Number Of Micronuclei Research Articles

Micronuclei in human peripheral blood and bone marrow as genotoxicity markers: A systematic review and meta-analysis.

Can human peripheral blood cells be used as a surrogate for bone marrow cells, in evaluating the genotoxic effects of stressors? We searched the Pubmed/Medline and PubChem databases to identify publications relevant to this question. Micronucleus formation was the genotoxicity endpoint. Three publications comparing exposed vs. non-exposed individuals are included in this analysis; the exposures were to ethylene oxide or ionising radiation (atomic bomb, thorotrast, or radioiodine therapy). Information was extracted on the types of exposure, the numbers of participants, and the micronucleus frequencies. Relative differences (odds ratios) and absolute differences (risk differences) in the numbers of micronuclei between exposed and non-exposed persons were calculated separately for individual cell types (peripheral blood and bone marrow). Random effects meta-analyses for the relative differences in cell abnormalities were performed. The results showed very small differences in the frequencies of micronuclei between exposed and non-exposed individuals, as measured in either peripheral blood or bone marrow cell populations, on both absolute and relative scales. No definite conclusion concerning the relative sensitivities of bone marrow and peripheral blood cells can be made, based on these publications.

Preliminary study of chromosome aberrations using Giemsa, two-colour fish, and micronucleus assays in lymphocytes of individuals living in elevated radon concentration areas.

The frequencies of unstable and stable chromosome aberrations and micronuclei were examined in peripheral blood samples from 10 individuals living in elevated radon concentration areas (Takandeang Village, Mamuju, Indonesia). Blood samples from 10 people living in Topoyo Village were used as a control group. For unstable chromosome aberration analysis, a dicentric chromosome assay was conducted using conventional Giemsa staining. Chromosomal painting of chromosomes 1 and 4 using the fluorescence in situ hybridisation technique was also applied to four subjects to assess the stable chromosome aberration. Our study showed no significant increases across all groups in dicentric and other unstable chromosome aberrations, such as rings and acentric fragments. Translocations were found in one person from Takandeang Village and two Topoyo Village inhabitants. The translocations found in the subjects from Takandeang Village were due more to aging factors than to radon exposure. The number of micronuclei per 1000 binucleus cells in Takandeang Village inhabitants was not significantly different than that in the control group (p=0.943). A more comprehensive analysis should be conducted in a subsequent study by increasing the number of study donors and the number of metaphases to be analysed in both dicentric chromosome assay and fluorescence in situ hybridisation assays. Such research could provide valid information on the cytogenetic effects of elevated indoor radon exposure.

Assessment of Cytotoxic and Genotoxic Effect of Modern Dental Materials in vivo.

The aim of the study was to assess the biocompatibility of modern composite and amalgam dental fillings. The research was conducted on 150 healthy patients between the ages of 10 and 20 who had amalgam and composite fillings between 6 and 12 months. Under in vivo conditions, a swab of buccal cells near the fillings was taken, and the cytotoxic and genotoxic impact of composite and amalgam fillings on these cells was analyzed using the extended micronucleus test (cytomeassay). The results showed statistically significant differences between the groups of subjects with amalgam and composite fillings and subjects without fillings for the following parameters: number of micronuclei (p=0.006), number of buds (p<0.001), number of binuclear cells (p<0.001), number of nucleoplasmic bridges (p<0.001).The number of micronuclei was statistically significantly higher in the group of subjects with amalgam and composite fillings compared to the group without fillings. The results for nuclear buds, for the number of binuclear cells and the number of nucleoplasmic bridges showed that the group with amalgam fillings had a statistically significantly higher number of these changes compared to other groups.The results of the analysis of the relationship between the parameters of the micronucleus test and the number of amalgam and composite surfaces did not show statistically significant values. Parameters indicating cell cytotoxicity were not statistically significantly elevated in subjects with fillings. The results of the analysis of the influence of the patients' lifestyle on the results of the micronucleus test showed statistically significant results for certain predictors (diagnostic X-ray radiation, coffee consumption, consumption of cooked, dried meat and baked food). Based on the results, it can be concluded that the buccal cells of subjects with amalgam fillings showed the highest degree of genotoxic changes, followed by those with composite fillings and the least buccal cells of patients without fillings.

The Use of Multiple Biomarkers to Assess the Health of Anuran Amphibians in the Brazilian Cerrado Savanna: An Ecotoxicological Approach.

Changes in the natural landscape and the indiscriminate use of pesticides can have a major impact on aquatic environments and have contributed to the worldwide decline of amphibian populations. In the present study, we sampled tadpoles of three anuran amphibians (Boana albopunctata, Physalaemus cuvieri, and Dendropsophus minutus) from ponds in six different agricultural landscapes of the Brazilian Cerrado savanna and evaluated whether and to what extent genotoxic and mutagenic damage was related to land use (the amount of forest and agricultural remnants, and related physicochemical factors) and the presence of pesticides in the water of the study ponds. We also evaluated the hepatotoxicity in P. cuvieri, which was the most abundant species at five of the six sampling points. Clomazone and atrazine were the most common pesticides found in the ponds. The B. albopunctata and P. cuvieri tadpoles presented similar patterns of DNA damage among the sampling points. The least DNA damage was found in the D. minutus tadpoles, although this species was present in only one of the study ponds. More binucleated and anucleated cells were observed in B. albopunctata, but there was no significant variation among species in terms of the number of micronuclei or other erythrocytic nuclear abnormalities. Land use and physicochemical factors did not explain the variation in the DNA damage observed in the three anurans. The hepatotoxicity analyses of P. cuvieri revealed the presence of a series of alterations, including the enlargement of the sinusoids, vacuolization of the hepatocytes, the infiltration of inflammatory cells, hepatic steatosis, and dilation of the blood vessels. The interaction between physicochemical factors and the biomarkers analyzed in the present study is complex. In particular, it will be important to better elucidate which factors are contributing, either directly or indirectly, to the decline of anuran amphibian populations, especially in threatened biomes, such as the Brazilian Cerrado. In this case, we would encourage further in situ studies that assess the ecotoxicology of the landscape, together with the systematic monitoring of aquatic environments, to guarantee the long-term integrity of amphibian populations, and those of other organisms that play an essential functional role in the ecosystem. Environ Toxicol Chem 2023;00:1-18. © 2023 SETAC.

Biological response to the continuous occupational exposure to antineoplastic drugs and radionuclides

Purpose Antineoplastic drugs and radioiodine are recognized occupational risk factors affecting the genetic material of exposed persons. To assess cytogenetic damage and evaluate the presence of chromosomal instability during occupational exposure, a biomonitoring study was performed using a chromosomal aberration assay and a cytokinesis-block micronucleus (CBMN) test. Materials and Methods Blood samples from 314 healthy donors divided into 3 groups (control, exposed to antineoplastic drugs and exposed to radioiodine) were collected and cytogenetically analyzed. Results There was an increase in almost all analyzed parameters registered in the exposed persons. Chromatid breaks were higher in the subjects exposed to antineoplastic drugs, while dicentrics and premature centromere division (PCD) parameters were higher in nuclear medicine workers. The total number of micronuclei was higher in both groups of the exposed. The correlation analysis indicated the association of dicentrics, acentrics, chromosome and chromatid break with PCDs in both groups of the exposed, and micronuclei and nucleoplasmic bridges with PCDs in the subjects exposed to radioiodine. The discriminant analysis marked off PCD1-5 as the best predictor of exposure. Age, sex, sampling season and duration of exposure significantly influenced the analyzed parameters, while smoking habits did not show any influence. Conclusion Based on the observed results, premature centromere division can be considered a valuable parameter of genotoxic risk for individuals occupationally exposed to low doses of ionizing radiation.

Cytogenetic Study and Pollen Viability of Phalaenopsis Queen Beer 'Mantefon'.

Intergeneric and interspecific hybridization has been employed for the breeding of Phalaenopsis to transfer desirable traits between species, producing novel phenotypes with improved size, color, form, and flower-bearing ability. These characteristics are often enhanced; however, many of these hybrids are triploids and have reduced or complete sterility, for example, Phalaenopsis Queen Beer 'Mantefon', an important novelty-type cultivar in Asia, particularly in China, Japan, and Republic of Korea. Despite the increasing demand for the crop for ornamental purposes, little is known about its cytogenetics, which is essential for breeding and, consequently, crop improvement. In this study, karyotyping using fluorescence in situ hybridization, meiotic chromosome behavior analysis, pollen staining, and in vitro viability germination tests were performed to understand the cause of hybrid sterility and pollen abnormality in Phalaenopsis Queen Beer 'Mantefon' from a cytogenetic perspective. Viability tests revealed pollen infertility at all flower developmental stages, confirmed by the absence of pollen tube growth. Aberrant chromosomal behavior was observed in pollen mother cells (PMCs), frequently forming univalents, chromosomal bridges, and laggards during the entire meiotic process. PMCs were also divided irregularly into sporads with varying numbers of micronuclei, which may be responsible for pollen sterility in this cultivar. Altogether, the cytogenetic analyses provided insights into the pollen development of Phalaenopsis Queen Beer 'Mantefon' and the conceivable causes of its infertility.

The effect of exposure to radiofrequency LTE signal and coexposure to mitomycin-C in Chinese hamster lung fibroblast V79 cells.

This study aims to investigate the cellular effects of radiofrequency exposure, 1950 MHz, long-term evolution (LTE) signal, administered alone and in combination with mitomycin-C (MMC), a well-known cytotoxic agent. Chinese hamster lung fibroblast (V79) cells were exposed/sham exposed in a waveguide-based system under strictly controlled conditions of both electromagnetic and environmental parameters, at specific absorption rate (SAR) of 0.3 and 1.25 W/kg. Chromosomal damage (micronuclei formation), oxidative stress (reactive oxygen species [ROS] formation), and cell cycle progression were analyzed after exposure and coexposure. No differences between exposed samples and sham-controls were detected following radiofrequency exposure alone, for all the experimental conditions tested and biological endpoints investigated. When radiofrequency exposure was followed by MMC treatment, 3 h pre-exposure did not modify MMC-induced micronuclei. Pre-exposure of 20 h at 0.3 W/kg did not modify the number of micronuclei induced by MMC, while 1.25 W/kg resulted in a significant reduction of MMC-induced damage. Absence of effects was also detected when CW was used, at both SAR levels. MMC-induced ROS formation resulted significantly decreased at both SAR levels investigated, while cell proliferation and cell cycle progression were not affected by coexposures. The results here reported provide no evidence of direct effects of 1950 MHz, LTE signal. Moreover, they further support our previous findings on the capability of radiofrequency pre-exposure to induce protection from a subsequent toxic treatment, and the key role of the modulated signals and the experimental conditions adopted in eliciting the effect.

Anticancer effects of phytol against Sarcoma (S-180) and Human Leukemic (HL-60) cancer cells.

Phytol (Pyt), a diterpenoid, possesses many important bioactivities. This study evaluates the anticancer effects of Pyt on sarcoma 180 (S-180) and human leukemia (HL-60) cell lines. For this purpose, cells were treated with Pyt (4.72, 7.08, or 14.16 μM) and a cell viability assay was performed. Additionally, the alkaline comet assay and micronucleus test with cytokinesis were also performed using doxorubicin (6 μM) and hydrogen peroxide (10 mM) as positive controls and stressors, respectively. Results revealed that Pyt significantly reduced the viability and rate of division in S-180 and HL-60 cells with IC50 values of 18.98 ± 3.79 and 1.17 ± 0.34 μM, respectively. Pyt at 14.16 μM exerted aneugenic and/or clastogenic effects in S-180 and HL-60 cells, where the number of micronuclei and other nuclear abnormalities (e.g., nucleoplasmic bridges and nuclear buds) were frequently observed. Moreover, Pyt at all concentrations induced apoptosis and showed necrosis at 14.16 μM, suggesting its anticancer effects on the tested cancer cell lines. Taken together, Pyt showed promising anticancer effects, possibly through inducing apoptosis and necrosis mechanisms, and it exerted aneugenic and/or clastogenic effects on the S-180 and HL-60 cell lines.

Abstract B067: CRM1 inhibitor selinexor induces DNA damage repair-related vulnerability in prostate cancer cells

Abstract Background: Advanced metastatic prostate cancer is the second leading cause of death in men in the United States. Androgen deprivation therapy has been used as a front-line therapy; however, despite initial success, it fails subsequently and results in the development of castration-resistant prostate cancer. Due to these unmet therapeutic needs, there is an urgency to identify novel targets to develop next-generation therapeutics. Chromosome region maintenance 1 (CRM1) is one of the seven members of mammalian export proteins that function to export the proteins using nuclear export signal (NES). Several tumors, including prostate cancer, overexpress CRM1 to efflux tumor suppressor proteins to the cytoplasm and exhibit dysregulated nuclear export. CRM1-mediated export can lead to functional inactivation of p53, cyclinD1, p16, p21, and p27. Essential DNA repair proteins such as Rad51 and BRCA1 exhibit leucine-containing hydrophobic residues rich in NES and are known to be shuttled by CRM1. Based on this, we hypothesize that CRM1 inhibition may affect the expression, kinetics, localization, and stability of DNA repair network proteins. Methods: Androgen receptor-positive and negative prostate cancer cells were treated with Selinexor. The dose of the drug and duration was dependent on the endpoint measurement. Cell death was monitored using MTT assay and western blot measurement of cleaved PARP. Total RNA and cell lysate were collected to measure the relative levels of BRCA-1, RAD51, p53, and other members of the DNA repair pathway (HR and NHEJ). DNA damage was estimated using the number of micronuclei and immunofluorescence staining for γ-H2AX and COMET assay. Results: Selinexor treatment in prostate cancer cells affects the functioning of the DNA repair network and can be combined with inhibitors of DNA repair proteins. Citation Format: Rajendra Kumar, Janet Mendonca, Yuhan Yang, Abhishek Shetty, Lillian Wilson, Kavya Boyapati, Deven Topiwala, Keerti Soundappan, Eleni Panagopoulos, Michael Carducci, Sushant Kachhap. CRM1 inhibitor selinexor induces DNA damage repair-related vulnerability in prostate cancer cells [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr B067.

Utility of morphological markers of chromosomal instability in breast cytology- A study of 100 cases.

Carcinogenesis is associated with multiple mutations that lead to chromosomal instability (CIN). Our aim was to study the role of markers of CIN on breast cytology and correlate with histopathological diagnosis. A retrospective observational study was conducted over a year on 100 breast cytology cases. Leishman-stained smears were examined for the number of micronuclei (MN), chromatin bridge (CB), and multipolar mitosis (MPM). MNs were counted manually in 1,000 cells under oil immersion (1000×). The frequency of CB and MPM was also noted. The malignant cases were graded as low (grades 1 and 2) and high (grade 3). The mean age of the patients was 43.47 ± 15.81 years. The mean MN score for fibroadenoma cases was 4.54 (±1.5) and for malignant cases was 29.32 (±8.15). The receiver-operator curve (ROC) curve analysis confirmed >9 MN score as 100% specific and 100% sensitive for malignancy (area under the curve [AUC] =1). A significant comparison was noted between the mean MN of benign and malignant cases (P < 0.000001). The mean MN score for low-grade cases was 26.64 (±5.85) and for high-grade cases was 33.68 (±5.85) with a significant difference observed on comparing the population mean MN with a grade of malignancy (P-value = 0.01886). The difference between the frequencies of CB in low and high-grade cases was also found to be significant (P-value = 0.04135). The presence and scoring of markers of CIN (MN, CB, and MPM) on breast cytology have potential significance in the diagnosis of breast lesions.

THE ROLE OF ANTHROPOGENIC DERMATOTOXICANTS IN THE FORMATION OF ACNE IN ADOLESCENTS

Abstract. Against the background of the steady pace of urbanization, the negative impact of anthropogenic toxic substances on human health is increasing every year. The most sensitive to the action of ecotoxicants is the child and adolescent organism. Given the acute reaction of the skin to the influence of toxic chemicals, aggravated by humoral changes in the body during puberty, the identification of criteria for the toxic etiology of acne is certainly relevant.&#x0D; The aim of the study was to determine the criteria of the predominantly toxicological mechanism of acne formation.&#x0D; To assess the effect of anthropogenic dermatotoxicants on the formation of acne, 595 children and various districts of the Moscow region were examined, of which 301 adolescents suffered from acne, and 294 practically healthy children made up the control group. The study used spectrometric, cytogenetic, biochemical and immunological research methods. The content of essential and toxic trace elements in adolescent hair samples was evaluated. A micronuclear test was performed in buccal epithelial cells. The testosterone level and the immunoregulatory index were evaluated.&#x0D; The results obtained in the study indicate at least two mechanisms of the formation of acne vulgaris in adolescents. The first is associated with a violation of the regulation of sex hormones, and the second with the dermatotoxicity of anthropogenic ecotoxicants. Adolescents with predominantly intoxicating etiology were characterized by low concentrations of selenium and zinc, high mercury and lead in hair samples, as well as an increase in the number of micronuclei in the buccal epithelium. Adolescents with predominantly hormonal etiology were characterized by an increase in testosterone levels and a decrease in the immunoregulatory index. At the same time, in adolescents with signs of genetic instability determined by the results of a micronucleus test, the clinical course of acne was significantly more severe than in children without pronounced karyopathology. Based on statistical processing of these data, prognostic algorithms were built to differentiate acne in adolescents by etiological factor.&#x0D; Thus, anthropogenic chemical toxicants, represented mainly by heavy metal salts, have an aggravating effect on the formation and course of acne in adolescents.

The relationship of the efficiency of energy conversion into growth as an indicator for the determination of the optimal dose for mutation breeding with the appearance of chromosomal abnormalities and incomplete mitosis after gamma irradiation of kernels of Triticum turgidum ssp. durum L.

The study aim was to determine the optimal gamma irradiation dose for mutation breeding in Triticum turgidum ssp. durum L. Root, shoot and seedling growth, as well as the efficiency of energy conversion into growth were determined to examine the growth retardation effects of gamma irradiation that are the result of DNA damage (bridges, ring chromosomes, micronuclei, incomplete mitosis) in Triticum turgidum ssp. durum L. The kernels were irradiated with doses of 50, 150, 250 and 350 Gy using a 60Cobalt gamma-ray source. The kernels were placed in germination paper at 25 °C to grow for a 132 h period for the determination of shoot and root growth and the efficiency of energy conversion into growth. Root tips were collected and fixated over a 47.5 h growth period for the determination of the chromosomal abnormalities and incomplete mitosis. The control differed highly significantly (p < 0.01) from irradiated samples at all doses in root growth and from 250 to 350 Gy samples in shoot growth and the efficiency of energy conversion into growth. There was a highly significant (p < 0.01) increase in the number of bridges and micronuclei between 50 Gy samples and samples irradiated with the higher irradiation doses while 50 Gy samples differed only from 250 and 350 Gy samples regarding ring chromosomes and interphase cells with incomplete mitosis. Root and seedling growth on the one hand and the efficiency of energy conversion into growth on the other were found to be measuring different effects of gamma irradiation on plant growth. The latter was used for the determination of the optimal dose for mutation breeding as 155.52 Gy.

A Histochemical Comparison of Feulgen and Papanicolaou Stains in Demonstrating Cytotoxic and Genotoxic Effects of Cigarette Smoking on Human Buccal Mucosa Cells

Background: Different histochemical stains have been applied to demonstrate the cytotoxic and genotoxic effects of cigarette smoking on cells. Feulgen and Papanicolaou were the most popular stains to demonstrate nuclear abnormalities. The aim of this study was to compare Feulgen and Papanicolaou stains in demonstrating the cytotoxic and genotoxic effects of cigarette smoking on exfoliated oral mucosa cells. Methods: A total of 31 cigarette smokers and 15 non-smokers were included in this case-control study. Using a wooden spatula, two samples were taken from each participant. The samples from the left buccal mucosa were stained with Feulgen and the right mucosa with Papanicolaou. The mean number of micronuclei and the number of cells with pyknosis, karyorrhexis, and karyolysis were determined on Feulgen and Papanicolaou-stained slides. The number of counted cells with pyknosis, karyorrhexis, and karyolysis in 1000 cells/subject was recorded. The mean number of micronuclei was determined by the number of counted micronuclei per 1000 cells per subject. Results: The number of micronuclei was not significantly different between Feulgen and Papanicolaou stained samples (P=0.27). Demonstration of karyolysis (P=0.73) and karyorrhexis (P=0.24) was not significantly different between Feulgen and Papanicolaou staining methods. The Feulgen was significantly more effective in demonstrating pyknosis compared to Papanicolaou (P=0.02). Conclusions: Feulgen and Papanicolaou stains had similar effectiveness in demonstrating DNA alterations (micronucleus) and cellular death features (karyorrhexis and karyolysis). Feulgen was preferable to display pyknosis than Papanicolaou.

Morphological Changes and Apoptosis of Buccal Mucosa Basal Epithelium in Heads and Necks during Cancer Radiotherapy

Background: Radiotherapy is generally used to treat head and neck malignancy through high radiation, focusing on killing cancer cells. However, some adverse effects in oral mucosal tissue, including cell morphology changes and apoptosis, are commonly found. This study aims to determine the morphological changes and apoptosis of buccal mucosa epithelium after radiotherapy in head and neck cancer (HNC) patients.Methods: This study involved 8 subjects of patients diagnosed with HNC. Buccal mucosal smear samples were collected using cytobrush two times, before and after radiotherapy, with a dose of 70 Gy in 7 weeks. The specimens were prepared and stained using Feulgen and Rosenbeck technique. Observations were made using a light microscope with a count per 1000 epithelial cells. Statistical analysis was performed using statistical software with Pearson’s correlation test and significance t-test (p &lt; 0.05) between irradiated and non-irradiated samples.Results: Data analysis showed significant changes in cell morphological damage and apoptosis in patients before and after radiotherapy. It increases in the number of micronuclei (p = 0.001), broken egg (p = 0.001), binuclei (p = 0.003), pyknosis (p = 0.033), karyorrhexis (p = 0.020), and karyolysis (p = 0,004). Conclusions: The effects of radiation reflect morphological changes and apoptosis in the buccal mucosa basal epithelium in HNC patients.

The possible cytotoxicity and genotoxicity assessment of indaziflam on HepG2 cells.

The use of pesticides in farmland has increased considerably to protect crops against pests, weeds, and diseases. However, pesticides and/or their residues in ecosystems may affect non-target organisms. Indaziflam is a widely used herbicide in agricultural areas in the southern region of Turkey. Therefore, this study aimed to investigate the possible genotoxic and cytotoxic effects of indaziflam on HepG2 cells using comet assay, micronucleus assay, and xCELLigence. The HepG2 cells were treated with various concentrations of indaziflam for different duration of time based on xCELLigence results. Accordingly, the cells were incubated with indaziflam at final concentrations of 1, 5, 10, 20, 40, and 80μg/mL for 96h for cytotoxicity assay. To assess genotoxicity, cells were treated with indaziflam at final concentrations of 10, 40, and 100μg/mL for 4 and 24h. Ethanol was used as a solvent for indaziflam. Hydrogen peroxide (40μM) was used as a positive control. Studies have revealed that indaziflam did not show a statistically cytotoxic effect at the tested doses. Nevertheless, genotoxicity studies showed that indaziflam induced both DNA strand breaks and micronucleus numbers depending on the exposure time and dose.

Assessment of the Genotoxic and Cytotoxic Effects of Turpentine in Painters.

Turpentine is a fluid used mainly as a solvent for thinning oil-based paints, obtained by distilling the resin of coniferous trees. Fine art painters use turpentine on a daily basis. The aim of this study was to investigate the genotoxic effect of turpentine and to determine the lymphocyte proliferation index in the peripheral blood of individuals occupationally exposed to turpentine. For this purpose, the cytokinesis-block micronucleus assay (CBMN) was used to determine the total number of micronuclei (MNi), nucleoplasmic bridges (NPB), and nuclear buds (NBUD), as well as the cell proliferation index (CBPI) in the peripheral blood lymphocytes of the subjects. Twenty-two subjects exposed to turpentine daily through their work participated in the study and were compared to twenty subjects in the control group. The results showed a significant increase in the number of micronuclei and other genotoxicity parameters, as well as significant cytotoxicity based on CBPI values. In addition, the genotoxic and cytotoxic effects of turpentine were found to be time-dependent, i.e., the deleterious effects of turpentine on genetic material increase with prolonged exposure. These results strongly suggest that exposure to turpentine vapors may affect genome stability and that occupational safety measures should be taken when using turpentine.

Improvement of Proton Irradiation Effectiveness of Human Lung Carcinoma Cells A 549 in the Presence of Gold Nanoparticles

Purpose: To study was to study the effect of GNP nanoparticles on tumor cells of human lung carcinoma A 549 when irradiated with protons.&#x0D; Materials and methods:&#x0D; Cell culture: Human lung carcinoma cells A 549.&#x0D; Gold nanoparticles Au/PEG 6000/W 200/30 nm: A colloidal solution of gold nanoparticles purchased from the firm M 9 Nanomaterials &amp; Technologies was used in the work.&#x0D; Proton irradiation: The irradiation of cells was carried out on a therapeutic proton beam in the Medical and Technical Complex of the Laboratory of Nuclear Problems Joint Institute for Nuclear Research.&#x0D; Determination of radiosensitivity of cells: By determining the clonogenic survival of cells.&#x0D; Determination of the genotoxic activity of nanoparticles under the action of proton irradiation: investigated using a micronucleus test with blocking cytokinesis. The genotoxicity of gold nanoparticles was estimated by the number of micronuclei per 1000 binuclear cells. Micronucleus were counted only in binuclear cells. At least 1000 binuclear cells were calculated for each dose, experiments were carried out in three repeats.&#x0D; Results: The frequency of micronucleus formation indicates an increase in the genotoxic effect of nanoparticles when irradiated with protons at a dose of 2 Gy. Proton irradiation caused an increase in the frequency of micronucleus formation depending on the concentration of nanoparticles. When irradiated with protons at a dose of 2 Gy in the presence and absence of nanoparticles, the difference in the frequency of micronucleus formation for the concentration of nanoparticles was 2.5 mg/ml – 1.1; for 5 mg/ml and 10 mg/ml – 1.2; for 15 mg/ml – 1.3 and for 30 mg/ml –1.5. Cell survival curves reflect a decrease in their survival rate when metal nanoparticles with high Z are added, which reflects the occurrence of radiosensitization effects. The gain for 10 % and 50 % survival rates is 1.4 and 2.5, respectively.&#x0D; Conclusions: Under the influence of proton irradiation, the genotoxic activity of gold nanoparticles in human lung carcinoma cells A 549 increases, depending on their concentration. The survival rate of human lung carcinoma A 549 cells irradiated with protons in the presence of gold nanoparticles decreases.

Appraisal of acute and chronic arsenic exposure in differently exposed school children with special reference to micronuclei formation in urine epithelial cells: A comparative study in West Bengal, India

Arsenic (As) contaminated dietary intake in daily routine can bring serious health hazards even in children. Considering drinking water ingestion and rice-grain consumption pattern, the daily dietary intake rate of As through drinking water for the exposed children was observed as 17.5 μg/kg bw/day, greater than apparently control group of children (0.2 μg/kg bw/day). Biological samples such as urine, hair and nail for the exposed children showed higher accumulation of As (159 μg/l, 3320 μg/kg and 4460 μg/kg) compared to controlled children (1.92 μg/l, 195 μg/kg and 331 μg/kg). Arsenic toxicity can eventually lead to future cancer risk which is sub-clinically manifested through biological samples along with formation of micronuclei in urine epithelial cells of the affected children. Notably, according to unpaired t-test, the detected numbers of micronuclei were significantly higher in the urine epithelial cells of exposed school children (3.25/1000 epithelial cells) compared to the control children (0.52/1000 epithelial cells). ‘Severity Adjusted Margin of Exposure’ (SAMOE) value also corresponds to the huge amount of risk (class 5) through drinking water consumption. Rice-grain samples from households and mid-day meal samples also fall under the category of Class 4 in exposed area during the risk thermometer study. The average future cancer risk to the school children from the exposed area was found to be 1 × 10−3, 0.4 × 10−3, and 1.4 × 10−3, whilst the control group belongs to an apparently lower cancer risk zone such as 0.016 × 10−3, 0.4 × 10−3, and 0.012 × 10−3 during the intake of domestic tube-well water, rice-grain and school tube-well water, respectively. Simultaneously, non-cancer risk from drinking water is much lower in control children; however, rice-grain poses similar amount of risk for both groups (0.3–2.2). Hence, corrective measures are required for the management of contaminated water along with cooking malpractices.

Avaliação da estabilidade genômica de células da medula óssea de cães com leishmaniose visceral naturalmente infectados

ABSTRACT The aim of this article is to identify and evaluate the genomic stability of visceral leishmaniasis in naturally infected dogs. A total of 32 dogs participated in the study, 24 of which were asymptomatic animals, naturally infected, and 8 uninfected, used as a control group. The comet and micronucleus assay tests were performed on bone marrow cells obtained by means of aspiration puncture. For data analysis, the Shapiro-Wilk test was used to verify the normality of the data, and then the Mann-Whitney and T-tests for the comparison between the infected and control groups. The analysis of samples from naturally infected animals and healthy animals showed that the infection caused by the protozoan responsible for leishmaniasis was not able to induce DNA damage in the cells of the infected animals. In the results obtained through the micronucleus test, an increase in the number of micronuclei were observed in polychromatophilic erythrocytes in the medullary tissue of the infected group, when compared to the control group. As a main contribution, the results expressed in this study, consider that the comet and micronucleus assays are suitable for the biomonitoring of genomic stability in bone marrow cells of naturally infected dogs with visceral leishmaniasis.

Genotoxic and Cytotoxic Effects of Dental Radiographic Modalities on Buccal Mucosal Cells in Children

AbstractDental radiography is an important diagnostic tool for the detection and assessment of the extent of dental caries and accurate treatment planning. There is no safe limit for X-ray exposure. The associated risks of X-ray exposure are higher in children due to a higher rate of cell proliferation in them, compared with adults. This study aimed to assess the genotoxic and cytotoxic effects of dental radiographic modalities on buccal mucosal cells in children. This interventional study evaluated 80 children between 3 and 12 years who required periapical, panoramic, bitewing, or bitewing plus panoramic radiography for treatment planning. Twenty eligible patients were assigned to each of the aforementioned four groups. Buccal mucosal cells were scraped bilaterally by a plastic spatula after complete rinsing of the oral cavity. The collected specimens were directly mounted on microscopic slides and after air-drying, they were fixed with 80% methanol and Giemsa stain. The cells were then inspected under a light microscope at 400x magnification for cytogenetic changes. Data were tabulated and analyzed by SPSS version 20 at a p &lt; 0.001 level of significance. The results showed a significant increase in the frequency of karyolysis, karyorrhexis, and pyknosis in all four groups after dental radiography (p &lt; 0.001). Also, the number of micronuclei significantly increased after panoramic plus bitewing radiography (p &lt; 0.05). X-ray exposure in panoramic, periapical, bitewing, and bitewing plus panoramic radiographies can be cytotoxic, while bitewing plus panoramic radiography can be genotoxic in children as well.