Chromosomal Damage Research Articles

Eco-Friendly Engineered Nanomaterials Coupled with Filtering Fine-Mesh Net as a Promising Tool to Remediate Contaminated Freshwater Sludges: An Ecotoxicity Investigation.

The use of eco-friendly engineered nanomaterials represents a recent solution for an effective and safe treatment of contaminated dredging sludge. In this study, an eco-designed engineered material based on cross-linked nanocellulose (CNS) was applied for the first time to decontaminate a real matrix from heavy metals (namely Zn, Ni, Cu, and Fe) and other undesired elements (mainly Ba and As) in a lab-scale study, with the aim to design a safe solution for the remediation of contaminated matrices. Contaminated freshwater sludge was treated with CNS coupled with a filtering fine-mesh net, and the obtained waters were tested for acute and sublethal toxicity. In order to check the safety of the proposed treatment system, toxicity tests were conducted by exposing the bacterium Aliivibrio fischeri and the crustacean Heterocypris incongruens, while subtoxicity biomarkers such as lysosomal membrane stability, genetic, and chromosomal damage assessment were performed on the freshwater bivalve Dreissena polymorpha. Dredging sludge was found to be genotoxic, and such genotoxicity was mitigated by the combined use of CNS and a filtering fine-mesh net. Chemical analyses confirmed the results by highlighting the abetment of target contaminants, indicating the present model as a promising tool in freshwater sludge nanoremediation.

Dose-Dependent Transmissibility of Chromosome Aberrations in Human Lymphocytes at First Mitosis. II. Biological Effectiveness of Heavy Charged Particles Versus Gamma Rays.

Chromosome aberrations (CAs) are large scale structural rearrangements to the genome that have been used as a proxy endpoint of mutagenic and carcinogenic potential. And yet, many types of CAs are incapable of causing either of these effects simply because they are lethal. Using 24-color multi-fluor combinatorial painting (mFISH), we examined CAs in normal human lymphocytes exposed to graded doses of 1 GeV/nucleon accelerated 56Fe ions and 662 keV 137Cs gamma rays. As expected, the high-linear energy transfer (LET) heavy ions were considerably more potent per unit dose at producing total yields of CAs compared to low-LET gamma rays. As also anticipated, the frequency distribution of aberrations per cell exposed to 56Fe ions was significantly overdispersed compared to the Poisson distribution, containing excess numbers of cells devoid of aberrations. We used the zero-inflated negative binomial (ZINB) distribution to model these data. Based on objective cytogenetic criteria that are subject to caveats we discuss, each cell was individually evaluated in terms of likely survival (i.e., its ability to transmit to daughter cell progeny). For 56Fe ion irradiations, the frequency of surviving cells harboring complex aberrations represented a significant portion of aberration-bearing cells, while for gamma irradiation no survivable cells containing complex aberrations were observed. When the dose responses for the two radiation types were compared, and the analysis was limited to surviving cells that contained aberrations, we were surprised to find the high-LET 56Fe ions only marginally more potent than the low-LET gamma rays for doses less than 1 Gy. In fact, based on dose-response modeling, they were predicted to be less effective than gamma rays at somewhat higher doses. The major implication of these findings is that measures of relative biological effectiveness that fail to account for coincident lethality will tend to overstate the impact of transmissible chromosomal damage from high-LET particle exposure.

Safety assessment of a solid lipid curcumin particle preparation: In vitro and in vivo genotoxicity studies.

Curcumin, one of the three principal curcuminoids found within turmeric rhizomes, has long been associated with numerous physiologically beneficial effects; however, its efficacy is limited by its inherently low bioavailability. Several novel formulations of curcumin extracts have been prepared in recent years to increase the systemic availability of curcumin; Longvida®, a solid lipid curcumin particle preparation, is one such formulation that has shown enhanced bioavailability compared with standard curcuminoid extracts. As part of a safety assessment of Longvida® for use as a food ingredient, a bacterial reverse mutation test (OECD TG 471) and mammalian cell erythrocyte micronucleus test (OECD TG 474) were conducted to assess its genotoxic potential. In the bacterial reverse mutation test, Longvida® did not induce base-pair or frame-shift mutations at the histidine locus in the genome of Salmonella typhimurium strains TA98, TA100, TA102, TA1535, and TA1537, in the presence or absence of exogenous metabolic activation. Additionally, two gavage doses (24 h apart) of Longvida® to Swiss albino mice at 500, 1000, or 2000-mg/kg body weight/day did not cause structural or numerical chromosomal damage in somatic cells in the mammalian erythrocyte micronucleus test. It was therefore concluded that Longvida® is non-genotoxic.

Comet assay to evaluate chromosomal changes in chickens (Gallus gallus domesticus) contaminated by lead in a city in Bahia.

Chicken (Gallus gallus domesticus) is one of the primary sources of animal protein for the Brazilian population. Thus, the safety of this food is highly relevant. This study was based on the evidence of severe contamination of these animals by metals such as lead in Santo Amaro, Bahia. This exploratory study aimed to evaluate associations between lead levels in blood of chicken exposed to a contaminated area with the occurrence of chromosomal alterations, evidencing genotoxic effects. Serum lead analysis was performed by GF-AAS after dilution with a matrix modifier solution (Triton X-100 0.2% v/v and HNO3 0.1% v/v), while chromosomal damage was evaluated using the comet assay. The results showed genotoxic effects (positive comet assay) only for the specimen sample with higher serum lead concentrations (33.9 µg dL-1), suggesting the occurrence of toxic effects at this level of exposure. This work evaluated a relationship between the reduction of serum lead levels in chicken and increased distance from the primary polluting source - a lead processing plant (COBRAC). It also showed that lead is bioavailable in this territory, contaminating chicken and causing genotoxic effects in these animals, further expanding the concern with the local biota and the health of the residents of Santo Amaro.

Genotoxicity and cytotoxicity effects of x-rays on the oral mucosa epithelium at different fields of view: A cone beam computed tomography technique.

Cone beam computed tomography (CBCT) is considered a common examination for dentistry problems. Cellular biology can be affected by exposure to ionizing radiations procedures. In this study, we aimed to assess the genotoxicity and cytotoxicity effects of CBCT dental examinations at two different fields of view (FOVs) in exfoliated buccal epithelial cells. Sixty healthy adults participated in the current study. They were divided into two identical groups; CBCT with FOV of 6*6 cm2 and 8*11 cm2. Exfoliated oral mucosa cells were prepared immediately before and after 10-12 days of CBCT exposure. The cytological smears were stained with the Papanicolaou technique. The amounts of micronuclei and other cytotoxicity cellular changes (Pyknosis, Karyolysis, and Karyorrhexis) were evaluated. The variables of the parameters before and after CBCT examination in the two investigated FOVs were performed using Wilcoxon test and paired-samples t-test in SPSS software. The micronuclei and other cytotoxic changes parameters before and after CBCT exposure for both FOVs (6*6 and 8*11 cm2) increased significantly (p<0.001). Furthermore, a significant difference (p<0.05) was observed between the investigated parameters at the two FOVs. Notably, the FOV of 8*11 cm2 had more side effects than that of 6*6 cm2. There were no statistically significant among males and females for both FOVs. CBCT examinations of dental disorders would increase the risks of inducing genetic damage. The cytotoxicity and chromosomal damage were considered in males and females in both investigated FOVs (6*6 and 8*11 cm2). In this regard, the use of CBCT must be following the ALARA principle.

Effect and interaction of TNKS genetic polymorphisms and environmental factors on telomere damage in COEs-exposure workers

Coke oven emissions (COEs) contain many carcinogenic polycyclic aromatic hydrocarbons (PAHs). Telomere damage is an early biological marker reflecting long-term COEs-exposure. Whereas, whether the genetic variations of telomere-regulated gene TNKS have an effect on the COEs-induced telomere damage is unknown. So we detected the environmental exposure levels, relative telomere length (RTL), and TNKS genetic polymorphisms among 544 COEs-exposure workers and 238 healthy participants. We found that the RTL of the wild homozygous GG genotype in rs1055328 locus was statistically shorter compared with the CG+CC genotype for the healthy participants using covariance analysis(P = 0.008). In the Generalized linear model (GLM) analysis, TNKS rs1055328 GG could accelerate telomere shortening (P = 0.011); and the interaction between TNKS rs1055328 GG and COEs-exposure had an effect on RTL (P = 0.002). In conclusion, this study was the first to discover the role of TNKS rs1055328 locus in COEs-induced telomere damage, and proved that chromosomal damage was a combined consequence of environmental and genetic factors.

Visualizing the Nucleome Using the CRISPR–Cas9 System: From in vitro to in vivo

One of the latest methods in modern molecular biology is labeling genomic loci in living cells using fluorescently labeled Cas protein. The NIH Foundation has made the mapping of the 4D nucleome (the three-dimensional nucleome on a timescale) a priority in the studies aimed to improve our understanding of chromatin organization. Fluorescent methods based on CRISPR-Cas are a significant step forward in visualization of genomic loci in living cells. This approach can be used for studying epigenetics, cell cycle, cellular response to external stimuli, rearrangements during malignant cell transformation, such as chromosomal translocations or damage, as well as for genome editing. In this review, we focused on the application of CRISPR-Cas fluorescence technologies as components of multimodal imaging methods for in vivo mapping of chromosomal loci, in particular, attribution of fluorescence signal to morphological and anatomical structures in a living organism. The review discusses the approaches to the highly sensitive, high-precision labeling of CRISPR-Cas components, delivery of genetically engineered constructs into cells and tissues, and promising methods for molecular imaging.

Mutation in Ontogene and Emergence of Secondary Chromosome Damages in Drosophila Germline Cells

Mutation in Ontogene and Emergence of Secondary Chromosome Damages in Drosophila Germline Cells

Assessment of Cytogenetic Damage in Flexographic Workers: Micronucleus Assay in Exfoliated Buccal Epithelial Cells.

Literature review revealed that chemicals used in the printing industry show an association between genotoxicity and occupational exposure. Flexography is one type of printing technique recently becoming popular because of its fast, cost-efficient, and high-quality label printing. The micronucleus (MN) is considered to be a reliable marker for genotoxic damage, and it has a close association with cancer incidences by determining the presence and the extent of the chromosomal damage. Because there are no studies on flexographic workers (FWs), this study was intended to analyze and evaluate the effect of occupational exposure on the MN frequency of buccal epithelial cells. The study comprised 100 FWs and 100 age-matched healthy controls with and without smoking habits. Buccal epithelial cells were collected from all subjects by using a cytobrush, followed by staining with Feulgen fast green. The MN frequency was recorded for each individual using the Tolbert et al. criteria. Data was statistically analyzed by using one-way analysis of variance and the posthoc test. FWs with smoking habits showed a significant increase in MN frequency (1.86 ± 1.77) than workers without the habit (1.02 ± 1.08) and controls (with the habit 1.26 ± 1.33 and without the habit 0.62 ± 0.92). However, there was no significant increase of MN in FWs without the habit when compared with controls. This study observed the cytogenetic damage in FWs and concludes that these workers are at greater risk for genotoxicity, and the MN assay can serve as a useful biomarker.

Tatlandırıcı Olan Xylitol'ün In Vitro Genotoksik Etkilerinin İncelenmesi

Xylitol (XYL) is a sweetener used as a food additive in the food industry. In the present study, four different genotoxicity assays (chromosomal aberration=CA, sister chromatid exchange=SCE, cytokinesis-block micronucleus cytome=CBMN-Cyt, and comet assays) were conducted to assess the potential genotoxicity of XYL in human lymphocytes. Four concentrations (125, 250, 500, and 1000 μg mL-1) of XYL were applied to lymphocytes obtained from three healthy young donors. The frequency of CA was not significantly affected by 24-h administration of XYL (except 1000 μg mL-1 for the number of CAs). 48 h treatment of XYL increased the frequency of CAs and abnormal cells. However, this increase was significant at only two highest concentrations. XYL significantly increased SCE/cell rate at the two highest concentrations at both treatment times (24 and 48h). Similarly, the frequency of MN, Nuclear buds (NBUDs), and Nucleoplasmic bridges (NPBs) significantly increased by XYL only at the high concentrations. It raised the comet parameters at the two highest concentrations. These observations showed that XYL, only at high concentrations, may have a genotoxic effect on human lymphocytes in vitro. For this reason, it can be concluded that its use at low concentrations may not cause DNA or chromosomal damage.

Integrated genotoxicity of secondary and tertiary treatment effluents in North China

Genotoxic effects on aquatic organisms caused by wastewater discharging have raised extensive concerns. However, the efficiency of various wastewater treatment processes to reduce effluent genotoxicity was not well known. Genotoxic effects of effluents from four secondary wastewater treatment plants (SWTPs) and a tertiary wastewater treatment plant (TTP) in north China on Chinese rare minnows (Gobiocypris rarus) were evaluated and the toxicity reduction efficiency of various treatment techniques was compared. SWTPs and TTP final effluents disturbed the antioxidant system and lipid peroxidation, with malondialdehyde (MDA) contents in the fish livers and gills increasing to 1.4–2.4 folds and 1.6–3.1 folds of control, respectively. Significant increases in erythrocytes micronucleus (MN) frequency were induced by effluent, and liver DNA damage caused by final SWTPs effluent was 29–54 % lower than TTP effluent. Further, DNA repair gene atm and growth arrest gene gadd45a were remarkably upregulated by SWTP and TTP final effluents to 1.8–12 folds and 4.1–15 folds, respectively, being consistent with the chromosomal aberration and DNA damage in liver tissue. Integrated biomarker response (IBR) of the tertiary effluent was 49 %–69 % lower than the secondary effluents. However, the final ozone disinfection at TTP caused an increase in the DNA damage, suggesting the generation of genotoxic by-products. UV disinfection at secondary treatment removed part of genotoxicity, with a reduction in IBR of 0 %–47 %. The total semi-volatile organic compounds (SVOCs) detected in the final effluent contained 5 %–56 % potential genotoxic substances, removal of which was 9 %–51 % lower than non-genotoxic compounds. Microfiltration and reverse osmosis process exhibited good performance in removing both the integrated genotoxicity and the potential genotoxic SVOCs. Our finding shows that TTP is superior than SWTP for wastewater treatment due to higher genotoxicity removal, but ozone disinfection needs improvement by optimizing performance parameters or adding post-treatment processes, to achieve better protection for aquatic organisms against genotoxic contaminants.

Antimitotic and Antiproliferative Action of &lt;i&gt;Ficus septica&lt;/i&gt; Burm. F. Stem Bark Ethanolic Extract

Ficus septica is a widely documented ethnomedicinal plant that locals have used in varied applications due to its antibacterial, antioxidant, antimutagenic, renoprotective, and other biological activities. The present study investigates the antimitotic and antiproliferative actions of F. septica stem bark crude ethanolic extract using onion (Allium cepa) root tip assay and yeast (Saccharomyces cerevisiae) proliferation assay. A. cepa assay showed that the F. septica stem bark crude ethanolic extract can block mitosis in onion root cells by causing spindle and chromosome damage. The extract is genotoxic based on the increasing frequency of chromosomal aberrations at higher concentrations. Mitotic anomalies observed are sticky chromosomes, vagrant chromosomes, laggard, pole deviation, and polyploidy. It also showed that the extract decreased the cell viability of the yeast cells in a concentration-dependent manner. This study revealed that F. septica stem bark crude ethanolic extract has antimitotic and antiproliferative properties in A. cepa root tips and yeasts. Further study could be performed focusing on identifying and isolating antimitotic, and antiproliferative components of F. septica stem bark and conducting biological screening using other models.

Chronic dust bronchitis: composition of the sputum bacterial microbiome and its association with chromosome damage in blood lymphocytes

BACKGROUND: Recent studies show that the bacterial microbiome of the respiratory tract can influence the development of a number of diseases of the human respiratory system. Changes in the composition of the microbiome in patients are associated with dysbiosis, and in addition, many bacteria have a genotoxic potential and can directly or indirectly damage the genome in the cells of the host organism.&#x0D; AIM: The aim of the study was to analyze the composition of the sputum microbiome and its relationship with chromosome damage in the blood leukocytes of patients with chronic dust bronchitis (CDB).&#x0D; MATERIALS AND METHODS: The taxonomic composition of the sputum microbiome of 22 patients with CKD and 22 sputum donors from the control group was studied using next-generation sequencing (NGS) technology of 16S rRNA of bacterial genes. At the same time, the basic frequencies of chromosomal aberrations and micronuclei were determined in blood leukocytes.&#x0D; RESULTS: The sputum microbiome of chronic dust bronchitis patients had a significant reduction in alpha and beta diversity parameters compared to healthy study participants. In addition, an increase in the relative abundance of the genus Streptococcus (29.97 3.03 vs. 18.78 2.47; p = 0.003) was found in the sputum of CP patients compared with the control. Thus, the results of metagenome sequencing indicate a common dysbiotic process with a predominance of one dominant genus of bacteria in this pulmonary pathology. The results of cytogenetic analysis of blood leukocytes showed a significant increase in the proportion of aberrant metaphases in CKD patients compared with healthy donors (3.41% vs. 1.84%; p 0.01) and the absence of significant differences in frequency leukocytes with micronuclei between the compared groups (1.28% vs. 1.11%). Correlation analysis revealed the presence of significant direct relationships between the frequency of aberrant metaphases and the percentage of representatives of the genera Bacteroides in the sputum of patients with chronic dust bronchitis (r = 0.471; p = 0.031); Lachnoanaerobaculum (r = 0.446; p = 0.043) and Alloprevotella (r = 0.444; p = 0.044). Further studies should be devoted to the search for possible mechanisms of influence of these bacteria on clastogenic effects in the cells of the host organism.

HslO ameliorates arrested ΔrecA polA cell growth and reduces DNA damage and oxidative stress responses

Chromosome damage combined with defective recombinase activity has been widely considered to render cells inviable, owing to deficient double-strand break repair. However, temperature-sensitive recAts polA cells grow well upon induction of DNA damage and supplementation with catalase at restrictive temperatures. These treatments reduce intracellular reactive oxygen species (ROS) levels, which suggests that recAts polA cells are susceptible to ROS, but not chronic chromosome damage. Therefore, we investigated whether polA cells can tolerate a complete lack of recombinase function. We introduced a ΔrecA allele in polA cells in the presence or absence of the hslO-encoding redox molecular chaperon Hsp33 expression plasmid. Induction of the hslO gene with IPTG resulted in increased cell viability in ΔrecA polA cells with the hslO expression plasmid. ΔrecA polA cells in the absence of the hslO expression plasmid showed rich medium sensitivity with increasing ROS levels. Adding catalase to the culture medium considerably rescued growth arrest and decreased ROS. These results suggest that hslO expression manages oxidative stress to an acceptable level in cells with oxidative damage and rescues cell growth. Overall, ROS may regulate several processes, from damage response to cell division, via ROS-sensitive cell metabolism.

ZIM, a Norbornene Derived from 4-Aminoantipyrine, Induces DNA Damage and Cell Death but in Association Reduces the Effect of Commercial Chemotherapeutics

Cancer incidence is increasing, and the drugs are not very selective. These drugs cause adverse effects, and the cells become resistant. Therefore, new drugs are needed. Here, we evaluated the effects of ZIM, a candidate for chemotherapy, and 4-AA alone and in association with commercial chemotherapeutic agents. Subsequently, the results of ZIM and 4-AA were compared. Male Swiss mice were treated with doses of 12, 24, or 48 mg/kg ZIM or 4-AA alone or in association with cisplatin (6 mg/kg), doxorubicin (16 mg/kg), and cyclophosphamide (100 mg/kg). Biometric parameters, DNA damage (comet and micronuclei), cell death, and splenic phagocytosis were evaluated. DNA docking was also performed to confirm the possible interactions of ZIM and 4-AA with DNA. 4-AA has been shown to have low genotoxic potential, increase the frequency of cell death, and activate phagocytosis. ZIM causes genomic and chromosomal damage in addition to causing cell death and activating phagocytosis. In association with chemotherapeutical agents, both 4-AA and ZIM have a chemopreventive effect and, therefore, reduce the frequency of DNA damage, cell death, and splenic phagocytosis. The association of 4-AA and ZIM with commercial chemotherapeutic agents increased the frequency of lymphocytes compared to chemotherapeutic agents alone. Molecular docking demonstrated that ZIM has more affinity for DNA than 4-AA and its precursors (1 and 2). This was confirmed by the lower interaction energy of the complex (-119.83 kcal/mol). ZIM can break the DNA molecule and, therefore, its chemotherapeutic effect can be related to DNA damage. It is considered that ZIM has chemotherapeutic potential. However, it should not be used in combination with cisplatin, doxorubicin, and cyclophosphamide as it reduces the effects of these drugs.

Telomerase and Anticancer Treatment

Current chemotherapy uses compounds of organometallic nature that act with different mechanisms of action. Many pharmacological studies are directed toward the creation of compounds with more specific and selective activity toward tumor targets, including telomerase. The design and synthesis of such compounds with specific antitelomerase activity must consider the mechanism of action of the enzyme and its structure. The discovery of a close correlation between telomerase activation, cell immortalization and oncogenesis has suggested that telomerase inhibitors could be potent therapeutic agents, capable of selectively killing cancer cells. Inhibition of telomerase is expected to lead toward shortening of telomeres to a critical length, such that replicative senescence and cell death due to irreparable chromosomal damage can result. It has been observed that cancer cells generally have shorter telomeres than the normal replicative cell population, probably because the malignant cells have undergone more divisions. Therefore, the inhibition telomeres of cancer cells after a few cycles of cell division, without the normal cells suffering harmful consequences during therapy. Telomerase is certainly an interesting target on which to continue to study molecules that inhibit its function to obtain a specificity of therapeutic intervention and a reduction of the nonspecific cytotoxicity of chemotherapy.

Connections between sister and non-sister telomeres of segregating chromatids maintain euploidy

The complete separation of sister chromatids during anaphase is a fundamental requirement for successful mitosis. Therefore, divisions with either persistent DNA-based connections or lagging chromosome fragments threaten aneuploidy if unresolved. Here, we demonstrate the existence of an anaphase mechanism in normally dividing cells in which pervasive connections between telomeres of segregating chromosomes aid in rescuing lagging chromosome fragments. We observe that in a large proportion of Drosophila melanogaster neuronal stem cell divisions, early anaphase sister and non-sister chromatids remain connected by thin telomeric DNA threads. Normally, these threads are resolved in mid-to-late anaphase via a spatial mechanism. However, we find that the presence of a nearby unrepaired DNA break recruits histones, BubR1 kinase, Polo kinase, Aurora B kinase, and BAF to the telomeric thread of the broken chromosome, stabilizing it. Stabilized connections then aid lagging chromosome rescue. These results suggest a model in which pervasive anaphase telomere-telomere connections that are normally resolved quickly can instead be stabilized to retain wayward chromosome fragments. Thus, the liability of persistent anaphase inter-chromosomal connections in normal divisions may be offset by their ability to maintain euploidy in the face of chromosome damage and genome loss.

Detection and analysis of chemical-induced chromosomal damage for public health: integrating new approach methodologies and non-animal methods.

Chromosomal damage occurs both endogenously and exogenously and is a crucial factor in the induction of carcinogenesis. Chemically induced chromosomal damage is mainly exogenous. The OECD has developed methods to detect chemicals that induce chromosomal damage so as to identify hazardous substances and limit their exposure to humans. The development and improvement of in vitro mammalian cell methods have been the focus of recent research, as these techniques have higher throughput than in vivo animal methods and are cruelty-free. In vitro mammalian cell methods are highly sensitive and widely used. Nevertheless, they have a high frequency of misleading positive test results, causing the wastage of vital raw materials and pharmaceutical agents, and necessitating additional in vivo animal tests. Therefore, the improvement of in vitro mammalian cell methods is required. Novel methodologies have been proposed and developed for robust animal-free evaluation. As they include omics and AI approaches that use big data, they may enable objective, multidirectional interpretation when applied in combination with current in vitro experimental techniques. We review the existing approaches toward improving chromosome damage detection and introduce innovative techniques that facilitate animal-free testing. The current and latest evaluation methods can support the protection of public health as well as the development of promising chemicals that enrich our lives.

Evaluation &amp; comparison of micronuclei in smokers with &amp; without diabetes

Background: Micronuclei are chromatin masses that arise from chromosomal fragments or whole chromosome that lack behind at the anaphase stage of cell division. Their presence in cells means the number of chromosomal aberrations arising during mitosis. Cigarette smoke contains over 4000 chemical carcinogens, with 200 known carcinogens that show significant genotoxic effects in human cells. Chronic high levels of glucose during Diabetes Mellitus are thought to increase oxidative stress and the formation of free radicals that in turn damage cells. Reactive oxygen species chemically attack cellular components altering metabolism, inflammatory mediators, and antioxidant defense mechanisms, overall favoring the pathogenesis of the disease and the persistence of genetic damage. Scoring of micronuclei is considered a DNA damage biomarker for chromosomal damage and instability. Aim: Considering this, we decided to evaluate & compare the frequency of micronuclei in oral epithelial cells in smokers & in diabetics. Materials & Methods: A total number of eligible 150 individuals were included in the study; 50 smokers without diabetes, 50 smokers with diabetes & 50 age and sex matched non smoker healthy individuals group as controls. Oral epithelial cells were taken from buccal smears and subjected to PAP stain. Mean micronuclei were taken from all the subjects. Results: Least number of micronuclei was found in non smoker, non diabetic group & highest numbers were found in smoker, Diabetic group. Conclusion: Micronuclei assay is non-invasive technique that offers a very simple method for obtaining information on status of the epithelial cells, particularly DNA damage, proliferative potential of basal cells and cell death.

Изучение бактериального микробиома мокроты больных раком легкого и его связи с повреждениями хромосом в лимфоцитах периферической крови

Микробиом респираторного тракта может оказывать значимое влияние на развитие ряда заболеваний дыхательной системы человека. Помимо дисбиотических изменений в составе микробиома пациентов отмечено, что многие бактерии обладают генотоксическим потенциалом и способны прямо или опосредованно повреждать геном в клетках организма хозяина. Цель исследования - изучить связь между составом микробиома мокроты и уровнем повреждений хромосом в лейкоцитах крови больных раком легкого (РЛ). Изучены таксономический состав бактериального микробиома мокроты, а также базовые частоты хромосомных аберраций (ХА) и микроядер (МЯ) в лимфоцитах крови 66 мужчин с диагнозом РЛ и у 62 здоровых доноров. Результаты секвенирования показали, что микробиом больных РЛ имеет признаки дисбиоза с достоверным увеличением содержания бактерий родов Streptococcus, Bacillus, Gemella и Haemophilus. У пациентов с РЛ выявлена прямая связь между частотой аберрантных метафаз в лимфоцитах и процентным содержанием в мокроте представителей рода Bacteroides. The microbiome of the respiratory tract can have a significant impact on the development of a number of diseases of the human respiratory system. In addition to dysbiotic changes in the composition of the microbiome of patients, it was noted that many bacteria have a genotoxic potential and are able to directly or indirectly damage the genome in the cells of the host organism. The aim of the study was to study the relationship between the composition of the sputum microbiome and the level of chromosome damage in the blood leukocytes of patients with lung cancer (LC). The taxonomic composition of the sputum bacterial microbiome, as well as the basic frequencies of chromosomal aberrations (CA) and micronuclei (MN) in blood lymphocytes of 66 men diagnosed with LC and 62 healthy donors were studied. The results of sequencing showed that the microbiome of LC patients has signs of dysbiosis with a significant increase in the content of bacteria of the genera Streptococcus, Bacillus, Gemella and Haemophilus. In patients with LC, a direct relationship was found between the frequency of aberrant metaphases in lymphocytes and the percentage of representatives of the genus Bacteroides in sputum.