked by Anyone?

Directory of Open Access Journals (Sweden)

Ines Goicoechea-Telleria

2018-01-01

Full Text Available The use of biometrics keeps growing. Every day, we use biometric recognition to unlock our phones or to have access to places such as the gym or the office, so we rely on the security manufacturers offer when protecting our privileges and private life. It is well known that it is possible to hack into a fingerprint sensor using fake fingers made of Play-Doh and other easy-to-obtain materials but to what extent? Is this true for all users or only for specialists with a deep knowledge on biometrics? Are smartphone fingerprint sensors as reliable as desktop sensors? To answer these questions, we performed 3 separate evaluations. First, we evaluated 4 desktop fingerprint sensors of different technologies by attacking them with 7 different fake finger materials. All of them were successfully attacked by an experienced attacker. Secondly, we carried out a similar test on 5 smartphones with embedded sensors using the most successful materials, which also hacked the 5 sensors. Lastly, we gathered 15 simulated attackers with no background in biometrics to create fake fingers of several materials, and they had one week to attack the fingerprint sensors of the same 5 smartphones, with the starting point of a short video with the techniques to create them. All 5 smartphones were successfully attacked by an inexperienced attacker. This paper will provide the results achieved, as well as an analysis on the attack potential of every case. All results are given following the metrics of the standard ISO/IEC 30107-3.

Genotoxicity of Nicotiana tabacum leaves on Helix aspersa.

Science.gov (United States)

da Silva, Fernanda R; Erdtmann, Bernardo; Dalpiaz, Tiago; Nunes, Emilene; Ferraz, Alexandre; Martins, Tales L C; Dias, Johny F; da Rosa, Darlan P; Porawskie, Marilene; Bona, Silvia; da Silva, Juliana

2013-07-01

Tobacco farmers are routinely exposed to complex mixtures of inorganic and organic chemicals present in tobacco leaves. In this study, we examined the genotoxicity of tobacco leaves in the snail Helix aspersa as a measure of the risk to human health. DNA damage was evaluated using the micronucleus test and the Comet assay and the concentration of cytochrome P450 enzymes was estimated. Two groups of snails were studied: one fed on tobacco leaves and one fed on lettuce (Lactuca sativa L) leaves (control group). All of the snails received leaves (tobacco and lettuce leaves were the only food provided) and water ad libitum. Hemolymph cells were collected after 0, 24, 48 and 72 h. The Comet assay and micronucleus test showed that exposure to tobacco leaves for different periods of time caused significant DNA damage. Inhibition of cytochrome P450 enzymes occurred only in the tobacco group. Chemical analysis indicated the presence of the alkaloid nicotine, coumarins, saponins, flavonoids and various metals. These results show that tobacco leaves are genotoxic in H. aspersa and inhibit cytochrome P450 activity, probably through the action of the complex chemical mixture present in the plant.

Genotoxicity of Nicotiana tabacum leaves on Helix aspersa

Directory of Open Access Journals (Sweden)

Fernanda R. da Silva

2013-01-01

Full Text Available Tobacco farmers are routinely exposed to complex mixtures of inorganic and organic chemicals present in tobacco leaves. In this study, we examined the genotoxicity of tobacco leaves in the snail Helix aspersa as a measure of the risk to human health. DNA damage was evaluated using the micronucleus test and the Comet assay and the concentration of cytochrome P450 enzymes was estimated. Two groups of snails were studied: one fed on tobacco leaves and one fed on lettuce (Lactuca sativa L leaves (control group. All of the snails received leaves (tobacco and lettuce leaves were the only food provided and water ad libitum. Hemolymph cells were collected after 0, 24, 48 and 72 h. The Comet assay and micronucleus test showed that exposure to tobacco leaves for different periods of time caused significant DNA damage. Inhibition of cytochrome P450 enzymes occurred only in the tobacco group. Chemical analysis indicated the presence of the alkaloid nicotine, coumarins, saponins, flavonoids and various metals. These results show that tobacco leaves are genotoxic in H. aspersa and inhibit cytochrome P450 activity, probably through the action of the complex chemical mixture present in the plant.

Measurement of DNA strand breaks as a biomarker of genotoxic pollutants

Digital Repository Service at National Institute of Oceanography (India)

Sarkar, A.; Patil, S.S.; Holkar, P.K.R.

This paper deals with the development of a molecular biomarker technique by measurement of DNA integrity in marine organisms for biomonitoring of pollution due to genotoxic compounds. The marine environment is continuously being polluted...

Spatial orienting around the fovea: exogenous and endogenous cueing effects.

Science.gov (United States)

Yang, Taoxi; Zhang, Jiyuan; Bao, Yan

2015-09-01

The effect of covert attention in perifoveal and peripheral locations has been studied extensively. However, it is less clear whether attention operates similarly in the foveal area itself. The present study aims to investigate whether the attentional orienting elicited by an exogenous or endogenous cue can operate within the foveal area and whether attentional orienting operates similarly between foveal and perifoveal regions. By manipulating exogenous orienting in Experiment 1 and endogenous orienting in Experiment 2, we observed both forms of cueing in the foveal area. Specifically, we observed a larger exogenous cue-induced inhibitory effect (i.e., inhibition of return effect) and a similar endogenous cue-elicited facilitatory effect for the perifoveal relative to the foveal targets. We conclude that exogenous and endogenous orienting subject to two independent attentional systems with distinct modulation patterns in the foveal area.

Exogenous insulin antibody syndrome (EIAS): a clinical syndrome associated with insulin antibodies induced by exogenous insulin in diabetic patients.

Science.gov (United States)

Hu, Xiaolei; Chen, Fengling

2018-01-01

Insulin has been used for diabetes therapy and has achieved significant therapeutic effect. In recent years, the use of purified and recombinant human insulin preparations has markedly reduced, but not completely suppressed, the incidence of insulin antibodies (IAs). IAs induced by exogenous insulin in diabetic patients is associated with clinical events, which is named exogenous insulin antibody syndrome (EIAS). The present review is based on our research and summarizes the characterization of IAs, the factors affecting IA development, the clinical significance of IAs and the treatments for EIAS. © 2018 The authors.

[Farmer's lung--a form of exogenous allergic alveolitis].

Science.gov (United States)

Sambale, M; Liebetrau, G

1990-11-15

Exogenic allergic alveolitides are caused by organic dusts which contain bacteria, moulds or vegetable and animal antigens. The farmer's lung as a form of the exogenic allergic alveolitis is a rare disease. The uncharacteristic symptomatology in the initial phase and in particular the retarded beginning of the symptom after several hours handicap the timely recognition in an early phase of the disease so that curative therapeutic measures are rarely possible. The cases of the disease are found only at the chronic stage, at the stage of the pulmonary fibrosis. Then the prognosis is unfavourable. In the Central Clinic for Heart and Lung Diseases Bad Berka 1,110 patients with alveolitides and lung fibroses were diagnosed in the period from 1975 to 1988. 306 of them could be clarified as exogenic allergic alveolitis, 61 of them (19.8%) were farmer's lungs.

Managing burn victims of suicide bombing attacks: outcomes, lessons learnt, and changes made from three attacks in Indonesia.

Science.gov (United States)

Chim, Harvey; Yew, Woon Si; Song, Colin

2007-01-01

Terror attacks in Southeast Asia were almost nonexistent until the 2002 Bali bomb blast, considered the deadliest attack in Indonesian history. Further attacks in 2003 (Jakarta), 2004 (Jakarta), and 2005 (Bali) have turned terrorist attacks into an ever-present reality. The authors reviewed medical charts of victims evacuated to the Singapore General Hospital (SGH) Burns Centre during three suicide attacks involving Bali (2002 and 2005) and the Jakarta Marriott hotel (2003). Problems faced, lessons learnt, and costs incurred are discussed. A burns disaster plan drawing on lessons learnt from these attacks is presented. Thirty-one patients were treated at the SGH Burns Centre in three attacks (2002 Bali attack [n = 15], 2003 Jakarta attack [n = 14], and 2005 Bali attack [n = 2]). For the 2002 Bali attack, median age was 29 years (range 20 to 50 years), median percentage of total burn surface area (TBSA) was 29% (range 5% to 55%), and median abbreviated burn severity index (ABSI) was 6 (range 3 to 10). Eight of 15 patients were admitted to the intensive care unit. For the 2003 Jakarta attack, median age was 35 years (range 24 to 56 years), median percentage of TBSA was 10% (range 2% to 46%), and median ABSI was 4 (range 3 to 9). A large number of patients had other injuries. Problems faced included manpower issues, lack of bed space, shortage of blood products, and lack of cadaver skin. The changing nature of terror attacks mandates continued vigilance and disaster preparedness. The multidimensional burns patient, complicated by other injuries, is likely to become increasingly common. A burns disaster plan with emphasis on effective command, control, and communication as well as organisation of health care personnel following a 'team concept' will do much to ensure that the sudden onset of a crisis situation at an unexpected time does not overwhelm hospital manpower and resources.

Overview of DOS attacks on wireless sensor networks and experimental results for simulation of interference attacks

Directory of Open Access Journals (Sweden)

Željko Gavrić

2018-01-01

Full Text Available Wireless sensor networks are now used in various fields. The information transmitted in the wireless sensor networks is very sensitive, so the security issue is very important. DOS (denial of service attacks are a fundamental threat to the functioning of wireless sensor networks. This paper describes some of the most common DOS attacks and potential methods of protection against them. The case study shows one of the most frequent attacks on wireless sensor networks – the interference attack. In the introduction of this paper authors assume that the attack interference can cause significant obstruction of wireless sensor networks. This assumption has been proved in the case study through simulation scenario and simulation results.

Genotoxic Effects of Exposure to Gasoline Fumes on Petrol Pump Workers

Directory of Open Access Journals (Sweden)

Amrin Shaikh

2018-04-01

Full Text Available Background: Petrol pump workers are occupationally exposed to gasoline and its fumes consisting of several mutagenic chemicals. Objective: To evaluate the genotoxic effects of exposure to gasoline fumes on petrol pump workers. Methods: The study groups included 70 petrol pump workers (exposed group and 70 healthy age-matched individuals with no known exposure (comparison group. Buccal micronucleus cytome assay (BMCyt was performed to check the genotoxicity caused due to inhalation of gasoline fumes. Results: The frequencies of micronucleated cells, nuclear bud, condensed chromatin cells, karyorrhectic cells, pyknotic cells, and karyolytic cells were significantly higher in the exposed workers compared to the comparison group. Conclusion: Exposure to gasoline fumes is associated with increased frequency of cell abnormalities. This may lead to various health consequences including cancer in those occupationally exposed to gasoline fumes.

Securing internet by eliminating DDOS attacks

Science.gov (United States)

Niranchana, R.; Gayathri Devi, N.; Santhi, H.; Gayathri, P.

2017-11-01

The major threat caused to the authorised usage of Internet is Distributed Denial of Service attack. The mechanisms used to prevent the DDoS attacks are said to overcome the attack’s ability in spoofing the IP packets source addresses. By utilising Internet Protocol spoofing, the attackers cause a consequential load over the networks destination for policing attack packets. To overcome the IP Spoofing level on the Internet, We propose an Inter domain Packet Filter (IPF) architecture. The proposed scheme is not based on global routing information. The packets with reliable source addresses are not rejected, the IPF frame work works in such a manner. The spoofing capability of attackers is confined by IPF, and also the filter identifies the source of an attack packet by minimal number of candidate network.

Do endogenous and exogenous action control compete for perception?

Science.gov (United States)

Pfister, Roland; Heinemann, Alexander; Kiesel, Andrea; Thomaschke, Roland; Janczyk, Markus

2012-04-01

Human actions are guided either by endogenous action plans or by external stimuli in the environment. These two types of action control seem to be mediated by neurophysiologically and functionally distinct systems that interfere if an endogenously planned action suddenly has to be performed in response to an exogenous stimulus. In this case, the endogenous representation has to be deactivated first to give way to the exogenous system. Here we show that interference of endogenous and exogenous action control is not limited to motor-related aspects but also affects the perception of action-related stimuli. Participants associated two actions with contingent sensory effects in learning blocks. In subsequent test blocks, preparing one of these actions specifically impaired responding to the associated effect in an exogenous speeded detection task, yielding a blindness-like effect for arbitrary, learned action effects. In accordance with the theory of event coding, this finding suggests that action planning influences perception even in the absence of any physical similarities between action and to-be-perceived stimuli.

Plants under dual attack

NARCIS (Netherlands)

Ponzio, C.A.M.

2016-01-01

Though immobile, plants are members of complex environments, and are under constant threat from a wide range of attackers, which includes organisms such as insect herbivores or plant pathogens. Plants have developed sophisticated defenses against these attackers, and include chemical responses

ROS-mediated genotoxicity of asbestos-cement in mammalian lung cells in vitro

Directory of Open Access Journals (Sweden)

Rödelsperger Klaus

2005-10-01

Full Text Available Abstract Asbestos is a known carcinogen and co-carcinogen. It is a persisting risk in our daily life due to its use in building material as asbestos-cement powder. The present study done on V79-cells (Chinese hamster lung cells demonstrates the cytotoxic and genotoxic potential of asbestos-cement powder (ACP in comparison with chrysotile asbestos. A co-exposure of chrysotile and ACP was tested using the cell viability test and the micronucleus assay. The kinetochore analysis had been used to analyse the pathway causing such genotoxic effects. Thiobarbituric acid-reactive substances were determined as evidence for the production of reactive oxygen species. Both, asbestos cement as well as chrysotile formed micronuclei and induced loss of cell viability in a concentration- and time- dependent way. Results of TBARS analysis and iron chelator experiments showed induction of free radicals in ACP- and chrysotile exposed cultures. CaSO4 appeared to be a negligible entity in enhancing the toxic potential of ACP. The co-exposure of both, ACP and chrysotile, showed an additive effect in enhancing the toxicity. The overall study suggests that asbestos-cement is cytotoxic as well as genotoxic in vitro. In comparison to chrysotile the magnitude of the toxicity was less, but co-exposure increased the toxicity of both.

Genotoxicity and mutagenicity of Echinodorus macrophyllus (chapéu-de-couro extracts

Directory of Open Access Journals (Sweden)

Leonardo S. Vidal

2010-01-01

Full Text Available Echinodorus macrophyllus, commonly known as chapéu-de-couro, is a medicinal plant used in folk medicine to treat inflammation and rheumatic diseases. In this work, we used short-term bacterial assays based on the induction of SOS functions to examine the genotoxicity and mutagenicity of an aqueous extract of E. macrophyllus leaves. Whole extract and an ethyl acetate fraction showed similar genotoxicity and caused an ~70-fold increase in lysogenic induction. The extract also gave a positive result in the SOS chromotest with an increase of 12-fold in β-Galactosidase enzymatic units. There was a strong trend towards base substitutions and frameshifts at purine sites in the mutations induced by the extract in Escherichia coli (CC103 and CC104 strains and Salmonella typhimurium test strains (22-fold increase in histidine revertants in TA98 strain. Since reactive oxygen species may be implicated in aging process and in degenerative diseases, we used antioxidant compounds as catalase, thiourea and dipyridyl in the lysogenic induction test. All this compounds were able to reduce the induction factor observed in the treatment with chapéu-de-couro, thus suggesting that the genotoxicity and mutagenicity were attributable to the production of reactive oxygen species that targeted DNA purines.

Evaluation of river water genotoxicity using the piscine micronucleus test.

Science.gov (United States)

Ergene, Serap; Cavaş, Tolga; Celik, Ayla; Köleli, Nurcan; Aymak, Cemil

2007-07-01

The Berdan River, which empties into the Mediterranean Sea on the east coast of Turkey, receives discharges of industrial and municipal waste. In the present study, the in vivo piscine micronucleus (MN) test was used to evaluate the genotoxicity of water samples collected from different locations along the Berdan River. Nile tilapia (Oreochromis niloticus) were exposed in the laboratory for 2, 4, and 6 days, and micronuclei were evaluated in peripheral blood erythrocytes, gill cells, and caudal fin epithelial cells. A single dose of 5 mg/L cyclophosphamide was used as a positive control. In addition to micronuclei, nuclear abnormalities (NAs), such as binucleated cells and blebbed, notched, and lobed nuclei, were assessed in the erythrocytes, and chemical analyses were carried out to determine the amount of heavy metals in the water samples. MN and NA frequencies were significantly elevated (up to 2- to 3-fold) in fish exposed to river water samples taken downstream of potential discharges, and the elevated responses in gill and fin cells were related to the concentration of heavy metals in the water. MN frequencies (expressed as micronucleated cells/1,000 cells), in both treated and untreated fish, were greatest in gill cells (range: 0.80-3.70), and generally lower in erythrocytes (range: 0.50-2.80), and fin cells (range: 0.45-1.70). The results of this study indicate that the Berdan River is contaminated with genotoxic pollutants and that the genotoxicity is related to the discharge of wastes into the river water.

New attacks on Wi-Fi Protected Setup

OpenAIRE

Hamed Mohtadi; Alireza Rahimi

2015-01-01

Wi-Fi Protected Setup (WPS) is a network security standard that is used to secure networks in home and office, introduced in 2006 by the Wi-Fi Alliance. It provides easier configuration setup and is used in almost all recent Wi-Fi devices. In this paper we propose two attacks on this standard. The first attack is an offline brute force attack that uses imbalance on registration protocol. This attack needs user action, but it is more efficient than previous attacks. The second attack uses weak...

A Game Theoretic Approach to Cyber Attack Prediction

Energy Technology Data Exchange (ETDEWEB)

Peng Liu

2005-11-28

The area investigated by this project is cyber attack prediction. With a focus on correlation-based prediction, current attack prediction methodologies overlook the strategic nature of cyber attack-defense scenarios. As a result, current cyber attack prediction methodologies are very limited in predicting strategic behaviors of attackers in enforcing nontrivial cyber attacks such as DDoS attacks, and may result in low accuracy in correlation-based predictions. This project develops a game theoretic framework for cyber attack prediction, where an automatic game-theory-based attack prediction method is proposed. Being able to quantitatively predict the likelihood of (sequences of) attack actions, our attack prediction methodology can predict fine-grained strategic behaviors of attackers and may greatly improve the accuracy of correlation-based prediction. To our best knowledge, this project develops the first comprehensive framework for incentive-based modeling and inference of attack intent, objectives, and strategies; and this project develops the first method that can predict fine-grained strategic behaviors of attackers. The significance of this research and the benefit to the public can be demonstrated to certain extent by (a) the severe threat of cyber attacks to the critical infrastructures of the nation, including many infrastructures overseen by the Department of Energy, (b) the importance of cyber security to critical infrastructure protection, and (c) the importance of cyber attack prediction to achieving cyber security.

Exogenous lipid pneumonia

International Nuclear Information System (INIS)

Bernasconi, A.; Gavelli, G.; Zompatori, M.; Galleri, C.; Zanasi, A.; Fabbri, M.; Bazzocchi, F.

1988-01-01

Exogenous lipid pneumonia (ELP) is caused by the aspiration of animal, vegetal or, more often, mineral oils. Even though it may also be acute, ELP is most frequently a chronic disease, affecting people with predisposing factors, such as neuromuscular disorders, structural abnormalities and so on; very often exogenous lipid pneumonia is found in tracheotomized patients. The pathology of lipid pneumonia is a chronic inflammatory process evolving in foreign-body-like reaction, and eventually in ''end-stage lung'' condition. Clinically, most patients are asymptomatic; few cases only present with cough, dyspnea and chest pain. Eight cases of ELP, studied over the past 3 years, are described in this paper. All the patients were examined by chest radiographs and standard tomograms; 3 patients underwent CT. X-ray features were mono/bilateral consolidation of the lower zones, with air bronchogram and variable reduction in volume. CT density was not specific for fat tissue. In all cases the diagnosis was confirmed at biopsy. In 5 patients, followed for at least one year, clinical-radiological features showed no change. Thus, complications of ELP (especially malignant evolution) could be excluded. The authors conclude that lipid pneumonia must be considered in differential diagnosis of patients with history of usage of oils and compatible X-ray findings. The usefulness of an accurate follow-up is stressed

Invisible Trojan-horse attack

DEFF Research Database (Denmark)

Sajeed, Shihan; Minshull, Carter; Jain, Nitin

2017-01-01

We demonstrate the experimental feasibility of a Trojan-horse attack that remains nearly invisible to the single-photon detectors employed in practical quantum key distribution (QKD) systems, such as Clavis2 from ID Quantique. We perform a detailed numerical comparison of the attack performance...

Exogenous Ochronosis

Directory of Open Access Journals (Sweden)

Prachi A Bhattar

2015-01-01

Full Text Available Exogenous ochronosis (EO is a cutaneous disorder characterized by blue-black pigmentation resulting as a complication of long-term application of skin-lightening creams containing hydroquinone but may also occur due to topical contact with phenol or resorcinol in dark-skinned individuals. It can also occur following the use of systemic antimalarials such as quinine. EO is clinically and histologically similar to its endogenous counterpart viz., alkaptonuria, which, however, exhibits systemic effects and is an inherited disorder. Dermoscopy and in vivo skin reflectance confocal microscopy are noninvasive in vivo diagnostic tools. It is very difficult to treat EO, a cosmetically disfiguring and troubling disorder with disappointing treatment options.

Protective effect of thymoquinone against diazinon-induced hematotoxicity, genotoxicity and immunotoxicity in rats.

Science.gov (United States)

Danaei, Gholam Hassan; Karami, Mohammad

2017-10-01

Several studies have shown that oxidative stress and cell damage can occur in the very early stages of diazinon (DZN) exposure. The present study was designed to determine the beneficial effect of thymoquinone (Thy), the main component of Nigella sativa (black seed or black cumin) against DZN immunotoxicity, hematotoxicity and genotoxicity in rats. In the present experimental study, 48 male Wistar rats were randomly divided into six groups, (eight per group) as follows: control (receiving corn oil as the DZN solvent), DZN (20mg/kg), Thy (10mg/kg), Thy (2.5mg/kg)+DZN, Thy (5mg/kg)+DZN and Thy (10mg/kg)+DZN. After four weeks of treatment, the hematological parameters of red blood cells (RBCs), white blood cells (WBCs), hemoglobin (Hb), hematocrit (Hct) and platelets (PLTs) were evaluated. The evaluation of genotoxicity was carried out using the micronucleus assay. For measurement of cytokine production, interferon gamma (IFN-γ), interleukin 10 (IL10) and interleukin 4 (IL4) were chosen as immunotoxicity indicators of DZN toxicity. DZN was found to decrease RBCs, WBCs, Hb, Hct, PLTs, butyrl- and acetyl-cholinesterase activity and I FN-γ and increased the micronucleus indices of IL10 and IL4 as compared with the control group. Treatment with Thy reduced DZN hematotoxicity and immunotoxicity, but, significantly, did not prevent genotoxicity. This study showed that Thy (without the significant effect on genotoxicity) decreased the hematological toxicity, immunotoxicity and butyrl and acetyl cholinesterase activity induced by DZN. The success of Thy supplementation against DZN toxicity can be attributed to the antioxidant effects of its constituents. Copyright © 2017. Published by Elsevier B.V.

The analgesic effects of exogenous melatonin in humans.

Science.gov (United States)

Andersen, Lars Peter Holst

2016-10-01

The hormone, melatonin is produced with circadian rhythm by the pineal gland in humans. The melatonin rhythm provides an endogenous synchronizer, modulating e.g. blood pressure, body temperature, cortisol rhythm, sleep-awake-cycle, immune function and anti-oxidative defence. Interestingly, a number of experimental animal studies demonstrate significant dose-dependent anti-nociceptive effects of exogenous melatonin. Similarly, recent experimental- and clinical studies in humans indicate significant analgesic effects. In study I, we systematically reviewed all randomized studies investigating clinical effects of perioperative melatonin. Meta-analyses demonstrated significant analgesic and anxiolytic effects of melatonin in surgical patients, equating reductions of 20 mm and 19 mm, respectively on a VAS, compared with placebo. Profound heterogeneity between the included studies was, however, present. In study II, we aimed to investigate the analgesic, anti-hyperalgesic and anti-inflammatory effects of exogenous melatonin in a validated human inflammatory pain model, the human burn model. The study was performed as a randomized, double blind placebo-controlled crossover study. Primary outcomes were pain during the burn injury and areas of secondary hyperalgesia. No significant effects of exogenous melatonin were observed with respect to primary or secondary outcomes, compared to placebo. Study III and IV estimated the pharmacokinetic variables of exogenous melatonin. Oral melatonin demonstrated a t max value of 41 minutes. Bioavailability of oral melatonin was only 3%. Elimination t 1/2 were approximately 45 minutes following both oral and intravenous administration, respectively. High-dose intravenous melatonin was not associated with increased sedation, in terms of simple reaction times, compared to placebo. Similarly, no other adverse effects were reported. In Study V, we aimed to re-analyse data obtained from a randomized analgesic drug trial by a selection of

Radiological attacks and accidents. Medical consequences

International Nuclear Information System (INIS)

Sakuta, Hidenari

2007-01-01

Probability of the occurrence of radiological attacks appears to be elevated after the terrorist attacks against the United States on September 11 in 2001. There are a lot of scenarios of radiological attack: simple radiological device, radiological disperse device (RDD or dirty bomb), attacks against nuclear reactor, improvised nuclear device, and nuclear weapons. Of these, RDD attack is the most probable scenario, because it can be easily made and can generate enormous psychological and economic damages. Radiological incidents are occurring to and fro in the world, including several cases of theft to nuclear facilities and unsuccessful terrorist attacks against them. Recently, a former Russian spy has allegedly been killed using polonium-210. In addition, serious radiological accidents have occurred in Chernobyl, Goiania, and Tokai-mura. Planning, preparation, education, and training exercise appear to be essential factors to cope with radiological attacks and accidents effectively without feeling much anxiety. Triage and psychological first aid are prerequisite to manage and provide effective medial care for mass casualties without inducing panic. (author)

Distribution of exogenous DNA in upland cotton by pollen tube pathway

International Nuclear Information System (INIS)

Yang Shuhua; Ge Cailin; Zhu Jing; Wang Zegang; Luo Shishi; Ni Wanchao

2007-01-01

The distribution of exogenous DNA in upland cotton by pollen tube pathway was studied. The results showed that the exogenous DNA could be transported into ovules by dripping and injection. The optimum time for treatment is at 33 h after pollination. The radioactivity in ovules by dripping exogenous DNA was lower than that by injecting. In autoradiogram, the number of sliver grains in the treated ovules was more than that in the controls. (authors)

In vitro cytotoxic, genotoxic and antioxidant/oxidant effects of guaiazulene on human lymphocytes

Directory of Open Access Journals (Sweden)

Başak Toğar

2015-02-01

Full Text Available The aim of this study was to evaluate for the cytotoxicity, genotoxicity and antioxidant/oxidant activity of GYZ on human peripheral blood lymphocytes (PBLs. Guaiazulene (GYZ was added into culture tubes at various concentrations (0-400 µg/mL-1. Cytotoxicity against the human lymphocytes cultures was examined by lactate dehydrogenase (LDH release assay. The proliferative response was estimated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide (MTT assay. Antioxidant/oxidant activity was evaluated by measuring the total oxidant status (TOS and total antioxidant capacity (TAC levels. Micronucleus (MN and chromosomal aberration (CA tests were used in genotoxicity studies. The results showed that GYZ caused cytotoxicity in the PBLs at high concentrations, but TOS level were not affected, while the level of TAC was significantly increased. GYZ also did not induce chromosomal aberrations when compared to that of the control group. Results this study clearly revealed that GYZ was not genotoxic and also increased the capacity of the antioxidant in the culture of human PBL cells. This report is first report on the impact of GYZ on human PBL cells.

Evaluation of Hypoglycemic and Genotoxic Effect of Polyphenolic Bark Extract from Quercus sideroxyla

Science.gov (United States)

Soto-García, Marcela; Rosales-Castro, Martha; Escalona-Cardoso, Gerardo N.

2016-01-01

Quercus sideroxyla is a wood species whose bark has phenolic compound and should be considered to be bioactive; the hypoglycemic and genotoxic properties of Q. sideroxyla bark were evaluated in this study. Total phenolic compound was determined in crude extract (CE) and organic extract (OE). The OE has the highest amount of phenols (724.1 ± 12.0 GAE/g). Besides, both CE and OE demonstrated effect over the inhibition of α-amylase in vitro. Hypoglycemic activity was assessed by glucose tolerance curve and the area under curve (UAC); OE showed the highest hypoglycemic activity. In addition, diabetes was induced by streptozotocin (65 mg/kg) and the extracts (50 mg/kg) were administered for 10 days; OE showed hypoglycemic effect compared with diabetic control and decreased hepatic lipid peroxidation. Acute toxicity and genotoxicity were evaluated in CE; results of acute toxicity did not show any mortality. Besides, the comet assay showed that CE at a dose of 100 mg/kg did not show any genotoxic effect when evaluated at 24 h, whereas it induced slight damage at 200 mg/kg, with the formation of type 1 comets. PMID:27867402

In vitro evaluation of genotoxic effects under magnetic resonant coupling wireless power transfer.

Science.gov (United States)

Mizuno, Kohei; Shinohara, Naoki; Miyakoshi, Junji

2015-04-07

Wireless power transfer (WPT) technology using the resonant coupling phenomenon has been widely studied, but there are very few studies concerning the possible relationship between WPT exposure and human health. In this study, we investigated whether exposure to magnetic resonant coupling WPT has genotoxic effects on WI38VA13 subcloned 2RA human fibroblast cells. WPT exposure was performed using a helical coil-based exposure system designed to transfer power with 85.4% efficiency at a 12.5-MHz resonant frequency. The magnetic field at the positions of the cell culture dishes is approximately twice the reference level for occupational exposure as stated in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The specific absorption rate at the positions of the cell culture dishes matches the respective reference levels stated in the ICNIRP guidelines. For assessment of genotoxicity, we studied cell growth, cell cycle distribution, DNA strand breaks using the comet assay, micronucleus formation, and hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutation, and did not detect any significant effects between the WPT-exposed cells and control cells. Our results suggest that WPT exposure under the conditions of the ICNIRP guidelines does not cause detectable cellular genotoxicity.

Evaluation of Hypoglycemic and Genotoxic Effect of Polyphenolic Bark Extract from Quercus sideroxyla

Directory of Open Access Journals (Sweden)

Marcela Soto-García

2016-01-01

Full Text Available Quercus sideroxyla is a wood species whose bark has phenolic compound and should be considered to be bioactive; the hypoglycemic and genotoxic properties of Q. sideroxyla bark were evaluated in this study. Total phenolic compound was determined in crude extract (CE and organic extract (OE. The OE has the highest amount of phenols (724.1±12.0 GAE/g. Besides, both CE and OE demonstrated effect over the inhibition of α-amylase in vitro. Hypoglycemic activity was assessed by glucose tolerance curve and the area under curve (UAC; OE showed the highest hypoglycemic activity. In addition, diabetes was induced by streptozotocin (65 mg/kg and the extracts (50 mg/kg were administered for 10 days; OE showed hypoglycemic effect compared with diabetic control and decreased hepatic lipid peroxidation. Acute toxicity and genotoxicity were evaluated in CE; results of acute toxicity did not show any mortality. Besides, the comet assay showed that CE at a dose of 100 mg/kg did not show any genotoxic effect when evaluated at 24 h, whereas it induced slight damage at 200 mg/kg, with the formation of type 1 comets.

Formation and removal of genotoxic activity during UV/H

NARCIS (Netherlands)

Heringa, M.B.; Harmsen, D.J.H.; Beerendonk, E.F.; Reus, A.A.; Krul, C.A.M.; Metz, D.H.; Ijpelaar, G.F.

2011-01-01

The objective of this study was to determine the genotoxic activity of water after UV/H₂O₂ oxidation and GAC filtration. Pre-treated surface water from three locations was treated with UV/H₂O₂ with medium pressure (MP) lamps and passed through granulated

Genotoxic effects in wild rodents (Rattus rattus and Mus musculus) in an open coal mining area.

Science.gov (United States)

León, Grethel; Pérez, Lyda Espitia; Linares, Juan Carlos; Hartmann, Andreas; Quintana, Milton

2007-06-15

Coal is a mixture of a variety of compounds containing mutagenic and carcinogenic polycyclic aromatic hydrocarbons. Exposure to coal is considered as an important non-cellular and cellular source of reactive oxygen species that can induce DNA damage. In addition, spontaneous combustion can occur in coal mining areas, further releasing compounds with detrimental effects on the environment. In this study the comet assay was used to investigate potential genotoxic effects of coal mining activities in peripheral blood cells of the wild rodents Rattus rattus and Mus musculus. The study was conducted in a coal mining area of the Municipio de Puerto Libertador, South West of the Departamento de Cordoba, Colombia. Animals from two areas in the coal mining zone and a control area located in the Municipio de Lorica were investigated. The results showed evidence that exposure to coal results in elevated primary DNA lesions in blood cells of rodents. Three different parameters for DNA damage were assessed, namely, DNA damage index, migration length and percentage damaged cells. All parameters showed statistically significantly higher values in mice and rats from the coal mining area in comparison to the animals from the control area. The parameter "DNA Damage Index" was found to be most sensitive and to best indicate a genotoxic hazard. Both species investigated were shown to be sensitive indicators of environmental genotoxicity caused by coal mining activities. In summary, our study constitutes the first investigation of potential genotoxic effects of open coal mining carried out in Puerto Libertador. The investigations provide a guide for measures to evaluate genotoxic hazards, thereby contributing to the development of appropriate measures and regulations for more careful operations during coal mining.

Script-viruses Attacks on UNIX OS

Directory of Open Access Journals (Sweden)

D. M. Mikhaylov

2010-06-01

Full Text Available In this article attacks on UNIX OS are considered. Currently antivirus developers are concentrated on protecting systems from viruses that are most common and attack popular operating systems. If the system or its components are not often attacked then the antivirus products are not protecting these components as it is not profitable. The same situation is with script-viruses for UNIX OS as most experts consider that it is impossible for such viruses to get enough rights to attack. Nevertheless the main conclusion of this article is the fact that such viruses can be very powerful and can attack systems and get enough rights.

Synergistic effect of Gentiana lutea L. on methyl methanesulfonate genotoxicity in the Drosophila wing spot test.

Science.gov (United States)

Patenković, Aleksandra; Stamenković-Radak, Marina; Nikolić, Dragana; Marković, Tamara; Anđelković, Marko

2013-03-27

Gentiana lutea L., the yellow gentian, is herb known for its pharmacological properties, with a long tradition of use for the treatment of a variety of diseases including the use as a remedy for digestion, also in food products and in bitter beverages. The aim of the present study is to evaluate, for the first time, genotoxicity of gentian alone, and its antigenotoxicity against methyl methanesulfonate (MMS). The water infusion of the underground part of gentian were evaluated in vivo using the Drosophila wing spot test, at the dose commonly used in traditional medicine. For antigenotoxic study two types of treatment with gentian and MMS were performed: chronic co-treatment, as well as post-treatment with gentian after acute exposure with MMS. Water infusion of gentian alone did not exhibit genotoxicity. The results of co- and post-treatment experiments with gentian show that gentian enhanced the frequency of mutant clones over the values obtained with MMS alone, instead of reducing the genotoxicity of MMS, for 22.64% and 27.13% respectively. This result suggests a synergism of gentian with MMS, and indicates that water infusion of gentian used in traditional medicine may have particular effects with regard to genotoxicity indicating careful use. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Biomarkers of environmental genotoxicity: comparison of genetic damage induced in Trad-SH cells and human lymphocytes

International Nuclear Information System (INIS)

Cebulska-Wasilewska, A.

1999-01-01

The report presents some of the results of genotoxicity of the environmental agents studied in somatic cells of Tradescantia and show similarity between responses of the Tradescantia stamen hair cells (Trad-SH) and human blood cells to the physical and chemical mutagens. In the studies in vitro chromosome aberrations (CA) and sister chromatid exchanges (SCE) were applied to evaluate genotoxicity of pesticides. For comparison of genotoxic effectiveness of agrochemicals with other chemicals, there are also presented results of the genotoxicity of well-known mutagens (EMS, X-rays). The results confirm that in the environment a chemical pollution might cause higher genetic risk than radiation. Trad-SH assay was applied for in situ monitoring of the ambient air mutagenicity caused by benzene and petroleum associated compounds. The studies showed that gene mutation frequencies were slightly dependent on the distance from the petroleum work center. Results of measures of the cell cycle factor have shown also that the chemical pollutants in the air played also an important role in physiological cellular processes. The similarity of the Trad-SH and human blood cells responses to the physical and chemical mutagens showed that the gene mutations in Tradescantia present a simple and sensitive model, which can be very useful in biological monitoring

Comparative Genotoxicity of Cadmium and Lead in Earthworm Coelomocytes

Directory of Open Access Journals (Sweden)

Ptumporn Muangphra

2011-01-01

Full Text Available To determine genotoxicity to coelomocytes, Pheretima peguana earthworms were exposed in filter paper studies to cadmium (Cd and lead (Pb for 48 h, at concentrations less than the LC10—Cd: 0.09, 0.19, 0.38, 0.75, and 1.50 μg cm−2; Pb: 1.65, 3.29, 6.58, 13.16, and 26.32 μg cm−2. For Cd at 0.75 μg cm−2, in the micronucleus test (detects chromosomal aberrations, significant increases (<.05 in micronuclei and binucleate cells were observed, and in the comet assay (detects DNA single-strand breaks, tail DNA% was significantly increased. Lead was less toxic with minimal effects on DNA, but the binucleates were significantly increased by Pb at 3.29 μg cm−2. This study shows that Cd is more acutely toxic and sublethally genotoxic than Pb to P. peguana. Cadmium caused chromosomal aberrations and DNA single-strand breaks at 45% of the LC10 concentration. Lead, in contrast, did not induce DNA damage but caused cytokinesis defects.

A review of the genotoxicity of trimethylolpropane triacrylate (TMPTA).

Science.gov (United States)

Kirkland, David; Fowler, Paul

2018-04-01

Trimethylolpropane triacrylate (TMPTA) is a trifunctional acrylate monomer which polymerizes rapidly when exposed to sources of free radicals. It is widely used as a reactive diluent and polymer building block in the formulation of overprint varnishes, inks and a variety of wood, plastic and metal coatings. TMPTA has been tested in a range of in vitro and in vivo genotoxicity tests. There is no clear evidence of induction of gene mutations by TMPTA in bacteria or mammalian cells in vitro, but there is evidence of clastogenicity from induction of small colony tk mutants in the mouse lymphoma assay, and also induction of micronuclei and chromosomal aberrations. However, TMPTA was negative in bone marrow or blood micronucleus tests in vivo following oral or repeated dermal application, and did not induce comets in bone marrow or liver of mice following intravenous administration, which would have achieved plasma (and therefore tissue) concentrations estimated to exceed those inducing clastogenic effects in vitro. It is concluded that TMPTA is not genotoxic in vivo. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Evaluation of genotoxic effect of silver nanoparticles (Ag-Nps) in vitro and in vivo

International Nuclear Information System (INIS)

Tavares, Priscila; Balbinot, Fernanda; Martins de Oliveira, Hugo; Elibio Fagundes, Gabriela; Venâncio, Mireli; Vieira Ronconi, João Vitor; Merlini, Aline; Streck, Emílio L.; Marques da Silva, Paula; Moraes de Andrade, Vanessa

2012-01-01

Silver nanoparticles (Ag-NPs) are the most prominent nanoproducts. Due to their antimicrobial activity, they have been incorporated in different materials, such as catheters, clothes, electric home appliance, and many others. The genotoxicity of Ag-NPs (5–45 nm), in different concentrations and times of exposure, was evaluated by the comet assay in in vitro and in vivo conditions, respectively, using human peripheral blood and Swiss mice. The results showed the genotoxic effect of Ag-NPs in vitro, in all the doses tested in the initial hour of exposure, possibly through the reactive oxygen species generation. Nevertheless, the values for this damage decrease with time, indicating that the DNA may have been restored by the repair system. In the in vivo conditions, we found no genotoxicity of Ag-NPs in any hour of exposure and any dose investigated, which can be attributed to the activation of a cellular antioxidant network and the hydrophobic nature of Ag-NPs. Now, it is absolutely necessary to investigate the role of Ag-NPs in different cell lines in vivo.

Evaluation of genotoxic effect of silver nanoparticles (Ag-Nps) in vitro and in vivo

Energy Technology Data Exchange (ETDEWEB)

Tavares, Priscila; Balbinot, Fernanda; Martins de Oliveira, Hugo; Elibio Fagundes, Gabriela [PPGCS, Universidade do Extremo Sul Catarinense, Laboratorio de Biologia Celular e Molecular (Brazil); Venancio, Mireli; Vieira Ronconi, Joao Vitor; Merlini, Aline [Universidade do Extremo Sul Catarinense, Laboratorio de Sintese de Complexos Multifuncionais (Brazil); Streck, Emilio L. [Programa de Pos-Graduacao em Ciencias da Saude, Unidade Academica de Ciencias da Saude, Universidade do Extremo Sul Catarinense, Laboratorio de Fisiopatologia Experimental (Brazil); Marques da Silva, Paula [Universidade do Extremo Sul Catarinense, Laboratorio de Sintese de Complexos Multifuncionais (Brazil); Moraes de Andrade, Vanessa, E-mail: vmoraesdeandrade@yahoo.com.br [PPGCS, Universidade do Extremo Sul Catarinense, Laboratorio de Biologia Celular e Molecular (Brazil)

2012-03-15

Silver nanoparticles (Ag-NPs) are the most prominent nanoproducts. Due to their antimicrobial activity, they have been incorporated in different materials, such as catheters, clothes, electric home appliance, and many others. The genotoxicity of Ag-NPs (5-45 nm), in different concentrations and times of exposure, was evaluated by the comet assay in in vitro and in vivo conditions, respectively, using human peripheral blood and Swiss mice. The results showed the genotoxic effect of Ag-NPs in vitro, in all the doses tested in the initial hour of exposure, possibly through the reactive oxygen species generation. Nevertheless, the values for this damage decrease with time, indicating that the DNA may have been restored by the repair system. In the in vivo conditions, we found no genotoxicity of Ag-NPs in any hour of exposure and any dose investigated, which can be attributed to the activation of a cellular antioxidant network and the hydrophobic nature of Ag-NPs. Now, it is absolutely necessary to investigate the role of Ag-NPs in different cell lines in vivo.

Comparative Cytotoxicity and Genotoxicity of Particulate and Soluble Hexavalent Chromium in Human and Sperm Whale (Physeter macrocephalus) Skin Cells

Science.gov (United States)

Li Chen, Tânia; LaCerte, Carolyne; Wise, Sandra S.; Holmes, Amie; Martino, Julieta; Wise, John Pierce; Thompson, W. Douglas; Wise, John Pierce

2014-01-01

Chromium (Cr) is a global marine pollutant, present in marine mammal tissues. Hexavalent chromium [Cr(VI)] is a known human carcinogen. In this study we compare the cytotoxic and clastogenic effects of Cr(VI) in human (Homo sapiens) and sperm whale (Physeter macrocephalus) skin fibroblasts. Our data show that increasing concentrations of both particulate and soluble Cr(VI) induce increasing amounts of cytotoxicity and clastogenicity in human and sperm whale skin cells. Furthermore, the data show that sperm whale cells are resistant to these effects exhibiting less cytotoxicity and genotoxicity than the human cells. Differences in Cr uptake accounted for some but not all of the differences in particulate and soluble Cr(VI) genotoxicity, although it did explain the differences in particulate Cr(VI) cytotoxicity. Altogether the data indicate that Cr(VI) is a genotoxic threat to whales, but also suggest that whales have evolved cellular mechanisms to protect them against the genotoxicity of environmental agents such as Cr(VI). PMID:21466859

Genotoxicity studies of organically grown broccoli (Brassica oleracea var. italica) and its interactions with urethane, methyl methanesulfonate and 4-nitroquinoline-1-oxide genotoxicity in the wing spot test of Drosophila melanogaster.

Science.gov (United States)

Heres-Pulido, María Eugenia; Dueñas-García, Irma; Castañeda-Partida, Laura; Santos-Cruz, Luis Felipe; Vega-Contreras, Viridiana; Rebollar-Vega, Rosa; Gómez-Luna, Juan Carlos; Durán-Díaz, Angel

2010-01-01

Broccoli (Brassica oleracea var. italica) has been defined as a cancer preventive food. Nevertheless, broccoli contains potentially genotoxic compounds as well. We performed the wing spot test of Drosophila melanogaster in treatments with organically grown broccoli (OGB) and co-treatments with the promutagen urethane (URE), the direct alkylating agent methyl methanesulfonate (MMS) and the carcinogen 4-nitroquinoline-1-oxide (4-NQO) in the standard (ST) and high bioactivation (HB) crosses with inducible and high levels of cytochrome P450s (CYPs), respectively. Larvae of both crosses were chronically fed with OGB or fresh market broccoli (FMB) as a non-organically grown control, added with solvents or mutagens solutions. In both crosses, the OGB added with Tween-ethanol yielded the expected reduction in the genotoxicity spontaneous rate. OGB co-treatments did not affect the URE effect, MMS showed synergy and 4-NQO damage was modulated in both crosses. In contrast, FMB controls produced damage increase; co-treatments modulated URE genotoxicity, diminished MMS damage, and did not change the 4-NQO damage. The high dietary consumption of both types of broccoli and its protective effects in D. melanogaster are discussed. Copyright 2009 Elsevier Ltd. All rights reserved.

Protective Effect of Melatonin Against Mitomycin C-Induced Genotoxic Damage in Peripheral Blood of Rats

Directory of Open Access Journals (Sweden)

S. Ortega-Gutiérrez

2009-01-01

Full Text Available Mitomycin C (MMC generates free radicals when metabolized. We investigated the effect of melatonin against MMC-induced genotoxicity in polychromatic erythrocytes and MMC-induced lipid peroxidation in brain and liver homogenates. Rats (N = 36 were classified into 4 groups: control, melatonin, MMC, and MMC + melatonin. Melatonin and MMC doses of 10 mg/kg and 2 mg/kg, respectively, were injected intraperitoneally. Peripheral blood samples were collected at 0, 24, 48, 72, and 96 hours posttreatment and homogenates were obtained at 96 hours posttreatment. The number of micronucleated polychromatic erythrocytes (MN-PCE per 1000 PCE was used as a genotoxic marker. Malondialdehyde (MDA plus 4-hydroxyalkenal (4-HDA levels were used as an index of lipid peroxidation. The MMC group showed a significant increase in MN-PCE at 24, 48, 72, and 96 hours that was significantly reduced with melatonin begin coadministrated. No significant differences were found in lipid peroxidation. Our results indicate that MMC-induced genotoxicity can be reduced by melatonin.

The current limitations of in vitro genotoxicity testing and their relevance to the in vivo situation.

Science.gov (United States)

Nesslany, Fabrice

2017-08-01

The standard regulatory core battery of genotoxicity tests generally includes 2 or 3 validated tests with at least one in vitro test in bacteria and one in vitro test on cell cultures. However, limitations in in vitro genotoxicity testing may exist at many levels. The knowledge of the underlying mechanisms of genotoxicity is particularly useful to assess the level of relevance for the in vivo situation. In order to avoid wrong conclusions regarding the actual genotoxicity status of any test substance, it appears very important to be aware of the various origins of related bias leading to 'false positives and negatives' by using in vitro methods. Among these, mention may be made on the metabolic activation system, experimental (extreme) conditions, specificities of the test systems implemented, cell type used etc. The knowledge of the actual 'limits' of the in vitro test systems used is clearly an advantage and may contribute to avoid some pitfalls in order to better assess the level of relevance for the in vivo situation. Copyright © 2016. Published by Elsevier Ltd.

Hybrid attacks on model-based social recommender systems

Science.gov (United States)

Yu, Junliang; Gao, Min; Rong, Wenge; Li, Wentao; Xiong, Qingyu; Wen, Junhao

2017-10-01

With the growing popularity of the online social platform, the social network based approaches to recommendation emerged. However, because of the open nature of rating systems and social networks, the social recommender systems are susceptible to malicious attacks. In this paper, we present a certain novel attack, which inherits characteristics of the rating attack and the relation attack, and term it hybrid attack. Furtherly, we explore the impact of the hybrid attack on model-based social recommender systems in multiple aspects. The experimental results show that, the hybrid attack is more destructive than the rating attack in most cases. In addition, users and items with fewer ratings will be influenced more when attacked. Last but not the least, the findings suggest that spammers do not depend on the feedback links from normal users to become more powerful, the unilateral links can make the hybrid attack effective enough. Since unilateral links are much cheaper, the hybrid attack will be a great threat to model-based social recommender systems.

Static magnetic field reduced exogenous oligonucleotide uptake by spermatozoa using magnetic nanoparticle gene delivery system

International Nuclear Information System (INIS)

Katebi, Samira; Esmaeili, Abolghasem; Ghaedi, Kamran

2016-01-01

Spermatozoa could introduce exogenous oligonucleotides of interest to the oocyte. The most important reason of low efficiency of sperm mediated gene transfer (SMGT) is low uptake of exogenous DNA by spermatozoa. The aim of this study was to evaluate the effects of static magnetic field on exogenous oligonucleotide uptake of spermatozoa using magnetofection method. Magnetic nanoparticles (MNPs) associated with the labeled oligonucleotides were used to increase the efficiency of exogenous oligonucleotide uptake by rooster spermatozoa. We used high-field/high-gradient magnet (NdFeB) to enhance and accelerate exogenous DNA sedimentation at the spermatozoa surface. Flow cytometry analysis was performed to measure viability and percentage of exogenous oligonucleotide uptake by sperm. Flow cytometry analysis showed a significant increase in exogenous oligonucleotide uptake by rooster spermatozoa (P<0.001) when spermatozoa were incubated in exogenous oligonucleotide solution and MNPs. However, by applying static magnetic field during magnetofection method, a significant decrease in exogenous oligonucleotide uptake was observed (P<0.05). Findings of this study showed that MNPs were effective to increase exogenous oligonucleotide uptake by rooster spermatozoa; however unlike others studies, static magnetic field, was not only ineffective to enhance exogenous oligonucleotide uptake by rooster spermatozoa but also led to reduction in efficiency of magnetic nanoparticles in gene transfer. - Highlights: • Core/shell type Iron oxide nanoparticles were used as a novel and efficient method. • This method increases exogenous DNA uptake by rooster spermatozoa. • Static magnetic field decreased DNA uptake by rooster spermatozoa.

Static magnetic field reduced exogenous oligonucleotide uptake by spermatozoa using magnetic nanoparticle gene delivery system

Energy Technology Data Exchange (ETDEWEB)

Katebi, Samira; Esmaeili, Abolghasem, E-mail: aesmaeili@sci.ui.ac.ir; Ghaedi, Kamran

2016-03-15

Spermatozoa could introduce exogenous oligonucleotides of interest to the oocyte. The most important reason of low efficiency of sperm mediated gene transfer (SMGT) is low uptake of exogenous DNA by spermatozoa. The aim of this study was to evaluate the effects of static magnetic field on exogenous oligonucleotide uptake of spermatozoa using magnetofection method. Magnetic nanoparticles (MNPs) associated with the labeled oligonucleotides were used to increase the efficiency of exogenous oligonucleotide uptake by rooster spermatozoa. We used high-field/high-gradient magnet (NdFeB) to enhance and accelerate exogenous DNA sedimentation at the spermatozoa surface. Flow cytometry analysis was performed to measure viability and percentage of exogenous oligonucleotide uptake by sperm. Flow cytometry analysis showed a significant increase in exogenous oligonucleotide uptake by rooster spermatozoa (P<0.001) when spermatozoa were incubated in exogenous oligonucleotide solution and MNPs. However, by applying static magnetic field during magnetofection method, a significant decrease in exogenous oligonucleotide uptake was observed (P<0.05). Findings of this study showed that MNPs were effective to increase exogenous oligonucleotide uptake by rooster spermatozoa; however unlike others studies, static magnetic field, was not only ineffective to enhance exogenous oligonucleotide uptake by rooster spermatozoa but also led to reduction in efficiency of magnetic nanoparticles in gene transfer. - Highlights: • Core/shell type Iron oxide nanoparticles were used as a novel and efficient method. • This method increases exogenous DNA uptake by rooster spermatozoa. • Static magnetic field decreased DNA uptake by rooster spermatozoa.

Chemical fate and genotoxic risk associated with hypochlorite treatment of nicotine

Energy Technology Data Exchange (ETDEWEB)

Zarrelli, Armando, E-mail: zarrelli@unina.it [UdR Napoli 4 Consorzio INCA, IC-REACH, Department of Organic Chemistry and Biochemistry, University Federico II, Naples (Italy); DellaGreca, Marina; Parolisi, Alice; Iesce, Maria Rosaria; Cermola, Flavio; Temussi, Fabio [UdR Napoli 4 Consorzio INCA, IC-REACH, Department of Organic Chemistry and Biochemistry, University Federico II, Naples (Italy); Isidori, Marina; Lavorgna, Margherita [Department of Life Sciences, II University of Naples, Caserta (Italy); Passananti, Monica; Previtera, Lucio [UdR Napoli 4 Consorzio INCA, IC-REACH, Department of Organic Chemistry and Biochemistry, University Federico II, Naples (Italy)

2012-06-01

Nicotine, the main alkaloid of tobacco, is a non- prescription drug to which all members of a tobacco-smoking society are exposed either through direct smoke inhalation or through second-hand passive 'smoking'. Nicotine is also commercially available in some pharmaceutical products and is used worldwide as a botanical insecticide in agriculture. Nicotine dynamics in indoor and outdoor environments as well as the human excretions and the manufacturing process are responsible for its entry in the environment through municipal and industrial wastewater discharges. The presence of nicotine in surface and ground waters points out that it survives a conventional treatment process and persists in potable-water supplies. Complete removal of nicotine is instead reported when additional chlorination steps are used. In this paper a simulation of STP chlorination of nicotine and a genotoxic evaluation of its main degradation products are reported. Under laboratory conditions removal of nicotine seems not to be due to mineralization but to transformation in oxidized and chlorinated products. The by-products have been isolated after fractionation by diverse chromatographic procedures and their structures determined using mass spectrometry and {sup 1}H and {sup 13}C NMR spectroscopy. Preliminary genotoxic SOS Chromotests with Escherichia coli PQ37 evidence no toxicity of the products. - Highlights: Black-Right-Pointing-Pointer Processes of chlorination in the treatment of raw water. Black-Right-Pointing-Pointer STP chlorination of nicotine. Black-Right-Pointing-Pointer Genotoxic evaluation of main degradation products of nicotine.

Chemical fate and genotoxic risk associated with hypochlorite treatment of nicotine

International Nuclear Information System (INIS)

Zarrelli, Armando; DellaGreca, Marina; Parolisi, Alice; Iesce, Maria Rosaria; Cermola, Flavio; Temussi, Fabio; Isidori, Marina; Lavorgna, Margherita; Passananti, Monica; Previtera, Lucio

2012-01-01

Nicotine, the main alkaloid of tobacco, is a non- prescription drug to which all members of a tobacco-smoking society are exposed either through direct smoke inhalation or through second-hand passive ‘smoking’. Nicotine is also commercially available in some pharmaceutical products and is used worldwide as a botanical insecticide in agriculture. Nicotine dynamics in indoor and outdoor environments as well as the human excretions and the manufacturing process are responsible for its entry in the environment through municipal and industrial wastewater discharges. The presence of nicotine in surface and ground waters points out that it survives a conventional treatment process and persists in potable-water supplies. Complete removal of nicotine is instead reported when additional chlorination steps are used. In this paper a simulation of STP chlorination of nicotine and a genotoxic evaluation of its main degradation products are reported. Under laboratory conditions removal of nicotine seems not to be due to mineralization but to transformation in oxidized and chlorinated products. The by-products have been isolated after fractionation by diverse chromatographic procedures and their structures determined using mass spectrometry and 1 H and 13 C NMR spectroscopy. Preliminary genotoxic SOS Chromotests with Escherichia coli PQ37 evidence no toxicity of the products. - Highlights: ► Processes of chlorination in the treatment of raw water. ► STP chlorination of nicotine. ► Genotoxic evaluation of main degradation products of nicotine.

Hexavalent chromium is cytotoxic and genotoxic to American alligator cells.

Science.gov (United States)

Wise, Sandra S; Wise, Catherine; Xie, Hong; Guillette, Louis J; Zhu, Cairong; Wise, John Pierce; Wise, John Pierce

2016-02-01

Metals are a common pollutant in the aquatic ecosystem. With global climate change, these levels are anticipated to rise as lower pH levels allow sediment bound metals to be released. The American alligator (Alligator mississippiensis) is an apex predator in the aquatic ecosystem and is considered a keystone species; as such it serves as a suitable monitor for localized pollution. One metal of increasing concern is hexavalent chromium (Cr(VI)). It is present in the aquatic environment and is a known human carcinogen and reproductive toxicant. We measured the cytotoxicity and genotoxicity of Cr(VI) in American alligator cells derived from scute tissue. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to alligator cells in a concentration-dependent manner. These data suggest that alligators may be used as a model for assessing the effects of environmental Cr(VI) contamination as well as for other metals of concern. Copyright © 2015 Elsevier B.V. All rights reserved.

Genotoxic evaluation of infusions of Urera baccifera leaves and roots in Allium cepa cells

Directory of Open Access Journals (Sweden)

Amanda L. Gindri

2015-04-01

Full Text Available Context: The aqueous extracts of Urera baccifera Wedd. leaves and roots are used to inflammatory and infectious diseases in Brazilian folk medicine. Oxalic acid, a substance co-related with toxicity and stinging, was already quantified in this plant. Aims: To evaluate the action of leaves and roots infusions (1, 30, 75 g/L and the oxalic acid standard on mitosis as indicative of presumably antimitotic and genotoxic actions, using the Allium cepa test. Methods: Oxalic acid was quantified in the roots and leaves infusions by High-performance liquid chromatography (HPLC-DAD, with the mobile phase of 25 mM phosphate buffer (pH 2.5: acetonitrile at 95:5 (v/v. To the genotoxicity test, onion bulbs were used. After the rootlets germination, each bulb was submitted for 24 h of the individual treatments. Were analyzed 1000 cells per bulb, in a total of 5000 cells per treatment. Results: Results showed that all concentrations of roots infusions induced chromosomes abnormalities, except for the highest, that caused a substantial inhibition in the mitosis, precluding to be observed abnormalities. In the leaves infusions, only the two higher concentrations caused the highest values of damage in the cellular cycle. The oxalic acid also caused abnormalities in the mitosis, and may be considered responsible by part of the genotoxic action of U. baccifera. Conclusions: Oxalic acid can be responsible by part of the chromosomal abnormalities caused by U. baccifera, although, there must have more metabolites that evoke the same effect promoting the genotoxic effect of this nettle.

Analyzing the Genotoxicity of Retroviral Vectors in Hematopoietic Cell Gene Therapy

Directory of Open Access Journals (Sweden)

Luca Biasco

2018-03-01

Full Text Available Retroviral vectors, including those derived from gammaretroviruses and lentiviruses, have found their way into the clinical arena and demonstrated remarkable efficacy for the treatment of immunodeficiencies, leukodystrophies, and globinopathies. Despite these successes, gene therapy unfortunately also has had to face severe adverse events in the form of leukemias and myelodysplastic syndromes, related to the semi-random vector integration into the host cell genome that caused deregulation of neighboring proto-oncogenes. Although improvements in vector design clearly lowered the risk of this insertional mutagenesis, analysis of potential genotoxicity and the consequences of vector integration remain important parameters for basic and translational research and most importantly for the clinic. Here, we review current assays to analyze biodistribution and genotoxicity in the pre-clinical setting and describe tools to monitor vector integration sites in vector-treated patients as a biosafety readout.

Ecotoxicity and genotoxicity of cyclophosphamide, ifosfamide, their metabolites/transformation products and their mixtures

International Nuclear Information System (INIS)

Česen, Marjeta; Eleršek, Tina; Novak, Matjaž; Žegura, Bojana; Kosjek, Tina; Filipič, Metka; Heath, Ester

2016-01-01

Cyclophosphamide (CP) and ifosfamide (IF) are commonly used cytostatic drugs that repress cell division by interaction with DNA. The present study investigates the ecotoxicity and genotoxicity of CP, IF, their human metabolites/transformation products (TPs) carboxy-cyclophosphamide (CPCOOH), keto-cyclophosphamide (ketoCP) and N-dechloroethyl-cyclophosphamide (NdCP) as individual compounds and as mixture. The two parent compounds (CP and IF), at concentrations up to 320 mg L −1 , were non-toxic towards the alga Pseudokirchneriella subcapitata and cyanobacterium Synecococcus leopoliensis. Further ecotoxicity studies of metabolites/TPs and a mixture of parent compounds and metabolites/TPs performed in cyanobacteria S. leopoliensis, showed that only CPCOOH (EC 50  = 17.1 mg L −1 ) was toxic. The measured toxicity (EC 50  = 11.5 mg L −1 ) of the mixture was lower from the toxicity predicted by concentration addition model (EC 50  = 21.1 mg L −1 ) indicating potentiating effects of the CPCOOH toxicity. The SOS/umuC assay with Salmonella typhimurium revealed genotoxic activity of CP, CPCOOH and the mixture in the presence of S9 metabolic activation. Only CPCOOH was genotoxic also in the absence of metabolic activation indicating that this compound is a direct acting genotoxin. This finding is of particular importance as in the environment such compounds can directly affect DNA of non-target organisms and also explains toxicity of CPCOOH against cyanobacteria S. leopoliensis. The degradation study with UV irradiation of samples containing CP and IF showed efficient degradation of both compounds and remained non-toxic towards S. leopoliensis, suggesting that no stable TPs with adverse effects were formed. To our knowledge, this is the first study describing the ecotoxicity and genotoxicity of the commonly used cytostatics CP and IF, their known metabolites/TPs and their mixture. The results indicate the importance of toxicological evaluation and

Neural correlates of endogenous attention, exogenous attention and inhibition of return in touch.

Science.gov (United States)

Jones, Alexander; Forster, Bettina

2014-07-01

Selective attention helps process the myriad of information constantly touching our body. Both endogenous and exogenous mechanisms are relied upon to effectively process this information; however, it is unclear how they relate in the sense of touch. In three tasks we contrasted endogenous and exogenous event-related potential (ERP) and behavioural effects. Unilateral tactile cues were followed by a tactile target at the same or opposite hand. Clear behavioural effects showed facilitation of expected targets both when the cue predicted targets at the same (endogenous predictive task) and opposite hand (endogenous counter-predictive task), and these effects also correlated with ERP effects of endogenous attention. In an exogenous task, where the cue was non-informative, inhibition of return (IOR) was observed. The electrophysiological results demonstrated early effects of exogenous attention followed by later endogenous attention modulations. These effects were independent in both the endogenous predictive and exogenous tasks. However, voluntarily directing attention away from a cued body part influenced the early exogenous marker (N80). This suggests that the two mechanisms are interdependent, at least when the task requires more demanding shifts of attention. The early marker of exogenous tactile attention, the N80, was not directly related to IOR, which may suggest that exogenous attention and IOR are not necessarily two sides of the same coin. This study adds valuable new insight into how we process and select information presented to our body, showing both independent and interdependent effects of endogenous and exogenous attention in touch. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

The effects of exogenous proline and osmotic stress on morpho ...

African Journals Online (AJOL)

USER

2010-06-21

Jun 21, 2010 ... For evaluation of growth parameters of strawberry callus under osmotic stress and exogenous proline, embryonic calli were transferred to Murashige and Skoog (MS) medium containing four sucrose. (osmotic stress) treatments including 3, 6, 9 and 12% and various concentrations of exogenous L- proline ...

Catabolism of exogenously supplied thymidine to thymine and dihydrothymine by platelets in human peripheral blood

International Nuclear Information System (INIS)

Pero, R.W.; Johnson, D.; Olsson, A.

1984-01-01

The interference of platelets with the estimation of unscheduled DNA synthesis in human peripheral mononuclear leukocytes following genotoxic exposure was studied. A 96% reduction in the unscheduled DNA synthesis value was achieved by incubating [ 3 H]thymidine with platelet-rich plasma for 5 hr at 37 degrees. Using radioactive thymine-containing compounds, together with quantitative analyses based on thin-layer and ion-exchange chromatographies, we have shown that thymidine was converted to thymine which, in turn, was converted to dihydrothymine in platelet-rich plasma. The enzymes responsible were separated from platelet lysates by gel filtration and were identified as thymidine phosphorylase and dihydrothymine dehydrogenase. The phosphorylase reversibly catalyzed the formation of thymine from thymidine and converted bromodeoxyuridine to bromouracil. The dehydrogenase reversibly catalyzed the interconversion of thymine and dihydrothymine in a reaction dependent on NADP(H), and it was inhibited by diazouracil and by thymine. Nearly all the thymidine-catabolizing activity found in whole blood samples supplied exogenously with thymidine was accounted for by the platelets. Since most genetic toxicological tests that use blood samples do not involve removing platelets from the blood cell cultures, then it is concluded that precautions should be taken in the future to determine the influence of platelets on these test systems. This is particularly true for methods dependent on thymidine pulses such as unscheduled DNA synthesis, or those dependent on bromodeoxyuridine, such as sister chromatid exchanges, since this nucleoside is also a substrate for thymidine phosphorylase

Cyto-genotoxic and DNA methylation changes induced by different crystal phases of TiO{sub 2}-np in bronchial epithelial (16-HBE) cells

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Manosij, E-mail: gmanosij@gmail.com [K.U.Leuven, Department of Public Health and Primary Care, Centre Environment & Health, B-3000 Leuven (Belgium); Öner, Deniz; Duca, Radu-Corneliu [K.U.Leuven, Department of Public Health and Primary Care, Centre Environment & Health, B-3000 Leuven (Belgium); Cokic, Stevan M. [Department of Oral Health Sciences, KU Leuven BIOMAT, 3000 Leuven (Belgium); Seys, Sven [K.U.Leuven, Department of Immunology and Microbiology, Leuven (Belgium); Kerkhofs, Stef [Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200f, Heverlee, Leuven (Belgium); Van Landuyt, Kirsten [Department of Oral Health Sciences, KU Leuven BIOMAT, 3000 Leuven (Belgium); Hoet, Peter [K.U.Leuven, Department of Public Health and Primary Care, Centre Environment & Health, B-3000 Leuven (Belgium); Godderis, Lode, E-mail: lode.godderis@med.kuleuven.be [K.U.Leuven, Department of Public Health and Primary Care, Centre Environment & Health, B-3000 Leuven (Belgium); Idewe, External Service for Prevention and Protection at Work, B-3001, Heverlee (Belgium)

2017-02-15

Highlights: • Comet and micronucleus (with and without CytB) assays revealed significant genotoxic effect of TiO{sub 2}-np. • TiO{sub 2}-np induces cell cycle arrest in the S-phase. • Anatase form induces more cyto-genotoxic effect compared to rutile and anatase-rutile mixture. • Significant hypomethylation were observed at for anatase, rutile and anatase: rutile mixture. - Abstract: With the increase in use of TiO{sub 2}-np, a better understanding of their safety is important. In the present study the effect of different crystal phases of TiO{sub 2}-np (anatase, rutile and anatase: rutile mixture; 20–26 nm) were studied for cyto-genotoxicity and global DNA methylation and hydroxymethylation. Cytotoxic response was observed at a concentration of 25 μg/ml for the particles tested. Results of comet and micronucleus (with and without CytB) assays revealed significant genotoxic effect of these particles. Flow cytometry revealed cell cycle arrest in the S-phase. Based on the results, toxicity of the particles could be correlated with their physico-chemical properties (i.e. smaller size and hydrodynamic diameter and larger surface area), anatase form being the most toxic. From the results of the cyto-genotoxicity assays, concentrations were determined for the epigenetic study. Effect on global DNA methylation and hydroxymethylation levels were studied at cyto-genotoxic (25 μg/ml), genotoxic (12.5 μg/ml) and sub cyto-genotoxic (3.25 μg/ml) concentrations using LC–MS/MS analysis. Though no significant changes were observed for 3 h treatment schedule; significant hypomethylation were observed at 24 h for anatase (significant at 3.25 and 25 μg/ml), rutile (significant at 3.25 and 25 μg/ml) and anatase: rutile mixture (significant at 25 μg/ml) forms. The results suggest that epigenetic changes could occur at sub cyto-genotoxic concentrations. And hence for complete characterization of nanoparticle toxicity, epigenetic studies should be performed along with

Evaluation of genotoxic effects of surface waters using a battery of bioassays indicating different mode of action.

Science.gov (United States)

Han, Yingnan; Li, Na; Oda, Yoshimitsu; Ma, Mei; Rao, Kaifeng; Wang, Zijian; Jin, Wei; Hong, Gang; Li, Zhiguo; Luo, Yi

2016-11-01

With the burgeoning contamination of surface waters threatening human health, the genotoxic effects of surface waters have received much attention. Because mutagenic and carcinogenic compounds in water cause tumors by different mechanisms, a battery of bioassays that each indicate a different mode of action (MOA) is required to evaluate the genotoxic effects of contaminants in water samples. In this study, 15 water samples from two source water reservoirs and surrounding rivers in Shijiazhuang city of China were evaluated for genotoxic effects. Target chemical analyses of 14 genotoxic pollutants were performed according to the Environmental quality standards for surface water of China. Then, the in vitro cytokinesis-block micronucleus (CBMN) assay, based on a high-content screening technique, was used to detect the effect of chromosome damage. The SOS/umu test using strain TA1535/pSK1002 was used to detect effects on SOS repair of gene expression. Additionally, two other strains, NM2009 and NM3009, which are highly sensitive to aromatic amines and nitroarenes, respectively, were used in the SOS/umu test to avoid false negative results. In the water samples, only two of the genotoxic chemicals listed in the water standards were detected in a few samples, with concentrations that were below water quality standards. However, positive results for the CBMN assay were observed in two river samples, and positive results for the induction of umuC gene expression in TA1535/pSK1002 were observed in seven river samples. Moreover, positive results were observed for NM2009 with S9 and NM3009 without S9 in some samples that had negative results using the strain TA1535/pSK1002. Based on the results with NM2009 and NM3009, some unknown or undetected aromatic amines and nitroarenes were likely in the source water reservoirs and the surrounding rivers. Furthermore, these compounds were most likely the causative pollutants for the genotoxic effect of these water samples. Therefore

An Analysis of Attacks on Blockchain Consensus

OpenAIRE

Bissias, George; Levine, Brian Neil; Ozisik, A. Pinar; Andresen, Gavin

2016-01-01

We present and validate a novel mathematical model of the blockchain mining process and use it to conduct an economic evaluation of the double-spend attack, which is fundamental to all blockchain systems. Our analysis focuses on the value of transactions that can be secured under a conventional double-spend attack, both with and without a concurrent eclipse attack. Our model quantifies the importance of several factors that determine the attack's success, including confirmation depth, attacke...

Automated classification of computer network attacks

CSIR Research Space (South Africa)

Van Heerden, R

2013-11-01

Full Text Available according to the relevant types of attack scenarios depicted in the ontology. The two network attack instances are the Distributed Denial of Service attack on SpamHaus in 2013 and the theft of 42 million Rand ($6.7 million) from South African Postbank...

Mixture Genotoxicity of 2,4-Dichlorophenoxyacetic Acid, Acrylamide, and Maleic Hydrazide on Human Caco-2 Cells Assessed with Comet Assay

DEFF Research Database (Denmark)

Syberg, Kristian; Binderup, Mona-Lise; Cedergreen, Nina

2015-01-01

Assessment of genotoxic properties of chemicals is mainly conducted only for single chemicals, without taking mixture genotoxic effects into consideration. The current study assessed mixture effects of the three known genotoxic chemicals, 2,4-dichlorophenoxyacetic acid (2,4-D), acrylamide (AA......), and maleic hydrazide (MH), in an experiment with a fixed ratio design setup. The genotoxic effects were assessed with the single-cell gel electrophoresis assay (comet assay) for both single chemicals and the ternary mixture. The concentration ranges used were 0-1.4, 0-20, and 0-37.7 mM for 2,4-D, AA, and MH......, respectively. Mixture toxicity was tested with a fixed ratio design at a 10:23:77% ratio for 2.4-D:AA:MH. Results indicated that the three chemicals yielded a synergistic mixture effect. It is not clear which mechanisms are responsible for this interaction. A few possible interactions are discussed...

Exogenous insulin antibody syndrome (EIAS: a clinical syndrome associated with insulin antibodies induced by exogenous insulin in diabetic patients

Directory of Open Access Journals (Sweden)

Xiaolei Hu

2018-01-01

Full Text Available Insulin has been used for diabetes therapy and has achieved significant therapeutic effect. In recent years, the use of purified and recombinant human insulin preparations has markedly reduced, but not completely suppressed, the incidence of insulin antibodies (IAs. IAs induced by exogenous insulin in diabetic patients is associated with clinical events, which is named exogenous insulin antibody syndrome (EIAS. The present review is based on our research and summarizes the characterization of IAs, the factors affecting IA development, the clinical significance of IAs and the treatments for EIAS.

Genotoxicity of Swimming Pool Water and Carcinogenicity of Drinking Water

Science.gov (United States)

Among the 11 disinfection by-products (DBPs) in drinking water that are regulated by the U.S. EPA, (a) 2 DBPs (chloroaceticacid and chlorite) are not carcinogenic-in either of2 species; (b) chlorite is not carcinogenic in 3 rodent assays and has never been tested for genotoxicity...

Genotoxicity of Swimming Pool Water and Carcinogenicity of Drinking Water**

Science.gov (United States)

Among the 11 disinfection by-products (DBPs) in drinking water that are regulated by the U.S. EPA, (a) 2 DBPs (chloroaceticacid and chlorite) are not carcinogenic-in either of2 species; (b) chlorite is not carcinogenic in 3 rodent assays and has never been tested for genotoxicity...

The effects of exogenous proline and osmotic stress on morpho ...

African Journals Online (AJOL)

For evaluation of growth parameters of strawberry callus under osmotic stress and exogenous proline, embryonic calli were transferred to Murashige and Skoog (MS) medium containing four sucrose (osmotic stress) treatments including 3, 6, 9 and 12% and various concentrations of exogenous Lproline (0, 2.5, 5 and 10 ...

Repair effects of exogenous SOD on Bacillus subtilis against gamma radiation exposure

International Nuclear Information System (INIS)

Chen, Xiaoming; Zhang, E.; Fang, Liu; Zhang, Jianguo; Zhu, Jie; He, Wei; Luo, Xuegang

2013-01-01

Superoxide dismutase (SOD) is an enzyme that removes free radicals from cells in many organisms. In order to further characterize these repair effects and their mechanism when subjected to radiation, Bacillus subtilis cells were exposed to gamma radiation and the cell survival rate, intracellular SOD activity, and DNA double-strand breakage were investigated. Vegetative cells of B. subtilis were irradiated by 60 Co gamma radiation at varying doses and subsequently exposed to varying levels of exogenous SOD. Standard plate-count, xanthine oxidase, and pulsed-field gel electrophoresis (PFGE) methods were employed to investigate the repair effects. The results showed that the exogenous SOD could significantly improve cell survival rate and intracellular SOD activity after gamma radiation. The cell survival rate was elevated 30–87 times above levels observed in control samples. Adding exogenous SOD into gamma irradiated cells may dramatically increase intracellular SOD activity (p 60 Co γ radiation and exposed to exogenous SOD. • Adding exogenous SOD into γ-irradiated cells may dramatically increase cell survival rate. • DNA strand scission may be prevented by addition of SOD. • Exogenous SOD may have the ability to repair cell damage after γ-rays radiation

A comparative analysis of property of lychee polyphenoloxidase using endogenous and exogenous substrates.

Science.gov (United States)

Sun, Jian; Shi, John; Zhao, Mouming; Xue, Sophia Jun; Ren, Jiaoyan; Jiang, Yueming

2008-06-01

Lychee polyphenoloxidase (PPO) was extracted and partially purified using ammonium sulphate precipitation and dialysis. The comparative analysis of PPO property was performed using its endogenous substrate (-)-epicatechin and exogenous substrate catechol. The pH optima for activity and activation temperature profiles of lychee PPO were very different when the enzyme reacted with endogenous and exogenous substrates. The addition of ethylenediaminetetraacetic acid disodium salt into the endogenous or exogenous substrate-enzyme system exhibited the same lowest inhibition of the PPO activity. However, l-cysteine was most effective in inhibiting enzymatic activity in the endogenous substrate-enzyme system while ascorbic acid was the best inhibitor in the exogenous substrate-enzyme system. Fe(2+) greatly accelerated the enzymatic reaction between endogenous substrate and PPO, but Cu(2+) exerted the same effect on the reaction between exogenous substrate and PPO. Based on the kinetic analysis, lychee PPO could strongly bind endogenous substrate but it possessed a higher catalytic efficiency to exogenous substrate. Copyright © 2007 Elsevier Ltd. All rights reserved.

Induction of cytotoxic and genotoxic effects of Guandu River waters in the Allium cepa system

Directory of Open Access Journals (Sweden)

Jennifer Vieira Gomes

2015-01-01

Full Text Available The Guandu River is the main source of water supply for the metropolitan region of Rio de Janeiro and has been facing serious environmental problems due to increasing population and industrial pollution, as well as the presence of polluted tributaries. This study analyzed the cytotoxic and genotoxic potential of the Guandu River’s waters, through the use of the Allium cepa test system. Collection points were chosen at the greatest confluences of pollutant sources. The sampling included two different seasons: the rainy season (January and February and the dry season (June and July. The analyses of 5000 cells per treatment showed that all the points studied had some degree of cytotoxicity and/or genotoxicity. Two sampling locations, which receive major influxes from the polluted waters of the Poços/Queimados and Cabuçu/Ipiranga Rivers, stood out for the strong presence of micronuclei, sticky chromosomes, mitotic spindle abnormalities, necrotic cells and nucleolar changes compared to the negative control. At least two locations also found changes in the mitotic index. The existence of variations in the number of cytotoxic and genotoxic changes between periods of rain and drought indicates that the cytotoxic and genotoxic potential of the water pollutants varies according to time, depending on the discharges of the tributary rivers and the increase of contaminated effluents. The results highlight the importance of bio-monitoring to assist managers in the control of effluent discharge.

Fructose and Sucrose Intake Increase Exogenous Carbohydrate Oxidation during Exercise

Science.gov (United States)

Trommelen, Jorn; Fuchs, Cas J.; Beelen, Milou; Lenaerts, Kaatje; Jeukendrup, Asker E.; Cermak, Naomi M.; van Loon, Luc J. C.

2017-01-01

Peak exogenous carbohydrate oxidation rates typically reach ~1 g·min−1 during exercise when ample glucose or glucose polymers are ingested. Fructose co-ingestion has been shown to further increase exogenous carbohydrate oxidation rates. The purpose of this study was to assess the impact of fructose co-ingestion provided either as a monosaccharide or as part of the disaccharide sucrose on exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists. Ten trained male cyclists (VO2peak: 65 ± 2 mL·kg−1·min−1) cycled on four different occasions for 180 min at 50% Wmax during which they consumed a carbohydrate solution providing 1.8 g·min−1 of glucose (GLU), 1.2 g·min−1 glucose + 0.6 g·min−1 fructose (GLU + FRU), 0.6 g·min−1 glucose + 1.2 g·min−1 sucrose (GLU + SUC), or water (WAT). Peak exogenous carbohydrate oxidation rates did not differ between GLU + FRU and GLU + SUC (1.40 ± 0.06 vs. 1.29 ± 0.07 g·min−1, respectively, p = 0.999), but were 46% ± 8% higher when compared to GLU (0.96 ± 0.06 g·min−1: p exogenous carbohydrate oxidation rates during the latter 120 min of exercise were 46% ± 8% higher in GLU + FRU or GLU + SUC compared with GLU (1.19 ± 0.12, 1.13 ± 0.21, and 0.82 ± 0.16 g·min−1, respectively, p exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists. PMID:28230742

Cyber Attacks and Combat Behavior

Directory of Open Access Journals (Sweden)

Carataș Maria Alina

2017-01-01

Full Text Available Cyber terrorism is an intangible danger, a real over the corner threat in the life of individuals,organizations, and governments and is getting harder to deal with its damages. The motivations forthe cyber-attacks are different, depending on the terrorist group, from cybercrime to hacktivism,attacks over the authorities’ servers. Organizations constantly need to find new ways ofstrengthening protection against cyber-attacks, assess their cyber readiness, expand the resiliencecapacity and adopts international security regulations.

Integrated analysis of the ecotoxicological and genotoxic effects of the antimicrobial peptide melittin on Daphnia magna and Pseudokirchneriella subcapitata

International Nuclear Information System (INIS)

Galdiero, Emilia; Maselli, Valeria; Falanga, Annarita; Gesuele, Renato; Galdiero, Stefania; Fulgione, Domenico; Guida, Marco

2015-01-01

Melittin is a major constituent of the bee venom of Apis mellifera with a broad spectrum of activities. Melittin therapeutical potential is subject to its toxicity and the assessment of ecotoxicity and genotoxicity is of particular interest for therapeutic use. Here we analyzed the biological effects of melittin on two aquatic species, which are representative of two different levels of the aquatic trophic chain: the invertebrate Daphnia magna and the unicellular microalgae Pseudokirchneriella subcapitata. The attention was focused on the determination of: i) ecotoxicity; ii) genotoxicity; iii) antigenotoxicity. Our main finding is that melittin is detrimental to D. magna reproduction and its sub-lethal concentrations create an accumulation dependent on exposition times and a negative effect on DNA. We also observed that melittin significantly delayed time to first eggs. Moreover, results showed that melittin exerted its toxic and genotoxic effects in both species, being a bit more aggressive towards P. subcapitata. - Highlights: • We examine ecotoxicity to study how AMPs affect the environment. • We examine genotoxicity in order to analyze the damages to the DNA. • We examine the antigenotoxicity in order to verify DNA repair ability of the cells. • Possible therapeutical applications of AMPs depend on assessment of ecotoxicity. - Melittin exerts its dose dependent toxic and genotoxic effects on both indicators; no toxicity is found at concentrations that may typically reach the environment

Attacks on public telephone networks: technologies and challenges

Science.gov (United States)

Kosloff, T.; Moore, Tyler; Keller, J.; Manes, Gavin W.; Shenoi, Sujeet

2003-09-01

Signaling System 7 (SS7) is vital to signaling and control in America's public telephone networks. This paper describes a class of attacks on SS7 networks involving the insertion of malicious signaling messages via compromised SS7 network components. Three attacks are discussed in detail: IAM flood attacks, redirection attacks and point code spoofing attacks. Depending on their scale of execution, these attacks can produce effects ranging from network congestion to service disruption. Methods for detecting these denial-of-service attacks and mitigating their effects are also presented.

Potential genotoxic and cytotoxicity of emamectin benzoate in human normal liver cells.

Science.gov (United States)

Zhang, Zhijie; Zhao, Xinyu; Qin, Xiaosong

2017-10-10

Pesticide residue inducing cancer-related health problems draw people more attention recently. Emamectin benzoate (EMB) has been widely used in agriculture around the world based on its specificity targets. Although potential risk and the molecular mechanism of EMB toxicity to human liver has not been well-characterized. Unlike well-reported toxicity upon central nervous system, potential genotoxic and cytotoxicity of EMB in human liver cell was ignored and very limited. In this study, we identify genotoxicity and cytotoxicity of EMB to human normal liver cells (QSG7701 cell line) in vitro . We demonstrate that EMB inhibited the viability of QSG7701 cells and induced the DNA damage. Established assays of cytotoxicity were performed to characterize the mechanism of EMB toxicity on QSG7701 cells. Typical chromatin condensation and DNA fragmentation indicated the apoptosis of QSG7701 cells induced by EMB. And the intracellular biochemical results demonstrated that EMB-enhanced apoptosis of QSG7701 cells concurrent with generated ROS, a loss of mitochondrial membrane potential, the cytochrome-c release, up regulate the Bax/Bcl-2 and the activation of caspase-9/-3. Our results of EMB induces the death of QSG7701 cells maybe via mitochondrial-mediated intrinsic apoptotic pathways would contribute to promote the awareness of EMB as an extensive used pesticide to human being effects and reveal the underlying mechanisms of potential genotoxic.

Defense and attack of complex and dependent systems

International Nuclear Information System (INIS)

Hausken, Kjell

2010-01-01

A framework is constructed for how to analyze the strategic defense of an infrastructure subject to attack by a strategic attacker. Merging operations research, reliability theory, and game theory for optimal analytical impact, the optimization program for the defender and attacker is specified. Targets can be in parallel, series, combined series-parallel, complex, k-out-of-n redundancy, independent, interdependent, and dependent. The defender and attacker determine how much to invest in defending versus attacking each of multiple targets. A target can have economic, human, and symbolic values, subjectively assessed by the defender and attacker. A contest success function determines the probability of a successful attack on each target, dependent on the investments by the defender and attacker into each target, and on characteristics of the contest. The defender minimizes the expected damage plus the defense costs. The attacker maximizes the expected damage minus the attack costs. Each agent is concerned about how his investments vary across the targets, and the impact on his utilities. Interdependent systems are analyzed where the defense and attack on one target impacts all targets. Dependent systems are analyzed applying Markov analysis and repeated games where a successful attack on one target in the first period impacts the unit costs of defense and attack, and the contest intensity, for the other target in the second period.

Defense and attack of complex and dependent systems

Energy Technology Data Exchange (ETDEWEB)

Hausken, Kjell, E-mail: kjell.hausken@uis.n [Faculty of Social Sciences, University of Stavanger, N-4036 Stavanger (Norway)

2010-01-15

A framework is constructed for how to analyze the strategic defense of an infrastructure subject to attack by a strategic attacker. Merging operations research, reliability theory, and game theory for optimal analytical impact, the optimization program for the defender and attacker is specified. Targets can be in parallel, series, combined series-parallel, complex, k-out-of-n redundancy, independent, interdependent, and dependent. The defender and attacker determine how much to invest in defending versus attacking each of multiple targets. A target can have economic, human, and symbolic values, subjectively assessed by the defender and attacker. A contest success function determines the probability of a successful attack on each target, dependent on the investments by the defender and attacker into each target, and on characteristics of the contest. The defender minimizes the expected damage plus the defense costs. The attacker maximizes the expected damage minus the attack costs. Each agent is concerned about how his investments vary across the targets, and the impact on his utilities. Interdependent systems are analyzed where the defense and attack on one target impacts all targets. Dependent systems are analyzed applying Markov analysis and repeated games where a successful attack on one target in the first period impacts the unit costs of defense and attack, and the contest intensity, for the other target in the second period.

Automated Generation of Attack Trees

DEFF Research Database (Denmark)

Vigo, Roberto; Nielson, Flemming; Nielson, Hanne Riis

2014-01-01

Attack trees are widely used to represent threat scenarios in a succinct and intuitive manner, suitable for conveying security information to non-experts. The manual construction of such objects relies on the creativity and experience of specialists, and therefore it is error-prone and impractica......Attack trees are widely used to represent threat scenarios in a succinct and intuitive manner, suitable for conveying security information to non-experts. The manual construction of such objects relies on the creativity and experience of specialists, and therefore it is error......-prone and impracticable for large systems. Nonetheless, the automated generation of attack trees has only been explored in connection to computer networks and levering rich models, whose analysis typically leads to an exponential blow-up of the state space. We propose a static analysis approach where attack trees...... are automatically inferred from a process algebraic specification in a syntax-directed fashion, encompassing a great many application domains and avoiding incurring systematically an exponential explosion. Moreover, we show how the standard propositional denotation of an attack tree can be used to phrase...

Genotoxic Pyrrolizidine Alkaloids — Mechanisms Leading to DNA Adduct Formation and Tumorigenicity

OpenAIRE

Ming W. Chou; Ge Lin; Qingsu Xia; Peter P. Fu

2002-01-01

Abstract: Plants that contain pyrrolizidine alkaloids are widely distributed in the world. Although pyrrolizidine alkaloids have been shown to be genotoxic and tumorigenic in experimental animals, the mechanisms of actions have not been fully understood. The results of our recent mechanistic studies suggest that pyrrolizidine alkaloids induce tumors via a genotoxic mechanism mediated by 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5Hpyrrolizine (DHP)-derived DNA adduct formation. This mechanism may ...

Assessment of Genotoxic Potential of Hridayarnava Rasa (A Herbo-Mineralo-Metallic Ayurvedic Formulation) Using Chromosomal Aberration and Sperm Abnormality Assays

Science.gov (United States)

Jagtap, Chandrashekhar Y.; Chaudhari, Swapnil Y.; Thakkar, Jalaram H.; Galib, R.; Prajapati, P. K.

2014-01-01

Objectives: Herbo-mineral formulations are being successfully used in therapeutics since centuries. But recently, they came under the scanner for their metallic contents especially the presence of heavy metals. Hence it is the need of the hour to assess and establish the safety of these formulations through toxicity studies. In line with the various toxicity studies that are being carried out, Government of India expressed the need for conducting genotoxicity studies of different metal- or mineral-based drugs. Till date very few Ayurvedic herbo-mineral formulations have been studied for their genotoxic potential. The present study is aimed to evaluate the genotoxic potential of Hridayarnava Rasa. Materials and Methods: It was prepared as per classical guidelines and administered to Swiss albino mice for 14 consecutive days. Chromosomal aberration and sperm abnormality assay were done to evaluate the genotoxic potential of the test drugs. Cyclophosphamide (CP) was taken as positive group and results were compared. Results: All treated groups exhibited significant body weight gain in comparison to CP group. Results revealed no structural deformity in the above parameters in comparison to the CP-treated group. Conclusion: Reported data showed that both tested samples of Hridayarnava Rasa does not possess genotoxic potential under the experimental conditions and can be safely used. PMID:25948961

A re-assessment of the safety of silver in household water treatment: rapid systematic review of mammalian in vivo genotoxicity studies.

Science.gov (United States)

Fewtrell, Lorna; Majuru, Batsirai; Hunter, Paul R

2017-06-20

Despite poor evidence of their effectiveness, colloidal silver and silver nanoparticles are increasingly being promoted for treating potentially contaminated drinking water in low income countries. Recently, however, concerns have been raised about the possible genotoxicity of particulate silver. The goal of this paper was to review the published mammalian in vivo genotoxicity studies using silver micro and nanoparticles. SCOPUS and Medline were searched using the following search string: ("DNA damage" OR genotox* OR Cytotox* OR Embryotox*) AND (silver OR AgNP). Included papers were any mammalian in vivo experimental studies investigating genotoxicity of silver particles. Studies were quality assessed using the ToxRTool. 16 relevant papers were identified. There were substantial variations in study design including the size of silver particles, animal species, target organs, silver dose, route of administration and the method used to detect genotoxicity. Thus, it was not possible to produce a definitive pooled result. Nevertheless, most studies showed evidence of genotoxicity unless using very low doses. We also identified one human study reporting evidence of "severe DNA damage" in silver jewellery workers occupationally exposed to silver particles. With the available evidence it is not possible to be definitive about risks to human health from oral exposure to silver particulates. However, the balance of evidence suggests that there should be concerns especially when considering the evidence from jewellery workers. There is an urgent need to determine whether people exposed to particulate silver as part of drinking water treatment have evidence of DNA damage.

Pareto Efficient Solutions of Attack-Defence Trees

DEFF Research Database (Denmark)

Aslanyan, Zaruhi; Nielson, Flemming

2015-01-01

Attack-defence trees are a promising approach for representing threat scenarios and possible countermeasures in a concise and intuitive manner. An attack-defence tree describes the interaction between an attacker and a defender, and is evaluated by assigning parameters to the nodes, such as proba......Attack-defence trees are a promising approach for representing threat scenarios and possible countermeasures in a concise and intuitive manner. An attack-defence tree describes the interaction between an attacker and a defender, and is evaluated by assigning parameters to the nodes......, such as probability or cost of attacks and defences. In case of multiple parameters most analytical methods optimise one parameter at a time, e.g., minimise cost or maximise probability of an attack. Such methods may lead to sub-optimal solutions when optimising conflicting parameters, e.g., minimising cost while...... maximising probability. In order to tackle this challenge, we devise automated techniques that optimise all parameters at once. Moreover, in the case of conflicting parameters our techniques compute the set of all optimal solutions, defined in terms of Pareto efficiency. The developments are carried out...

Effects of polyamines and polyamine biosynthetic inhibitors on mitotic activity of Allium cepa root tips.

Science.gov (United States)

Unal, Meral; Palavan-Unsal, Narcin; Tufekci, M A

2008-03-01

The genotoxic and cytotoxic effects of exogenous polyamines (PAs), putrescine (Put), spermidine (Spd), spermine (Spm) and PA biosynthetic inhibitors, alpha-difluoromethylornithine (DFMO), cyclohexilamine (CHA), methylglioxal bis-(guanylhydrazone) (MGBG) were investigated in the root meristems of Allium cepa L. The reduction of mitotic index and the induction of chromosomal aberrations such as bridges, stickiness, c-mitotic anaphases, micronuclei, endoredupliction by PAs and PA biosynthetic inhibitors were observed and these were used as evidence of genotoxicity and cytotoxicity.

Static magnetic field reduced exogenous oligonucleotide uptake by spermatozoa using magnetic nanoparticle gene delivery system

Science.gov (United States)

Katebi, Samira; Esmaeili, Abolghasem; Ghaedi, Kamran

2016-03-01

Spermatozoa could introduce exogenous oligonucleotides of interest to the oocyte. The most important reason of low efficiency of sperm mediated gene transfer (SMGT) is low uptake of exogenous DNA by spermatozoa. The aim of this study was to evaluate the effects of static magnetic field on exogenous oligonucleotide uptake of spermatozoa using magnetofection method. Magnetic nanoparticles (MNPs) associated with the labeled oligonucleotides were used to increase the efficiency of exogenous oligonucleotide uptake by rooster spermatozoa. We used high-field/high-gradient magnet (NdFeB) to enhance and accelerate exogenous DNA sedimentation at the spermatozoa surface. Flow cytometry analysis was performed to measure viability and percentage of exogenous oligonucleotide uptake by sperm. Flow cytometry analysis showed a significant increase in exogenous oligonucleotide uptake by rooster spermatozoa (Prooster spermatozoa; however unlike others studies, static magnetic field, was not only ineffective to enhance exogenous oligonucleotide uptake by rooster spermatozoa but also led to reduction in efficiency of magnetic nanoparticles in gene transfer.

DNA-synthesis inhibition and repair DNA-synthesis in CHO Ade- C cells: An alternative approach to genotoxicity testing

International Nuclear Information System (INIS)

Slamenova, D.; Papsova, E.; Gabelova, A.; Dusinska, M.; Collins, A.; Wsolova, L.

1997-01-01

We describe an alternative assay to determine genotoxicity. Its main feature is that it combines two measures in a single experiment; the inhibition of replicative DNA synthesis together with the stimulation of DNA repair. We show that, in tests of four different genotoxic agents, the assay gives results that are entirely consistent with what is known about the mode of action of these agents. In addition, we have demonstrated that chemical carcinogens requiring metabolic activation can be examined using a standard procedure of incubation with a microsomal activating fraction. We consider the combined assay for DNA synthesis inhibition and repair synthesis to be a useful way for the rapid pre-screening of chemicals suspected of genotoxic activity on the level of mammalian cells. (author)

Way forward in case of a false positive in vitro genotoxicity result for a cosmetic substance?

Science.gov (United States)

Doktorova, Tatyana Y; Ates, Gamze; Vinken, Mathieu; Vanhaecke, Tamara; Rogiers, Vera

2014-02-01

The currently used regulatory in vitro mutagenicity/genotoxicity test battery has a high sensitivity for detecting genotoxicants, but it suffers from a large number of irrelevant positive results (i.e. low specificity) thereby imposing the need for additional follow-up by in vitro and/or in vivo genotoxicity tests. This could have a major impact on the cosmetic industry in Europe, seen the imposed animal testing and marketing bans on cosmetics and their ingredients. Afflicted, but safe substances could therefore be lost. Using the example of triclosan, a cosmetic preservative, we describe here the potential applicability of a human toxicogenomics-based in vitro assay as a potential mechanistically based follow-up test for positive in vitro genotoxicity results. Triclosan shows a positive in vitro chromosomal aberration test, but is negative during in vivo follow-up tests. Toxicogenomics analysis unequivocally shows that triclosan is identified as a compound acting through non-DNA reactive mechanisms. This proof-of-principle study illustrates the potential of genome-wide transcriptomics data in combination with in vitro experimentation as a possible weight-of-evidence follow-up approach for de-risking a positive outcome in a standard mutagenicity/genotoxicity battery. As such a substantial number of cosmetic compounds wrongly identified as genotoxicants could be saved for the future. Copyright © 2013 Elsevier Ltd. All rights reserved.

Physicochemical characteristics, mutagenicity and genotoxicity of airborne particles under industrial and rural influences in Northern Lebanon.

Science.gov (United States)

Melki, Pamela N; Ledoux, Frédéric; Aouad, Samer; Billet, Sylvain; El Khoury, Bilal; Landkocz, Yann; Abdel-Massih, Roula M; Courcot, Dominique

2017-08-01

In this work, the main objectives were to assess the mutagenic and genotoxic effects of fine particulate matter collected in an industrial influenced site in comparison with a non-industrial influenced one (rural site) and to relate the particulate matter (PM) composition to the observed genotoxic effects. At the industrial influenced site, higher concentrations of phosphates, trace metals, and polycyclic aromatic hydrocarbons (PAHs) in particles could be related to the contributions of quarries, fertilizer producer, cement plants, and tires burning. Gasoline and diesel combustion contributions were evidenced in particles collected at both sites. Particles collected under industrial influence showed a higher mutagenic potential on three tested strains of Salmonella typhimurium (TA98, YG1041, and TA102), and especially on the YG1041, compared to particles from the rural site. Furthermore, only particles collected in the vicinity of the industrial site showed a tendency to activate the SOS responses in Escherichia coli PQ37, which is indicative of DNA damage as a result of exposure of the bacteria cells to the action of mutagenic samples. The mutagenicity and genotoxicity of the industrial PM 2.5-0.3 particulates may be attributed to its composition especially in organic compounds. This study showed that proximity of industries can affect local PM composition as well as PM genotoxic and mutagenic potential.

Hemin offers neuroprotection through inducing exogenous neuroglobin in focal cerebral hypoxic-ischemia in rats

Science.gov (United States)

Song, Xue; Xu, Rui; Xie, Fei; Zhu, Haiyuan; Zhu, Ji; Wang, Xin

2014-01-01

Objective: To investigate the inducible effect of hemin on exogenous neuroglobin (Ngb) in focal cerebral hypoxic-ischemia in rats. Methods: 125 healthy SD rats were randomly divided into five groups: sham-operation control group, operation group, hemin treatment group, exogenous Ngb treatment group, and hemin and exogenous Ngb joint treatment group. Twenty-four hours after focal cerebral hypoxic-ischemia, Ngb expression was evaluated by immunocytochemistry, RT-PCR, and western blot analyses, while the brain water content and infarct volume were examined. Results: Immunocytochemistry, RT-PCR, and western blot analyses showed more pronounced Ngb expression in the hemin and exogenous Ngb joint operation group than in the hemin or exogenous Ngb individual treatment groups, thus producing significant differences in brain water content and infarct volume (p exogenous Ngb. PMID:24966924

Cross-site scripting attacks procedure and Prevention Strategies

Directory of Open Access Journals (Sweden)

Wang Xijun

2016-01-01

Full Text Available Cross-site scripting attacks and defense has been the site of attack and defense is an important issue, this paper, the definition of cross-site scripting attacks, according to the current understanding of the chaos on the cross-site scripting, analyzes the causes and harm cross-site scripting attacks formation of attacks XXS complete process XSS attacks made a comprehensive analysis, and then for the web program includes Mobility there are cross-site scripting filter laxity given from ordinary users browse the web and web application developers two the defense cross-site scripting attacks effective strategy.

Heart Attack Symptoms in Women

Science.gov (United States)

... fat, cholesterol and other substances (plaque). Watch an animation of a heart attack . Many women think the ... Support Network Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Heart Attack Symptoms ...

On the anatomy of social engineering attacks : A literature-based dissection of successful attacks

NARCIS (Netherlands)

Bullee, Jan-Willem; Montoya, L.; Pieters, Wolter; Junger, Marianne; Hartel, Pieter H.

The aim of this studywas to explore the extent towhich persuasion principles are used in successful social engineering attacks. Seventy-four scenarioswere extracted from 4 books on social engineering (written by social engineers) and analysed. Each scenariowas split into attack steps, containing

Fipronil-induced genotoxicity and DNA damage in vivo: Protective effect of vitamin E.

Science.gov (United States)

Badgujar, P C; Selkar, N A; Chandratre, G A; Pawar, N N; Dighe, V D; Bhagat, S T; Telang, A G; Vanage, G R

2017-05-01

Fipronil, an insecticide of the phenylpyrazole class has been classified as a carcinogen by United States Environmental Protection Agency, yet very limited information is available about its genotoxic effects. Adult male and female animals were gavaged with various doses of fipronil (2.5, 12.5, and 25 mg/kg body weight (bw)) to evaluate micronucleus test (mice), chromosome aberration (CA), and comet assay (rats), respectively. Cyclophosphamide (40 mg/kg bw; intraperitoneal) was used as positive control. Another group of animals were pretreated with vitamin E orally (400 mg/kg bw) for 5 days prior to administration of fipronil (12.5 mg/kg). Fipronil exposure in both male and female mice caused significant increase in the frequency of micronuclei (MN) in polychromatic erythrocytes. Similarly, structural CAs in bone marrow cells and DNA damage in the lymphocytes was found to be significantly higher in the male and female rats exposed to fipronil as compared to their respective controls. The average degree of protection (male and female animals combined together) shown by pretreatment of vitamin E against fipronil-induced genotoxicity was 63.28%: CAs; 47.91%: MN formation; and 74.70%: DNA damage. Findings of this study demonstrate genotoxic nature of fipronil regardless of gender effect and documents protective role of vitamin E.

In Vitro Evaluation of Genotoxic Effects under Magnetic Resonant Coupling Wireless Power Transfer

Directory of Open Access Journals (Sweden)

Kohei Mizuno

2015-04-01

Full Text Available Wireless power transfer (WPT technology using the resonant coupling phenomenon has been widely studied, but there are very few studies concerning the possible relationship between WPT exposure and human health. In this study, we investigated whether exposure to magnetic resonant coupling WPT has genotoxic effects on WI38VA13 subcloned 2RA human fibroblast cells. WPT exposure was performed using a helical coil-based exposure system designed to transfer power with 85.4% efficiency at a 12.5-MHz resonant frequency. The magnetic field at the positions of the cell culture dishes is approximately twice the reference level for occupational exposure as stated in the International Commission on Non-Ionizing Radiation Protection (ICNIRP guidelines. The specific absorption rate at the positions of the cell culture dishes matches the respective reference levels stated in the ICNIRP guidelines. For assessment of genotoxicity, we studied cell growth, cell cycle distribution, DNA strand breaks using the comet assay, micronucleus formation, and hypoxanthine-guanine phosphoribosyltransferase (HPRT gene mutation, and did not detect any significant effects between the WPT-exposed cells and control cells. Our results suggest that WPT exposure under the conditions of the ICNIRP guidelines does not cause detectable cellular genotoxicity.

The Cosmetics Europe strategy for animal-free genotoxicity testing: project status up-date.

Science.gov (United States)

Pfuhler, S; Fautz, R; Ouedraogo, G; Latil, A; Kenny, J; Moore, C; Diembeck, W; Hewitt, N J; Reisinger, K; Barroso, J

2014-02-01

The Cosmetics Europe (formerly COLIPA) Genotoxicity Task Force has driven and funded three projects to help address the high rate of misleading positives in in vitro genotoxicity tests: The completed "False Positives" project optimized current mammalian cell assays and showed that the predictive capacity of the in vitro micronucleus assay was improved dramatically by selecting more relevant cells and more sensitive toxicity measures. The on-going "3D skin model" project has been developed and is now validating the use of human reconstructed skin (RS) models in combination with the micronucleus (MN) and Comet assays. These models better reflect the in use conditions of dermally applied products, such as cosmetics. Both assays have demonstrated good inter- and intra-laboratory reproducibility and are entering validation stages. The completed "Metabolism" project investigated enzyme capacities of human skin and RS models. The RS models were shown to have comparable metabolic capacity to native human skin, confirming their usefulness for testing of compounds with dermal exposure. The program has already helped to improve the initial test battery predictivity and the RS projects have provided sound support for their use as a follow-up test in the assessment of the genotoxic hazard of cosmetic ingredients in the absence of in vivo data. Copyright © 2013 Elsevier Ltd. All rights reserved.

Measurement of DNA integrity in marine gastropods as biomarker of genotoxicity

Digital Repository Service at National Institute of Oceanography (India)

Sarkar, A.; Vashistha, D.; Gupta, N.; Malik, K.; Gaitonde, D.C.S.

to identify the hot spot of pollution due to genotoxic compounds, the DNA damage was measured in terms of the loss of DNA integrity in marine gastropods due to the occurrence of DNA strand breaks following the technique of time dependent partially alkaline...

Intermediate frequency magnetic field generated by a wireless power transmission device does not cause genotoxicity in vitro.

Science.gov (United States)

Shi, Dejing; Zhu, Chunbo; Lu, Rengui; Mao, Shitong; Qi, Yanhua

2014-10-01

The aim of this study was to evaluate effects of intermediate frequency magnetic fields (IFMF) generated by a wireless power transmission (WPT) based on magnetic resonance from the perspective of cellular genotoxicity on cultured human lens epithelial cells (HLECs). We evaluated the effects of exposure to 90 kHz magnetic fields at 93.36 µT on cellular genotoxicity in vitro for 2 and 4 h. The magnetic flux density is approximately 3.5 times higher than the reference level recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. For assessment of genotoxicity, we studied cellular proliferation, apoptosis and DNA damage by Cell Counting Kit-8 (CCK-8) assay, flow cytometry analysis, alkaline comet assay and phosphorylated histone H2AX (γH2AX) foci formation test. We did not detect any effect of a 90 kHz IFMF generated by WPT based on magnetic resonance on cell proliferation, apoptosis, comet assay, and γH2AX foci formation test. Our results indicated that exposure to 90 kHz IFMF generated by WPT based on magnetic resonance at 93.36 µT for 2 and 4 h does not cause detectable cellular genotoxicity. © 2014 Wiley Periodicals, Inc.

Utilization of Photochemically Induced Fluorescence Detection for HPLC Determination of Genotoxic Impurities in the Vortioxetine Manufacturing Process.

Science.gov (United States)

Douša, Michal; Doubský, Jan; Srbek, Jan

2016-07-01

An analytical reversed-phase high-performance liquid chromatography (HPLC) method for the detection and quantitative determination of two genotoxic impurities at ppm level present in the vortioxetine manufacturing process is described. Applying the concept of threshold of toxicological concern, a limit of 75 ppm each for both genotoxic impurities was calculated based on the maximum daily dose of active pharmaceutical ingredients. The novel reversed-phase HPLC method with photochemically induced fluorescence detection was developed on XSELECT Charged Surface Hybrid Phenyl-Hexyl column using the mobile phase consisted a mixture of 10 mM ammonium formate pH 3.0 and acetonitrile. The elution was performed using an isocratic composition of 48:52 (v/v) at a flow rate of 1.0 mL/min. The photochemically induced fluorescence detection is based on the use of UV irradiation at 254 nm through measuring the fluorescence intensity at 300 nm and an excitation wavelength of 272 nm to produce fluorescent derivatives of both genotoxic impurities. The online photochemical conversion and detection is easily accomplished for two expected genotoxic impurities and provides a sufficiently low limit detection and quantification for the target analysis. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

QSAR pre-screen of 70,983 substances for genotoxic carcinogenicity, mutagenicity and developmental toxicity in the EU FP7 project ChemScreen

DEFF Research Database (Denmark)

Wedebye, Eva Bay; Dybdahl, Marianne; Nikolov, Nikolai Georgiev

2014-01-01

be performed in REACH on known genotoxic carcinogens or germ cell mutagens with appropriate risk management measures implemented, a QSAR pre-screen for genotoxic carcinogenicity, germ cell mutagenicity and (limited) developmental toxicity was included in the project. Predictions for estrogenic and anti...... algorithms were applied to combine the predictions from the individual models to reach overall predictions for genotoxic carcinogenicity, germ cell mutagenicity and developmental toxicity. Furthermore, the full list of REACH pre-registered substances (143,835) was searched for substances containing certain...

Genotoxicity of water from the Songhua River, China, in 1994-1995 and 2002-2003: Potential risks for human health

International Nuclear Information System (INIS)

Liu Jiaren; Dong Hongwei; Tang Xuanle; Sun Xiangrong; Han Xiaohui; Chen Bingqing; Sun Changhao; Yang Baofeng

2009-01-01

A previous study showed that the cancer mortalities are higher for residents who lived nearby the Songhua River heavily polluted by organic contamination. It is important to determine its risk of carcinogenic potential. Short-term genotoxic bio-assays using Salmonella, Sister Chromatid Exchange (SCE), and Micronuclei (MN) assays were employed to examine the genotoxic activity of ether extracts of water samples taken from the Songhua River. The results of the Salmonella bioassay indicated that there were indirect frame-shift mutagens in the water samples. A dose-response relationship for the SCE and MN assays was obtained. These results showed that organic extracts of water samples have genotoxic activity and the risk of carcinogenic potential to human health. The mutagenesis of water samples had changed compared to the results in 1994-1995. An increasing trend of risk of carcinogenic potential in the Songhua River after ten years should be noted and needs to be studied further. - Organic extracts of water samples taken from the Songhua River have genotoxic activity and the risk of carcinogenic potential to human health

The Vitotox and ToxTracker assays: A two-test combination for quick and reliable assessment of genotoxic hazards.

Science.gov (United States)

Ates, Gamze; Favyts, Dorien; Hendriks, Giel; Derr, Remco; Mertens, Birgit; Verschaeve, Luc; Rogiers, Vera; Y Doktorova, Tatyana

2016-11-01

To ensure safety for humans, it is essential to characterize the genotoxic potential of new chemical entities, such as pharmaceutical and cosmetic substances. In a first tier, a battery of in vitro tests is recommended by international regulatory agencies. However, these tests suffer from inadequate specificity: compounds may be wrongly categorized as genotoxic, resulting in unnecessary, time-consuming, and expensive in vivo follow-up testing. In the last decade, novel assays (notably, reporter-based assays) have been developed in an attempt to overcome these drawbacks. Here, we have investigated the performance of two in vitro reporter-based assays, Vitotox and ToxTracker. A set of reference compounds was selected to span a variety of mechanisms of genotoxic action and applicability domains (e.g., pharmaceutical and cosmetic ingredients). Combining the performance of the two assays, we achieved 93% sensitivity and 79% specificity for prediction of gentoxicity for this set of compounds. Both assays permit quick high-throughput analysis of drug candidates, while requiring only small quantities of the test substances. Our study shows that these two assays, when combined, can be a reliable method for assessment of genotoxicity hazard. Copyright © 2016 Elsevier B.V. All rights reserved.

Genotoxicity induced by Taenia solium and its reduction by immunization with calreticulin in a hamster model of taeniosis.

Science.gov (United States)

Salazar, Ana María; Mendlovic, Fela; Cruz-Rivera, Mayra; Chávez-Talavera, Oscar; Sordo, Monserrat; Avila, Guillermina; Flisser, Ana; Ostrosky-Wegman, Patricia

2013-06-01

Genotoxicity induced by neurocysticercosis has been demonstrated in vitro and in vivo in humans. The adult stage of Taenia solium lodges in the small intestine and is the main risk factor to acquire neurocysticercosis, nevertheless its carcinogenic potential has not been evaluated. In this study, we determined the genotoxic effect of T. solium infection in the hamster model of taeniosis. In addition, we assessed the effect of oral immunization with recombinant T. solium calreticulin (rTsCRT) plus cholera toxin as adjuvant on micronuclei induction, as this protein has been shown to induce 33-44% protection in the hamster model of taeniosis. Blood samples were collected from the orbital venous plexus of noninfected and infected hamsters at different days postinfection, as well as from orally immunized animals, to evaluate the frequency of micronucleated reticulocytes as a measure of genotoxicity induced by parasite exposure and rTsCRT vaccination. Our results indicate that infection with T. solium caused time-dependent DNA damage in vivo and that rTsCRT immunization reduced the genotoxic damage induced by the presence of the tapeworms. Copyright © 2013 Wiley Periodicals, Inc.

DDOS ATTACK DETECTION SIMULATION AND HANDLING MECHANISM

Directory of Open Access Journals (Sweden)

Ahmad Sanmorino

2013-11-01

Full Text Available In this study we discuss how to handle DDoS attack that coming from the attacker by using detection method and handling mechanism. Detection perform by comparing number of packets and number of flow. Whereas handling mechanism perform by limiting or drop the packets that detected as a DDoS attack. The study begins with simulation on real network, which aims to get the real traffic data. Then, dump traffic data obtained from the simulation used for detection method on our prototype system called DASHM (DDoS Attack Simulation and Handling Mechanism. From the result of experiment that has been conducted, the proposed method successfully detect DDoS attack and handle the incoming packet sent by attacker.

Model checking exact cost for attack scenarios

DEFF Research Database (Denmark)

Aslanyan, Zaruhi; Nielson, Flemming

2017-01-01

Attack trees constitute a powerful tool for modelling security threats. Many security analyses of attack trees can be seamlessly expressed as model checking of Markov Decision Processes obtained from the attack trees, thus reaping the benefits of a coherent framework and a mature tool support....... However, current model checking does not encompass the exact cost analysis of an attack, which is standard for attack trees. Our first contribution is the logic erPCTL with cost-related operators. The extended logic allows to analyse the probability of an event satisfying given cost bounds and to compute...... the exact cost of an event. Our second contribution is the model checking algorithm for erPCTL. Finally, we apply our framework to the analysis of attack trees....

Air quality biomonitoring: assessment of air pollution genotoxicity in the Province of Novara (North Italy) by using Trifolium repens L. and molecular markers.

Science.gov (United States)

Piraino, F; Aina, R; Palin, L; Prato, N; Sgorbati, S; Santagostino, A; Citterio, S

2006-12-15

Mixed air pollutants are considered a major cause of DNA damage in living species. In this study Trifolium repens L. cv Regal was used as a bioindicator to assess the genotoxicity of air stressors in the Italian province of Novara. Two on-site biomonitoring experiments were performed during the spring and autumn of 2004. Test plants were exposed at 19 monitoring sites distributed homogeneously throughout the province, and each experiment lasted for a period of 6 weeks. Genotoxicity was evaluated with Amplified Fragment Length Polymorphism (AFLP) molecular markers. The results show the predominantly rural central-west region of the Novara Province to have the worst air quality with regard to genotoxicity. Analyses of geomorphology, land use and climatic factors suggest that the compromised air quality in the region could be attributed to wind strength and direction, transporting pollution from vehicular traffic on the A4 highway and from the urban/industrialized centres of Novara and Vercelli. Plant growth, changes in plant photochemical efficiency and the presence of ozone related leaf injuries were also measured to better interpret the results of genotoxicity. Statistical analyses show that although climatic factors such as light intensity and temperature influence plant growth, they do not contribute to atmospheric stressor-induced DNA damage. Further analyses indicated that, as expected, a mixture of genotoxic and non-genotoxic pollutants coexist in the Novara Province troposphere, and that the elevated ozone concentrations experienced during the study may have contributed to the DNA damage in the tested plants by enhancing genotoxicity via interaction with other air stressors.

Workshop. Assessment of Occupational and Environmental Exposure to Genotoxic Substances - a Methodological Approach

International Nuclear Information System (INIS)

2000-01-01

During the workshop various works concerning radiobiology, environmental and occupational medicine were presented. Exposure to genotoxic and carcinogenic agents, like ionizing radiation, aromatic hydrocarbons, herbicides, pesticides was investigated

NETWORK SECURITY ATTACKS. ARP POISONING CASE STUDY

Directory of Open Access Journals (Sweden)

Luminiţa DEFTA

2010-12-01

Full Text Available Arp poisoning is one of the most common attacks in a switched network. A switch is a network device that limits the ability of attackers that use a packet sniffer to gain access to information from internal network traffic. However, using ARP poisoning the traffic between two computers can be intercepted even in a network that uses switches. This method is known as man in the middle attack. With this type of attack the affected stations from a network will have invalid entries in the ARP table. Thus, it will contain only the correspondence between the IP addresses of the stations from the same network and a single MAC address (the station that initiated the attack. In this paper we present step by step the initiation of such an attack in a network with three computers. We will intercept the traffic between two stations using the third one (the attacker.

Protective Effects of Quercetin against Dimethoate-Induced Cytotoxicity and Genotoxicity in Allium sativum Test.

Science.gov (United States)

Ahmad, Waseem; Shaikh, Sibhghatulla; Nazam, Nazia; Lone, Mohammad Iqbal

2014-01-01

The present investigation was directed to study the possible protective activity of quercetin-a natural antioxidant against dimethoate-induced cyto- and genotoxicity in meristematic cells of Allium sativum. So far there is no report on the biological properties of quercetin in plant test systems. Chromosome breaks, multipolar anaphase, stick chromosome, and mitotic activity were undertaken in the current study as markers of cyto- and genotoxicity. Untreated control, quercetin controls (@ 5, 10 and 20 μg/mL for 3 h), and dimethoate exposed groups (@ 100 and 200 μg/mL for 3 h) were maintained. For protection against cytogenotoxicity, the root tip cells treated with dimethoate at 100 and 200 μg/mL for 3 h and quercetin treatment at 5, 10, and 20 μg/mL for 16 h, prior to dimethoate treatment, were undertaken. Quercetin was found to be neither cytotoxic nor genotoxic in Allium sativum control at these doses. A significant increase (P Allium. Pretreatment of Allium sativum with quercetin significantly (P Allium sativum that resides, at least in part, on its antioxidant effects.

Cytotoxic and genotoxic effects caused by 153 Sm-EDTMP, combined with BrdU a thymidine analog

International Nuclear Information System (INIS)

Morales A, E.; Ferro F, G.; Morales R, P.

2006-01-01

The ablation of the bone marrow previous to the transplant by means of radiation and chemical antineoplastics its affect indiscriminately to the healthy tissues and in particular those that are in proliferation. The objective of this work is to determine the effect of the incorporation from the BrdU to the DNA on the genotoxicity and cytotoxicity of the cells of the bone marrow caused by the radiopharmaceutical 153 Sm-EDTMP. The genotoxicity was determined by the rate of erythrocytes polychromatic micro nucleates (EPC-MN) and the cytotoxicity by the frequency of EPC. Both parameters determined in peripheral blood after the BrdU administration and 153 Sm-EDTMP. The combination of the BrdU and r1 radiopharmaceutical produced a bigger cytotoxicity that the radiation and the BrdU alone; on the other hand it produced a reduction of the EPC-MN produced by the radiation, suggesting that the cytotoxicity didn't allow the expression of the genotoxicity. (Author)

Randomly amplified polymorphic-DNA analysis for detecting genotoxic effects of Boron on maize (Zea mays L.).

Science.gov (United States)

Sakcali, M Serdal; Kekec, Guzin; Uzonur, Irem; Alpsoy, Lokman; Tombuloglu, Huseyin

2015-08-01

This study was carried out to investigate the genotoxic effect of boron (B) on maize using randomly amplified polymorphic DNA (RAPD) method. Experimental design was conducted under 0, 5, 10, 25, 50, 100, 125, and 150 ppm B exposures, and physiological changes have revealed a sharp decrease in root growth rates from 28% to 85%, starting from 25 ppm to 150 ppm, respectively. RAPD-polymerase chain reaction (PCR) analysis shows that DNA alterations are clearly observed from beginning to 100 ppm. B-induced inhibition in root growth had a positive correlation with DNA alterations. Total soluble protein, root and stem lengths, and B content analysis in root and leaves encourage these results as a consequence. These preliminary findings reveal that B causes chromosomal aberration and genotoxic effects on maize. Meanwhile, usage of RAPD-PCR technique is a suitable biomarker to detect genotoxic effect of B on maize and other crops for the future. © The Author(s) 2013.

Endogenous versus Exogenous Growth Factor Regulation of Articular Chondrocytes

Science.gov (United States)

Shi, Shuiliang; Chan, Albert G.; Mercer, Scott; Eckert, George J.; Trippel, Stephen B.

2014-01-01

Anabolic growth factors that regulate the function of articular chondrocytes are candidates for articular cartilage repair. Such factors may be delivered by pharmacotherapy in the form of exogenous proteins, or by gene therapy as endogenous proteins. It is unknown whether delivery method influences growth factor effectiveness in regulating articular chondrocyte reparative functions. We treated adult bovine articular chondrocytes with exogenous recombinant insulin-like growth factor-I (IGF-I) and transforming growth factor-beta1 (TGF-β1), or with the genes encoding these growth factors for endogenous production. Treatment effects were measured as change in chondrocyte DNA content, glycosaminoglycan production, and aggrecan gene expression. We found that IGF-I stimulated chondrocyte biosynthesis similarly when delivered by either exogenous or endogenous means. In contrast, exogenous TGF-ß1 stimulated these reparative functions, while endogenous TGF-ß1 had little effect. Endogenous TGF-ß1 became more bioactive following activation of the transgene protein product. These data indicate that effective mechanisms of growth factor delivery for articular cartilage repair may differ for different growth factors. In the case of IGF-I, gene therapy or protein therapy appear to be viable options. In contrast, TGF-ß1 gene therapy may be constrained by a limited ability of chondrocytes to convert latent complexes to an active form. PMID:24105960

Optimizing Multireservoir System Operating Policies Using Exogenous Hydrologic Variables

Science.gov (United States)

Pina, Jasson; Tilmant, Amaury; Côté, Pascal

2017-11-01

Stochastic dual dynamic programming (SDDP) is one of the few available algorithms to optimize the operating policies of large-scale hydropower systems. This paper presents a variant, called SDDPX, in which exogenous hydrologic variables, such as snow water equivalent and/or sea surface temperature, are included in the state space vector together with the traditional (endogenous) variables, i.e., past inflows. A reoptimization procedure is also proposed in which SDDPX-derived benefit-to-go functions are employed within a simulation carried out over the historical record of both the endogenous and exogenous hydrologic variables. In SDDPX, release policies are now a function of storages, past inflows, and relevant exogenous variables that potentially capture more complex hydrological processes than those found in traditional SDDP formulations. To illustrate the potential gain associated with the use of exogenous variables when operating a multireservoir system, the 3,137 MW hydropower system of Rio Tinto (RT) located in the Saguenay-Lac-St-Jean River Basin in Quebec (Canada) is used as a case study. The performance of the system is assessed for various combinations of hydrologic state variables, ranging from the simple lag-one autoregressive model to more complex formulations involving past inflows, snow water equivalent, and winter precipitation.

Matching cue size and task properties in exogenous attention.

Science.gov (United States)

Burnett, Katherine E; d'Avossa, Giovanni; Sapir, Ayelet

2013-01-01

Exogenous attention is an involuntary, reflexive orienting response that results in enhanced processing at the attended location. The standard view is that this enhancement generalizes across visual properties of a stimulus. We test whether the size of an exogenous cue sets the attentional field and whether this leads to different effects on stimuli with different visual properties. In a dual task with a random-dot kinematogram (RDK) in each quadrant of the screen, participants discriminated the direction of moving dots in one RDK and localized one red dot. Precues were uninformative and consisted of either a large or a small luminance-change frame. The motion discrimination task showed attentional effects following both large and small exogenous cues. The red dot probe localization task showed attentional effects following a small cue, but not a large cue. Two additional experiments showed that the different effects on localization were not due to reduced spatial uncertainty or suppression of RDK dots in the surround. These results indicate that the effects of exogenous attention depend on the size of the cue and the properties of the task, suggesting the involvement of receptive fields with different sizes in different tasks. These attentional effects are likely to be driven by bottom-up mechanisms in early visual areas.

Evaluation of Genotoxic and Cytotoxic Effects in Human Peripheral Blood Lymphocytes Exposed In Vitro to Neonicotinoid Insecticides News

Directory of Open Access Journals (Sweden)

María Elena Calderón-Segura

2012-01-01

Full Text Available Calypso (thiacloprid, Poncho (clothianidin, Gaucho (imidacloprid, and Jade (imidacloprid are commercial neonicotinoid insecticides, a new class of agrochemicals in México. However, genotoxic and cytotoxic studies have not been performed. In the present study, human peripheral blood lymphocytes (PBL were exposed in vitro to different concentrations of the four insecticides. The genotoxic and cytotoxic effects were evaluated using the alkaline comet and trypan blue dye exclusion assays. DNA damage was evaluated using two genotoxicity parameters: tail length and comet frequency. Exposure to 9.5×10-6 to 5.7×10-5 M Jade; 2.8×10-4 to 1.7×10-3 M Gaucho; 0.6×10-1 to 1.4×10-1 M Calypso; 1.2×10-1 to 9.5×10-1 M Poncho for 2 h induced a significant increase DNA damage with a concentration-dependent relationship. Jade was the most genotoxic of the four insecticides studied. Cytotoxicity was observed in cells exposed to 18×10-3 M Jade, 2.0×10-3 M Gaucho, 2.0×10-1 M Calypso, 1.07 M Poncho, and cell death occurred at 30×10-3 M Jade, 3.3×10-3 M Gaucho, 2.8×10-1 M Calypso, and 1.42 M Poncho. This study provides the first report of genotoxic and cytotoxic effects in PBL following in vitro exposure to commercial neonicotinoid insecticides.

Embryotoxicity and genotoxicity evaluation of sediments from Yangtze River estuary using zebrafish (Danio rerio) embryos.

Science.gov (United States)

Li, Qian; Chen, Ling; Liu, Li; Wu, Lingling

2016-03-01

Sediments function both as a sink and a source of pollutants in aquatic ecosystems and may impose serious effects on benthic organisms and human health. As one of the largest estuaries in the world, the Yangtze River estuary suffers from abundant wastewater from the coastal cities. In this study, the zebrafish (Danio rerio) embryos were employed in the fish embryo test and a comet assay to evaluate the embryotoxicity and genotoxicity of the sediments from the Yangtze River estuary, respectively. Results showed that the sediments from the Yangtze River estuary significantly increased mortality, induced development abnormalities, and reduced hatching rate and heart rate of zebrafish embryos after 96 h of exposure. Significant genotoxicity was observed in the samples relative to the controls. Relatively low-level embryotoxicity and genotoxicity of sediments were found in the Yangtze River compared with other river systems. Toxic responses were also discussed in relation to the analyzed organic contaminants in sediments. More attention should be paid to non-priority pollutant monitoring in the Yangtze River estuary.

Understanding How Components of Organisations Contribute to Attacks

DEFF Research Database (Denmark)

Gu, Min; Aslanyan, Zaruhi; Probst, Christian W.

2016-01-01

Attacks on organisations today explore many different layers, including buildings infrastructure, IT infrastructure, and human factor – the physical, virtual, and social layer. Identifying possible attacks, understanding their impact, and attributing their origin and contributing factors is diffi......Attacks on organisations today explore many different layers, including buildings infrastructure, IT infrastructure, and human factor – the physical, virtual, and social layer. Identifying possible attacks, understanding their impact, and attributing their origin and contributing factors...... is difficult. Recently, system models have been used for automatically identifying possible attacks on the modelled organisation. The generated attacks consider all three layers, making the contribution of building infrastructure, computer infrastructure, and humans (insiders and outsiders) explicit. However......, this contribution is only visible in the attack trees as part of the performed steps; it cannot be mapped back to the model directly since the actions usually involve several elements (attacker and targeted actor or asset). Especially for large attack trees, understanding the relations between several model...

Attack Graph Construction for Security Events Analysis

Directory of Open Access Journals (Sweden)

Andrey Alexeevich Chechulin

2014-09-01

Full Text Available The paper is devoted to investigation of the attack graphs construction and analysis task for a network security evaluation and real-time security event processing. Main object of this research is the attack modeling process. The paper contains the description of attack graphs building, modifying and analysis technique as well as overview of implemented prototype for network security analysis based on attack graph approach.

Automated Discovery of Mimicry Attacks

National Research Council Canada - National Science Library

Giffin, Jonathon T; Jha, Somesh; Miller, Barton P

2006-01-01

.... These systems are useful only if they detect actual attacks. Previous research developed manually-constructed mimicry and evasion attacks that avoided detection by hiding a malicious series of system calls within a valid sequence allowed by the model...

Object-centered representations support flexible exogenous visual attention across translation and reflection.

Science.gov (United States)

Lin, Zhicheng

2013-11-01

Visual attention can be deployed to stimuli based on our willful, top-down goal (endogenous attention) or on their intrinsic saliency against the background (exogenous attention). Flexibility is thought to be a hallmark of endogenous attention, whereas decades of research show that exogenous attention is attracted to the retinotopic locations of the salient stimuli. However, to the extent that salient stimuli in the natural environment usually form specific spatial relations with the surrounding context and are dynamic, exogenous attention, to be adaptive, should embrace these structural regularities. Here we test a non-retinotopic, object-centered mechanism in exogenous attention, in which exogenous attention is dynamically attracted to a relative, object-centered location. Using a moving frame configuration, we presented two frames in succession, forming either apparent translational motion or in mirror reflection, with a completely uninformative, transient cue presented at one of the item locations in the first frame. Despite that the cue is presented in a spatially separate frame, in both translation and mirror reflection, behavioralperformance in visual search is enhanced when the target in the second frame appears at the same relative location as the cue location than at other locations. These results provide unambiguous evidence for non-retinotopic exogenous attention and further reveal an object-centered mechanism supporting flexible exogenous attention. Moreover, attentional generalization across mirror reflection may constitute an attentional correlate of perceptual generalization across lateral mirror images, supporting an adaptive, functional account of mirror images confusion. Copyright © 2013 Elsevier B.V. All rights reserved.

Human biological monitoring of occupational genotoxic exposures

DEFF Research Database (Denmark)

Knudsen, Lisbeth E.; Sorsa, M

1993-01-01

Human biological monitoring is a valuable tool for exposure assessment in groups of persons occupationally exposed to genotoxic agents. If the monitoring activity covers genetic material the term genetic monitoring is used. The methods used for genetic monitoring are either substance specific, e......) occupational exposure limit value of styrene in ambient air. The consideration of ethical issues in human genetic monitoring is an important but often overlooked aspect. This includes the scientific and preventional relevance of performing a test on individuals, pre- and post study information of donors...

Anti-Genotoxic Potential of Bilirubin In Vivo

DEFF Research Database (Denmark)

Wallner, Marlies; Antl, Nadja; Rittmannsberger, Barbara

2013-01-01

The bile pigment bilirubin is a known antioxidant and is associated with protection from cancer and cardiovascular disease (CVD) when present in too strong concentrations. Unconjugated bilirubin (UCB) might also possess anti-genotoxic potential by preventing oxidative damage to DNA. Moderately...... elevated bilirubin levels are found in individuals with Gilbert syndrome and more severe in the hyperbilirubinemic Gunn rat model. This study was therefore aimed to assess the levels of oxidative damage to DNA in Gilbert syndrome subjects and Gunn rats compared to matched controls. Seventy-six individuals...

Acute effects of a prooxidant herbicide on the microalga Chlamydomonas reinhardtii: Screening cytotoxicity and genotoxicity endpoints

International Nuclear Information System (INIS)

Esperanza, Marta; Cid, Ángeles; Herrero, Concepción; Rioboo, Carmen

2015-01-01

Highlights: • Mitochondrial membrane potential constituted the most sensitive parameter assayed. • Several genotoxicity methods were applied for first time in ecotoxicological studies. • Oxidative DNA base damage (8-OHdG) was induced by paraquat exposure. • Cells with DNA strand breakage and subG1-nuclei increased in treated cultures. • Typical apoptosis hallmarks were observed in microalgal cells exposed to paraquat. - Abstract: Since recent evidence has demonstrated that many types of chemicals exhibit oxidative and/or genotoxic potential on living organisms, reactive oxygen species (ROS) formation and DNA damage are currently the best accepted paradigms to assess the potential hazardous biological effects of a wide range of contaminants. The goal of this study was to evaluate the sensitivity of different cytotoxicity and genotoxicity responses on the model microalga Chlamydomonas reinhardtii exposed to the prooxidant herbicide paraquat. In addition to the growth endpoint, cell viability, mitochondrial membrane potential and presence of reactive oxygen species (ROS) were assayed as potential markers of cytotoxicity using flow cytometry (FCM). To study the effects of paraquat on C. reinhardtii DNA, several genotoxicity approaches were implemented for the first time in an ecotoxicological study on microalgae. Oxidative DNA base damage was analysed by measuring the oxidative DNA lesion 8-OHdG by FCM. DNA fragmentation was analysed by different methods: comet assay, and cell cycle analysis by FCM, with a particular focus on the presence of subG1-nuclei. Finally, effects on morphology of nuclei were monitored through DAPI staining. The evaluation of these endpoints showed that several physiological and biochemical parameters reacted to oxidative stress disturbances with greater sensitivity than integrative parameters such as growth rates or cell viability. The experiments revealed concentration-dependent cytotoxicity (ROS formation, depolarization of

Acute effects of a prooxidant herbicide on the microalga Chlamydomonas reinhardtii: Screening cytotoxicity and genotoxicity endpoints

Energy Technology Data Exchange (ETDEWEB)

Esperanza, Marta; Cid, Ángeles; Herrero, Concepción; Rioboo, Carmen, E-mail: carmen.rioboo@udc.es

2015-08-15

Highlights: • Mitochondrial membrane potential constituted the most sensitive parameter assayed. • Several genotoxicity methods were applied for first time in ecotoxicological studies. • Oxidative DNA base damage (8-OHdG) was induced by paraquat exposure. • Cells with DNA strand breakage and subG1-nuclei increased in treated cultures. • Typical apoptosis hallmarks were observed in microalgal cells exposed to paraquat. - Abstract: Since recent evidence has demonstrated that many types of chemicals exhibit oxidative and/or genotoxic potential on living organisms, reactive oxygen species (ROS) formation and DNA damage are currently the best accepted paradigms to assess the potential hazardous biological effects of a wide range of contaminants. The goal of this study was to evaluate the sensitivity of different cytotoxicity and genotoxicity responses on the model microalga Chlamydomonas reinhardtii exposed to the prooxidant herbicide paraquat. In addition to the growth endpoint, cell viability, mitochondrial membrane potential and presence of reactive oxygen species (ROS) were assayed as potential markers of cytotoxicity using flow cytometry (FCM). To study the effects of paraquat on C. reinhardtii DNA, several genotoxicity approaches were implemented for the first time in an ecotoxicological study on microalgae. Oxidative DNA base damage was analysed by measuring the oxidative DNA lesion 8-OHdG by FCM. DNA fragmentation was analysed by different methods: comet assay, and cell cycle analysis by FCM, with a particular focus on the presence of subG1-nuclei. Finally, effects on morphology of nuclei were monitored through DAPI staining. The evaluation of these endpoints showed that several physiological and biochemical parameters reacted to oxidative stress disturbances with greater sensitivity than integrative parameters such as growth rates or cell viability. The experiments revealed concentration-dependent cytotoxicity (ROS formation, depolarization of

Xylo-Oligosaccharides and Inulin Affect Genotoxicity and Bacterial Populations Differently in a Human Colonic Simulator Challenged with Soy Protein

Science.gov (United States)

Christophersen, Claus T.; Petersen, Anne; Licht, Tine R.; Conlon, Michael A.

2013-01-01

High dietary intakes of some protein sources, including soy protein, can increase colonic DNA damage in animals, whereas some carbohydrates attenuate this. We investigated whether inulin and xylo-oligosaccharides (XOS) could be protective against DNA strand breaks by adding them to a human colonic simulator consisting of a proximal vessel (PV) (pH 5.5) and a distal vessel (DV) (pH 6.8) inoculated with human faeces and media containing soy protein. Genotoxicity of the liquid phase and microbial population changes in the vessels were measured. Soy protein (3%) was fermented with 1% low amylose cornstarch for 10 day followed by soy protein with 1% XOS or 1% inulin for 10 day. Inulin did not alter genotoxicity but XOS significantly reduced PV genotoxicity and increased DV genotoxicity. Inulin and XOS significantly increased butyrate concentration in the DV but not PV. Numbers of the key butyrate-producing bacterium Faecalibacterium prausnitzii were significantly increased in the PV and DV by inulin but significantly decreased by XOS in both vessels. Other bacteria examined were also significantly impacted by the carbohydrate treatments or by the vessel (i.e., pH). There was a significant overall inverse correlation between levels of damage induced by the ferments and levels of sulphate-reducing bacteria, Bacteroides fragilis, and acetate. In conclusion, dietary XOS can potentially modulate the genotoxicity of the colonic environment and specific bacterial groups and short chain fatty acids may mediate this. PMID:24064573

Amplification of arsenic genotoxicity by TiO2 nanoparticles in mammalian cells: new insights from physicochemical interactions and mitochondria.

Science.gov (United States)

Wang, Xinan; Liu, Yun; Wang, Juan; Nie, Yaguang; Chen, Shaopeng; Hei, Tom K; Deng, Zhaoxiang; Wu, Lijun; Zhao, Guoping; Xu, An

2017-10-01

Titanium dioxide nanoparticles (TiO 2 NPs) have shown great adsorption capacity for arsenic (As); however, the potential impact of TiO 2 NPs on the behavior and toxic responses of As remains largely unexplored. In the present study, we focused on the physicochemical interaction between TiO 2 NPs and As(III) to clarify the underlying mechanisms involved in their synergistic genotoxic effect on mammalian cells. Our data showed that As(III) mainly interacted with TiO 2 NPs by competitively occupying the sites of hydroxyl groups on the surface of TiO 2 NP aggregates, resulting in more aggregation of TiO 2 NPs. Although TiO 2 NPs at concentrations used here had no cytotoxic or genotoxic effects on cells, they efficiently increased the genotoxicity of As(III) in human-hamster hybrid (A L ) cells. The synergistic genotoxicity of TiO 2 NPs and As(III) was partially inhibited by various endocytosis pathway inhibitors while it was completely blocked by an As(III)-specific chelator. Using a mitochondrial membrane potential fluorescence probe, a reactive oxygen species (ROS) probe together with mitochondrial DNA-depleted ρ 0 A L cells, we discovered that mitochondria were essential for mediating the synergistic DNA-damaging effects of TiO 2 NPs and As(III). These data provide novel mechanistic proof that TiO 2 NPs enhanced the genotoxicity of As(III) via physicochemical interactions, which were mediated by mitochondria-dependent ROS.

The cda GenoTox assay: A new and sensitive method for detection of environmental genotoxins, including nitroarenes and aromatic amines

DEFF Research Database (Denmark)

Østergaard, Trine G.; Hansen, Lars Henrik; Binderup, Mona-Lise

2007-01-01

A new bacterial test system for detection of genotoxic compounds was developed, based on two new Sahnonella typhimurium tester strains, TGO1 and TGO2. Both strains contain a gene fusion between a strong SOS-promotor, P-cda, and the gfp gene, which allows detection of genotoxic compounds that indu...

The use of dose-response data in a margin of exposure approach to carcinogenic risk assessment for genotoxic chemicals in food.

Science.gov (United States)

Benford, Diane J

2016-05-01

Genotoxic substances are generally not permitted for deliberate use in food production. However, an appreciable number of known or suspected genotoxic substances occur unavoidably in food, e.g. from natural occurrence, environmental contamination and generation during cooking and processing. Over the past decade a margin of exposure (MOE) approach has increasingly been used in assessing the exposure to substances in food that are genotoxic and carcinogenic. The MOE is defined as a reference point on the dose-response curve (e.g. a benchmark dose lower confidences limit derived from a rodent carcinogenicity study) divided by the estimated human intake. A small MOE indicates a higher concern than a very large MOE. Whilst the MOE cannot be directly equated to risk, it supports prioritisation of substances for further research or for possible regulatory action, and provides a basis for communicating to the public. So far, the MOE approach has been confined to substances for which carcinogenicity data are available. In the absence of carcinogenicity data, evidence of genotoxicity is used only in hazard identification. The challenge to the genetic toxicology community is to develop approaches for characterising risk to human health based on data from genotoxicity studies. In order to achieve wide acceptance, it would be important to further address the issues that have been discussed in the context of dose-response modelling of carcinogenicity data in order to assign levels of concern to particular MOE values, and also whether it is possible to make generic conclusions on how potency in genotoxicity assays relates to carcinogenic potency. © Crown copyright 2015.

Transforming Graphical System Models to Graphical Attack Models

DEFF Research Database (Denmark)

Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, Rene Rydhof

2016-01-01

Manually identifying possible attacks on an organisation is a complex undertaking; many different factors must be considered, and the resulting attack scenarios can be complex and hard to maintain as the organisation changes. System models provide a systematic representation of organisations...... approach to transforming graphical system models to graphical attack models in the form of attack trees. Based on an asset in the model, our transformations result in an attack tree that represents attacks by all possible actors in the model, after which the actor in question has obtained the asset....

QSAR ligand dataset for modelling mutagenicity, genotoxicity, and rodent carcinogenicity

Directory of Open Access Journals (Sweden)

Davy Guan

2018-04-01

Full Text Available Five datasets were constructed from ligand and bioassay result data from the literature. These datasets include bioassay results from the Ames mutagenicity assay, Greenscreen GADD-45a-GFP assay, Syrian Hamster Embryo (SHE assay, and 2 year rat carcinogenicity assay results. These datasets provide information about chemical mutagenicity, genotoxicity and carcinogenicity.

Genotoxicity evaluation of the insecticide ethion in root of Allium ...

African Journals Online (AJOL)

In this study, the genotoxic effects of ethion were investigated in the mitotic cell division of Allium cepa. Primary roots of A. cepa were treated with various concentrations (25, 50, 75, and 100%) of ethion solutions for different duration of time. The result revealed that increase in the concentration and duration of treatment ...

When Sinuses Attack! (For Kids)

Science.gov (United States)

... First Aid & Safety Doctors & Hospitals Videos Recipes for Kids Kids site Sitio para niños How the Body Works ... Search English Español When Sinuses Attack! KidsHealth / For Kids / When Sinuses Attack! What's in this article? What ...

Heart Attack

Science.gov (United States)

... properly causes your body's blood sugar levels to rise, increasing your risk of heart attack. Metabolic syndrome. This occurs when you have obesity, high blood pressure and high blood sugar. Having metabolic ...

Exogenous lipoid pneumonia after ingestion of shark liver oil: a case report

International Nuclear Information System (INIS)

Yang, Jae Bum; Seong, Hyeon Lim; Park, Chan Sup; Park, Yang Hee; Lee, Sang Sun

1991-01-01

Exogenous lipoid pneumonia was first described in 1925 by Laughlen and a sizeable literature developed, reaching a peak in the 1940s. Two cases of exogenous lipoid pneumonia in children were reported domestically. We wish to report a case of exogenous lipoid pneumonia presented with bilateral air-space consolidation in a 53-year-old man who had a long history of ingestion of shark liver oil. This report describes its radiological findings, along with a review of the literature

A tiered approach to the use of alternatives to animal testing for the safety assessment of cosmetics: genotoxicity. A COLIPA analysis.

Science.gov (United States)

Pfuhler, Stefan; Kirst, Annette; Aardema, Marilyn; Banduhn, Norbert; Goebel, Carsten; Araki, Daisuke; Costabel-Farkas, Margit; Dufour, Eric; Fautz, Rolf; Harvey, James; Hewitt, Nicola J; Hibatallah, Jalila; Carmichael, Paul; Macfarlane, Martin; Reisinger, Kerstin; Rowland, Joanna; Schellauf, Florian; Schepky, Andreas; Scheel, Julia

2010-01-01

For the assessment of genotoxic effects of cosmetic ingredients, a number of well-established and regulatory accepted in vitro assays are in place. A caveat to the use of these assays is their relatively low specificity and high rate of false or misleading positive results. Due to the 7th amendment to the EU Cosmetics Directive ban on in vivo genotoxicity testing for cosmetics that was enacted March 2009, it is no longer possible to conduct follow-up in vivo genotoxicity tests for cosmetic ingredients positive in in vitro genotoxicity tests to further assess the relevance of the in vitro findings. COLIPA, the European Cosmetics Association, has initiated a research programme to improve existing and develop new in vitro methods. A COLIPA workshop was held in Brussels in April 2008 to analyse the best possible use of available methods and approaches to enable a sound assessment of the genotoxic hazard of cosmetic ingredients. Common approaches of cosmetic companies are described, with recommendations for evaluating in vitro genotoxins using non-animal approaches. A weight of evidence approach was employed to set up a decision-tree for the integration of alternative methods into tiered testing strategies. Copyright 2010 Elsevier Inc. All rights reserved.

Software-based Microarchitectural Attacks

OpenAIRE

Gruss, Daniel

2017-01-01

Modern processors are highly optimized systems where every single cycle of computation time matters. Many optimizations depend on the data that is being processed. Software-based microarchitectural attacks exploit effects of these optimizations. Microarchitectural side-channel attacks leak secrets from cryptographic computations, from general purpose computations, or from the kernel. This leakage even persists across all common isolation boundaries, such as processes, containers, and virtual ...

Genotoxic effects of vinclozolin on the aquatic insect Chironomus riparius (Diptera, Chironomidae).

Science.gov (United States)

Aquilino, Mónica; Sánchez-Argüello, Paloma; Martínez-Guitarte, José-Luis

2018-01-01

Vinclozolin (Vz) is a pollutant found in aquatic environments whose antiandrogenic effects in reproduction are well known in mammals. Although its reproductive effects have been less studied in invertebrates, other effects, including genotoxicity, have been described. Therefore, in this work, we studied the genotoxic effects of Vz in the freshwater benthic invertebrate Chironomus riparius. DNA damage was evaluated with the comet assay (tail area, olive moment, tail moment and % DNA in tail), and the transcriptional levels of different genes involved in DNA repair (ATM, NLK and XRCC1) and apoptosis (DECAY) were measured by RT-PCR. Fourth instar larvae of C. riparius, were exposed to Vz for 24 h at 20 and 200 μg/L. The Vz exposures affected the DNA integrity in this organism, since a dose-response relationship occurred, with DNA strand breaks significantly increased with increased dose for tail area, olive moment and tail moment parameters. Additionally, the lower concentration of Vz produced a significant induction of the transcripts of three genes under study (ATM, NLK and XRCC1) showing the activation of the cellular repair mechanism. In contrast, the expression of these genes with the highest concentration were downregulated, indicating failure of the cellular repair mechanism, which would explain the higher DNA damage. These data report for the first time the alterations of Vz on gene transcription of an insect and confirm the potential genotoxicity of this compound on freshwater invertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Integrating cyber attacks within fault trees

International Nuclear Information System (INIS)

Nai Fovino, Igor; Masera, Marcelo; De Cian, Alessio

2009-01-01

In this paper, a new method for quantitative security risk assessment of complex systems is presented, combining fault-tree analysis, traditionally used in reliability analysis, with the recently introduced Attack-tree analysis, proposed for the study of malicious attack patterns. The combined use of fault trees and attack trees helps the analyst to effectively face the security challenges posed by the introduction of modern ICT technologies in the control systems of critical infrastructures. The proposed approach allows considering the interaction of malicious deliberate acts with random failures. Formal definitions of fault tree and attack tree are provided and a mathematical model for the calculation of system fault probabilities is presented.

Integrating cyber attacks within fault trees

Energy Technology Data Exchange (ETDEWEB)

Nai Fovino, Igor [Joint Research Centre - EC, Institute for the Protection and Security of the Citizen, Ispra, VA (Italy)], E-mail: igor.nai@jrc.it; Masera, Marcelo [Joint Research Centre - EC, Institute for the Protection and Security of the Citizen, Ispra, VA (Italy); De Cian, Alessio [Department of Electrical Engineering, University di Genova, Genoa (Italy)

2009-09-15

In this paper, a new method for quantitative security risk assessment of complex systems is presented, combining fault-tree analysis, traditionally used in reliability analysis, with the recently introduced Attack-tree analysis, proposed for the study of malicious attack patterns. The combined use of fault trees and attack trees helps the analyst to effectively face the security challenges posed by the introduction of modern ICT technologies in the control systems of critical infrastructures. The proposed approach allows considering the interaction of malicious deliberate acts with random failures. Formal definitions of fault tree and attack tree are provided and a mathematical model for the calculation of system fault probabilities is presented.

Attack and Vulnerability Penetration Testing: FreeBSD

Directory of Open Access Journals (Sweden)

Abdul Hanan Abdullah

2013-07-01

Full Text Available Computer system security has become a major concern over the past few years. Attacks, threasts or intrusions, against computer system and network have become commonplace events. However, there are some system devices and other tools that are available to overcome the threat of these attacks. Currently, cyber attack is a major research and inevitable. This paper presents some steps of penetration in FreeBSD operating system, some tools and new steps to attack used in this experiment, probes for reconnaissance, guessing password via brute force, gaining privilege access and flooding victim machine to decrease availability. All these attacks were executed and infiltrate within the environment of Intrusion Threat Detection Universiti Teknologi Malaysia (ITD UTM data set. This work is expected to be a reference for practitioners to prepare their systems from Internet attacks.

Function of endothelium at adolescents with constitutional exogenous obesity before and after rehabilitation

OpenAIRE

Miroshnichenko, O.

2011-01-01

Function of endothelium at 43 adolescents with constitutional exogenous obesity before rehabilitation and at 33 healthy adolescents has been studied. Disorder of endothelial function has been established in 32 (74.4%) adolescents with constitutional exogenous obesity and in 7 (21.2%) healthy adolescents. We showed the efficiency of the rehabilitation program on restoration of endothelial function at adolescents with constitutional exogenous obesity.

Superposition Attacks on Cryptographic Protocols

DEFF Research Database (Denmark)

Damgård, Ivan Bjerre; Funder, Jakob Løvstad; Nielsen, Jesper Buus

2011-01-01

of information. In this paper, we introduce a fundamentally new model of quantum attacks on classical cryptographic protocols, where the adversary is allowed to ask several classical queries in quantum superposition. This is a strictly stronger attack than the standard one, and we consider the security......Attacks on classical cryptographic protocols are usually modeled by allowing an adversary to ask queries from an oracle. Security is then defined by requiring that as long as the queries satisfy some constraint, there is some problem the adversary cannot solve, such as compute a certain piece...... of several primitives in this model. We show that a secret-sharing scheme that is secure with threshold $t$ in the standard model is secure against superposition attacks if and only if the threshold is lowered to $t/2$. We use this result to give zero-knowledge proofs for all of NP in the common reference...

Genotoxicity in earthworm after combined treatment of ionising radiation and mercury

International Nuclear Information System (INIS)

Ryu, Tae Ho; Kim, Jin Kyu; An, Kwang-Guk

2014-01-01

This study was performed to investigate the acute genotoxic effects of mercury and radiation on earthworms (Eisenia fetida). The levels of DNA damage and the repair kinetics in the coelomocytes of E. fetida treated with mercuric chloride (HgCl 2 ) and ionising radiation (gamma rays) were analysed by means of the comet assay. For detection of DNA damage and repair, E. fetida was exposed to HgCl 2 (0-160 mg kg -1 ) and irradiated with gamma rays (0-50 Gy) in vivo. The increase in DNA damage depended on the concentration of mercury or dose of radiation. The results showed that the more the oxidative stress induced by mercury and radiation the longer the repair time that was required. When a combination of HgCl 2 and gamma rays was applied, the cell damage was much higher than those treated with HgCl 2 or radiation alone, which indicated that the genotoxic effects were increased after the combined treatment of mercury and radiation. (authors)

Structure and texture of uranium ores in exogenous deposits

International Nuclear Information System (INIS)

Danchev, V.I.

1977-01-01

Structure and texture signs of uranium rock exogenous deposits have been systematized for the first time, taking into account the slaging of the ore-formation process, connected with formation and change of containing sedimentary rocks, starting with the sedimentogenesis stage and early sediment diagenesis and their subsequent transformation in katagenesis and metamorphism processes. The main features of uranium geochemistry in the exogenous process are considered. Suggested is the genetic classification of uranium exogenous deposits in rocks of sedimentary cover, made with respect to conjugation and various ore-forming productivity of the litogenesis stage. Described are the main combinations of various rock texture and structure properties, characteristic of deposits of genetic classes and groups of the above classification. Eight most frequently occuring textures (lamellar, concretion, oolitic, coagulate, crack, mixed and impregnated) and their types are described and illustrated. Materials of soviet and foreign authors have been used to compile the atlas

A method for tracing exogenous DNA uptake in live spermatozoa and embryos.

Science.gov (United States)

Mu, Y; Jiao, M; Zhao, Y; Lv, J; Wang, J; Hao, J; Zhang, X; Kong, Q; Liu, Z

2018-03-01

Sperm-mediated gene transfer(SMGT) is a simple method for producing transgenic animals. Due to the lack of repeatability in spermatozoa binding and internalization of exogenous DNA, the efficiency of SMGT is still low. Considering this point, the present work aims to develop a method for evaluating the spermatozoa capacity of binding exogenous DNA after co-incubation with DNA. The main approach is using a Cy5-labelled DNA to trace the exogenous DNA and assess the ability of spermatozoa to take up exogenous DNA. Using this technique, we found that the percentage of spermatozoa that are binding and uptaking DNA is higher at concentration of 10 μg/mL and 100 μg/mL than 5 μg/mL, 1 μg/mL and 0 μg/mL after incubation with Cy5-DNA for 30min at 37oC. After fertilization, the DNA fluorescence signal was also detected in zygotes in groups where spermatozoa were incubated with 10 μg/mL and 100 μg/mL of Cy5-DNA. These results showed a simple and convenient method to trace the exogenous DNA in spermatozoa and zygote when compared to conventional methods of labeling DNA during fertilization, resulting in a real-time observation of the exogenous DNA in spermatozoa and zygote. Copyright© by the Polish Academy of Sciences.

Recurrent spontaneous attacks of dizziness.

Science.gov (United States)

Lempert, Thomas

2012-10-01

This article describes the common causes of recurrent vertigo and dizziness that can be diagnosed largely on the basis of history. Ninety percent of spontaneous recurrent vertigo and dizziness can be explained by six disorders: (1) Ménière disease is characterized by vertigo attacks, lasting 20 minutes to several hours, with concomitant hearing loss, tinnitus, and aural fullness. Aural symptoms become permanent during the course of the disease. (2) Attacks of vestibular migraine may last anywhere from minutes to days. Most patients have a previous history of migraine headaches, and many experience migraine symptoms during the attack. (3) Vertebrobasilar TIAs affect older adults with vascular risk factors. Most attacks last less than 1 hour and are accompanied by other symptoms from the posterior circulation territory. (4) Vestibular paroxysmia is caused by vascular compression of the eighth cranial nerve. It manifests itself with brief attacks of vertigo that recur many times per day, sometimes with concomitant cochlear symptoms. (5) Orthostatic hypotension causes brief episodes of dizziness lasting seconds to a few minutes after standing up and is relieved by sitting or lying down. In older adults, it may be accompanied by supine hypertension. (6) Panic attacks usually last minutes, occur in specific situations, and are accompanied by choking, palpitations, tremor, heat, and anxiety. Less common causes of spontaneous recurrent vertigo and dizziness include perilymph fistula, superior canal dehiscence, autoimmune inner ear disease, otosclerosis, cardiac arrhythmia, and medication side effects. Neurologists need to venture into otolaryngology, internal medicine, and psychiatry to master the differential diagnosis of recurrent dizziness.

Genotoxic action of sunlight upon Bacillus subtilis spores

International Nuclear Information System (INIS)

Munakata, Nobuo

1989-01-01

Samples of Bacillus subtilis spores dried on membrane filter were exposed to natural sunlight from solar-noon time at Tokyo. The survival and mutation induction of wild-type (UVR) and repair-deficient (UVS) spores were determined on 66 occasions since 1979. Two of the values were considered to be useful in monitoring solar UV intensity; the inverse of the time (in minutes) of exposure to kill 63% of the UVS spores ('sporocidal index') and the induced mutation frequency at 60 minutes of exposure of the UVR spores ('mutagenic index'). Both values were varied greatly due to time of a year, weather and other conditions. Estimates of year-round changes under clear skies were obtained by connecting the maximum values attained in these years. In these curves, there are more than 7-fold differences in the genotoxicity between winter and summer months, with major increases observed in early spring and decreases through autumn. Using a series of UV cut-off filters, the wavelengths most effective for the sporocidal actions were estimated to be in the range of 308 - 325 nm, shorter wavelengths being effective when the genotoxicity was higher. Sunburn meter of Robertson-Berger type seems to respond to slightly longer wavelength components of the solar spectrum. However, a reasonable correlation was obtained between the reading of the meter and the sporocidal index. (author)

Identification of early target genes of aflatoxin B1 in human hepatocytes, inter-individual variability and comparison with other genotoxic compounds

International Nuclear Information System (INIS)

Josse, Rozenn; Dumont, Julie; Fautrel, Alain; Robin, Marie-Anne; Guillouzo, André

2012-01-01

Gene expression profiling has recently emerged as a promising approach to identify early target genes and discriminate genotoxic carcinogens from non-genotoxic carcinogens and non-carcinogens. However, early gene changes induced by genotoxic compounds in human liver remain largely unknown. Primary human hepatocytes and differentiated HepaRG cells were exposed to aflatoxin B1 (AFB1) that induces DNA damage following enzyme-mediated bioactivation. Gene expression profile changes induced by a 24 h exposure of these hepatocyte models to 0.05 and 0.25 μM AFB1 were analyzed by using oligonucleotide pangenomic microarrays. The main altered signaling pathway was the p53 pathway and related functions such as cell cycle, apoptosis and DNA repair. Direct involvement of the p53 protein in response to AFB1 was verified by using siRNA directed against p53. Among the 83 well-annotated genes commonly modulated in two pools of three human hepatocyte populations and HepaRG cells, several genes were identified as altered by AFB1 for the first time. In addition, a subset of 10 AFB1-altered genes, selected upon basis of their function or tumor suppressor role, was tested in four human hepatocyte populations and in response to other chemicals. Although they exhibited large variable inter-donor fold-changes, several of these genes, particularly FHIT, BCAS3 and SMYD3, were found to be altered by various direct and other indirect genotoxic compounds and unaffected by non-genotoxic compounds. Overall, this comprehensive analysis of early gene expression changes induced by AFB1 in human hepatocytes identified a gene subset that included several genes representing potential biomarkers of genotoxic compounds. -- Highlights: ► Gene expression profile changes induced by aflatoxin B1 in human hepatocytes. ► AFB1 modulates various genes including tumor suppressor genes and proto-oncogenes. ► Important inter-individual variations in the response to AFB1. ► Some genes also altered by other

Shark Attack Project - Marine Attack at Towed Hydrophone Arrays

National Research Council Canada - National Science Library

Kalmijn, Adrianus J

2005-01-01

The original objective of the SIO Marine Attack project was to identify the electric and magnetic fields causing sharks to inflict serious damage upon the towed hydrophone arrays of US Navy submarines...

Novel Method For Low-Rate Ddos Attack Detection

Science.gov (United States)

Chistokhodova, A. A.; Sidorov, I. D.

2018-05-01

The relevance of the work is associated with an increasing number of advanced types of DDoS attacks, in particular, low-rate HTTP-flood. Last year, the power and complexity of such attacks increased significantly. The article is devoted to the analysis of DDoS attacks detecting methods and their modifications with the purpose of increasing the accuracy of DDoS attack detection. The article details low-rate attacks features in comparison with conventional DDoS attacks. During the analysis, significant shortcomings of the available method for detecting low-rate DDoS attacks were found. Thus, the result of the study is an informal description of a new method for detecting low-rate denial-of-service attacks. The architecture of the stand for approbation of the method is developed. At the current stage of the study, it is possible to improve the efficiency of an already existing method by using a classifier with memory, as well as additional information.

Decisions to regulate genotoxic substances

Energy Technology Data Exchange (ETDEWEB)

Bengtsson, G

1988-07-01

Decisions to regulate genotoxic substances involve trade-offs between various incomparable factors such as risks to human health and other environmental risks, public perceptions, costs and uncertainties. Two different approaches towards these trade-offs are discussed. In one approach, all relevant factors are defined and trade-offs are considered using a general and very elaborate analysis. Cost-benefit analysis is an exponent of this approach. An illustration is given for the regulation of transboundary releases of radioactive materials. The other approach considers what is politically feasible for the time being and seeks a decision with much room for later corrections. Incrementalism is a philosophy in this vein. It is illustrated by reference to the regulation of transboundary air pollution. Weaknesses and strengths of the two approaches are discussed. (author)

Decisions to regulate genotoxic substances

International Nuclear Information System (INIS)

Bengtsson, G.

1988-01-01

Decisions to regulate genotoxic substances involve trade-offs between various incomparable factors such as risks to human health and other environmental risks, public perceptions, costs and uncertainties. Two different approaches towards these trade-offs are discussed. In one approach, all relevant factors are defined and trade-offs are considered using a general and very elaborate analysis. Cost-benefit analysis is an exponent of this approach. An illustration is given for the regulation of transboundary releases of radioactive materials. The other approach considers what is politically feasible for the time being and seeks a decision with much room for later corrections. Incrementalism is a philosophy in this vein. It is illustrated by reference to the regulation of transboundary air pollution. Weaknesses and strengths of the two approaches are discussed. (author)

Genotoxic activities of the food contaminant 5-hydroxymethylfurfural using different in vitro bioassays.

Science.gov (United States)

Severin, Isabelle; Dumont, Coralie; Jondeau-Cabaton, Adeline; Graillot, Vanessa; Chagnon, Marie-Christine

2010-02-01

5-Hydroxymethylfurfural (5-HMF) is known as an indicator of quality deterioration in a wide range of foods. 5-HMF is formed as an intermediate in the Maillard reaction and has been identified in a wide variety of heat-processed foods. In recent years, the presence of 5-HMF in foods has raised toxicological concerns: data have shown cytotoxic, genotoxic and tumoral effects but further studies suggest that 5-HMF does not pose a serious health risk. However the subject is still a matter of debate. We investigated the genotoxicity of the food-borne contaminant 5-HMF using the Ames test, the micronucleus (MN) and the single-cell gel electrophoresis (SCGE) assays in the human metabolically active HepG2 cell line. Cytotoxic effect of 5-HMF was first assessed using Alamar Blue as a sensitive sub-lethal assay. 5-HMF did not induce any genic mutation in bacteria whatever the concentration in the Ames test. Furthermore, it does not induce clastogenic or aneugenic effects in the HepG2 cells. In contrast, 5-HMF induced HepG2 DNA damage at concentrations from 7.87 to 25 mM in the comet assay suggesting a weak genotoxic effect of 5-HMF in the HepG2 cells probably repaired. 2009 Elsevier Ireland Ltd. All rights reserved.

High-throughput in vivo genotoxicity testing: an automated readout system for the somatic mutation and recombination test (SMART.

Directory of Open Access Journals (Sweden)

Benoit Lombardot

Full Text Available Genotoxicity testing is an important component of toxicity assessment. As illustrated by the European registration, evaluation, authorization, and restriction of chemicals (REACH directive, it concerns all the chemicals used in industry. The commonly used in vivo mammalian tests appear to be ill adapted to tackle the large compound sets involved, due to throughput, cost, and ethical issues. The somatic mutation and recombination test (SMART represents a more scalable alternative, since it uses Drosophila, which develops faster and requires less infrastructure. Despite these advantages, the manual scoring of the hairs on Drosophila wings required for the SMART limits its usage. To overcome this limitation, we have developed an automated SMART readout. It consists of automated imaging, followed by an image analysis pipeline that measures individual wing genotoxicity scores. Finally, we have developed a wing score-based dose-dependency approach that can provide genotoxicity profiles. We have validated our method using 6 compounds, obtaining profiles almost identical to those obtained from manual measures, even for low-genotoxicity compounds such as urethane. The automated SMART, with its faster and more reliable readout, fulfills the need for a high-throughput in vivo test. The flexible imaging strategy we describe and the analysis tools we provide should facilitate the optimization and dissemination of our methods.

Evaluation of genotoxic effects caused by extracts of chlorinated drinking water using a combination of three different bioassays.

Science.gov (United States)

Zeng, Qiang; Zhang, Shao-Hui; Liao, Jing; Miao, Dong-Yue; Wang, Xin-Yi; Yang, Pan; Yun, Luo-Jia; Liu, Ai-Lin; Lu, Wen-Qing

2015-10-15

Potential genotoxic effects of chlorinated drinking water now are of a great concern. In this study, raw water, finished water, and tap water from a water plant in Wuhan, China were collected in two different sampling times of the year (January and July). Genotoxic effects of water extracts were evaluated using a combination of three different bioassays: SOS/umu test, HGPRT gene mutation assay, and micronucleus assay, which were separately used to detect DNA damage, gene mutation, and chromosome aberration. The results of three different bioassays showed that all water samples in January and July induced at least one types of genotoxic effects, of which the DNA-damage effects were all detectable. The levels of DNA-damage effects and gene-mutation effects of finished water and tap water in January were higher than those in July. Chlorination could increase the DNA-damage effects of drinking water in January and the gene-mutation effects of drinking water in both January and July, but did not increase the chromosome-aberration effects of drinking water in both January and July. Our results highlighted the importance of using a combination of different bioassays to evaluate the genotoxicity of water samples in different seasons. Copyright © 2015 Elsevier B.V. All rights reserved.

Heart Attack

Science.gov (United States)

... family history of heart attack race – African Americans, Mexican Americans, Native Americans, and native Hawaiians are at ... Your doctor will prescribe the medicines that are right for you. If you have had a heart ...

Genotoxic effects and oxidative stress induced by organic extracts of particulate matter(PM 10)collected from a subway tunnel in Seoul, Korea.

Science.gov (United States)

Jung, Mi Hyun; Kim, Ha Ryong; Park, Yong Joo; Park, Duck Shin; Chung, Kyu Hyuck; Oh, Seung Min

2012-12-12

Particulate matter (PM) has become an important health risk factor in our society. PM can easily deposit in the bronchi and lungs, causing diverse diseases such as respiratory infections, lung cancers and cardiovascular diseases. In recent days, more and more toxicological studies have been dealing with air particles in distinctive areas including industrial areas, transportation sites, or indoors. Studies on subway PM in particular, have been recognizing PM as an important health risk factor because many people use subways as a major mode of public transportation (4 million people a day in Korea). The main aim of the present study was to evaluate the genotoxic effects of organic extract (OE) of subway PM10 and potential attribution of PAHs to these effects. Particles were collected in the subway tunnel at Kil-eum station(Line 4) for one month and then extracted with Dichloromethane (DCM). Chinese Hamster Ovary cells(CHO-K1) and human normal bronchial cells (BEAS-2B) were exposed to OE, and MN and Comet assays were conducted to analyze the genotoxicity. The results showed that OE increased DNA or chromosome damages in both cell lines. In the modified Comet assay and MN assay with free radical scavengers, we confirmed that the genotoxic effect of OE was partially due to the oxidative damage on DNA. DCFHD Aassay also indicated that OE induced ROS generation in BEAS-2B cells. PAHs [benzo(a)anthracene,benzo(k)fluoranthrene, etc.], the most well-known carcinogens in polluted air, were detected in Kil-eum PM10. In conclusion, our findings confirmed that OE of subway PM10 has genotoxic effects on normal human lung cells, and oxidative stress could be one of the major mechanisms of these genotoxic effects.In addition, some genotoxic and carcinogenic PAHs were detected in OE by GC/MS/MS, even though PAHs level was not enough to increase CYP1A1 gene. Therefore, we suggest that additive or synergistic effects by unidentified chemicals as well as PAHs contained in OE of subway

Automatic Classification of Attacks on IP Telephony

Directory of Open Access Journals (Sweden)

Jakub Safarik

2013-01-01

Full Text Available This article proposes an algorithm for automatic analysis of attack data in IP telephony network with a neural network. Data for the analysis is gathered from variable monitoring application running in the network. These monitoring systems are a typical part of nowadays network. Information from them is usually used after attack. It is possible to use an automatic classification of IP telephony attacks for nearly real-time classification and counter attack or mitigation of potential attacks. The classification use proposed neural network, and the article covers design of a neural network and its practical implementation. It contains also methods for neural network learning and data gathering functions from honeypot application.

Further attacks on Yeung-Mintzer fragile watermarking scheme

Science.gov (United States)

Fridrich, Jessica; Goljan, Miroslav; Memon, Nasir D.

2000-05-01

In this paper, we describe new and improved attacks on the authentication scheme previously proposed by Yeung and Mintzer. Previous attacks assumed that the binary watermark logo inserted in an image for the purposes of authentication was known. Here we remove that assumption and show how the scheme is still vulnerable, even if the binary logo is not known but the attacker has access to multiple images that have been watermarked with the same secret key and contain the same (but unknown) logo. We present two attacks. The first attack infers the secret watermark insertion function and the binary logo, given multiple images authenticated with the same key and containing the same logo. We show that a very good approximation to the logo and watermark insertion function can be constructed using as few as two images. With color images, one needs many more images, nevertheless the attack is still feasible. The second attack we present, which we call the 'collage-attack' is a variation of the Holliman-Memon counterfeiting attack. The proposed variation does not require knowledge of the watermark logo and produces counterfeits of superior quality by means of a suitable dithering process that we develop.

Pareto Efficient Solution of Attack-Defence Trees

NARCIS (Netherlands)

Aslanyan, Zaruhi; Nielson, Flemming

Attack-defence trees are a promising approach for representing threat scenarios and possible countermeasures in a concise and intuitive manner. An attack-defence tree describes the interaction between an attacker and a defender, and is evaluated by assigning parameters to the nodes, such as

The comet assay in testing the potential genotoxicity of nanomaterials

Directory of Open Access Journals (Sweden)

Amaya Azqueta

2015-06-01

Full Text Available In the last two decades the production and use of nanomaterials (NMs has impressively increased. Their small size, given a mass equal to that of the corresponding bulk material, implies an increase in the surface area and consequently in the number of atoms that can be reactive. They possess different physical, chemical and biological properties compared to bulk materials of the same composition, which makes them very interesting and valuable for many different applications in technology, energy, construction, electronics, agriculture, optics, paints, textiles, food, cosmetics, medicine... Toxicological assessment of NMs is crucial; the same properties that make them interesting also make them potentially harmful for health and the environment. However, the term NM covers many different kinds of particle , and so there is no simple, standard approach to assessing their toxicity. NMs can enter the cell, interact with cell components and even penetrate the nucleus and interfere with the genetic material. Among the different branches of toxicology, genotoxicity is a main area of concern since it is closely related with the carcinogenic potential of compounds. The Organisation for Economic Co-operation and Development (OECD has published internationally agreed in vitro and in vivo validated test methods to evaluate different genotoxic endpoints of chemicals, including chromosome and gene mutations, and DNA breaks. However not all the assays are suitable to study the genotoxic potential of NMs as has been shown by the OECD Working Party on Manufactured Nanomaterials (WPMN. Moreover, alterations to DNA bases, which are precursors to mutations and of great importance in elucidating the mechanism of action of NMs, are not covered by the OECD guidelines. The in vivo standard comet assay (which measures DNA breaks and alkali-labile sites was included in the OECD assays battery in September 2014 while the in vitro standard comet assay is currently under

Differences between endogenous and exogenous emotion inhibition in the human brain.

Science.gov (United States)

Kühn, Simone; Haggard, Patrick; Brass, Marcel

2014-05-01

The regulation of emotions is an integral part of our mental health. It has only recently been investigated using brain imaging techniques. In most studies, participants are instructed by a cue to inhibit a specific emotional reaction. The aim of the present study was to investigate the alternative situation where a person decides to inhibit an emotion as an act of endogenous self-control. Healthy participants viewed highly arousing pictures with negative valence. In the endogenous condition, participants could freely choose on each trial to inhibit or feel the emotions elicited by the picture. In an exogenous condition, a visual cue instructed them to either feel or inhibit the emotion elicited by the picture. Participants' subjective ratings of intensity of experienced emotion showed an interaction effect between source of control (endogenous/exogenous) and feel/inhibit based on a stronger modulation between feel and inhibition for the endogenous compared to the exogenous condition. Endogenous inhibition of emotions was associated with dorso-medial prefrontal cortex activation, whereas exogenous inhibition was found associated with lateral prefrontal cortex activation. Thus, the brain regions for both endogenous and exogenous inhibition of emotion are highly similar to those for inhibition of motor actions in Brass and Haggard (J Neurosci 27:9141-9145, 2007), Kühn et al. (Hum Brain Mapp 30:2834-2843, 2009). Functional connectivity analyses showed that dorsofrontomedial cortex exerts greater control onto pre-supplementary motor area during endogenous inhibition compared to endogenous feel. This functional dissociation between an endogenous, fronto-medial and an exogenous, fronto-lateral inhibition centre has important implications for our understanding of emotion regulation in health and psychopathology.

Genotoxicity assessment of membrane concentrates of landfill leachate treated with Fenton reagent and UV-Fenton reagent using human hepatoma cell line

Energy Technology Data Exchange (ETDEWEB)

Wang, Guifang [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Lu, Gang [Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation of Guangdong Higher Education Institutes, Department of Environmental Engineering, Jinan University, Guangzhou 510632 (China); Yin, Pinghe, E-mail: tyinph@jnu.edu.cn [Research Center of Analysis and Test, Jinan University, Guangzhou 510632 (China); Zhao, Ling, E-mail: zhaoling@jnu.edu.cn [Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation of Guangdong Higher Education Institutes, Department of Environmental Engineering, Jinan University, Guangzhou 510632 (China); Jimmy Yu, Qiming [Griffith School of Engineering, Griffith University, Nathan Campus, Brisbane, Queensland 4111 (Australia)

2016-04-15

Highlights: • Membrane concentrates have a threat to human health and environment. • Untreated membrane concentrates induces cytotoxic and genotoxic to HepG2 cells. • Both methods were effective method for degradation of BPA and NP in concentrates. • Both methods were efficient in reducing genotoxic effects of concentrates. • UV-Fenton reagent had higher removal efficiency and provides toxicological safety. - Abstract: Membrane concentrates of landfill leachates contain organic and inorganic contaminants that could be highly toxic and carcinogenic. In this paper, the genotoxicity of membrane concentrates before and after Fenton and UV-Fenton reagent was assessed. The cytotoxicity and genotoxicity was determined by using the methods of methyltetrazolium (MTT), cytokinesis-block micronucleus (CBMN) and comet assay in human hepatoma cells. MTT assay showed a cytotoxicity of 75% after 24 h of exposure to the highest tested concentration of untreated concentrates, and no cytotoxocity for UV-Fenton and Fenton treated concentrates. Both CBMN and comet assays showed increased levels of genotoxicity in cells exposed to untreated concentrates, compared to those occurred in cells exposed to UV-Fenton and Fenton reagent treated concentrates. There was no significant difference between negative control and UV-Fenton treated concentrates for micronucleus and comet assay parameters. UV-Fenton and Fenton treatment, especially the former, were effective methods for degradation of bisphenol A and nonylphenol in concentrates. These findings showed UV-Fenton and Fenton reaction were effective methods for treatment of such complex concentrates, UV-Fenton reagent provided toxicological safety of the treated effluent, and the genotoxicity assays were found to be feasible tools for assessment of toxicity risks of complex concentrates.

Genotoxicity assessment of membrane concentrates of landfill leachate treated with Fenton reagent and UV-Fenton reagent using human hepatoma cell line

International Nuclear Information System (INIS)

Wang, Guifang; Lu, Gang; Yin, Pinghe; Zhao, Ling; Jimmy Yu, Qiming

2016-01-01

Highlights: • Membrane concentrates have a threat to human health and environment. • Untreated membrane concentrates induces cytotoxic and genotoxic to HepG2 cells. • Both methods were effective method for degradation of BPA and NP in concentrates. • Both methods were efficient in reducing genotoxic effects of concentrates. • UV-Fenton reagent had higher removal efficiency and provides toxicological safety. - Abstract: Membrane concentrates of landfill leachates contain organic and inorganic contaminants that could be highly toxic and carcinogenic. In this paper, the genotoxicity of membrane concentrates before and after Fenton and UV-Fenton reagent was assessed. The cytotoxicity and genotoxicity was determined by using the methods of methyltetrazolium (MTT), cytokinesis-block micronucleus (CBMN) and comet assay in human hepatoma cells. MTT assay showed a cytotoxicity of 75% after 24 h of exposure to the highest tested concentration of untreated concentrates, and no cytotoxocity for UV-Fenton and Fenton treated concentrates. Both CBMN and comet assays showed increased levels of genotoxicity in cells exposed to untreated concentrates, compared to those occurred in cells exposed to UV-Fenton and Fenton reagent treated concentrates. There was no significant difference between negative control and UV-Fenton treated concentrates for micronucleus and comet assay parameters. UV-Fenton and Fenton treatment, especially the former, were effective methods for degradation of bisphenol A and nonylphenol in concentrates. These findings showed UV-Fenton and Fenton reaction were effective methods for treatment of such complex concentrates, UV-Fenton reagent provided toxicological safety of the treated effluent, and the genotoxicity assays were found to be feasible tools for assessment of toxicity risks of complex concentrates.

Hexavalent Chromium Is Cytotoxic and Genotoxic to Hawksbill Sea Turtle Cells

Science.gov (United States)

Wise, Sandra S.; Xie, Hong; Fukuda, Tomokazu; Thompson, W. Douglas; Wise, John Pierce

2014-01-01

Sea turtles are a charismatic and ancient ocean species and can serve as key indicators for ocean ecosystems, including coral reefs and sea grass beds as well as coastal beaches. Genotoxicity studies in the species are absent, limiting our understanding of the impact of environmental toxicants on sea turtles. Hexavalent chromium (Cr(VI)) is a ubiquitous environmental problem worldwide, and recent studies show it is a global marine pollutant of concern. Thus, we evaluated the cytotoxicity and genotoxicity of soluble and particulate Cr(VI) in hawksbill sea turtle cells. Particulate Cr(VI) was both cytotoxic and genotoxic to sea turtle cells. Concentrations of 0.1, 0.5, 1, and 5 μg/cm2 lead chromate induced 108, 79, 54, and 7 percent relative survival, respectively. Additionally, concentrations of 0, 0.1, 0.5, 1, and 5 μg/cm2 lead chromate induced damage in 4, 10, 15, 26, and 36 percent of cells and caused 4, 11, 17, 30, and 56 chromosome aberrations in 100 metaphases, respectively. For soluble Cr, concentrations of 0.25, 0.5, 1, 2.5, and 5 μM sodium chromate induced 84, 69, 46, 25, and 3 percent relative survival, respectively. Sodium chromate induced 3, 9, 9, 14, 21, and 29 percent of metaphases with damage, and caused 3, 10, 10, 16, 26, and 39 damaged chromosomes in 100 metaphases at concentrations of 0, 0.25, 0.5, 1, 2.5, and 5 μM sodium chromate, respectively. These data suggest that Cr(VI) may be a concern for hawksbill sea turtles and sea turtles in general. PMID:24952338

Elongator Plays a Positive Role in Exogenous NAD-Induced Defense Responses in Arabidopsis.

Science.gov (United States)

An, Chuanfu; Ding, Yezhang; Zhang, Xudong; Wang, Chenggang; Mou, Zhonglin

2016-05-01

Extracellular NAD is emerging as an important signal molecule in animal cells, but its role in plants has not been well-established. Although it has been shown that exogenous NAD(+) activates defense responses in Arabidopsis, components in the exogenous NAD(+)-activated defense pathway remain to be fully discovered. In a genetic screen for mutants insensitive to exogenous NAD(+) (ien), we isolated a mutant named ien2. Map-based cloning revealed that IEN2 encodes ELONGATA3 (ELO3)/AtELP3, a subunit of the Arabidopsis Elongator complex, which functions in multiple biological processes, including histone modification, DNA (de)methylation, and transfer RNA modification. Mutations in the ELO3/AtELP3 gene compromise exogenous NAD(+)-induced expression of pathogenesis-related (PR) genes and resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola ES4326, and transgenic expression of the coding region of ELO3/AtELP3 in elo3/Atelp3 restores NAD(+) responsiveness to the mutant plants, demonstrating that ELO3/AtELP3 is required for exogenous NAD(+)-induced defense responses. Furthermore, mutations in genes encoding the other five Arabidopsis Elongator subunits (ELO2/AtELP1, AtELP2, ELO1/AtELP4, AtELP5, and AtELP6) also compromise exogenous NAD(+)-induced PR gene expression and resistance to P. syringae pv. maculicola ES4326. These results indicate that the Elongator complex functions as a whole in exogenous NAD(+)-activated defense signaling in Arabidopsis.

Genetic attack on neural cryptography.

Science.gov (United States)

Ruttor, Andreas; Kinzel, Wolfgang; Naeh, Rivka; Kanter, Ido

2006-03-01

Different scaling properties for the complexity of bidirectional synchronization and unidirectional learning are essential for the security of neural cryptography. Incrementing the synaptic depth of the networks increases the synchronization time only polynomially, but the success of the geometric attack is reduced exponentially and it clearly fails in the limit of infinite synaptic depth. This method is improved by adding a genetic algorithm, which selects the fittest neural networks. The probability of a successful genetic attack is calculated for different model parameters using numerical simulations. The results show that scaling laws observed in the case of other attacks hold for the improved algorithm, too. The number of networks needed for an effective attack grows exponentially with increasing synaptic depth. In addition, finite-size effects caused by Hebbian and anti-Hebbian learning are analyzed. These learning rules converge to the random walk rule if the synaptic depth is small compared to the square root of the system size.

Genetic attack on neural cryptography

International Nuclear Information System (INIS)

Ruttor, Andreas; Kinzel, Wolfgang; Naeh, Rivka; Kanter, Ido

2006-01-01

Different scaling properties for the complexity of bidirectional synchronization and unidirectional learning are essential for the security of neural cryptography. Incrementing the synaptic depth of the networks increases the synchronization time only polynomially, but the success of the geometric attack is reduced exponentially and it clearly fails in the limit of infinite synaptic depth. This method is improved by adding a genetic algorithm, which selects the fittest neural networks. The probability of a successful genetic attack is calculated for different model parameters using numerical simulations. The results show that scaling laws observed in the case of other attacks hold for the improved algorithm, too. The number of networks needed for an effective attack grows exponentially with increasing synaptic depth. In addition, finite-size effects caused by Hebbian and anti-Hebbian learning are analyzed. These learning rules converge to the random walk rule if the synaptic depth is small compared to the square root of the system size

Genetic attack on neural cryptography

Science.gov (United States)

Ruttor, Andreas; Kinzel, Wolfgang; Naeh, Rivka; Kanter, Ido

2006-03-01

Different scaling properties for the complexity of bidirectional synchronization and unidirectional learning are essential for the security of neural cryptography. Incrementing the synaptic depth of the networks increases the synchronization time only polynomially, but the success of the geometric attack is reduced exponentially and it clearly fails in the limit of infinite synaptic depth. This method is improved by adding a genetic algorithm, which selects the fittest neural networks. The probability of a successful genetic attack is calculated for different model parameters using numerical simulations. The results show that scaling laws observed in the case of other attacks hold for the improved algorithm, too. The number of networks needed for an effective attack grows exponentially with increasing synaptic depth. In addition, finite-size effects caused by Hebbian and anti-Hebbian learning are analyzed. These learning rules converge to the random walk rule if the synaptic depth is small compared to the square root of the system size.

Analysis of Aloe vera cytotoxicity and genotoxicity associated with endodontic medication and laser photobiomodulation.

Science.gov (United States)

Carvalho, Nayane Chagas; Guedes, Simone Alves Garcez; Albuquerque-Júnior, Ricardo Luiz Cavalcanti; de Albuquerque, Diana Santana; de Souza Araújo, Adriano Antunes; Paranhos, Luiz Renato; Camargo, Samira Esteves Afonso; Ribeiro, Maria Amália Gonzaga

2018-01-01

This study aims to evaluate, in vitro, the effect of Aloe vera associated with endodontic medication, with or without laser photobiomodulation (FTL) irradiation in FP6 human pulp fibroblasts. The materials were divided into eight groups: CTR - control; CL - FTL alone; AA - Aloe vera with distilled water; AL - Aloe vera with distilled water and FTL; HA - calcium hydroxide P.A. with distilled water; HL - calcium hydroxide P.A. with distilled water and FTL; HAA - calcium hydroxide P.A. with Aloe vera and distilled water; HAL - calcium hydroxide P.A. with Aloe vera, distilled water, and FTL. The cytotoxicity was evaluated by MTT assay at 24, 48, and 72h and the genotoxicity by micronucleus test assay. This study was performed in triplicate. Data obtained in both tests were statistically analyzed by ANOVA and Tukey's tests (p≤0.05). Group AA presented high genotoxicity and low cytotoxicity. After 24, 48, and 72h, the group HAA significantly reduced the cell viability. Interaction with FTL showed slightly increase cell viability after 24 and 48h in groups CL and HL (pAloe vera allowed higher cell viability in human pulp fibroblasts in the presence of calcium hydroxide or with FTL separately, but genotoxicity increased in these associations. Copyright © 2017 Elsevier B.V. All rights reserved.

Attacks on the AJPS Mersenne-based cryptosystem

NARCIS (Netherlands)

K. de Boer (Koen); L. Ducas (Léo); S. Jeffery (Stacey); R. M. de Wolf (Ronald)

2018-01-01

textabstractAggarwal, Joux, Prakash and Santha recently introduced a new potentially quantum-safe public-key cryptosystem, and suggested that a brute-force attack is essentially optimal against it. They consider but then dismiss both Meet-in-the-Middle attacks and LLL-based attacks. Very soon after

The political attack ad

Directory of Open Access Journals (Sweden)

Palma Peña-Jiménez, Ph.D.

2011-01-01

Full Text Available During election campaigns the political spot has a clear objective: to win votes. This message is communicated to the electorate through television and Internet, and usually presents a negative approach, which includes a direct critical message against the opponent, rather than an exposition of proposals. This article is focused on the analysis of the campaign attack video ad purposely created to encourage the disapproval of the political opponent among voters. These ads focus on discrediting the opponent, many times, through the transmission of ad hominem messages, instead of disseminating the potential of the political party and the virtues and manifesto of its candidate. The article reviews the development of the attack ad since its first appearance, which in Spain dates back to 1996, when the famous Doberman ad was broadcast, and examines the most memorable campaign attack ads.

Robust Detection of Stepping-Stone Attacks

National Research Council Canada - National Science Library

He, Ting; Tong, Lang

2006-01-01

The detection of encrypted stepping-stone attack is considered. Besides encryption and padding, the attacker is capable of inserting chaff packets and perturbing packet timing and transmission order...

A Framework for Attack-Resilient Industrial Control Systems : Attack Detection and Controller Reconfiguration

OpenAIRE

Paridari, Kaveh; O'Mahony, Niamh; Mady, Alie El-Din; Chabukswar, Rohan; Boubekeur, Menouer; Sandberg, Henrik

2017-01-01

Most existing industrial control systems (ICSs), such as building energy management systems (EMSs), were installed when potential security threats were only physical. With advances in connectivity, ICSs are now, typically, connected to communications networks and, as a result, can be accessed remotely. This extends the attack surface to include the potential for sophisticated cyber attacks, which can adversely impact ICS operation, resulting in service interruption, equipment damage, safety c...

Epigenetic alterations induced by genotoxic occupational and environmental human chemical carcinogens: A systematic literature review

Science.gov (United States)

Chappell, Grace; Pogribny, Igor P.; Guyton, Kathryn Z.; Rusyn, Ivan

2016-01-01

Accumulating evidence suggests that epigenetic alterations play an important role in chemically-induced carcinogenesis. Although the epigenome and genome may be equally important in carcinogenicity, the genotoxicity of chemical agents and exposure-related transcriptomic responses have been more thoroughly studied and characterized. To better understand the evidence for epigenetic alterations of human carcinogens, and the potential association with genotoxic endpoints, we conducted a systematic review of published studies of genotoxic carcinogens that reported epigenetic endpoints. Specifically, we searched for publications reporting epigenetic effects for the 28 agents and occupations included in Monograph Volume 100F of the International Agency for the Research on Cancer (IARC) that were classified as “carcinogenic to humans” (Group 1) with strong evidence of genotoxic mechanisms of carcinogenesis. We identified a total of 158 studies that evaluated epigenetic alterations for 12 of these 28 carcinogenic agents and occupations (1,3-butadiene, 4-aminobiphenyl, aflatoxins, benzene, benzidine, benzo[a]pyrene, coke production, formaldehyde, occupational exposure as a painter, sulfur mustard, and vinyl chloride). Aberrant DNA methylation was most commonly studied, followed by altered expression of non-coding RNAs and histone changes (totaling 85, 59 and 25 studies, respectively). For 3 carcinogens (aflatoxins, benzene and benzo[a]pyrene), 10 or more studies reported epigenetic effects. However, epigenetic studies were sparse for the remaining 9 carcinogens; for 4 agents, only 1 or 2 published reports were identified. While further research is needed to better identify carcinogenesis-associated epigenetic perturbations for many potential carcinogens, published reports on specific epigenetic endpoints can be systematically identified and increasingly incorporated in cancer hazard assessments. PMID:27234561

Cyto- and genotoxic profile of groundwater used as drinking water supply before and after disinfection.

Science.gov (United States)

Pellacani, C; Cassoni, F; Bocchi, C; Martino, A; Pinto, G; Fontana, F; Furlini, M; Buschini, A

2016-12-01

The assessment of the toxicological properties of raw groundwater may be useful to predict the type and quality of tap water. Contaminants in groundwater are known to be able to affect the disinfection process, resulting in the formation of substances that are cytotoxic and/or genotoxic. Though the European directive (98/83/EC, which establishes maximum levels for contaminants in raw water (RW)) provides threshold levels for acute exposure to toxic compounds, the law does not take into account chronic exposure at low doses of pollutants present in complex mixture. The purpose of this study was to evaluate the cyto- and genotoxic load in the groundwater of two water treatment plants in Northern Italy. Water samples induced cytotoxic effects, mainly observed when human cells were treated with RW. Moreover, results indicated that the disinfection process reduced cell toxicity, independent of the biocidal used. The induction of genotoxic effects was found, in particular, when the micronucleus assay was carried out on raw groundwater. These results suggest that it is important to include bio-toxicological assays as additional parameters in water quality monitoring programs, as their use would allow the evaluation of the potential risk of groundwater for humans.

The use of genotoxicity biomarkers in molecular epidemiology: applications in environmental, occupational and dietary studies

Directory of Open Access Journals (Sweden)

Carina Ladeira

2017-08-01

Full Text Available Molecular epidemiology is an approach increasingly used in the establishment of associations between exposure to hazardous substances and development of disease, including the possible modulation by genetic susceptibility factors. Environmental chemicals and contaminants from anthropogenic pollution of air, water and soil, but also originating specifically in occupational contexts, are potential sources of risk of development of disease. Also, diet presents an important role in this process, with some well characterized associations existing between nutrition and some types of cancer. Genotoxicity biomarkers allow the detection of early effects that result from the interaction between the individual and the environment; they are therefore important tools in cancer epidemiology and are extensively used in human biomonitoring studies. This work intends to give an overview of the potential for genotoxic effects assessment, specifically with the cytokinesis blocked micronucleus assay and comet assay in environmental and occupational scenarios, including diet. The plasticity of these techniques allows their inclusion in human biomonitoring studies, adding important information with the ultimate aim of disease prevention, in particular cancer, and so it is important that they be included as genotoxicity assays in molecular epidemiology.

An Adaptive Approach for Defending against DDoS Attacks

Directory of Open Access Journals (Sweden)

Muhai Li

2010-01-01

Full Text Available In various network attacks, the Distributed Denial-of-Service (DDoS attack is a severe threat. In order to deal with this kind of attack in time, it is necessary to establish a special type of defense system to change strategy dynamically against attacks. In this paper, we introduce an adaptive approach, which is used for defending against DDoS attacks, based on normal traffic analysis. The approach can check DDoS attacks and adaptively adjust its configurations according to the network condition and attack severity. In order to insure the common users to visit the victim server that is being attacked, we provide a nonlinear traffic control formula for the system. Our simulation test indicates that the nonlinear control approach can prevent the malicious attack packets effectively while making legitimate traffic flows arrive at the victim.

Sensitivity of Bidens laevis L. to mutagenic compounds. Use of chromosomal aberrations as biomarkers of genotoxicity

Energy Technology Data Exchange (ETDEWEB)

Perez, D.J. [Laboratorio de Genetica, Estacion Experimental Agropecuaria Balcarce (INTA), Facultad de Ciencias Agrarias, UNMdP, CC 276, 7620 Balcarce (Argentina); Laboratorio de Ecotoxicologia, Departamento de Ciencias Marinas, Facultad de Ciencias Exactas y Naturales, UNMdP, Funes 3350, 7600 Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Rivadavia 1917, 1033 Buenos Aires (Argentina); Lukaszewicz, G. [Laboratorio de Ecotoxicologia, Departamento de Ciencias Marinas, Facultad de Ciencias Exactas y Naturales, UNMdP, Funes 3350, 7600 Mar del Plata (Argentina); Menone, M.L., E-mail: lujanm@mdp.edu.a [Laboratorio de Ecotoxicologia, Departamento de Ciencias Marinas, Facultad de Ciencias Exactas y Naturales, UNMdP, Funes 3350, 7600 Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Rivadavia 1917, 1033 Buenos Aires (Argentina); Camadro, E.L. [Laboratorio de Genetica, Estacion Experimental Agropecuaria Balcarce (INTA), Facultad de Ciencias Agrarias, UNMdP, CC 276, 7620 Balcarce (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Rivadavia 1917, 1033 Buenos Aires (Argentina)

2011-01-15

The wetland macrophyte Bidens laevis possesses suitable cytological characteristics for genotoxicity testing. To test its sensitivity as compared to terrestrial plants species currently in use in standardized assays, Methyl Methanesulfonate (MMS), N-ethyl-N-nitrosourea (ENU) and Maleic Hydrazide (HM) were used. On the other hand, the insecticide Endosulfan (ES) - an environmentally relevant contaminant - was assayed in seeds and two-month old plants. Mitotic Index (MI), frequency of Chromosome Aberrations in Anaphase-Telophase (CAAT) and frequency of Abnormal Metaphases (AM) were analyzed. MH, MMS and ENU caused a significant decrease of the MI. MMS was aneugenic whereas MH and ENU were both aneugenic and clastogenic. ES caused a significant concentration-dependent increase of total- and aneugenic-CAAT in roots and a significant high frequency of AM at high concentrations. Because of its sensitivity to mutagenic substances, B. laevis can be regarded as a reliable and convenient species for genotoxicity assays especially if aquatic contaminants are evaluated. - The wetland macrophyte Bidens laevis is sensitive to genotoxic compounds similarly to terrestrial standardized species.

Sensitivity of Bidens laevis L. to mutagenic compounds. Use of chromosomal aberrations as biomarkers of genotoxicity

International Nuclear Information System (INIS)

Perez, D.J.; Lukaszewicz, G.; Menone, M.L.; Camadro, E.L.

2011-01-01

The wetland macrophyte Bidens laevis possesses suitable cytological characteristics for genotoxicity testing. To test its sensitivity as compared to terrestrial plants species currently in use in standardized assays, Methyl Methanesulfonate (MMS), N-ethyl-N-nitrosourea (ENU) and Maleic Hydrazide (HM) were used. On the other hand, the insecticide Endosulfan (ES) - an environmentally relevant contaminant - was assayed in seeds and two-month old plants. Mitotic Index (MI), frequency of Chromosome Aberrations in Anaphase-Telophase (CAAT) and frequency of Abnormal Metaphases (AM) were analyzed. MH, MMS and ENU caused a significant decrease of the MI. MMS was aneugenic whereas MH and ENU were both aneugenic and clastogenic. ES caused a significant concentration-dependent increase of total- and aneugenic-CAAT in roots and a significant high frequency of AM at high concentrations. Because of its sensitivity to mutagenic substances, B. laevis can be regarded as a reliable and convenient species for genotoxicity assays especially if aquatic contaminants are evaluated. - The wetland macrophyte Bidens laevis is sensitive to genotoxic compounds similarly to terrestrial standardized species.

Perceptual load affects exogenous spatial orienting while working memory load does not.

Science.gov (United States)

Santangelo, Valerio; Finoia, Paola; Raffone, Antonino; Belardinelli, Marta Olivetti; Spence, Charles

2008-01-01

We examined whether or not increasing visual perceptual load or visual working memory (WM) load would affect the exogenous orienting of visuo-spatial attention, in order to assess whether or not exogenous orienting is genuinely automatic. In Experiment 1, we manipulated visual perceptual load by means of a central morphing shape that in some trials morphed into a particular target shape (a rectangle) that participants had to detect. In Experiment 2, the possibility that the presentation of any changing stimulus at fixation would eliminate exogenous orienting was ruled out, by presenting two alternating letters at fixation. In Experiment 3, we manipulated visual WM load by means of arrays consisting of three (low-load) or five (high-load) randomly located coloured squares. The participants had to remember these items in order to judge whether a cued square had been presented in the same or different colour at the end of each trial. In all the experiments, exogenous visuo-spatial attentional orienting was measured by means of an orthogonal spatial cuing task, in which the participants had to discriminate the elevation (up vs. down) of a visual target previously cued by a spatially nonpredictive visual cue. The results showed that increasing the perceptual load of the task eliminated the exogenous orienting of visuo-spatial attention. By contrast, increasing the WM load had no effect on spatial orienting. These results are discussed in terms of the light that they shed on claims regarding the automaticity of visuo-spatial exogenous orienting.

Countermeasures for unintentional and intentional video watermarking attacks

Science.gov (United States)

Deguillaume, Frederic; Csurka, Gabriela; Pun, Thierry

2000-05-01

These last years, the rapidly growing digital multimedia market has revealed an urgent need for effective copyright protection mechanisms. Therefore, digital audio, image and video watermarking has recently become a very active area of research, as a solution to this problem. Many important issues have been pointed out, one of them being the robustness to non-intentional and intentional attacks. This paper studies some attacks and proposes countermeasures applied to videos. General attacks are lossy copying/transcoding such as MPEG compression and digital/analog (D/A) conversion, changes of frame-rate, changes of display format, and geometrical distortions. More specific attacks are sequence edition, and statistical attacks such as averaging or collusion. Averaging attack consists of averaging locally consecutive frames to cancel the watermark. This attack works well for schemes which embed random independent marks into frames. In the collusion attack the watermark is estimated from single frames (based on image denoising), and averaged over different scenes for better accuracy. The estimated watermark is then subtracted from each frame. Collusion requires that the same mark is embedded into all frames. The proposed countermeasures first ensures robustness to general attacks by spread spectrum encoding in the frequency domain and by the use of an additional template. Secondly, a Bayesian criterion, evaluating the probability of a correctly decoded watermark, is used for rejection of outliers, and to implement an algorithm against statistical attacks. The idea is to embed randomly chosen marks among a finite set of marks, into subsequences of videos which are long enough to resist averaging attacks, but short enough to avoid collusion attacks. The Bayesian criterion is needed to select the correct mark at the decoding step. Finally, the paper presents experimental results showing the robustness of the proposed method.

Link-layer Jamming Attacks on S-MAC

NARCIS (Netherlands)

Law, Y.W.; Hartel, Pieter H.; den Hartog, Jeremy; Havinga, Paul J.M.

2004-01-01

We argue that among denial-of-service (DoS) attacks, link-layer jamming is a more attractive option to attackers than radio jamming is. By exploiting the semantics of the link-layer protocol (aka MAC protocol), an attacker can achieve better efficiency than blindly jamming the radio signals alone.

Link-layer jamming attacks on S-MAC

NARCIS (Netherlands)

Law, Y.W.; Hartel, Pieter H.; den Hartog, Jeremy; Havinga, Paul J.M.

We argue that among denial-of-service (DoS) attacks, link-layer jamming is a more attractive option to attackers than radio jamming is. By exploiting the semantics of the link-layer protocol (aka MAC protocol), an attacker can achieve better efficiency than blindly jamming the radio signals alone.

An Exogenous Surfactant-Producing Bacillus subtilis Facilitates Indigenous Microbial Enhanced Oil Recovery.

Science.gov (United States)

Gao, Peike; Li, Guoqiang; Li, Yanshu; Li, Yan; Tian, Huimei; Wang, Yansen; Zhou, Jiefang; Ma, Ting

2016-01-01

This study used an exogenous lipopeptide-producing Bacillus subtilis to strengthen the indigenous microbial enhanced oil recovery (IMEOR) process in a water-flooded reservoir in the laboratory. The microbial processes and driving mechanisms were investigated in terms of the changes in oil properties and the interplay between the exogenous B. subtilis and indigenous microbial populations. The exogenous B. subtilis is a lipopeptide producer, with a short growth cycle and no oil-degrading ability. The B. subtilis facilitates the IMEOR process through improving oil emulsification and accelerating microbial growth with oil as the carbon source. Microbial community studies using quantitative PCR and high-throughput sequencing revealed that the exogenous B. subtilis could live together with reservoir microbial populations, and did not exert an observable inhibitory effect on the indigenous microbial populations during nutrient stimulation. Core-flooding tests showed that the combined exogenous and indigenous microbial flooding increased oil displacement efficiency by 16.71%, compared with 7.59% in the control where only nutrients were added, demonstrating the application potential in enhanced oil recovery in water-flooded reservoirs, in particular, for reservoirs where IMEOR treatment cannot effectively improve oil recovery.

A computer network attack taxonomy and ontology

CSIR Research Space (South Africa)

Van Heerden, RP

2012-01-01

Full Text Available of the attack that occur after the attack goal has been achieved, and occurs because the attacker loses control of some systems. For example, after the launch of a DDOS (Distributed Denial of Service) attack, zombie computers may still connect to the target...-scrap- value-of-a-hacked-pc-revisited/ . Lancor, L., & Workman, R. (2007). Using Google Hacking to Enhance Defense Strategies. ACM SIGCSE Bulletin, 39 (1), 491-495. Lau, F., Rubin, S. H., Smith, M. H., & Trajkovic, L. (2000). Distributed Denial of Service...

Critical review of the current and future challenges associated with advanced in vitro systems towards the study of nanoparticle (secondary) genotoxicity.

Science.gov (United States)

Evans, Stephen J; Clift, Martin J D; Singh, Neenu; de Oliveira Mallia, Jefferson; Burgum, Michael; Wills, John W; Wilkinson, Thomas S; Jenkins, Gareth J S; Doak, Shareen H

2017-01-01

With the need to understand the potential biological impact of the plethora of nanoparticles (NPs) being manufactured for a wide range of potential human applications, due to their inevitable human exposure, research activities in the field of NP toxicology has grown exponentially over the last decade. Whilst such increased research efforts have elucidated an increasingly significant knowledge base pertaining to the potential human health hazard posed by NPs, understanding regarding the possibility for NPs to elicit genotoxicity is limited. In vivo models are unable to adequately discriminate between the specific modes of action associated with the onset of genotoxicity. Additionally, in line with the recent European directives, there is an inherent need to move away from invasive animal testing strategies. Thus, in vitro systems are an important tool for expanding our mechanistic insight into NP genotoxicity. Yet uncertainty remains concerning their validity and specificity for this purpose due to the unique challenges presented when correlating NP behaviour in vitro and in vivo This review therefore highlights the current state of the art in advanced in vitro systems and their specific advantages and disadvantages from a NP genotoxicity testing perspective. Key indicators will be given related to how these systems might be used or improved to enhance understanding of NP genotoxicity. © The Author 2016. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society.

Evaluation of genotoxicity after application of Listerine(R) on human lymphocytes by micronucleus and single cell gel electrophoresis assays.

Science.gov (United States)

Türkez, Hasan; Togar, Basak; Arabaci, Taner

2012-04-01

Listerine (LN) is one of the most commonly used mouth rinses worldwide although very limited information is available concerning its genotoxicity. In another view, the biological safety profile of oral care products is frequently assumed on the basis of simplistic test models. Therefore, the present study was undertaken to investigate the in vitro genotoxic potential of LN using micronucleus and single cell gel electrophoresis tests as genetic endpoints. Different concentrations of LN (0-100% of ml/culture, v/v) were applied to whole human blood cultures (n = 5). The result of the present study showed that there were no statistically significant differences (p > 0.05) between the control group and the groups treated with LN alone in both analysed endpoints. In conclusion, our result first demonstrated the absence of genotoxicity of LN on human lymphocytes.

Using synergistic exogenous phytohormones to enhance somatic ...

African Journals Online (AJOL)

Southern Forests: a Journal of Forest Science ... Eucalyptus spp. has been limited to germinated seeds, flowers, lignotubers or zygotic embryos. ... explants could be enhanced through pairing of synergistic exogenous plant growth regulators, ...

The genotoxic effect of oxcarbazepine on mice blood lymphocytes.

Science.gov (United States)

Akbar, Huma; Khan, Ajmal; Mohammadzai, Imdadullah; Khisroon, Muhammad; Begum, Ilham

2018-04-01

This study was conducted to assess the amount of DNA damage caused by Oxcarbazepine (OXC) through single cell gel electrophoresis (SCGE) technique/comet assay. OXC derived from dibenzazepine series is an effective second generation antiepileptic drug (AED) for both children and adults. Side effects like genotoxic effects of AEDs are of prime importance resulting from toxic metabolites, free radicals and reactive oxygen species (ROS). Forty Eight adult male Bagg's albino mice (BALB/c) were randomly classified into eight groups, each comprising of six animals. Two of these groups were control and six were tested groups. Control groups were injected with 1% tween 80 while tested groups were injected with 10, 20, and 40 mg/kg-day OXC for seven days (acute therapy) and 28 days (subchronic therapy) in peritoneal cavity. Blood samples were collected by cardiac puncture and subjected to comet assay for the analysis of DNA damage. Per sample 100 cells were scored and classified according to comet tail length. The results showed that OXC in acute and long term therapies had significantly higher (p < 0.05) genotoxicity in treated groups as compared to control groups. Our study suggests that OXC may cause significant DNA damage in both acute as well as in subchronic therapies.

In vivo genotoxicity assessment of acrylamide and glycidyl methacrylate.

Science.gov (United States)

Dobrovolsky, Vasily N; Pacheco-Martinez, M Monserrat; McDaniel, L Patrice; Pearce, Mason G; Ding, Wei

2016-01-01

Acrylamide (ACR) and glycidyl methacrylate (GMA) are structurally related compounds used for making polymers with various properties. Both chemicals can be present in food either as a byproduct of processing or a constituent of packaging. We performed a comprehensive evaluation of ACR and GMA genotoxicity in Fisher 344 rats using repeated gavage administrations. Clastogenicity was measured by scoring micronucleated (MN) erythrocytes from peripheral blood, DNA damage in liver, bone marrow and kidneys was measured using the Comet assay, and gene mutation was measured using the red blood cell (RBC) and reticulocyte Pig-a assay. A limited histopathology evaluation was performed in order to determine levels of cytotoxicity. Doses of up to 20 mg/kg/day of ACR and up to 250 mg/kg/day of GMA were used. ACR treatment resulted in DNA damage in the liver, but not in the bone marrow. While ACR was not a clastogen, it was a weak (equivocal) mutagen in the cells of bone marrow. GMA caused DNA damage in the cells of bone marrow, liver and kidney, and induced MN reticulocytes and Pig-a mutant RBCs in a dose-dependent manner. Collectively, our data suggest that both compounds are in vivo genotoxins, but the genotoxicity of ACR is tissue specific. Published by Elsevier Ltd.

Unified communications forensics anatomy of common UC attacks

CERN Document Server

Grant, Nicholas Mr

2013-01-01

Unified Communications Forensics: Anatomy of Common UC Attacks is the first book to explain the issues and vulnerabilities and demonstrate the attacks, forensic artifacts, and countermeasures required to establish a secure (UC) environment. This book is written by leading UC experts Nicholas Grant and Joseph W. Shaw II and provides material never before found on the market, including: analysis of forensic artifacts in common UC attacks an in-depth look at established UC technologies and attack exploits hands-on understanding of UC attack vectors and associated countermeasures

INVESTMENT EFFECTS OF ENDOGENOUS AND EXOGENOUS DEPRECIATION: IMPROVED PASTURES IN URUGUAY

OpenAIRE

Ekboir, Javier M.; Jarvis, Lovell S.; Rey, Carlos

1998-01-01

The depreciation rate for capital assets may have endogenous and exogenous components. Change in the exogenous component depends on technological change and/or environmental factors, shifts the production function, and independently affects profitability and investment. Change in the endogenous component does not. These hypotheses are tested using data on Uruguayan grass-legume pastures.

Correlation between the genotoxicity endpoints measured by two different genotoxicity assays: comet assay and CBMN assay

Directory of Open Access Journals (Sweden)

Carina Ladeira

2015-06-01

The results concerning of positive findings by micronuclei and non significant ones by comet assay, are corroborated by Deng et al. (2005 study performed in workers occupationally exposed to methotrexate, also a cytostatic drug. According to Cavallo et al. (2009, the comet assay seems to be more suitable for the prompt evaluation of the genotoxic effects, for instance, of polycyclic aromatic hydrocarbons mixtures containing volatile substances, whereas the micronucleus test seems more appropriate to evaluate the effects of exposure to antineoplastic agents. However, there are studies that observed an increase in both the comet assay and the micronucleus test in nurses handling antineoplastic drugs, although statistical significance was only seen in the comet assay, quite the opposite of our results (Maluf & Erdtmann, 2000; Laffon et al. 2005.

In vivo genotoxic effects of dietary heme iron on rat colon mucosa and ex vivo effects on colon cells monitored by an optimized alkaline comet assay.

Directory of Open Access Journals (Sweden)

Océane, C Martin

2015-04-01

In conclusion, our results offer a suitable protocol to evaluate genotoxicity on in vivo cryopreserved colon mucosa and on in vitro murine colonic cells, with a middle throughput capacity. This protocol confirms the increase of genotoxicity in rat colon mucosa after an heme-iron diet. Moreover, this protocol enables the demonstration that aldehydes from heme-induced lipoperoxidation are responsible for this increase of genotoxicity.

Attacks and countermeasures on AES and ECC

DEFF Research Database (Denmark)

Tange, Henrik; Andersen, Birger

2013-01-01

AES (Advanced Encryption Standard) is widely used in LTE and Wi-Fi communication systems. AES has recently been exposed to new attacks which have questioned the overall security of AES. The newest attack is a so called biclique attack, which is using the fact that the content of the state array...

Genotoxic potential evaluation of a cosmetic insoluble substance by the micronuclei assay.

Science.gov (United States)

Dayan, N; Shah, V; Minko, T

2011-01-01

An optical brightener (OB) powder (INCI: sodium silicoaluminate (and) glycidoxypropyl trimethyloxysilane/PEI-250 cross fluorescent brightener 230 salt (and) polyvinylalcohol crosspolymer) that is used in cosmetic facial products was tested for its genotoxic potential using the micronuclei test (MNT). It is a solid dry powder with an average size of 5 microns that is insoluble but dispersible in water. This study describes the exposure of cell culture to positive controls with and without enzymatic activation and to the test compound in different concentrations. We evaluated three end points: microscopic observation and quantification of micronuclei formation, and cell viability and proliferation. Both positive controls induced significant changes that were observed under the microscope and quantified. Based on its chemical nature, it was not anticipated that the test substance will degrade under the conditions of the experiments. However, the test is required to make sure that when solublized, impurities that may be present, even at trace levels, will not induce a genotoxic effect. The test compound did not promote micronuclei formation or change the viability or proliferation rate of cells. During this study we faced challenges such as solubilization and correlating viability data to genotoxicity data. These are described in the body of the paper. We believe that with the emergence of the 7(th) European amendment that bans animal testing, sharing these data and the study protocol serves as a key in building the understanding of the utilization of in vitro studies in the safety assessment of cosmetic ingredients.

Classifying network attack scenarios using an ontology

CSIR Research Space (South Africa)

Van Heerden, RP

2012-03-01

Full Text Available ) or to the target?s reputation. The Residue sub-phase refers to damage or artefacts of the attack that occur after the attack goal has been achieved, and occurs because the attacker loses control of some systems. For example after the launch of a DDOS..., A. (1995). Hacking theft of $10 million from citibank revealed. Retrieved 10/10, 2011, from http://articles.latimes.com/1995-08-19/business/fi-36656_1_citibank-system Hurley, E. (2004). SCO site succumbs to DDoS attack. Retrieved 10/10, 2011, from...

Modelling Social-Technical Attacks with Timed Automata

DEFF Research Database (Denmark)

David, Nicolas; David, Alexandre; Hansen, Rene Rydhof

2015-01-01

. In this paper we develop an approach towards modelling socio-technical systems in general and socio-technical attacks in particular, using timed automata and illustrate its application by a complex case study. Thanks to automated model checking and automata theory, we can automatically generate possible attacks...... in our model and perform analysis and simulation of both model and attack, revealing details about the specific interaction between attacker and victim. Using timed automata also allows for intuitive modelling of systems, in which quantities like time and cost can be easily added and analysed....

Quantitative Verification and Synthesis of Attack-Defence Scenarios

DEFF Research Database (Denmark)

Aslanyan, Zaruhi; Nielson, Flemming; Parker, David

2016-01-01

analysis of quantitative properties of complex attack-defence scenarios, using an extension of attack-defence trees which models temporal ordering of actions and allows explicit dependencies in the strategies adopted by attackers and defenders. We adopt a game-theoretic approach, translating attack...... which guarantee or optimise some quantitative property, such as the probability of a successful attack, the expected cost incurred, or some multi-objective trade-off between the two. We implement our approach, building upon the PRISM-games model checker, and apply it to a case study of an RFID goods...

Differential effects of exogenous and endogenous attention on second-order texture contrast sensitivity

Science.gov (United States)

Barbot, Antoine; Landy, Michael S.; Carrasco, Marisa

2012-01-01

The visual system can use a rich variety of contours to segment visual scenes into distinct perceptually coherent regions. However, successfully segmenting an image is a computationally expensive process. Previously we have shown that exogenous attention—the more automatic, stimulus-driven component of spatial attention—helps extract contours by enhancing contrast sensitivity for second-order, texture-defined patterns at the attended location, while reducing sensitivity at unattended locations, relative to a neutral condition. Interestingly, the effects of exogenous attention depended on the second-order spatial frequency of the stimulus. At parafoveal locations, attention enhanced second-order contrast sensitivity to relatively high, but not to low second-order spatial frequencies. In the present study we investigated whether endogenous attention—the more voluntary, conceptually-driven component of spatial attention—affects second-order contrast sensitivity, and if so, whether its effects are similar to those of exogenous attention. To that end, we compared the effects of exogenous and endogenous attention on the sensitivity to second-order, orientation-defined, texture patterns of either high or low second-order spatial frequencies. The results show that, like exogenous attention, endogenous attention enhances second-order contrast sensitivity at the attended location and reduces it at unattended locations. However, whereas the effects of exogenous attention are a function of the second-order spatial frequency content, endogenous attention affected second-order contrast sensitivity independent of the second-order spatial frequency content. This finding supports the notion that both exogenous and endogenous attention can affect second-order contrast sensitivity, but that endogenous attention is more flexible, benefitting performance under different conditions. PMID:22895879

Differential effects of exogenous and endogenous attention on second-order texture contrast sensitivity.

Science.gov (United States)

Barbot, Antoine; Landy, Michael S; Carrasco, Marisa

2012-08-15

The visual system can use a rich variety of contours to segment visual scenes into distinct perceptually coherent regions. However, successfully segmenting an image is a computationally expensive process. Previously we have shown that exogenous attention--the more automatic, stimulus-driven component of spatial attention--helps extract contours by enhancing contrast sensitivity for second-order, texture-defined patterns at the attended location, while reducing sensitivity at unattended locations, relative to a neutral condition. Interestingly, the effects of exogenous attention depended on the second-order spatial frequency of the stimulus. At parafoveal locations, attention enhanced second-order contrast sensitivity to relatively high, but not to low second-order spatial frequencies. In the present study we investigated whether endogenous attention-the more voluntary, conceptually-driven component of spatial attention--affects second-order contrast sensitivity, and if so, whether its effects are similar to those of exogenous attention. To that end, we compared the effects of exogenous and endogenous attention on the sensitivity to second-order, orientation-defined, texture patterns of either high or low second-order spatial frequencies. The results show that, like exogenous attention, endogenous attention enhances second-order contrast sensitivity at the attended location and reduces it at unattended locations. However, whereas the effects of exogenous attention are a function of the second-order spatial frequency content, endogenous attention affected second-order contrast sensitivity independent of the second-order spatial frequency content. This finding supports the notion that both exogenous and endogenous attention can affect second-order contrast sensitivity, but that endogenous attention is more flexible, benefitting performance under different conditions.

Exogenous and endogenous landforms in the Mediterranean

Science.gov (United States)

Acar, Julia

2017-04-01

11th graders have already learned about endogenous forces and now we are having a closer look at the exogenous forces which act on the Earth's surface. The Po River-system, for example, is responsible for the formation of the alpine region. Students are asked to find out how this works with the help of the rock-cycle scheme, several suitable maps and information on weathering and the texture of rocks, erosion, etc. We will form groups that will look at different types of rock formations (including an example in the Mediterranean region each). Depending on the number of lessons available we will add the exogenous effect of flowing water and ice (glacial over forming) to the topic. At the end every group will present their findings explaining the scientific context by using topographic examples.

Situational awareness of a coordinated cyber attack

Science.gov (United States)

Sudit, Moises; Stotz, Adam; Holender, Michael

2005-03-01

As technology continues to advance, services and capabilities become computerized, and an ever increasing amount of business is conducted electronically the threat of cyber attacks gets compounded by the complexity of such attacks and the criticality of the information which must be secured. A new age of virtual warfare has dawned in which seconds can differentiate between the protection of vital information and/or services and a malicious attacker attaining their goal. In this paper we present a novel approach in the real-time detection of multistage coordinated cyber attacks and the promising initial testing results we have obtained. We introduce INFERD (INformation Fusion Engine for Real-time Decision-making), an adaptable information fusion engine which performs fusion at levels zero, one, and two to provide real-time situational assessment and its application to the cyber domain in the ECCARS (Event Correlation for Cyber Attack Recognition System) system. The advantages to our approach are fourfold: (1) The complexity of the attacks which we consider, (2) the level of abstraction in which the analyst interacts with the attack scenarios, (3) the speed at which the information fusion is presented and performed, and (4) our disregard for ad-hoc rules or a priori parameters.

Endogenous versus exogenous growth factor regulation of articular chondrocytes.

Science.gov (United States)

Shi, Shuiliang; Chan, Albert G; Mercer, Scott; Eckert, George J; Trippel, Stephen B

2014-01-01

Anabolic growth factors that regulate the function of articular chondrocytes are candidates for articular cartilage repair. Such factors may be delivered by pharmacotherapy in the form of exogenous proteins, or by gene therapy as endogenous proteins. It is unknown whether delivery method influences growth factor effectiveness in regulating articular chondrocyte reparative functions. We treated adult bovine articular chondrocytes with exogenous recombinant insulin-like growth factor-I (IGF-I) and transforming growth factor-beta1 (TGF-β1), or with the genes encoding these growth factors for endogenous production. Treatment effects were measured as change in chondrocyte DNA content, glycosaminoglycan production, and aggrecan gene expression. We found that IGF-I stimulated chondrocyte biosynthesis similarly when delivered by either exogenous or endogenous means. In contrast, exogenous TGF-β1 stimulated these reparative functions, while endogenous TGF-β1 had little effect. Endogenous TGF-β1 became more bioactive following activation of the transgene protein product. These data indicate that effective mechanisms of growth factor delivery for articular cartilage repair may differ for different growth factors. In the case of IGF-I, gene therapy or protein therapy appear to be viable options. In contrast, TGF-β1 gene therapy may be constrained by a limited ability of chondrocytes to convert latent complexes to an active form. Published 2013 by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. This article is a U.S. Government work and is in the public domain in the USA.

Exogenous lipoid pneumonia – a case report of a fire-eater

International Nuclear Information System (INIS)

Pielaszkiewicz-Wydra, Magdalena; Homola-Piekarska, Bożena; Szcześniak, Ewa; Ciołek-Zdun, Monika; Fall, Andrzej

2012-01-01

Exogenous lipoid pneumonia is an uncommon condition caused by inhalation or aspiration of a fatty substance. It usually presents as chronic respiratory illness mimicking interstitial lung diseases. Acute exogenous lipoid pneumonia is uncommon and typically is caused by an episode of aspiration of a large quantity of a petroleum-based product. Radiological findings vary and may imitate many other diseases. We present a rare case of acute exogenous lipoid pneumonia in a fire-eater who aspirated liquid paraffin during his flame-blowing show (fire-eater’s lung). He was admitted to the hospital with productive cough, fever, hemoptysis, chest pain and dyspnea. Diagnosis was made on the basis of history of exposure to fatty substance, characteristic findings in CT examination and presence of lipid-laden macrophages in bronchoalveolar lavage fluid. Acute exogenous lipoid pneumonia is a very rare disease that typically occurs in fire-eaters and is called a fire-eater’s lung. The diagnosis is made on the basis of typical history and radiological, as well as histopathological findings

GENOTOXICITY OF BIOREMEDIATED SOILS FROM THE REILLY TARSITE, ST. LOUIS PARK, MINNESOTA

Science.gov (United States)

An in vitro approach was used to measure the genotoxicity of creosote-contaminated soil before and after four bioremediation processes. The soil was taken from the Reilly Tar site, a closed Superfund site in Saint Louis Park, Minnesota. The creosote soil was bioremediated in bios...

Anti-discrimination Analysis Using Privacy Attack Strategies

KAUST Repository

Ruggieri, Salvatore

2014-09-15

Social discrimination discovery from data is an important task to identify illegal and unethical discriminatory patterns towards protected-by-law groups, e.g., ethnic minorities. We deploy privacy attack strategies as tools for discrimination discovery under hard assumptions which have rarely tackled in the literature: indirect discrimination discovery, privacy-aware discrimination discovery, and discrimination data recovery. The intuition comes from the intriguing parallel between the role of the anti-discrimination authority in the three scenarios above and the role of an attacker in private data publishing. We design strategies and algorithms inspired/based on Frèchet bounds attacks, attribute inference attacks, and minimality attacks to the purpose of unveiling hidden discriminatory practices. Experimental results show that they can be effective tools in the hands of anti-discrimination authorities.

Genotoxic and Antigenotoxic Potential of Momordica charantia Linn (Cucurbitaceae) in the Wing Spot Test of Drosophila melanogaster.

Science.gov (United States)

Guterres, Zaira Rosa; Zanetti, Thalita Alves; Sennes-Lopes, Tiago Felipe; da Silva, Ana Francisca Gomes

2015-10-01

Momordica charantia, popularly known as bitter melon, is a plant widely used in ethnobotanical medicine. It has antibacterial, antifungal, anthelmintic, antidiabetic, antiviral, and antimalarial activities, among others. The goal of this study was to evaluate the genotoxic and/or antigenotoxic activity of the aqueous extracts obtained from the aerial parts and fruit of this plant by means of the Drosophila melanogaster wing spot test. Third-stage larvae that obtained standard (ST) cross and high bioactivation (HB) cross were treated with aqueous extracts of the aerial parts (IQA) and fruit (IQF) of M. charantia, following two protocols (genotoxicity and antigenotoxicity). The aqueous extracts are not genotoxic in lower concentrations. The frequencies of mutant spots observed in the descendants of the ST and HB crosses treated with doxorubicin (DXR) alone were 8.65 and 9.25, respectively, whereas in those cotreated with IQA and DXR, the frequencies ranged from 15.90 to 29 in the ST cross and from 15.05 to 24.78 in the HB cross. In cotreatment with IQF, the frequencies ranged from 30.10 to 30.65 in the ST cross and from 13.60 to 14.50 in the HB cross, whereas the frequencies obtained with DXR were 32.50 in the ST cross and 26.00 in the HB cross. In conclusion, the IQA has a synergistic effect, enhancing the genotoxicity of DXR in the ST cross and the HB cross, whereas the IQF has antigenotoxic effects in the HB cross.

Trajectory Control of Scale-Free Dynamical Networks with Exogenous Disturbances

International Nuclear Information System (INIS)

Yang Hongyong; Zhang Shun; Zong Guangdeng

2011-01-01

In this paper, the trajectory control of multi-agent dynamical systems with exogenous disturbances is studied. Suppose multiple agents composing of a scale-free network topology, the performance of rejecting disturbances for the low degree node and high degree node is analyzed. Firstly, the consensus of multi-agent systems without disturbances is studied by designing a pinning control strategy on a part of agents, where this pinning control can bring multiple agents' states to an expected consensus track. Then, the influence of the disturbances is considered by developing disturbance observers, and disturbance observers based control (DOBC) are developed for disturbances generated by an exogenous system to estimate the disturbances. Asymptotical consensus of the multi-agent systems with disturbances under the composite controller can be achieved for scale-free network topology. Finally, by analyzing examples of multi-agent systems with scale-free network topology and exogenous disturbances, the verities of the results are proved. Under the DOBC with the designed parameters, the trajectory convergence of multi-agent systems is researched by pinning two class of the nodes. We have found that it has more stronger robustness to exogenous disturbances for the high degree node pinned than that of the low degree node pinned. (interdisciplinary physics and related areas of science and technology)

Exogenous mRNA encoding tetanus or botulinum neurotoxins expressed in Aplysia neurons

NARCIS (Netherlands)

Mochida, Sumiko; Poulain, Bernard; Eisel, Ulrich; Binz, Thomas; Kurazono, Hisao; Niemann, Heiner; Tauc, Ladislav; Bullock, Theodore H.

1990-01-01

Injection of exogenous mRNA purified from various tissue preparations into cellular translation systems such as Xenopus oocytes has allowed expression of complex proteins (e.g., receptors for neurotransmitters). No evidence for expression of injected exogenous mRNA, however, has been reported in

Cyberprints: Identifying Cyber Attackers by Feature Analysis

Science.gov (United States)

Blakely, Benjamin A.

2012-01-01

The problem of attributing cyber attacks is one of increasing importance. Without a solid method of demonstrating the origin of a cyber attack, any attempts to deter would-be cyber attackers are wasted. Existing methods of attribution make unfounded assumptions about the environment in which they will operate: omniscience (the ability to gather,…

Simulation of Attacks for Security in Wireless Sensor Network.

Science.gov (United States)

Diaz, Alvaro; Sanchez, Pablo

2016-11-18

The increasing complexity and low-power constraints of current Wireless Sensor Networks (WSN) require efficient methodologies for network simulation and embedded software performance analysis of nodes. In addition, security is also a very important feature that has to be addressed in most WSNs, since they may work with sensitive data and operate in hostile unattended environments. In this paper, a methodology for security analysis of Wireless Sensor Networks is presented. The methodology allows designing attack-aware embedded software/firmware or attack countermeasures to provide security in WSNs. The proposed methodology includes attacker modeling and attack simulation with performance analysis (node's software execution time and power consumption estimation). After an analysis of different WSN attack types, an attacker model is proposed. This model defines three different types of attackers that can emulate most WSN attacks. In addition, this paper presents a virtual platform that is able to model the node hardware, embedded software and basic wireless channel features. This virtual simulation analyzes the embedded software behavior and node power consumption while it takes into account the network deployment and topology. Additionally, this simulator integrates the previously mentioned attacker model. Thus, the impact of attacks on power consumption and software behavior/execution-time can be analyzed. This provides developers with essential information about the effects that one or multiple attacks could have on the network, helping them to develop more secure WSN systems. This WSN attack simulator is an essential element of the attack-aware embedded software development methodology that is also introduced in this work.

Simulation of Attacks for Security in Wireless Sensor Network

Science.gov (United States)

Diaz, Alvaro; Sanchez, Pablo

2016-01-01

The increasing complexity and low-power constraints of current Wireless Sensor Networks (WSN) require efficient methodologies for network simulation and embedded software performance analysis of nodes. In addition, security is also a very important feature that has to be addressed in most WSNs, since they may work with sensitive data and operate in hostile unattended environments. In this paper, a methodology for security analysis of Wireless Sensor Networks is presented. The methodology allows designing attack-aware embedded software/firmware or attack countermeasures to provide security in WSNs. The proposed methodology includes attacker modeling and attack simulation with performance analysis (node’s software execution time and power consumption estimation). After an analysis of different WSN attack types, an attacker model is proposed. This model defines three different types of attackers that can emulate most WSN attacks. In addition, this paper presents a virtual platform that is able to model the node hardware, embedded software and basic wireless channel features. This virtual simulation analyzes the embedded software behavior and node power consumption while it takes into account the network deployment and topology. Additionally, this simulator integrates the previously mentioned attacker model. Thus, the impact of attacks on power consumption and software behavior/execution-time can be analyzed. This provides developers with essential information about the effects that one or multiple attacks could have on the network, helping them to develop more secure WSN systems. This WSN attack simulator is an essential element of the attack-aware embedded software development methodology that is also introduced in this work. PMID:27869710