Micronucleus Analysis Research Articles

Effect of ionizing radiation on the occupational health of radiologists

Objective To analyze peripheral blood hemogram, lymphocyte micronucleus and chromosomal aberrations of radiologists, so as to provide basis for occupational protection and health monitoring of radiologists. Methods Lymphocyte micronucleus, chromosome and blood hemogram analysis were performed on 127 radiologists who received health examinations in 2015, 2017 and 2019, and they were assigned to the radiation group. In addition, 133 medical staff with no history of radiation exposure were selected as the control group. Results The micronucleus rate and chromosome aberration rate of the radiation group were higher than those of the control group, and the white blood cell and platelet counts were lower than those of the control group, both of which were statistically significant ( P < 0.05). The total number of white blood cells in peripheral blood of 127 radiologists decreased gradually with the increase of exposure time to ionizing radiation, and the chromosome aberration rate increased gradually, all of which had statistical significance ( P < 0.05). The rate of chromosomal aberration was higher in radiologists with damage work age of more than 20 years than in the low-work age group, and there was no statistical significance between different damage work age ( P > 0.05). The chromosome aberration rate of nuclear medicine and interventional therapy was higher than that of other types, with statistical significance ( P < 0.05). Conclusion Long-term exposure to low-dose ionizing radiation can reduce the total number of white blood cells and increase the chromosome aberration rate of radiologists. It is necessary to strengthen the protective measures for radiologists to reduce the degree of ionizing radiation damage, especially to strengthen the occupational protection for radiologists in nuclear medicine and interventional therapy. 摘要： 目的 分析放射工作者外周血象、淋巴细胞微核及染色体畸变情况, 为放射工作者职业防护和健康监测提供依 据。 方法 对 2015 年、2017 年和 2019 年连续 3 次接受健康检查的 127 名放射工作者进行淋巴细胞微核、染色体及血 象分析, 将其设为放射组。另外选取 133 名无射线接触史的医务人员设为对照组; 结果 放射组中淋巴细胞微核率和 染色体畸变率高于对照组, 白细胞和血小板计数低于对照组, 均具有统计学意义 ( P < 0.05)。127 名放射工作者外周血 白细胞总数随着接触电离辐射时间的增长逐渐降低, 染色体畸变率逐渐增加, 均具有统计学意义 ( P < 0.05)。损害工龄 大于 20 年的放射工作者染色体畸变率高于低工龄组, 不同损害工龄之间比较无统计学意义 ( P > 0.05)。核医学与介入 治疗工种染色体畸变率高于其他工种, 具有统计学意义 ( P < 0.05)。 结论 长时间接触低剂量电离辐射可使放射工作 者白细胞总数降低和淋巴细胞染色体畸变率增加, 应加强放射工作者防护措施以备降低电离辐射损伤程度, 特别要加 强核医学和介入治疗放射工作人员的职业防护。

Validation of the hen's egg test for micronucleus induction (HET-MN): detailed protocol including scoring atlas, historical control data and statistical analysis.

A validation exercise of the hen’s egg test for micronucleus induction was finalised with a very good predictivity based on the analysis of micronuclei in peripheral erythrocytes of fertilised chicken eggs (Reisinger et al. The hen’s egg test for micronucleus-induction (HET-MN): validation data set. Mutagenesis, this issue). For transparency reasons this complementary publication provides further details on the assay especially as it was the first validation study in the field of genotoxicity testing involving the use of chicken eggs. Thus, the experimental protocol is described in detail and is complemented by a scoring atlas for microscopic analysis in blood cells. In addition, general characteristics of the test system, which is able to mirror the systemic availability of test compounds, are delineated: the test compound passes the egg membrane and is taken up by the blood vessels of the underlying chorioallantoic membrane. Subsequently, it is distributed by the circulating blood, metabolised by the developing liver and the yolk sac membrane and finally excreted into the allantois, a bladder equivalent. In specific, the suitability of the test system for genotoxicity testing is shown by, inter alia, a low background DNA damage in a comprehensive historical control database. In addition, the state-of-the-art statistical method used to evaluate obtained data is delineated. It combines laboratory-specific effect threshold with the Umbrella–Williams test, a statistical model also of interest for other genotoxicity test methods.

The hen's egg test for micronucleus induction (HET-MN): validation data set.

The classical in vitro genotoxicity test battery is known to be sensitive for indicating genotoxicity. However, a high rate of ‘misleading positives’ was reported when three assays were combined as required by several legislations. Despite the recent optimisations of the standard in vitro tests, two gaps could hardly be addressed with assays based on 2D monolayer cell cultures: the route of exposure and a relevant intrinsic metabolic capacity to transform pro-mutagens into reactive metabolites. Following these considerations, fertilised chicken eggs have been introduced into genotoxicity testing and were combined with a classical read-out parameter, the micronucleus frequency in circulating erythrocytes, to develop the hen’s egg test for micronucleus induction (HET-MN). As a major advantage, the test mirrors the systemic availability of compounds after oral exposure by reflecting certain steps of Absorption, Distribution, Metabolism, Excretion (ADME) without being considered as an animal experiment. The assay is supposed to add to a toolbox of assays to follow up on positive findings from initial testing with classical in vitro assays. We here report on a validation exercise, in which >30 chemicals were tested double-blinded in three laboratories. The specificity and sensitivity of the HET-MN were calculated to be 98 and 84%, respectively, corresponding to an overall accuracy of 91%. A detailed protocol, which includes a picture atlas detailing the cell and micronuclei analysis, is published in parallel (Maul et al. Validation of the hen’s egg test for micronucleus induction (HET-MN): detailed protocol including scoring atlas, historical control data and statistical analysis).

Morus alba Prevented the Cyclophosphamide Induced Somatic and Germinal Cell Damage in Male Rats by Ameliorating the Antioxidant Enzyme Levels.

Cytogenetic analysis is essential to determine the effect of mutagens and antimutagens on genetic material. This study was done to evaluate the protective effect of root bark extract of Morus alba (M. alba) against cyclophosphamide induced somatic and germinal cell damage in male rats. The ethanolic extract of M. alba (0.25, 0.5 and 1 g/kg, 2 weeks) was evaluated against cyclophosphamide (75 mg/kg, single dose) induced nuclear damage. The sampling was done after 48 h of the clastogen treatment. The somatic and germinal nuclear damage was studied by bone marrow micronucleus and sperm analysis, respectively. Serum superoxide and catalase levels were estimated to determine the antioxidant status in each group. The results were analyzed statistically to find the significant variation. The administration of M. alba for 2 weeks suppressed dose-dependently the changes induced by cyclophosphamide. M. alba (0.5 g/kg) decreased the frequency of micronucleated erythrocyte, sperm shape abnormality and enhanced the sperm count, sperm motility and polychromatic-normochromatic erythrocytes ratio significantly (p < 0.05) in comparison with the cyclophosphamide treated group. The highest tested dose of M. alba (1 g/kg) produced more prominent suppression (p < 0.01) in the cyclophosphamide-induced somatic and germinal cell defects. The results also showed significant (p < 0.05) improvement in the serum antioxidant enzymes levels with M. alba when compared with the challenge group. The lower dose of M. alba extract (0.25 g/kg) prevented the CP-induced changes but was found to be statistically insignificant. Therefore, antimutagenic potential of the high dose of the extract of M. alba is possibly due to its antioxidant nature. The ability of the M. alba extract to prevent the nuclear damage could play an important role in overcoming several mutational defects that are associated with anticancer chemotherapy.

Cytogenetic and Oxidative Status of Cultured Lymphocytes after Exposure to Extracts from Rhizopogon Mushrooms (Agaricomycetes) In Vitro.

In this study, acetone and water extracts obtained from edible mushrooms, Rhizopogon luteolus Fr. and Rh. roseolus (Corda) Th. Fr., containing important bioactive components were used. Total antioxidant capacity (TAC) and total oxidative stress (TOS) levels were examined on human peripheral lymphocyte culture treated with the respective extracts. Levels of genetic damage and cytotoxic effects of the respective extracts on lymphocytes were also tested. In general, when TAC levels of the extracts on cells were examined, a concentration-dependent increase was observed; a negative correlation was found between TOS data and concentration. Genotoxicity tests (chromosome aberration and micronucleus analysis) revealed that the concentrations of the extract applications did not significantly (P > 0.05) change genotoxicity on human peripheral lymphocyte culture compared to the negative control. Considering all of the results obtained, it was determined that applications of Rh. luteolus and Rh. roseolus extracts, especially at concentrations of 50 and 100 mg/L, increased the TAC value of lymphocytes, which play an important role in the human immune system, without causing genetic or oxidative stress.

Micronuclei analysis in people residing within 25 m of radiation-exposed areas around mobile towers in Chennai, India: An observational study

Aim and Objectives: Mobile towers are known to emit a radiofrequency (RF) radiation continuously, which increases the health concern of living beings. However, still the biological effect of exposure to RF remains controversial. The present study was performed to evaluate the presence of micronuclei (MN) in the exfoliated buccal cells due to the genotoxic effect of cell phone tower radiation. Materials and Methods: This is an observational study that was conducted with randomly selected n = 108 subjects between 5 and 50 years of age from three school-based localities in Chennai, which were located within the radius of 10–25 m around the mobile towers; exfoliated buccal cells were collected. A smear was made using the collected exfoliated buccal cells and analyzed for the presence of MN. The smear was stained using giemsa stain to evaluate the same. The collected data were statistically analyzed using Pearson’s chi-square test and Student’s T-test. Results: The study results showed that 55.05% of the study population had the presence of MN in at least one field (a total of 10 fields examined), and 45.95% did not have MN in their exfoliated cells examined. The presence of MN was more seen in the 0–10 age groups, with preponderance of the female population (P > 0.05) being statistically insignificant. Conclusion: The presence of MN can be considered as a prerequisite for environmental genotoxicity and adverse health risks due to constant exposure to RF radiation.

EVALUTING THE ABILITY OF PLEUROTUS OSTREATUS AQUEOUS EXTRACT TO MODULATE GENOTOXICITY INDUCED BY CYCLOPHOSPHAMIDE IN MICE BONE MARROW CELLS

This study was aimed to evaluate the ability of local oyster mushroom(Pleurotus ostreatus; ID: MF065715.1; cultivated until maturation in growth medium containing cumin extract) to modulate the genotoxicity induced by cyclophosphamide (CP) in bone marrow cells of mice. In vivo genotoxicity was assessed by quantifying the incidence of micronucleated polychromatic erythrocytes in the bone marrow cells of mice that were administered different doses of P.ostreatus extract (150, 200,250, and 300 mg/kg/day( respectively, individually, and in combination with CP (40 mg/kg body weight) according to the following three experimental protocols (pre 2h, post 2h, and concomitant treatment for 14 days, respectively). Analysis and microscopic examination of micronuclei (MN) revealed no mutagenic effect of P.ostreatus extract alone at all the doses evaluated. By contrast, CP administration significantly increased (P&lt;0.05) incidence of MN. Importantly, the co-administration of P.ostreatus extract with CP caused a significant and dose-dependent reduction in MN induced by CP in the murine bone marrow cells. These data suggest that P.ostreatus extract administration has a protective effect against genotoxic damage inflicted by CP. The dietary cumin may serve as a scavenger for free radicals generated by CP and may augment the antioxidant activity of P. ostreatus extract. These findings open up new avenues for the use of oyster mushrooms in many applications, including pharmacological preparations and food supplements.

THERAPEUTIC POTENCY OF SWEET ORANGE JUICE OVER LIVER GENOTOXICITY INDUCED BY PESTICIDE LANNATE IN RATS

Objective: The aim of the present investigation was to study the potential effect of sweet orange juice against liver genotoxicity induced by lannate.&#x0D; Methods: adult 36 female rats were divided into 6 groups: group C (control group), group L (lannate group) injected intraperitoneal (i. p.) with 1 mg/kg b. wt. lannate for one day, group J (orange juice group) orally administered a dose of 0.1 ml/10 g b. wt. of orange juice for 48 h, group J+L received the orange juice prior to lannate, group J with L received lannate in continuous with the orange juice and group L+J received lannate prior to the orange juice. Tested parameters were DNA fragmentation, micronucleus, histopathology examination and biochemical analysis.&#x0D; Results: it was found that, the intake of lannate caused high DNA fragmentation and significant increase (P&lt;0.001) in the number of micronucleated polychromatic erythrocytes in the bone marrow. Furthermore, lannate exhibited some pathological changes in the liver tissues as well as a significant (P&lt;0.001) decrease in the total antioxidative capacity (TAC) and a significant increase in the total oxidative capacity (TOC). On the other hand, orange juice administration of all treatments (pre-treatment, continuous and post-treatment) gave some amelioration against liver damage induced by lannate. While the best results were evidenced in the continuous treatment group where the juice could attenuate liver DNA fragmentation and significantly decreased (P&lt;0.001) the number of micronucleated polychromatic erythrocytes. In addition, it improved the induced degenerative histopathological changes as well as ameliorated the changes occurred in TAC and TOC significantly (P&lt;0.001).&#x0D; Conclusion: the antigenotoxic impact of orange juice against lannate was therapeutic and hence can counteract the poisonous effect of the pesticide in people who exposed to it.

Modulatory Effect of Rutin on the Antitumor Activity and Genotoxicity of Cisplatin in Tumor-Bearing Mice

Purpose: Cisplatin is a cancer chemotherapeutic drug that has been extensively used in the treatment of a variety of cancers. However, the full usage of cisplatin is limited due to its treatment associated development of multiple side effects in the host. In the present study, the modulatory effect of rutin, a type of flavonoid, on the cisplatin mediated antitumor activity and allied genotoxicity in ascites Dalton’s lymphoma (DL)-bearing mice were investigated. Methods: The antitumor activity was determined by calculating the percent increase in the life span of mice, cell viability and scanning electron microscopy (SEM) of DL cells. Further, the modulatory effect of rutin on the cisplatin-induced genotoxic effects in the same DL-bearing mice was assessed by the analysis of micronuclei, chromosomal aberration and sperm abnormality. Results: The combination treatment of mice with rutin and cisplatin showed a considerable increase in the life span of the DL-bearing mice depicting better antitumor efficacy. SEM of these DL cells showed severe membrane deformities in DL cells such as fusion of cell membrane, membrane blebbing, cell shrinkage, membrane folding and loss in microvilli from the tumor cell surface which may lead to cell death. Cisplatin alone treatment caused an increase in the frequency of chromosomal aberrations, micronuclei and sperms abnormality. However, the combination treatment of DL-bearing mice with rutin and cisplatin comparatively reduced these genotoxic effects. Conclusion: The overall findings suggest that rutin enhances the cisplatin-mediated antitumor activity and cytotoxicity against DL cells and at the same time diminishes the genotoxic effects induced by cisplatin in the DL-bearing mice.

Induction of genotoxicity and mutagenic potential of heavy metals in Thai occupational workers

Heavy metals are widely used in many industries in Thailand and found in the environment. Occupational exposure to heavy metals is often chronic and caused by environmental contaminations, potentially leading to mutations and cancer. Although the genotoxic effects of occupational exposure to multiple heavy metals have been extensively studied, the findings regarding their genotoxicity are conflicting. In this study, we focused on investigating the genotoxic effects of certain heavy metals mixtures, including lead (Pb), copper (Cu), zinc (Zn), and tin (Sn), to which workers are exposed in the manufacturing industry. The cytokinesis-blocked micronucleus (CBMN) assay in peripheral blood lymphocytes was performed, and DNA damage was assessed by measuring tumour-associated protein levels and 8-hydroxy-2′-deoxyguanosine (8-OHdG) generated by oxidative stress that causes cytotoxicity. The occupational exposure group included 110 workers exposed to heavy metal mixtures and 105 matched control subjects. We found statistically significant differences in the blood Pb, Sn, and Cu levels between the exposed workers and the control subjects (p < 0.001). Analysis of micronuclei (MN) in peripheral blood lymphocytes revealed a significantly increased frequency of MN in exposed workers compared with that in control subjects (p<0.05). Non-smoking exposed workers were selected for 8-OHdG formation and mutant p53 tests, and significant differences in the mean plasma 8-OHdG concentration (p < 0.001) were found between the occupational exposure and the control group, but no differences were found in the levels of mutant p53. Thus, chronic exposure to different heavy metals causes genotoxic effects in humans. Furthermore, the CBMN assay and 8-OHdG formation can be used as surrogate biomarkers to identify and monitor groups with higher carcinogenic risk in the early stages of toxicity. In summary, our results indicate that mixtures of heavy metals (Pb, Sn, and Cu) in manufacturing industries pose an elevated health risk due to DNA damage.

Affinin and hexahydroaffinin: Chemistry and toxicological profile.

The present work aimed to determine the safety parameters of two new alkamides, affinin and hexahydroaffinin, with antinociceptive activity. To predict the preliminary acute toxicity, we used the acute and subchronic toxicity (50 mg/kg, orally [po]) in Swiss Webster mice. Genotoxicity assayed via analysis of cell micronuclei of the femoral bone marrow in mice; at the same time, metabolic parameters determined from peripheral blood samples. Furthermore, to discard the neuropharmacological effects, we assessed the ambulatory activity in mice to determine the possible effects in the central nervous system. Finally, we used capsaicin as a positive control of alkamides. According to our results, hexahydroaffinin (LD50 ≥ 5,000 mg/kg, po) is significantly less noxious than affinin (LD50 = 1,442.2 mg/kg, po) or capsaicin (LD50 = 489.9 mg/kg, po). In subchronic administration, we did not observe any changes in hematological or biochemical parameters in any compound analyzed from peripheral blood samples. Finally, the data from the genotoxicity assay showed micronuclei formation in 28%, 5%, and 3% of mice in the capsaicin, affinin, and hexahydroaffinin groups, respectively. With the results obtained in the present investigation, we suggest that affinin and hexahydroaffinin are not only useful candidates for possible new drugs but also safe compounds.

Induction of micronuclei, nuclear anomalies, and dimensional changes in erythrocytes of the rare minnow (Gobiocypris rarus) by lanthanum.

The genotoxicity and cytotoxicity of lanthanum (La(III)) were studied in fish micronucleus analysis in erythrocytes of the rare minnow (Gobiocypris rarus). Fish were exposed to 0.04, 08, 0.16, 0.32, and 0.80 mg L-1 of La concentration for 21 days. Several important morphological alterations of the nucleus were noted, such as the ratio of micronucleated erythrocyte, and total ratio of erythrocytes with nuclear anomalies, blebs, notches, and so on. The total ratio of nuclear anomalies was significantly higher (P < 0.05) in G. rarus exposed to La(III) (except for 0.04 mg L-1) compared with the control. Hypsometric analysis indicated significant dose-dependent changes in erythrocyte and nucleus dimensions (P < 0.05). Various abnormal morphological forms of erythrocytes were also observed. These results showed that La(III) was cytotoxic to erythrocytes of the rare minnow.

Assessment of the mutagenicity of the technical product&#x0D; of N-(1-ethylpropyl)-2,6-dinitro -3,4-xylidinen

Introduction. Evaluation of genotoxicity of the pesticide technical products is one of the mandatory requirements for their toxicological and hygienic assessment. The data about mutagenic property is ambiguous for some pesticides. This may be due to the use of various active ingredients of technical products of the pesticide for testing, as they may have different profiles of relevant impurities, some of which may be potentially genotoxic. Material and methods. A technical product of N-(1-ethylpropyl)-2,6-dinitro-3,4-xylidine was tested using the bacterial reverse mutation method with Salmonella typhimurium (Ames test) and the in vivo mammalian micronucleus analysis in mouse bone marrow erythrocytes. Results. Statistically significant dose-dependent mutagenic effects of the technical product of N-(1-ethylpropyl)-2,6-dinitro-3,4-xylidine were revealed for TA97 (+S9 / -S9); TA100 (+S9 / -S9); TA102 (+S9 / -S9) and TA98 (+S9 / -S9) strains. In all cases, the fold increase of the revertant numbers mediated by the tested substance compared with the concurrent negative control was &gt; 2 except TA98 in the presence of S9. In the micronucleus test, the technical product did not induce a statistically significant increase in the frequency of the micronucleated polychromatophilic erythrocytes in CD-1 mouse bone marrow up to 2000 mg/kg bw. Conclusion. The data suggest all technical products of pesticides entering the market should be tested for the potential genotoxicity. In such a case it is necessary to use at least two methods on different test systems for obtaining reliable results.

Assessment of the mutagenicity of the technical product&#x0D; of N-(1-ethylpropyl)-2,6-dinitro -3,4-xylidinen

Introduction. Evaluation of genotoxicity of the pesticide technical products is one of the mandatory requirements for their toxicological and hygienic assessment. The data about mutagenic property is ambiguous for some pesticides. This may be due to the use of various active ingredients of technical products of the pesticide for testing, as they may have different profiles of relevant impurities, some of which may be potentially genotoxic. Material and methods. A technical product of N-(1-ethylpropyl)-2,6-dinitro-3,4-xylidine was tested using the bacterial reverse mutation method with Salmonella typhimurium (Ames test) and the in vivo mammalian micronucleus analysis in mouse bone marrow erythrocytes. Results. Statistically significant dose-dependent mutagenic effects of the technical product of N-(1-ethylpropyl)-2,6-dinitro-3,4-xylidine were revealed for TA97 (+S9 / -S9); TA100 (+S9 / -S9); TA102 (+S9 / -S9) and TA98 (+S9 / -S9) strains. In all cases, the fold increase of the revertant numbers mediated by the tested substance compared with the concurrent negative control was &gt; 2 except TA98 in the presence of S9. In the micronucleus test, the technical product did not induce a statistically significant increase in the frequency of the micronucleated polychromatophilic erythrocytes in CD-1 mouse bone marrow up to 2000 mg/kg bw. Conclusion. The data suggest all technical products of pesticides entering the market should be tested for the potential genotoxicity. In such a case it is necessary to use at least two methods on different test systems for obtaining reliable results.

Asetamipridin Fare Kemik İliği Hücrelerinde KA (Kromozomal Aberasyon) ve MN (Mikronükleus) Test Yöntemleri ile Genotoksik Etkisinin Araştırılması

In this study, we aimed to determine acetamipridine’s (ACE) genotoxic effect in mus musculus var. albinos bone marrow cells by chromosomal aberration (CA) and micronucleus (MN) analysis. Mice were divided into four groups. Group 1 determined as negative control (NC), group 2, 3 and 4 were determined as 5 mg/kg ACE, 10 mg/kg ACE, and 15 mg/kg ACE groups respectively. ACE was given orally for 14 days. CA, mitotic index (MI) and MN frequencies were determined in femoral cells. As a result, no genotoxic effects were observed in groups treated with 5-10 mg/kg ACE compared to negative control. CA rates of 15 mg/kg ACE group was determined to be high (P<0.001). In addition, MI ratio in the 15 mg/kg ACE group was lower than the control group. When the ratios of the polychromatic erythrocyte with micronucleus were examined, no significant difference was found between the 5 mg/kg and 10 mg/kg ACE groups and control group. However, a statistically significant increase in MNPCE rates was observed in the 15 mg/kg ACE group compared to control ones (P<0.001). It was concluded that ACE at 15 mg/kg dose was genotoxic-cytotoxic.

SFPQ is involved in regulating arsenic-induced oxidative stress by interacting with the miRNA-induced silencing complexes

Arsenic exposure contributed to the development of human diseases. Arsenic exerted multiple organ toxicities mainly by triggering oxidative stress. However, the signaling pathway underlying oxidative stress is unclear. We previously found that the expression of SFPQ, a splicing factor, was positively associated with urinary arsenic concentration in an arsenic-exposed population, suggesting an oxidative stress regulatory role for SFPQ. To test this hypothesis, we established cell models of oxidative stress in human hepatocyte cells (L02) treated with NaAsO2. Reactive oxygen species (ROS) synthesis displayed a time- and dose-dependent increase with NaAsO2 treatment. SFPQ suppression resulted in a 36%–53% decrease in ROS generation, leading to enhanced cellular damage determined by 8-OHdG, comet tail moment, and micronucleus analysis. Particularly, SFPQ deficiency attenuated expression of the oxidase genes DUOX1, DUOX2, NCF2, and NOX2. A fluorescent-based RNA electrophoretic mobility shift assay (FREMSA) and dual-luciferase reporter system revealed that miR-92b-5p targeted DUOX2 mRNA degradation. An RNA immunoprecipitation assay showed an interaction between SFPQ and miR-92b-5p of the miRNA-induced silencing complex (miRISC). Notably, NaAsO2 treatment diminished the interaction between SFPQ and miR92b-5p, accompanied by decreased binding between miR-92b-5p and 3′-UTR of DUOX2. However, SFPQ deficiency suppressed the dissociation of miR-92b-5p from 3′-UTR of DUOX2, indicating that miR-92b-5p regulated the SFPQ-dependent DUOX2 expression. Taken together, we reveal that SFPQ responds to arsenic-induced oxidative stress by interacting with the miRISC. These findings offer new insight into the potential role of SFPQ in regulating cellular stress response.

X chromosome aneuploidy and micronuclei in fertile mares

Abnormalities of chromosomes are an important and well documented cause of disorders of sexual development, fertility problems and congenital anomalies in mammals. Detection of low-level 63,X/64,XX mosaicism during routine cytogenetic evaluation is a challenge because its clinical significance is not yet fully clear. This study describes the prevalence and levels of 63,X mosaicism for a cohort of fertile mares and compares the results with eight problem mares for which no clinical cause of sub-fertility was found. The study design allowed for the analysis of micronuclei which are biomarkers of genomic instability and can disturb cell divisions, drive cancer development or cause congenital diseases.Although 27% of the fertile mares were identified to be 63,X mosaics, the results showed that the rates of abnormal cells were very low (1–3%). Levels of abnormal cells in problem mares with 63,X mosaicism were similar or higher. The average rate of micronuclei in the blood of the fertile mares was ∼1%, well below the baseline (5%) which was proposed for peripheral blood of normal healthy humans. We found weak to modest, but not significant, correlations between the age of fertile mares and 63,X cells (Kendall’s tau b = 0.2905; p > 0.05) as well as the rate of micronuclei (Kendall’s tau b = 0.1896; p > 0.05). Likewise, the correlation between presence of a 63,X cell line and micronuclei rate was not significant (Kendall’s tau b = 0.3201; p > 0.05). The presence of 63,X cells in rates greater than 3% may indeed indicate a higher risk for sub-fertility and eventually for associated health problems in such mares. Detection and elimination of mares with high level of X aneuploidies from breeding may have a positive effect on the fertility within the general horse population. This data may support the evaluation of problem mares with mosaic karyotypes involving the X chromosome.

Monitoring human genotoxicity risk associated to urban and industrial Buenos Aires air pollution exposure.

The quality of life in large megacities is directly affected by its air quality. In urban environments, suspended particles from anthropogenic origin is one of the main air contaminants identified as highly genotoxic, mutagenic, or carcinogenic. Atmospheric monitoring is therefore imperative, and bioassays to detect the effects of genotoxic agents give usually excellent results. Analysis of micronucleus (MN) in exfoliated oral mucosa cells is a sensitive non-invasive method for monitoring genetic damage in human populations. The first aim of this study was to analyze and characterize levels of volatile organic compounds (VOCs), particulate matter (PM), and polycyclic aromatic hydrocarbons (PAHs) in two areas from Buenos Aires: La Plata city, an urban (U) area and Ensenada, an industrial (I) area. Secondly, we evaluated the possible health risk of its inhabitants through a simple genotoxic assay on exfoliated oral mucosa cells. Whole blood cell count and nuclear abnormalities frequencies were evaluated in the exfoliated oral mucosa cells from urban and industrial inhabitants. Smoking habit represented a significant factor increasing MN percentage while, age did not increase the production of any of the nuclear aberrations assayed (micronuclei, binucleated, karyorrhexis) when the inhabitants from the urban and the industrial areas were compared. In addition, changes in MN and binucleated cell percentages in males and females were found to be area-dependent. We suggest that regardless PM concentration, PM-specific characteristics (size, shape, chemical elements, etc.) and VOCs levels could be responsible for the different harmful genotoxic effects seen in the two areas. Although this is a preliminary study, our results allowed to recognize that individuals living in both the urban and the industrial areas could be considered susceptible groups and should periodically undergo biological monitoring and appropriate care.

Occurrence of micronuclei in exfoliated buccal mucosal cells in mobile phone users: A case-control study.

The use of mobile phones has increased enormously all over the world especially among young people. This technology is based upon electromagnetic radiation in the microwave frequency range [radiofrequency (RF) waves and microwaves]. The radiation frequency and modulation standards vary in the range of 300-2100 MHz, depending on the region in the world. To detect the presence of micronuclei in exfoliated buccal mucosal cells of mobile phone users as well as to carry out a quantitative analysis of micronuclei in exfoliated buccal mucosal cells of mobile phone users. A cross-sectional study was carried out in 100 individuals, out of which 50 were included under the test group and 50 under the control group. Buccal mucosal smears were obtained from each subject. Staining was done using papanicuolau (PAP) stain and the slides were examined for the presence of micronuclei. The mean duration of mobile phone usage in years was 5.32 years for the exposed and 2.42 years for the control. Mean duration of mobile phone usage per day in the test group was 94.8 min and 12.4 min in the control group. The frequency of micronucleated cells (MNC) in test and control groups ranged from 0 to 16 and 0 to 2 respectively. The data obtained were statistically analyzed using Student t-test and significant results were obtained at 0.0001 level. Our study concluded that there is an increased frequency of micronuclei in mobile phone users which is related to carcinogenesis.

The use of a centrifuge-free RABiT-II system for high-throughput micronucleus analysis

ABSTRACTThe cytokinesis-block micronucleus (CBMN) assay is considered to be the most suitable biodosimetry method for automation. Previously, we automated this assay on a commercial robotic biotech high-throughput system (RABiT-II) adopting both a traditional and an accelerated micronucleus protocol, using centrifugation steps for both lymphocyte harvesting and washing, after whole blood culturing. Here we describe further development of our accelerated CBMN assay protocol for use on high-throughput/high content screening (HTS/HCS) robotic systems without a centrifuge. This opens the way for implementation of the CBMN assay on a wider range of commercial automated HTS/HCS systems and thus increases the potential capacity for dose estimates following a mass-casualty radiological event.