In vitro effect of etching time and polymerization duration on the shear bond strengths to dentin

The effect of dentine etching time with H 3 PO 4 37% (20 and 60 sec) and composite polymerization duration (60 and 180 sec) on the shear bond strengths to dentin was evaluated in vitro. Dentine was treated with H 3 PO 4 37% in duration of 20 and 60 sec, before (Syntac ® ) was applied. The composite was polymerized for 60 and 180 sec. Data were analyzed with Anova and Tuckey test. Mean values for the first group (etching 20 sec / polymerization 60 sec) were 63.8 ± 3.7 N, for the second group (E 60 sec / P 60 sec) 111.7 ± 2.4 N, and for the third group (E 60 sec / P 180 sec) 132.8 ± 14.3 N. The control group (AdheSe ® ) had mean values 134.4 ± 15.5 N. There is significant difference found between the second and the first group (

Atmospheric pollution in Kosovo is associated with increased DNA damage in the human population

In order to assess DNA damage associated with exposure to environmental pollution in two polluted sites and one control site in Kosovo, whole blood samples were collected from volunteers in two polluted areas (Kastriot/ Obiliq - lignite-based power plants and lignite mines - and Drenas/Gllogovc - Ferronikeli smelting plant) as well as from Peja, representing an unpolluted area. White blood cells were isolated, and DNA damage was analyzed by the alkaline comet assay. Significantly higher levels of DNA damage (strand breaks) were found in white blood cells from subjects living in the polluted areas compared with residents of the unpolluted city, indicating a potential threat to human health.Avdulla J. Alija, Fisnik Asllani, Ismet D. Bajraktari, Andrew Richard Collins, Shemsedin Dreshaj, Nikolaus Bresgen, Peter M. Eck

The hCOMET project: International database comparison of results with the comet assay in human biomonitoring. Baseline frequency of DNA damage and effect of main confounders

The alkaline comet assay, or single cell gel electrophoresis, is one of the most popular methods for assessing DNA damage in human population. One of the open issues concerning this assay is the identification of those factors that can explain the large inter-individual and inter-laboratory variation. International collaborative initiatives such as the hCOMET project - a COST Action launched in 2016 - represent a valuable tool to meet this challenge. The aims of hCOMET were to establish reference values for the level of DNA damage in humans, to investigate the effect of host factors, lifestyle and exposure to genotoxic agents, and to compare different sources of assay variability. A database of 19,320 subjects was generated, pooling data from 105 studies run by 44 laboratories in 26 countries between 1999 and 2019. A mixed random effect log-linear model, in parallel with a classic meta-analysis, was applied to take into account the extensive heterogeneity of data, due to descriptor, specimen and protocol variability. As a result of this analysis interquartile intervals of DNA strand breaks (which includes alkali-labile sites) were reported for tail intensity, tail length, and tail moment (comet assay descriptors). A small variation by age was reported in some datasets, suggesting higher DNA damage in oldest age-classes, while no effect could be shown for sex or smoking habit, although the lack of data on heavy smokers has still to be considered. Finally, highly significant differences in DNA damage were found for most exposures investigated in specific studies. In conclusion, these data, which confirm that DNA damage measured by the comet assay is an excellent biomarker of exposure in several conditions, may contribute to improving the quality of study design and to the standardization of results of the comet assay in human populations

The hCOMET project: international database comparison of results with the comet assay in human biomonitoring (baseline frequency of DNA damage and effect of main confounders)

The alkaline comet assay, or single cell gel electrophoresis, is one of the most popular methods for assessing DNA damage in the human population. One of the open issues concerning this assay is the identification of those factors that can explain the large inter-individual and inter-laboratory variation. International collaborative initiatives such as the hCOMET project - a COST Action launched in 2016 - represent a valuable tool to meet this challenge. The aims of hCOMET were to establish reference values for the level of DNA damage in humans, to investigate the effect of host factors, lifestyle, and exposure to genotoxic agents, and to compare different sources of assay variability. A database of 19,320 subjects was generated, pooling data from 105 studies run by 44 laboratories in 26 countries between 1999 and 2019. A mixed random effect log-linear model, in parallel with a classic meta-analysis, was applied to take into account the extensive heterogeneity of data, due to descriptor, specimen, and protocol variability. As a result of this analysis interquartile intervals of DNA strand breaks (which includes alkali-labile sites) were reported for tail intensity, tail length, and tail moment (comet assay descriptors). A small variation by age was reported in some datasets, suggesting higher DNA damage in oldest age-classes, while no effect could be shown for sex or smoking habit, although the lack of data on heavy smokers has still to be considered. Finally, highly significant differences in DNA damage were found for most exposures investigated in specific studies. In conclusion, these data, which confirm that DNA damage measured by the comet assay is an excellent biomarker of exposure in several conditions, may contribute to improving the quality of study design and to the standardization of results of the comet assay in humans populations.info:eu-repo/semantics/publishedVersio

The hCOMET project: International database comparison of results with the comet assay in human biomonitoring. Baseline frequency of DNA damage and effect of main confounders

The alkaline comet assay, or single cell gel electrophoresis, is one of the most popular methods for assessing DNA damage in human population. One of the open issues concerning this assay is the identification of those factors that can explain the large inter-individual and inter-laboratory variation. International collaborative initiatives such as the hCOMET project - a COST Action launched in 2016 - represent a valuable tool to meet this challenge. The aims of hCOMET were to establish reference values for the level of DNA damage in humans, to investigate the effect of host factors, lifestyle and exposure to genotoxic agents, and to compare different sources of assay variability. A database of 19,320 subjects was generated, pooling data from 105 studies run by 44 laboratories in 26 countries between 1999 and 2019. A mixed random effect log-linear model, in parallel with a classic meta-analysis, was applied to take into account the extensive heterogeneity of data, due to descriptor, specimen and protocol variability. As a result of this analysis interquartile intervals of DNA strand breaks (which includes alkali-labile sites) were reported for tail intensity, tail length, and tail moment (comet assay descriptors). A small variation by age was reported in some datasets, suggesting higher DNA damage in oldest age-classes, while no effect could be shown for sex or smoking habit, although the lack of data on heavy smokers has still to be considered. Finally, highly significant differences in DNA damage were found for most exposures investigated in specific studies. In conclusion, these data, which confirm that DNA damage measured by the comet assay is an excellent biomarker of exposure in several conditions, may contribute to improving the quality of study design and to the standardization of results of the comet assay in human populations