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Collaborative study on fifteen compounds in the rat-liver Comet assay integrated into 2- and 4-week repeat-dose studies.

A collaborative trial was conducted to evaluate the possibility of integrating the rat-liver Comet assay into repeat-dose toxicity studies. Fourteen laboratories from Europe, Japan and the USA tested fifteen chemicals. Two chemicals had been previously shown to induce micronuclei in an acute protocol, but were found negative in a 4-week Micronucleus (MN) Assay (benzo[a]pyrene and 1,2-dimethylhydrazine; Hamada et al., 2001); four genotoxic rat-liver carcinogens that were negative in the MN assay in bone marrow or blood (2,6-dinitrotoluene, dimethylnitrosamine, 1,2-dibromomethane, and 2-amino-3-…

SIN-1-induced DNA damage in isolated human peripheral blood lymphocytes as assessed by single cell gel electrophoresis (comet assay).

Human lymphocytes were exposed to increasing concentrations of SIN-1, which generates superoxide and nitric oxide, and the formation of single-strand breaks (SSB) in individual cells was determined by the single-cell gel electrophoresis assay (comet assay). A dose- and time-dependent increase in SSB formation was observed rapidly after the addition of SIN-1 (0.1-15 mM). Exposure of the cells to SIN-1 (5 mM) in the presence of excess of superoxide dismutase (0.375 mM) increased the formation of SSB significantly, whereas 1000 U/ml catalase significantly decreased the quantity of SSB. The simult…

Caiman latirostris (broad-snouted caiman) as a sentinel organism for genotoxic monitoring: basal values determination of micronucleus and comet assay.

Caiman latirostris is one of the two crocodilian species that inhabit Argentina. In this country, as a consequence of agricultural frontiers … ion in C. latirostris. The aim of this study was to adapt two widely used genotoxic techniques, the comet assay and the micronucleus test, for their application in C. latirostris and to determine the baseline values in this species, in order to establish its suitability as a sentinel organism for future genotoxic monitoring of environmental pollutants. A tota …

Lack of genotoxicity induced by endogenous and synthetic female sex hormones in peripheral blood cells detected by alkaline comet assay.

The etiology of hormone-induced cancers has been considered to be a combination of genotoxic and epigenetic events. Currently, the Comet assay is widely used for detecting genotoxicity because it is relatively simple, sensitive, and capable of detecting various kinds of DNA damage. The present study evaluates the genotoxic potential of endogenous and synthetic sex hormones, as detected by the Comet assay. Blood cells were obtained from 12 nonsmoking and 12 smoking women with regular menstrual cycles and from 12 nonsmoking women taking low-dose oral contraceptives (OC). Peripheral blood samples…

Comparison of the transgenic rodent mutation assay, error corrected next generation duplex sequencing, and the alkaline comet assay to detect dose-related mutations following exposure to N-nitrosodiethylamine.

N-Nitrosodiethylamine (NDEA), a well-studied N-nitrosamine, was tested in rats to compare the dose-response relationship of three genotoxicity endpoints. Mutant / mutation frequencies were determined using the transgenic rodent (TGR) gene mutation assay and error corrected next generation sequencing (ecNGS) (i.e., duplex sequencing (DS)), and genetic damage was detected by the alkaline comet assay. Big Blue® (cII Locus) animals (n = 6 per dose group) were administered doses of 0.001, 0.01, 0.1, 1, 3 mg/kg/day NDEA by oral gavage. Samples were collected for cII mutation and DS analyses followin…

Comparison of the genotoxicity of propofol and desflurane using the comet assay in the lymphocytes of patients who underwent lumbar discectomy: A randomized trial.

OBJECTIVES: To compare the genotoxic effects of desflurane and propofol using comet assay in patients undergoing elective discectomy surgery. METHODS: This was a randomized controlled study. Patients who underwent elective lumbar discectomy under general anesthesia with propofol or desflurane were included in the study. Venous blood samples were obtained at 4 different time points: 5 minutes before anesthesia induction (T1), 2 hours after the start of anesthesia (T2), the first day after surgery (T3), and the fifth day following surgery (T4). Deoxyribonucleic acid damage in lymphocytes was as…

In Vivo Genotoxicity Evaluation of a Stilbene Extract Prior to Its Use as a Natural Additive: A Combination of the Micronucleus Test and the Comet Assay.

Genotoxic data of substances that could be used as food additives are required by the European Food Safety Authority. In this sense, the use … ination of micronucleus assay in bone marrow (OECD 474) and standard (OECD 489) and enzyme-modified comet assay was used to determine the genotoxicity on cells isolated from stomach, liver, and blood of exposed animals. The ST-99 revealed no in vivo genotoxicity. These results were corroborated by analytical studies that confirm the presence of stilbenes and …

Evaluation of DNA damage using the comet assay in children on long-term benzathine penicillin for secondary prophylaxis of rheumatic fever.

BACKGROUND: Benzathine penicillin is the most widely used antibiotic in the prophylaxis of children with rheumatic fever. The aim of the present study was to evaluate the DNA damage in children receiving one dose of 1.2 million units benzathine penicillin every 4 weeks over a long period to prevent recurrences of rheumatic fever. METHODS: Thirty-five children with confirmed rheumatic fever under benzathine penicillin prophylaxis were enrolled in the study and 35 healthy children with similar ages and socioeconomic backgrounds served as controls. To detect any DNA damage, the comet assay was p…

Effects of melatonin on N-nitroso-N-methylurea-induced carcinogenesis in rats and mutagenesis in vitro (Ames test and COMET assay).

The effect of melatonin, an indole hormone of the pineal gland, on the initiation of N-nitroso-N-methylurea (NMU)-induced carcinogenesis in … and TA 102 of Salmonella typhimurium) and the Single Cell Gel Electrophoresis assay (SCGE assay or COMET assay) performed on CHOK1 cells. Melatonin itself revealed no genotoxic effect in either of the tests. No protective action of melatonin (at doses of up to 2 micromol/plate) towards NMU was found in the Ames test. In contrast, in the SCGE assay a slight, …

Genotoxicity of the herbicide formulation Roundup (glyphosate) in broad-snouted caiman (Caiman latirostris) evidenced by the Comet assay and the Micronucleus test.

The genotoxicity of pesticides is an issue of worldwide concern. The present study was undertaken to evaluate the genotoxic potential of a widely used herbicide formulation, Roundup (glyphosate), in erythrocytes of broad-snouted caiman (Caiman latirostris) after in ovo exposure. Caiman embryos were exposed at early embryonic stage to different sub-lethal concentrations of Roundup (50, 100, 200, 300, 400, 500, 750, 1000, 1250 and 1750microg/egg). At time of hatching, blood samples were obtained from each animal and two short-term tests, the Comet assay and the Micronucleus (MN) test, were perfo…

Assessment of the genotoxicity of trichloroethylene and its metabolite, S-(1,2-dichlorovinyl)-L-cysteine (DCVC), in the comet assay in rat kidney.

Trichloroethylene (TCE) has been reported to give a small, but significant, increase in renal tumours in the rat. These tumours were always associated with nephrotoxicity which is most likely caused by the metabolism of TCE to S-(1,2-dichlorovinyl)-L-cysteine (DCVC) which accumulates in the proximal tubules. The genotoxicity of TCE and DCVC have been evaluated in vivo using the comet assay to assess DNA breakage in the proximal tubules of rat kidneys. Rats were exposed to TCE by inhalation or to DCVC by oral gavage at dose levels in excess of those which produced effects in long-term bioassays…

Comparative evaluation of genotoxicity of captan in amphibian larvae (Xenopus laevis and Pleurodeles waltl) using the comet assay and the micronucleus test.

Captan (N-trichloromethylthio-4-cyclohexene-1,2-dicarboximide) is a fungicide used to inhibit the growth of many types of fungi on plants used as foodstuffs. The toxic and genotoxic potentials of captan were evaluated with the micronucleus test (MNT; AFNOR,2000) and the comet assay (CA) using amphibian larvae (Xenopus laevis and Pleurodeles waltl). Acute toxicity results showed that captan was toxic (1) to Xenopus larvae exposed to from 2 mg/L to 125 or 62.5 microg/L, depending on the nature of the water [reconstituted water containing mineral salts or mineral water (MW; Volvic, Danone, France…

Evaluation of the mutagenic and genotoxic activities of anti-hepatitis B analogs of beta-L-adenosine by the Ames test and the Comet assay.

beta-L-2'-deoxyadenosine (beta-L-dA), beta-L-2',3'-dideoxyadenosine (beta-L-ddA) and its two bis (S-acyl-2-thioethyl; SATE) phosphotriester … genotoxicity of beta-LdA and the three other compounds was evaluated in human lymphocytes using the Comet assay, at doses up to 5 microg with or without the addition of a microsomal S9 fraction. None of the four compounds induced DNA strand breakage with and without metabolic activation. In summary, the data clearly demonstrate that the purine nucleoside beta …

Comet assay application in environmental monitoring: DNA damage in human leukocytes and plant cells in comparison with bacterial and yeast tests.

Urban airborne particulate is a complex mixture of air pollutants, many of which have not been identified. However, short-term mutagenesis t … and more qualitative than quantitative changes are evident. We also demonstrate the ability of the Comet assay to detect DNA-damaging agents in airborne particulate samples. We applied the test to human leukocytes and, with major improvements, to plant cells (Allium cepa roots and epigean tissues of Impatiens balsamina). The first findings on human leukocyte …

Leucocytes isolated from simply frozen whole blood can be used in human biomonitoring for DNA damage measurement with the comet assay.

Preservation of human blood cells for DNA damage analysis with the comet assay conventionally involves the isolation of mononuclear cells by centrifugation, suspension in freezing medium and slow freezing to -80 °C-a laborious process. A recent publication (Al-Salmani et al. Free Rad Biol Med 2011; 51: 719-725) describes a simple method in which small volumes of whole blood are frozen to -20 or -80 °C; on subsequent thawing, the comet assay is performed, with no indication of elevated DNA strand breakage resulting from the rapid freezing. However, leucocytes in whole blood (whether fresh or fr…

Occupational genotoxicity in agricultural workers exposed to pesticides in western Mexico: a comet assay-based biomonitoring study in Venustiano Carranza, Michoacán.

Occupational exposure to pesticides has been extensively studied in the last decades. Mexico, as an emerging nation, but also as an agricultural and horticultural country, has still scarce data. This is the first study in municipality of Venustiano Carranza, Michoacán, western Mexico, performed to study the DNA damage level in peripheral blood leukocytes of a group of 15 agricultural field workers occupationally exposed to pesticides and 14 non-exposed controls from the same region. Data was collected through structured surveys and analysis using the alkaline version of the comet assay. Result…

Comet Assay to Quantify DNA Damage in FLT3 Mutant-expressing 32D Cells after Exposure to Type I and Type II FLT3 Inhibitors.

FMS-like tyrosine kinase 3 (FLT3), a class III receptor tyrosine kinase, exhibits a mutation frequency of approximately 30% in acute myeloid leukemia (AML) patients and constitutes a critical therapeutic target. As representative type I and type II FLT3 inhibitors, respectively, gilteritinib and Quizartinib (AC220) are clinically employed in FLT3-mutant AML management. Gilteritinib inhibits both activated and inactivated FLT3 proteins, with additional inhibition of AXL targets to help overcome resistance. AC220 inhibits activated FLT3. The comet assay was systematically employed to quantify an…

Окисляющая ДНК Повреждение и Ремонт Динамики Множественного Склероза: Отчёты от кометы Ассей Кинетика, Ремонт Гены и Генотипный анализ.

Множественный склероз (MS) — нервно-воспалительное заболевание, при котором окислительный стресс и повреждения ДНК могут влиять на прогрессию болезни. Мы изучили вопрос о том, способствуют ли дефекты в проведении операций по обрезанию оснований (BER) MS благодаря сочетанию функциональных анализов по ремонту ДНК, профилирования экспрессии генов и анализа генотипов. Мы собрали периферийные кровеносные моноядерные клетки у 70 пациентов MS и 61 здоровый контроль. Эти клетки подвергались воздействию окислительного стресса, вызванного терт-бутилом гидропероксидом (ТБГ), и за 60 минут были измерены к

Совпадение в аннотации оригинала
Multiple sclerosis (MS) is a neuroinflammatory disease where oxidative stress and DNA damage may influence disease progression. We investiga … ontrols. These cells were subjected to tert-butyl hydroperoxide (TBH)-induced oxidative stress, and comet assay kinetics were measured over a period of 60 min. Additionally, we quantified the mRNA expression of nine key BER genes and genotyped selected polymorphisms related to DNA repair capacity. Samples from MS patients exhibited significantly higher levels …

Assessment of Cell Cytotoxicity and Comet Assay on HER2/neu Positive Cell Line Due to 111In Auger Electrons as DNA-Targeting Radioimmunoconjugate.

BACKGROUND: Breast cancer Auger electron therapy is a growing field of study in radioimmunotherapy and oncology research. Trastuzumab, a hig … NLS-trastuzumab (3.7 MBq) at 37 ºC. The cytotoxicity of the three species was studied using MTT and comet assay was utilized DNA damage detection. RESULTS: A significant radiochemical purity for 111In-DTPA-NLS-trastuzumab (99.36% ± 0.30%, ITLC) at the DTPA:antibody ratio of 6.90 ± 0.34:1, was obtained. Significant cell viability difference was found for 111I …

A case-control study to detect the extent of DNA damage in oral lichen planus and oral lichenoid reactions using comet assay.

AIM: This study aims to quantify the extent of DNA damage in lymphocytes of patients with oral lichen planus (OLP) and oral lichenoid reactions (OLRs) using comet assay. METHODOLOGY: Lymphocytes from peripheral blood were subjected to alkaline comet assay. Comet length (CL), head diameter (HD), percentage of DNA in head, tail length (TL), percentage of DNA in tail, tail intensity, tail mean and tail moment were compared between study group (OLP and OLR) and control group using Student's t-test. Pearson's correlation coefficient was used to examine the linear association between the variables.…