China
Africa
Explore chapters and articles related to this topic
Approaches for Identification and Validation of Antimicrobial Compounds of Plant Origin: A Long Way from the Field to the Market
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
Lívia Maria Batista Vilela, Carlos André dos Santos-Silva, Ricardo Salas Roldan-Filho, Pollyanna Michelle da Silva, Marx de Oliveira Lima, José Rafael da Silva Araújo, Wilson Dias de Oliveira, Suyane de Deus e Melo, Madson Allan de Luna Aragão, Thiago Henrique Napoleão, Patrícia Maria Guedes Paiva, Ana Christina Brasileiro-Vidal, Ana Maria Benko-Iseppon
A second in vitro and in vivo test widely used in the analysis of candidate antimicrobial compounds is the chromosomal aberration test, by analyzing both structural and numerical changes scored in metaphase cells (FDA 2012; EMA 2013; Sekizawa et al. 2017). Structural chromosomal aberrations include chromosome gaps, breaks, deletion and other rearrangements like duplications, dicentrics, rings, isochromosomes, inversions and translocations. While the numerical changes result in disturbances or interferences in the chromosomal number at cell division, that can lead to cells bearing aneuploidy or/and polyploidy (Mosesso et al. 2019).
Radiation Carcinogenesis: Tissue Culture Model
Published in Kedar N. Prasad, Handbook of RADIOBIOLOGY, 2020
Based on numerous cellular and molecular biology studies, the following hypotheses of cancer have been proposed: Activation of protooncogenes.3,4Loss of antioncogenes.5Infection with certain viruses.6Substitution of normal promoters of protooncogenes with strong promoters of viruses.7Chromosomal aberrations.8b
Measurement of Exposure and Dose
Published in Samuel C. Morris, Cancer Risk Assessment, 2020
Some biochemical indicators may serve either as a measure of exposure or effect. Chromosome aberrations, for example, are an effect, but their meaningfulness as an earlier indicator of a carcinogenic effect is unclear. Their best purpose at present may be as a nonspecific measure of exposure to mutagenic agents. Even here, however, it must be recognized that the results may be influenced by infection or processes other than chemical exposure.
Evaluation of in vitro and in vivo genotoxic and antigenotoxic effects of Rhus coriaria
Published in Drug and Chemical Toxicology, 2021
Taygun Timocin, Mehmet Arslan, Hasan Basri Ila
Traditional use of RC fruit for many diseases and its properties were the inspiration for this work. In addition, there has been no previous research on the genotoxic and antigenotoxic properties of RC in the literature. The effects of a compound, product, and environmental factors on the genetic material of cells or organisms are determined by genotoxicity tests (Hagmar et al. 1994, Albertini et al. 2000, Liou et al.2002, Bonassi et al. 2007). Increases in CA and MN frequencies are considered biomarkers for cancer risk in humans (Hagmar et al.1998, Ginzkey et al.2014, Huerta et al.2014, Topaktas et al.2017). Although they vary among species, factors of in vivo metabolism, pharmacokinetics, and DNA repair processes are active and contribute to the response to genotoxic chemicals (OECD 2016). Therefore, an in vivo chromosome aberration test was used to detect structural chromosome aberrations. The mechanism of micronuclei is such that acentric fragments or whole chromosomes, which are unable to migrate to the cell poles with the rest of the chromosomes, appear as small nuclei in interphase cells. Thus, the presence of micronuclei is accepted as a sign for clastogenic and/or aneugenic effects of chemical substances (Giri et al.2002, Topaktas et al.2017, Ribeiro et al.2018). In addition, DNA strand breaks induced by oxidants are related to the prevention of cancer (Hiramoto et al.1993).
Evaluation of toxicological and antimicrobial activity of lavender and immortelle essential oils
Published in Drug and Chemical Toxicology, 2021
Aner Mesic, Irma Mahmutović-Dizdarević, Emina Tahirović, Irma Durmišević, Izet Eminovic, Anesa Jerković-Mujkić, Renata Bešta-Gajević
The chromosome aberrations (CAs) test was modified according to Moorhead et al. (1960). Lymphocyte cell cultures were incubated at 37 °C for 72 h. The test concentrations of lavender and immortelle EOs were added to lymphocyte cultures after 48 h of incubation at the following final concentrations: 0.10; 0.20, and 0.30 µl/ml and the cultures incubated for a further 24 h. The test concentrations of lavender and immortelle oils were prepared with 0.1% DMSO and RPMI-1640 medium. In order to arrest the cells at the metaphase stage, at 70 h of incubation, colcemid™ solution (0.2 µg/ml) (Sigma-Aldrich, St. Louis, MO) was added. In all of the experiments, DMSO (0.1%) was used as the solvent control, while untreated culture was the control group. After an incubation period of 72 h, the cells from culture were treated with a hypotonic solution (0.075 M KCl) for 30 min at 37 °C, to lyse the red blood cells, and fixed with a cold methanol/glacial acetic acid fixative (3:1 v/v). The fixation included three changes of the fixative. Pre-fixed lymphocytes were spread onto clean and cooled glass slides, air-dried, stained with 10% Giemsa solution and analyzed under 1000x magnification.
Oxidative protein modification and chromosomal instability among type 2 diabetics in Osogbo, Nigeria
Published in Alexandria Journal of Medicine, 2021
O.O. Olaniyan, O.O Odewusi, H.B Osadolor
Due to increased relative risk of morbidity and mortality among individuals with diabetes as compared with apparently healthy non-diabetes controls, diabetes can be viewed as a premature aging syndrome that affects the overall metabolic shift leading to genotoxic stress and loss of chromosomal integrity [8]. Alterations in genomic system occur when the process of oxidative DNA lesions/damage overwhelms the DNA repair mechanism, leading to accumulation of unrepaired damaged DNA in the system. Thus, chromosomal aberration can be described as the microscopically visible part of a wide spectrum of DNA changes generated by different repair mechanisms of DNA double strand breaks and it represents the biological consequences of human exposure to either ionizing or genotoxic agents or both [9]. Chromosomal aberrations can either be a numerical abnormalities (missing of whole chromosome or addition of extra chromosome to the normal pair) or structural abnormalities (when part of an individual chromosome is missing/extra switched to another chromosome/turned upside down) [10]. Structural chromosomal aberration (sCA) is a product of breakage and incorrect rejoining of chromosomal segments that resulting in varieties of disease conditions. Structural chromosomal aberration can either be balanced (the complete chromosomal set is still present after being rearranged, e.g. inversions, translocations) or unbalanced (after the rearrangement the complete chromosomal set is either missing or having an addition, e.g. deletions, duplications, insertions) [11].