In vitro assessment of clastogenicity of mobile-phone radiation (835 MHz) using the alkaline comet assay and chromosomal aberration test

2008 ◽  
Vol 23 (3) ◽  
pp. 319-327 ◽  
Author(s):  
Ji-Young Kim ◽  
Sae-Yong Hong ◽  
Young-Mi Lee ◽  
Shin-Ae Yu ◽  
Woo Suk Koh ◽  
...  
Keyword(s):  
Comet Assay ◽  
Mobile Phone ◽  
Chromosomal Aberration ◽  
Alkaline Comet Assay ◽  
In Vitro Assessment ◽  
Chromosomal Aberration Test ◽  
Mobile Phone Radiation

scholarly journals Comparison of methods used for evaluation of mutagenicity/genotoxicity of model chemicals - parabens

2020 ◽  
pp. S661-S679
Author(s):  
J Chrz ◽  
B Hošíková ◽  
L Svobodová ◽  
D Očadlíková ◽  
H Kolářová ◽  
...  
Keyword(s):  
Comet Assay ◽  
Chromosomal Aberration ◽  
Water Solubility ◽  
Consumer Products ◽  
Weight Of Evidence ◽  
In Vitro Tests ◽  
Genotoxic Potential ◽  
Chromosomal Aberration Test

Growing worldwide efforts to replace (reduce) animal testing and to improve alternative in vitro tests which may be more efficient in terms of both time, cost and scientific validity include also genotoxicity/mutagenicity endpoints. The aim of the review article was to summarize currently available in vitro testing approaches in this field, their regulatory acceptance and recommended combinations for classification of chemicals. A study using the combination of Comet Assay performed on two cell lines and the Chromosomal Aberration test on human peripheral lymphocytes was performed with the aim to predict the genotoxic potential of selected paraben esters, serving as a model chemical group. Parabens are widely used in consumer products as preservatives and have been reported to exhibit inconclusive results in numerous genotoxicity studies. The Comet Assay identified Ethylparaben and Benzylparaben as potentially genotoxic. The Chromosomal Aberration test revealed weak genotoxic potential in case of Ethylparaben and positive genotoxicity in case of Butylparaben, Propylparaben and Isopropylparaben. The main reasons for variability seem to be limited water solubility of parabens, determining their bioavailability at the cellular level, and absence of metabolic activation in the Comet Assay. The results confirmed that the Comet Assay should serve as a screening test and should not be used as a stand-alone method for classification of genotoxicity. The weight of evidence approach in risk assessment should be supported with data generated with the use of human relevant in vitro methods based on cells / tissues of human origin.

scholarly journals Synergistic Effect of Radiofrequency Electromagnetic Fields of Dental Light Cure Devices and Mobile Phones Accelerating Microleakage of Amalgam Restorations: An in vitro Study

2019 ◽  
Vol 9 (2Apr) ◽  
Author(s):  
S M J Mortazavi ◽  
A Dehghani Nazhvani ◽  
M Paknahad
Keyword(s):  
Mobile Phone ◽  
Electromagnetic Fields ◽  
Mobile Phones ◽  
In Vitro Study ◽  
Control Group ◽  
Human Teeth ◽  
Fourth Group ◽  
Mobile Phone Radiation ◽  
Amalgam Restorations

Background: Previous studies have shown that exposure to electromagnetic fields produced by magnetic resonance imaging or mobile phones can lead to increased microleakage of dental amalgam.Objective: The aim of the present study was to investigate the effect of electromagnetic field of a commercial dental light cure device and a common GSM mobile phone on microleakage of amalgam restorations.Materials and Methods: Identical class V cavities were prepared on the buccal surfaces of 60 non-carious extracted human teeth. The samples were randomly divided into 4 groups of 20 samples each. The samples in the first group were not exposed to electromagnetic fields, while the second and the third groups were exposed to electromagnetic fields produced by a commercial light cure device, or mobile phone radiation (60 min), respectively. The fourth group was exposed to electromagnetic radiations emitted by both mobile phone for 60 min and light cure device. Then, teeth samples were scored for microleakage according to a standard dye penetration protocol by examination under a stereomicroscope.Results: The mean score of microleakage in the fourth group (light cure + mobile phone) was significantly higher than that of the control group (P =0.030). Moreover, the scores of microleakage in this group were significantly higher than that of the second group (light cure only) (P= 0.043).Conclusion: Exposure of amalgam restorations to electromagnetic fields produced by both light cure devices and mobile phones can synergistically increase the microleakage of amalgam restorations.

scholarly journals In vitro assessment of the cytotoxic, DNA damaging, and cytogenetic effects of hydroquinone in human peripheral blood lymphocytes

2017 ◽  
Vol 68 (4) ◽  
pp. 322-335 ◽  
Author(s):  
Karlo Jurica ◽  
Irena Brčić Karačonji ◽  
Vesna Benković ◽  
Nevenka Kopjar
Keyword(s):  
Comet Assay ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Metabolic Activation ◽  
Peripheral Blood Lymphocytes ◽  
Alkaline Comet Assay ◽  
Blood Lymphocytes ◽  
Human Peripheral Blood Lymphocytes ◽  
Cytogenetic Effects

Abstract This study investigated the mechanisms of hydroquinone toxicity and assessed the relationships between its cytotoxic, genotoxic, and cytogenetic effects tested at 8, 140, and 280 μg mL-1 in human peripheral blood lymphocytes exposed for 24 h. The outcomes of the treatments were evaluated using the apoptosis/necrosis assay, the alkaline comet assay, and the cytokinesis-block micronucleus (CBMN) cytome assay. The tested hydroquinone concentrations produced relatively weak cytotoxicity in resting lymphocytes, which mostly died via apoptosis. Hydroquinone’s marked genotoxic effects were detected using the alkaline comet assay. Significantly decreased values of all comet parameters compared to controls indicated specific mechanisms of hydroquinone-DNA interactions. Our results suggest that the two higher hydroquinone concentrations possibly led to cross-linking and adduct formation. Increased levels of DNA breakage measured following exposure to the lowest concentration suggested mechanisms related to oxidative stress and inhibition of topoisomerase II. At 8 μg mL-1, hydroquinone did not significantly affect MN formation. At 140 and 280 μg mL-1, it completely blocked lymphocyte division. The two latter concentrations also led to erythrocyte stabilization and prevented their lysis. At least two facts contribute to this study’s relevance: (I) this is the first study that quantifies the degree of reduction in total comet area measured in lymphocyte DNA after hydroquinone treatment, (II) it is also the first one on a lymphocyte model that adopted the “cytome” protocol in an MN assay and found that lymphocytes exposure even to low hydroquinone concentration resulted in a significant increase of nuclear bud frequency. Considering the limitations of the lymphocyte model, which does not possess intrinsic metabolic activation, in order to unequivocally prove the obtained results further studies using other appropriate cell lines are advised.

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