Total Chromosomal Aberrations Research Articles

Study on the Relativity between Cytogenetics and Cytomorphology and its Prognosis Significance in Children with Acute Myelogenous Leukemia

Objective: The main objective of this study was to retrospectively evaluate that the cytogenetic abnormalities is an important prognostic factor for the cure of acute myeloid leukemia (AML).Methods: This retrospective study enrolled newly diagnosed 70 cases (37 males and 33 females, aged 10.1 months to 14.5 years) of pediatric patients with AML during 2010 January - 2016 February from the Second Affiliated Hospital of Anhui Medical University. Excluding criteria were cases secondary to treatment-related MDS and AML. Samples were obtained from bone marrow cells in patients after treatment on the anterior superior iliac spine, blood diseases laboratory by direct culture or 24/48 hour short-term culture, G -banding technique for testing. Follow-up of 1 - 60 months, the analysis of treatment response rates of different karyotypes, distribution ratios in various subtypes, normal karyotype and abnormal karyotype. ISPSS17.0 software statistics was used for statistical analysis. Groups were compared using chi-square test; Survival rate was calculated by method of Kaplan Meier and survival difference between groups were compared with breslow test.Results: Among 70 cases, 42 cases were detected for chromosomal abnormalities (i.e. 60% of the total number of cases), M3 abnormal karyotype distortion rate of 78.5%, M2 abnormal karyotype aberrations 63.3%, M4 60.0%, M1 50%, M5 lowest 38.9 %, M7 nuclear aberrations highest rate was 100%. Total chromosomal aberration rate was 60%. Acute myeloid leukemia cases, t (8; 21) at most, there are 15 cases, and the presence of abnormal karyotype 86.7% in the original part of differentiated myeloid leukemia (M2); t (15; 17) has 11 cases, exists only in acute promyelocytic cell leukemia (M3). After treatment, the remission rate of t (8; 21) was 80%; the remission rate of t (15; 17) was 90%; the remission rate of other abnormal karyotype abnormalities was 50%; the remission rate of total abnormal karyotype was 71.4%. The event free survival rate was significantly different between normal karyotype, t (8; 21), t (15; 17) and other abnormal karyotype groups (P<0.05).Conclusions: Acute myeloid leukemia karyotype abnormalities among FAB subtypes are different; M3 is the highest rate of abnormal karyotype aberrations, M2, M4 medium, M5 minimum. t (15; 17) seen in acute promyelocytic leukemia (APL), prognosis is good; t (8; 21) is more common in M2, prognosis is good, also found in M4 and M5, worse prognosis; +8 Abnormalities found in AML M2, M3, M4, M5 and M6 subtypes, prognosis medium; inv (16) high white blood cells, low platelet poor prognosis, AML patients with normal karyotype prognosis medium. J-GMC-N | Volume 11 | Issue 01 | January-June 2018, Page: 35-41

Determination of the Genotoxicity of the Soil in the Aydın Region Irrigated by Büyük Menderes River by the Allium Test System

Nowadays, one of the most important problems is environmental pollution. Environmental pollution in the Büyük Menderes River-basin, which is one of the agricultural fields in Turkey, has reached important dimensions. B. Menderes River which waters B. Menderes River-basin and fields around it is contaminated by various sources.In this study the genotoxicity of the soil samples taken from three different regions in two different months (September 2006 and March 2007) in the Aydın region of B. Menderes River-basin was researched with the Allium test.The soil samples were taken from the lands watered by the B. Menderes River and Çine Stream; the fields near the B. Menderes Bridge (on the Muğla main road), the Çine Stream, and the Koçarlı Bridge in September and March. 25%, 50%, 100% concentrations were prepared diluting these samples and onions (Allium cepa L.) were rooted. At the end of the studies, the decrease in the mitotic index was found to be statistically important according to the control in all the doses except 25% of the Çine doses in September and March. The study soil samples taken from the three different regions in two different months caused structural chromosomal aberrations such as anaphase bridge, fragment, stickiness, and polar deviation in the Allium cepa L. root tip cells. It has been emphasized that the difference in all the doses except for 25% Menderes, 25% Koçarlı, 50% doses in September and 25% Çine, 25% Menderes, 25%, 25% Koçarlı, Koçarlı, 50% doses in March are important according to the control in the total chromosomal aberrations.

Genotoxicity of recycled electronic waste in Idhna, Hebron District, occupied Palestinian territory: a case-controlled study

BackgroundElectronics waste is solid waste that accumulates because of the short lifespan of many types of electronic equipment. Most electronics waste ends up in landfills, whereas some is recycled. In the occupied Palestinian territory, the village of Idhna in the Hebron District is a large site for recycling electronics waste (much of this waste originates from Israel). The aim of this study was to evaluate the effects of electronics waste on human DNA damage and chromosome breaks. MethodsIn this cross-sectional study, we recruited non-smoker individuals with direct exposure to electronics waste either because they were employed in the workshops or resident in Idhna. Control participants were selected to match the test sample in age and sex distribution, were recruited from Bethlehem and Al-Aizariya (Bethany). Blood samples in sodium heparin were evaluated for DNA damage using the COMET assay, whereas chromosome aberrations were tested by using conventional cytogenetic techniques. Findings46 participants were included in the test sample, and 16 participants were included in the control sample. Participants in the test sample had an average of 3·77 chromosomes with aberrations (SD 2·5), whereas participants in the control group had an average of 0·75 chromosomes with aberrations (SD 0·61). The frequency of chromatid and chromosome breaks, formation of rings, and total chromosome aberrations was statistically different between exposed and control samples, but no difference was observed between exposed and controls for the incidence of dicenterics and tetraploidy. Results of the Comet assay showed a significant difference in DNA damage between exposed and control participants (p<0·05). No difference between the workers and the residents living in the area was noted (p<0·05). InterpretationExposure to recycled electronics waste in Idhna has potentially adverse health consequences. This is the second study of this kind in the occupied Palestinian territories. Hammad and Qumsiyeh (2013) have previously shown substantial genotoxic effects of Israeli industrial settlement discharge on human populations in Salfit (northern West Bank). Considering increased incidence of cancer and congenital birth defects in the southern part of the West Bank, these findings were important in promoting the case for mitigation measures, which are now under way. FundingNone.

&amp;lt;i&amp;gt;In Vitro&amp;lt;/i&amp;gt; Chromosomal Aberration Frequency by Electrofishing on &amp;lt;i&amp;gt;Poecilia latipinna&amp;lt;/i&amp;gt; (Sailfin Molly) Fishes in Southern of Iraq

The present studies describe Chromosomal aberration effects of electrofishing, which were evaluated on Poecilia latipinna, located in Shat Al-Arab river in Al-garmma city (south of Iraq). The electrofishing derive used in work is simulated to that used in the commercial fishing. The apparatus generates voltage ranged from 40 to 280 volts. Nine bearers of Poecilia latipinna sailfin molly fish in chromosomal analysis were divided into three treatments. The first were a control, the fishes of the second were exposed to 110 volts (10 seconds), and final groups were exposed to 110 volts (15 seconds). Mitotic index of the electrofishing with a control for each group decreased with increasing exposed time in somatic cell kidney tissue of Poecilia latipinna. The chromosome aberration analysis revealed a significant increase in the most frequent aberration per 150 metaphase in analyzed groups (1.33 in T1 groups, 39.33 in T2 groups) was chromosome break, fragment, range chromosome, Sticky chromosome mean, were higher in comparison to non exposed electrical shock fishing groups (control groups T1). At the same time, it showed a higher positive correlation of total chromosome aberration frequencies between T1 and T2 groups, while, all fishes died in T3 groups. According to our results, we represented the first record in Iraq.

Cr3O(O2CCH2CH3)6(H2O)3]NO3·H2O (Cr3) Toxicity Potential in Bacterial and Mammalian Cells.

Chromium(III) has generally been considered to be essential for proper carbohydrate and lipid metabolism, and, despite recent evidence to the contrary, chromium(III)-containing compounds remain one of the most popular commercial dietary supplements. Cr3, or [Cr3O(O2CCH2CH3)6(H2O)3]NO3·H2O, is a trivalent chromium compound that is a promising chromium nutritional supplement. Studies with Cr3 have indicated that it is non-toxic in developmental and short- and long-term exposure studies in rodents, but the safety of this compound to chromosomes and cells has not been explored. The current study evaluates the mutagenicity, cytotoxicity, and clastogenicity of Cr3 in bacterial and mammalian cells and compares these results with similar studies using the bestselling Cr(III) nutritional supplement, chromium picolinate (CrPic). The mutagenicity of CrPic and Cr3 was tested in Escherichia coli FX-11 and Salmonella typhimurium (TA 98 and TA 100). Cytotoxicity was measured as a decrease in plating efficiency relative to controls after treatment with Cr3 and CrPic for 24h in CHO K1 cells. Clastogenicity was measured by counting the number of metaphases damaged and of the total number chromosomal aberrations in CHO K1 cells. Mutagenesis assays in E. coli and S. typhimurium were negative. All treatments of Cr3 produced ≥84% plating efficiency except 80μg/cm2, which reduced the plating efficiency to 62%. Cr3 at any treatment level did not produce a significant increase in the number of cells with abnormal metaphases, while treatments using ≥40μg/cm2 of CrPic elevated the number significantly. These data suggest that Cr3 is significantly less mutagenic in bacteria cells and less clastogenic in CHO K1 cells, while CrPic is clastogenic in CHO K1 cells.

Assessment of the cytotoxicity and genotoxicity properties of Uvaria chamae P. Beauv (Annonaceae) and Morinda lucida Benth (Rubiaceae) in mice

The toxicity profile of medicinal plants is an important preclinical requirement in the development of phytomedicines. The cytotoxic and genotoxic effects of the leaf of Uvaria chamae P. Beauv (Annonaceae) and stem bark of Morinda lucida Benth (Rubiaceae) were investigated in order to provide information on their safety as antimalarial plants. The methanol extract of U. chamae and ethanol (70%) extract of M. lucida were separately orally administered (125, 250, and 750 mg/kg/day) to mice for 10 consecutive days. Cyclophosphamide (50 mg/kg, single dose) and distilled water were used as positive and negative controls, respectively. The mice were injected with colchicine (0.04%) intra-peritoneally 24 h after the last administration of the extracts and the bone marrows harvested. Giemsa-stained slides of bone marrow cells were microscopically assessed for dividing cells to determine the mitotic index (MI) and scored for chromosomal aberrations (CA) according to standard methods. chamae exhibited dose-dependent cytotoxicity. At 750 mg/kg, the MI was significantly (p < 0.05) lower (1.81 ± 0.04) than that of cyclophosphamide (5.83 ± 0.04). The lower the MI, the higher the cytotoxicity. The activity of M. lucida was not significantly different (p > 0.05) from that of the negative control. The total CA observed from treatment with both plants at all doses were significantly (p < 0.05) greater than that of control. This study concluded that U. chamae showed both cytotoxicity and genotoxicity while M. lucida exerted only genotoxic effect. Nevertheless, the two plants should be used with caution in antimalarial therapy.

Coal extraction causes sediment toxicity in aquatic environments in Santa Catarina, Brazil

This study evaluated water parameters in ponds affected by coal extraction. Allium cepa assay was used to measure genotoxicity/mutagenicity of the sediment. Samples were collected from four ponds in the southern state of Santa Catarina. Water temperature, pH, dissolved oxygen, conductivity and turbidity were measured. Sediments were analyzed for heavy metals. Elutriate samples were prepared at a ratio of 1:4 sediment:water. Allium cepa bulbs were placed in samples prepared from each pond, with ultrapure water used as negative control and methyl methane sulfonate as positive control. Root length, mitotic index, chromosomal aberrations, micronuclei, and nuclear abnormalities were measured. The pH of two ponds, as well as electrical conductivity and dissolved oxygen of all ponds were below the minimum limits set by Brazilian regulation. All heavy metals analyzed were found in all sediment samples, but only Cd concentration was above the legal limit set by Brazilian law. Allium cepa root growth for samples from Ponds 1, 2, and 4 was significantly lower than the negative control. Meristematic cells exposed to elutriate samples showed no significant changes in cell division. There was a significant increase in total chromosomal aberrations in all treated samples in comparison with the negative control. This study demonstrates that even low concentrations of heavy metals can damage exposed biota, possibly due to synergistic effects. We also found the A. cepa bioassay to be a simple and useful tool for genotoxicity/mutagenicity analyses, and recommend its use for environmental monitoring and management in areas influenced by mining activities.

Protective effect of Alstonia scholaris Linn. R. Br. against Bleomycin induced chromosomal damage in cultured human lymphocytes, in vitro

It is both interesting and necessary to identify and develop nontoxic radioprotective compounds. Bleomycin (BLM), a known radiomimetic drug was used as a clastogen in the present study. The possible protective effects against BLM (15 μg/ml) induced clastogenicity by aqueous and methanolic extracts from Alstonia scholaris bark, stem and leaves were compared. The treatment of bark extracts significantly (p < 0.01) reduced total chromosomal aberrations. Such a reduction was not seen in case of stem and leaf treatments. The dose of 50 μg/ml was fixed for all extracts throughout the study. To understand the mechanism involved with the protective property of bark extracts, sensitive G2 assay was performed. Lymphocyte cultures from 12 healthy volunteers were exposed to aqueous (50 μg/ml) and methanolic (50 μg/ml) extracts of A. scholaris bark alone as well as in combination with Bleomycin under two different growth phases, G0 and G2. There was a statistically significant reduction (p < 0.05) in the total chromatid breaks in all cultures which were exposed at G2 phase as compared to respective cultures exposed at G0 phase. The highest level (p < 0.0001) of reduction in total chromatid breaks was observed in cultures treated with aqueous bark extracts at G2 phase than those at G0 phase. This indicated that there could be certain compound(s) present in aqueous bark extracts which enhance DNA repair capacity. Therefore, the bark of A. scholaris could be further utilized to identify and bring out front line radio protective agents in the market with effective formulations.

RRx-001 protects against cisplatin-induced toxicities.

RRx-001, a minimally toxic tumor-associated macrophage and neutrophil-repolarizing agent, is under investigation in Phase II clinical trials as a sensitizer/resensitizer to cisplatin and carboplatin. On the basis of anecdotal clinical observations of improved platinum tolerability following a priming period with RRx-001 as well as preclinical studies that have previously demonstrated radioprotection of intestinal stem cells and cardioprotection from doxorubicin, the in vivo cytoprotective potential of RRx-001 pretreatment against cisplatin-induced bone marrow suppression and renal toxicity was investigated. BALB/c mice were divided into three groups: (1) no treatment, (2) vehicle and cisplatin only, and (3) RRx-001 and cisplatin. RRx-001 treatment (5mg/kg every other day for 3days) was initiated 3days prior to cisplatin administration. Blood was collected from the femoral vein at different intervals to measure total hemoglobin and leukocyte counts as well as renal functional markers (serum urea, creatinine and creatinine clearance). Metaphase spreads were prepared from whole bone marrow cells as markers of clastogenicity. RRx-001 pretreatment significantly decreased (P<0.05) the blood urea nitrogen and creatinine levels. A statistically significant (P<0.05) reduction in the mean total chromosome aberration frequency per metaphase in the RRx-001 and cisplatin group compared to the cisplatin-only group was observed. This study is the first to demonstrate that RRx-001 has nephro-, geno- and myeloprotective effects in vivo. Importantly, RRx-001 did not protect sarcoma-180 solid tumor xenografts against cisplatin-induced cytotoxicity. These results potentially support the use of RRx-001 as a chemoprotector against cisplatin-induced toxicities.

Chromosome aberrations frequency in peripheral blood lymphocytes in young tobacco smoking and non-smoking people

Introduction: Cigarette smoking is associated with severe health problems, especially cancers. In addition, cigarette smoking causes different genotoxic effects. Chromosome aberrations are one of well-known intermediate end points in carcinogenesis. The aim of this study was to compare frequencies of chromosome aberrations in peripheral blood lymphocytes between young smokers and non-smokes groups.Methods: The study was conducted with 30 smokers (average age 26.93 years) and 30 non-smokers (average age 26.96 years), and included the analysis of 100 metaphases per each blood sample. Differences in the arithmetic means of determined frequencies of chromosome aberrations were tested by two-tailed t-test for independent samples with the significance level of p &lt; 0.05.Results: The results showed a significant increase in the frequencies of chromatid-type aberrations and total structural chromosome aberrations in smoker group. Frequencies of numerical aberrations did not differ significantly between two groups.Conclusions: This study confirmed genotoxicity of cigarette smoking and provided new evidence about its clastogenic activity.

Chromosomal aberrations, sister chromatid exchanges, and micronuclei in lymphocytes of oncology department personnel handling anti-neoplastic drugs

Objective: Concern exists regarding the possible hazards to the personnel handling anti-neoplastic drugs. The purpose of the present study was to assess the genotoxicity induced by anti-neoplastic agents in oncology department personnel. Materials and methods: To do this, the frequency of chromosomal aberrations (CAs) induced in peripheral blood lymphocytes was assessed at G0 phase of the cell cycle using metaphase analysis, cytokinesis block-micronucleus (MN) assay and sister chromatid exchange (SCE) assay. These cytogenetic end points were measured among 71 nurses in oncology department and 10 drugstore personnel handling and preparing anti-neoplastic drugs. The results were compared to those of 74 matched nurses for age and sex not exposed to any anti-neoplastic agents. Results: There was no significant difference between the age of study subjects and control group (p > 0.05). The results showed that the mean frequency of cytogenetic damages in terms of CAs [chromatid breaks (p = 0.01), chromosome breaks (p = 0.005), total CAs (p = 0.001)], MN formation (p = 0.001), and SCE (p = 0.004) in lymphocytes of personnel handling anti-neoplastic drugs were significantly higher than those in control unexposed group. Conclusion: Results of the present study demonstrate the cytogenetic damage in peripheral blood lymphocytes of oncology department personnel. Suitable training and proper knowledge when handling anti-neoplastic drugs are emphasized to avoid potential health hazards caused by cytostatic agents.

Association between exposure to nitric oxide and changes in select molecular markers of health among men in the gold jewelry manufacturing industry

Gold jewelry workers are occupationally exposed to nitric oxide (NO) during the purification of gold. The present study involves the evaluations of chromosome aberrations (CA), micronucleus (MN) and comet assay in lymphocytes and identifies the influence of polymorphisms in DNA repair genes (XRCC1280Arg/His, XRCC1399Arg/Gln) among the gold jewelry workers occupationally exposed to nitric oxide (NO). Among the 84 samples undertaken for study, the non-exposed (categorized based only on age being group I <35years; group II ≥35 years) and exposed subjects (categorized based on age and work duration) constituted 42 subjects each. With increase duration of years of exposure, an increased level of chromosomal damage was observed. Likewise, a higher degree of chromosomal damage and MN was observed in exposed subjects of group II with a total CA of 8.07 ± 3.29 and MN of 10.61 ± 2.25 when compared to group I. Significant increases were also indicated with the overall CA frequency for the exposed subjects for chromatid, chromosome type aberrations and the MN/1000 binucleated cells in peripheral lymphocytes (p < 0.05) in comparison with non-exposed. The analysis of mean tail length of comet assay shows the DNA damage among the group II exposed subjects exhibits higher degree of chromosomal damage, indicating chronic exposure of NO causes the genetic modification, largely influenced by the polymorphic genotypes XRCC1280Arg/His (p < 0.001) and XRCC1399Arg/Gln (0.524). In conclusion, this result of work provides evidence for an apparent genotoxic effect associated with NO exposure. Our result reinforces the higher sensitivity of cytogenetic assays for the biomonitoring of occupationally exposed populations. So there is a strong need to educate those who work with potentially hazardous heavy metals about their adverse effects and highlight the importance of using protective measures.

Application of an integrated biomarker response index to assess ground water contamination in the vicinity of a rare earth mine tailings site.

We utilized a multi-biomarker approach (Integrated Biomarker Response version 2, IBRv2) to investigate the scope and dispersion of groundwater contamination surrounding a rare earth mine tailings impoundment. Parameters of SD rat included in our IBRv2 analyses were glutathione levels, superoxide dismutase, catalase, and glutathione peroxidase activities, total anti-oxidative capacity, chromosome aberration, and micronucleus formation. The concentration of 20 pollutants including Cl(-), SO4 (2-), Na(+), K(+), Mg(2+), Ca(2+), TH, CODMn, As, Se, TDS, Be, Mn, Co, Ni, Cu, Zn, Mo, Cd, and Pb in the groundwater were also analyzed. The results of this study indicated that groundwater polluted by tailings impoundment leakage exhibited significant ecotoxicological effects. The selected biomarkers responded sensitively to groundwater pollution. Analyses showed a significant relationship between IBRv2 values and the Nemerow composite index. IBRv2 could serve as a sensitive ecotoxicological diagnosis method for assessing groundwater contamination in the vicinity of rare earth mine tailings. According to the trend of IBRv2 value and Nemerow composite index, the maximum diffusion distance of groundwater pollutants from rare earth mine tailings was approximately 5.7km.

Cytogenetic and dosimetric effects of 131I in patients with differentiated thyroid carcinoma: comparison between stimulation with rhTSH and thyroid hormone withdrawal treatments

A study directed to the cytogenetic and dosimetric aspects of radionuclides of medical interest is very valuable, both for an accurate evaluation of the dose received by the patients, and consequently of the genetic damage, and for the optimization of therapeutic strategies. Cytogenetic and dosimetric effects of (131)I in lymphocytes of thyroidectomized differentiated thyroid cancer (DTC) patients were evaluated through chromosome aberration (CA) technique: Euthyroid patients submitted to recombinant human thyroid-stimulating hormone (rhTSH) therapy (group A) were compared with hypothyroid patients left without levothyroxine treatment (group B). CA analysis was carried out prior to and 24h, 1week, 1month and 1year after radioiodine administration (4995-7030MBq) in both groups. An activity-response curve of (131)I (0.074-0.740MBq/mL) was elaborated, comparing dicentric chromosomes in vivo and in vitro in order to estimate the absorbed dose through Monte Carlo simulations. In general, radioiodine therapy induced a higher total CA rate in hypothyroid patients as compared to euthyroid patients. The frequencies of dicentrics obtained in DTC patients 24h after treatment were equivalent to those induced in vitro (0.2903±0.1005MBq/mL in group A and 0.2391±0.1019MBq/mL in group B), corresponding to absorbed doses of 0.65±0.23Gy and 0.53±0.23Gy, respectively. The effect on lymphocytes of internal radiation induced by (131)I therapy is minimal when based on the frequencies of CA 1year after the treatment, maintaining a higher quality of life for DTC patients receiving rhTSH-aided therapy.

Protective effects of pomegranate peel against hematotoxicity, chromosomal aberrations, and genotoxicity induced by barium chloride in adult rats

Context Pomegranate peel (PP) has health benefits including antibacterial, antioxidant, anti-inflammatory, and antimutagenic properties. Objective This study investigated the biochemical composition and protective effects of PP against hematotoxicity and genotoxicity induced by barium chloride (BaCl2) in adult rats. Materials and methods Adult Wistar rats were divided into four groups of six each: control, barium (67 ppm via drinking water), PP (5% via diet), and their combination during 21 d. Oxidative stress was determined by MDA, AOPP, and antioxidant status: CAT, GPx, GSH, Vit C. Osmotic fragility (OF), chromosomal aberrations (CAs), and micronucleus (MN) assays were also studied. Results PP showed a rich composition of antioxidant compounds. DPPH test found IC50 value= 5.3 μg/mL and a high polysaccharides content (315 ± 5 mg/g of extract). In vivo study showed a decrease in red blood cells (70%) and platelet counts (46%), hemoglobin content (8%), hematocrit percent (7%), and an 80% increase of white blood cells in Ba-treated rats. A reduction in antioxidant status: catalase, glutathione peroxidase activities, glutathione, and vitamin C levels by 31, 21, 28, and 29%, respectively, and an increase in MDA (46%) and AOPP levels (72%) were also observed compared with controls. BaCl2-treatment showed a significant increase in the frequencies of total chromosomal aberrations with abnormal metaphases and micronucleus in bone-marrow cells. Oxidative stress induced by BaCl2 might be the major cause for chromosomal abnormalities leading to DNA damage. Discussion and conclusion A decrease in hematotoxic and genotoxic effects induced by PP is due to its powerful antioxidant capacity.

CYTOGENETIC EFFECTS OF LOW NEUTRON DOSES IN MAMMALIAN CELLS

Актуальность. В связи с облучением больших групп людей в малых дозах при лечебных и диагностических процедурах и потребностью прогнозирования канцерогенного риска облучения представляется актуальным изучение закономерностей биологических эффектов малых доз радиации. Относительно мало исследованы особенности биологического действия нейтронного излучения и его эффекты на цитогенетическом уровне в области малых доз, при этом они могут быть важны при проведении нейтронной терапии и разработке нормативных документов по радиационной защите на ускорителях ионов, в том числе терапевтического назначения.Цель – изучение закономерностей образования структурных повреждений хромосом в клетках млекопитающих при действии быстрых нейтронов в области доз до 1 Гр.Материал и методы. Цитогенетическую эффективность нейтронов с энергией 14,5 МэВ исследовали на лимфоцитах крови человека и клетках китайского хомячка СНО-К1. Диапазон доз нейтронов составлял 0,1–1,2 Гр, мощностей доз – 0,3–60 мГр/мин, частота следования импульсов – 50, 5, и 0,017 Гц. Приготовление препаратов хромосом проводили по общепринятым стандартным методикам. При анализе учитывали весь спектр аберраций хромосом. Результаты. В исследованном диапазоне доз нейтронов для обеих клеточных культур наблюдалась одинаковая закономерность: резкий подъем выхода аберраций хромосом при дозах 0,12–0,15 Гр, замедление роста числа аберраций с увеличением дозы нейтронов до 0,3–0,5 Гр, далее стандартная дозовая зависимость. Указанная закономерность выявлена как по суммарной частоте аберраций хромосом, так и по частоте дицентриков (лимфоциты) и парных фрагментов (СНО-К1). Заключение. Полученные результаты свидетельствуют о проявлении феномена гиперчувствительности и индуцированной радиорезистентности в клетках лимфоцитов человека и китайского хомячка при действии нейтронов с энергией 14,5 МэВ.

Genotoxic potential of Cynanchum sarcomedium Meve &amp; Liede coupled with its modulatory action on oxidative-stress–mediatedgenotoxicity by hydrogen peroxide

The present study evaluated the genotoxic effect of aqueous extract of C. sarcomedium Meve and Liede and its protective role in chromosomal aberrations induced by 2% hydrogen peroxide (H2O2) on Allium cepa root meristem. Our results showed that the C. sarcomedium extract induced major chromosomal aberrations, viz., nuclear lesions, chromosome breaks, chromosome laggards, vagrance, stickiness, and bridges. These are irreversible in nature and indicate that the plant is a potent clastogen. Total chromosome aberrations were more frequent with increase in exposure time and concentrations of plant extract. For antigenotoxic screening, three different modes of treatment were used: pretreatment, posttreatment, and simultaneous treatment. The significant induction of a wide spectrum of chromosomal aberrations and the reduction in mitotic index effected by the aqueous extract reinforced the genotoxic potential of the plant. The modulatory effect of plant extract was expressed in terms of inhibition percentage and had an excellent effect in reversing chromosomal aberrations induced by H2O2. Dose-dependent results suggest the genotoxic and antigenotoxic effect of C. sarcomedium on onion root tips. These findings offer a useful basis for further investigations on C. sarcomedium, a shrub with a broad array of prospective therapeutic activities.

Analysis of Chromosomal Aberrations in PBL of Chrome Tanning Industrial Workers

In order to monitor the geno-toxic effects of chromium compound, 160 chrome tanning industrial workers (80 each of smoker and non-smoker) were selected from a leather tanning industry to perform the cytogenetic protocol of chromosomal aberrations in the peripheral blood lymphocytes. The workers were further classified into two groups on the basis of their personnel habit (Smoker and Non-Smokers) and on the duration of their employment (1-5, 6-10 and 11-15 years). Even 120 individuals (62 smokers and 58 non-smokers) were also selected as controls for the purpose of comparison. A statistically significant increased frequency of total chromosomal aberrations was observed in the chrome tannery workers (6.20 ± 0.12) as against the control (1.61 ± 0.09). The increased frequencies of aberrations were duration dependent. Even higher incidence of chromosome aberrations was reported among the smoker group of both control and exposed workers. The results clearly establish the mutagenic nature of the chromium compound in human beings.

Cytogenetic Analysis on the Yields of Chromosomal Aberrations Induced by the Scattered Doses of γ-Radiation

The present study is undertaken to know the radiation dose-response of chromosomes in the non-target cells, viz. peripheral blood lymphocytes of cancer patients in a context of partial body irradiation. The genotoxic effect of γ- radiation was studied in Head and Neck Squamous Cell Carcinoma (HNSCC) patients exposed to various cumulative doses of 60Co gamma rays during radiotherapy (RT). These patients (P1 to P10) were irradiated for a period of six weeks with a daily fraction of 2 Gy, consecutively for 5 days in every week. The clastogenic effects of radiation in these patients were analysed on every weekend employing chromosomal aberration (CA) assay. Radiosensitivity of these patients were analysed by employing linear regression analysis of the CAs induced by irradiation. Genetic damage observed in all patients on a weekly basis were recorded and analysed at the individual level in comparison with their own pre-therapy baseline data, employing student’s t-test. Dicentrics, centric rings and chromatid breaks were observed as the major kinds of CAs. The total CAs observed were analyzed using two way ANOVA, showed significant (P<0.001) intra and inter-individual variations of the genotoxic effects. Further, a dose dependent increase of cytogenetic damage was observed in the non-target cells viz. lymphocytes. Further, cytogenetic studies in peripheral lymphocytes following gamma radiotherapy of tumors may help to understand the optimum/precise dose of radiation to be employed for RT, may also be useful to predict dosimetry and the possible secondary tumors in irradiated HNSCC patients.

Efficacy of Allium cepa test system for screening cytotoxicity and genotoxicity of industrial effluents originated from different industrial activities.

Efficacy of Allium cepa test system for screening cytotoxicity and genotoxicity of treated effluents originated from four types of industrial activities (two textile industries, three rubber based industries, two common treatment plants of industrial zones, and two water treatment plants) was assessed. Physico-chemical parameters including the heavy metal/metalloid levels of the effluents varied depending on the industry profile, but most of the measured parameters in the effluents were within the specified tolerance limits of Sri Lankan environmental regulations for discharge of industrial effluents into inland surface waters. In the A. cepa test system, the undiluted effluents induced statistically significant root growth retardation, mitosis depression, and chromosomal aberrations in root meristematic cells in most cases in comparison to the dilution water and upstream water signifying effluent induced cytotoxicity and genotoxicity. Ethyl methane sulphonate (a mutagen, positive control) and all the effluents under 1:8 dilution significantly induced total chromosomal aberrations in root meristematic cells in comparison to the dilution water and upstream water indicating inadequacy of expected 1:8 dilutions in the receiving waters for curtailing genotoxic impacts. The results support the use of a practically feasible A. cepa test system for rapid screening of cytotoxicity and genotoxicity of diverse industrial effluents discharging into inland surface waters.