Frequency Of Chromosomal Aberrations Research Articles

Background Level of Unstable Chromosome Aberrations in the Kazakhstan Population: A Human Biomonitoring Study.

Kazakhstan is known as a country with a complex radioecological situation resulting from different sources such as a natural radiation background, extensive activities of the industrial system of the former Soviet Union and a well-known testing of nuclear power weapons occurred in the Semipalatinsk Test Site (STS) area. The present study focuses on the assessment of the background of dicentric chromosomes in Kazakhstan’s population, which is the starting point in the dose assessment of irradiated people, since the baseline level of spontaneous dicentrics can vary significantly in different populations. In this context, aiming to determine the background frequency of chromosome aberrations in the population of Kazakhstan, considering the heterogeneity of natural radiation background levels of its large territory, a selection of 40 control subjects living in four cities of North, South, West and East Kazakhstan was performed. The cytogenetic study on the selected groups showed fairly low background frequency values of chromosome aberrations (0.84 ± 0.83 per 1000 cells), comparable with other data in the literature on general populations, reporting background frequency values between 0.54 and 2.99 per 1000 cells. The obtained results should be taken into account when constructing the dose–effect calibration curve used in cytogenetic biodosimetry, as a “zero” dose point, which will reduce the uncertainty in quantifying the individual absorbed dose in emergency radiological situations.

Investigation of cypermethrin toxicity in Swiss albino mice with physiological, genetic and biochemical approaches

In this study, cypermethrin toxicity was investigated using physiological, biochemical and cytogenetic parameters, and more than one organ and cell type was preferred to determine these effects. In this multifaceted study, the genotoxicity mechanism of cypermethrin was elucidated by molecular docking. In addition, comet assay technique was applied to detect and quantify DNA damage at the cell level. For this aim, body and organ weights, aspartate aminotransferase (AST), alanine aminotransferase (ALT), malondialdehyde (MDA), glutathione (GSH), blood urea nitrogen (BUN) and creatinine levels, mitotic index (MI), DNA fragmentation, frequency of micronucleus (MN) and chromosomal aberrations (CAs) were used as indicators of toxicity. Mice were divided into 4 groups. The control group was fed with tap water and the administration groups were orally exposed to 62.5, 125 and 250 mg/kg b.w cypermethrin for 28 days. Then, the mice were sacrificed and tissue samples were collected. Cypermethrin caused a decrease in body and organ weights, GSH levels and MI and an increase in AST, ALT, MDA, BUN, creatinine levels and the frequency of MN and CAs (break, ring, gap, acentric, etc.). Cypermethrin promoted MN formation in leukocyte, erythrocyte, buccal mucosa epithelial cells. CAs and MN formation promoted by cypermethrin have been associated with DNA-cypermethrin interactions. This interaction has been demonstrated by simulation with molecular docking method and experimentally by spectral measurements of DNA. As a result, all three doses of cypermethrin caused toxicity in different cell types. In other words, the effect of cypermethrin taken into the body was not limited to only one cell type or region. Therefore, cypermethrin is a pyrethroid insecticide that promotes multifaceted toxicity in non-target organisms.

P-564 Advanced paternal age is associated with higher rate of segmental chromosomal aberrations in preimplantation embryos

Abstract Study question Is there a correlation between paternal age and the frequency of chromosomal aberrations in embryos created by in vitro fertilization (IVF)? Summary answer There is an association between paternal age and segmental aberration rates in embryos derived from young oocyte providers after adjusting for age,sperm,and IVF-cycle characteristics. What is known already Paternal reproductive aging(APA) is less understood than maternal reproductive aging(AMA). Embryo aneuploidy presents one of the most important determinants of transfer cycle success. The association of AMA with increased rate of aneuploidy is well established. The systematic review and meta-analysis published by our group did not identify an association of APA with aneuploidy, based on ∼10,000 pooled embryos, however, the power to detect subchromosomal aberrations was limited by the sensitivity of the PGT-A platform used by each center. Our aim was to study the impact of APA on chromosomal aberrations in a large sample size analyzed by high resolution PGT-A. Study design, size, duration This was a retrospective cohort study performed at the CReATe Fertility Centre Genetics Laboratory, Toronto, Canada, between January 2019-December 2021. A total of 17731 blastocysts from 3506 cycles (2502 patients) were analyzed using high resolution NGS PGT-A (10Mb resolution; 30%-70% reported as mosaicism). Clinical, laboratory and demographic data were obtained for statistical analysis. Participants/materials, setting, methods Embryos were allocated into two groups by oocyte-provider age: ≤33years and ≥34years. Each group was divided into four sub-groups by paternal age: Group A 20-29(n = 484); GroupB 30-39(n = 9704); GroupC 40-49(n = 6341); GroupD≥50(n = 1202). Multiple logistic/ordinal regressions were conducted to evaluate euploidy, mosaicism and aneuploidy rates between age groups, as appropriate. Each was further sub-analyzed by type of abnormality A-single-whole-chromosome, S-segmental, C-complex (≥2 full-chr-aberrations). Segmental aberrations were divided into subgroups of S + (segmental gain), S-(segmental loss) and CS(complex segmental). Main results and the role of chance High resolution NGS PGT-A analysis of 17731 embryos showed 54.9% were euploid, 31.5% were aneuploid and 13.6% mosaic. In the oocyte provider’s age of ≤ 33 group, significant differences between paternal age group A vs. B, C and D were found in euploidy rates (68.8%, 62.5%, 61.7%, 59.0% respectively; p = 0.00559). There were no significant differences in aneuploidy rates (19.1%, 22.7%, 22.5%, 24.6% respectively; p = 0.07184) or mosaicism rates (12.1%, 14.8%, 15.8%, 16.3%; respectively, p = 0.23754). In the oocyte provider’s age of ≥ 34 group, decreasing euploidy rates and increasing aneuploidy rates were observed between all paternal age groups (p = 0.00001 and p < 0.00001,respectively), and no significant differences in mosaicism rates (14%, 12%, 10.2%, 11.6% respectively) reflecting the maternal age effect on euploidy/aneuploidy. In the oocyte provider’s age of ≤ 33 group, paternal group A (2.3%) had significantly lower segmental (S) rates compared to groups B (4.3%, p = 0.027599), C (3.3%, p = 0.039924) and D (4.6%, p = 0.018478). In addition, segmental losses (S-) were lower in group A (1.3%) compared to groups B (3.4%, p = 0.020431), C (3.1%, p = 0.043166) and D (3.7%, p = 0.016385). Limitations, reasons for caution The main limitation was the retrospective nature of this study; however, multiple regression analyses were conducted to limit potential bias by adjusting for sperm and oocyte characteristics. In addition, PGT-A analysis cannot provide information on origin of the aneuploidy and all conclusions are deduced from indirect associations to paternal age. Wider implications of the findings The results of this study provide important information to assist fertility practitioners when providing pre-conception counseling to patients, particularly for couples in which the male partner belongs to an older age group. Trial registration number na

Hypersensitivity and Induced Radioresistance in Chinese Hamster Cells Exposed to Radiations with Different LET Values.

We study the impact of radiation LET on manifestation of HRS/IRR response in Chinese hamster cells ovary cells exposed to radiations used in radiotherapy. Earlier we have investigated this response to carbon ions (455 MeV/amu) in the pristine Bragg curve plateau and behind the Bragg peak, 60Co γ-rays, and 14.5 MeV neutrons. Now we present results of cytogenetic metaphase analysis in plateau-phase CHO-K1 cells irradiated with scanning beam protons (83 MeV) at doses < 1 Gy and additional data for 14.5 MeV neutrons. Dose curves for frequency of total chromosome aberrations (CA, protons), paired fragments (protons, neutrons), aberrant cells (neutrons) had typical HRS/IRR structure: HRS region (up to 0.1 and 0.15 Gy), IRR region (0.1–0.6 Gy and 0.15–0.35 Gy) for protons and neutrons, respectively, and regular dose dependence. Taken together with previous results, the data show that LET increase shifts the HRS upper border (from 0.08–0.1 Gy for γ-rays, protons and plateau carbons to 0.12–0.15 Gy for “tail” carbons and neutrons). The IRR regions shortens (0.52–0.4 γ-rays and protons, 0.25 plateau carbons, 0.2 Gy “tail” carbons and neutrons). CA level of IRR increases by 1.5–2.5 times for carbons as compared to γ-rays and protons. Outside HRS/IRR the yield of CA also enhanced with LET increase. The results obtained for different LET radiations suggest that CHO-K1 cells with G1-like CA manifested the general feature of the HRS/IRR phenomena.

Vitamin B6 rescues insulin resistance and glucose-induced DNA damage caused by reduced activity of Drosophila PI3K.

The insulin signaling pathway controls cell growth and metabolism, thus its deregulation is associated with both cancer and diabetes. Phosphatidylinositol 3‐kinase (PI3K) contributes to the cascade of phosphorylation events occurring in the insulin pathway by activating the protein kinase B (PKB/AKT), which phosphorylates several substrates, including those involved in glucose uptake and storage. PI3K inactivating mutations are associated with insulin resistance while activating mutations are identified in human cancers. Here we show that RNAi‐induced depletion of the Drosophila PI3K catalytic subunit (Dp110) results in diabetic phenotypes such as hyperglycemia, body size reduction, and decreased glycogen content. Interestingly, we found that hyperglycemia produces chromosome aberrations (CABs) triggered by the accumulation of advanced glycation end‐products and reactive oxygen species. Rearing PI3K RNAi flies in a medium supplemented with pyridoxal 5′‐phosphate (PLP; the catalytically active form of vitamin B6) rescues DNA damage while, in contrast, treating PI3K RNAi larvae with the PLP inhibitor 4‐deoxypyridoxine strongly enhances CAB frequency. Interestingly, PLP supplementation rescues also diabetic phenotypes. Taken together, our results provide a strong link between impaired PI3K activity and genomic instability, a crucial relationship that needs to be monitored not only in diabetes due to impaired insulin signaling but also in cancer therapies based on PI3K inhibitors. In addition, our findings confirm the notion that vitamin B6 is a good natural remedy to counteract insulin resistance and its complications.

Assessment of the effects of fungicide (Thiram) on somatic cells of broad bean (Vicia faba L.)

Present study was carried out to know the impact of fungicide (Thiram) on somatic cells of broad bean (Vicia faba L.). Thiram is one of the most effective fungicide. Significant inhibition of mitotic index and increase in the frequencies of chromosome aberrations were observed. Results of the study indicate that both the plant bioassay found to be sensitive indicators for the genotoxicity assessment as the outcome of majority test system. Using plant bioassays for testing and monitoring environmental chemicals or pollution has many advantages. The mitotic index decreases due to exposure of plant extract with thiram in higher concentration as 150, 300, 550, 800 ppm for 8h and show reducing effect that is 21.00, 20.70, 18.61 and 16.77 in comparison to control that is 21.19. The higher concentrations of fungicide showed the genotoxic effects and damage the chromosomal integrity.

Toxicological Assessment of Methanolic Fruit Extract of &lt;i&gt;Zanthoxylum acanthopodium&lt;/i&gt; DC. in Swiss Albino Mice: Acute and Sub-acute Toxicity Study

Zanthoxylum acanthopodium DC. is widely used in traditional plant-based medical practices in India, with different parts of this plant used to treat a variety of ailments. Though this has been a time-tested practice, the side effects and other implications that the plant may have should not be overlooked. This study evaluated the toxicity of the methanolic fruit extract of Z. acanthopodium in Swiss albino mice by conducting acute and sub-acute toxicity tests using hematological, biochemical, ultrastructural analysis, sperm abnormality, and genotoxicity as parameters. For the acute toxicity test, mice were treated with a single dose of 5000 mg extract/kg bw of mice. While for sub-acute toxicity test, doses of 200, 500, and 1000 mg of the extract/kg bw were administered to the mice. Furthermore, a satellite group of the respective control group and the highest dose group were employed to observe the post-treatment effect that the plant may have. The acute toxicity test resulted in a significant reduction of the mean body weight gain in treated mice, but, no signs of morbidity and mortality were recorded. Sub-acute toxicity test revealed a negative effect of the plant extract on the blood and biochemical parameters. Light and electron microscopic examination of the liver and kidney showed the damaging effects of the extract on the tissues and the cellular structures. In addition, the extract induced sperm abnormalities with a significant reduction of sperm count and sperm viability, and caused an increase in the percentage of abnormally shaped sperms. The extract treatment also resulted in an increased frequency of chromosomal aberrations as well as cell death.

Genotoxic effects of electromagnetic field radiations from mobile phones

The use of wireless communication technology in mobile phones has revolutionized modern telecommunication and mobile phones have become so popular that their number exceeds the global population. Electromagnetic field radiations (EMR) are an integral part of wireless technology, which are emitted by mobile phones, mobile tower antennas, electric power stations, transmission lines, radars, microwave ovens, television sets, refrigerators, diagnostic, therapeutic, and other electronic devices. Manmade EMR sources have added to the existing burden of natural EMR human exposure arising from the Sun, cosmos, atmospheric discharges, and thunder storms. EMR including radiofrequency waves (RF) and extremely low-frequency radiation (ELF) has generated great interest as their short-term exposure causes headache, fatigue, tinnitus, concentration problems, depression, memory loss, skin irritation, sleep disorders, nausea, cardiovascular effects, chest pain, immunity, and hormonal disorders in humans, whereas long-term exposure to EMR leads to the development of cancer. The review has been written by collecting the information using various search engines including google scholar, PubMed, SciFinder, Science direct, EMF-portal, saferemr, and other websites from the internet. The main focus of this review is to delineate the mutagenic and genotoxic effects of EMR in humans and mammals. Numerous investigations revealed that exposure in the range of 0–300 GHz EMR is harmless as it did not increase micronuclei and chromosome aberrations. On the contrary, several other studies have demonstrated that exposure to EMR is genotoxic and mutagenic as it increases the frequency of micronuclei, chromosome aberrations, DNA adducts, DNA single and double strand breaks at the molecular level in vitro and in vivo. The EMR exposure induces reactive oxygen species and changes the fidelity of genes involved in signal transduction, cytoskeleton formation, and cellular metabolism.

Path Analysis : Public Health Impacts Overview in High Natural Background Radiation Area in Botteng, West Sulawesi of Indonesia

Introduction: The effect of ionizing radiation exposure in a human being is chromosome aberrations. Botteng has the highest annual radiation exposure rate in Indonesia, which is 6,15 ± 0,81 mSv/year. The people in Botteng were exposed to the low dose radiation, continuously. The purpose of this research is to describe the pathway radiation exposured to inhabitants and the cytogenetic response in the high natural background radiation area.Methods : This is a statistical research by cross-sectional. The population is 61 residents, who were chosen randomly from 9 different exposure rate areas. Path analysis model is used to determine the linearity relationship between internal and external radiation dose to the frequency of chromosomal aberrations in lymphocyte cells.Results: The results concluded that the external radiation dose rate is 5.49 mSv / year, the internal radiation dose rate is 10.34 mSv / year, the effective dose rate of lymphocyte cells is 1.92 mSv / year, and the mean of chromosome aberrations frequency is 0.00082 of approximately 14,695 metaphase cells observed. The result of the analysis showed that there was no significant correlation between the external dose and the chromosome aberrations frequency. There is a linear relationship between the internal dose and the chromosome aberrations frequency (f count = 6,634 and p-value 0,013 &lt;0,05). The internal and external radiation dose simultaneously affects the effective dose (R2 = 0.901, p-value = 0,000&gt; 0.05), The Internal and external radiation doses affect the chromosome aberrations frequency of peripheral blood lymphocytes only through effective doses (R2 = 0.093, p-value = 0.017&gt; 0.05)Conclusion: this study provide an effective recommendation for further research as an effort to improve public health in areas with high natural background radiation.

Comparative Genomic Hybridization to Microarrays in Fetuses with High-Risk Prenatal Indications: Polish Experience with 7400 Pregnancies.

The aim of this study was to determine the suitability of the comparative genomic hybridization to microarray (aCGH) technique for prenatal diagnosis, but also to assess the frequency of chromosomal aberrations that may lead to fetal malformations but are not included in the diagnostic report. We present the results of the aCGH in a cohort of 7400 prenatal cases, indicated for invasive testing due to ultrasound abnormalities, high-risk for serum screening, thickened nuchal translucency, family history of genetic abnormalities or congenital abnormalities, and advanced maternal age (AMA). The overall chromosomal aberration detection rate was 27.2% (2010/7400), including 71.2% (1431/2010) of numerical aberrations and 28.8% (579/2010) of structural aberrations. Additionally, the detection rate of clinically significant copy number variants (CNVs) was 6.8% (505/7400) and 0.7% (57/7400) for variants of unknown clinical significance. The detection rate of clinically significant submicroscopic CNVs was 7.9% (334/4204) for fetuses with structural anomalies, 5.4% (18/336) in AMA, 3.1% (22/713) in the group of abnormal serum screening and 6.1% (131/2147) in other indications. Using the aCGH method, it was possible to assess the frequency of pathogenic chromosomal aberrations, of likely pathogenic and of uncertain clinical significance, in the groups of cases with different indications for an invasive test.

Evaluation of the types and frequency of unstable chromosomal aberrations induced in lymphocytes of breast cancer patients before and after radiotherapy

Evaluation of the types and frequency of unstable chromosomal aberrations induced in lymphocytes of breast cancer patients before and after radiotherapy

Effect of Gamma Radiation on Cytogenetic and Growth Endpoints of Allium cepa Seedlings in Long-Term Experiments

The effect of γ-radiation on the growth and cytogenetic endpoints of Allium cepa L. seedlings in a long period after irradiation in absorbed doses from 1.0 to 10.7 Gy were examined. The chromosome aberration rate was most sensitive to the radiation: it increased immediately after exposure at all doses. In the recovery period (up to 216 h) after irradiation, the chromosome aberration frequency naturally decreased but at the end of experiment in maximum doses remained above the control values. The impact of the initial level of chromosome aberrations on the inhibition of onion roots growth in the long terms after irradiation is discussed.

Genotoxicity of Glyphosate on Cultured Human Lymphocytes.

Glyphosate-based herbicides are the most used herbicides in the world. Despite being widely used, a dispute exists whether glyphosate-based herbicides have a negative effect on human health, particularly genotoxic effects. Therefore, the aim of this study was to investigate glyphosate genotoxicity on cultured human lymphocytes. Cultured human lymphocytes were treated with different concentrations of glyphosate (20, 40, and 200µmol/L). Four toxicity measures were examined: frequency of chromosomal aberrations (CAs), frequency of sister-chromatid exchange (SCE), production of 8-OHdG, and cell kinetics analysis. The results show that glyphosate induced significant (P < 0.05) increases in the levels of SCE at the highest used concentration (200μmol/L). However, no significant elevation in SCE levels was observed at the lower examined concentrations (20 and 40μmol/L). No significant changes in CA were detected at all examined concentrations (P = 0.86). Also, glyphosate did not induce changes to the normal level of 8-OHdG at all examined concentrations (P = 0.98). Last, no significant changes in either mitotic index or proliferative index were observed at any examined concentrations (P > 0.05). The results collectively indicate a lack of genotoxicity and cytotoxicity of glyphosate in cultured human lymphocytes when dealing with environmentally relevant concentrations (20 and 40μmol/L). However, being exposed to higher concentrations (200μmol/L) led to slightly higher level of SCE. Therefore, we recommend cautionary measures when dealing with glyphosate-based herbicides for individuals, such as farmers, who may be extensively exposed to high concentrations of these herbicides.

In vitro analysis of thimerosal genotoxicity and cytotoxicity effect

Background: Thimerosal is an organomercury compound with high mercury content. Thimerosal is located in the market as an effective bacteriostatic in a series of pharmaceutical products, ophthalmic and nasal products, immunoglobulin preparations, and as a preservative in vaccines. Aims and Objectives: Since it is a compound with living content, this study aimed to examine the genotoxic and cytotoxic potential of thimerosal in human lymphocytes culture. Materials and Methods: We used chromosome aberration analysis and cytokinesis-block micronucleus cytome (CBMN-Cyt) assay to test its genotoxic and cytotoxic potential in human lymphocyte culture. Results: Results showed that the frequency of structural chromosome aberrations and CBMN-cyt assay was significantly increased in treated cultures (1 μg/ml and 0.5 μg/ml) compared to the negative control. Conclusion: Obtained results and statistical analysis show that thimerosal is genotoxic and cytotoxic in human lymphocytes in tested concentrations.

The role of BRCA2 in the fragility of interstitial telomeric sites

We examined frequencies of radiation-induced chromosomal aberrations, using classical cytological methods, and DNA damage in interphase and metaphase cells, using a combination of FISH, CO-FISH, TIF (telomere dysfunction induced assay) and simultaneous detection of DNA damage and telomeric sequences in metaphase chromosomes, in Chinese hamster cells defective in BRCA2 and control cells. Given that the Chinese hamster genome contains large blocks of interstitial telomeric sites, our results allow us to examine the role of BRCA2 in the potential fragility of these sites, but also whether BRCA2 affects DNA repair within terminal telomeric sequences. BRCA2 defective cells exhibited greater frequencies of DNA damage within interstitial telomeric sites, as well as within terminal telomeric sites, relative to control cells. Therefore, BRCA2 deficiency contributes to the telomere dysfunction phenotype in Chinese hamster cells.

Fanconi Anemia Patients from an Indigenous Community in Mexico Carry a New Founder Pathogenic Variant in FANCG.

Fanconi anemia (FA) is a rare genetic disorder caused by pathogenic variants (PV) in at least 22 genes, which cooperate in the Fanconi anemia/Breast Cancer (FA/BRCA) pathway to maintain genome stability. PV in FANCA, FANCC, and FANCG account for most cases (~90%). This study evaluated the chromosomal, molecular, and physical phenotypic findings of a novel founder FANCG PV, identified in three patients with FA from the Mixe community of Oaxaca, Mexico. All patients presented chromosomal instability and a homozygous PV, FANCG: c.511-3_511-2delCA, identified by next-generation sequencing analysis. Bioinformatic predictions suggest that this deletion disrupts a splice acceptor site promoting the exon 5 skipping. Analysis of Cytoscan 750 K arrays for haplotyping and global ancestry supported the Mexican origin and founder effect of the variant, reaffirming the high frequency of founder PV in FANCG. The degree of bone marrow failure and physical findings (described through the acronyms VACTERL-H and PHENOS) were used to depict the phenotype of the patients. Despite having a similar frequency of chromosomal aberrations and genetic constitution, the phenotype showed a wide spectrum of severity. The identification of a founder PV could help for a systematic and accurate genetic screening of patients with FA suspicion in this population.

Effects of Three Widely Used Antibiotics and Their Mixture on the Haemocytes of the Clam Ruditapes philippinarum

Although the presence of pharmaceutical and personal care products in aquatic ecosystems is well documented, little information is available about their sublethal effects, on aquatic invertebrates. From an ecotoxicological point of view, the use of in vitro approaches has been recommended as a tool to assess adverse effects and to understand the mechanisms of action of chemicals at the cellular level. In the present in vitro study, the effects of Amoxicillin (AMX), Trimethoprim (TMP) and Ciprofloxacin (CIP) (1 µg/L, each) were tested alone and—for the first time—as a mixture (MIX) on haemocytes of the clam Ruditapes philippinarum. After the exposure, a battery of cellular parameters was evaluated, such as haemocyte viability, lysosomal membrane stability, superoxide anion production, acid phosphatase activity, the frequency of micronuclei and chromosomal aberrations. The results demonstrated that AMX, TMP, CIP and MIX affected lysosomal membrane stability, as well as superoxide anion and acid phosphatase production, and promoted chromosomal aberrations. This study highlighted that Manila clam haemocytes are a sensitive cell model to assess the effects of exposure to pharmaceutical products on non-target species. Our study demonstrated that the effects of pharmaceutical mixtures on marine species should be experimentally evaluated because they are not predictable from single exposures as the compounds can interact in different ways on the various biological endpoints considered.

The Length of Telomeres and the Baseline Level of Cytogenetic Damage in Leukocytes of Lung Cancer Patients

Despite the great efforts of basic and clinical research on lung cancer (LC), the prevention and treatment of this type of cancer show still far from satisfactory indicators. The complex mechanisms of the LC biology are already recognized, but there is a significant gap in the knowledge about the interaction of key biomarkers in the etiology and progression of this disease. The present work is aimed at studying the relationship between the telomere length (TL) and frequencies of chromosomal aberrations (CA) and micronuclei (MN) in leukocytes of primary lung cancer patients. In 67 men with lung cancer and 77 control donors (men), the baseline frequencies of CA and MN were determined in blood leukocytes, and TL was also studied. As a result, a significant increase in TL was found in lung cancer patients compared with control donors (25.86 ± 2.13 versus 15.29 ± 1.22, respectively, p = 0.00001). In leukocytes of LC patients, a significant increase in the baseline level of structural aberrations of chromosomes, as well as micronuclei containing centromeres, was noted. Only in the sample of lung cancer patients were direct correlations of TL with the frequency of chromosomal type aberrations and with the frequency of paired fragments revealed. In the same sample, significant inverse correlations of TL with the frequency of binucleated leukocytes containing nuclear protrusions and with the frequency of cells entering apoptosis were recorded. The study first showed that an increase in TL in lung cancer patients is associated with structural chromosomal damages, but not with the incidence of aneuploidies.

Spontaneous Chromosomal Aberrations in Lymphocytes and Development of Tumor in Hospital Workers.

Cytogenetic analysis of chromosomes in blood lymphocytes can be used to reveal biomarkers of tumor risk. The frequency of chromosomal aberrations (CAs) appears to correlate with the later incidence of cancer. In our work, a total of 515 healthy Hungarian medical workers and 725 controls were enrolled in our investigation. The CAs in peripheral blood lymphocytes were analyzed. The frequency of CAs was significantly higher in the groups working with ionizing radiation and with cytostatic agents compared to unexposed controls and in male smokers rather than non-smokers. The frequency of dicentric chromosomes, however, was not significantly different between control and exposed groups. Among 82 cancer cases (6.6%), the most frequent types were cancer of the breast (20.5%), colon (12.8%), lung and thyroid gland (9-9%). Our analysis showed 8.1% cancer cases in smokers compared to 5.7% in non-smokers. The potential exposure to carcinogens did not modify the effect of CAs on cancer risk but tobacco smoking did increase risk.

Comparative investigation of toxicity induced by UV-A and UV-C radiation using Allium test.

Organisms are increasingly exposed to ultraviolet (UV) rays of sunlight, due to the thinning of the ozone layer and its widespread use in sterilization processes, especially against the SARS-CoV-2 virus. The present study was conducted with the purpose of evaluating the damages of UV-A and UV-C radiations in Allium cepa L. roots. The effects of two different types of UV on some physiological, biochemical, cytogenotoxic, and anatomical parameters were investigated in a multifaceted study. Three groups were formed from Allium bulbs, one of which was the control group. One of the other groups was exposed to 254 nm (UV-C) and the other to 365 nm (UV-A) UV. Growth retardation effect of UV was investigated with respect to germination percentage, total weight gain, and root elongation, while cytogenotoxicity arisen from UV exposure was analyzed using mitotic index (MI) and chromosomal aberration (CA) and micronucleus (MN) frequency. Oxidative stress due to UV application was investigated based on the accumulation of malondialdehyde (MDA) and the total activities of superoxide dismutase (SOD) and catalase (CAT) enzymes. Also, anatomical changes induced by UV-A and UV-C were analyzed in root meristematic cells. UV treatments caused significant reductions in growth-related parameters. Both UV treatments caused a significant increase in MDA levels and induction of SOD and CAT enzymes in root meristematic cells. A decrease in MI and an increase in the frequency of MN and CAs were observed in root tip cells, indicating the cytogenotoxic effect of UV application. Anatomical damages such as epidermis cell damage, cortex cell damage, necrotic zones, giant cell nucleus, and indistinct transmission tissue occurred in cells exposed to UV. All of the physiological, biochemical, cytogenetic, and anatomical damages observed in this study were more severe in cells treated with UV-C compared to UV-A. This study suggested that UV exposure triggered growth inhibition, cytogenotoxicity, oxidative stress, and meristematic cell damages in A. cepa roots depending on the wavelength.