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Sample records for chromosome aberrations induced

  1. Chromosomal aberration

    International Nuclear Information System (INIS)

    Chromosomal aberrations are classified into two types, chromosome-type and chromatid-type. Chromosom-type aberrations include terminal deletion, dicentric, ring and interstitial deletion, and chromatid-type aberrations include achromatic lesion, chromatid deletion, isochromatid deletion and chromatid exchange. Clastogens which induce chromosomal aberration are divided into ''S-dependent'' agents and ''S-independent''. It might mean whether they can induce double strand breaks independent of the S phase or not. Double strand breaks may be the ultimate lesions to induce chromosomal aberrations. Caffeine added even in the G2 phase appeared to modify the frequency of chromatid aberrations induced by X-rays and mitomycin C. Those might suggest that the G2 phase involves in the chromatid aberration formation. The double strand breaks might be repaired by ''G2 repair system'', the error of which might yield breakage types of chromatid aberrations and the by-pass of which might yield chromatid exchanges. Chromosome-type aberrations might be formed in the G1 phase. (author)

  2. Chromosomal aberrations induced by alpha particles

    International Nuclear Information System (INIS)

    The chromosomal aberrations produced by the ionizing radiation are commonly used when it is necessary to establish the exposure dose of an individual, it is a study that is used like complement of the traditional physical systems and its application is only in cases in that there is doubt about what indicates the conventional dosimetry. The biological dosimetry is based on the frequency of aberrations in the chromosomes of the lymphocytes of the individual in study and the dose is calculated taking like reference to the dose-response curves previously generated In vitro. A case of apparent over-exposure to alpha particles to which is practiced analysis of chromosomal aberrations to settle down if in fact there was exposure and as much as possible, to determine the presumed dose is presented. (Author)

  3. Gametocidal chromosomes enhancing chromosome aberration in common wheat induced by 5-azacytidine.

    Science.gov (United States)

    Su, W-Y; Cong, W-W; Shu, Y-J; Wang, D; Xu, G-H; Guo, C-H

    2013-01-01

    The gametocidal (Gc) chromosome from Aegilops spp induces chromosome mutation, which is introduced into common wheat as a tool of chromosome manipulation for genetic improvement. The Gc chromosome functions similar to a restriction-modification system in bacteria, in which DNA methylation is an important regulator. We treated root tips of wheat carrying Gc chromosomes with the hypomethylation agent 5-azacytidine; chromosome breakage and micronuclei were observed in these root tips. The frequency of aberrations differed in wheat containing different Gc chromosomes, suggesting different functions inducing chromosome breakage. Gc chromosome 3C caused the greatest degree of chromosome aberration, while Gc chromosome 3C(SAT) and 2C caused only slight chromosome aberration. Gc chromosome 3C induced different degrees of chromosome aberration in wheat varieties Triticum aestivum var. Chinese Spring and Norin 26, demonstrating an inhibition function in common wheat. PMID:23884766

  4. Chromatin structure and ionizing-radiation-induced chromosome aberrations

    International Nuclear Information System (INIS)

    The possible influence of chromatic structure or activity on chromosomal radiosensitivity was studied. A cell line was isolated which contained some 105 copies of an amplified plasmid in a single large mosquito artificial chromosome (MAC). This chromosome was hypersensitive to DNase I. Its radiosensitivity was some three fold greater than normal mosquito chromosomes in the same cell. In cultured human cells irradiated during G0, the initial breakage frequency in chromosome 4, 19 and the euchromatic and heterochromatic portions of the Y chromosome were measured over a wide range of doses by inducing Premature Chromosome Condensation (PCC) immediately after irradiation with Cs-137 gamma rays. No evidence was seen that Y heterochromatin or large fragments of it remained unbroken. The only significant deviation from the expected initial breakage frequency per Gy per unit length of chromosome was that observed for the euchromatic portion of the Y chromosome, with breakage nearly twice that expected. The development of aberrations involving X and Y chromosomes at the first mitosis after irradation was also studied. Normal female cells sustained about twice the frequency of aberrations involving X chromosomes for a dose of 7.3 Gy than the corresponding male cells. Fibroblasts from individuals with supernumerary X chromosomes did not show any further increase in X aberrations for this dos. The frequency of aberrations involving the heterochromatic portion of the long arm of the Y chromosome was about what would be expected for a similar length of autosome, but the euchromatic portion of the Y was about 3 times more radiosensitive per unit length. 5-Azacytidine treatment of cultured human female fibroblasts or fibroblasts from a 49,XXXXY individual, reduced the methylation of cytosine residues in DNA, and resulted in an increased chromosomal radiosensitivity in general, but it did not increase the frequency of aberrations involving the X chromosomes

  5. Anti-topoisomerase drugs as potent inducers of chromosomal aberrations

    Directory of Open Access Journals (Sweden)

    Loredana Bassi

    2000-12-01

    Full Text Available DNA topoisomerases catalyze topological changes in DNA that are essential for normal cell cycle progression and therefore they are a preferential target for the development of anticancer drugs. Anti-topoisomerase drugs can be divided into two main classes: "cleavable complex" poisons and catalytic inhibitors. The "cleavable complex" poisons are very effective as anticancer drugs but are also potent inducers of chromosome aberrations so they can cause secondary malignancies. Catalytic inhibitors are cytotoxic but they do not induce chromosome aberrations. Knowledge about the mechanism of action of topoisomerase inhibitors is important to determine the best anti-topoisomerase combinations, with a reduced risk of induction of secondary malignancies.As topoisomerases de DNA catalisam alterações topológicas no DNA que são essenciais para a progressão do ciclo celular normal e, portanto, são um alvo preferencial para o desenvolvimento de drogas anticâncer. Drogas anti-topoisomerases podem ser divididas em duas classes principais: drogas anti-"complexos cliváveis" e inibidores catalíticos. As drogas anti-"complexos cliváveis" são muito eficazes como drogas anticancerígenas, mas são também potentes indutores de aberrações cromossômicas, podendo causar neoplasias malignas secundárias. Inibidores catalíticos são citotóxicos mas não induzem aberrações cromossômicas. Conhecimento a respeito do mecanismo de ação de inibidores de topoisomerases é importante para determinar as melhores combinações anti-topoisomerases, com um reduzido risco de indução de neoplasias malignas secundárias.

  6. Chromosomal geometry in the interface from the frequency of the radiation induced chromosome aberrations

    International Nuclear Information System (INIS)

    Ionizing radiation induces DNA double-strand breaks (DSBs) and their interaction and illegitimate recombination produces chromosomal aberrations. Stable chromosomal aberrations comprise inter-chromosomal events (translocations) and intra-chromosomal events (inversions). When DSBs induction and interaction is done at random, and the proximity effects are neglected, the expected relation between translocations and inversions is F=86, based on chromosome arm length. The number of translocations and inversions is analyzed by using G-banding in 16 lymphocytes cultures from blood samples acutely irradiated with γ-rays (dose range: 0,5 Gy - 3 Gy). The result obtained was: F=13,5, significantly smaller than F=86. Literature data show similar small F values, but strongly spread. The excess of inversions could be explained by a 'proximity effect', it means that more proximate DSBs have more interaction probability. Therefore, it is possible to postulate a special chromosome arrangement during irradiation and the subsequent interval. We propose a model where individual chromosomes show spherical confinement with some degree of overlapping and DSBs induction proportional to cross section. A DSBs interaction probability function with cut-off length= 1μ is assumed. According to our results, the confinement volume is ≅ 6.4% of the nuclear volume. Nevertheless, we presume that large spread in F data could be due to temporal variation in overlapping and spatial chromosomal confinement. (authors). 14 refs

  7. Radiation-induced chromosome aberrations in human lymphocytes

    International Nuclear Information System (INIS)

    Dose-response relationships for unstable chromosome exchange aberrations were obtained after irradiation with 200 kV X-rays and 60Co gamma rays, the doses ranging within 0.05-3.0 Gy. The data points were fitted to the linear quadratic model Y = C + αD + βD2, and after the chromosome hits leading to two-break unstable aberrations were estimated, to the model average x = C +kD. The results fitted the latter model particularly well, the index of determination being 0.988 for gamma rays and 0.997 for X-rays. The RBE of 200 kV X-rays as compared with 60Co gamma radiation was 1.6, when primary chromosome breaks leading to dicentric and centric ring aberrations were used as the biological endpoint. (author)

  8. Radiation induced chromosomal aberrations after cardiac catheterization and angiocardiography

    International Nuclear Information System (INIS)

    The relationship between the radiation doses and the chromosomal aberrations of peripheral lymphocytes was studied in patients under-going catheterization with or without angiocardiography. The radiation doses were estimated and chromosomal aberration analyses were carried out in 17 cases. They consisted of 10 males and 7 females at the age of 4 to 26 years with an average of 14 years. Doses in the chest and gonadal regions were measured with calibrated thermoluminescent dosimeters. Peripheral blood samples were taken immediately before and after the diagnostic procedure for chromosome analyses. Results showed that the average doses in the gonad region during cardiac catheterization with and without angiocardiography were 2.4 and 0.83 kC/kg respectively, while those in the chest region were as high as 0.93 and 0.54 kC/kg respectively. The chromosome aberration rate in both groups were significantly higher (2.75-3.33%) than the control value (0.22-0.75%) which was determined before X ray examination. No statistically significant difference of chromosome aberration yield was found between the two groups with and without angiocardiography

  9. Cytogenetic effects of radiotherapy. Breakpoint distribution in induced chromosome aberrations

    International Nuclear Information System (INIS)

    A total of 660 breakpoints were identified in the chromosome aberrations detected in lymphocytes from cancer patients after radiotherapy. The results show that chromosomes 1, 3, and 7 were significantly more affected than other chromosomes by ionizing radiation in vivo. Chromosome arms 1p, 1q, 7q, and 11p were also significantly more affected. Some bands also showed a special sensitivity to radiation, and band 1q32 was the most affected. This band is proposed as a hot point for the clastogenic effect of ionizing radiation. A significant clustering of breakpoints in G bands was also found, especially at the telomeres, as previously described by other authors. Clustering of breakpoints was also observed in bands where fragile sites, protooncogenes, breakpoints involved in chromosomal cancer rearrangements, and breakpoints involved in chromosomal evolution of the Hominoidea are located

  10. The relationship between induced chromosome aberrations and chromosome abnormality in tumour cells

    International Nuclear Information System (INIS)

    The occurrence of chromosome abnormalities in cancer cells and the induction of chromosome aberrations by many different carcinogenic agents are now well established facts and there are many detailed studies in both areas. It is known, however, whether or not there is any relationship between the induced aberrations and those seen in tumours. The purpose of this paper is to consider any evidence which might suggest that such a relationship does exist and the significance that this would have in the genesis of neoplasia. There are at least four chromosomal situations in human tumours: (a) cytogenetically normal, (b) clonal but unique, (c) clonal and specific for a particular neoplasm, (d) clonal and common to some tumours of different types. Any theory that we develop must take account of all four situations. A number of different suggestions have been made to try to explain the observation of chromosome abnormalities in human tumours. The one feature that does seem common to all situations is clonal evolution. A modified somatic mutation hypothesis to account for the chromosome changes occurring before and after malignant transformation is suggested

  11. Chromosome aberrations induced in human lymphocytes by neutron irradiation

    International Nuclear Information System (INIS)

    In vitro dose-response curves of unstable chromosome aberrations in human lymphocytes have been obtained for neutron spectra of mean energies 0.7, 0.9, 7.6 and 14.7 MeV. The aberration yields have been fitted to the quadratic function Y = αD + βD2, which is consistent with the single-track and two-track model of aberration formation. However with high-LET radiation, the linear component of yield, corresponding to damage caused by single tracks, predominates, and this term becomes more dominant with increasing LET, so that for fission spectrum neutrons the relationship is linear, Y = αD. At low doses, such as those received by radiation workers, limiting r.b.e. values between 13 and 47 were obtained relative to 60Co γ-radiation. At higher doses, as used in radiotherapy, the values were much lower; ranging from 2.7 to 8 at 200 rad of equivalent γ-radiation. Both sets of r.b.e. values correlated well with track-averaged LET but not with dose-averaged LET. When the numbers of cells without aberrations were plotted against radiation dose, curves were obtained which are similar in shape to those for conventional cell-survival experiments with comparable neutron spectra. The D0 values obtained in the present study are close to those from other cell systems. (author)

  12. ANALYSES OF CHROMOSOME ABERRATIONS IN LYMPHOCYTES AND BONE MARROW CELLS INDUCED BY RADIATION OR BENZENE

    Institute of Scientific and Technical Information of China (English)

    张鸿源; 王兰金; 等

    1995-01-01

    The chromosomoe and chromatid type aberration can be induced by benzene and the dicentric and ring ones were not observed in vitro experiment but observed in vivo one.In vitro experiment a good linear reression can be given between benzene concentrations and total aberration cells while power regression for radiation dose.The chromosome aberrations induced by benzene combined with radiation in rabbit blood lymphocytes are higher than in bone marryow cells.

  13. X-ray-induced chromosome aberrations in Down lymphocytes: an explanation of their increased sensitivity

    International Nuclear Information System (INIS)

    Unstimulated lymphocytes from individuals with Down Syndrome (trisomy 21) are more sensitive to the induction of dicentric and ring aberrations by X rays than normal lymphocytes. Several explanations involving the more rapid rejoining of X-ray-induced lesions in Down cells have been offered. It is shown here that the repair of the DNA damage converted into chromosome aberrations is more rapid in Down cells than normal cells. This more rapid repair results in a higher probability of producing chromosome aberrations, and hence higher aberration frequencies in Down than normal cells

  14. X-ray-induced chromosome aberrations in Down lymphocytes: an explanation of their increased sensitivity

    International Nuclear Information System (INIS)

    Unstimulated lymphocytes from individuals with Down Syndrome (trisomy 21) are more sensitive to the induction of dicentric and ring aberrations by X rays than normal lymphocytes. Several explanations involving the more rapid rejoining of X-ray--induced lesions in Down cells have been offered. It is shown here that the repair of the DNA damage converted into chromosome aberrations is more rapid in Down cells than normal cells. This more rapid repair results in a higher probability of producing chromosomes aberrations, and hence higher aberration frequencies in Down than normal cells

  15. Proton and Fe Ion-Induced Early and Late Chromosome Aberrations in Different Cell Types

    Science.gov (United States)

    Lu, Tao; Zhang, Ye; Yeshitla, Samrawit; Bowler, Deborah; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2016-01-01

    Genomic instability, induced by various metabolic, genetic, and environmental factors, is the driving force of tumorigenesis. Radiation exposure from different types of radiation sources induces different types of DNA damages, increases mutation and chromosome aberration rates, and increases cellular transformation in vitro and in vivo experiments. The cell survival rates and frequency of chromosome aberrations depend on the genetic background and radiation sources. To further understand genomic instability induced by charged particles, we exposed human lymphocytes ex vivo, human fibroblast cells, human mammary epithelial cells, and bone marrow cells isolated from CBA/CaH and C57BL/6 mice to high energy protons and Fe ions, and collected chromosomes at different generations after exposure. Chromosome aberrations were analyzed with fluorescent in situ hybridization with whole chromosome specific probes.

  16. Antipain-mediated suppression of X-ray-induced chromosomal aberrations in human lymphocytes

    International Nuclear Information System (INIS)

    The protease inhibitor antipain is known to modulate the number of chromosomal aberrations induced by the S-phase-dependent alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine. Experiments have now been carried out to see if antipain might also affect the yield of aberrations induced by X-rays, which are S-independent and thus produce chromosomal aberrations by a different mechanism. The results show that human lymphocytes exposed to 0.4 or 1.5 Gy of X-rays at 48 h of culture and fixed at 3, 6, 8, 10 or 12 h thereafter contain 27-52% fewer chromatid breaks if the cells are also treated with antipain before irradiation. Because previous studies postulated that antipain could affect the induction of of chromosomal aberrations by suppressing free radical reactions within cells, we also tested whether antipain affects X-ray-induced aberrations when present only during the time of irradiation, as is the case for free radical scavengers, such as L-cysteine. The results indicate that, in contrast to L-cysteine, antipain can suppress the induction of X-ray-induced aberrations even when administered as late as 2 h after irradiation, suggesting that the effects of antipain on aberrations are not attributable to its interference with short-lived radicals within the cells. These data indicate that the formation of chromosome aberrations by S-independent agents can involve an antipain-sensitive process. (author)

  17. Protective Effect of Curcumin on γ - radiation Induced Chromosome Aberrations in Human Blood Lymphocytes

    International Nuclear Information System (INIS)

    The present work is aimed at evaluating the radioprotective effect of curcumin on γ radiation induced genetic toxicity. The DNA damage was analyzed by the frequencies of chromosome aberrations assay. Human lymphocytes were treated in vitro with 5.0 γg/ml of curcumin for 30 min at 37 degree C then exposed to 1, 2 and 4 Gy gamma-radiation. The lymphocytes which were pre-treated with curcumin exhibited a significant decrease in the frequency of chromosome aberration at 1 and 2 Gy radiation-induced chromosome damage as compared with the irradiated cells which did not receive the curcumin pretreatment. Thus, pretreatment with curcumin gives protection to lymphocytes against γ-radiation induced chromosome aberration at certain doses. (author)

  18. [Revision of th distribution of chromosome aberrations induced by chemical mutagens using the BUDR label].

    Science.gov (United States)

    Chebotarev, A N; Chernyshova, N A

    1990-08-01

    Cell distribution was analysed with the help of the BrDU label for the number of chromosome aberrations and breaks induced by one-center (thiophosphamide and phosphamide) and two-center (dipine and fotrine) mutagens at the stage G0 in the Ist mitosis of human lymphocytes harvested at different times of culturing (from 56 to 96 h). The comparison was made between the type of aberration distribution in cells and the dependence of their frequency on the harvesting point for various mutagens. Poisson aberration distribution in cells for two-center mutagens was found to correspond to their constant frequency observed at different times of harvesting. On the other hand, for one-center mutagens, a geometrical distribution of chromosome breaks corresponded to an exponential decrease in their frequency in time. It is suggested that two-center chemical mutagens and ionizing radiation cause largely short-live damages which are realized into chromosome aberrations rather quickly (during one cell cycle). One-center mutagens, however, cause such damages that the probability of their transformation into chromosome aberrations is decreasing rather slowly in time, under the exponential law, and their realization into chromosome aberrations can occur in subsequent cell cycle. PMID:2258036

  19. Painting Analysis of Chromosome Aberrations Induced by Energetic Heavy Ions in Human Cells

    Science.gov (United States)

    Wu, Honglu; Hada, Megumi; Cucinotta, Francis

    2007-01-01

    This viewgraph presentation reviews some of the techniques used to analyze the damage done to chromosome from ion radiation. Fluorescence in situ hybridization (FISH), mFISH, mBAND, telomere and centromereprobes have been used to study chromosome aberrations induced in human cells exposed to low-and high-LET radiation in vitro. There is some comparison of the different results from the various techniques. The results of the study are summarized.

  20. Influence of DMSO on Carbon K ultrasoft X-rays induced chromosome aberrations in V79 Chinese hamster cells

    International Nuclear Information System (INIS)

    Ultrasoft X-rays have been shown to be very efficient in inducing chromosomal aberrations in mammalian cells. The present study was aimed to evaluate the modifying effects of DMSO (a potent scavenger of free radicals) on the frequencies of chromosome aberrations induced by soft X-rays. Confluent held G1 Chinese hamster cells (V79) were irradiated with Carbon K ultrasoft X-rays in the presence and absence of 1 M DMSO and frequencies of chromosome aberrations in the first division cells were determined. DMSO reduced the frequencies of exchange types of aberrations (dicentrics and centric rings) by a factor of 2.1-3.5. The results indicate that free radicals induced by ultrasoft X-rays contribute to a great extent to the induction of chromosome aberrations. The possible implications of these results in interpreting the mechanisms involved in the high efficiency of ultrasoft X-rays in the induction of chromosome aberrations are discussed.

  1. Influence of DMSO on Carbon K ultrasoft X-rays induced chromosome aberrations in V79 Chinese hamster cells

    Energy Technology Data Exchange (ETDEWEB)

    Natarajan, Adayapalam T., E-mail: natarajan@live.nl [University of Tuscia, Viterbo (Italy); Palitti, Fabrizio [University of Tuscia, Viterbo (Italy); Hill, Mark A. [CRUK/MRC Gray Institute for Radiation Oncology and Biology, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ (United Kingdom); MRC Radiation and Genome Stability Unit, Harwell, Oxfordshire OX11 0RD (United Kingdom); Stevens, David L. [MRC Radiation and Genome Stability Unit, Harwell, Oxfordshire OX11 0RD (United Kingdom); Ahnstroem, Gunnar [Department of Microbiology and Genetic Toxicology, Stockholm University, Stockholm (Sweden)

    2010-09-10

    Ultrasoft X-rays have been shown to be very efficient in inducing chromosomal aberrations in mammalian cells. The present study was aimed to evaluate the modifying effects of DMSO (a potent scavenger of free radicals) on the frequencies of chromosome aberrations induced by soft X-rays. Confluent held G1 Chinese hamster cells (V79) were irradiated with Carbon K ultrasoft X-rays in the presence and absence of 1 M DMSO and frequencies of chromosome aberrations in the first division cells were determined. DMSO reduced the frequencies of exchange types of aberrations (dicentrics and centric rings) by a factor of 2.1-3.5. The results indicate that free radicals induced by ultrasoft X-rays contribute to a great extent to the induction of chromosome aberrations. The possible implications of these results in interpreting the mechanisms involved in the high efficiency of ultrasoft X-rays in the induction of chromosome aberrations are discussed.

  2. Particle-induced chromosome aberrations and mutations: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, S. [Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany)

    1997-09-01

    This overview will focus on progress in chromosome and mutation studies achieved by the application of new techniques. Furthermore, recent relevant data on longterm genetic effects of densely ionizing radiation will be summarized. (orig./MG)

  3. Effects of hyperbaric oxygen (HBO) treatment on chromosome aberrations in peripheral lymphocytes in rabbits induced by γ-ray irradiation

    International Nuclear Information System (INIS)

    Effect of hyperbaric oxygen (HBO) treatment on chromosome aberrations in peripheral lymphocytes in rabbits induced by 60Co γ-rays irradiation were studied. It was found that there is no effect of HBO itself on chromosomes in peripheral lymphocytes, and definite promotion effect of HBO treatment on recovery of chromosome damage in preipheral lymphocytes in rabbits induced by irradiation

  4. Cosmic radiation induced chromosomal aberrations in human lymphocytes

    International Nuclear Information System (INIS)

    Since decades, elevated frequencies of dicentric chromosomes (DIC) in human lymphocytes have successfully been used as a biological dosimeter in cases of acute, often accidental exposures to ionizing radiation. As long as duration and time lags after exposure are small compared to the lifetime of DIC, their frequencies can also be used to assess doses from protracted, chronic irradiation. E.g., within the substantial range of uncertainties, the frequencies of DIC observed in cosmonauts are compatible with the frequencies expected from doses of low and high LET radiation to which they were exposed in low earth orbit (LEO). On the other hand, frequencies of DIC detected in lymphocytes of civilian aviation crewmembers rarely correlate with the doses accumulated all along their professional career. For such long duration exposures with relatively low induction rates, the concomitant decay of DIC frequencies due to the removal during exposure of lymphocytes carrying DIC has to be taken into account. We present temporal profiles of frequencies of DIC during the exposure calculated with a model of exponential decay of DIC for some scenarios of chronic exposure to cosmic radiation. E.g., even after a 'heavily' shielded Mars mission, the expected frequencies of DIC in lymphocytes of astronauts will be 10 to 40 times higher than the terrestrial control levels. For air flight personnel we calculated the time profiles of frequencies of DIC in lymphocytes of a 'typical' pilot, a male cabin attendant and a female cabin attendant whose professional radiation exposures were recalculated for the actual flight routes flown during their entire flight career as recorded in detailed duty logs. These results demonstrate that experimental (epidemiological) studies concerning DIC in air or space flight personnel must explicitly take into consideration the temporal exposure profiles in the prospective study population and that the point in time at which blood samples are to be drawn must

  5. Chromosome aberrations induced in human lymphocytes by U-235 fission neutrons. Pt. 1

    International Nuclear Information System (INIS)

    A set-up for irradiation of biological samples in the TRIGA Mark II research reactor in Ljubljana is described. Threshold activation detectors were used for characterisation of the neutron flux, and the accompanying gamma dose was measured by TLDs. Human peripheral blood samples were irradiated 'in vitro' and biological effects evaluated according to the unstable chromosomal aberrations induced. Biological effects of two types of cultivation of irradiated blood samples, the first immediately after irradiation and the second after 96 h storage, were studied. A significant difference in the incidence of chromosomal aberrations between these two types of samples was obtained, while our dose-response curve fitting coefficients are in both cases lower than could be found in the literature. (orig./MG)

  6. Radiation-induced chromosome aberrations in cell populations from rat tracheal epithelium

    International Nuclear Information System (INIS)

    To determine cells at risk in the respiratory tract for the induction of cancer, it is essential to know not only the dose of toxic agent to the cells but also the sensitivity of each cell type to the agent. The purpose of this study is to define the radiation sensitivity of cells in the airway epithelium of the rat as the first step in determining the cells at risk for cancer induction by radiation. Tracheal epithelial cells were isolated, sorted by flow cytometry, grown in defined medium and exposed to graded doses of X rays. Survival and the frequency of chromosome aberrations were determined in the total cell population, in the sorted secretary and in the sorted basal cells. There was no difference in radiation-induced cytotoxicity of each cell type. The frequency of chromosome aberrations was determined by linear regression analysis and found to be 0.37 ± 0.01 aberrations/cell/Gy for the unsorted cells and 0.26 ± 0.02 for the sorted secretary cells. Because of the low number and cloning efficiency of basal cells, no data on X-ray-induced chromosome aberrations in these cells is available at the present time. There was a linear decrease in the chromatid-type aberration frequency as a function of time after the radiation exposure. The data suggest that, in terms of radiation sensitivity, all three cell populations are very similar. Thus, if there are differences in the response to a toxic agent such as radon, the differences should reflect differences in radiation dose to the cells. (author)

  7. mBAND Analysis of Late Chromosome Aberrations in Human Lymphocytes Induced by Gamma Rays and Fe Ions

    Science.gov (United States)

    Sunagawa, Mayumi; Zhang, Ye; Yeshitla, Samrawit; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2014-01-01

    Chromosomal translocations and inversions are considered stable, and cells containing these types of chromosome aberrations can survive multiple cell divisions. An efficient method to detect an inversion is multi-color banding fluorescent in situ hybridization (mBAND) which allows identification of both inter- and intrachromosome aberrations simultaneously. Post irradiation, chromosome aberrations may also arise after multiple cell divisions as a result of genomic instability. To investigate the stable or late-arising chromosome aberrations induced after radiation exposure, we exposed human lymphocytes to gamma rays and Fe ions ex vivo, and cultured the cells for multiple generations. Chromosome aberrations were analyzed in cells collected at first mitosis and at several time intervals during the culture period post irradiation. With gamma irradiation, about half of the damages observed at first mitosis remained after 7 day- and 14 day- culture, suggesting the transmissibility of damages to the surviving progeny. Detailed analysis of chromosome break ends participating in exchanges revealed a greater fraction of break ends involved in intrachromosome aberrations in the 7- and 14-day samples in comparison to the fraction at first mitosis. In particular, simple inversions were found at 7 and 14 days, but not at the first mitosis, suggesting that some of the aberrations might be formed days post irradiation. In contrast, at the doses that produced similar frequencies of gamma-induced chromosome aberrations as observed at first mitosis, a significantly lower yield of aberrations remained at the same population doublings after Fe ion exposure. At these equitoxic doses, more complex type aberrations were observed for Fe ions, indicating that Fe ion-induced initial chromosome damages are more severe and may lead to cell death. Comparison between low and high doses of Fe ion irradiation in the induction of late damages will also be discussed.

  8. Drinking beer reduces radiation-induced chromosome aberrations in human lymphocytes

    International Nuclear Information System (INIS)

    We here investigated and reported the effects of beer drinking on radiation-induced chromosome aberrations in blood lymphocytes. Human blood that was collected either before or after drinking a 700 ml beer was in vitro irradiated with 200 kVp X rays or 50 keV/μm carbon ions. The relation between the radiation dose and the aberration frequencies (fragments and dicentrics) was significantly (P<0.05) lower for lymphocytes collected 3 h after beer drinking than those before drinking. Fitting the dose response to a linear quadratic model showed that the alpha term of carbon ions was significantly (P<0.05) decreased by beer drinking. A decrease of dicentric formation was detected as early as 0.5 h after beer drinking, and lasted not shorter than 4.5 h. The mitotic index of lymphocytes was higher after beer drinking than before, indicating that a division delay would not be responsible for the low aberrations induced by beer drinking. An in vitro treatment of normal lymphocytes with 0.1 M ethanol, which corresponded to a concentration of 6-times higher than the maximum ethanol concentration in the blood after beer drinking, reduced the dicentric formation caused by X-ray irradiation, but not by carbon-ion irradiation. The beer-induced reduction of dicentric formation was not affected by serum. It is concluded that beer could contain non-ethanol elements that reduce the chromosome damage of lymphocytes induced by high-LET radiation. (author)

  9. Studies on chromosome aberrations induced in human lymphocytes by very low-dose exposure to tritium

    International Nuclear Information System (INIS)

    Assessment of potential hazard from environmental tritium to man becomes very important with increasing the development of nuclear-power industry. However, little data are available as to the determination on the genetic effect of tritium especially at the low levels. The object of the present study is to obtain quantitative data for chromosome aberrations in human lymphocytes, as an indicator for genetic risk estimation, induced by tritium at very low dose levels. Leukocyte cultures of human peripheral blood were chronically exposed for 48h to tritiated water and 3H-thymidine using a wide range of tritium doses, and aberrations in lymphocyte chromosomes at the first metaphases were examined. In the experimental conditions, the types of aberrations induced by radiation emitted from both tritiated water and 3H-thymidine were mostly chromatid types, such as chromatid gaps and deletions. The dose-response relations for chromatid breaks per cell exhibited unusual dose-dependency in both cases. It was demonstrated that at higher dose range the yields of chromatid breaks increased linearly with dose, while those at lower dose range were significantly higher than would be expected by a downward extraporation from the linear relation. Partial-hit or partial-target kinetics events appeared at very low dose exposure. (author)

  10. A comparison of chromosomal aberrations induced by in vivo radiotherapy in human sperm and lymphocytes

    International Nuclear Information System (INIS)

    Chromosomal aberrations in human sperm and lymphocytes were compared before and after in vivo radiation treatment of 13 cancer patients. The times of analyses after radiotherapy (RT) were 1, 3, 12, 24, 36, 48 and 60 months. The median total radiation dose was 30 Gy and the testicular dose varied from 0.4 to 5.0 Gy. Human sperm chromosome complements were analysed after fusion with golden hamster eggs. There were no abnormalities in sperm or lymphocytes before RT. Following RT there was an increase in the frequency of numerical and structural chromosomal abnormalities in both lymphocytes and sperm. For structural abnormalities there were more rejoined lesions (dicentrics, rings) in lymphocytes and more unrejoined lesions (chromosome breaks, fragments) in sperm. It appears that the frequency of lymphocyte chromosomal abnormalities had an initial marked increase after RT followed by a gradual decrease with time whereas the frequency of sperm chromosomal abnormalities was elevated when sperm production recovered and remained elevated from 24 to 60 mo. post-RT. This difference in the effect of time makes it very difficult to compare abnormality rates in lymphocytes and sperm and to use analysis of induced damage in somatic cells as surrogates for germ cells since the ratio between sperm and lymphocytes varied from 1:1 (at 24 mo. post-RT) to 5:1 (at 60 mo. post-RT). (author). 14 refs.; 2 figs.; 5 tabs

  11. High-LET Radiation Induced Chromosome Aberrations in Normal and Ataxia Telangiectasia Fibroblast Cells

    Science.gov (United States)

    Kawata, Tetsuya; George, Ms Kerry; Cucinotta, Francis A.; Shigematsu, Naoyuki; Ito, Hisao; Furusawa, Yoshiya; Uno, Takashi

    We investigated the effects of heavy ions beams on chromosomal aberrations in normal and AT cells. Normal and AT fibroblast cells arrested at G0/G1 phase were irradiated with 2 Gy of X-rays, 490 MeV/u Silicon (LET 55 keV/micron), 500 MeV/u Iron (LET 185 keV/micron) and 200 MeV/u Iron (LET 440 keV/micron) particles, and then cells were allowed to repair for 24 hours at 37 degrees before subculture. Calyculin-A induced PCC method was employed to collect G2/M chromosomes and whole DNA probes 1 and 3 were used to analyze chromosomal aberrations such as color-junctions, deletions, simple exchanges (incomplete and reciprocal exchanges) and complex-type exchanges. The percentages of aberrant cells were higher when normal and AT cells were exposed to heavy ions compared to X-rays, and had a tendency to increase with increasing LET up to 185 keV/micron and then decreased at 440 keV/micron. When the frequency of color-junctions per cell was compared after X-ray exposure, AT cells had around three times higher frequency of color-junctions (mis-rejoining) than normal cells. However, at 185 keV/micron there was no difference in the frequency of color-junctions between two cell lines. It was also found that the frequency of simple exchanges per cell was almost constant in AT cells regardless LET levels, but it was LET dependent for normal cells. Interestingly, the frequency of simple exchanges was higher for normal fibroblast cells when it was compared at 185 keV/micron, but AT cells had more complex-type exchanges at the same LET levels. Heavy ions are more efficient in inducing chromosome aberrations in normal and AT cells compared to X-rays, and the aberration types between normal and AT fibroblast appeared different probably due to difference in the ATM gene function.

  12. The role of DNA cluster damage and chromosome aberrations in radiation-induced cell killing: a theoretical approach

    International Nuclear Information System (INIS)

    The role played by DNA cluster damage and chromosome aberrations in radiation-induced cell killing was investigated, assuming that certain chromosome aberrations (dicentrics, rings and large deletions, or 'lethal aberrations') lead to clonogenic inactivation and that chromosome aberrations are due to micrometre-scale rejoining of chromosome fragments derived from DNA cluster lesions (CLs). The CL yield and the threshold distance governing fragment rejoining were left as model parameters. The model, implemented as a Monte Carlo code called BIANCA (Biophysical Analysis of Cell death and chromosome Aberrations), provided simulated survival curves that were compared with survival data on AG1522 and V79 cells exposed to different radiation types, including heavy ions. The agreement between simulation outcomes and experimental data suggests that lethal aberrations are likely to play an important role in cell killing not only for AG1522 cells exposed to X rays, as already reported by others, but also for other radiation types and other cells. Furthermore, the results are consistent with the hypothesis that the critical DNA lesions leading to cell death and chromosome aberrations are double-strand break clusters ( possibly involving the ∼1000- 10 000 bp scale) and that the effects of such clusters are modulated by micrometre-scale proximity effects during DNA damage processing. (authors)

  13. Micronuclei versus Chromosomal Aberrations Induced by X-Ray in Radiosensitive Mammalian Cells.

    Directory of Open Access Journals (Sweden)

    Cristina Plamadeala

    2015-03-01

    Full Text Available An experimental study was accomplished to compare estimation methods of ionizing radiations genotoxicity in mammalian cell cultures by means of two cytogenetic parameters with focus on aberrant cells characterized by multiple chromosomal damages.In vitro study was carried out on the genotoxicity of low-medium doses of 190 kV X-rays absorbed in Chinese hamster ovary cell cultures. Micronuclei and ten types of chromosomal aberrations were identified with Giemsa dying and optical microscope screening.The first parameter consisting in micronuclei relative frequency has led to higher linear correlation coefficient than the second one consistent with chromosomal aberrations relative frequency. However, the latter parameter estimated as the sum of all chromosomal aberrations appeared to be more sensitive to radiation dose increasing in the studied dose range, from 0 to 3 Gy. The number of micronuclei occurring simultaneously in a single cell was not higher than 3, while the number of chromosomal aberrations observed in the same cell reached the value of 5 for doses over 1 Gy.Polynomial dose-response curves were evidenced for cells with Ni micronuclei (i=1,3 while non-monotonic curves were evidenced through detailed analysis of aberrant cells with Ni chromosomal changes [Formula: see text] - in concordance with in vitro studies from literature. The investigation could be important for public health issues where micronucleus screening is routinely applied but also for research purposes where various chromosomal aberrations could be of particular interest.

  14. Chromosome painting analysis of radiation-induced aberrant cell clones in the mouse

    International Nuclear Information System (INIS)

    In a study of the persistence of radiation-induced translocations over the life span of the mouse, we observed a number of clonal cells in peripheral blood lymphocytes. The presence of clones caused the mean frequency of aberrations at various time points to be elevated which interfered with biodosimetry. For this reason, we have corrected our data for the presence of clones. Mice were given an acute dose of 0, 1, 2, 3 or 4 Gy 137Cs at 8 weeks of age. Aberrations were measured by painting chromosomes 2 and 8 and cells were examined for clones at 3 months and every 3 months thereafter until 21 months. Clones were identified by comparing the color photographic slides of all abnormal cells from each animal. Determination of clonality was made on the basis of similar breakpoint locations or the presence of other identifying characteristics such as unusual aberrations. To correct the frequency of translocations for the presence of clones, each clone, regardless of how many cells it contained, was counted only once. This reflects the original aberration frequency since each clone originated as only one cell. Among mice exposed to 4 Gy, the mean frequencies of aberrant cell clones ranged from 3-29% of the total number of metaphase cells scored with the highest frequency being 1 year post exposure. 32-70% of reciprocal and 19-92% of non-reciprocal translocations were clonal. A dose response relationship for clones was evident until 21 months when the unexposed animals exhibited a mean frequency of aberrant cell clones >10% of the total number of cells scored. Almost 75% of reciprocal and 95% of non-reciprocal translocations in these unexposed control animals were of clonal origin. Correction for clonal expansion greatly reduced the means and their standard errors at most time points where clonal expansion was prevalent. The biodosimetry was much improved suggesting that correction is beneficial in long-term studies

  15. The effect of x-ray induced mitotic delay on chromosome aberration yields in human lymphocytes

    International Nuclear Information System (INIS)

    The extent to which X-ray induced mitotic delay at 150 and 400 rad influences chromosome aberration yields was examined in human peripheral blood lymphocytes. The dicentric was used as a marker and aberration yields were obtained for mixed cultures prepared from equal numbers of normal and irradiated cells. The cultures were terminated following incubation times of 36-120 h. Greater mitotic delay of the order of a few hours was observed at the higher dose. However most reduction in the numbers of lymphocytes arriving at metaphase by 48 h may be ascribed to interphase death of failure to transform. Analysis of the dicentric distributions which were expected to follow Poisson statistics indicated that cells containing dicentrics were delayed relative to irradiated but aberration-free cells. Cells with one dicentric moved more easily through the first cell cycle than cells containing two dicentrics. Following accidental partial body irradiation, selection in culture favouring the unirradiated lymphocytes does not distort the aberration yield sufficiently to warrant incubation times in excess of the standard 48-52 h

  16. Heavy ion-induced chromosomal aberrations analyzed by fluorescence in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Durante, M.; Gialanella, G.; Grossi, G.; Pugliese, M. [Univ. ``Federico II``, Naples (Italy). Dept. of Physics]|[INFN, Naples (Italy); Cella, L.; Greco, O. [Univ. ``Federico II``, Naples (Italy). Dept. of Physics; Furusawa, Y. [NIRS, Chiba (Japan); George, K.; Yang, T.C. [NASA Lyndon B. Johnson Space Center, Houston, TX (United States)

    1997-09-01

    We have investigated the effectiveness of heavy ions in the induction of chromosomal aberrations in mammalian cells by the recent technique of fluorescence in situ hybridization (FISH) with whole-chromosome probes. FISH-painting was used both in metaphase and interphase (prematurely condensed) chromosomes. The purpose of our experiments was to address the following problems: (a) the ratio of different types of aberrations as a function of radiation quality (search for biomarkers); (b) the ratio between aberrations scored in interphase and metaphase as a function of radiation quality (role of apoptosis); (c) differences between cytogenetic effects produced by different ions at the same LET (role of track structure). (orig./MG)

  17. Effects of cryopreservation on the recovery of radiation-induced chromosome aberrations in human lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Littlefield, L.G.; Joiner, E.E.; Colyer, S.P.; Frome, E.L.

    1987-01-01

    Experiments were conducted to determine whether irradiated blood samples may be preserved by freezing without compromising the accurate assessment of radiation-induced chromosome aberrations in lymphocyte cultures initiated at later dates. Human whole blood at 37/sup 0/C was exposed in vitro to 0, 1, 2, or 4 Gy cobalt-60 gamma radiation, and lymphocytes were cultured immediately after exposure or after one weeks storage at -70/sup 0/C. A slight depression in cellular proliferation and a significant increase in chromatid breakages were observed in cultures initiated from the previously frozen lymphocytes. In preparations from both fresh and frozen lymphocytes the dose response relationships for radiation-induced dicentrics and acentrics were adequately described by the linear-quadratic dose response model (Y ..cap alpha..D + ..beta..D/sup 2/) with no significant differences in the values of the alpha or beta coefficients between the two sets of cultures. This finding provides evidence that lymphocytes bearing radiation-induced chromosome aberrations are not at selective risk for cell death as a result of cryopreservation.

  18. M-Band Analysis of Chromosome Aberrations in Human Epithelial Cells Induced By Low- and High-Let Radiations

    Science.gov (United States)

    Hada, M.; Gersey, B.; Saganti, P. B.; Wilkins, R.; Gonda, S. R.; Cucinotta, F. A.; Wu, H.

    2007-01-01

    Energetic primary and secondary particles pose a health risk to astronauts in extended ISS and future Lunar and Mars missions. High-LET radiation is much more effective than low-LET radiation in the induction of various biological effects, including cell inactivation, genetic mutations, cataracts and cancer. Most of these biological endpoints are closely correlated to chromosomal damage, which can be utilized as a biomarker for radiation insult. In this study, human epithelial cells were exposed in vitro to gamma rays, 1 GeV/nucleon Fe ions and secondary neutrons whose spectrum is similar to that measured inside the Space Station. Chromosomes were condensed using a premature chromosome condensation technique and chromosome aberrations were analyzed with the multi-color banding (mBAND) technique. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of both interchromosomal (translocation to unpainted chromosomes) and intrachromosomal aberrations (inversions and deletions within a single painted chromosome). Results of the study confirmed the observation of higher incidence of inversions for high-LET irradiation. However, detailed analysis of the inversion type revealed that all of the three radiation types in the study induced a low incidence of simple inversions. Half of the inversions observed in the low-LET irradiated samples were accompanied by other types of intrachromosome aberrations, but few inversions were accompanied by interchromosome aberrations. In contrast, Fe ions induced a significant fraction of inversions that involved complex rearrangements of both the inter- and intrachromosome exchanges.

  19. Effect of aspirin on chromosome aberration and DNA damage induced by X-rays in mice

    Science.gov (United States)

    Niikawa, M.; Chuuriki, K.; Shibuya, K.; Seo, M.; Nagase, H.

    In order to reveal the anticlastogenic potency of aspirin, we evaluated the suppressive ability of aspirin on chromosome aberrations induced by X-ray. Aspirin at doses of 0.5, 5 and 50 mg/kg was administrated intraperitoneally or orally at 0.5 h after or before the X-ray irradiation. The anticlastogenic activity of aspirin on chromosome aberrations induced by X-ray was determined in the mouse micronucleus test and alkaline single cell gel electrophoresis (SCG) assay in vivo. The frequency by polychromatic erythrocytes with micronuclei (MNPCEs) was decreased by about 19-61% at 0.5 h after and about 23-62% at 0.5 h before the X-ray irradiation. DNA damage by X-ray was significantly decreased by oral administration of aspirin at 0.5 h after or before the X-ray irradiation for the SCG assay. We consider aspirin can be used as preventive agents against exposure of X-ray.

  20. Radiation-induced chromosome aberrations and sister chromatid exchanges in lymphocytes from patients with tuberous sclerosis

    International Nuclear Information System (INIS)

    Lymphocytes from four patients with tuberous sclerosis (TS) and four normal controls were studied for sister chromatid exchanges (SCEs) and chromosome aberrations in gamma-ray irradiated cultures. There was no significant difference between SCE frequencies of TS lymphocytes and those of control lymphocytes at all doses examined (1, 2, and 4 Gy). However, chromosome aberrations in TS lymphocytes were significantly higher than those in the normal controls at the highest dose (4 Gy) (p < 0.05). (author)

  1. Proton and Fe Ion-Induced Early and Late Chromosome Aberrations in Different Cell Types

    Science.gov (United States)

    Wu, Honglu; Lu, Tao; Yeshitla, Samrawit; Zhang, Ye; Kadhim, Munira

    2016-01-01

    An early stage of cancer development is believed to be genomic instability (GI) which accelerates the mutation rate in the descendants of the cells surviving radiation exposure. To investigate GI induced by charged particles, we exposed human lymphocytes, human fibroblast cells, and human mammary epithelial cells to high energy protons and Fe ions. In addition, we also investigated GI in bone marrow cells isolated from CBA/CaH (CBA) and C57BL/6 (C57) mice, by analyzing cell survival and chromosome aberrations in the cells after multiple cell divisions. Results analyzed so far from the experiments indicated different sensitivities to charged particles between CBA/CaH (CBA) and C57BL/6 (C57) mouse strains, suggesting that there are two main types of response to irradiation: 1) responses associated with survival of damaged cells and 2) responses associated with the induction of non-clonal chromosomal instability in the surviving progeny of stem cells. Previously, we reported that the RBE for initial chromosome damages was high in human lymphocytes exposed to Fe ions. Our results with different cell types demonstrated different RBE values between different cell types and between early and late chromosomal damages. This study also attempts to offer an explanation for the varying RBE values for different cancer types.

  2. Identification of radiation-induced chromosome aberrations by G-band staining

    International Nuclear Information System (INIS)

    A comparative study was made concerning chromosome aberration, especially symmetrical aberration in 23 serious A-bomb survivors (exposed with more than 100 rad) based upon the observations by using an ordinary staining method (O-method) and a G-band staining method (G-method). By both staining methods, 548 cells of 896 which could be analyzed were identified as normal. Aberration was detected in remaining 348 cells by either method. The number of cells in which aberration was observed by G-method but not by O-method was 55. Cells where aberration was observed by O-method but not by G-method were only 6 in number. Concerning overall aberrations, there were 197 cells in which the number detected kind of aberration by both methods was inconsistent. Also there were 31 cells, aberration of which could not be identified by G-method. The number of cells identified as abnormal by G-method was 342 and 293 by O-method, namely identification of aberration by O-method was 86% of that by G-method. The kinds of aberration are now studying. Results obtained from this study were summarized as follows; aberration which could not be detected by O-method are frequently identified by G-method and most of these aberration are symmetrical. (Kanao, N.)

  3. Comparative studies of radiation-induced chromosome aberrations in several mammalian species

    International Nuclear Information System (INIS)

    The dose-response relationship for inducing chromosome aberrations in peripheral lymphocytes of five mammalian species - man, cynomolgus monkey, rabbit, domestic cat and beagle dog - were studied comparatively by whole-blood microculture technique following in-vitro exposures at various doses with 200-kVp X rays. The yields of induced chromosome aberrations were dependent on exposure doses between 48 and 480 rads in all the species examined. The relationship between exposure dose (D in rads) and frequency of induced dicentrics per cell (Y) was expressed by: Ysub((man)) = 14.38x10-6 Dsup(1.94); Ysub((monkey)) = 18.12x10-6 Dsup(1.86); Ysub((rabbit)) = 1.88x10-6 Dsup(2.06); Ysub((cat)) = 78.66x10-6 Dsup(1.35); Ysub((dog)) = 46.13x10-6 Dsup(1.37). Taking the frequency of dicentrics in man as 1.00, the relative frequency in each species was estimated as 0.79, 0.24, 0.22 and 0.16 in monkey, rabbit, cat and dog, respectively. From these results the consistent relationship could not be discovered between X-ray doses and the dicentric yield based on the arm number effect proposed by Brewen et al., whereas the nuclear DNA contents and the arm number in all the species used are roughly similar to those in man. The authors considered that such interspecies differences may be derived from the cellular and/or physiological features of PHA-responsible lymphocytes (T-cells) in each species, and that may be due to the level of development of each species on the phylogenetic or evolutionary scale. (author)

  4. A correlative study on the frequencies of radiation-induced chromosome aberrations in somatic and germ cells of mammals

    International Nuclear Information System (INIS)

    A series of investigations on the correlation between the frequencies of radiation-induced chromosome aberrations in somatic and germ cells of mouse and rhesus monkey is described. In the mouse the induction of reciprocal translocations in bone-marrow cells was compared with that in spermatogonia (as scored in the descending spermatocytes). In the rhesus monkey frequencies of radiation-induced chromosome aberrations in spermatogonia and peripheral blood lymphocytes were studied. Furthermore the effect of multigeneration irradiation (69 generations with 200 rads X-rays) on the sensitivity for translocation induction in spermatogonia of male mice was studied. Frequencies of dicentric chromosomes and chromosomal deletions in cultured peripheral blood lymphocytes of 5 different types of mice were determined following in vitro irradiation with doses of 100 and/or 200 rad X-rays. To obtain more insight into the processes underlying translocation induction in spermatogonia of the mouse, fractionation experiments were conducted

  5. Chromosomal aberrations induced by alpha particles; Aberraciones cromosomicas inducidas por particulas {alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Brena V, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: cgc@nuclear.inin.mx

    2005-07-01

    The chromosomal aberrations produced by the ionizing radiation are commonly used when it is necessary to establish the exposure dose of an individual, it is a study that is used like complement of the traditional physical systems and its application is only in cases in that there is doubt about what indicates the conventional dosimetry. The biological dosimetry is based on the frequency of aberrations in the chromosomes of the lymphocytes of the individual in study and the dose is calculated taking like reference to the dose-response curves previously generated In vitro. A case of apparent over-exposure to alpha particles to which is practiced analysis of chromosomal aberrations to settle down if in fact there was exposure and as much as possible, to determine the presumed dose is presented. (Author)

  6. Chromosome aberrations induced in human lymphocytes by U-235 fission neutrons. Pt. 2

    International Nuclear Information System (INIS)

    Blood samples were spiked with Na-24 to study the separate effect of this nuclide on the incidence of chromosomal aberrations in neutron irradiated blood samples. A delay of 96 h was allowed before cultivation, so the results of chromosomal aberration analysis could be compared with the results obtained by direct irradiation of blood samples with U-235 fission neutrons. The absorbed dose was calculated using a simple conservative model. From the results obtained we can conclude that Na-24 alone was not the reason for the difference in the incidence of chromosomal aberrations between blood samples cultivated immediately after 'in vitro' irradiation by U-235 fission neutrons and samples which were cultivated after 96 h storage. (orig.)

  7. The effect of caffeine posttreatment on X-ray-induced chromosomal aberrations in human blood lymphocytes in vitro

    International Nuclear Information System (INIS)

    The potentiating effect of caffeine on X-ray-induced chromosomal aberrations in human blood lymphocytes has been investigated, with special reference to cell cycle stages (G0 and G2). Both quantitative and qualitative differences in the yield of chromosomal aberrations were detected in caffeine-posttreated cells, depending on the cell stage irradiated. The studies on caffeine potentiating effects on X-irradiated G0 lymphocytes from normal adults, newborns, Down syndrome patients, and an ataxia telangiectasia patient pointed to interindividual variations in the response to caffeine potentiation among normal probands and a very profound effect in ataxia cells. (orig.)

  8. Zero-inflated regression models for radiation-induced chromosome aberration data: A comparative study.

    Science.gov (United States)

    Oliveira, María; Einbeck, Jochen; Higueras, Manuel; Ainsbury, Elizabeth; Puig, Pedro; Rothkamm, Kai

    2016-03-01

    Within the field of cytogenetic biodosimetry, Poisson regression is the classical approach for modeling the number of chromosome aberrations as a function of radiation dose. However, it is common to find data that exhibit overdispersion. In practice, the assumption of equidispersion may be violated due to unobserved heterogeneity in the cell population, which will render the variance of observed aberration counts larger than their mean, and/or the frequency of zero counts greater than expected for the Poisson distribution. This phenomenon is observable for both full- and partial-body exposure, but more pronounced for the latter. In this work, different methodologies for analyzing cytogenetic chromosomal aberrations datasets are compared, with special focus on zero-inflated Poisson and zero-inflated negative binomial models. A score test for testing for zero inflation in Poisson regression models under the identity link is also developed. PMID:26461836

  9. Chromosome aberration assays in Allium

    Energy Technology Data Exchange (ETDEWEB)

    Grant, W.F.

    1982-01-01

    The common onion (Allium cepa) is an excellent plant for the assay of chromosome aberrations after chemical treatment. Other species of Allium (A. cepa var. proliferum, A. carinatum, A. fistulosum and A. sativum) have also been used but to a much lesser extent. Protocols have been given for using root tips from either bulbs or seeds of Allium cepa to study the cytological end-points, such as chromosome breaks and exchanges, which follow the testing of chemicals in somatic cells. It is considered that both mitotic and meiotic end-points should be used to a greater extent in assaying the cytogenetic effects of a chemical. From a literature survey, 148 chemicals are tabulated that have been assayed in 164 Allium tests for their clastogenic effect. Of the 164 assays which have been carried out, 75 are reported as giving a positive reaction, 49 positive and with a dose response, 1 positive and temperature-related, 9 borderline positive, and 30 negative; 76% of the chemicals gave a definite positive response. It is proposed that the Allium test be included among those tests routinely used for assessing chromosomal damage induced by chemicals.

  10. Chromosome aberration analysis for biological dosimetry: a review

    International Nuclear Information System (INIS)

    Among various biological dosimetry techniques, dicentric chromosome aberration method appears to be the method of choice in analysing accidental radiation exposure in most of the laboratories. The major advantage of this method is its sensitivity as the number of dicentric chromosomes present in control population is too small and more importantly radiation induces mainly dicentric chromosome aberration among unstable aberration. This report brings out the historical development of various cytogenetic methods, the basic structure of DNA, chromosomes and different forms of chromosome aberrations. It also highlights the construction of dose-response curve for dicentric chromosome and its use in the estimation of radiation dose. (author)

  11. Chromosomal aberrations in the bone marrow cells of mice induced by accelerated {sup 12}C{sup 6+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Ma Xiaofei [Department of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang Hong, E-mail: zhangh@impac.ac.cn [Department of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Wang Zhenhua; Min Xianhua; Liu Yang; Wu Zhenhua [Department of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Sun Chao [Department of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Hu Bitao [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China)

    2011-11-01

    Highlights: {yields} 220 MeV/u {sup 12}C{sup 6+} ions is 1.5 times more effective than X-rays in inducing chromosomal aberration in bone marrow cell. {yields} The ratio of dose averaged liner energy transfer is approach the RBE. {yields} {sup 12}C{sup 6+} ions could induce severe mitosis delay. {yields} The cell cycle is not recovered 72 h following irradiation. - Abstract: The whole bodies of 6-week-old male Kun-Ming mice were exposed to different doses of {sup 12}C{sup 6+} ions or X-rays. Chromosomal aberrations of the bone marrow (gaps, terminal deletions and breaks, fragments, inter-chromosomal fusions and sister-chromatid union) were scored in metaphase 9 h after exposure, corresponding to cells exposed in the G{sub 2}-phase of the first mitosis cycle. Dose-response relationships for the frequency of chromosomal aberrations were plotted both by linear and linear-quadratic equations. The data showed that there was a dose-related increase in the frequency of chromosomal aberrations in all treated groups compared to controls. Linear-quadratic equations were a good fit for both radiation types. The compound theory of dual radiation action was applied to decipher the bigger curvature (D{sup 2}) of the dose-response curves of X-rays compared to those of {sup 12}C{sup 6+} ions. Different distributions of the five types of aberrations and different degrees of homogeneity were found between {sup 12}C{sup 6+} ion and X-ray irradiation and the possible underlying mechanism for these phenomena were analyzed according to the differences in the spatial energy deposition of both types of radiation.

  12. Reaction kinetics for the development of radiation-induced chromosome aberrations

    International Nuclear Information System (INIS)

    The formation of chromosome aberrations from DNA double-strand breaks (dsb) following ionizing irradiation of cells is analysed using a stochastic, continuous-time Markov chain formalism. A restitution/complete exchange model is proposed which incorporates kinetic competition between dsb restitution and chromosome exchange; it applies primarily to those dsb whose broken ends are held in close proximity by proteins. Some additional pathways for damage evolution are also considered. The calculations are compared in detail to the experiments on dicentric yield and variance in human lymphocytes following acute low-LET irradiation summarized by Lloyd and Edwards (1983) and Lloyd et al. (1987). (author)

  13. Chromosome Aberrations by Heavy Ions

    Science.gov (United States)

    Ballarini, Francesca; Ottolenghi, Andrea

    It is well known that mammalian cells exposed to ionizing radiation can show different types of chromosome aberrations (CAs) including dicentrics, translocations, rings, deletions and complex exchanges. Chromosome aberrations are a particularly relevant endpoint in radiobiology, because they play a fundamental role in the pathways leading either to cell death, or to cell conversion to malignancy. In particular, reciprocal translocations involving pairs of specific genes are strongly correlated (and probably also causally-related) with specific tumour types; a typical example is the BCR-ABL translocation for Chronic Myeloid Leukaemia. Furthermore, aberrations can be used for applications in biodosimetry and more generally as biomarkers of exposure and risk, that is the case for cancer patients monitored during Carbon-ion therapy and astronauts exposed to space radiation. Indeed hadron therapy and astronauts' exposure to space radiation represent two of the few scenarios where human beings can be exposed to heavy ions. After a brief introduction on the main general features of chromosome aberrations, in this work we will address key aspects of the current knowledge on chromosome aberration induction, both from an experimental and from a theoretical point of view. More specifically, in vitro data will be summarized and discussed, outlining important issues such as the role of interphase death/mitotic delay and that of complex-exchange scoring. Some available in vivo data on cancer patients and astronauts will be also reported, together with possible interpretation problems. Finally, two of the few available models of chromosome aberration induction by ionizing radiation (including heavy ions) will be described and compared, focusing on the different assumptions adopted by the authors and on how these models can deal with heavy ions.

  14. Aberrant Wnt/β-catenin signaling can induce chromosomal instability in colon cancer

    OpenAIRE

    Hadjihannas, Michel V; Brückner, Martina; Jerchow, Boris; Birchmeier, Walter; Dietmaier, Wolfgang; Behrens, Jürgen

    2006-01-01

    Chromosomal instability (CIN), a hallmark of most colon tumors, may promote tumor progression by increasing the rate of genetic aberrations. CIN is thought to arise as a consequence of improper mitosis and spindle checkpoint activity, but its molecular basis remains largely elusive. The majority of colon tumors develop because of mutations in the tumor suppressor APC that lead to Wnt/β-catenin signaling activation and subsequent transcription of target genes, including conductin/AXIN2. Here w...

  15. Studies on chromosomal aberrations and dominant lethal mutations induced by x irradiation in germ cells of male mice

    International Nuclear Information System (INIS)

    After male mice irradiated by 2 Gy X rays mated to normal virginal females superovulated with PMSG and HCG, pronuclei chromosome spreading of first-cleavage embryos were prepared and chromosomal aberrations of paternal pronuclei were observed. The results showed that the frequency of chromosomal aberrations was highest irradiated at spermatic stage among different stages of spermatogenesis. The sequence of radiosensitivity in spermatogenesis was as follows: spermatids > mature sperm > spermatocyte > spermatogonia and stem spermatogonia. The frequencies of paternal chromosomal aberrations resulted from irradiation at spermatids and mature sperms were significantly higher than that in control. The reciprocal translocations of stem spermatogonia induced by 2 Gy X rays in those male mice were also examined in the preparations of diakinesis-metaphase I. The frequency of reciprocal translocations were 0.0429 per cell and significantly higher than that in control. The proportion of unbalanced gametes, resulting in lethal embryos after fertilization, was 0.02145 to be predicted. At the same time, the dominant lethality induced by X rays in stem spermatogonia was measured, being 0.0371. The frequency of dead fetuses in irradiation group was about twice as in control. The regression analysis was found that the reciprocal translocations was markedly related to the dominant lethality

  16. Rapid detection of radiation-induced chromosomal aberrations in lymphocytes and hematopoietic progenitor cells by mFISH

    International Nuclear Information System (INIS)

    Structural chromosome aberrations (SCAs) are sensitive indicators of a preceding exposure of the hematopoietic system to ionizing radiation. Cytogenetic investigations have therefore become routine tools for an assessment of absorbed radiation doses and their biological effects after occupational exposure or radiation accidents. Due to its speed and ease of use, fluorescence in situ hybridization (FISH) with whole chromosome painting (WCP) probes has become a method of choice to visualize SCAs. Until recently, this technique was limited to a rather small number of chromosomes, which could be tested simultaneously. As a result, only a fraction of the structural aberrations present in a sample could be detected and the overall dose effect had to be calculated by extrapolation. The recent introduction of two genome-wide screening techniques in tumor research, i.e., Spectral Karyotyping (SKY) and multicolor FISH (mFISH) now allows the detection of translocations involving any two non-homologous chromosomes. The present study was prompted by our desire to bring the power of mFISH to bear for the rapid identification of radiation-induced SCAs. We chose two model systems to investigate the utility of mFISH: lymphocytes that were exposed in vitro to 3 Gy photons and single hematopoietic progenitor cell colonies isolated from a Chernobyl victim 9 years after in vivo exposure to 5.4 Sv. In lymphocytes, we found up to 15 different chromosomes involved in rearrangements indicating complex radiation effects. Stable aberrations detected in hematopoietic cell colonies, on the other hand, showed involvement of up to three different chromosomes. These results demonstrated that mFISH is a rapid and powerful approach to detect and characterize radiation-induced SCAs in the hemopoietic system. The application of mFISH is expected to result in a more detailed and, thus, more informative picture of radiation effects. Eventually, this technique will allow researchers to rapidly delineate

  17. Rapid detection of radiation-induced chromosomal aberrations in lymphocytes and hematopoietic progenitor cells by mFISH

    Energy Technology Data Exchange (ETDEWEB)

    Greulich, K.M.; Rhein, A.P.; Brueckner, M.; Molls, M. [Department of Radiation Oncology, Technical University of Munich, Ismaninger Strasse 22, D-81675 Munich (Germany); Kreja, L. [Institute for Occupational, Social and Environmental Medicine, University of Ulm, Ulm (Germany); Heinze, B. [Department of Medical Genetics, University of Ulm, Ulm (Germany); Weier, H.-U.G. [Life Sciences Division, E.O. Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Fuchs, P. [Vysis GmbH, Bergisch-Gladbach (Germany)

    2000-07-20

    Structural chromosome aberrations (SCAs) are sensitive indicators of a preceding exposure of the hematopoietic system to ionizing radiation. Cytogenetic investigations have therefore become routine tools for an assessment of absorbed radiation doses and their biological effects after occupational exposure or radiation accidents. Due to its speed and ease of use, fluorescence in situ hybridization (FISH) with whole chromosome painting (WCP) probes has become a method of choice to visualize SCAs. Until recently, this technique was limited to a rather small number of chromosomes, which could be tested simultaneously. As a result, only a fraction of the structural aberrations present in a sample could be detected and the overall dose effect had to be calculated by extrapolation. The recent introduction of two genome-wide screening techniques in tumor research, i.e., Spectral Karyotyping (SKY) and multicolor FISH (mFISH) now allows the detection of translocations involving any two non-homologous chromosomes. The present study was prompted by our desire to bring the power of mFISH to bear for the rapid identification of radiation-induced SCAs. We chose two model systems to investigate the utility of mFISH: lymphocytes that were exposed in vitro to 3 Gy photons and single hematopoietic progenitor cell colonies isolated from a Chernobyl victim 9 years after in vivo exposure to 5.4 Sv. In lymphocytes, we found up to 15 different chromosomes involved in rearrangements indicating complex radiation effects. Stable aberrations detected in hematopoietic cell colonies, on the other hand, showed involvement of up to three different chromosomes. These results demonstrated that mFISH is a rapid and powerful approach to detect and characterize radiation-induced SCAs in the hemopoietic system. The application of mFISH is expected to result in a more detailed and, thus, more informative picture of radiation effects. Eventually, this technique will allow researchers to rapidly delineate

  18. Chromosome aberrations induced by different kinds of radiation and their usefulness as biological indicator of the radiation damage

    International Nuclear Information System (INIS)

    Human lymphocytes were irradiated immediately after sample collection. The lymphocytes were cultured, according to the Hungerford micromethod, for 52 hours. Colcemid for mitotic arrest at the metaphase was added 4 hours prior to the end of the culture period. 220 KV x-rays at dose-rate of 60 rads/min in the dose range of 0,50, 100, 200, 300, 400 rads; Co-60 gamma-rays at dose-rate of 50 rads/min in the dose range 0,50, 100, 200, 300, 400 rads, and fission neutrons of different energies and flux densities (from the Experimental Nuclear Reactor IRT-2000 in Sofia) in the dose range 0,25, 50, 100, and 200 rads were used as sources. The following anomalies and parameters were analysed: chromatide and chromosome deletions, dicentrics and multicentrics, minutes, rings, total number of aberrations and total number of aberrant cells. The quantitative dose/anomaly relationship has been analysed by the least squares method using: Y=a+cD2, Y=a+bD, Y=bDsup(n), and Y=a+bD+cD2 as models where Y is the number of aberrations, D the dose in rads, and a,b,c,n, the equations coefficients. A functional relationship between the dose and the number of the structural chromosomal aberrations could be demonstrated. Low-LET radiations induced, by linear kinetics, chromosome deletions and increased the total number of aberrant cells and, by non-linear kinetics, the same induced dicentrics and multi-centrics, minutes, rings, and increased the total number of aberrations. Not all kinds of aberrations are fitted into the model Y=cD2. Two-break aberrations are best fitted into: Y=a+bD+cD2. High-LET radiations (e.g. fission neutrons) induced all kinds of aberrations according to Y=a+bD. The RBE values showed that Co-60 gamma radiation is 20% less effective than the 220 KV x-rays, and that RBE for fission neutrons varied from 1.8 at high doses to 5.0 at low doses

  19. Is 24-color FISH detection of in-vitro radiation-induced chromosomal aberrations suited to determine individual intrinsic radiosensitivity?

    International Nuclear Information System (INIS)

    Background: Reliable determination of intrinsic radiosensitivity in individual patients is a serious need in radiation oncology. Chromosomal aberrations are sensitive indicators of a previous exposure to ionizing irradiation. Former molecular cytogenetic studies showed that such aberrations as an equivalent of intrinsic radiosensitivity can be detected by fluorescence in-situ hybridization (FISH) techniques using whole chromosome painting (wcp) probes. However, only one up to three randomly chosen wcp probes have been applied for such approaches until now. As a random distribution of chromosomal rearrangements along the chromosomes is up to now still controversial, the power of the 24-color FISH approach should be elucidated in the present study. Methods and Material: Lymphocytes derived from lymphoblastoid cell lines of one patient with Nijmegen breakage syndrome (NBS homozygote) and of two NBS heterozygotes and peripheral blood lymphocytes of two controls were analyzed. Samples of each patient/control were irradiated in vitro with 0.0 Gy, 0.7 Gy or 2.0 Gy prior to cultivation. Chromosomal aberrations were analyzed in detail and quantified by means of 24-color FISH as an expression of the individual intrinsic radiosensitivity. Results: 24-color FISH analyses were done in a total of 1,674 metaphases. After in-vitro irradiation, 21% (0.7 Gy) or 57% (2.0 Gy) of the controls' cells, 15% (0.7 Gy) or 53% (2.0 Gy) of the heterozygotes' cells and 54% (0.7 Gy) or 79% (2.0 Gy) of the homozygote's cells contained aberrations. The highest average rates of breaks per mitosis [B/M] (0.7 Gy: 1.80 B/M, 2.0 Gy: 4.03 B/M) and complex chromosomal rearrangements [CCR] (0.7 Gy: 0.20 CCR/M, 2.0 Gy: 0.47 CCR/M) were observed in the NBS patient. Moreover, the proportion of different aberration types after irradiation showed a distinct increase in the rate of CCR combined with a decrease in dicentrics in the NBS homozygote. Conclusion: To come to a more complete picture of radiation-induced

  20. Chromosomal aberrations induced in mice bone marrow by treating with cisplatin and irradiation

    International Nuclear Information System (INIS)

    Background: The aim of this study was to quantify the combined effect of cisplatin and radiation on chromosomal damage with emphasis on the time interval between cisplatin and radiation. Methods and materials: Bone marrow of female NMRI-nu(+)mice was taken as a model system for a highly proliferative tissue irradiated with cobalt-60 (1 to 4 Gy). Cisplatin was injected intraperitoneally (ip) at 1.1 to 36 mg/kg. Cisplatin was given at various time intervals before and after radiation. Bone marrow and metaphases were prepared according to standard procedures. Results: The percentage of aberrant metaphases after radiation or cisplatin alone increased in a dose-dependent manner (sigmoidal dose-response curve). Combining both modalities led to additive values at all time points for the percentage of aberrant metaphases. Borderline significant (p<0.05) supraadditive effects were found 2 hours before or 1 hour after irradiation. However, a supraadditive percentage of aberrant chromosomes was found only at 2 or 1.5 hours with cisplatin before irradiation indicating the dependence of supraadditivity on the chosen parameter. Conclusion: It is doubtful to expect a true supraadditive or 'radiosensitizing' effect, e.g. in the clinical setting from combined treatment with cisplatin and radiation. Rather, cisplatin might act as an independent cytotoxic agent. (orig.)

  1. Prevention of radiation-induced chromosomal aberrations in bone marrow of mice by Indian medicinal plant, Alstonia scholaris

    International Nuclear Information System (INIS)

    Full text: It is well established that ionizing radiation can damage biologically important macromolecules such as DNA via both direct and indirect mechanisms. Chromosomal aberrations are a measure of direct effects on the genetic material and serve as useful biological dosimeter. With the realization of deleterious effects of ionizing radiation, a need was felt to protect human beings against these harmful effects by using physical and/or chemical means. Numerous chemical compounds have been tested for their ability to protect against ionizing radiation. Despite extensive screening of several synthetic compounds for radio protective activity, no single compound has emerged as a good radio protector so far. The plants have been the companion of man since time immemorial, providing several useful drugs for the treatment of various ailments. Therefore, it is natural that the choices of alternative radio protectors would include plants and plants products. However, some plants have been tested for radio protective action but a detailed study, with all possible end points, is still lacking. Hence, screening of natural products presents a major avenue for the discovery of new radioprotective drugs. Alstonia scholaris, a non toxic herbal preparation, has been reported to be clinically effective in treating syphilis insanity and epilepsy. A. scholaris has also been reported to inhibit liver injuries. These results encourage us to conduct further experiments to prove its radioprotective potential. The present study was performed to verify the radioprotective capacity of Alstonia scholaris on radiation-induced clastogenic change in term of chromosomal aberrations. For this purpose, one group of male Swiss albino mice was exposed to 5 Gy gamma radiation to serve as the control while the other group received Alstonia scholaris bark extract (100 mg/kg b. wt.) orally for 5 consecutive days before irradiation to serve as experimental. Such animals were pretreated with colchicine

  2. Chromosome aberrations induced in human lymphocytes by U-235 fission neutrons. Pt. 3. Evaluation of the effect of the induced α and β activity on the chromosomal aberration yield

    International Nuclear Information System (INIS)

    Aim: Further experiments were performed to explain a difference in chromosomal aberration yield found between samples cultivated immediately after fission neutron irradiation and samples which were cultivated with 96 h delay after irradiation. Material and Method: Human peripheral blood samples were irradiated in mixed fission neutron/gamma field (1800 s) and biological effect assessed in the mean of analysis of unstable chromosome aberrations with a time delay in culturing cells of 12, 24, 48 and 96 h. Additional measurements were performed on irradiated and blank blood samples with the aim to detect any increase in α and β activity after fission neutron irradiation. No difference was found. Results were compared to theoretically calculated values of the α and β activity released from natural radioactive isotopes. Result and Conclusion: As a conclusion it is shown that in our experimental conditions the secondary effects resulting from nuclear transformations of natural or induced radioactive isotopes, recoil reactions and accompanying α, β, and γ radiation are not the reason for the increase observed in chromosomal aberration yield in blood samples cultured with a time delay of at least 24 hours. (orig.)

  3. A model and code for the simulation of radiation-induced chromosome aberrations detectable with Giemsa or FISH

    International Nuclear Information System (INIS)

    Full text: A mechanistic model and a Monte Carlo code simulating the induction of chromosome aberrations by ionising radiation were developed. The model can predict dose-response curves for various types of aberrations (dicentrics, translocations, rings, complex exchanges and deletions) induced in human lymphocytes by gamma rays, protons and alpha particles of different energies. The model relies on the assumption that only clustered - and thus severe - DNA damage ('Complex Lesions', CL) can evolve into aberrations, and that only free-ends in neighbouring chromosomes can interact and form exchanges. The yields of CL induced by the various radiation types were taken from previous works; such lesions were distributed in the sphere representing the cell nucleus according to the radiation track structure. Interphase chromosome territories were explicitly simulated, allowing us to obtain final configurations in which each chromosome occupies an intra-nuclear domain with volume proportional to its DNA content. Accidental eurejoining was allowed. In order to reproduce experimental conditions as closely as possible, fragments smaller than 15 Mbp (Giemsa) or 11 Mbp (FISH) were neglected since they can hardly be detected in experiments. The presence of a background level of aberrations was also taken into account. Very good agreement was found with experimental dose-response curves taken from the literature, for both simple and complex exchanges. This provided a validation of the model both in terms of the adopted assumptions and in terms of the simulation techniques. The ratio of centric rings to dicentrics and of complex to simple exchanges was calculated as a function of the radiation type and energy. Such ratios were found to increase with the radiation LET, supporting the hypothesis that they can be good candidates as biomarkers of the radiation quality

  4. Radiation induced chromosome aberrations in somatic and germ cells of the male marmoset

    International Nuclear Information System (INIS)

    The induction of chromosome aberrations by low LET radiations was studied in peripheral lymphocytes and spermatogonial stem cells of the male marmoset. The data showed that there was no significant difference in the sensitivity of the lymphocytes whether they were irradiated in vitro or in vivo, but the frequency of heritable translocations recovered in the primary spermatocytes was considerably lower than that calculated to occur in the lymphocytes. The data are used to make estimates of human genetic risk from radiation based on limited interspecific comparisons

  5. Effect of smoking on the chromosome aberrations induced by environmental mutagens

    International Nuclear Information System (INIS)

    Chromosome aberration frequencies have increasingly been used for the study of various occupational and environmental exposures. Factors related to environmental in mutagens influence translocation yield. Smoking has impact on the translocation yield and is the most influential factor among the environmental mutagens to increase cancer incidence. In order to know how environmental mutagens affect the induction of translocations caused by smoking we analyzed translocations in the lymphocytes of smokers and nonsmokers in a large city, Beijing, a high natural background radiation area (HBRA) and in its control area (CA), remote villages in the south of China. The results of our analyses are reviewed in this presentation

  6. Baseline chromosome aberrations in children

    Czech Academy of Sciences Publication Activity Database

    Merlo, D.F.; Ceppi, M.; Stagi, E.; Bocchini, V.; Šrám, Radim; Rössner st., Pavel

    2007-01-01

    Roč. 172, - (2007), s. 60-67. ISSN 0378-4274 Grant ostatní: EU(EU) 2002-02198; EU(EU) 2005-016320 Institutional research plan: CEZ:AV0Z50390512 Source of funding: R - rámcový projekt EK ; R - rámcový projekt EK Keywords : chromosome aberrations * children * molecular epidemiology Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.826, year: 2007

  7. In-situ fluorescence hybridization applied to biological dosimetry: contribution of automation to the counting of radio-induced chromosome aberrations

    International Nuclear Information System (INIS)

    The frequency of chromosome aberrations on peripheral blood lymphocytes is a dose indicator in the case of ionizing radiations over-exposure. Stable chromosome aberrations (translocations, insertions) are visualized after labelling of some chromosomes using the fluorescence in-situ hybridization (FISH). The study of the use of the FISH technique in biological dosimetry is done with dose-effect curves. It seems that a bias is introduced during the observation of chromosome aberrations involving only 3 pairs of chromosomes. In order to avoid this bias, it would be useful to test the feasibility of using the multi-FISH technique in biological dosimetry. Moreover, this type of chromosome aberration changes with the type of irradiation. It is thus important to define the aberrations to be considered when the FISH technique is used. In order to reduce the time of image analysis, the CYTOGEN system, developed by IMSTAR company (Paris, France) has been adapted to the needs of biological dosimetry. This system allows to localize automatically the metaphases on the slide, which reduces the observation time by 2 or 4. An automatic detection protocol for chromosome aberrations has been implemented. It comprises the image capture, the contours detection and the classification of some chromosome aberrations. The different steps of this protocol have been tested in order to check that no bias is introduced by the automation. However, because radio-induced aberrations are rare events, it seems that a totally automatic system is not foreseeable. A semi-automatic analysis is more suitable. The use of the Slit-Scan technology (Laboratory of applied physics, Heidelberg, Germany) in biological dosimetry has been studied too. This technique allows to analyze rapidly a huge number of chromosomes. A good correlation has been observed between the dicentric frequency measured automatically and by manual counting. The system is under development and should be adapted to the detection of

  8. Chromosomal aberrations induced by Glycidol in Allium cepa L root meristem cells

    Directory of Open Access Journals (Sweden)

    N.Panneerselvam

    2012-02-01

    Full Text Available Glycidol is used as a stabilizer in the manufacture of vinyl polymers and natural oils and as an intermediate in the synthesis of glycerol, glycidyl ethers, and amines. It is also used as an alkylating agent,demulsifier, and dye-leveling agent and for sterilizing milk of magnesia. Glycidol is an alkylating agent which reacts readily with glutathione; it causes a decrease in glutathione content in rat liver, probably reflecting its binding to glutathione. It is a suspected reproductive toxicant and exposure to it has the potential to negatively affect the human reproductive system. The study investigated the cytotoxic effects of glycidol in Allium cepa L root meristem cells. Different concentrations of glycidol ranging 10, 20, 40 and 50μg/ml for 1, 2, 3 and 5h were treated with root meristem cells of Allium cepa L. Fuelgen squash technique was used to determine the aberrations in root tip cells. For each concentration 3000 well-spread cells were scored and cytological abnormalities such as break, gap, exchange, multiple breaks and chromosome fragments were observed. One way analysis of variance was used the study the significant different control and treatment exposed root tip cells.Significant difference between control and glycidol exposed cells were observed. Increasing concentrations increased the number of chromosomal aberrations.

  9. Chromosomal aberrations of blood lymphocytes induced in vitro by radon-222 daughter α-irradiation

    International Nuclear Information System (INIS)

    Blood samples were irradiated in vitro with α-rays emitted from short-lived radon decay products dissolved in the culture medium at doses between 0.03 and 41.4 mGy. The data were collected from experiments conducted during the period 1984-1992 and comprise a total of about 64000 scored metaphases. For statistical reasons, only 60,022 metaphases were used for the subsequent analysis. The results for total chromosome aberrations and dicentrics indicate a linear dose dependence in the dose range above about 10 mGy, consistent with other experimental observations. At doses below about 10 mGy, aberration frequencies cannot be linearly extrapolated from higher doses, suggesting that there is no dependence on dose within a certain low-dose range. In addition, a statistically significant minimum has been observed at a dose of about 0.03 mGy, which is consistently lower than the related control values. The behavior of the aberration frequencies in the low-dose region seems to be influenced by the control values, which also depend on the environmental radiation burdens to the donors before blood sampling and thus were significantly affected by the Chernobyl fallout

  10. Formation of radiation induced chromosome aberrations: involvement of telomeric sequences and telomerase

    International Nuclear Information System (INIS)

    As telomeres are crucial for chromosome integrity; we investigated the role played by telomeric sequences in the formation and in the transmission of radio-induced chromosome rearrangements in human cells. Starting from interstitial telomeric sequences (ITS) as putative region of breakage, we showed that the radiation sensitivity is not equally distributed along chromosomes and. is not affected by ITS. On the contrary, plasmid integration sites are prone to radio-induced breaks, suggesting a possible integration at sites already characterized by fragility. However plasmids do not preferentially insert at radio-induced breaks in human cells immortalized by telomerase. These cells showed remarkable karyotype stability even after irradiation, suggesting a role of telomerase in the genome maintenance despite functional telomeres. Finally, we showed that the presence of more breaks in a cell favors the repair, leading to an increase of transmissible rearrangements. (author)

  11. Formation of radiation induced chromosome aberrations: involvement of telomeric sequences and telomerase

    Energy Technology Data Exchange (ETDEWEB)

    Pirzio, L.

    2004-07-15

    As telomeres are crucial for chromosome integrity; we investigated the role played by telomeric sequences in the formation and in the transmission of radio-induced chromosome rearrangements in human cells. Starting from interstitial telomeric sequences (ITS) as putative region of breakage, we showed that the radiation sensitivity is not equally distributed along chromosomes and. is not affected by ITS. On the contrary, plasmid integration sites are prone to radio-induced breaks, suggesting a possible integration at sites already characterized by fragility. However plasmids do not preferentially insert at radio-induced breaks in human cells immortalized by telomerase. These cells showed remarkable karyotype stability even after irradiation, suggesting a role of telomerase in the genome maintenance despite functional telomeres. Finally, we showed that the presence of more breaks in a cell favors the repair, leading to an increase of transmissible rearrangements. (author)

  12. Mechanisms involved in the formation of mutagen-induced chromosome aberrations as determined by premature chromosome condensation

    International Nuclear Information System (INIS)

    In conventional studies of cytogenetic damage induced by mutagenic carcinogens, chromosomes are examined only when they become visible at metaphase, which often is many hours after exposure. Because many events can occur between the initial exposure and the final appearance of the damaged chromosomes at metaphase, the authors have now turned to the use of prematurely condensed chromosomes (PCCs) in which it is possible to observe interphase chromosomes shortly after exposure without allowing the cells to proceed to metaphase. Such a procedure, which eliminates the long delays between the introduction of the initial damage and its visualization, gives initial insights to the possible mechanisms involved in the production of genetic damage by mutagenic carcinogens. They used the method to study the effect of the pyrimidine nucleoside analogue cytosine arabinoside (ara-C), an inhibitor of DNA synthesis and chemotherapeutic agent that kills S phase cells and blocks the progression of cells from G1 into S phase. The authors now used a simple method for polyethylene-glycol-mediated cell fusion and PCC induction to analyze the effects of ara-C on G0 human lymphocytes. The PCC technique is a far more sensitive method for detecting damage than are the conventional metaphase techniques. Moreover, because only limited information is available on the repair of radiation damage in lymphocytes in the presence of DNA synthesis inhibitors, the technique was also used study the effect of ara-C on the repair of X-ray-induced chromosome breakage in unstimulated lymphocytes

  13. Body-weight and chromosome aberrations induced by X-rays in somatic cells of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Body-weight has been shown to influence the final expression of genetic damage by X-rays in Drosophila melanogaster. If larvae of Drosophila were raised up to the third instar in media containing different amounts of the same nutrient and in different conditions of crowding a positive correlation was observed between body-weight and frequency of chromosome aberrations induced by a given dose of X-rays in the somatic cells of their nerve ganglia. This effect, present in both sexes, is most plausibly attributed to a different capacity of big and small larvae for repairing radiation damage. (orig.)

  14. DNA Repair Defects and Chromosomal Aberrations

    Science.gov (United States)

    Hada, Megumi; George, K. A.; Huff, J. L.; Pluth, J. M.; Cucinotta, F. A.

    2009-01-01

    Yields of chromosome aberrations were assessed in cells deficient in DNA doublestrand break (DSB) repair, after exposure to acute or to low-dose-rate (0.018 Gy/hr) gamma rays or acute high LET iron nuclei. We studied several cell lines including fibroblasts deficient in ATM (ataxia telangiectasia mutated; product of the gene that is mutated in ataxia telangiectasia patients) or NBS (nibrin; product of the gene mutated in the Nijmegen breakage syndrome), and gliomablastoma cells that are proficient or lacking in DNA-dependent protein kinase (DNA-PK) activity. Chromosomes were analyzed using the fluorescence in situ hybridization (FISH) chromosome painting method in cells at the first division post irradiation, and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving >2 breaks in 2 or more chromosomes). Gamma irradiation induced greater yields of both simple and complex exchanges in the DSB repair-defective cells than in the normal cells. The quadratic dose-response terms for both simple and complex chromosome exchanges were significantly higher for the ATM- and NBS-deficient lines than for normal fibroblasts. However, in the NBS cells the linear dose-response term was significantly higher only for simple exchanges. The large increases in the quadratic dose-response terms in these repair-defective cell lines points the importance of the functions of ATM and NBS in chromatin modifications to facilitate correct DSB repair and minimize the formation of aberrations. The differences found between ATM- and NBS-deficient cells at low doses suggest that important questions should with regard to applying observations of radiation sensitivity at high dose to low-dose exposures. For aberrations induced by iron nuclei, regression models preferred purely linear dose responses for simple exchanges and quadratic dose responses for complex exchanges. Relative biological effectiveness (RBE) factors of all of

  15. Cadmium chloride strongly enhances cyclophosphamide-induced chromosome aberrations in mouse bone marrow cells

    Energy Technology Data Exchange (ETDEWEB)

    Pandurangarao, V.L.; Blazina, S.; Bherje, R. [Western Michigan Univ., Kalamazoo, MI (United States)] [and others

    1997-10-01

    Earlier we reported that a single 5 mg cadmium chloride (CdCl{sub 2})/kg ip dose enhanced chromosome aberrations (ca) with 50 mg/kg cyclophosphamide (CP) in mouse bone marrow cells. In this report groups of 4 mice were injected ip with saline, 0.31, 0.62, 1.25, 2.5 or 5.0 mg/kg CdCl{sub 2}, followed by saline injections at 24 h. Other mice similarly uninjected at 0 h were injected with 50 mg/kg CP at 24 h. All the mice were injected ip with 4 mg colchicine/kg at 44 h. At 48 h the bone marrow cells were processed for chromosome spreads. After dissection, visual examination revealed obvious internal hemorrhaging of the testes at 1.25 CdCl{sub 2} mg/kg and higher doses. This effect was not further increased by CP treatment. The lowest ca enhancing dose of CdCl{sub 2} on CP was 0.625 mg/kg. Our hypothesis is that Cd replaces zinc presents in numerous DNA repair enzymes and proteins resulting in diminished repair. Subsequently, the excess of unrepaired DNA damage is seen as chromatid breaks, deletions, fragments and exchanges.

  16. Chromosomal aberrations in ore miners of Slovakia

    International Nuclear Information System (INIS)

    A pilot study was performed in which the incidence of chromosomal aberrations in lymphocytes of miners in ore mines located in Central Slovakia was monitored and related to lifetime underground radon exposure and to lifetime smoking. The conclusions drawn from the results of the study were as follows: the counts of chromosomal aberrations in lymphocytes of miners were significantly higher than in an age matched control group of white-collar staff; the higher counts of chromosomal aberrations could be ascribed to underground exposure of miners and to smoking; a dependence of chromosomal aberration counts on the exposure to radon could not be assessed. (A.K.)

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

    Science.gov (United States)

    Elwej, Awatef; Ben Salah, Ghada; Kallel, Choumous; Fakhfakh, Faiza; Zeghal, Najiba; Ben Amara, Ibtissem

    2016-06-01

    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. PMID:26971618

  18. Dose effect relationship for chromosome aberrations induced in male mammalian germ cells

    International Nuclear Information System (INIS)

    The genetic effects of radiations on male germ cells and more specifically to type A spermatogonia which constitute the permanent population of the testes, were discussed. As exposure of spermatogonia does not cause a detectable increase in frequency of sex-chromosome loss only the problen of the induction of chromosome rearrangements, was studied. It was estimated that 5 rem of γ-irradiation given at a low dose-rate to spermagonia will produce 39 balanced translocations per million gametes and 78 unbalanced ones. Doubling the male rates will give 78 balanced translocations and 156 unbalanced translocations as the total estimate in a population of 1 million exposed to 5R of γ-irradiation at low dose rate. It must be pointed out that among normal humans the most common translocations are of Robertsonian type whereas the radiation induced translocation are of the reciprocal typ

  19. Chromosomal aberrations in ISS crew members

    Science.gov (United States)

    Johannes, Christian; Goedecke, Wolfgang; Antonopoulos, Alexandra

    2012-07-01

    High energy radiation is a major risk factor in manned space missions. Astronauts and cosmonauts are exposed to ionising radiations of cosmic and solar origin, while on the Earth's surface people are well protected by the atmosphere and a deflecting magnetic field. There are now data available describing the dose and the quality of ionising radiation on-board of the International Space Station (ISS). Nonetheless, the effect of increased radiation dose on mutation rates of ISS crew members are hard to predict. Therefore, direct measurements of mutation rates are required in order to better estimate the radiation risk for longer duration missions. The analysis of chromosomal aberrations in peripheral blood lymphocytes is a well established method to measure radiation-induced mutations. We present data of chromosome aberration analyses from lymphocyte metaphase spreads of ISS crew members participating in short term (10-14 days) or long term (around 6 months) missions. From each subject we received two blood samples. The first sample was drawn about 10 days before launch and a second one within 3 days after return from flight. From lymphocyte cultures metaphase plates were prepared on glass slides. Giemsa stained and in situ hybridised metaphases were scored for chromosome changes in pre-flight and post-flight blood samples and the mutation rates were compared. Results obtained in chromosomal studies on long-term flight crew members showed pronounced inter-individual differences in the response to elevated radiation levels. Overall slight but significant elevations of typical radiation induced aberrations, i.e., dicentric chromosomes and reciprocal translocations have been observed. Our data indicate no elevation of mutation rates due to short term stays on-board the ISS.

  20. Comparative studies on chromosome aberrations in rhesus monkeys induced by 60Co γ ray irradiation under different irradiation conditions

    International Nuclear Information System (INIS)

    Rhesus monkeys were irradiated by 60Cr γ ray exposure under different conditions, and comparative studies on their chromosome aberrations have been made. The dose rate of single acute irradiation was 223 mGy/min, the dose rate of fractionated curmulative irradiation was 223 mGy/min, and the dose of 0.25 Gy was delivered once a week, the dose rate of chronic continuous irradiation was 0.26 mGy/min for 190 min, 5 days per week. The total coumulative dose for each group was 2.0 Gy. It was found that the types of chromosome aberrations were mainly dicentric aberrations and acentric fragments in single acute irradiation, and acentric fragments in both fractionated coumulative and chronic continuous irradiation groups. The frequencies of chromosome aberrations in these groups increase linearly with increasing dose. The degree of chromosome damage in single acute irradiation group was much greater than those in the other groups, but degree and characteristics of chromosome damage between fractionated cumulative and chronic continuous irradiation groups was not significantly different. Acentric fragments in lymphocyte chromosomes ceased to increase when the cumulated dose in fractionated cumulative or chronic continuous irradiation reached to more than 1.0 Gy. The frequencies of chromosome aberrations basically decreased to control level within a year following the termination of irradiation

  1. Modulation of gamma ray induced chromosome aberrations in human peripheral blood lymphocytes by Hippophae rhammnoides leaf extract, SBL-1

    International Nuclear Information System (INIS)

    Hippophae rhammnoides L. commonly known as seabuckthorn is a temperate shrub and native of Asia and Europe. It has high antioxidant potential and is known to the traditional Indian, Chinese and Tibetan medicinal system for treatment of multiple disorders viz., circulatory and digestive disorders, hepatic injuries, neoplasia etc. One time treatment with the standardized leaf extract from H. rhammnoides (SBL-1) before whole body irradiation with 60Co (10 Gy), rendered more than 90% survival in non SBL-1 treated irradiated animals (J herbs, spices medi plants, 2009). Present study investigated the effects of SBL-1 treatment on chromosomal damage in human peripheral blood lymphocytes (PBL), with or without 60Co-gamma-radiation. The lymphocytes were isolated from the blood drawn from different donors. The isolated lymphocytes were divided into several groups: Group 1-untreated control, Group 2-irradiated (2 Gy), Group 3, 4 and 5 were treated with different concentration of SBL-1, 30 min. after irradiation with 60Co-gamma-rays (2 Gy). Group 6 was treated with the maximum concentration of SBL-1 used in the study. The metaphase spreading technique was used as per standard procedure to record chromosome breaks, dicentrics, acentrics and rings. The results were also recorded in terms of total aberrant metaphase and frequency of aberrant metaphase per 100 cells. In comparison to the untreated control, in the irradiated PBL culture, there was 8-fold increase in breaks, 211-folds in dicentrics, 75-folds in acentrics and 3-folds in rings (average data). SBL-1 alone at the highest concentration did not cause any significant change in number of breaks, dicentrics, acentrics and rings. The radiation induced aberrations decreased significantly by treatment with SBL-1 and the maximum decrease was observed when the cells were treated with 22μg/ml of SBL-1. These results demonstrated the anti-clastogenic activity of SBL-1 against gamma radiation induced damage. (author)

  2. In vitro radioprotective effects of histamine H2 receptor antagonists against gamma-rays induced chromosomal aberrations in human lymphocytes

    International Nuclear Information System (INIS)

    Background: Radioprotective capability of histamine H2 receptor antagonists have been shown in several in vivo studies mainly using animal models. However, to verify the effectiveness of these agents in clinical applications, studies should be performed on human lymphocytes using metaphase analysis. Materials and Methods: In vitro metaphase analysis technique was used to test the effects of cimetidine, ranitidine and famotidine on radiation induced clastogenic effects. Lymphocytes in whole peripheral blood were exposed to 3 Gy gamma-rays at a dose rate of 73.7 c Gy/min in the presence or absence of various doses of the drugs used in this study. The frequency of chromosomal aberrations were determined after standard metaphase preparations and staining slides in 5% Giemsa. Results: Results show that radiation produced a high number of chromosomal aberrations in lymphocytes compared to controls (p2-receptor antagonists used in this study effectively reduced the clastogenic effects of radiation with a dose reduction factor of 1.5-2 in human lymphocytes in vitro. The way in which these drugs reduce the clastogenic effects of radiation might be via radical scavenging mechanism

  3. Chromosomal induced aberrations in sunflower (Helianthus annuus L.) with gamma-irradiation, sodium azide and combined treatments

    International Nuclear Information System (INIS)

    The seeds of 2 varieties of common Sunflower (Helianthus annuus L.) viz: USH-430 and KL-675 were treated to estimate the mutagenicity of both gamma-rays, sodium azide alone and in combination with a view to generate morphological macro-mutations and screen and ascertain the chromosomal aberrations followed by reduction of pollen fertility with increased doses. An attempt was made to know the genetic basis of the chromosomal aberrations. Such aberrations are a source of changes in the pattern of gene regulation at the time of differentiation leading to the formation of cultivars. (author)

  4. Suppressing effect of antimutagenic flavorings on chromosome aberrations induced by UV-light or X-rays in cultured Chinese hamster cells

    International Nuclear Information System (INIS)

    Chromosome aberrations induces by UV-light or X-rays were suppressed by the post-treatment with antimutagenic flavorings, such as anisaldehyde, cinnamaldehyde, coumarin, and vanillin. UV- or X-ray-irradiated surviving cells increased in the presence of each flavouring. X-ray-induced breakage-type and exchange-type chromosome aberrations were suppressed by the vanillin treatment in the G1 phase of the cell cycle and a greater decrease in the number of X-ray-induced chromosome aberrations during G1 holding was observed in the presence of vanillin. Furthermore, a greater decrease in the number of X-ray-induced DNA single-strand breaks was observed in the presence of vanillin. Treatment with vanillin in the G2 phase suppressed UV-and X-ray-induced breakage-type but not exchange-type chromosome aberrations. The suppression of breakage-type aberrations was assumed to be due to a modification of the capability of the post-replicational repair of DNA double-strand breaks. (author). 28 refs.; 5 figs.; 6 tabs

  5. Photoreactivation of UV induced cell killing, chromosome aberrations, sister chromatide exchanges, mutations and pyrimidine dimers in Xenopus laevis fibroblasts

    International Nuclear Information System (INIS)

    Fibroblasts from Xenopus laevis, which posses photoreactivating enzyme were used to study the influence of photoreactivating light on the frequency of pyrimidine dimers in DNA, chromosomal aberrations, sister chromatid exchanges, cell killing and the induction of gene mutations (ouabain-resistance) induced by 254 nm ultraviolet irradiation. The frequency of all biological endpoints studied were reduced following exposure to photoreactivating light parallel to the reduction in the frequencies of pyrimidine dimers (determined as endonuclease sensitive sites). However, there was not always an absolute quantitative relationship between the reduction in the frequency of pyrimidine dimers and the reduction in the biological effects. This probably reflects a fast fixation process for the biological effects prior to removal of the dimers by photoreactivation. (orig.)

  6. Effect of taxol on chromosome aberrations induced by gamma radiation or by doxorubicin in Chinese hamster ovary cells

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    Francisca da Luz Dias

    1997-09-01

    Full Text Available Combined therapy with radiation and chemotherapy has being increasingly used in cancer treatment. The effect of combinations of taxol (0.08 mug/ml with doxorubicin (DXR, 0.5 or 1.0 mug/ml or gamma radiation (20 or 40 cGy was examined in two different treatment schedules (pretreatment or simultaneous treatment using Chinese hamster ovary (CHO cells treated at the G2 phase of the cell cycle. The results showed that taxol did not have a radiosensitizing effect on the chromosomal aberrations induced by gamma radiation nor did it have a potentiating effect on the chromosomal aberrations induced by DXR in CHO cells treated in the G2 phase of the cell cycleA terapia combinada com radiação e agentes químicos tem aumentado nos regimes de tratamento do câncer. Nesse estudo foi investigado o efeito das combinações de taxol (0,08 mig/ml com a doxorubicina (DXR 0,5 ou 1,0 mig/ml ou com as radiações gama (20 ou 40 cGy em dois diferentes protocolos de tratamento (pré-tratamento e simultâneo em células CHO tratadas na fase G2 do ciclo celular. Os resultados mostraram que o taxol não teve efeito sensibilizador sobre as aberrações cromossômicas induzidas pelas radiações gama, nem teve efeito potenciador sobre as aberrações cromossômicas induzidas pela DXR em células CHO tratadas na fase G2 do ciclo celular

  7. A comparative study of the frequencies of radiation-induced chromosome aberrations in somatic and germ cells of the Rhesus monkey (Macaca mulatta)

    International Nuclear Information System (INIS)

    Frequencies of radiation-induced chromosome aberrations in spermatogonia peripheral blood lymphocytes and bone-marrow cells of the rhesus monkey (Macaca mulatta) and in human blood lymphocytes, where determined at different exposures of X-rays. The dose-response curve for the induction of reciprocal translocations in spermatogonia suggested a 'hump' at about 200 rad. The absolute frequencies of chromosome aberrations in somatic and germ cells of the rhesus monkey were low in comparison with most other mammalian species and the ratio between aberrations in the two tissues was 25 to 1 at the 100 rad level. Although the numbers of 'effective chromosome arms' in man and rhesus monkey are similar (81 vs. 83), the rhesus monkey showed a lower rate of induction of dicentrics in blood lymphocytes than man at all doses reaching statistical significance at the 300 rad level

  8. MITOSIS ANA-THELOPHASE CHROMOSOMAL ABERRATIONS INDUCED BY UV IRRADIATION UNDER THE ANTIOXIDATIVE PROTECTION OF VITAMIN C, BY CALENDULA OFFICINALIS L.

    Directory of Open Access Journals (Sweden)

    Csilla Iuliana Bara

    2014-07-01

    Full Text Available due to the stratospheric ozone layer depletion, the researches focused in the last decades on the study of solarradiations reaching Earth surface. The target of the study was to establish the biological response of Calendula officinalisL. to UV irradiation, under the anti-oxidative protection of vitamin C, (which helps next to UV induced anti-oxidativeenzymes, in the protection against a large variety of products capable to induce free radicals formation.Our investigations were focused on detecting chromosomal aberrations which occurs during cells in division in meristemroot tips, under UV irradiation for 15 or 30 minutes, in the presence or absence of vitamin C, reported to the non-irradiated control samples. Regarding the mitotic index, it could be noticed an inhibition of cell division frequency underUV stress for all irradiated variants, not depending of presence or absence of vitamin C, positively correlated with theincrease of irradiation period. Maximal chromosomal aberrations frequency, were induced by UV radiations in the roottips of seedlings germinated in the absence of vitamin C, decreasing in the presence of vitamin C, due to the antioxidantprotective role of this. In the absence of UV irradiation, the chromosomal aberrations frequency was lower comparingwith irradiated variants, for all seedlings, even if germinated in the presence or absence of vitamin C. Betweenchromosomal aberrations were detected: bridges, expulsed and retardate chromosomes, fragments.

  9. Chromosomal aberrations and bone marrow toxicity.

    OpenAIRE

    Heddle, J A; Salamone, M F

    1981-01-01

    The importance of chromosomal aberrations as a proximate cause of bone marrow toxicity is discussed. Since chemicals that can cause nondisjunction are rare, numerical aberrations (aneuploidy, polyploidy) are not ordinarily important. Many structural aberrations, however, can lead directly to cell death and so are proximate causes of toxicity when they occur. The micronucleus test which utilizes the polychromatic erythrocyte is capable of detecting agents (clastogens) that can cause such struc...

  10. A comparative study on the frequencies of radiation-induced chromosome aberrations in the somatic and germ cells in mouse and monkey

    International Nuclear Information System (INIS)

    Two systems were mainly used for studying the relationship between radiation induced chromosome aberration frequencies in somatic and germ cells. The first consists of reciprocal translocation induced in bone-marrow cells of mice compared to reciprocal translocation induced spermatogonia (scored in descending spermatocytes) of the same mice. Dose-response curves for induced aberrations in both cell types (0-100-200-300-400-500 and 600 R X-rays) and dose rate effects indicated that (130-1.92-0.0287 R/min) of a 400 R γ-ray exposure of the two cell types mitotically dividing germ cells respond to radiation similarly to mitotic dividing germ cells. Clonal proliferation or selective elimination of aberration-carrying cells, and other post-irradiation factors can, however, cause great differences in absolute aberration frequencies. A similar study was attempted, using the rhesus monkey as a second system. Its bone-marrow cells were proved unsuitable for induced reciprocal translocations. Stimulated peripheral blood lymphocytes were studied instead. Following 100, 200 and 300 R of X-rays, the frequencies of induced dicentric chromosomes were compared to those of induced reciprocal translocations in spermatogonia. Human peripheral blood was studied similarly. It was concluded that: (a) The absolute frequencies of chromosome aberrations in somatic and germ cells of the rhesus monkey are low compared to most other mammalian species. (b) The ratio between dicentric frequencies and reciprocal translocation frequencies at 100 R and 200 R differed significantly from 4:1 reported for mouse and Chinese hamster and 2:1 for marmoset and man. (c) Although the numbers of 'effective chromosome arms' in man and rhesus monkey are similar (81 vs 83), the rhesus monkey showed at all doses a lower rate of induction of dicentrics in blood lymphocytes than man, reaching statistical significance at the 300 R level

  11. Biomarker for Space Radiation Risk: Painting Analysis of Chromosome Aberrations Induced by Energetic Heavy Ions in Human Cells

    Science.gov (United States)

    Hada, Megumi; George, Kerry; Cucinotta, Francis A.; Wu, Honglu

    2007-01-01

    Energetic heavy ions pose a great health risk to astronauts in extended ISS and future Lunar and Mars missions. High-LET heavy ions are particularly effective in causing various biological effects, including cell inactivation, genetic mutations, cataracts and cancer induction. Most of these biological endpoints are closely related to chromosomal damage, which can be utilized as a biomarker for radiation insults. Over the years, we have studied chromosomal damage in human fibroblast, epithelia and lymphocyte cells exposed in vitro to energetic charged particles generated at several accelerator facilities in the world. We have also studied chromosome aberrations in astronaut s peripheral blood lymphocytes before and after space flight. Various fluorescence in situ hybridization painting techniques have been used to identify from only the telomere region of the chromosome to every chromosome in a human cell. We will summarize the results of the investigations, and discuss the unique radiation signatures and biomarkers for space radiation exposure.

  12. Enhancement of chromosome aberrations induced in 5'-bromodeoxyuridine-labelled Chinese hamster ovary cells by monochromatic synchrotron radiations

    International Nuclear Information System (INIS)

    The chromosome study for the radiation-induced enhancement in producing various types of aberrations was conducted in a cultured cell line of CHO (Chinese hamster ovary) cells that were pre-labeled with BUdR (5'-deoxybromouridine) and irradiated by monochromatic X-rays with a slightly shorter wavelength (0.9 A) than the K adsorption edge of bromine (0.92 A). The dose-response changes in terms of frequencies of single-arm breaks and isochromatid breaks have shown that a maximum effect was produced by the combination of 0.9-A wavelength of X-irradiation and Br-incorporation and was above the magnitude of the so-called brome-induced sensitization obtained with 1.0-A wavelength X-rays. Such additional effect in the bromine-sensitized cells may be interpreted as the biological effect due to Auger electrons produced by photoelectric stimulation with 0.9-A monochromatic X-rays

  13. Biphasic Effects of Nitric Oxide Radicals on Radiation-Induced Lethality and Chromosome Aberrations in Human Lung Cancer Cells Carrying Different p53 Gene Status

    International Nuclear Information System (INIS)

    Purpose: The aim of this study was to clarify the effects of nitric oxide (NO) on radiation-induced cell killing and chromosome aberrations in two human lung cancer cell lines with a different p53 gene status. Methods and Materials: We used wild-type (wt) p53 and mutated (m) p53 cell lines that were derived from the human lung cancer H1299 cell line, which is p53 null. The wtp53 and mp53 cell lines were generated by transfection of the appropriate p53 constructs into the parental cells. Cells were pretreated with different concentrations of isosorbide dinitrate (ISDN) (an NO donor) and/or 2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) (an NO scavenger) and then exposed to X-rays. Cell survival, apoptosis, and chromosome aberrations were scored by use of a colony-forming assay, Hoechst 33342 staining assay and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP [deoxyuridine triphosphate] nick end labeling) assay, and chromosomal banding techniques, respectively. Results: In wtp53 cells the induction of radioresistance and the inhibition of apoptosis and chromosome aberrations were observed in the presence of ISDN at low 2- to 10-μmol/L concentrations before X-irradiation. The addition of c-PTIO and ISDN into the culture medium 6 h before irradiation almost completely suppressed these effects. However, at high concentrations of ISDN (100-500 μmol/L), clear evidence of radiosensitization, enhancement of apoptosis, and chromosome aberrations was detected. However, these phenomena were not observed in mp53 cells at either concentration range with ISDN. Conclusions: These results indicate that low and high concentrations of NO radicals can choreograph inverse radiosensitivity, apoptosis, and chromosome aberrations in human lung cancer cells and that NO radicals can affect the fate of wtp53 cells.

  14. Metaphase chromosome aberrations as markers of radiation exposure and dose

    International Nuclear Information System (INIS)

    Chromosome aberration frequency provides the most reliable biological marker of dose for detecting acute accidental radiation exposure. Significant radiation-induced changes in the frequency of chromosome aberrations can be detected at very low doses. Our paper provides information on using molecular chromosome probes ''paints'' to score chromosome damage and illustrates how technical advances make it possible to understand mechanisms involved during formation of chromosome aberrations. In animal studies chromosome aberrations provide a method to relate cellular damage to cellular dose. Using an In vivo/In vitro approach aberrations provided a biological marker of dose from radon progeny exposure which was used to convert WLM to dose in rat tracheal epithelial cells. Injection of Chinese hamsters with 144Ce which produced a low dose rate exposure of bone marrow to either low-LET radiation increased the sensitivity of the cells to subsequent external exposure to 60Co. These studies demonstrated the usefulness of chromosome damage as a biological marker of dose and cellular responsiveness

  15. Chromosome aberration yields in human lymphocytes induced by fractionated doses of x-radiation

    International Nuclear Information System (INIS)

    Unstimulated (G0) human peripheral blood lymphocytes were exposed at 37degC to doses of 200 or 500 rad of X-rays delivered in two equal fractions. The dose fractions were separated by intervals of up to 7 h in the 200 rad study and up to 48 h for 500 rad. In both studies the mean levels of dicentrics and total unstable aberrations began to decline when fractions were delivered with intervals of greater than 2 h. With 200 rad the yield had decreased to an additive baseline (i.e. equal to only twice the yield of a single 100-rad fraction) by an interval of 4 h. Following 500 rad the yield declined until 8 h and then remained 20% above the expected additive baseline even when 48 h separated the fractions. Possible explanations for this discrepancy are discussed. In a second experiment PHA stimulated lymphocyte cultures were exposed to 2 doses of 125 rad of X-rays up to 7 h apart in an attempt to demonstrate the late peak in aberration yield originally reported by Lane. Control cultures received unsplit doses of 250 rad at the time of the corresponding second 125-rad fraction. No evidence of a late peak in dicentric yield was observed. The yield remained approximately the same irrespective of the time interval between fractions but these split dose yields were significantly different from the accompanying unsplit controls

  16. Radiation-induced G2 delay and spontaneous chromosome aberrations in ataxia-telangiectasia homozygotes and heterozygotes

    International Nuclear Information System (INIS)

    The extent of cell cycle delay of lymphocytes X-irradiated in G2 phase was measured by mitotic inhibition determinations in 66 controls, 14 ataxia-telangiectasia (A-T) homozygotes and 27 obligate heterozygotes. Homozygotes had a significantly reduced mitotic index (MI) in unirradiated samples and showed significantly less radiation-induced mitotic inhibition than controls. This confirms our earlier disputed observations on A-T fibroblasts and demonstrates a G2 checkpoint defect in addition to the well-known defects in S phase and at the G1-S phase transition. There are two separate and opposite abnormal G2 responses of A-T cells; a primary event in which cells in G2 at the time of irradiation suffer less delay than controls, and a secondary event in which cells irradiated at earlier stages of the cycle are more delayed when they pass into G2. The MI of unirradiated heterozygote cells and the extent of mitotic inhibition were indistinguishable from controls. Spontaneous unstable chromosome aberrations were, as previously reported, significantly higher in homozygotes than in controls. (author)

  17. mBAND analysis of chromosome aberrations in human epithelial cells induced by gamma-rays and secondary neutrons of low dose rate.

    Science.gov (United States)

    Hada, M; Gersey, B; Saganti, P B; Wilkins, R; Cucinotta, F A; Wu, H

    2010-08-14

    Human risks from chronic exposures to both low- and high-LET radiation are of intensive research interest in recent years. In the present study, human epithelial cells were exposed in vitro to gamma-rays at a dose rate of 17 mGy/h or secondary neutrons of 25 mGy/h. The secondary neutrons have a broad energy spectrum that simulates the Earth's atmosphere at high altitude, as well as the environment inside spacecrafts like the Russian MIR station and the International Space Station (ISS). Chromosome aberrations in the exposed cells were analyzed using the multicolor banding in situ hybridization (mBAND) technique with chromosome 3 painted in 23 colored bands that allows identification of both inter- and intrachromosome exchanges including inversions. Comparison of present dose responses between gamma-rays and neutron irradiations for the fraction of cells with damaged chromosome 3 yielded a relative biological effectiveness (RBE) value of 26+/-4 for the secondary neutrons. Our results also revealed that secondary neutrons of low dose rate induced a higher fraction of intrachromosome exchanges than gamma-rays, but the fractions of inversions observed between these two radiation types were indistinguishable. Similar to the previous findings after acute radiation exposures, most of the inversions observed in the present study were accompanied by other aberrations. The fractions of complex type aberrations and of unrejoined chromosomal breakages were also found to be higher in the neutron-exposed cells than after gamma-rays. We further analyzed the location of the breaks involved in chromosome aberrations along chromosome 3, and observed hot spots after gamma-ray, but not neutron, exposures. PMID:20338263

  18. Frequency and distribution studies of asymmetrical versus symmetrical chromosome aberrations

    International Nuclear Information System (INIS)

    Two aspects of the relationship between Asymmetrical (A) and Symmetrical (S) radiation-induced chromosomal aberrations are considered in this paper. (1) Are A and S truly alternative modes of lesion interaction. Relative frequencies for chromatid-type and chromosome-type are examined, and new lymphocyte data using banding is used to look at this, and also for parallelism in chromosome participation of the two forms for various aberration categories. All the tests applied suggest that A and S are alternative interaction modes. (2) The long-term survival characteristics of A and S are discussed, and the differences in expected frequencies of derived S per surviving cell from chromosome-type and chromatid-types are stressed. Since many in vivo tissues have varying mixtures of potential chromatid and chromosome aberration-bearing target cells, ultimate cell survival and derived S frequencies may differ between tissues for the same absorbed dose. An Appendix gives Relative Corrected Lengths (RCL) for chromosomes of the human karyotype which should be used when testing the various exchange aberration categories for random chromosome participation. (orig.)

  19. Chromosomal aberrations induced by the restriction endonucleases Alu I and Bam HI: comparison with X-rays

    International Nuclear Information System (INIS)

    Dose-effect relationships for the frequencies of polycentric chromosomes induced by the restriction endonucleases Alu I and Bam HI and by X-rays in Chinese hamster ovary (CHO) cells were analyzed and compared. 1 Gy of X-rays produce the same frequency of polycentric chromosomes as 2 units Alu I and 7.9 units Bam HI. (author)

  20. Effects of turmeric and its active principle, curcumin, on bleomycin-induced chromosome aberrations in Chinese hamster ovary cells

    Directory of Open Access Journals (Sweden)

    Maria Cristina P. Araújo

    1999-09-01

    Full Text Available Naturally occurring antioxidants have been extensively studied for their capacity to protect organisms and cells from oxidative damage. Many plant constituents including turmeric and curcumin appear to be potent antimutagens and antioxidants. The effects of turmeric and curcumin on chromosomal aberration frequencies induced by the radiomimetic agent bleomycin (BLM were investigated in Chinese hamster ovary (CHO cells. Three concentrations of each drug, turmeric (100, 250 and 500 mg/ml and curcumin (2.5, 5 and 10 mg/ml, were combined with BLM (10 mg/ml in CHO cells treated during the G1/S, S or G2/S phases of the cell cycle. Neither turmeric nor curcumin prevented BLM-induced chromosomal damage in any phases of the cell cycle. Conversely, a potentiation of the clastogenicity of BLM by curcumin was clearly observed in cells treated during the S and G2/S phases. Curcumin was also clastogenic by itself at 10 µg/ml in two protocols used. However, the exact mechanism by which curcumin produced clastogenic and potentiating effects remains unknown.Antioxidantes de ocorrência natural têm sido exaustivamente estudados quanto a sua capacidade de proteger organimos e células contra danos oxidativos. Muitos constituintes das plantas, incluindo cúrcuma e curcumina, parecem ser potentes antimutágenos e antioxidantes. Os efeitos de cúrcuma e curcumina na freqüência de aberrações cromossômicas induzidas pelo agente radiomimético bleomicina (BLM foram investigados em células do ovário de hamster chinês (CHO. Três concentrações de cada droga, cúrcuma (100, 250 e 500 mg/ml e curcumina (2,5, 5,0 e 10 mg/ml, foram combinadas com BLM (10 mg/ml em células CHO tratadas durante as fases G1/S, S ou G2/S do ciclo celular. Nem cúrcuma nem curcumina evitaram o dano cromossômico induzido pela BLM em fase alguma do ciclo celular. Ao contrário, a potenciação da clastogenicidade da BLM pelo curcumina foi nitidamente observada em células tratadas

  1. Antimutagenic potential of curcumin on chromosomal aberrations in Allium cepa

    Institute of Scientific and Technical Information of China (English)

    RAGUNATHAN Irulappan; PANNEERSELVAM Natarajan

    2007-01-01

    Turmeric has long been used as a spice and food colouring agent in Asia. In the present investigation, the antimutagenic potential of curcumin was evaluated in Allium cepa root meristem cells. So far there is no report on the biological properties of curcumin in plant test systems. The root tip cells were treated with sodium azide at 200 and 300 μg/ml for 3 h and curcumin was given at 5, 10 and 20 μg/ml for 16 h, prior to sodium azide treatment. The tips were squashed after colchicine treatment and the cells were analyzed for chromosome aberration and mitotic index. Curcumin induces chromosomal aberration in Allium cepa root tip cells in an insignificant manner, when compared with untreated control. Sodium azide alone induces chromosomal aberrations significantly with increasing concentrations. The total number of aberrations was significantly reduced in root tip cells pretreated with curcumin. The study reveals that curcumin has antimutagenic potential against sodium azide induced chromosomal aberrations in Allium cepa root meristem cells. In addition, it showed mild cytotoxicity by reducing the percentage of mitotic index in all curcumin treated groups, but the mechanism of action remains unknown. The antimutagenic potential of curcumin is effective at 5 μg/ml in Allium cepa root meristem cells.

  2. Comparison of cell repair mechanisms by means of chromosomal aberration induced by proton and gamma irradiation - preliminary results

    Science.gov (United States)

    Kowalska, A.; Czerski, K.; Kaczmarski, M.; Lewocki, M.; Masojć, B.; Łukowiak, A.

    2015-03-01

    DNA damage of peripheral blood lymphocytes exposed to gamma and proton irradiation is studied by means of chromosome aberrations to validate the efficiency of the repair mechanisms of individual cells. A new method based on an observed deviation from the Poisson statistics of the chromosome aberration number is applied for estimation of a repair factor ( RF) defined as a ratio between originally damaged cells to the amount of finally observed aberrations. The repair factors are evaluated by studying the variance of individual damage factors in a collective of healthy persons at a given dose as well as by using the chi-square analysis for the dose-effect curves. The blood samples from fifteen donors have been irradiated by Co60 gamma rays and from nine persons by 150 MeV protons with different doses up to 2 Gy. A standard extraction of lymphocyte has been used whereby dicentrics, acentrics and rings have been scored under a microscope. The RF values determined for the proton radiation are slightly larger than for gamma rays, indicating that up to 70% DNA double strand breaks can be repaired.

  3. Chromosome aberrations induced in human lymphocytes by U-235 fission neutrons: I. Irradiation of human blood samples in the "dry cell" of the TRIGA Mark II nuclear reactor.

    Science.gov (United States)

    Fajgelj, A; Lakoski, A; Horvat, D; Remec, I; Skrk, J; Stegnar, P

    1991-11-01

    A set-up for irradiation of biological samples in the TRIGA Mark II research reactor in Ljubljana is described. Threshold activation detectors were used for characterisation of the neutron flux, and the accompanying gamma dose was measured by TLDs. Human peripheral blood samples were irradiated "in vitro" and biological effects evaluated according to the unstable chromosomal aberrations induced. Biological effects of two types of cultivation of irradiated blood samples, the first immediately after irradiation and the second after 96 h storage, were studied. A significant difference in the incidence of chromosomal aberrations between these two types of samples was obtained, while our dose-response curve fitting coefficients alpha 1 = (7.71 +/- 0.09) x 10(-2) Gy-1 (immediate cultivation) and alpha 2 = (11.03 +/- 0.08) x 10(-2) Gy-1 (96 h delayed cultivation) are in both cases lower than could be found in the literature. PMID:1962281

  4. Radiation-induced chromosomal aberrations in the lymphocytes of various species of mammals and the influence of coffeine during the G-2 phase

    International Nuclear Information System (INIS)

    The cellular kinetics and the G0-radiation sensitivity of human, chimpanzee, swine and rabbit lymphocytes were investigated using the lymphocytes test system (Ham's F-10 Medium, PHA). Due to the integration of BrdU in the DNA (S-phase), the author was able to distinguish between first, second and third mitoses (M1, M2, M3) in accordance with the differential colouring of the metaphase chromosomes which took place according to the labelling pattern. When checking the G0-radiation sensitivity of the lymphocytes, the rates of chromosomal aberrations in the metaphases of the first and second mitoses were evaluated separately. The different radiation sensitivities are thought to be due to interspecies differences in the repair capacity of the lymphocytes. In the metaphases of second mitoses, the rate of dicentric chromosomes is approximately half of that in M1-metaphases. Ring chromosomes were nearly as frequent in M2-metaphases as in M1-metaphases. In the second experimental phase, the effects of coffein on the aberration rates after radiation exposure of the lymphocytes in the G2 phase was investigated. Achromatic lesions, open chromatide breaks, and translocations were evaluated. Aberration rates were found to increase with the radiation dose and to decrease with the cultivation time after radiation exposure. There was no marked effect of coffein on the aberration rates. The progress of the G2 phase was measured in terms of the rate of radioactively labelled metaphases, which increased with the cultivation time. This labelling index was lower in the exposed cultures than in the control cultures, suggesting a radiation-induced delay of the G2 phase. The labelling indexes of all cultures were enhanced after coffein treatment, suggesting a coffein-induced acceleration of the G2 phase. (orig./MG)

  5. Simulations of DSB Yields and Radiation-induced Chromosomal Aberrations in Human Cells Based on the Stochastic Track Structure iIduced by HZE Particles

    Science.gov (United States)

    Ponomarev, Artem; Plante, Ianik; George, Kerry; Wu, Honglu

    2014-01-01

    The formation of double-strand breaks (DSBs) and chromosomal aberrations (CAs) is of great importance in radiation research and, specifically, in space applications. We are presenting a new particle track and DNA damage model, in which the particle stochastic track structure is combined with the random walk (RW) structure of chromosomes in a cell nucleus. The motivation for this effort stems from the fact that the model with the RW chromosomes, NASARTI (NASA radiation track image) previously relied on amorphous track structure, while the stochastic track structure model RITRACKS (Relativistic Ion Tracks) was focused on more microscopic targets than the entire genome. We have combined chromosomes simulated by RWs with stochastic track structure, which uses nanoscopic dose calculations performed with the Monte-Carlo simulation by RITRACKS in a voxelized space. The new simulations produce the number of DSBs as function of dose and particle fluence for high-energy particles, including iron, carbon and protons, using voxels of 20 nm dimension. The combined model also calculates yields of radiation-induced CAs and unrejoined chromosome breaks in normal and repair deficient cells. The joined computational model is calibrated using the relative frequencies and distributions of chromosomal aberrations reported in the literature. The model considers fractionated deposition of energy to approximate dose rates of the space flight environment. The joined model also predicts of the yields and sizes of translocations, dicentrics, rings, and more complex-type aberrations formed in the G0/G1 cell cycle phase during the first cell division after irradiation. We found that the main advantage of the joined model is our ability to simulate small doses: 0.05-0.5 Gy. At such low doses, the stochastic track structure proved to be indispensable, as the action of individual delta-rays becomes more important.

  6. Radiation-induced chromosome aberrations in ataxia telangiectasia cells: high frequency of deletions and misrejoining detected by fluorescence in situ hybridization

    Science.gov (United States)

    Kawata, Tetsuya; Ito, Hisao; George, Kerry; Wu, Honglu; Uno, Takashi; Isobe, Kouichi; Cucinotta, Francis A.

    2003-01-01

    The mechanisms underlying the hyper-radiosensitivity of AT cells were investigated by analyzing chromosome aberrations in the G(2) and M phases of the cell cycle using a combination of chemically induced premature chromosome condensation (PCC) and fluorescence in situ hybridization (FISH) with chromosome painting probes. Confluent cultures of normal fibroblast cells (AG1522) and fibroblast cells derived from an individual with AT (GM02052) were exposed to gamma rays and allowed to repair at 37 degrees C for 24 h. At doses that resulted in 10% survival, GM02052 cells were approximately five times more sensitive to gamma rays than AG1522 cells. For a given dose, GM02052 cells contained a much higher frequency of deletions and misrejoining than AG1522 cells. For both cell types, a good correlation was found between the percentage of aberrant cells and cell survival. The average number of color junctions, which represent the frequency of chromosome misrejoining, was also found to correlate well with survival. However, in a similar surviving population of GM02052 and AG1522 cells, induced by 1 Gy and 6 Gy, respectively, AG1522 cells contained four times more color junctions and half as many deletions as GM02052 cells. These results indicate that both repair deficiency and misrepair may be involved in the hyper-radiosensitivity of AT cells.

  7. Induction of chromosomal aberrations in human lymphocytes by fission neutrons

    International Nuclear Information System (INIS)

    Chromosome aberrations induced by sparsely ionizing radiation (low-LET) are well known and cytogenetic analyses of irradiated human lymphocytes have been widely applied to biological dosimetry. However, much less is known about chromosome aberrations induced by densely ionizing radiation (high LET), such as that of alpha particles or neutrons. Such particles induce DNA strand breaks, as well as chromosome breakage and rearrangements of high complexity. This damage is more localized and less efficiently repaired than after X- or γ-ray irradiation. This preferential production of complex aberrations by densely ionizing radiation is related to the unique energy deposition patterns, which produces highly localized multiple DNA damage at the chromosomal level. A better knowledge of the interactions between different types of radiation and cellular DNA is of importance, not only from the radiobiological viewpoint but also for dosimetric and therapeutic purposes. The objective of the present study was to analyse the cytogenetic effects of fission neutrons on peripheral blood lymphocytes in order to evaluate structural and numerical aberrations and number of cells in the different mitotic cycles. So, blood samples from five healthy donors, 22-25 years old, of both sexes, were irradiated in the Research Reactor IEA-R1 of our Institute (IPEN/CNEN-SP) with thermal and fast neutrons at doses of 0.2; 0.3; 0.5 and 1.0 Gy. The γ contribution to the total absorbed dose was about 30%. These doses were monitored by thermoluminescent dosemeters: LiF-600 (for neutrons) and LiF-700 (for γ-rays). The data concerning structural aberrations were evaluated with regard to three parameters: percentage of cells with aberrations, number of aberrations/cell and number of dicentric/cell. The cytogenetic results showed an increase in the three parameters after irradiation with neutrons, as a function of radiation dose. Apparently, there was no influence of neutrons on the kinetics of cellular

  8. A biological effectiveness study on chromosomal aberrations induced by fission neutrons versus 60Co γ-rays in human peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Objective: Whole blood lymphocytes samples being exposed to neutrons of 18 MeV energy and 60Co γ-rays respectively, both good dose-response relationships and relative biological effectiveness (RBE) were derived. Methods: Heparinized whole blood samples were exposed to neutrons and 60Co γ-rays, respectively. Radiation doses were from 0.5 Gy to 3.0 Gy. Dose rate was 0.2 Gy/min. Unstable chromosomal aberrations dicentrics and centric rings (dic+r), the same as Micronuclei in binucleated cells, were scored. Relative biological effectiveness (RBE) values of dic+rand Micronucleus were derived. Results: Chromosomal aberrations (dic+r) and Micronucleus induced by either neutrons or 60Co γ-rays had a good dose-response relationship. RBE value of chromosomal aberrations, exposed neutrons at 0.5-3.0 Gy, ranged from 1.59 to 2.81, similarly, micronucleus from 1.23 to 2.14. Conclusion: linear-quadratic dose-response was found for the induction of dic+r and Micronucleus in human lymphocytes exposed in vitro to neutrons of 18 MeV energy. neutrons has higher biological effectiveness in low doses. (authors)

  9. Studies on chromosome aberrations in workers occupationally exposed to radiation

    International Nuclear Information System (INIS)

    Cytogenetic assays for unstable chromosomes were performed on 54 medical radiation workers who are occupationally exposed to radiation and 42 controls. A total of 15,577 metaphase cells were scored. The frequencies of dicentrics and acentric chromosomes on controls were 0.52*10-3 and 0.82*10-2, respectively. On radiation workers those were 2.28*10-3 and 1.34*10-2, respectively. Though the frequencies of all types of chromosome aberrations in the workers were higher than those in the controls, the only significant difference was found in the case of dicentrics (P 0.05) except exposure dose of recent one year (P < 0.05). These results could indicate that low level exposure to ionizing radiation can induce unstable chromosome aberrations in blood lymphocytes

  10. Chromosome painting in biological dosimetry: Semi-automatic system to score stable chromosome aberrations

    International Nuclear Information System (INIS)

    From the beginning of the description of the procedure of chromosome painting by fluorescence in situ hybridization (FISH), it was thought its possible application to score induced chromosomal aberrations in radiation exposition. With chromosome painting it is possible to detect changes between chromosomes that has been validated in radiation exposition. Translocation scoring by FISH, contrarily to the unstable dicentrics, mainly detect stable chromosome aberrations that do not disappear, it allows the capability of quantify delayed acute expositions or chronic cumulative expositions. The large number of cells that have to be analyzed for high accuracy, specially when dealing with low radiation doses, makes it almost imperative to use an automatic analysis system. After validate translocation scoring by FISH in our, we have evaluated the ability and sensitivity to detect chromosomal aberrations by chromosome using different paint probes used, showing that any combination of paint probes can be used to score induced chromosomal aberrations. Our group has developed a FISH analysis that is currently being adapted for translocation scoring analysis. It includes systematic error correction and internal control probes. The performance tests carried out show that 9,000 cells can be analyzed in 10 hr. using a Sparc 4/370. Although with a faster computer, a higher throughput is expected, for large population screening or very low radiation doses, this performance still has to be improved. (author)

  11. Frequencies of X-ray induced chromosome aberrations in lymphocytes of xeroderma pigmentosum and Fanconi anemia patients estimated by Giemsa and fluorescence in situ hybridization staining techniques

    Directory of Open Access Journals (Sweden)

    Saraswathy Radha

    2000-01-01

    Full Text Available Blood lymphocytes from xeroderma pigmentosum (XP and Fanconi anemia (FA patients were assessed for their sensitivity to ionizing radiation by estimating the frequency of X-ray (1 and 2 Gy-induced chromosome aberrations (CA. The frequencies of aberrations in the whole genome were estimated in Giemsa-stained preparations of lymphocytes irradiated at G0 or G2 stages. The frequencies of translocations and dicentrics involving chromosomes 1 and 3 as well as the X-chromosome were determined in slides stained by fluorescence in situ hybridization (FISH technique. An increase in all types of CA was observed in XP and FA lymphocytes irradiated at G0 when compared to controls. The frequency of dicentrics and rings was 6 to 27% higher (at 1 and 2 Gy in XP lymphocytes and 37% higher (at 2 Gy in FA lymphocytes than in controls, while chromosome deletions were higher in irradiated (30% in 1 Gy and 72% in 2 Gy than in control XP lymphocytes and 28 to 102% higher in FA lymphocytes. In G2-irradiated lymphocytes the frequency of CA was 24 to 55% higher in XP lymphocytes than in controls. In most cases the translocation frequencies were higher than the frequencies of dicentrics (21/19.

  12. Modelling the formation of polycentric chromosome aberrations

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, R.K.; Tarver, J. (California Univ., Berkeley, CA (United States). Dept. of Mathematics); Yates, B.L.; Morgan, W.F. (California Univ., San Francisco, CA (United States))

    1992-10-01

    Exchange-type chromosome aberrations produced by ionizing radiation or restriction enzymes are believed to result from pairwise interaction of DNA double-strand breaks (dsb). In addition to dicentrics, such aberrations may include higher-order polycentries (tricentries, tetracentrics, etc.). The authors have developed computer programs that calculate the probability of the various polycentrics for a given average number of pairwise interactions. Two models are used. Model I incorporates kinetic competition between restitution, complete exchanges (illegitimate recombination events), and incomplete exchanges. Model II allows unrestituted breaks even if there is no recombination. The models were applied to experimental observations of aberrations produced in G[sub 1] Chinese hamster ovary cells after electroporation with the restriction enzyme PvuII, which produces blunt-end dsb. (author).

  13. Modelling the formation of polycentric chromosome aberrations

    International Nuclear Information System (INIS)

    Exchange-type chromosome aberrations produced by ionizing radiation or restriction enzymes are believed to result from pairwise interaction of DNA double-strand breaks (dsb). In addition to dicentrics, such aberrations may include higher-order polycentries (tricentries, tetracentrics, etc.). The authors have developed computer programs that calculate the probability of the various polycentrics for a given average number of pairwise interactions. Two models are used. Model I incorporates kinetic competition between restitution, complete exchanges (illegitimate recombination events), and incomplete exchanges. Model II allows unrestituted breaks even if there is no recombination. The models were applied to experimental observations of aberrations produced in G1 Chinese hamster ovary cells after electroporation with the restriction enzyme PvuII, which produces blunt-end dsb. (author)

  14. Relationships between DNA double-strand breaks and chromosomal aberrations

    International Nuclear Information System (INIS)

    Evidence suggests that double strand breaks are induced linearly with radiation dose at frequencies of 30-40 DSB/cell/Gy. It seems possible that there is a fast component not normally related to the induction of chromosomal aberrations, and a second slower component underlying the observed joining of chromosome and chromatid breaks. Radiation induces a mixture of blunt and cohesive-ended DSB probably with a preponderance of the latter which are much less effective at inducing aberrations. Visible chromatid breaks are also induced linearly with dose at much lower frequency than DSB and rejoin with a half-time reminiscent of slowly repairing DSB. It is possible that this slow rejoining reflects underlying repair of biologically important DSB. Rejoining of chromatid breaks and misjoining giving rise to exchanges are thought to be determined by different mechanisms. (UK)

  15. Dose-rate effect on chromosomal aberrations induced by 60Co γ-rays irradiation in human peripheral blood lymphocyte

    International Nuclear Information System (INIS)

    To estimate exactly the biological dose of persons exposed to different dose rate, human peripheral blood was exposed to 60Co γ-rays in vitro at low, middle and high dose rates respectively and chromosome samples were prepared, then dose-response curves were established according to the dicentrics and ring frequencies. The result showed that the aberration frequency at same dose level increased with dose rate and there was an obvious dose-rate effect. Absorbed dose estimated with low dose-rate dose-response curve was higher markedly than that with high dose-rate dose-response curve. So, considering the effect of dose-rate, approximate dose-rate dose-response curve should be chosen when absorbed dose estimation and the result will be credible. (authors)

  16. Dose-response of x-ray-induced anaphase aberrations in the mitotic root tip chromosomes of allium

    International Nuclear Information System (INIS)

    A simplified Allium root mitotic chromosome aberration assay by using only the aberrant anaphases (fragments, laggards and bridges) as the end-points were developed by Rank and Nielsen (1993) for screening water soluble chemicals and complex mixtures. A dose-response curve was established by Meir et al., (1994) using a known clastogen, 4-nitroquinolene-N-oxide between the dose range of 0.1-0.5 ug/ml. In order to further validate this assay for clastogen detection, a series of X-ray dose response experiments was carried out. Allium roots were germinated in tapwater for 48 h and treated with a series of 10, 20, 30, 40, 50, 60 R (80 Kvp, 5 ma, dose rate 60 R/min) dosages. After an 18 hr recovery time, the root tips were hydrolyzed in 45% acetic and 1 N HC1 acid (9:1 ratio) solution under 50 degrees C for 5 min and stained with aceto-carmine. Each of the data points were derived from scoring 7-10 slides (15-50 anaphases/slide). The corrrelation coefficient, slope and intercept values of the dose-response curve are: 0.954, 0.515 and 1.155 respectively

  17. Chromosome aberrations in A-bomb survivors, Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Radiation-induced chromosome rearrangements are known to have persisted in the peripheral blood lymphocytes of atomic bomb survivors in Hiroshima and Nagasaki. A dose-response relationship for chromosome aberration frequencies has been observed in both cities. A preliminary analysis of cytogenetic data indicates that the inter-city difference observed with the T65D dose estimate becomes less pronounced with the new DS86 dosimetry system. The regression coefficient of the dose-response curves is nevertheless higher in Hiroshima than in Nagasaki. The majority of chromosome aberrations detectable to date are of the stable type, such as translocations and inversions, and they have formed the dose-response relationship. (author)

  18. Use of the 5-bromodeoxyuridine-labelling technique for exploring mechanisms involved in the formation of chromosomal aberrations. Pt. 2

    International Nuclear Information System (INIS)

    Synchronized G1 CHO cells with chromosomes of TB or TT constitution were irradiated with X-rays, short-wave UV and long-wave UV. The types and frequencies of chromosomal aberrations observed in the ensuing mitosis were studied. X-Rays induced predominantly chromosome types of aberration in chromosomes of TT constitution, whereas both chromosome- and chromatid-types of aberration were induced in cells with chromosomes of TB constitution. Short-wave UV induced only chromatid types of aberration in cells containing chromosomes of TT constitution, but both chromosome and chromatid types of aberration in cells with chromosomes of TB constitution. Long-wave UV induced chromosome and chromatid types of aberration in cells with chromosomes of TB constitution and no aberrations in cells containing chromosomes of TT constitution. Long-wave UV-irradiation of cells containing chromosomes of TB constitution increases the frequencies of SCEs. The relationship between chromosome constitution (TT or TB), the type of lesions induced by the 3 different agents employed, and the types chromosomal aberration induced are discussed. (orig.)

  19. Radiotherapeutical chromosomal aberrations in laryngeal cancer patients

    Directory of Open Access Journals (Sweden)

    Stošić-Divjak Svetlana L.

    2009-01-01

    Full Text Available Introduction. The authors present the results of cytogenetic analysis of 21 patients with laryngeal carcinomas diagnosed and treated in the period 1995-2000 at the Institute of Otorhinolaryngology and Maxillofacial Surgery, Clinical Center of Serbia and Clinical Center of Novi Sad. Material and methods. The patients were specially monitored and the material was analyzed at the Institute of Human Genetics of the School of Medicine in Belgrade as well as in the Laboratory for Radiological Protection of the Institute of Occupational and Radiological Health 'Dr Dragomir Karajovic' in Belgrade. Results. The incidence of chromosomal aberrations and incidence of exchange of material between sister chromatids were observed in the preparation of the metaphasic lymphocyte chromosomes of the peripheral blood obtained in the culture. Structural aberrations were found on the chromosomes in the form of breakups, rings, translocations and dicentrics as early as after a single exposure of patients to tumor radiation dose of 2 Gy in the field sized 5x7. Out of the total number of 35 cultivated blood samples obtained from 13 patients, 21 were successfully cultivated and they were proved to contain chromosomal aberrations. Some of the peripheral blood samples failed to show cell growth in vitro due to the lethal cell damages in vivo. Discussion.. We have consluded that the number of structural aberrations cannot be used as a biological measure of the absorbed ionizing radiation dose. The presence of aberrations per se is indicative of the mutagenic effect of the ionizing radiation, which was also confirmed in our series on the original model by cultivation of the peripheral blood lymphocytes in the culture of the cells of the volunteer donors upon in vitro radiation. Using the method of bromdeoxyuridylreductase, the increased incidence of SCE as a mutagenic effect was registered. Conclusion. It has been concluded that the increase of absorbed radiation dose in

  20. Antimutagenic effects of garlic extract on chromosomal aberrations.

    Science.gov (United States)

    Shukla, Yogeshwer; Taneja, Pankaj

    2002-02-01

    Garlic (Allium sativum) has been used since ancient times, as a spice and also for its medicinal properties. In present set of investigations antimutagenic effect of garlic extract (GE) has been evaluated using 'in vivo chromosomal aberration assay' in Swiss albino mice. Cyclophosphamide (CP), a well-known mutagen, was given at a single dose of 25 mg/kg b.w. intraperitoneally. Pretreatment with 1, 2.5 and 5% of freshly prepared GE was given through oral intubation for 5 days prior to CP administration. Animals from all the groups were sacrificed at sampling times of 24 and 48 h and their bone marrow tissue was analyzed for chromosomal damage. The animals of the positive control group (CP alone) shows a significant increase in chromosomal aberrations both at 24 and 48 h sampling time. GE, alone did not significantly induced aberrations at either sampling time, confirming its non-mutagenicity. However in the GE pre-treated and CP post-treated groups, a dose dependent decrease in cytogenetic damage was recorded. A significant suppression in the chromosomal aberrations was recorded following pretreatment with 2.5 and 5% GE administration. The anticytotoxic effects of GE were also evident, as observed by significant increase in mitotic index, when compared to positive control group. Reduction in CP induced clastogenicity by GE was evident at 24 h and to a much greater extent at 48 h of cell cycle. Thus results of the present investigations revealed that GE has chemopreventive potential against CP induced chromosomal mutations in Swiss albino mice. PMID:11790451

  1. Use of chromosome aberrations for predicting genetic hazards to man

    International Nuclear Information System (INIS)

    The question of the use of chromosome aberrations for predicting genetic hazards to man is discussed under the following headings: interspecific comparisons of dicentric and deletion production in peripheral leukocytes; comparison of dicentric yields in leukocytes to reciprocal translocation yield in spermatogonia; recovery of spermatogonia induced translocations in the sons of irradiated males; cytologically and genetically detected deletions; and current gaps in our knowledge and problems of future interest

  2. Use of Chromosome Aberration Frequencies for Biological Dosimetry in Man

    International Nuclear Information System (INIS)

    The vast amount of work on chromosome aberrations induced by radiation exposure under defined biological and physical conditions, has shown that there exist strict relationships between aberration frequencies, radiation quality and absorbed dose in a variety of cell systems. These relationships are such that in many irradiated plant and animal systems the frequency of induced chromosome aberrations has been used to give reliable estimates of the radiation dose to which the system was exposed. A similar extrapolation from induced aberration frequency to absorbed dose can be made with human peripheral blood lymphocytes, if such cells are exposed and cultured in vitro under well defined conditions. Moreover, since aberrations induced in lymphocytes following an in vivo exposure can be detected in the cells when subsequently cultured in vitro, the peripheral blood leucocyte system has been utilized for biological dosimetry in cases where individuals have been accidentally exposed to radiations. In the case of uniform whole-body exposure of an individual, and under defined conditions of in vitro culture, the system may be expected to fulfil most of the requirements for a sensitive and accurate biological measure of absorbed dose. In this context biological variations between individuals may be of importance and the influence of such factors as age and genotype on the radiation response are considered. In cases of partial body exposure, there are a variety of biological factors that may have a considerable influence on the yields of aberrations measured in cells removed from the body shortly after exposure. Factors that are important include: the proportions of lymphocytes located in or passing through the radiation field at the time of exposure; the distribution and mobility of lymphocytes between peripheral blood and the lymphoid systems; differences in the radiation response of lymphocytes of differing types, and differences in the capacities of irradiated and non

  3. On the spontaneous frequency of the structural chromosome aberrations (anomalies) in lymphocytes from human blood

    International Nuclear Information System (INIS)

    Chromosomal aberrations are observed both in irradiated cells and in cells which have not been irradiated but submitted to the action of the natural radioactive background. The reasons for these ''spontaneous chromosomal aberrations'' are both the natural radioactivity and a complex of physical, chemical and biological factors. A cytogenetic analysis of 6000 lymphocytes metaphases from the peripheral blood of 47 people indicates that the overall amount of the spontaneous aberrations is 2% with a ratio of chromosomal type aberrations to chromatide type aberrations of 1:5. Chromatide type aberrations are seen as the result of purely mechanical factors acting during slides preparation but yet another unknown moments cannot be excluded. They are more one hit type aberrations - chromatide and chromosomal fragments, wereas the two hit aberrations are very rare - one dicentric per 3000 cells. The chromosome type aberrations are proposed for comparison with radiation induced aberrations in human lymphocytes. They have a frequency of 0.0035 per cell or 0.0040 breakages per cell. Ionizing radiation does not induce qualitatively specific type of aberrations but increases many times the yield of anomalies, which are spontaneously observed. (A.B.)

  4. Chromosome aberrations in ataxia telangiectasia cells exposed to heavy ions

    Science.gov (United States)

    Kawata, T.; Cucinotta, F.; George, K.; Wu, H.; Shigematsu, N.; Furusawa, Y.; Uno, T.; Isobe, K.; Ito, H.

    Understanding of biological effects of heavy ions is important to assess healt h risk in space. One of the most important issues may be to take into account individual susceptibility. Ataxia telangiectasia (A-T) cells are known to exhibit abnormal responses to radiations but the mechanism of hyper radiosensitivity of A-T still remains unknown. We report chromosome aberrations in normal human fibroblasts and AT fibroblasts exposed to low- and high-LET radiations. A chemical-induced premature chromosome condensation (PCC) technique combined with chromosome- painting technique was applied to score chromosome aberrations in G2/M-phase cells. Following gamma irradiation, GM02052 cells were approximately 5 times more sensitive to g-rays than AG1522 cells. GM02052 cells had a much higher frequency of deletions and misrejoining than AG1522 cells. When the frequency of complex type aberrations was compared, GM02052 cells showed more than 10 times higher frequency than AG1522 cells. The results will be compared with those obtained from high-LET irradiations.

  5. Monitoring of chromosomal aberrations in natural populations of Pinus pallasiana

    OpenAIRE

    V. P. Koba

    2012-01-01

    This paper presents the results of monitoring research of the chromosome aberrations at the stage of anaphase-telophase. The statistical characteristics of dynamics of chromosomal aberrations in populations of Pinus pallasiana D. Don across the high-altitude zones of the Mountain Crimea is given. It is established that on the southern macroslope of the Crimean Main Ridge the frequency of chromosomal aberrations in the P. pallasiana stands is higher in the lower zone in comparison with the mid...

  6. Chromosomal aberrations in children exposed to diagnostic x-rays

    International Nuclear Information System (INIS)

    Among children who have received high x-ray doses congenital dislocation of the hip joint is the predominating diagnosis. In a series of 9 children who had received high x-ray doses (8 with luxation of the hip joint and one with achondroplasia) a significant increase of chromosomal aberrations was found. The increase concerned mainly chromosome type aberrations. The shorter the time since the last x-ray investigation the higher was the frequency of chromosome type aberrations. (author)

  7. Pattern of Chromosomal Aberrations in Patients from North East Iran

    OpenAIRE

    Saeedeh Ghazaey; Farzaneh Mirzaei; Mitra Ahadian; Fatemeh Keifi; Semiramis Tootian; Mohammad Reza Abbaszadegan

    2013-01-01

    Objective: Chromosomal aberrations are common causes of multiple anomaly syndromes. Recurrent chromosomal aberrations have been identified by conventional cytogenetic methods used widely as one of the most important clinical diagnostic techniques. Materials and Methods: In this retrospective study, the incidences of chromosomal aberrations were evaluated in a six year period from 2005 to 2011 in Pardis Clinical and Genetics Laboratory on patients referred to from Mashhad and other cities in K...

  8. PARP inhibitor 3-aminobenzamide does not increase the yields of chromosomal aberrant cells induced by boron neutron capture reaction in V79 Chinese hamster cells

    International Nuclear Information System (INIS)

    Full text: Mechanistic knowledge on DNA and cell damage induced by alpha-particles remains limited. It is well known that high-LET radiation induces both DNA single (ssb) and double strand breaks (dsb), being the latter frequently associated with cell death. The repair of these DNA lesions and specially dsb are thus fundamental for the understanding of high-LET radiation effects. Poly (ADP-ribose) polymerase is a nuclear enzyme, which detects and signals DNA strand breaks (ssb and dsb). The important role of this enzyme in the maintenance of DNA integrity has been extensively studied for genotoxic chemicals and low-LET ionizing radiation. Nevertheless, sparse information concerning the role of PARP in high-LET radiation effects is available. The purpose of this work is to examine whether the PARP inhibitor 3-aminobenzamide (3-AB) enhances the yields of chromosomal aberrations induced by the boron neutron capture (BNC) reaction in V79 Chinese hamster cells. Wild-type V79 cells were pre-incubated for 48 hours with different concentrations (0.48-2.4 mM) of the boron delivery agent 4-borono-L-phenylalanine (BPA) and then irradiated for different periods of time with thermal neutrons. In the 3-AB treated cultures, four hours before the irradiation the cells were incubated with different concentrations of this inhibitor (1.5-10 mM) which remained in culture until colchicine was added. The chromosomal aberrations assay was performed according to standard protocol. A clear dose-response in the frequencies of chromosomal aberrant cells excluding gaps (%CAEG) induced by the BNC reaction was observed for both BPA concentration and thermal neutron fluence. There was no evidence of an increase in the % CAEG induced after incubation with 3-AB. Some cytoxicity was observed (mitotic index) after 3-AB incubation in BPA irradiated cells. In conclusion, the clastogenic potential of the alpha-particles generated through the BNC reaction was not affected by using a classic PARP

  9. Molecular mechanisms in the induction of chromosome aberrations

    International Nuclear Information System (INIS)

    In more recent years there have been attempts to understand the mechanisms giving rise to aberrations on a more molecular basis. This was initially stimulated by the demonstrations of enzyme repair systems in bacteria which repair mutagen-damaged DNA and the obvious suggestion that similar kinds of repair processes in eukaryotes could be responsible for spontaneous and mutagen-induced exchanges in somatic cells, and for recombinational exchanges in meiotic cells. This impetus has been maintained largely by discovery and the acquisition of information on five fronts: (i) increasing knowledge of the and organisation of the eukaryotic chromosome; (ii) a better understanding of the types of lesions induced in DNA by a wide variety of mutagens; (iii) the demonstrations of a variety of repair systems that restore damaged DNA in eukaryotes including man; (iv) the identification and characterisation of mutants defective in DNA repair and which give unusual reponses to aberration induction by specific mutagens; (v) the development of new techniques to visulise sister chromatid exchange and other facets of chromosome substructure. In this presentation some developments are considered and a picture is sketched of our current notions on how recent chromosomal aberrations are formed, by posing a number of questions and attempting to answer them. (Auth.)

  10. Studies on chromosomal aberrations and inherited sterility in Asian corn borer, Ostrinia furnacalis (Guenee)

    International Nuclear Information System (INIS)

    F1 sterility and chromosomal aberrations in the Asian corn borer, Ostrinia furnacalis (Guenee), were induced by different doses of gamma radiation. The chromosome number of the Asian corn borer is n = 31 pairs. The results showed that chromosomal aberrations in spermatocytes of the F1 generation were directly related to high F1 sterility; however, the sterility was observed for only one generation and fertility was recovered in the next generation. (author). 6 refs, 2 figs, 4 tabs

  11. Neoplastic transformation in BALB/3T3 cells induced by 137Cs γ-rays and assessment of chromosome aberrations and unscheduled DNA synthesis

    International Nuclear Information System (INIS)

    The results of this study show that the neoplastic transformation in BALB/3T3 cells can be induced directly by exposure to 137Cs γ-rays. Transformation frequencies for type II and III foci in the 1, 3 and 5 Gy irradiated groups are 14.56, 25.08, and 24.81 x 10-3, respectively, while that in the control group is 1.4 x 10-3. The killing effect of radiation leads to reduction of transformation frequency in the 5 Gy group. Chromosome aberrations in first post-exposure mitosis are 13.5, 22.05 and 41.05 per cent for 1, 3 and 5 Gy groups, respectively, being significantly higher than that in the control (1.5 per cent, P3H-thymidine show that UDS in cells increase significantly with the dose after exposure while no change in sister chromatid exchange is observed

  12. Chromosomal aberrations detected by chromosome painting in lymphocytes from cancer patients given high doses of therapeutic X-rays

    International Nuclear Information System (INIS)

    Chromosome painting by fluorescence in situ hybridization (FISH) with a whole chromosome-specific DNA probe was used to detect chromosomal aberrations in lymphocytes from cancer patients given partial-body fractionated X-ray therapy. Six male patients with cancer of the stomach, prostate, lung, or hepatocellular carcinoma, received X-rays in total doses of 40.5 to 70.08 Gy. Lymphocytes were cultured for 50 h with phytohemagglutinin. The mean frequency of aberrant cells detected by chromosome 4 painting varied from 1.57% to 14.34% in the patients and was markedly higher than in healthy controls (mean=0.12%). Chromosome painting effectively detected chromosomal aberrations in lymphocytes from cancer patients. Equivalent biological doses extrapolated from a dose-response curve obtained in an in vitro human lymphocyte X-ray irradiation study are discussed as an indicator of the cytogenetic damage inducible by radiotherapy in cancer patients. (author)

  13. Stability of chromosome aberrations with post-irradiation time. Implications in retrospective biodosimetry. Chromosome aberration analysis in retrospective biodosimetry

    International Nuclear Information System (INIS)

    The aim of the present study was to evaluate the persistence chromosome aberrations induced by three doses of X-rays. For this purpose fluorescence in situ hybridisation (FISH) painting and multiplex FISH (mFISH) techniques have been applied to a long-term culture of irradiated cells. By painting, at 2 Gy the frequency of apparently simple translocations remained almost invariable during all the culture, whereas at 4 Gy a rapid decline was observed between the first and the second sample, followed by a slight decrease until the end of the culture. Apparently simple dicentrics and complex aberrations disappeared after the first sample at 2 and 4 Gy. When simple aberrations analysed by mFISH are considered, at 2 Gy the frequency of complete plus one-way translocations remained invariable between the first and last sample, but at 4 Gy a 60% decline was observed. True incomplete simple translocations disappeared at 2 and 4 Gy. The analysis by mFISH showed that the frequency of complex aberrations and their complexity increased with dose and tends to disappear in the last sample. Our results indicate that the dose influence on the decrease of the frequency of simple translocations with post-irradiation time cannot be fully explained by the disappearance of true incomplete translocations and complex aberrations. (author)

  14. Effect of organoseleneium compound DHSred on gamma radiation induced chromosome aberrations and micronucleus in blood lymphocytes and V79 CH cells

    International Nuclear Information System (INIS)

    Experiments were carried out using the blood samples from two healthy donors to assess the modifying effects of organoseleneium compound, DL-trans-3,4-dihydroxy-1-selenolane (DHSred), on Cobalt-60 gamma radiation induced chromosomal aberrations in peripheral blood lymphocytes. The compound DHSred is water soluble and has been found to be non-toxic and exhibit antioxidant and radioprotective activity. Radiation dose employed was 4 Gy whereas DHSred pre-treatment was carried out with concentrations ranging from 0.5 to 10 μg/ml. The results indicated that DHSred pre-treatment significantly decreased the frequency of radiation induced dicentric aberrations in a dose dependant manner. The highest reduction of 54% was observed with 0.5 μg/ml of DHSred pretreatment. In another experiment exponentially growing V79 CH (lung, Chinese Hamster) cells were used. The induced damage was measured by Cytokinesis blocked micronucleus assay. V79 CH cells treated without or with DHSred (0.1 - 3 μg/ml) for 1h were exposed to 2Gy of gamma radiation. About 3h after irradiation the drug containing medium was replaced with fresh medium containing 5 μg/ml cytochalasin B to blok Cytokinesis. The cells were allowed to grow for further 16 h and slides were prepared by modified protocol of Fenech and Morely. The results indicated significant reduction (45-60%) in the radiation induced MN frequency and protection of blood lymphocyte. Being non-toxic and water soluble this compound, DHSred can be explored for potential application in radiotherapy and radioprotection. (author)

  15. Antioxidants in aqueous extract of Myristicafragrans (Houtt.) suppress mitosis and cyclophosphamide-induced chromosomal aberrations in Allium cepa L.cells

    Institute of Scientific and Technical Information of China (English)

    Akeem AKINBORO; Kamaruzaman Bin MOHAMED; Mohd Zaini ASMAWI; Shaida Fariza SULAIMAN; Othman Ahmad SOFIMAN

    2011-01-01

    In this study,freeze-dried water extract from the leaves of Myristica fragrans (Houtt.) was tested for mutagenic and antimutagenic potentials using the Allium cepa assay.Freeze-dried water extract alone and its combination with cyclophosphamide (CP) (50 mg/kg) were separately dissolved in tap water at 500,1000,2000,and 4000 mg/kg.Onions (A.cepa) were suspended in the solutions and controls for 48 h in the dark.Root tips were prepared for microscopic evaluation.2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radicals' scavenging power of the extract was tested using butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as standards.Water extract of Myristica fragrans scavenged free radicals better than BHA,but worse than BHT.The extract alone,as well as in combination with CP suppressed cell division,and induced chromosomal aberrations that were insignificantly different from the negative control (P≤0.05).However,cytotoxic and mutagenic actions of CP were considerably suppressed.The observed effects on cell division and chromosomes of A.cepa may be principally connected to the antioxidant properties of the extract.The obtained results suggest mitodepressive and antimutagenic potentials of water extract of the leaves of M.fragrans as desirable properties of a promising anticancer agent.

  16. Pattern of Chromosomal Aberrations in Patients from North East Iran

    Directory of Open Access Journals (Sweden)

    Saeedeh Ghazaey

    2013-01-01

    Full Text Available Objective: Chromosomal aberrations are common causes of multiple anomaly syndromes. Recurrent chromosomal aberrations have been identified by conventional cytogenetic methods used widely as one of the most important clinical diagnostic techniques.Materials and Methods: In this retrospective study, the incidences of chromosomal aberrations were evaluated in a six year period from 2005 to 2011 in Pardis Clinical and Genetics Laboratory on patients referred to from Mashhad and other cities in Khorasan province. Karyotyping was performed on 3728 patients suspected of having chromosomal abnormalities.Results: The frequencies of the different types of chromosomal abnormalities were determined, and the relative frequencies were calculated in each group. Among these patients, 83.3% had normal karyotypes with no aberrations. The overall incidences of chromosomal abnormalities were 16.7% including sex and autosomal chromosomal anomalies. Of those, 75.1 % showed autosomal chromosomal aberrations. Down syndrome (DS was the most prevalent autosomal aberration in the patients (77.1%. Pericentric inversion of chromosome 9 was seen in 5% of patients. This inversion was prevalent in patients with recurrent spontaneous abortion (RSA. Sex chromosomal aberrations were observed in 24.9% of abnormal patients of which 61% had Turner’s syndrome and 33.5% had Klinefelter’s syndrome.Conclusion: According to the current study, the pattern of chromosomal aberrations in North East of Iran demonstrates the importance of cytogenetic evaluation in patients who show clinical abnormalities. These findings provide a reason for preparing a local cytogenetic data bank to enhance genetic counseling of families who require this service.

  17. Heterogeneity of chromosome damage in β-thalassaemia traits. An evaluation of spontaneous and γ-ray-induced micronuclei and chromosome aberrations in lymphocytes in vitro after G0 and G2 phase irradiation

    International Nuclear Information System (INIS)

    This study is an attempt to evaluate the chromosomal radiosensitivity of β-thalassaemia traits compared with healthy individuals from the general population, necessitated by the fact that β-thalassaemia trait is present in 1-17% of different population groups in India and the chances of encountering them in radiation and chemical related industries do exist. Spontaneous chromosome aberration frequencies in peripheral blood lymphocytes from β-thalassaemia traits were found to be in the normal range, whereas significantly higher frequencies of micronuclei (MN) were observed in thalassaemia traits. Based on MN frequency at 2 Gy, β-thalassaemia traits fall into two distinct categories. A hypersensitive group with significant increase in radiation-induced MN over the control group, and a second group with MN frequency slightly above normal individuals. Even when compared with the fitted data at 2 Gy obtained from the pooled results of extensive dose-response investigations from 0.5-5 Gy γ-rays with normal donors for MN, dicentrics and total aberrations, the difference between the means of MN frequencies in β-thalassaemia traits and normals is significant. (author)

  18. Heterogeneity of chromosome damage in [beta]-thalassaemia traits. An evaluation of spontaneous and [gamma]-ray-induced micronuclei and chromosome aberrations in lymphocytes in vitro after G[sub 0] and G[sub 2] phase irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Krishnaja, A.P.; Sharma, N.K. (Bhabha Atomic Research Centre, Bombay (India). Molecular Biology and Agriculture Div.)

    1994-07-01

    This study is an attempt to evaluate the chromosomal radiosensitivity of [beta]-thalassaemia traits compared with healthy individuals from the general population, necessitated by the fact that [beta]-thalassaemia trait is present in 1-17% of different population groups in India and the chances of encountering them in radiation and chemical related industries do exist. Spontaneous chromosome aberration frequencies in peripheral blood lymphocytes from [beta]-thalassaemia traits were found to be in the normal range, whereas significantly higher frequencies of micronuclei (MN) were observed in thalassaemia traits. Based on MN frequency at 2 Gy, [beta]-thalassaemia traits fall into two distinct categories. A hypersensitive group with significant increase in radiation-induced MN over the control group, and a second group with MN frequency slightly above normal individuals. Even when compared with the fitted data at 2 Gy obtained from the pooled results of extensive dose-response investigations from 0.5-5 Gy [gamma]-rays with normal donors for MN, dicentrics and total aberrations, the difference between the means of MN frequencies in [beta]-thalassaemia traits and normals is significant. (author).

  19. Radiation-induced chromosome aberrations occurring during the first and second mitotic divisions of human lymphocytes after exposure to X-rays

    International Nuclear Information System (INIS)

    The study described elucidates the relationship between the number of chromosome aberrations/cell and the length of the individual culture periods. The BrdUrd staining technique used here permitted separate analyses of the aberration frequencies during the first and second mitotic divisions of lymphocyte chromosomes cultivated for different periods of time. The results thus obtained were subjected to further analysis to quantify errors attributable to non-separate observations of such mitotic processes and to determine the number of surviving cells observed to have dicentric chromosomes during the first mitotic division. An analysis of the results obtained for the first mitotic division alone failed to reveal any connection between the number of chromosome aberrations and the culture periods. The aberration rates established for the second mitotic division were clearly related to the culture periods. A steady state was reached after approx. 54 h, but the values determined here were much lower than those calculated for the first mitotic division. (orig./MG)

  20. 雄黄致体内外染色体畸变%Studies on in vivo and in vitro Hamster Chromosome Aberration Induced by Realgar

    Institute of Scientific and Technical Information of China (English)

    赵源; 吴文斌; 汤家铭

    2012-01-01

    目的:用仓鼠体内染色体畸变试验和中国仓鼠肺细胞CHL细胞染色体畸变试验评价雄黄的遗传毒性.方法:体内染色体畸变试验用毛足属仓鼠连续ig5 d给予33.25,66.5,133 mg·kg-1剂量雄黄悬浊液,处死前2 h ip秋水仙素.处死后取骨髓细胞制备染色体.油镜下观察每只动物骨髓细胞的有丝分裂指数和100个中期分裂相细胞的畸变类型.CHL细胞染色体畸变试验用雄黄浸出液终质量浓度为0.15,0.3,0.6g.L-1作用于CHL细胞,培养24 h或48 h,终止培养前4h加入秋水仙素.收获细胞,制备染色体,油镜下观察CHL细胞有丝分裂指数和200个中期分裂相细胞的畸变类型.结果:①雄黄265.0 mg· kg -1组和雄黄530.0 mg·kg-1组ig给药和雄黄浸出液(1.2,2.4g·L-1)作用于CHL细胞显示有明显的抑制有丝分裂作用.②与阴性对照组比较,雄黄ig给药仓鼠体内染色体畸变率和雄黄体外给药CHL细胞染色体畸变率均显著升高,差异有极显著意义,且有明显的量效关系.但体内试验的畸变率低于体外试验.③雄黄给药后CHL细胞染色体畸变试验中可见较多的染色体断片,而仓鼠体内染色体畸变试验中未发现,这可能与体内外药物作用的方式不同.结论:①雄黄能致体内外细胞染色体畸变,具有遗传毒性.②仓鼠体内染色体畸变试验可作为中药新药遗传毒性评价试验组合的方法之一.%Objective; To evaluate the genetic toxicity of realgar by using Hamster in vivo chromosome aberration test and CHL cells chromosome aberration test. Method; For in vivo chromosome aberration test, hamsters ( Phodopus sungorus) were used to realgar suspension at doses of ,33. 25, 66.5, 133 mg·kg-1 respectively for 5 days by ig administration. Colchicine was injected intraperitoneally 2 h before sacrificed. Bone marrow cells were taken to prepare chromosome smears. Mitotic index of bone marrow cells and types of chromosome aberration in 100 metaphase

  1. Chromosome aberration analysis based on a beta-binomial distribution

    International Nuclear Information System (INIS)

    Analyses carried out here generalized on earlier studies of chromosomal aberrations in the populations of Hiroshima and Nagasaki, by allowing extra-binomial variation in aberrant cell counts corresponding to within-subject correlations in cell aberrations. Strong within-subject correlations were detected with corresponding standard errors for the average number of aberrant cells that were often substantially larger than was previously assumed. The extra-binomial variation is accomodated in the analysis in the present report, as described in the section on dose-response models, by using a beta-binomial (B-B) variance structure. It is emphasized that we have generally satisfactory agreement between the observed and the B-B fitted frequencies by city-dose category. The chromosomal aberration data considered here are not extensive enough to allow a precise discrimination between competing dose-response models. A quadratic gamma ray and linear neutron model, however, most closely fits the chromosome data. (author)

  2. Chromosome Aberrations Induced in Human Peripheral Blood by 2-MeV X-Irradiation to the Whole Body and In Vitro

    International Nuclear Information System (INIS)

    In recent years it has proved possible to correlate the incidence of ring and dicentric chromosomes in cultured human peripheral blood lymphocytes with given radiation doses both in vitro and following partial or whole body irradiation exposure in vivo In the present study a comparison is made between the yield of aberrations in six men with advanced cancer who received whole body irradiation in doses varying between 36 and 50 rads and the yield of aberrations in samples of their blood drawn before exposure and irradiated in vitro simultaneously to the same dose A comparison is also made between the yield of aberrations following in vitro irradiation to much higher doses of blood derived from these same cancer patients and blood from non cancer controls The significance of these findings is discussed with reference to biological dosimetry using chromosome aberrations as the parameter for both external and internal irradiation Apart from such a practical application it also appears possible to develop this technique to study the sensitivity of cells to chromosome breakage by radiation in selected populations such as mongols or persons with Fancom s anaemia where there is a higher than normal incidence of malignant disease. (author)

  3. Chromosome aberrations in pesticide-exposed greenhouse workers

    DEFF Research Database (Denmark)

    Lander, B F; Knudsen, Lisbeth E.; Gamborg, M O;

    2000-01-01

    OBJECTIVES: The aim of this study was to investigate the possibility of subtoxic exposure to pesticides causing chromosome aberrations in greenhouse workers. METHODS: In a cross-sectional and prospective study design chromosome aberration frequencies in cultured lymphocytes were examined for 116...... greenhouse workers exposed to a complex mixture of almost 50 insecticides, fungicides, and growth regulators and also for 29 nonsmoking, nonpesticide-exposed referents. RESULTS: The preseason frequencies of chromosome aberrations were slightly but not statistically significantly elevated for the greenhouse...... workers when they were compared with the referents. After a summer season of pesticide spraying in the greenhouses, the total frequencies of cells with chromosome aberrations were significantly higher than in the preseason samples (P=0.02) and also higher than for the referents (P=0.05). This finding was...

  4. Lymphocyte chromosome aberrations in partial-body fractionated radiation therapy

    International Nuclear Information System (INIS)

    a relationship between lymphocyte chromosome aberration yields which occur in partial-body fractionated radiation therapy and those yields measured in vitro is derived. These calculations are applied to the case of patients undergoing radiation therapy for mammary carcinoma. (author)

  5. Lymphocyte chromosome aberrations in partial-body fractionated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ekstrand, K.E.; Dixon, R.L. (Wake Forest Univ., Winston-Salem, NC (USA))

    1982-03-01

    a relationship between lymphocyte chromosome aberration yields which occur in partial-body fractionated radiation therapy and those yields measured in vitro is derived. These calculations are applied to the case of patients undergoing radiation therapy for mammary carcinoma.

  6. Studies of X-ray-induced chromosome aberrations in cells of the black-tailed wallaby. I

    International Nuclear Information System (INIS)

    The distribution of exchanges between individual chromosome arms in mitotic peripheral blood cells following X-irradiation in G0 has been measured. It was found that, although all arms exchanged with each other, there were small but significant departures from the frequcies expected on the basis of random breakage and exchange. It is suggested that non-randomness may reflect the non-uniform state of condensation of chromatin in G0 lymphocytes. (Auth.)

  7. Chromosome aberrations in solid tumors have a stochastic nature

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Mauro A.A. [Departamento de Bioquimica, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600-anexo, Porto Alegre 90035-003 (Brazil) and Departamento de Medicina Interna, Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2350, Porto Alegre 90035-903 (Brazil) and Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, Porto Alegre 91501-970 (Brazil) and Universidade Luterana do Brasil, Rua Miguel Tostes 101, Canoas 92420-280 (Brazil)]. E-mail: mauro@ufrgs.br; Onsten, Tor G.H. [Departamento de Medicina Interna, Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2350, Porto Alegre 90035-903 (Brazil); Universidade Luterana do Brasil, Rua Miguel Tostes 101, Canoas 92420-280 (Brazil); Moreira, Jose C.F. [Departamento de Bioquimica, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600-anexo, Porto Alegre 90035-003 (Brazil); Almeida, Rita M.C. de [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, Porto Alegre 91501-970 (Brazil)

    2006-08-30

    An important question nowadays is whether chromosome aberrations are random events or arise from an internal deterministic mechanism, which leads to the delicate task of quantifying the degree of randomness. For this purpose, we have defined several Shannon information functions to evaluate disorder inside a tumor and between tumors of the same kind. We have considered 79 different kinds of solid tumors with 30 or more karyotypes retrieved from the Mitelman Database of Chromosome Aberrations in Cancer. The Kaplan-Meier cumulative survival was also obtained for each solid tumor type in order to correlate data with tumor malignance. The results here show that aberration spread is specific for each tumor type, with high degree of diversity for those tumor types with worst survival indices. Those tumor types with preferential variants (e.g. high proportion of a given karyotype) have shown better survival statistics, indicating that aberration recurrence is a good prognosis. Indeed, global spread of both numerical and structural abnormalities demonstrates the stochastic nature of chromosome aberrations by setting a signature of randomness associated to the production of disorder. These results also indicate that tumor malignancy correlates not only with karyotypic diversity taken from different tumor types but also taken from single tumors. Therefore, by quantifying aberration spread, we could confront diverse models and verify which of them points to the most likely outcome. Our results suggest that the generating process of chromosome aberrations is neither deterministic nor totally random, but produces variations that are distributed between these two boundaries.

  8. Failure of antimony trioxide to induce micronuclei or chromosomal aberrations in rat bone-marrow after sub-chronic oral dosing.

    Science.gov (United States)

    Kirkland, David; Whitwell, James; Deyo, James; Serex, Tessa

    2007-03-01

    Antimony trioxide (Sb2O3, CAS 1309-64-4) is widely used as a flame retardant synergist in a number of household products, as a fining agent in glass manufacture, and as a catalyst in the manufacture of various types of polyester plastics. It does not induce point mutations in bacteria or mammalian cells, but is able to induce chromosomal aberrations (CA) in cultured cells in vitro. Although no CA or micronuclei (MN) have been induced after acute oral dosing of mice, repeated oral dosing for 14 or 21 days resulted in increased CA in one report, but did not result in increased MN in another. In order to further investigate its in vivo genotoxicity, Sb2O3 was dosed orally to groups of rats for 21 days at 250, 500 and 1000 mg/kg day. There were no clinical signs of toxicity in the Sb2O3-exposed animals except for some reductions in body-weight gain in the top dose group. Toxicokinetic measurements in a separate study confirmed bone-marrow exposure, and at higher levels than would have been achieved by single oral dosing. Large numbers of cells were scored for CA (600 metaphases/sex group) and MN (12,000 PCE/sex group) but frequencies of CA or MN in Sb2O3-treated rats were very similar to controls, and not biologically or statistically different, at all doses. These results provide further indication that Sb2O3 is not genotoxic to the bone marrow of rodents after 21 days of oral administration at high doses close to the maximum tolerated dose. PMID:17174592

  9. The nonlinear relationship of radiation dose to chromosome aberrations among atomic bomb survivors, Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    The quantitative relationship of the frequency of cells with radiation-induced chromosome aberrations in peripheral leukocytes in atomic bomb survivors has been evaluated as a function of gamma and neutron doses. Three different models have been examined; each assumes a nonlinear-response to gamma rays and a linear-response to neutrons. From the standpoint of the goodness of fit of these models, the model which ''best'' fits the data of radiation-induced chromosome aberrations is the exponit model, where the frequency of aberrant cells increases exponentially with dose. It is of radiobiological interest that the goodness of fit for this model shows the frequencies of cells with any chromosome aberration or an exchange aberration to be dependent cubically on the gamma ray dose and linearly on the neutron dose. The relative biological effectiveness (RBE) of neutrons is calculated to be 129Dn sup(-2/3) (95% confidence intervals: (121 -- 137)Dn sup(-2/3)) for frequency of cells with any chromosome aberration, and 125Dn sup(-2/3) (95% confidence intervals: (117 -- 132)Dn sup(-2/3)) for the frequency of cells with an exchange aberration where Dn is the neutron dose. (author)

  10. Biological dosimetry: chromosomal aberration analysis for dose assessment

    International Nuclear Information System (INIS)

    In view of the growing importance of chromosomal aberration analysis as a biological dosimeter, the present report provides a concise summary of the scientific background of the subject and a comprehensive source of information at the technical level. After a review of the basic principles of radiation dosimetry and radiation biology basic information on the biology of lymphocytes, the structure of chromosomes and the classification of chromosomal aberrations are presented. This is followed by a presentation of techniques for collecting blood, storing, transporting, culturing, making chromosomal preparations and scaring of aberrations. The physical and statistical parameters involved in dose assessment are discussed and examples of actual dose assessments taken from the scientific literature are given

  11. Mechanisms of induction of chromosomal aberrations and their detection by fluorescence in situ hybridization

    International Nuclear Information System (INIS)

    Recently introduced fluorescence in situ hybridization (FISH) technique employing chromosome specific DNA libraries as well as region specific DNA probes (e.g., centromere, telomere) have helped to analyse chromosomal aberrations in great detail and thus have given some new insights into the mechanisms of induction of chromosomal aberrations. The relative proportion of induction of translocations and dicentrics by ionising radiation was studied in human, mice and Chinese hamster cells. Many of the studies point to the differences between the mechanisms of induction of dicentrics and translocations. Preliminary results obtained in our laboratory using arm specific probes for human chromosomes 1 and 3 indicate that the aberrations between the arms appear to be more than expected on a random basis. By employing telomeric probes the frequencies of interstitial deletions were found to be high and similar to the frequencies of dicentrics both in human and mouse lymphocytes. A recent study with human chromosome specific probes clearly shows variation of sensitivity of chromosomes for the induction of exchange aberrations. Radiation response studies with Chinese hamster cells using telomeric probes, suggest that telomeric sequences, especially interstitial ones appear to be an important factor in the origin of both spontaneous and induced chromosomal aberrations

  12. Stable chromosome aberrations in the reconstruction of radiation doses

    International Nuclear Information System (INIS)

    Chromosome-type aberrations, such as dicentric and translocation chromosomes, are biomarkers of exposure to ionizing radiation. So far, analysis of dicentric chromosomes in peripheral blood lymphocytes has been the only method routinely used in biological dose assessment. During division of T cell precursors, proliferative death of cells containing dicentric chromosomes reduces the number of such lymphocytes in peripheral blood. Dicentrics are thus suitable for dose calculations during a reasonably short period after exposure to radiation. Unlike dicentrics, translocations persist in cell division and enable dose estimation over long time periods following exposure. A recent development in molecular biology, the FISH (fluorescence in situ hybridization) chromosome-painting technique, has opened the possibility for accurate recognition of translocations and thus retrospective determination of dose. The purpose of the present study was to evaluate the applicability of translocation analysis by means of FISH chromosome painting for retrospective dosimetry. In the construction of acute dose-effect curves for 60Co g-ray-induced chromosomal aberrations using FISH chromosome painting, translocations showed a linear-quadratic relationship to dose, similar to that seen in dicentrics. Donor-dependent translocation frequencies at control level and at low doses were observed. The linear part of the calibration curve for two way translocations, i.e. both translocation chromosomes present, proved to be more reliable than the comparable low-dose response for total translocations, which include both two- and one-way translocations. The results indicate that the linear part of the curve requires precise determination, particularly since application of the technique will probably cover mainly chronically exposed subjects. An opportunity to gain direct information on translocation persistence over time was opened by obtaining repeated samples from subjects accidentally exposed to

  13. Comparative analysis of chromosome aberrations induced in human lymphocytes in vitro by various types of ionizing radiations

    International Nuclear Information System (INIS)

    Certain problems of comparative analyses of radiation-induced dicentrics in human lymphocytes following various types of ionizing radiations are considered as follows: 1. Equations best fitting for dose-response kinetics; 2. Use of dicentrics for analysing the RBE of various types of radiations; 3. The relationship between RBE and LET as seen by the analysis of dicentrics. (author)

  14. Mathematical Modeling of Carcinogenesis Based on Chromosome Aberration Data

    Institute of Scientific and Technical Information of China (English)

    Xiao-bo Li

    2009-01-01

    Objective: The progression of human cancer is characterized by the accumulation of genetic instability. An increasing number of experimental genetic molecular techniques have been used to detect chromosome aberrations. Previous studies on chromosome abnormalities often focused on identifying the frequent loci of chromosome alterations, but rarely addressed the issue of interrelationship of chromosomal abnormalities. In the last few years, several mathematical models have been employed to construct models of carcinogenesis, in an attempt to identify the time order and cause-and-effect relationship of chromosome aberrations. The principles and applications of these models are reviewed and compared in this paper. Mathematical modeling of carcinogenesis can contribute to our understanding of the molecular genetics of tumor development, and identification of cancer related genes, thus leading to improved clinical practice of cancer.

  15. Frequency of Early and Late Chromosome Aberrations in Different Types of Cells After Proton and Fe Ion Irradiation

    Science.gov (United States)

    Lu, Tao; Zhang, Ye; Yeshitla, Samrawit; Bowler, Deborah; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2016-01-01

    DNA damages induced by space radiation, consisting of protons and high-LET charged particles, can be complex in nature, which are often left unrepaired and cause chromosomal aberrations. Increased level of genomic instability is attributed to tumorigenesis and increased cancer risks. To investigate genomic instability induced by charged particles, human lymphocytes ex vivo, human fibroblasts, and human mammary epithelial cells, as well as mouse bone marrow stem cells isolated from CBA/CaH and C57BL/6 strains were exposed to high energy protons and Fe ions. Metaphase chromosome spreads at different cell divisions after radiation exposure were collected and, chromosome aberrations were analyzed with fluorescence in situ hybridization with whole chromosome-specific probes for human cells. With proton irradiation, levels of chromosome aberrations decreased by about 50% in both lymphocytes and epithelial cells after multiple cell divisions, compared to initial chromosome aberrations at 48 hours post irradiation in both cell types. With Fe ion irradiation, however, the frequency of chromosome aberrations in lymphocytes after multiple cell divisions was significantly lower than that in epithelial cells at comparable cell divisions, while their initial chromosome aberrations were at similar levels. Similar to the human cells, after Fe ion irradiation, the frequency of late chromosome aberrations was similar to that of the early damages for radio-sensitive CBA cells, but different for radio-resistant C57 cells. Our results suggest that relative biological effectiveness (RBE) values are dependent not only on radiation sources, but also on cell types and cell divisions.

  16. Estimation of dose from chromosome aberration rate

    International Nuclear Information System (INIS)

    The methods and skills of evaluating dose from correctly scored shromsome aberration rate are presented, and supplemented with corresponding BASIC computer code. The possibility and preventive measures of excessive probability of missing score of the aberrations in some of the current routine score methods are discussed. The use of dose-effect relationship with exposure time correction factor G in evaluating doses and their confidence intervals, dose estimation in mixed n-γ exposure, and identification of high by nonuniform acute exposure to low LET radiation and its dose estimation are discussed in more detail. The difference of estimated dose due to whether the interaction between subleisoms produced by n and γ have been taken into account is examined. In fitting the standard dose-aberration rate curve, proper weighing of experiment points and comparison with commonly accepted values are emphasised, and the coefficient of variation σy√y of the aberration rate y as a function of dose and exposure time is given. In appendix I and II, the dose-aberration rate formula is derived from dual action theory, and the time variation of subleisom is illustrated and in appendix III, the estimation of dose from scores of two different types of aberrations (of other related score) is illustrated. Two computer codes are given in appendix IV, one is a simple code, the other a complete code, including the fitting of standard curve. the skills of using compressed data storage, and the production of simulated 'data ' for testing the curve fitting procedure are also given

  17. Radiation-induced chromosomal instability

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, S. [GSI, Biophysics, Darmstadt (Germany)

    1999-03-01

    Recent studies on radiation-induced chromosomal instability in the progeny of exposed mammalian cells were briefly described as well as other related studies. For the analysis of chromosomal damage in clones, cells were seeded directly after exposure in cell well-dish to form single cell clones and post-irradiation chromosome aberrations were scored. Both exposure to isoeffective doses of X-ray or 270 MeV/u C-ions (13 keV/{mu}m) increased the number of clones with abnormal karyotype and the increase was similar for X-ray and for C-ions. Meanwhile, in the progeny of cells for mass cultures, there was no indication of a delayed expression of chromosomal damage up to 40 population doublings after the exposure. A high number of aberrant cells were only observed directly after exposure to 10.7 MeV/u O-ions, i.e. in the first cycle cells and decreased with subsequent cell divisions. The reason for these differences in the radiation-induced chromosomal instability between clonal isolates and mass culture has not been clarified. Recent studies indicated that genomic instability occurs at a high frequency in the progeny of cells irradiated with both sparsely and densely ionizing radiation. Such genomic instability is thought likely to increase the risk of carcinogenesis, but more data are required for a well understanding of the health risks resulting from radiation-induced delayed instability. (M.N.)

  18. Biological radiation dose estimation by chromosomal aberrations analysis in human peripheral blood (dose-effect curve)

    International Nuclear Information System (INIS)

    In order to draw a dose-effect curve, experimentally gamma ray induced chromosomal aberrations in human peripheral lymphocytes from eight healthy people were studied. Samples from 4 males and 4 females were irradiated in tubes with 0.15, 0.25, 0.5, 1, 1.5, 2, 2.5 gray of gamma ray (Co60 at dose rate 0.3 Gy/min). Irradiated and control samples were incubated in 37 centigrade for 48 hours cell cultures. Cell cultures then were stopped and metaphases spread, Giemsa stained to score the induced chromosomal aberrations. Chromosomal aberrations from 67888 metaphases were scored. Curves from the total number of dicentrics, dicentrics + rings and total numbers of breaks in cell for each individual or for all people were drawn. An increase of all chromosomal aberrations types with the elevation of the doses was observed. The yield of chromosome aberrations is related to the dose used. These curves give a quick useful estimation of the accidentally radiation exposure. (author)

  19. Chromosome aberrations in workers of beach sand mineral industries

    International Nuclear Information System (INIS)

    Beach Sand Mining (BSM) is a profitable industry earning a sizable income for the country by way of foreign exchange. The Indian coast is rich in rare earths such as ilmenite, rutile, leucoxene, zircon, garnet and sillimanite, and is invariably associated with radioactive monazite. Due to the nature of the separation processes involved and the manual handling, workers in these factories are continuously being exposed to suspended particles containing naturally occurring radioactive materials. An attempt was made to estimate DNA damage using a chromosome aberration assay to monitor radiation effects in workers of BSM industries in India. The study group comprised 27 BSM workers and 20 controls. Percentage yields of dicentrics, acentric fragments and chromatid breaks observed in the control group were 0.058 ± 0.017, 0.073 ± 0.03 and 0.22 ± 0.112, respectively. Percentage yields of dicentrics + centric rings, acentric fragments and chromatid breaks observed in the BSM group were 0.029 ± 0.01 (P value 0.19), 0.24 ± 0.06 (P value 0.006) and 0.455 ± 0.06 (P value 0.0004), respectively. Elevated levels of fragments and chromatid aberrations are suggestive of low-dose radiation effects and also chemically-induced DNA damage. (authors)

  20. Chromosome aberrations in relation to radiation dose following partial-body exposures in three populations

    International Nuclear Information System (INIS)

    Structural chromosome aberrations were evaluated in peripheral blood samples obtained from three populations exposed to partial-body irradiation. These included 143 persons who received radiotherapy for enlarged thymus glands during infancy and 50 sibling controls; 79 persons irradiated for enlarged tonsils and 81 persons surgically treated for the same condition during childhood; and 77 women frequently exposed as young adults to fluoroscopic chest X rays during lung collapse treatment for tuberculosis (TB) and 66 women of similar ages treated for TB with other therapies. Radiation exposures occurred 30 and more years before blood was drawn. Doses to active bone marrow averaged over the entire body were 21, 6, and 14 cGy for the exposed thymic, tonsil, and TB subjects, respectively. Two hundred metaphases were scored for each subject, and the frequencies of symmetrical (stable) and asymmetrical (unstable) chromosome aberrations were quantified in 97,200 metaphases. Cells with stable aberrations were detected with greater frequency in the irradiated subjects compared with nonirradiated subjects in all three populations, and an overall test for an association between stable aberrations and partial-body ionizing radiation was highly significant (P less than 0.001). We found no evidence that radiation-induced aberrations varied by age at exposure. These data show that exposure of children or young adults to partial-body fractionated radiation can result in detectable increased frequencies of stable chromosome aberrations in circulating lymphocytes 30 years later, and that these aberrations appear to be informative as biological markers of population exposure

  1. Effect of pretreatment with venom of Apis mellifera bees on the yield of gamma-ray induced chromosome aberrations in human blood lymphocytes

    International Nuclear Information System (INIS)

    Venom of the honey bee Apis mellifera induced a protective effect against the induction of dicentric chromosomes by gamma radiation (2.0 Gy) in human peripheral blood lymphocytes when the cultures were treated with 0.00015 μl venom/1 ml medium 6 h before irradiation. In cultures to which the venom was added immediately before irradiation with 0.25, 1.0 and 2.0 Gy, no significant differences in number of dicentric chromosomes induced was observed when compared to cultures submitted to irradiation only. The venom did not induce clastogenic effects nor did it increase the frequency of sister chromatid exchanges. (author)

  2. Chromosomal aberrations and SCEs as biomarkers of cancer risk

    Czech Academy of Sciences Publication Activity Database

    Norppa, H.; Bonassi, S.; Hansteen, I. L.; Hagmar, L.; Strömberg, U.; Rössner st., Pavel; Boffetta, P.; Lindholm, C.; Gundy, S.; Lazutka, J.; Cebulska-Wasilewska, A.; Fabiánová, E.; Šrám, Radim; Knudsen, L. E.; Barale, R.; Fucic, A.

    2006-01-01

    Roč. 600, - (2006), s. 37-45. ISSN 0027-5107 Institutional research plan: CEZ:AV0Z50390512 Keywords : biomarkers * chromosomal aberration * sister chromatid exchange Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 4.111, year: 2006

  3. Chromosomal aberration frequency in lymphocytes predicts the risk of cancer

    DEFF Research Database (Denmark)

    Bonassi, Stefano; Norppa, Hannu; Ceppi, Marcello;

    2008-01-01

    Mechanistic evidence linking chromosomal aberration (CA) to early stages of cancer has been recently supported by the results of epidemiological studies that associated CA frequency in peripheral lymphocytes of healthy individuals to future cancer incidence. To overcome the limitations of single...

  4. Telomere Length in Circulating Lymphocytes: Association with Chromosomal Aberrations

    Czech Academy of Sciences Publication Activity Database

    Hemminki, K.; Rachakonda, S.; Musak, L.; Vymetálková, Veronika; Halasová, E.; Forsti,, A.; Vodičková, Ludmila; Buchancová, J.; Vodička, Pavel; Kumar, R.

    2015-01-01

    Roč. 54, č. 3 (2015), s. 194-196. ISSN 1045-2257 Institutional support: RVO:68378041 Keywords : structural chromosome aberrations * healthy subjects * relative telomere length * genotoxicity * telomere biology Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.041, year: 2014

  5. Chromosomal aberrations in tire plant workers and interaction with

    Czech Academy of Sciences Publication Activity Database

    Musak, L.; Souček, P.; Vodičková, Ludmila; Naccarati, Alessio; Halasová, E.; Poláková, Veronika; Slyšková, Jana; Susová, S.; Buchancová, J.; Šmerhovský, Z.; Sediková, J.; Klimentová, G.; Osina, O.; Hemminki, K.; Vodička, Pavel

    2008-01-01

    Roč. 641, 1-2 (2008), s. 36-42. ISSN 0027-5107 R&D Projects: GA MZd NR8563 Institutional research plan: CEZ:AV0Z50390512 Keywords : Chromosomal aberrations * Genetic polymorphisms * DNA repair genes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.198, year: 2008

  6. Frequency of primary amenorrhea due to chromosomal aberration

    International Nuclear Information System (INIS)

    Objective: To find out the frequency of primary amenorrhea due to chromosomal aberration and the different options available for management. Subjects and Methods: All patients with primary amenorrhea due to chromosomal aberrations were included in study. Patient's detailed history, general physical examination, presence or absence of secondary sexual characteristics, abdominal and pelvic examination finding were noted. Targeted investigations, including ultrasound, hormonal assay, buccal smear and karyotyping results were recorded. The management options were individually tailored with focus n psychological management. Results: Eighteen patients out of 30,000 patients were diagnosed as having primary amenorrhea. Six had primary amenorrhea due to chromosomal aberrations with the frequency of 0.02%. The age at presentation was 20 years and above in 50%. The most common cause was Turner's syndrome seen in 4 out of 6. The presenting symptoms were delay in onset of menstruation in 05 patients and primary infertility in 01 patient. Conclusion: Primary amenorrhea due to chromosomal aberration is an uncommon condition requiring an early and accurate diagnosis. Turner's syndrome is a relatively common cause of this condition. Management should be multi-disciplinary and individualized according to the patient's age and symptom at presentation. Psychological management is very important and counselling throughout treatment is recommended. (author)

  7. Oxidative stress and chromosomal aberrations in an environmentally exposed population

    Czech Academy of Sciences Publication Activity Database

    Rössner ml., Pavel; Rössnerová, Andrea; Šrám, Radim

    2011-01-01

    Roč. 707, 1-2 (2011), s. 34-41. ISSN 0027-5107 R&D Projects: GA MŽP(CZ) SP/1B3/8/08 Institutional research plan: CEZ:AV0Z50390512 Keywords : air pollution * oxidative stress * chromosomal aberrations Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.850, year: 2011

  8. Frequency of chromosomal aberrations in Prague mothers and their newborns.

    Czech Academy of Sciences Publication Activity Database

    Rössnerová, Andrea; Balascak, I.; Rössner ml., Pavel; Šrám, Radim

    2010-01-01

    Roč. 699, 1-2 (2010), s. 29-34. ISSN 1383-5718 R&D Projects: GA MŠk 2B06088 Institutional research plan: CEZ:AV0Z50390512 Keywords : Carcinogenic polycyclic aromatic hydrocarbons * Chromosomal aberrations * Fluorescence in situ hybridization Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.938, year: 2010

  9. Numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and Arabidopsis thaliana

    NARCIS (Netherlands)

    Ji, X.

    2014-01-01

    Numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and Arabidopsis thaliana. I studied numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and Arabidopsis thaliana. The large genomic changes are important for

  10. Chromosome Aberrations in Human Lymphocytes Irradiated with Ionizing Radiation

    International Nuclear Information System (INIS)

    The purpose of the present experiment was to provide data on the dose-dependent production of chromosome aberrations such as dicentrics, centric rings, and excess acentrics. Radiation is one of the more dangerous clastogens in the environment. Ionizing radiation causes chromosome breakages and various cytogenetic aberrations in exposed cells. In an investigation into radiation emergencies, it is important to estimate the dose to exposed persons for several reasons. Physical dosimeters (e. g., film badges) may misrepresent the actual radiation dose and may not be available in a radiological accident or terrorism incident. Biological dosimetry is suitable for estimating the radiation dose during such accidents. The dicentric chromosome assay is very sensitive and a reliable bio-indicator in cases of accidental overexposure

  11. Influence of preliminary chronic irradiation and treatment with. cap alpha. -tocopherol on the frequency of chromosome aberrations in mouse bone marrow cells induced by acute. gamma. -irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, A.A.; Akhundov, V.Yu.; Alekperov, U.K.; Gamzaeva, I.A.; Asadova, A.I.; Shekhtman, A.B.; Gabaj, N.S. (AN Azerbajdzhanskoj SSR, Baku. Inst. Botaniki)

    The incidence of chromosome aberrations in bone marrow cells of femur did not exceed the spontaneous one in CBA mice exposed, during 70 days, to ..gamma..-radiation at dose-rates of 33.7-35.8 nA/kg and cumulative dose of 2.75 Gy. A single acute exposure of intact animals to a dose of 2.98 Gy increased significantly the mutation level. Preirradiation with small doses increased the resistance of hereditary structures to sublethal radiation doses. Exogenous ..cap alpha..-tocopherol (0.06 mg/20 g mass) protected the genetic apparatus of cells from total-body irradiation and was an additional factor decreasing the mutaton level after acute exposure of mice at the background of long-term irradiation with small doses.

  12. RBE of Energetic Iron Ions for the Induction of Early and Late Chromosome Aberrations in Different Cell Types

    Science.gov (United States)

    Zhang, Ye; Yeshitla, Samrawit; Hada, Megumi; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2015-01-01

    Numerous published studies have reported the Relative Biological Effectiveness (RBE) values for chromosome aberrations induced by charged particles of different LET. The RBE for chromosome aberrations in human lymphocytes exposed ex vivo has been suggested to show a similar relationship as the quality factor for cancer induction. Therefore, increased chromosome aberrations in the astronauts' white blood cells post long-duration missions are used to determine the biological doses from exposures to space radiation. However, the RBE value is known to be very different for different types of cancer. Previously, we reported that, even though the RBE for initial chromosome damages was high in human lymphocytes exposed to Fe ions, the RBE was significantly reduced after multiple cell divisions post irradiation. To test the hypothesis that RBE values for chromosome aberrations are cell type dependent, and different between early and late damages, we exposed human lymphocytes ex vivo, and human mammary epithelial cells in vitro to various charged particles. Chromosome aberrations were quantified using the samples collected at first mitosis post irradiation for initial damages, and the samples collected after multiple generations for the remaining or late arising aberrations. Results of the study suggested that the effectiveness of high-LET charged particles for late chromosome aberrations may be cell type dependent, even though the RBE values are similar for early damages.

  13. Radiation-induced chromosome aberrations in lymphocytes from man and crab-eating monkey. The dose-response relationships at low doses

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, E.; Hirai, M.; Tobari, I.; Utsugi, T.; Nakai, S. (National Inst. of Radiological Sciences, Chiba (Japan). Div. of Genetics)

    1982-01-01

    To obtain information on the relation between yield of chromosome aberrations and dose at low-dose levels, experiments were conducted with 5, 10, 20, 30 and 50 rad of /sup 137/Cs ..gamma..-rays, on lymphocytes from man and crab-eating monkey (Macaca fascicularis). The dose-response relationship for dicentrics was obtained from the combined data of these low-dose experiments with those of our previous ones at high doses (100-400 rad). When the difference between observed yields and those expected from the linear-quadratic model were computed, the dose-response curve had a good fit for man, but not for the monkey. The linear regression lines between 0 and 30 rad were calculated, because the expected values of ..cap alpha../..beta.. for man and monkey would be about 100 and 60 rad. The human data gave a satisfactory fit to a linear model, i.e., a linear increase in aberration frequency with dose, whereas this was not so for those of the monkey. Furthermore, there was some suggestive evidence for the existence of a plateau in dicentric yields between 10 and 30 rad for the monkey and between 20 and 30 rad for human lymphocytes, but more data would be needed to verify this suggestion, particularly for human lymphocytes.

  14. Analysis of chromosome aberration data by hybrid-scale models

    International Nuclear Information System (INIS)

    This paper presents a new methodology for analyzing data of chromosome aberrations, which is useful to understand the characteristics of dose-response relationships and to construct the calibration curves for the biological dosimetry. The hybrid scale of linear and logarithmic scales brings a particular plotting paper, where the normal section paper, two types of semi-log papers and the log-log paper are continuously connected. The hybrid-hybrid plotting paper may contain nine kinds of linear relationships, and these are conveniently called hybrid scale models. One can systematically select the best-fit model among the nine models by among the conditions for a straight line of data points. A biological interpretation is possible with some hybrid-scale models. In this report, the hybrid scale models were applied to separately reported data on chromosome aberrations in human lymphocytes as well as on chromosome breaks in Tradescantia. The results proved that the proposed models fit the data better than the linear-quadratic model, despite the demerit of the increased number of model parameters. We showed that the hybrid-hybrid model (both variables of dose and response using the hybrid scale) provides the best-fit straight lines to be used as the reliable and readable calibration curves of chromosome aberrations. (author)

  15. Effect of therapeutic hypothermia on chromosomal aberration in perinatal asphyxia

    Directory of Open Access Journals (Sweden)

    Bahubali D Gane

    2016-01-01

    Full Text Available Introduction: Perinatal asphyxia is a major cause for neonatal mortality and morbidity around the world. The reduction of O2results in the generation of reactive oxygen species which interact with nucleic acid and make alteration in the structure and functioning of the genome. We studied the effect of therapeutic hypothermia on chromosomes with karyotyping. Subjects and Methods: Babies in the hypothermia group were cooled for the first 72 h, using gel packs. Rectal temperature of 33–34°C was maintained. Blood sample was collected after completion of therapeutic hypothermia for Chromosomal analysis. It was done with IKAROS Karyotyping system, Metasystems, based on recommendations of International system of human cytogenetic nomenclature. Results: The median chromosomal aberration was lower in hypothermia [2(0-5] than control group [4(1-7] and chromatid breakage was commonest aberration seen. Chromosomal aberration was significantly higher in severe encephalopathy group than moderate encephalopathy group. Conclusion: We conclude that the TH significantly reduces DNA damage in perinatal asphyxia.

  16. Use of the frequencies of micronuclei as quantitative indicators of X-ray-induced chromosomal aberrations in human peripheral blood lymphocytes: comparison of two methods

    International Nuclear Information System (INIS)

    The yield of radiation-induced micronuclei in human lymphocytes was assessed by two methods, i.e., by incorporating bromodeoxyuridine or by inhibiting cytokinesis by cytochalasin for identification of cells which have undergone one cell division. The cytochalasin block method was found to be more efficient with a capacity to detect between 60 and 90% of the induced fragments. Dose-response characteristics and the results of fractionation experiments indicate that the yield of micronuclei reflects both classes of acentric fragments, i.e., those associated and independent of exchange type of aberrations. 8 refs.; 2 figs.; 5 tabs

  17. Types of structural chromosome aberrations and their incidences in human spermatozoa X-irradiated in vitro

    International Nuclear Information System (INIS)

    The authors studied the effects of in vitro X-irradiation on human sperm chromosomes, using our interspecific in vitro fertilization system between human spermatozoa and zona-free hamster oocytes. 28 semen samples from 5 healthy men were exposed to 0.23, 0.45, 0.91 and 1.82 Gy of X-rays. Totals of 2098 and 2862 spermatozoa were karyotyped in the control and the irradiated groups, respectively. The indicence of spermatozoa with X-ray-induced structural chromosome aberrations (Y) increased linearly with increasing dosage (D), being best expressed by the equation, Y = 0.08 + 34.52 D. The incidence of breakage-type aberrations was moe than 9 times higher than that of exchange-type aberrations. Both of them showed linear dose-dependent increases, which were expressed by the regression lines, Y = -0.014 + 0.478 D and Y -0.010 + 0.057 D, respectively. The incidence of chromosome-ltype aberrations was about 6 times higher than that of chromatid-type aberrations. Their dose-dependent increases were expressed by the regression lines, Y = -0.015 + 0.462 D and Y = -0.006 + 0.079 D, respectively. These results are discussed in relation to the previous data obtained with γ-rays. The repair mechanism of X-ray-induced sperm DNA lesions is also discussed. (author). 21 refs.; 4 figs.; 4 tabs

  18. The level of the exchange chromosome aberrations in conditions of the long-term exposure to low doses of radiation

    International Nuclear Information System (INIS)

    Assessment of the chromosomal aberrations level induced by chronic radiation exposure was performed in the personnel of Siberia Chemical Center (radiochemical and fuel cycle centre) and in the population of t. Severs (Tomsk Region) being in the external zone of the above center. It is shown that environmental radioactivity of the Seversk town does not exceed the available standards. Chromosomal aberrations in residents correspond to the standard level, while in personnel of the center 3-5 times higher

  19. Influence of heavy ions on frequency of chromosome aberration in radicle cells for four kinds of plants

    International Nuclear Information System (INIS)

    The experiment results about the influence of C6+ ions with 46.6 MeV/u on types and frequencies of chromosome aberration in radicle cells for four kinds of plants Triticum aestivum L, Cucumis melo var indorous, Lathrus sativus L and lycium barbarum L are presented. Irradiation of heavy ions could seriously inhibit germination ability of seeds and also induce a great number of chromosome aberration in root tip cells

  20. Evaluation of chromosome painting to assess the induction and persistence of chromosome aberrations in bone marrow cells of mice treated with benzene

    Energy Technology Data Exchange (ETDEWEB)

    Stronati, Laura; Farris, Alessandra; Pacchierotti, Francesca

    2004-01-12

    Fluorescence in situ hybridization with chromosome-specific painting probes (FISH painting) has been successfully applied to detect radiation-induced stable aberrations in humans and mice, whereas a few mouse studies with chemicals mostly failed to show any increase in chromosome-painting-detectable changes, especially in bone marrow cells. To further explore the feasibility of the painting approach to detect chemically induced stable aberrations, we treated mice with a single high dose of benzene, a potent bone-marrow-targeting clastogenic chemical and sacrificed them 24, 36 h or 15 days later to collect bone marrow cells and analyze chromatid- and chromosome-type aberrations by FISH painting. In addition, we treated another group of mice with 18 daily low doses to show the potential for aberration induction and accumulation under chronic exposure. Chromatid-type aberrations were significantly increased 24 and 36 h after acute treatment while chromosome-type ones were elevated above control values 36 h and 15 days after exposure, showing that at least part of benzene-induced chromatid exchanges were converted into potentially stable chromosome aberrations. The most common aberration was an extra copy of one painted chromosome in a metaphase with the euploid number of centromeres which was interpreted as the consequence of a symmetric recombination between pericentromeric regions of one painted and one unpainted chromatid. Under chronic exposure, neither chromosome- nor chromatid-type aberrations were significantly elevated over control values, suggesting that the probability of enough primary lesions and secondary DNA double strand breaks occurring close enough together in time to allow chromosome exchanges to form is a critical limiting factor especially in a cycling cell population.

  1. WE-D-BRE-05: Prediction of Late Radiation-Induced Proctitis in Prostate Cancer Patients Using Chromosome Aberration and Cell Proliferation Rate

    Energy Technology Data Exchange (ETDEWEB)

    Oh, J; Deasy, J [Memorial Sloan Kettering Cancer Center, New York, NY (United States)

    2014-06-15

    Purpose: Chromosome damage and cell proliferation rate have been investigated as potential biomarkers for the early prediction of late radiationinduced toxicity. Incorporating these endpoints, we explored the predictive power for late radiation proctitis using a machine learning method. Methods: Recently, Beaton et al. showed that chromosome aberration and cell proliferation rate could be used as biomarkers to predict late radiation proctitis (Beaton et al. (2013) Int J Rad Onc Biol Phys, 85:1346–1352). For the identification of radiosensitive biomarkers, blood samples were collected from 10 patients with grade 3 late proctitis along with 20 control patients with grade 0 proctitis. After irradiation at 6 Gy, statistically significant difference was observed between the two groups, using the number of dicentrics and excess fragments, and the number of cells in metaphase 2 (M2). However, Beaton et al. did not show the usefulness of combining these endpoints. We reanalyzed the dataset to investigate whether incorporating these endpoints can increase the predictive power of radiation proctitis, using a support vector machine (SVM). Results: Using the SVM method with the number of fragments and M2 endpoints, perfect classification was achieved. In addition, to avoid biased estimate of the classification method, leave-one-out cross-validation (LOO-CV) was performed. The best performance was achieved when all three endpoints were used with 87% accuracy, 90% sensitivity, 85% specificity, and 0.85 AUC (the area under the receiver operating characteristic (ROC) curve). The most significant endpoint was the number of fragments that obtained 83% accuracy, 70% sensitivity, 90% specificity, and 0.82 AUC. Conclusion: We demonstrated that chromosome damage and cell proliferation rate could be significant biomarkers to predict late radiation proctitis. When these endpoints were used together in conjunction with a machine learning method, the better performance was obtained

  2. WE-D-BRE-05: Prediction of Late Radiation-Induced Proctitis in Prostate Cancer Patients Using Chromosome Aberration and Cell Proliferation Rate

    International Nuclear Information System (INIS)

    Purpose: Chromosome damage and cell proliferation rate have been investigated as potential biomarkers for the early prediction of late radiationinduced toxicity. Incorporating these endpoints, we explored the predictive power for late radiation proctitis using a machine learning method. Methods: Recently, Beaton et al. showed that chromosome aberration and cell proliferation rate could be used as biomarkers to predict late radiation proctitis (Beaton et al. (2013) Int J Rad Onc Biol Phys, 85:1346–1352). For the identification of radiosensitive biomarkers, blood samples were collected from 10 patients with grade 3 late proctitis along with 20 control patients with grade 0 proctitis. After irradiation at 6 Gy, statistically significant difference was observed between the two groups, using the number of dicentrics and excess fragments, and the number of cells in metaphase 2 (M2). However, Beaton et al. did not show the usefulness of combining these endpoints. We reanalyzed the dataset to investigate whether incorporating these endpoints can increase the predictive power of radiation proctitis, using a support vector machine (SVM). Results: Using the SVM method with the number of fragments and M2 endpoints, perfect classification was achieved. In addition, to avoid biased estimate of the classification method, leave-one-out cross-validation (LOO-CV) was performed. The best performance was achieved when all three endpoints were used with 87% accuracy, 90% sensitivity, 85% specificity, and 0.85 AUC (the area under the receiver operating characteristic (ROC) curve). The most significant endpoint was the number of fragments that obtained 83% accuracy, 70% sensitivity, 90% specificity, and 0.82 AUC. Conclusion: We demonstrated that chromosome damage and cell proliferation rate could be significant biomarkers to predict late radiation proctitis. When these endpoints were used together in conjunction with a machine learning method, the better performance was obtained

  3. Chromosomal aberrations as etiological factors of intrauterine growth retardation

    Directory of Open Access Journals (Sweden)

    Petrović Bojana

    2008-01-01

    Full Text Available Background/Aim. Intrauterine growth retardation (IUGR is a pathological condition of pregnancy characterised by birth weight below the 10th centile. A number of fetal, placental and maternal causes can lead to IUGR; although, in most cases no specific causes can be identified. The aim of this study was to determine the part of chromosomal abnormalities in IUGR etiology. Methods. Fetal blood karyotype taken by cordocentesis from 168 fetuses with diagnosed IUGR was analyzed. Results. Chromosomal rearrangements both numerical and structural were detected in 14 cases (12.2%. Two cases were triploid. Patau syndrome, Edwards syndrome and Down syndrome were found in two cases each. There was one case of trisomy 7 (47, XY, +7 and one case of trisomy 16 (47, XX, +16; one translocation, 46, XY, t (2; 14(q23; q32 and a deletion 46, XYdel (12 (p12 as well as two cases of sex chromosomes abnormalities, 45, X (Turner syndrome and 47, XYY. Conclusion. These findings suggest that a consistent number of symmetrical IUGR cases (about 12% can be associated with chromosomal rearrangements. Chromosomal aberrations that cause IUGR are heterogeneous, aberration of autosomes, mostly autosomal trisomies, being the most common.

  4. X-ray induction of mitotic and meiotic chromosome aberrations

    International Nuclear Information System (INIS)

    In 1964 six pairs of rat kangaroo (Potorous tridactylis) were obtained from Australia. The tissues of these animals were used to initiate cell lines. Since this species has a low chromosome number of six pairs, each pair with its own distinctive morphology, it is particularly favorable for cytogenetic research. In cell cultures derived from the corneal endothelial tissues of one animal there emerged a number of haploid cells. The number of haploid cells in the cultures reached as high as 20% of the total mitotic configurations. The in vitro diploid and haploid mixture cell cultures could be a resemblance or a coincidence to the mixture existence of the diploid primary spermatocytes and the haploid secondary spermatocytes (gametes) in the in vivo testicular tissues of the male animals. It would be interesting to compare reactions of the haploid and diploid cell mixture, either in the cultures or in the testes, to x-ray exposure. Two other studies involving x-ray effects on Chinese hamster oocyte maturation and meiotic chromosomes and the x-ray induction of Chinese hamster spermatocyte meiotic chromosome aberrations have been done in this laboratory. A review of these three studies involving diploid and haploid chromosomes may lead to further research in the x-ray induction of chromosome aberrations

  5. Long-term persistence of chromosome aberrations in uranium miners.

    Science.gov (United States)

    Mészáros, Gabriella; Bognár, Gabriella; Köteles, G J

    2004-07-01

    Chromosome aberration analyses were performed on blood samples from 165 active underground uranium miners between 1981 and 1985. After decommissioning the mine in 1997 chromosome aberration analyses were also included in the medical laboratory investigations of health conditions of 141 subjects between 1998 and 2002 within the framework of a follow-up-study. The numerical data are presented as functions of the exposure categories expressed in working level month up to 600. In the active groups the dicentric level was 7 to 12 times higher than in the unexposed population, the acentrics also higher with more than an order of magnitude, the frequency of total aberrations--including dicentrics, acentrics, rings, deletions, minits and numerical aberrations, i.e. both chromatid and chromosome type of aberrations were also well above the control level. In the group of former uranium miners although there were slight decreases in the dicentrics after 8 to 25 yr, the values were not significantly different from the values of active miners. The frequency of deletions was also maintained in the post-mining period. The frequency of acentrics, however, decreased significantly, but even the lowest values remained 2-3 times higher than the values in the unexposed population.The possibility is suggested that for the long-term persistence of cytogenetic alterations the permanent production and presence of clastogenic factors might be responsible. The comparison of the two datasets suggest a long-term persistence of cytogenetic alterations above the population average values in a large fraction of persons investigated. PMID:15308832

  6. Chromosome aberrations and environmental exposures in acute leukemia

    OpenAIRE

    Lindquist, Ragnhild Rosengren

    2009-01-01

    The aims of this thesis are to evaluate the role of environmental exposures, especially professional exposure to organic solvents and petroleum products in the etiology of acute leukemia and to investigate if there is a correlation between the exposure to a specific leukemogen factor and a clonal chromosome aberration of the leukemic cells. Papers I and II present results of a case-control study of environmental exposures, in all occupations during life-time, medical treatm...

  7. Long-term exposure to depleted uranium in Gulf-War veterans does not induce chromosome aberrations in peripheral blood lymphocytes.

    Science.gov (United States)

    Bakhmutsky, Marina V; Squibb, Katherine; McDiarmid, Melissa; Oliver, Marc; Tucker, James D

    2013-10-01

    Depleted uranium (DU) is a high-density heavy metal that has been used in munitions since the 1991 Gulf War. DU is weakly radioactive and chemically toxic, and long-term exposure may cause adverse health effects. This study evaluates genotoxic effects of exposure to DU by measuring chromosome damage in peripheral blood lymphocytes with fluorescence in situ hybridization whole-chromosome painting. Study participants are Gulf War-I Veterans with embedded DU fragments and/or inhalation exposure due to involvement in friendly-fire incidents; they are enrolled in a long-term health surveillance program at the Baltimore Veterans Administration Medical Center. Blood was drawn from 35 exposed male veterans aged 39 to 62 years. Chromosomes 1, 2, and 4 were painted red and chromosomes 3, 5, and 6 were simultaneously labeled green. At least 1800 metaphase cells per subject were scored. Univariate regression analyses were performed to evaluate the effects of log(urine uranium), age at time of blood draw, log(lifetime X-rays), pack-years smoked and alcohol use, against frequencies of cells with translocated chromosomes, dicentrics, acentric fragments, color junctions and abnormal cells. No significant relationships were observed between any cytogenetic endpoint and log(urine uranium) levels, smoking, or log(lifetime X-rays). Age at the time of blood draw showed significant relationships with all endpoints except for cells with acentric fragments. Translocation frequencies in these Veterans were all well within the normal range of published values for healthy control subjects from around the world. These results indicate that chronic exposure to DU does not induce significant levels of chromosome damage in these Veterans. PMID:23933231

  8. SYNAPTONEMAL COMPLEX DAMAGE IN RELATION TO MEIOTIC CHROMOSOME ABERRATIONS AFTER EXPOSURE OF MALE MICE TO CYCLOPHOSPHAMIDE (JOURNAL VERSION)

    Science.gov (United States)

    Cyclophosphamide (CP) has been reported to cause structural and numerical chromosome aberrations in mouse spermatocyte metaphase chromosomes. Further, it was concluded to be one of the few chemicals for which there appears to be reliable data suggesting that it can induce germ ce...

  9. The Level and Distribution of Chromosomal Aberration of Tomato Seeds at Different Penetration Depths of Carbon Ions

    Institute of Scientific and Technical Information of China (English)

    WANG Jufang; LI Wenjian; ZHANG Ying

    2008-01-01

    The relationship between the penetration depth and the level and distribution of chromosomal aberration of the root tip cells were investigated by exposure of the superposed tomato seeds to 80 MeV/u carbon ions. The results showed that on the entrance of the beam the chromosomal aberration level was low. Damage such as breaks and gaps were dominant. At the Bragg peak, the chromosomal aberration level was high. The yields of dicentrics, rings and disintegrated small chromosomes increased but the yields of breaks and gaps decreased. These results are consistent with the distribution of the physical depth dose profile of carbon ions. It is effective to deposit the Bragg peak on the seeds to induce hereditary aberration in the mutation breeding with heavy ions.

  10. Low Dose-Rate Effects on Chromosomal Aberrations in Workers Occupationally Exposed to Ionising Radiation

    International Nuclear Information System (INIS)

    Full text: Occupational exposure to ionising radiation can be assessed by chromosomal aberrations detected in peripheral blood lymphocytes. Blood samples were collected from 47 occupationally exposed individuals (X-ray diagnostic machines and industrial gamma defectoscopy). The chromosomal aberrations were analysed from at least 500 metaphases per person and their frequencies were compared with those obtained from 110 control individuals. It has been noticed the higher frequency of chromosomal aberrations in the exposed group related to the control. The increase was analysed according to the age groups (31-40, 41-50, and 51-60), sex and duration of employment. The higher frequency of dicentrics was not directly correlated with the age or duration of employment in the exposed group. The acentric fragments were encountered with much higher frequency in the exposed group. The chromosomal aberrations induced by low dose-rate in occupationally exposed people revealed the degree of individual sensitivity and the severity of the initial damage depending on the biological-pathological conditions. (author)

  11. Biological dosimetry of ionizing radiation by chromosomal aberration analysis

    International Nuclear Information System (INIS)

    Biological dosimetry consists of estimating absorbed doses for people exposed to radiation by mean biological methods. Several indicators used are based in haematological, biochemical, and cytogenetic data, although nowadays without doubt, the cytogenetic method is considered to be the most reliable. In this case, the study ol chromosomal aberrations, normally dicentric chromosomes, in peripheral lymphocytes can be related to absorbed dose through an experimental calibration curve. An experimental dose-response curve, using dicentric chromosomes analysis, X-rays at 300 kVp, 114 rad/min and temperature 37 degree celsius has been produced. Experimental data is fitted to model Y =α + β1D + β2D 2 , where Y is the number of dicentrics per cell and D the dose. The curve is compared with those produced elsewhere. (Author) 14 refs

  12. Chromosomal aberrations and SCEs as biomarkers of cancer risk

    DEFF Research Database (Denmark)

    Norppa, H; Bonassi, S; Hansteen, I-L; Hagmar, L; Strömberg, U; Rössner, P; Boffetta, P; Lindholm, C; Gundy, S; Lazutka, J; Cebulska-Wasilewska, A; Fabiánová, E; Srám, R J; Knudsen, Lisbeth E.; Barale, R; Fucic, A

    Previous studies have suggested that the frequency of chromosomal aberrations (CAs), but not of sister chromatid exchanges (SCEs), predicts cancer risk. We have further examined this relationship in European cohorts comprising altogether almost 22,000 subjects, in the framework of a European...... collaborative project (CancerRiskBiomarkers). The present paper gives an overview of some of the results of the project, especially as regards CAs and SCEs. The results confirm that a high level of CAs is associated with an increased risk of cancer and indicate that this association does not depend on the time...... between CA analysis and cancer detection, i.e., is obviously not explained by undetected cancer. The present evidence indicates that both chromatid-type and chromosome-type CAs predict cancer, even though some data suggest that chromosome-type CAs may have a more pronounced predictive value than chromatid...

  13. Human peripheral blood lymphocytes for the analysis of chromosome aberrations in mutagen tests

    International Nuclear Information System (INIS)

    Studies on exposed individuals, and on cultured cells, have shown that the human peripheral blood lymphocyte is an extremely sensitive indicator of both in vivo and in vitro induced chromosome structural change. These changes in chromosome structure offer readily scored morphological evidence of damage to the genetic material. Although problems exist in the extrapolation from in vitro results to the in vivo situation, the lymphocyte offers several advantages as a test system. The types of chromosome damage which can be cytologically distinguished at metaphase can be divided into two main groups: chromosome type and chromatid type. The circulating lymphocyte is in the G/sub 0/ or G/sub 1/ phase of mitosis and exposure to ionising radiations and certain other mutagenic agents during this stage produces chromosome-type damage where the unit of breakage and reunion is the whole chromosome (i.e. both chromatids at the same locus). However, cells exposed to these agents while in the S or G/sub 2/ stages of the cell cycle, after the chromosome has divided into two sister chromatids, yield chromatid-type aberrations and only the single chromatid is involved in breakage or exchange. Other agents (e.g. some of the alkylating agents) will usually produce only chromatid-type aberrations in cells in cycle although the cells are exposed to the mutagen whilst in G/sub 1/

  14. Chromosomal aberrations in Sigmodon hispidus from a Superfund site

    International Nuclear Information System (INIS)

    Cotton rats (Sigmodon hispidus) were collected from an EPA Superfund site located on an abandoned oil refinery. Three trapping grids were located on the refinery and three similar grids were located at uncontaminated localities which served as reference sites. Bone marrow metaphase chromosome preparations were examined for chromosomal damage. For each individual, 50 cells were scored for six classes of chromosomal lesions. For the fall 1991 trapping period, mean number of aberrant cells per individual was 2.33, 0.85, and 1.50 for the three Superfund grids., Mean number of aberrant cells per individual was 2.55, 2.55, and 2.12 from the reference grids. Mean number of lesions per cell was 2.77, 0.86, and 1.9 from the Superfund grids, and 3.55, 2.77, and 2.50 from the reference grids. For the spring 1992 trapping period, more damage was observed in animals from both Superfund and reference sites; however, animals from Superfund grids had more damage than animals from reference grids. Mean number of aberrant cells per individual was 3.50, 3.25, and 3.70 from the Superfund grids, and 2.40, 2.11, and 1.40 from the reference grids. Mean number of lesions per cell was 4.80, 4.25, and 5.50 from the Superfund grids, and 2.60, 2.33, and 1.50 from the reference grids. These data suggest animals may be more susceptible to chromosomal damage during winter months, and animals from the Superfund grids appear to be more severely affected than animals from reference grids

  15. In Vitro genotoxic and antigenotoxic studies of Thai Noni fruit juice by chromosomal aberration and sister chromatid exchange assays in human lymphocytes

    OpenAIRE

    Treetip Ratanavalachai; Sumon Thitiorul; Pranee Nandhasri

    2008-01-01

    The genotoxic and antigenotoxic effects of Noni fruit juice produced in Thailand have been studied in human lymphocytes for chromosome aberration assay and sister chromatid exchange (SCE) assay in vitro. Treatment of Noni fruit juice(3.1-50 mg/ml) alone for 3 h did not significantly induce chromosomal aberration or SCE (p

  16. A survey of chromosomal aberrations in lymphocytes of Chernobyl liquidators

    Energy Technology Data Exchange (ETDEWEB)

    Sevan`kaev, A.V.; Moiseenko, V.V.; Zhloba, A.A. [Medical Radiological Research Centre, Obninsk (Russian Federation); Lloyd, D.C.; Edwards, A.A. [National Radiological Protection Board, Chilton (United Kingdom); Braselmann, H. [G.S.F. Institut fuer Strahlenbiologie (Germany)

    1995-04-01

    Chromosomal aberrations in lymphocytes of 875 Chernobyl liquidators have been scored and by comparison with control subjects the dicentric plus ring and excess acentric fragment frequencies are higher for persons who worked in the exclusion zone in 1986-1988 but not in 1989. Aberration yields are too low for individual biological dosimetry but, after taking account of the time interval between irradiation and blood sampling, the dicentric plus ring frequencies indicate average doses for 1986, 1987 and 1989 in good agreement with the annual averages in the Obninsk Registry. For 1988 the cytogenetic data indicate a significant higher average dose than the Registry. Liquidators who were not issued with a personal film badge tend to have higher aberration yields than those for whom badge data are recorded. This is particularly evident for those persons who worked in the first three months after the accident where physical dosimetry data are less complete or reliable. The persons probably experienced the highest exposures of all liquidators and the chromosomal data suggest an average value of about 300 mGy. (author).

  17. Explanation of test and assessment of chromosomal aberrations on occupational health examinations for radiation workers

    International Nuclear Information System (INIS)

    Test and Assessment of Chromosomal Aberrations on Occupational Health Examinations for Radiation Workers was formulated for standardizing analysis and outcome assessment of chromosomal aberrations on occupational health examinations for radiation workers. In order to provide experimental and theoretical basis for implementation and extension of this standard, this paper interpreted the standard comprehensively, including some existed problems that methods on detection and outcome assessment of chromosomal aberrations is not unified in different laboratories in China, and related criteria,laws and regulations at home and abroad are not fit for the detection of chromosomal aberrations for radiation workers very well; some introduction on methods of chromosomal slide preparation, discriminant analysis and outcome assessment of chromosomal aberration; and some influencing factors in the quality of chromosomal aberration detection. (authors)

  18. Persistent chromosome aberrations in the somatic cells of A-bomb survivors, Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Current status of knowledge on the radiation-induced chromosome aberrations persisting since their induction in 1945 to date in the somatic cells of A-bomb survivors in Hiroshima and Nagasaki is reviewed. Dose-response relationship for chromosome aberration frequencies observed with the use of the old A-bomb dosimetry system (T65D) is also demonstrable based on the new dosimetry system (DS86). Despite the fact that the remarkable decrease in the amount of neutron component relative to the total dose in Hiroshima, there still exist inter-city differences in aberration frequency per unit dose both for kerma and bone marrow dose; the dose-square term is smaller in Hiroshima than in Nagasaki. The differential contribution of neutron radiation may be responsible in some part for the observed difference between Hiroshima and Nagasaki, although proof still remains to be obtained. There is a wide variability of the frequency of cells with chromosome aberrations between survivors within a given dose range. Random errors in the dose estimates assigned to individual survivors seem responsible, to a large extent, for the observed overdispersions in aberration frequencies in both cities. New molecular biology-oriented techniques to differentially stain specific chromosomes using fluorescence in situ hybridization with chromosome-specific composite DNA probes seem extremely promising for future rapid, accurate and extensive screening of reciprocal translocations observed predominantly in A-bomb survivors. Such data may be utilized to establish a better biological dosimetry system, especially for those persons who are irradiated in vivo many years before cytogenetic examinations. (author)

  19. Disruption of Maternal DNA Repair Increases Sperm-DerivedChromosomal Aberrations

    Energy Technology Data Exchange (ETDEWEB)

    Marchetti, Francesco; Essers, Jeroun; Kanaar, Roland; Wyrobek,Andrew J.

    2007-02-07

    The final weeks of male germ cell differentiation occur in aDNA repair-deficient environment and normal development depends on theability of the egg to repair DNA damage in the fertilizing sperm. Geneticdisruption of maternal DNA double-strand break repair pathways in micesignificantly increased the frequency of zygotes with chromosomalstructural aberrations after paternal exposure to ionizing radiation.These findings demonstrate that radiation-induced DNA sperm lesions arerepaired after fertilization by maternal factors and suggest that geneticvariation in maternal DNA repair can modulate the risk of early pregnancylosses and of children with chromosomal aberrations of paternalorigin.

  20. Adaptive response to and its time effect on radiation-induced chromosome aberrations in mouse embryonic cells pre-exposed to cadmium chloride

    International Nuclear Information System (INIS)

    Objective: To observe if cadmium chloride could induce cross adaptive response to and its time effect on cytogenetic damage of mouse embryonic cells caused by ionizing radiation. Methods: The mice were pre-treated with iv injection of cadmium chloride solution on gestation d 9, then they were exposed to 1.5 cGy 60Co γ-rays at different time intervals. Chromosome preparation was made on gestation d 10. Results: 0.25-2 mg Cd/kg body weight could induce resistance to cytogenetic damage of embryonic cells of mice caused by ionizing radiation and the adaptive response appeared 4 h after pre-exposure, at 8h reached the peak, but 12 to 24 h later synergism appeared. Conclusion: Cadmium chloride could induce cross adaptive response to 60Co γ-rays which had relations with time interval of ionizing radiation

  1. Retrospective chromosome aberration analysis of former uranium miners

    International Nuclear Information System (INIS)

    In this paper we present our data collected in the period of 1981-1985 on 165 persons exposed by different radon concentrations expressed in working level month (WLM) units from 100 up to 600. Following the decommissioning of the uranium mine in Hungary in 1997 cytogenetic status of 131 persons were within a follow-up-study of their health conditions initiated by the Hungarian Academy of Science. The persons have terminated their underground activities 5 to 20 years before testing. The comparison of the two datasets suggest a long-term persistence of cytogenetic alterations above the population average values in large percentages of persons investigated. The frequency of chromosome aberrations of uranium miners was found increased in function of their exposure to radon. The comparison of the miner's categories 20 years ago and in the recent years demonstrated the long-term existence of aberrations for many years after completion of underground mining activities. (authors)

  2. Numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and Arabidopsis thaliana

    OpenAIRE

    Ji, X.

    2014-01-01

    Numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and Arabidopsis thaliana. I studied numerical and structural chromosome aberrations in cauliflower (Brassica oleracea var. botrytis) and Arabidopsis thaliana. The large genomic changes are important for gene balance control, gene expression and regulation, and may affect the plant’s phenotype. Moreover, chromosome changes, in particular polyploidy, inversions and translocations play a signif...

  3. Track structure based modelling of chromosome aberrations after photon and alpha-particle irradiation.

    Science.gov (United States)

    Friedland, Werner; Kundrát, Pavel

    2013-08-30

    A computational model of radiation-induced chromosome aberrations in human cells within the PARTRAC Monte Carlo simulation framework is presented. The model starts from radiation-induced DNA damage assessed by overlapping radiation track structures with multi-scale DNA and chromatin models, ranging from DNA double-helix in atomic resolution to chromatin fibre loops, heterochromatic and euchromatic regions, and chromosome territories. The repair of DNA double-strand breaks via non-homologous end-joining is followed. Initial spatial distribution and complexity, diffusive motion, enzymatic processing, synapsis and ligation of individual DNA ends from the breaks are simulated. To enable scoring of different chromosome aberration types resulting from improper joining of DNA fragments, the repair module has been complemented by tracking the chromosome origin of the ligated fragments and the positions of centromeres. The modelled motion of DNA ends has sub-diffusive characteristics and corresponds to measured chromatin mobility within time-scales of a few hours. The calculated formation of dicentrics after photon and α-particle irradiation in human fibroblasts is compared to experimental data (Cornforth et al., 2002, Radiat Res 158, 43). The predicted yields of dicentrics overestimate the measurements by factors of five for γ-rays and two for α-particle irradiation. Nevertheless, the observed relative dependence on radiation dose is correctly reproduced. Calculated yields and size distributions of other aberration types are discussed. The present work represents a first mechanistic approach to chromosome aberrations and their kinetics, combining full track structure simulations with detailed models of chromatin and accounting for the kinetics of DNA repair. PMID:23811166

  4. Frequent induction of chromosomal aberrations in in vivo skin fibroblasts after allogeneic stem cell transplantation: hints to chromosomal instability after irradiation

    International Nuclear Information System (INIS)

    Total body irradiation (TBI) has been part of standard conditioning regimens before allogeneic stem cell transplantation for many years. Its effect on normal tissue in these patients has not been studied extensively. We studied the in vivo cytogenetic effects of TBI and high-dose chemotherapy on skin fibroblasts from 35 allogeneic stem cell transplantation (SCT) patients. Biopsies were obtained prospectively (n = 18 patients) before, 3 and 12 months after allogeneic SCT and retrospectively (n = 17 patients) 23–65 months after SCT for G-banded chromosome analysis. Chromosomal aberrations were detected in 2/18 patients (11 %) before allogeneic SCT, in 12/13 patients (92 %) after 3 months, in all patients after 12 months and in all patients in the retrospective group after allogeneic SCT. The percentage of aberrant cells was significantly higher at all times after allogeneic SCT compared to baseline analysis. Reciprocal translocations were the most common aberrations, but all other types of stable, structural chromosomal aberrations were also observed. Clonal aberrations were observed, but only in three cases they were detected in independently cultured flasks. A tendency to non-random clustering throughout the genome was observed. The percentage of aberrant cells was not different between patients with and without secondary malignancies in this study group. High-dose chemotherapy and TBI leads to severe chromosomal damage in skin fibroblasts of patients after SCT. Our long-term data suggest that this damage increases with time, possibly due to in vivo radiation-induced chromosomal instability

  5. Chromosome aberrations in workers of ignalina nuclear power plant

    International Nuclear Information System (INIS)

    Full text of publication follows: The Ignalina Nuclear Power Plant (I.N.P.P.) workers and outside workers including visitors constitute the largest occupational group exposed to low doses of ionizing radiation in Lithuania. In 2004, the annual collective dose to these workers (4392 persons) was 6,83 man Sv. The maximum annual individual dose of I.N.P.P. workers was 19,16 mSv, and of outside workers was 29,41 mSv. However, according to calculations performed by the Lithuanian Radiation Protection Centre, the decommissioning of I.N.P.P. (the I.N.P.P. is to be shut down by 2009) will result in collective dose of 35 man Sv. Therefore, a special attention should be given to implementation of radiation protection programme. The importance of cytogenetic studies in the medical surveillance of radiation-exposed persons is generally acknowledged. The aim of the present study was to analyse chromosome aberration frequencies in lymphocytes of I.N.P.P. workers. The blood sampling of 27 male workers was performed in October 2004, after planned outage of I.N.P.P.. It was estimated that outages of I.N.P.P. Units contributed 84% to all annual occupational collective dose. Average cumulative dose of 18 workers was 290,7 mSv (group A), and of 9 workers - 71,7 mSv (group B). The mean annual doses averaged over the three-year-period were 15,2 mSv and 0,76 mSv, respectively. None of the exposed workers had ever exceeded the permissible dose limit. The average age of group A workers was 45,2 years, and group B 48,2 years. A questionnaire form with details on age, occupational history, smoking habit and alcohol intake, medication, history of recent illness was completed for each person at the time of blood collection. 64 non-exposed male donors approximately matched by age were used as controls (group C). Heparinized venous blood samples were taken and cultures were initiated within 24 h according to the standard procedures. At least 500 first cycle metaphases were analysed from each

  6. Role of DNA polymerase α in chromosomal aberration production by ionizing radiation

    International Nuclear Information System (INIS)

    The authors have shown that aphidicolin, like other inhibitors of DNA synthesis, both induces chromosomal aberrations in human peripheral lymphocytes and, as a post-treatment, interacts synergistically with X rays to produce greatly enhanced aberration yields. Because DNA polymerase α is the only DNA-synthetic or repair enzyme known to be affected by aphidicolin, the authors infer that this enzyme is directly involved in the repair of DNA lesions which, if unrepaired, can result in visible chromosomal aberrations. The present experiments were undertaken to further explore the effects of aphidicolin in human lymphocytes in the post-DNA-synthetic G2 phase of the cell cycle. Earlier experiments in which cells were simply fixed at times after treatment when the frequency of metaphases in the DNA-synthetic S phase of the cell cycle is zero in typical percentage labeled mitoses curves for human lymphocytes did not completely rule out the possibility that the aberrations induced by aphidicolin actually arose in a small subpopulation of cells actually in the S phase, and not in G2 cells. Furthermore, the yield of X-ray-induced aberrations in G2 cells falls rapidly as a function of increasing irradiation-fixation interval, so comparisons of yields at particular fixation times can be misleading if the cells in each group do not progress through G2 at the same rate. The experiments reported here utilized labeling with tritiated thymidine to positively identify cells in the S phase at the time of treatment and serial Colcemid collections and fixations to determine aberration yields over as much of the G2 phase as feasible

  7. Modifying effect of reduced glutathione on X-ray-induced chromosome aberration and cell-cycle delay in muntjac lymphocytes in vitro

    International Nuclear Information System (INIS)

    Reduced glutathione treatment to unstimulated lymphocytes of Muntiacus muntjak 30 min prior to X-irradiation (2, 3 and 4 Gy) reduced the frequency of production of deletions in all the doses of X-ray and that of dicentrics and rings in 3- and 4-Gy exposed cultures. The consistency and degree of protection was more in the case of deletions than dicentrics and rings, and this may be correlated with the dominance in the production of deletions in the muntjac system which might probably be due to either the low chromosome number or a less efficient DNA repair. GSH pretreatment also reduced the radiation-induced cell-cycle delay in 2-Gy exposed cultures almost to the normal level of kinetics. (Auth.)

  8. The production of micronuclei from chromosome aberrations in irradiated cultures of human lymphocytes

    International Nuclear Information System (INIS)

    The characteristics of an assay for chromosomal damage - micronuclei produced in cultured human lymphocytes - are given together with the evidence that the assay accurately measures X-ray-induced chromosomal damage. In the experiments the response of lymphocytes from different donors was very uniform: (1) the increase in micronucleus frequency begins at the time of the first mitoses, 48 hours after the cultures are started, (2) the exponent of the dose response equation (y = kDsup(n)) was 1.2 for micronulei, (3) the frequency of micronuclei was decreased by a factor of about two when the dose was fractionated. The rejoining time for four of five donors was between 30 and 60 minutes, (4) the X-ray-induced micronucleus frequency in cells from people with Down's syndrome (trisomy-21) was twice that of control donors. Since the micronucleus assay reflects the aberration so well and is so fast, it is suitable for a rapid assessment of chromosomal damage

  9. The effects of exposure to different clastogens on the pattern of chromosomal aberrations detected by FISH whole chromosome painting in occupationally exposed individuals

    Energy Technology Data Exchange (ETDEWEB)

    Beskid, O. [Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 142 20 Prague 4 (Czech Republic); Dusek, Z. [Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 142 20 Prague 4 (Czech Republic); Solansky, I. [Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 142 20 Prague 4 (Czech Republic); Sram, R.J. [Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 142 20 Prague 4 (Czech Republic)]. E-mail: sram@biomed.cas.cz

    2006-02-22

    The pattern of chromosomal aberrations (CA) was studied by fluorescence in situ hybridization (FISH) technique (whole chromosomes 1 and 4 painting) in workers occupationally exposed to any of the four following conditions: acrylonitrile (ACN), ethyl benzene (EB), carcinogenic polycyclic aromatic hydrocarbons (c-PAHs), and irradiation in nuclear power plants (NPP), respectively. Decrease in the relative frequency of translocations was observed in EB group, and an increase in reciprocal translocations in ACN and NPP-exposed groups. An increase in a relative number of insertions was registered under all four conditions (significant at ACN, EB, c-PAHs, quasisignificant at NPP-exposed groups). Significant differences in the percentage of lymphocytes with aberrations on chromosome 1 (58.8 {+-} 32.7%, versus 73.8 {+-} 33.6% in the controls, P < 0.05), and chromosome 4 (47.0 {+-} 34.1%, versus 29.4 {+-} 32.2%, P < 0.01) were found in workers exposed to ACN. Similarly, a decrease in the proportion of cells with aberration on chromosome 1 (61.0 {+-} 24.0%, versus 73.8 {+-} 33.6%, P < 0.05) and an increase on chromosome 4 (45.6 {+-} 24.6%, versus 29.4 {+-} 32.2%, P < 0.05) were observed in workers exposed to EB. Frequency of aberrant cells (%AB.C.) as well as genomic frequency of translocations (F {sub G}/100) increased with age (P < 0.001). Aging also increased the percentage of translocations and reciprocal translocations (P < 0.05), but decreased the relative number of acentric fragments (P < 0.01). Smoking led to significantly increased F {sub G}/100 (P < 0.05), but did not affect the pattern of chromosomal aberrations. Our results seem to indicate that different carcinogens may induce a different pattern of chromosomal aberrations.

  10. Chromosomal Aberrations in Normal and AT Cells Exposed to High Dose of Low Dose Rate Irradiation

    Science.gov (United States)

    Kawata, T.; Shigematsu, N.; Kawaguchi, O.; Liu, C.; Furusawa, Y.; Hirayama, R.; George, K.; Cucinotta, F.

    2011-01-01

    Ataxia telangiectasia (A-T) is a human autosomally recessive syndrome characterized by cerebellar ataxia, telangiectases, immune dysfunction, and genomic instability, and high rate of cancer incidence. A-T cell lines are abnormally sensitive to agents that induce DNA double strand breaks, including ionizing radiation. The diverse clinical features in individuals affected by A-T and the complex cellular phenotypes are all linked to the functional inactivation of a single gene (AT mutated). It is well known that cells deficient in ATM show increased yields of both simple and complex chromosomal aberrations after high-dose-rate irradiation, but, less is known on how cells respond to low-dose-rate irradiation. It has been shown that AT cells contain a large number of unrejoined breaks after both low-dose-rate irradiation and high-dose-rate irradiation, however sensitivity for chromosomal aberrations at low-dose-rate are less often studied. To study how AT cells respond to low-dose-rate irradiation, we exposed confluent normal and AT fibroblast cells to up to 3 Gy of gamma-irradiation at a dose rate of 0.5 Gy/day and analyzed chromosomal aberrations in G0 using fusion PCC (Premature Chromosomal Condensation) technique. Giemsa staining showed that 1 Gy induces around 0.36 unrejoined fragments per cell in normal cells and around 1.35 fragments in AT cells, whereas 3Gy induces around 0.65 fragments in normal cells and around 3.3 fragments in AT cells. This result indicates that AT cells can rejoin breaks less effectively in G0 phase of the cell cycle? compared to normal cells. We also analyzed chromosomal exchanges in normal and AT cells after exposure to 3 Gy of low-dose-rate rays using a combination of G0 PCC and FISH techniques. Misrejoining was detected in the AT cells only? When cells irradiated with 3 Gy were subcultured and G2 chromosomal aberrations were analyzed using calyculin-A induced PCC technique, the yield of unrejoined breaks decreased in both normal and AT

  11. Frequency of unstable chromosome aberrations in peripheral lymphocytes of women with breast cancer treated with radiotherapy

    International Nuclear Information System (INIS)

    This study proposes to obtain information about the behavior of the frequency and distribution of radiation induced lymphocyte dicentric chromosome aberrations with therapeutic doses in women with breast cancer treated only with radiotherapy, about which there are no existing works in Chile. Blood samples were taken from 6 women volunteers included in the study, with their informed consent, treated in the Fundacion Arturo Lopez Perez, aged 24 to 65 years old, without prior or parallel chemotherapy, nor prior radiotherapy. Three peripheral blood samples were taken from each patient in 0, 16.2 and 43.2 Gy doses. The lymphocytes obtained from each sample were cultivated using the micro-culture technique following the protocol in IAEA Technical Report No. 405, 2001. The samples were evaluated under a microscope and the unstable chromosome aberrations for lymphocytes were counted. A total of 500 cells per sample was evaluated in most cases, which were distributed depending on the number of aberrations that they had. The results were analyzed by treatment dose for each of the study patients, using the Papworth u test, Dolphin's 'Contaminated Poisson' method and Sasaki's 'QDR'. Great variations were observed in the frequency distribution of aberrations among the patients studied, which could be due to the influence of factors related to the patients' partial irradiations (C.Wood)

  12. Interchromosomal distribution of gamma ray-induced chromatid aberrations in Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Inter chromosomal distributions of breakpoints from chromatid-type aberrations induced by gamma rays in Chinese hamster ovary cells were analyzed. In most chromosomes the distribution was as expected from chromosome lengths for simple breaks or the respective relative corrected length in case of exchanges. There were deviations from expectation in a few chromosomes for chromatid breaks, interchanges, intra-arm intra changes and inter-arm intra changes. Especially interesting are the results concerning chromosomes 2 and 8, which were more often involved in exchanges than expected. An 'exchange phenotype' for these chromosomes is proposed and possible explanations for the nonrandom distribution of chromosome breakpoints are presented. (author)

  13. Inter- and Intra-Chromosomal Aberrations in Human Cells Exposed in vitro to High and Low LET Radiations

    Science.gov (United States)

    Hada, M.; Wilkins, R.; Saganti, P. B.; Gersey, B.; Cucinotta, F. A.; Wu, H.

    2006-01-01

    Energetic heavy ions pose a health risk to astronauts in extended ISS and future Mars missions. High-LET heavy ions are particularly effective in causing various biological effects including cell inactivation, genetic mutations and cancer induction. Most of these biological endpoints are closely related to chromosomal damage, which can be utilized as a biomarker for radiation insults. Previously, we had studied chromosome aberrations in human lymphocytes and fibroblasts induced by both low- and high-LET radiation using FISH and multicolor fluorescence in situ hybridization (mFISH) techniques. In this study, we exposed human epithelial cells in vitro to gamma rays and energetic particles of varying types and energies and dose rates, and analyzed chromosomal damages using the multicolor banding in situ hybridization (mBAND) procedure. Confluent human epithelial cells (CH184B5F5/M10) were exposed to energetic heavy ions at NASA Space Radiation Laboratory (NSRL) at the Brookhaven National Laboratory, high energy neutron at the Los Alamos Nuclear Science Center (LANSCE) or Cs-137-gamma radiation source at the University of Texas, MD Anderson Cancer Center. After colcemid and Calyculin A treatment, cells were fixed and painted with XCyte3 mBAND kit (MetaSystems) and chromosome aberrations were analyzed with mBAND analysis system (MetaSystems). With this technique, individually painted chromosomal bands on one chromosome allowed the identification of interchromosomal aberrations (translocation to unpainted chromosomes) and intrachromosomal aberrations (inversions and deletions within a single painted chromosome). The results of the mBAND study showed a higher ratio of inversion involved with interchromosomal exchange in heavy ions compared to -ray irradiation. Analysis of chromosome aberrations using mBAND has the potential to provide useful information on human cell response to space-like radiation.

  14. Effect of cysteamine on chromosomal aberrations yield in gamma irradiated lymphocytes from human blood

    International Nuclear Information System (INIS)

    Cytogenetic analysis is made of lymphocyte cultures following in vitro gamma-irradiation of human whole venous blood with 93, 188, 372 and 448 rad from ''Rocos'' gamma-therapeutic apparatus, with or without chemical protection. The radioprotector - cysteamine - is added to the blood 15 minutes before irradiation in a dose of 200 micrograms per milliliter of blood. Lymphocyte cultures are fixed 52 hours after stimulation. No quantitative differences are found between the patterns of chromosomal anomalies induced in nonprotected and in protected lymphocyte cultures. There are less chromosomal fragments, dicentrics, interstitial deletions, rings and chromosomal interchanges, aberrant cells and breaks after irradiation in the presence of cysteamine. The protective effect varied depending on the radiation dose: very weak (18.4 per cent) after irradiation with 93 rad, increasing to 75.7 per cent after exposure to 448 rad. (A.B.)

  15. Analysis of the frequency of unstable chromosome aberrations in human lymphocytes irradiated with 60Co

    International Nuclear Information System (INIS)

    The aim of this study was to analyze the frequency of unstable chromosomal aberrations induced by gamma radiation from a 60Co source at two different doses. Samples were obtained from a healthy donor and exposed to 60Co source (Gammacel 220 ) located in the Department of Nuclear Energy of Pernambuco Federal University (DEN/UFPe/Brazil) with a rate of air Kerma to 3,277 Gy/h. Exposures resulted in absorbed dose 0.51 Gy and 0.77 Gy. Mitotic metaphases were obtained by culturing lymphocytes for chromosome analysis and the slides were stained with 5% Giemsa. Among the unstable chromosomal aberrations the dicentric chromosomes, ring chromosomes and acentric fragments were analyzed. To calculate the significance level the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. To calculate the significance level of the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. The results showed that there was significant difference of the frequencies of dicentric chromosomes (from 0.18 to 0.51 to 0.37 Gy to 0.77 Gy), however there was no statistically significant difference between the frequencies of acentric fragments ( 0.054 to 0, 51 Gy to 0.063 to 0.77 Gy) and ring chromosomes (0.001 to 0.51 Gy to 0.003 to 0.77 Gy). The low number of rings is found justified, considering that in irradiated human lymphocytes, its appearance is rare relative to dicentrics. The results confirm that dicentrics are the most reliable biomarkers in estimating dose after exposure to gamma radiation. These two points will make the calibration curve dose-response being built for Biological Dosimetry Laboratory of CRCN-NE/CNEN

  16. Nonhomologous DNA end joining and chromosome aberrations in human embryonic lung fibroblasts treated with environmental pollutants

    International Nuclear Information System (INIS)

    Highlights: • We analyzed the effect of air pollutants on NHEJ and chromosome aberrations. • In HEL12469 cells B[a]P and extractable organic matter induced DSBs. • The compounds induced XRCC4 expression and a weak Ku70/80 response. • We found increased frequency of aberrations of chromosomes 1, 2, 4, 5, 7 and 17. • The tested compounds preferentially affected chromosome 7. - Abstract: In order to evaluate the ability of a representative polycyclic aromatic hydrocarbon (PAH) and PAH-containing complex mixtures to induce double strand DNA breaks (DSBs) and repair of damaged DNA in human embryonic lung fibroblasts (HEL12469 cells), we investigated the effect of benzo[a]pyrene (B[a]P) and extractable organic matter (EOM) from ambient air particles <2.5 μm (PM2.5) on nonhomologous DNA end joining (NHEJ) and induction of stable chromosome aberrations (CAs). PM2.5 was collected in winter and summer 2011 in two Czech cities differing in levels and sources of air pollutants. The cells were treated for 24 h with the following concentrations of tested chemicals: B[a]P: 1 μM, 10 μM, 25 μM; EOMs: 1 μg/ml, 10 μg/ml, 25 μg/ml. We tested several endpoints representing key steps leading from DSBs to the formation of CAs including histone H2AX phosphorylation, levels of proteins Ku70, Ku80 and XRCC4 participating in NHEJ, in vitro ligation activity of nuclear extracts of the HEL12469 cells and the frequency of stable CAs assessed by whole chromosome painting of chromosomes 1, 2, 4, 5, 7 and 17 using fluorescence in situ hybridization. Our results show that 25 μM of B[a]P and most of the tested doses of EOMs induced DSBs as indicated by H2AX phosphorylation. DNA damage was accompanied by induction of XRCC4 expression and an increased frequency of CAs. Translocations most frequently affected chromosome 7. We observed only a weak induction of Ku70/80 expression as well as ligation activity of nuclear extracts. In summary, our data suggest the induction of DSBs and

  17. Chromosome Aberrations in Human Epithelial Cells Exposed Los Alamos High-Energy Secondary Neutrons: M-BAND Analysis

    Science.gov (United States)

    Hada, M.; Saganti, P. B.; Gersey, B.; Wilkins, R.; Cucinotta, F. A.; Wu, H.

    2007-01-01

    High-energy secondary neutrons, produced by the interaction of galactic cosmic rays (GCR) with the atmosphere, spacecraft structure and planetary surfaces, contribute a significant fraction to the dose equivalent radiation measurement in crew members and passengers of commercial aviation travel as well as astronauts in space missions. The Los Alamos Nuclear Science Center (LANSCE) neutron facility's 30L beam line (4FP30L-A/ICE House) is known to generate neutrons that simulate the secondary neutron spectrum of the Earth's atmosphere at high altitude. The neutron spectrum is also similar to that measured onboard spacecrafts like the MIR and the International Space Station (ISS). To evaluate the biological damage, we exposed human epithelial cells in vitro to the LANSCE neutron beams with an entrance dose rate of 2.5 cGy/hr, and studied the induction of chromosome aberrations that were identified with multicolor-banding in situ hybridization (mBAND) technique. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of inter-chromosomal aberrations (translocation to unpainted chromosomes) and intra-chromosomal aberrations (inversions and deletions within a single painted chromosome). Compared to our previous results with gamma-rays and 600 MeV/nucleon Fe ions of high dose rate at NSRL (NASA Space Radiation Laboratory at Brookhaven National Laboratory), the neutron data from the LANSCE experiments showed significantly higher frequency of chromosome aberrations. However, detailed analysis of the inversion type revealed that all of the three radiation types in the study induced a low incidence of simple inversions. Most of the inversions in gamma-ray irradiated samples were accompanied by other types of intrachromosomal aberrations but few inversions were accompanied by interchromosomal aberrations. In contrast, neutrons and Fe ions induced a significant fraction of inversions that involved complex rearrangements of both

  18. Induction of sister-chromatid exchanges and chromosome aberrations by γ-irradiated nucleic acid constituents in CHO cells

    International Nuclear Information System (INIS)

    Chinese hamster ovary (CHO) cells were exposed to different concentrations of hydrogen peroxide and to γ-irradiated, oxygenated solutions of thymine, thymidine and 2-deoxy-D-ribose. By using a modified Brd Zrd-labelling method sister-chromated exchanges (SCEs) and chromosomal aberrations were scored in the same cell population, one cycle after treatment. Irradiated, oxygenated solutions of 2-deoxy-D-ribose clearly induced SCEs and chromosomal aberrations. In comparison, hydrogen peroxide and irradiated solutions of thymine and thymidine were less effective in CHO cells. (orig.)

  19. The effect of 3-aminobenzamide on X-ray induction of chromosome aberrations in Down syndrome lymphocytes

    International Nuclear Information System (INIS)

    Human lymphocytes from normal and Down syndrome (DS) subjects were examined to determine the effect of 3-aminobenzamide (3AB) on X-ray-induced chromosome aberrations. Lymphocytes were treated with 150 or 300 rad of X-rays in the presence of 3 mM 3AB for various times after irradiation, and then the cells were analyzed for the presence of chromosome aberrations in mitotic cells. 3-Aminobenzamide had no effect on the frequency of chromosome aberrations as a result of treatment with X-rays in the presence of 3AB. These observations indicate that DS lymphocytes are more sensitive to the inhibition of poly(ADP)ribose synthetase than normal lymphocytes. (author). 44 refs.; 3 tabs

  20. Relationship of DNA lesions and their repair to chromosomal aberration production

    International Nuclear Information System (INIS)

    Recent work on the roles of specific kinds of DNA lesions and their enzymatic repair systems in the production of chromosomal aberrations seems consistent with a simple molecular model of chromosomal aberrations formation. Evidence from experiments with the human repair-deficient genetic diseases xeroderma pigmentosom, ataxia telangiectasia, and Fanconi's anemia is reviewed in the light of the contributions to aberration production of single and double polynucleotide strand breaks, base damage, polynucleotide strand crosslinks, and pyrimidine cyclobutane dimers

  1. Chromosomal Aberrations in DNA Repair Defective Cell Lines: Comparisons of Dose Rate and Radiation Quality

    Science.gov (United States)

    George, K. A.; Hada, M.; Patel, Z.; Huff, J.; Pluth, J. M.; Cucinotta, F. A.

    2009-01-01

    Chromosome aberration yields were assessed in DNA double-strand break repair (DSB) deficient cells after acute doses of gamma-rays or high-LET iron nuclei, or low dose-rate (0.018 Gy/hr) gamma-rays. We studied several cell lines including fibroblasts deficient in ATM (product of the gene that is mutated in ataxia telangiectasia patients) or NBS (product of the gene mutated in the Nijmegen breakage syndrome), and gliomablastoma cells that are proficient or lacking in DNA-dependent protein kinase, DNA-PK activity. Chromosomes were analyzed using the fluorescence in-situ hybridization (FISH) chromosome painting method in cells at the first division post-irradiation and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving >2 breaks in 2 or more chromosomes). Gamma radiation induced higher yields of both simple and complex exchanges in the DSB repair defective cells than in the normal cells. The quadratic dose-response terms for both chromosome exchange types were significantly higher for the ATM and NBS defective lines than for normal fibroblasts. However, the linear dose-response term was significantly higher only for simple exchanges in the NBS cells. Large increases in the quadratic dose response terms indicate the important roles of ATM and NBS in chromatin modifications that facilitate correct DSB repair and minimize aberration formation. Differences in the response of AT and NBS deficient cells at lower doses suggests important questions about the applicability of observations of radiation sensitivity at high dose to low dose exposures. For all iron nuclei irradiated cells, regression models preferred purely linear and quadratic dose responses for simple and complex exchanges, respectively. All the DNA repair defective cell lines had lower Relative biological effectiveness (RBE) values than normal cells, the lowest being for the DNA-PK-deficient cells, which was near unity. To further

  2. Chromosomal aberrations in mobile phone users in Tamilnadu, southern India

    International Nuclear Information System (INIS)

    Complete text of publication follows. Radiofrequency (RF) waves have long been used for different types of information exchange via the airwaves-wireless Morse code, radio, television, and wireless telephony. Increasingly larger numbers of people rely on mobile telephone technology, and health concerns about the associated RF exposure have been raised, particularly because the mobile phone handset operates in close proximity to the human body, and also because large numbers of base station antennas are required to provide widespread availability of service to large populations. In the present study chromosomal damage investigations were carried out on the peripheral blood lymphocytes of individuals using mobile phones, being exposed to MW frequency ranging from 800 to 2000 MHz. The aim of this study is to establish whether mobile phone use (n = 27) increases the frequency of chromosome aberrations (CA) in peripheral blood lymphocytes compared with controls (n = 27) in Tamilnadu, India. After signing a consent form, volunteers provided blood samples (5 ml) to establish cell cultures at 52 hrs. For CA analysis, 100 complete metaphase cells from each subject were evaluated. In the present study, in mobile phone users highly significant results were obtained when compared to control groups. These results highlight a correlation between mobile phone use (exposure to RFR) and genetic damage and require interim public health actions in the wake of widespread use of mobile telephony.

  3. Intra- and interindividual variability in lymphocyte chromosomal aberrations: implications for cancer risk assessment.

    Science.gov (United States)

    Peters, Susan; Portengen, Lützen; Bonassi, Stefano; Sram, Radim; Vermeulen, Roel

    2011-08-15

    Chromosomal aberration frequency in peripheral lymphocytes of healthy individuals has been found to be predictive of future cancer risk. The variability of chromosomal aberrations over time, which is largely unknown, should be clarified to interpret the strength of this association and to determine its use in cancer prediction. Intra- and interindividual variability in chromosomal aberration frequency was therefore determined. From a pooled database comprising 11 national cohorts (1965-2002), the authors included 9,433 blood samples from 3,550 subjects with at least one repeated chromosomal aberration measurement. The generalized concordance correlation coefficient of 0.19 was low, indicating high intraindividual variability compared with interindividual variability, resulting in a high likelihood of misclassification. The relation between chromosomal aberration frequency and future cancer risk has probably been underestimated in previous studies. A single chromosomal aberration measurement seems not to be representative of the whole lifespan level of chromosome instability and greatly limits the use of chromosomal aberration frequency-as measured with Giemsa staining-for individual risk assessment. PMID:21652601

  4. The effects of exposure to different clastogens on the pattern of chromosomal aberrations detected by FISH whole chromosome painting in occupationally exposed individuals

    International Nuclear Information System (INIS)

    The pattern of chromosomal aberrations (CA) was studied by fluorescence in situ hybridization (FISH) technique (whole chromosomes 1 and 4 painting) in workers occupationally exposed to any of the four following conditions: acrylonitrile (ACN), ethyl benzene (EB), carcinogenic polycyclic aromatic hydrocarbons (c-PAHs), and irradiation in nuclear power plants (NPP), respectively. Decrease in the relative frequency of translocations was observed in EB group, and an increase in reciprocal translocations in ACN and NPP-exposed groups. An increase in a relative number of insertions was registered under all four conditions (significant at ACN, EB, c-PAHs, quasisignificant at NPP-exposed groups). Significant differences in the percentage of lymphocytes with aberrations on chromosome 1 (58.8 ± 32.7%, versus 73.8 ± 33.6% in the controls, P G/100) increased with age (P G/100 (P < 0.05), but did not affect the pattern of chromosomal aberrations. Our results seem to indicate that different carcinogens may induce a different pattern of chromosomal aberrations

  5. Chromosome Aberrations in Normal and Ataxia-Telangiectasia Cells Exposed to Heavy Ions

    Science.gov (United States)

    Kawata, T.; Ito, H.; Liu, C.; Shigematsu, N.; George, K.; Cucinotta, F. A.

    2007-01-01

    Although cells derived from Ataxia Telangiectasia (AT) patients are known to exhibit abnormal responses to ionizing radiations, its underlying mechanism still remains unclear. Previously, the authors reported that at the same gamma-irradiation dose AT cells show higher frequencies of misrepair and deletions compared to normal human fibroblast cells. In this study, we investigated the effects of heavy ions beams on chromosomal aberrations in normal and AT cells. Normal and AT fibroblast cells arrested at G0/G1 phase were irradiated with 2 Gy of X-rays, 490 MeV/u Silicon (LET 55 keV/m), 500 MeV/u Iron (LET 185 keV/m) and 200 MeV/u Iron (LET 440 keV/m) particles, and then cells were allowed to repair for 24 hours at 37 degrees before subculture. Calyculin-A induced PCC method was employed to collect G2/M chromosomes and whole DNA probes 1 and 3 were used to analyze chromosomal aberrations such as color-junctions, deletions, simple exchanges (incomplete and reciprocal exanges) and complex-type exchanges. The percentages of aberrant cells were higher when normal and AT cells were exposed to heavy ions compared to X-rays, and had a tendency to increase with increasing LET up to 185 keV/m and then decreased at 440 keV/m. When the frequency of color-junctions per cell was compared after X-ray exposure, AT cells had around three times higher frequency of color-junctions (mis-rejoining) than normal cells. However, at 185 keV/m there was no difference in the frequency of color-junctions between two cell lines. It was also found that the frequency of simple exchanges per cell was almost constant in AT cells regardless LET levels, but it was LET dependent for normal cells. Interestingly, the frequency of simple exchanges was higher for AT cells when it was compared at 185 keV/m but AT cells had more complex-type exchanges at the same LET levels. Heavy ions are more efficient in inducing chromosome aberrations in normal and AT cells compared to X-rays, and the aberration types

  6. Using 3-color chromosome painting to decide between chromosome aberration models

    International Nuclear Information System (INIS)

    Ionizing radiation produces chromosome aberrations when DNA double strand breaks (DSB) interact pairwise. For more than 30 years there have been two main, competing theories of such binary DSB interactions. The classical theory asserts that an unrepaired DSB makes two ends which separate, with each end subsequently able to join any similar (non-telomeric) end. The exchange theory asserts that the two DSB ends remain associated until repair or a reciprocal chromosome exchange involving a second DSB occurs. The authors conducted an experiment to test these models, using 3-color chromosome painting. After in vitro irradiation of resting human lymphocytes, they observed cells with three-color triplets at first metaphase: three derivative chromosomes having permuted colors, as if three broken chromosomes had played musical chairs. On the exchange model in its standard form such 3-color triplets cannot occur. On the classical model the expected frequency can be calculated. They report data and computer calculations which exclude the exchange model and favor the classical model

  7. Chromosomal aberration analysis of persons occupationally exposed to radiation in Iran (2)

    International Nuclear Information System (INIS)

    The results of chromosome aberration analysis on lymphocytes from 333 persons suspected of being overexposed to X and gamma rays in recent years at Iran is presented. 91 persons were associated with industrial radiography, 124 with radiology and 118 with medical research and therapy centers. The total yields of chromosome aberration per 100 cells were respectively 3.76, 2.92 and 2.96. The frequencies of dicentrics which are important in biological dosimetry were respectively 0.18, 0.17 and 0.21. In this investigation, 50 subjects were also examined as control with a mean aberration of 1.14 per 100 cells. With regard to incidence of chromosome aberrations as mentioned, the rate of chromosome aberrations in industrial radiographers was the most significant

  8. Quantitative study of unstable chromosome aberrations following life time exposure of high background radiation in China

    International Nuclear Information System (INIS)

    Objective: To obtain a quantitative data regarding high background radiation-induced human chromosome aberrations by using advanced techniques. Methods: Environmental exposure dose for each individual was carefully measured. The estimated life-time doses ranged 25.2-244.8 and 5.4-51.7 mGy for individuals from the high background radiation area (HBRA) and the control area, respectively. Peripheral blood specimens were taken from 28 family members of three different generations in both areas. Purified lymphocyte culture technique for chromosome preparation was adopted and a total number of 70000 metaphases were scored. Results: In the case of HBRA, the frequencies of Dic + Rc increased with age, but no age-dependency was observed in subjects from the control area. The mean aberration yields significantly in excess of control value were seen in two older age groups. The aberration frequencies increased in proportion to the cumulative dose of the individuals living in HBRA. The estimated rate of increase per mGy was 1.5 x 10-5 per cell. Conclusion: It seems that Dic can continuously accumulated over life-time chronic low dose exposure and can serve as a reliable biological indicator. When the dose reduces to about 50 mGy, however, it becomes difficult to use to current method for quantitative analysis

  9. Evaluation of genotoxicity of Trois through Ames and in vitro chromosomal aberration tests

    Institute of Scientific and Technical Information of China (English)

    Manu Chaudhary; Anurag Payasi

    2013-01-01

    Objective: To investigate the mutagenic potential of Trois using the bacterial reverse mutation assay (Ames test) and in vitro chromosomal aberration test.Methods:typhimurium (TA 98, TA100, TA1535 and TA1537) and Escherichia coli (WP2 uvrA) with and without metabolic activation system (S9 mix) at the dose range of 313 to 5000 µg/plate. Chromosomal aberrations were evaluated in Chinese hamster lung (CHL) cell line at the dose levels of 15, 7.5, 3.7, 1.9 and 0.9 mg/mL in the absence and presence of S9 mix.Results:The ability of Trois to induce reverse mutations was evaluated in Salmonella Trois used in the study with and without S9 mix in all tester strains. Trois did not produce any structural aberration in CHL cells in the presence or absence of S9 mix. There were no increases in the number of revertant colonies at any concentrations of Conclusions: Results of this study suggest that Trois is non-mutagenic.

  10. The prevalence of chromosomal aberrations associated with myelodysplastic syndromes in China.

    Science.gov (United States)

    Hu, Qinyong; Chu, Yuxin; Song, Qibin; Yao, Yi; Yang, Weihong; Huang, Shiang

    2016-08-01

    This study aims to investigate the prevalence and distribution of diverse chromosomal aberrations associated with myelodysplastic syndromes (MDS) in China. Bone marrow samples were collected from multiple cities in China. Metaphase cytogenetic (MC) analysis and fluorescence in situ hybridization (FISH) were initially used to test chromosomal lesions. Affymetrix CytoScan 750 K genechip platform performed a genome-wide detection of chromosomal aberrations. Chromosomal gain was identified in 76 patients; the most prevalent was trisomy 8(17.9 %). New chromosomal gain was detected on chromosome 9, 19p, and X. Chromosomal loss was detected in 101 patients. The most frequent was loss 5q (21.0 %). Some loss and gain were not identified by MC or FISH but identified by genechip. UPD was solely identified by genechip in 51 patients; the most prevalent were UPD 7q (4.94 %) and UPD 17p (4.32 %). Furthermore, complex chromosomal aberrations were detected in 56 patients. In conclusion, Affymetrix CytoScan 750 K genechip was more precise than MC and FISH in detection of cryptic chromosomal aberrations relevant to MDS. Analysis of the prevalence and distribution of diverse chromosomal aberrations in China may improve strategies for MDS diagnosis and therapies. PMID:27225263

  11. Stable and unstable chromosomal aberrations in workers at nuclear waste repository

    International Nuclear Information System (INIS)

    A cytogenetic analysis of chromosomal aberrations was performed on 15 workers from final nuclear waste repository 'Novi Han'. The frequency of chromosomal aberrations were estimated in peripheral blood lymphocytes by conventional staining with Giemza and fluorescent in situ hybridization staining (FISH) using DNA specific probes. The results are compared with a control group from the administrative staff of the radioactive storage. All persons were interviewed by a special questionnaire list for professional, medical, and social status. The comparison of the results does not show increase of the frequency of unstable chromosomal aberrations detected by conventional staining. The frequency of stable chromosomal aberrations detected by FISH were significantly higher in workers group than in controls, although the statistical significance is low. The results show that FISH test is found to be more sensitive than conventional chromosomal analysis as a cytogenetic monitor test of the occupationally exposed subjects. (authors)

  12. Modifying influence of occupational inflammatory diseases on the level of chromosome aberrations in coal miners.

    Science.gov (United States)

    Volobaev, Valentin P; Sinitsky, Maxim Yu; Larionov, Aleksey V; Druzhinin, Vladimir G; Gafarov, Nikolay I; Minina, Varvara I; Kulemin, Jury E

    2016-03-01

    Coal miners are exposed to a wide range of genotoxic agents that can induce genome damage. In addition, miners are characterised by a high risk of the initiation of different occupational inflammatory as well as non-inflammatory diseases. The aim of this investigation is to analyse the modifying influence of occupational pulmonary inflammatory diseases on the level of chromosome aberrations (CAs) in miners working in underground coal mines in Kemerovo Region (Russian Federation). The study group included 90 coal miners with the following pulmonary diseases: chronic dust-induced bronchitis (CDB) and coal-workers' pneumoconiosis (CWP) (mean age = 53.52±2.95 years; mean work experience in coal-mining conditions = 27.70±3.61 years). As a population control (control 1), we have used venous blood extracted from 124 healthy unexposed men. The mean age in this group was 50.92±4.56 years. Control 2 was the venous blood extracted from 42 healthy coal miners (mean age = 51.56±6.38 years; mean work experience in coal-mining conditions = 25.43±8.14 years). We have discovered that coal miners are characterised by an increased general level of CAs as well as an increased frequency of several types of CAs. The significant increase in the frequency of aberration per 100 cells and aberration of chromosome type was discovered in the group of pulmonary disease patients (study group). No correlations of the level of chromosome damage with age, smoking status and work experience in coal-mining conditions were discovered. PMID:26609129

  13. Effects of colcemid concentration on chromosome aberration analysis in human lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kanda, Reiko; Hayata, Isamu; Kobayashi, Sadayoshi (National Inst. of Radiological Sciences, Chiba (Japan)); Jiang, Tao

    1994-03-01

    As a part of technical improvements of chromosome aberration analysis on human peripheral lymphocytes for biological radiation dosimetry, we examined the optimal conditions for the use of colcemid in chromosome preparation in order to obtain enough number of cells at metaphase in the first cell division. When treated with colcemid at concentrations below 0.01 [mu]g/ml from the beginning of culture, cultures harvested at 48 hours had low mitotic indices. Colcemid treatment at 0.025 to 0.05 [mu]g/ml during 48 hours resulted in high mitotic indices (8 to 15%) and almost of the mitotic cells remaining in the 1st cell division, suggesting that this range of colcemid concentration was appropriate for continuous treatment with colcemid. We further examined the effect of colcemid concentration on the quantitative consistency of the yields of radiation-induced chromosome aberration. Repeated experiments showed that the yield of dicentrics and centric rings in the culture having colcemid at 0.025 [mu]g/ml concentration were larger than that at 0.05 [mu]g/ml. These data indicate the importance of assuring the accuracy of colcemid concentration in the lymphocyte culture for cytogenetic radiation dosimetry. (author).

  14. Fishing for radiation quality: chromosome aberrations and the role of radiation track structure

    International Nuclear Information System (INIS)

    The yield of chromosome aberrations is not only dependent on dose but also on radiation quality, with high linear energy transfer (LET) typically having a greater biological effectiveness per unit dose than those of low-LET radiation. Differences in radiation track structure and cell morphology can also lead to quantitative differences in the spectra of the resulting chromosomal rearrangements, especially at low doses associated with typical human exposures. The development of combinatorial fluorescent labelling techniques (such as mFISH and mBAND) has helped to reveal the complexity of rearrangements, showing increasing complexity of observed rearrangements with increasing LET but has a resolution limited to ∼10 MBp. High-LET particles have not only been shown to produce clustered sites of DNA damage but also produce multiple correlated breaks along its path resulting in DNA fragments smaller than the resolution of these techniques. Additionally, studies have shown that the vast majority of radiation-induced HPRT mutations were also not detectable using fluorescent in situ hybridisation (FISH) techniques, with correlation of breaks along the track being reflected in the complexity of mutations, with intra- and inter-chromosomal insertions, and inversions occurring at the sites of some of the deletions. Therefore, the analysis of visible chromosomal rearrangements observed using current FISH techniques is likely to represent just the tip of the iceberg, considerably underestimating the extent and complexity of radiation induced rearrangements. (author)

  15. Fluorescence in situ hybridisation in chromosome aberration detection in subjects occupationally exposed to ionising radiation

    International Nuclear Information System (INIS)

    For more than two decades, chromosomal aberration analysis has been used to detect structural chromosomal aberrations as sensitive biodosimeters of occupational exposure to ionising radiation. Its use is also recommended by the World Health Organisation. Changes in chromosome structure detected by that method are considered to be early biomarkers of a possible malignant disease. Aberrations detected by the method are unstable and can be found in the lymphocytes of irradiated personnel only within a limited time after exposure. To detect stable chromosomal aberrations, which persist after exposure, multicolour fluorescent in situ hybridisation has to be used. Using DNA probes labelled with different fluorochromes, it dyes each pair of chromosomes with different colour. Due to the dynamic of unstable aberration formation, chromosomal aberration analysis is more suitable in genome damage assessment of recent exposures. On the other hand, fluorescence in situ hybridisation gives the information on chromosome instability caused by long-term occupational exposure to ionising radiation. Considering the high costs of fluorescence in situ hybridisation and the uncertainty of the result, it should be used in biodosimetry only when it is absolutely necessary.(author)

  16. Cyclin D1 splice site variant triggers chromosomal aberrations in healthy humans

    Czech Academy of Sciences Publication Activity Database

    Hemminki, K.; Mušák, L.; Vymetálková, Veronika; Šmerhovský, Z.; Halásová, E.; Osina, O.; Letková, L.; Försti, A.; Vodičková, Ludmila; Buchancová, J.; Vodička, Pavel

    2014-01-01

    Roč. 28, č. 3 (2014), s. 721-722. ISSN 0887-6924 Institutional support: RVO:68378041 Keywords : chromosomal aberrations * DNA repair Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 10.431, year: 2014

  17. Induction of chromosome aberrations in two lines of cultured cells using different types of radiation

    International Nuclear Information System (INIS)

    The induction of chromosome aberrations has been investigated in two lines of cultured cells for different types of radiation. The obtained results are compared with information on induction of cell reproductive death and malignant transformation. (Auth.)

  18. Clinicopathologic Study of Chromosomal Aberrations in Ocular Adnexal Lymphomas of Korean Patients

    OpenAIRE

    Choung, Hokyung; Kim, Young A; Kim, Namju; Lee, Min Joung; Khwarg, Sang In

    2015-01-01

    Purpose The incidence and clinical correlation of MALT1 translocation and chromosomal numerical aberrations in Korean patients with ocular adnexal mucosa associated lymphoid tissue (MALT) lymphoma have not yet been reported. We investigated the incidence and clinicopathologic relationship of these chromosomal aberrations in ocular adnexal MALT lymphomas in a Korean population. Methods Thirty ocular adnexal MALT lymphomas were investigated for the t(11;18) API2-MALT1, t(14;18) IgH-MALT1 transl...

  19. Chromosomal aberrations detected by comparative genomic hybridization technique (CGH in invasive ductal carcinoma of breast

    Directory of Open Access Journals (Sweden)

    Nooshiravanpour P

    2007-10-01

    Full Text Available Background: Nonlethal genetic damage is the basis for carcinogenesis. As various gene aberrations accumulate, malignant tumors are formed, regardless of whether the genetic damage is subtle or large enough to be distinguished in a karyotype. The study of chromosomal changes in tumor cells is important in the identification of oncogenes and tumor suppressor genes by molecular cloning of genes in the vicinity of chromosomal aberrations. Furthermore, some specific aberrations can be of great diagnostic and prognostic value. Comparative genomic hybridization (CGH is used to screen the entire genome for the detection and/or location chromosomal copy number changes.Methods: In this study, frozen sections of 20 primary breast tumors diagnosed as invasive ductal carcinoma from the Cancer Institute of Imam Khomeini Hospital, Tehran, Iran, were studied by CGH to detect chromosomal aberrations. We compared histopathological and immunohistochemical findings.Results: Hybridization in four of the cases was not optimal for CGH analysis and they were excluded from the study. DNA copy number changes were detected in 12 (75% of the remaining 16 cases. Twenty-one instances of chromosomal aberrations were detected in total, including: +1q, +17q, +8q, +20q, -13q, -11q, -22q, -1p, -16q, -8p. The most frequent were +1q, +17q, +8q, -13q, similar to other studies. In three cases, we detected -13q, which is associated with axillary lymph node metastasis and was reported in one previous study. The mean numbers of chromosomal aberrations per tumor in metastatic and nonmetastatic tumors was 1.5 and 1, respectively. No other association between detected chromosomal aberrations and histopathological and immunohistochemical findings were seen.Conclusion: Since intermediately to widely invasive carcinomas are more likely to have chromosomal aberrations, CGH can be a valuable prognostic tool. Furthermore, CGH can be used to detect targeting molecules within novel amplifications

  20. Routine laboratory diagnosis of chromosome aberrations in multiple myeloma

    Directory of Open Access Journals (Sweden)

    Yuet-Meng Chin

    2014-08-01

    Full Text Available Multiple Myeloma (MM is a Plasma Cell (PC malignancy characterized by proliferation of differentiated B cells mainly in the bone marrow. Genetic abnormalities are powerful prognostic factors in MM for risk stratification and therapeutic strategies. The standard diagnostic tests to detect genetic abnormalities in MM include Conventional Cytogenetic Analysis (CCA and Interphase Fluorescence In Situ Hybridization (FISH. Due to the low proliferative activity of the abnormal clone, only 30-50% of newly diagnosed MM demonstrate an abnormal karyotype by CCA. CCA is a biological test which requires dividing cells for analysis. The t(4;14 translocation which carries a poor prognosis is cryptic and cannot be detected by CCA. These limitations were overcome partly by the incorporation of interphase FISH as a routine diagnostic test in MM. There is an international consensus that FISH should be performed in all newly diagnosed MM to detect high-risk genetic abnormalities. FISH testing must be done on purified PCs or by simultaneous labeling of cytoplasmic immunoglobulin light chain to allow identification of PCs. The minimum essential abnormalities to test for are t(4;14, t(14;16 and del(17(p13. However, there is no consensus on the optimal protocol for CCA and interphase FISH. We review here the types of chromosomal aberrations found in MM, the prognostic significance of these abnormalities, methodologies in CCA to improve on the low yield of abnormal karyotypes, and protocols in interphase FISH. [Int J Res Med Sci 2014; 2(4.000: 1241-1247

  1. Chromosomal Aberrations Associated with Clonal Evolution and Leukemic Transformation in Fanconi Anemia: Clinical and Biological Implications

    OpenAIRE

    Stefan Meyer; Heidemarie Neitzel; Holger Tönnies

    2012-01-01

    Fanconi anaemia (FA) is an inherited disease with congenital and developmental abnormalities, bone marrow failure, and extreme risk of leukemic transformation. Bone marrow surveillance is an important part of the clinical management of FA and often reveals cytogenetic aberrations. Here, we review bone marrow findings in FA and discuss the clinical and biological implications of chromosomal aberrations associated with leukemic transformation.

  2. Cells bearing chromosome aberrations lacking one telomere are selectively blocked at the G2/M checkpoint

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Pilar [Unitat de Biologia Cel.lular, Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Barquinero, Joan Francesc [Unitat d' Antropologia Biologica, Departament de Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Duran, Assumpta [Unitat de Biologia Cel.lular, Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Caballin, Maria Rosa [Unitat d' Antropologia Biologica, Departament de Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Ribas, Montserrat [Servei de Radiofisica i Radioproteccio de l' Hospital de la Santa Creu i Sant Pau, 08025 Barcelona (Spain); Barrios, Leonardo, E-mail: Lleonard.Barrios@uab.cat [Unitat de Biologia Cel.lular, Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain)

    2009-11-02

    Cell cycle checkpoints are part of the cellular mechanisms to maintain genomic integrity. After ionizing radiation exposure, the cells can show delay or arrest in their progression through the cell cycle, as well as an activation of the DNA repair machinery in order to reduce the damage. The G2/M checkpoint prevents G2 cells entering mitosis until the DNA damage has been reduced. The present study evaluates which G0 radiation-induced chromosome aberrations are negatively selected in the G2/M checkpoint. For this purpose, peripheral blood samples were irradiated at 1 and 3 Gy of {gamma}-rays, and lymphocytes were cultured for 48 h. Calyculin-A and Colcemid were used to analyze, in the same slide, cells in G2 and M. Chromosome spreads were consecutively analyzed by solid stain, pancentromeric and pantelomeric FISH and mFISH. The results show that the frequency of incomplete chromosome elements, those lacking a telomeric signal at one end, decreases abruptly from G2 to M. This indicates that cells with incomplete chromosome elements can progress from G0 to G2, but at the G2/M checkpoint suffer a strong negative selection.

  3. Cells bearing chromosome aberrations lacking one telomere are selectively blocked at the G2/M checkpoint

    International Nuclear Information System (INIS)

    Cell cycle checkpoints are part of the cellular mechanisms to maintain genomic integrity. After ionizing radiation exposure, the cells can show delay or arrest in their progression through the cell cycle, as well as an activation of the DNA repair machinery in order to reduce the damage. The G2/M checkpoint prevents G2 cells entering mitosis until the DNA damage has been reduced. The present study evaluates which G0 radiation-induced chromosome aberrations are negatively selected in the G2/M checkpoint. For this purpose, peripheral blood samples were irradiated at 1 and 3 Gy of γ-rays, and lymphocytes were cultured for 48 h. Calyculin-A and Colcemid were used to analyze, in the same slide, cells in G2 and M. Chromosome spreads were consecutively analyzed by solid stain, pancentromeric and pantelomeric FISH and mFISH. The results show that the frequency of incomplete chromosome elements, those lacking a telomeric signal at one end, decreases abruptly from G2 to M. This indicates that cells with incomplete chromosome elements can progress from G0 to G2, but at the G2/M checkpoint suffer a strong negative selection.

  4. Cellular origin of prognostic chromosomal aberrations in AML patients

    DEFF Research Database (Denmark)

    Mora-Jensen, H.; Jendholm, J.; Rapin, N.;

    2015-01-01

    these aberrations occur in normal hematopoietic stem and progenitor cells (HSCs/HPCs) before definitive leukemic transformation through additional acquisition of a few (that is, mostly 1 or 2) leukemia-promoting driver aberrations. NGS studies on sorted bone marrow (BM) populations of AML patients with...... molecular aberrations that were present in the fully transformed committed HPCs together with the prognostic driver aberration. Adding to this vast heterogeneity and complexity of AML genomes and their clonal evolution, a recent study of a murine AML model demonstrated that t(9;11) AML originating from HSCs...

  5. γ-radiation induced chromosomal aberrations and alteration of gene expression in human peripheral blood lymphocyte show good correlation: implications in molecular biodosimetry

    International Nuclear Information System (INIS)

    Humans are at risk of exposure to ionizing radiation due to professional, diagnostic and therapeutic exposures. In addition, large scale exposures triggered either accidentally or by natural calamities or due to perceived terrorist threats are also possible. The median lethal dose of radiation (LD50/60, without medical intervention) for humans is quite low and is estimated to be 4.5 Gy. Due to this, it is imperative that biological dosimetry is conducted on all exposed or suspected-to-be exposed human population in shortest possible time for triage and appropriate medical intervention to save precious human lives. The 'gold standard' of contemporary biological dosimetry is dicentric assay (DCA) wherein dicentrics on chromosomes of human peripheral blood lymphocytes (HPBL) exposed to radiation is measured. At the present time it is considered as the reliable biomarkers of radiation exposure. However, DCA suffers from methodological limitation making applications of the technique practically impossible for a large number of samples in short time. In order to overcome this limitation of DCA, it is important to look for molecular biomarker of radiation exposure. In this study, it is our endeavor, to identify genes which correlate with radiation exposure to develop a reliable and sensitive molecular biodosimeter. Fresh human blood was exposed to 0.5, 1 and 2 of γ-rays (5.5 Gy min-1) and immediately subjected to DCA as well as DNA Microarray (Affymetrix Platform) and quantitative real-time PCR (qPCR). DNA Microarray revealed 20 early radiation response genes (RRGs) in HPBL exposed to γ-rays. Out of these, 8 genes, which showed dose response relationships, have been validated by qPCR at 0 and 24 h post-irradiation incubation periods using GAPDH and 18 S genes as normalizers. Simultaneous linear regression analysis of dose dependent DCA was performed for each gene, which exhibited good correlation. We do, however, see influence of inter-individual variability

  6. Induction of chromosome aberrations in Chinese hamster cells after heavy ion irradiation

    International Nuclear Information System (INIS)

    The induction of structural chromosome changes in V 79-Chinese hamster cells following heavy ion irradiation is studied. Asynchronous exponentially growing cells are exposed to the heavy ion beams at the Unilac, Darmstadt and the Ganil, Caen. The induction of chromosome aberrations was measured as a function of time after exposure. (orig./MG)

  7. Analysis of Chromosomal Aberrations after Low and High Dose Rate Gamma Irradiation in ATM or NBS Suppressed Human Fibroblast Cells

    Science.gov (United States)

    Hada, M.; Huff, J. L.; Patel, Z.; Pluth, J. M.; George, K. A.; Cucinotta, F. A.

    2009-01-01

    A detailed understanding of the biological effects of heavy nuclei is needed for space radiation protection and for cancer therapy. High-LET radiation produces more complex DNA lesions that may be non-repairable or that may require additional processing steps compared to endogenous DSBs, increasing the possibility of misrepair. Interplay between radiation sensitivity, dose, and radiation quality has not been studied extensively. Previously we studied chromosome aberrations induced by low- and high- LET radiation in several cell lines deficient in ATM (ataxia telangactasia mutated; product of the gene that is mutated in ataxia telangiectasia patients) or NBS (nibrin; product of the gene mutated in the Nijmegen breakage syndrome), and gliomablastoma cells that are proficient or lacking in DNA-dependent protein kinase (DNA-PK) activity. We found that the yields of both simple and complex chromosomal aberrations were significantly increased in the DSB repair defective cells compared to normal cells. The increased aberrations observed for the ATM and NBS defective lines was due to a significantly larger quadratic dose-response term compared to normal fibroblasts for both simple and complex aberrations, while the linear dose-response term was significantly higher in NBS cells only for simple exchanges. These results point to the importance of the functions of ATM and NBS in chromatin modifications that function to facilitate correct DSB repair and minimize aberration formation. To further understand the sensitivity differences that were observed in ATM and NBS deficient cells, in this study, chromosomal aberration analysis was performed in normal lung fibroblast cells treated with KU-55933, a specific ATM kinase inhibitor, or Mirin, an MRN complex inhibitor involved in activation of ATM. We are also testing siRNA knockdown of these proteins. Normal and ATM or NBS suppressed cells were irradiated with gamma-rays and chromosomes were collected with a premature chromosome

  8. Dose-response relationship of neutron and gamma rays to chromosomally aberrant cells among atomic bomb survivors in Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    The quantitative relationship of the frequency of cells with radiation-induced chromosome aberrations in peripheral leukocytes in atomic bomb survivors has been evaluated as a function of gamma and neutron doses. Three different models have been examined; each assumes a linear or a non-linear response to gamma rays and a linear-response to neutrons. From the standpoint of the goodness of fit of these models, the model which ''best'' fits the data on the frequency of cells with radiation-induced chromosome aberrations is the exponent model, where the frequency of aberrant cells increases exponentially with dose. The goodness of fit for this model shows the frequencies of cells with any chromosome aberration or an exchange aberration to be dependent cubically on the gamma ray dose and linearly on the neutron dose. The result derived from the frequency of aberrant cells gives a conservative dose-response relationship. The relative biological effectiveness of neutrons for frequency of cells with any chromosome aberration is calculated to be 13 at 30 rad of neutrons, 6 at 100 rad, 3 at 300 rad and so on. (author)

  9. Frequencies of chromosomal aberrations and sister chromatid exchanges in the benthic worm Neanthes arenaceodentata exposed to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, F.L.; Rice, D.W. Jr., Moore, D.H.

    1984-07-01

    Traditional bioassays are unsuitable for assessing sublethal effects from ocean disposal of low-level radioactive waste because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration and sister chromatid exchange (SCE) induction as measures of low-level radiation effects in a sediment-dwelling marine worm, Neanthes arenaceodentata. The SCEs, in contrast to chromosomal aberrations, do not alter the overall chromosome morphology and in mammalian cells appear to be a more sensitive indicator of DNA alterations caused by environmental mutagens. Newly hatched larvae were exposed to two radiation-exposure regimes of either x rays at a high dose rate of 0.7 Gy (70 rad)/min for as long as 5.5 min or to /sup 60/Co gamma rays at a low dose rate of from 4.8 x 10/sup -5/ to 1.2 x 10/sup -1/ Gy (0.0048 to 12 rad)/h for 24 h. After irradiation, the larvae were exposed to 3 x 10/sup -5/M bromodeoxyuridine (BrdUrd) for 28 h (x-ray-irradiated larvae) or for 54 h (/sup 60/Co-irradiated larvae). Larval cells were examined for the proportion of cells in first, second, and third or greater division. Frequencies of chromosomal aberrations and SCEs were determined in first and second division cells, respectively. Results from x-ray irradiation indicated that dose-related increases occur in chromosome and chromatid deletions, but a dose of equal or greater 2 Gy (equal to or greater than 200 rad) was required to observe a significant increase. Worm larvae receiving /sup 60/Co irradiation showed elevated SCE frequencies with a significant increase of 0.6 Gy (60 rad). We suggest that both SCEs and chromosomal aberrations may be useful for measuring effects on genetic material induced by radiation. 56 references, 7 figures, 9 tables.

  10. Frequencies of chromosomal aberrations and sister chromatid exchanges in the benthic worm Neanthes arenaceodentata exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Traditional bioassays are unsuitable for assessing sublethal effects from ocean disposal of low-level radioactive waste because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration and sister chromatid exchange (SCE) induction as measures of low-level radiation effects in a sediment-dwelling marine worm, Neanthes arenaceodentata. The SCEs, in contrast to chromosomal aberrations, do not alter the overall chromosome morphology and in mammalian cells appear to be a more sensitive indicator of DNA alterations caused by environmental mutagens. Newly hatched larvae were exposed to two radiation-exposure regimes of either x rays at a high dose rate of 0.7 Gy (70 rad)/min for as long as 5.5 min or to 60Co gamma rays at a low dose rate of from 4.8 x 10-5 to 1.2 x 10-1 Gy (0.0048 to 12 rad)/h for 24 h. After irradiation, the larvae were exposed to 3 x 10-5M bromodeoxyuridine (BrdUrd) for 28 h (x-ray-irradiated larvae) or for 54 h (60Co-irradiated larvae). Larval cells were examined for the proportion of cells in first, second, and third or greater division. Frequencies of chromosomal aberrations and SCEs were determined in first and second division cells, respectively. Results from x-ray irradiation indicated that dose-related increases occur in chromosome and chromatid deletions, but a dose of equal or greater 2 Gy (equal to or greater than 200 rad) was required to observe a significant increase. Worm larvae receiving 60Co irradiation showed elevated SCE frequencies with a significant increase of 0.6 Gy (60 rad). We suggest that both SCEs and chromosomal aberrations may be useful for measuring effects on genetic material induced by radiation. 56 references, 7 figures, 9 tables

  11. Flow cytometric analysis of chromosome damage after irradiation: Relation to chromosome aberrations and cell survival

    International Nuclear Information System (INIS)

    Reproductive death of cultured cells is commonly assessed by measurement of clonogenic capacity which requires a culture period equivalent to about ten cell doubling times. Chromosome structural changes can be observed microscopically in stained preparations of mitotic cells but this requires tedious counting. For a rapid determination of cellular sensitivity which might provide predictions of responses of tumors to various treatments, a new technique would be valuable if the dependence of responses on dose and radiation quality would correlate well with other cellular responses. Flow cytometry has provided a technique for the rapid determination of DNA content of individual chromosomes of mammalian cells and of changes induced by various treatments. This technique involves selection of mitotic cells, the preparation of mono-disperse chromosome suspensions, measurement of DNA content histograms and the analysis of these histograms by a computer program

  12. Role of fertilized eggs in the formation of chromosome aberrations in mutagen-treated germ cells of male mice

    International Nuclear Information System (INIS)

    The processes in somatic cells that lead to the formation and transmission of aberrations are not necessarily the same as in germ cells. This point is illustrated by demonstrating two phenomena in mice that are unique in certain germ cell stages. Information to date strongly indicates the presence of two different processes in fertilized eggs that affect the yield of aberrations, qualitatively and quantitatively, following chemical treatment of meiotic and postmeiotic male germ cells. First, if the reaction products are intact in the male chromosomes at the time of sperm entry, they may be repaired in fertilized eggs. If repair is not affected and the lesions persist to the time of pronuclear chromosome replication, they are expected to lead to chromatid-type aberrations and eventually to dominant-lethality. Second, if the reaction products are transformed into suitable intermediate lesions, before the sperm enters the egg, the fertilized egg can affect chromosome exchange. These two processes in fertilized eggs to not affect aberration formation in chemically treated male premeiotic stages. While the repair process does not seem to affect x-ray-induced lesions present in the fertilizing sperm, no information is yet available in the mouse on whether or not the exchange process following exposure of male meiotic and postmeiotic germ cells also takes place after sperm entry

  13. Simulation of the Formation of DNA Double Strand Breaks and Chromosome Aberrations in Irradiated Cells

    Science.gov (United States)

    Plante, Ianik; Ponomarev, Artem L.; Wu, Honglu; Blattnig, Steve; George, Kerry

    2014-01-01

    The formation of DNA double-strand breaks (DSBs) and chromosome aberrations is an important consequence of ionizing radiation. To simulate DNA double-strand breaks and the formation of chromosome aberrations, we have recently merged the codes RITRACKS (Relativistic Ion Tracks) and NASARTI (NASA Radiation Track Image). The program RITRACKS is a stochastic code developed to simulate detailed event-by-event radiation track structure: [1] This code is used to calculate the dose in voxels of 20 nm, in a volume containing simulated chromosomes, [2] The number of tracks in the volume is calculated for each simulation by sampling a Poisson distribution, with the distribution parameter obtained from the irradiation dose, ion type and energy. The program NASARTI generates the chromosomes present in a cell nucleus by random walks of 20 nm, corresponding to the size of the dose voxels, [3] The generated chromosomes are located within domains which may intertwine, and [4] Each segment of the random walks corresponds to approx. 2,000 DNA base pairs. NASARTI uses pre-calculated dose at each voxel to calculate the probability of DNA damage at each random walk segment. Using the location of double-strand breaks, possible rejoining between damaged segments is evaluated. This yields various types of chromosomes aberrations, including deletions, inversions, exchanges, etc. By performing the calculations using various types of radiations, it will be possible to obtain relative biological effectiveness (RBE) values for several types of chromosome aberrations.

  14. Why it is crucial to analyze non clonal chromosome aberrations or NCCAs?

    Science.gov (United States)

    Heng, Henry H Q; Regan, Sarah M; Liu, Guo; Ye, Christine J

    2016-01-01

    Current cytogenetics has largely focused its efforts on the identification of recurrent karyotypic alterations, also known as clonal chromosomal aberrations (CCAs). The rationale of doing so seems simple: recurrent genetic changes are relevant for diseases or specific physiological conditions, while non clonal chromosome aberrations (NCCAs) are insignificant genetic background or noise. However, in reality, the vast majority of chromosomal alterations are NCCAs, and it is challenging to identify commonly shared CCAs in most solid tumors. Furthermore, the karyotype, rather than genes, represents the system inheritance, or blueprint, and each NCCA represents an altered genome system. These realizations underscore the importance of the re-evaluation of NCCAs in cytogenetic analyses. In this concept article, we briefly review the definition of NCCAs, some historical misconceptions about them, and why NCCAs are not insignificant "noise," but rather a highly significant feature of the cellular population for providing genome heterogeneity and complexity, representing one important form of fuzzy inheritance. The frequencies of NCCAs also represent an index to measure both internally- and environmentally-induced genome instability. Additionally, the NCCA/CCA cycle is associated with macro- and micro-cellular evolution. Lastly, elevated NCCAs are observed in many disease/illness conditions. Considering all of these factors, we call for the immediate action of studying and reporting NCCAs. Specifically, effort is needed to characterize and compare different types of NCCAs, to define their baseline in various tissues, to develop methods to access mitotic cells, to re-examine/interpret the NCCAs data, and to develop an NCCA database. PMID:26877768

  15. Genotoxic and antigenotoxic effects of Fucus vesiculosus extract on cultured human lymphocytes using the chromosome aberration and Comet assays

    Directory of Open Access Journals (Sweden)

    Cleide Leite-Silva

    2007-01-01

    Full Text Available The brown seaweed Fucus vesiculosus (Fucales, Fucaceae was screened for its protective activity using doxorubicin-induced DNA damage in human lymphocytes. In this study, we assessed the genotoxic and antigenotoxic potential of three different concentrations (0.25, 0.5 and 1.0 mg mL-1 of F. vesiculosus aqueous extract using the chromosome aberration and Comet assays. Treatment of human lymphocyte cultures with 0.25, 0.5 and 1.0 mg mL-1 F. vesiculosus aqueous extract had no effect on the chromosome aberration frequency or on the extent of DNA damage detected by the Comet assay. The antigenotoxic effects of the extract were tested in human lymphocyte cultures treated with 15 µg mL-1 of doxorubicin, either alone or combined with the different concentrations of the extract, which was added to the cultures before, simultaneously with or after the doxorubicin. Only when lymphocytes were pre-treated with extract there was a reduction in doxorubicin-induced chromosome aberrations and DNA damage as detected by the Comet assay. These results demonstrate that F. vesiculosus aqueous extract is not genotoxic in cultured human lymphocytes and indicate that when added to lymphocyte cultures before doxorubicin it has antigenotoxic activity against doxorubicin-induced DNA damage.

  16. Management of cisplatin toxicity and chromosomal aberration by vitamin E in male rats

    International Nuclear Information System (INIS)

    Cisplatin is one of the most active antineoplastic drugs showing a broad therapeutic activity spectrum against different types of human neoplasms. To elvaute the subacute toxicity of the drug and to test the probable preventive effect of vitamin E in rats, forty-eight male albino rats were used in this study. Animals were classified into four groups, control, vitamin E, cisplatin and vitamin E with cisplatin. Vitamin E was administered orally at a dose of 2 mg/rat for two weeks prior to cisplatin intraperitoneal injection (5 mg/kg as a single dose) and then administration of vitamin E which was continued for two another weeks (end of experiment). The changes in body weight, counts of RBC and WBC, lipid peroxide, Na+, K+, chromosomal aberration and aldosterone hormone were recorded. Cisplatin administration caused 57.4% and 60% mortality at 3 and 5 weeks intervals. Regular intake of vitamin E induced significant role against the physiological disorders and chromosomal alterations occurred after cisplatin drug administration. The present study is directed to demonstrate the toxic effect of cisplatin on mortality, body weight, blood cells, aldosterone hormone, lipid peroxidation, Na+, K+, urea, creatinia as well as on chromosomal pattern and the efficacy of vitamin E in modulating cisplatin toxicity

  17. The Induction of Chromosome Aberrations and Micronuclei in Human Peripheral Blood Lymphocytes at Low Doses of Radiation

    CERN Document Server

    Shmakova, N L; Krasavin, E A; Melnikova, L A; Fadeeva, T A

    2003-01-01

    The chromosome damage induced by the low doses of gamma-irradiation with ^{60}Co and X-rays in peripheral blood lymphocytes has been studied using different cytogenetic assays. Isolated lymphocytes were exposed to 0.01-1.0 Gy, simulated by PHA, and analysed for chromosome aberrations by the metaphase and the anaphase methods, by the micronucleus assay. Despite the quantitative differences in the amount of chromosome damage revealed by different methods, all of them demonstrated complex nonlinear dose dependence of the frequency of aberrant cells and aberrations. At the dose range of 0.01-0.05 Gy the cells showed the highest radiosensitivity; at 0.05-0.5 Gy the dose-independent induction of chromosome damage was revealed. At the doses of 0.5-1.0 Gy the dose-effect curves became linear with the decreased slope compared with the initial one (by a factor of 5 to 10 for different criteria) reflecting a higher radioresistance of the cells. These data confirm the idea that the direct linear extrapolation of high-dos...

  18. M-BAND Analysis of Chromosome Aberration In Human Epithelial Cells exposed to Gamma-ray and Secondary Neutrons of Low Dose Rate

    Science.gov (United States)

    Hada, M.; Saganti, P. B.; Gersey, B.; Wilkins, R.; Cucinotta, F. A.; Wu, H.

    2007-01-01

    High-energy secondary neutrons, produced by the interaction of galactic cosmic rays with the atmosphere, spacecraft structure and planetary surfaces, contribute to a significant fraction to the dose equivalent in crew members and passengers during commercial aviation travel, and astronauts in space missions. The Los Alamos Nuclear Science Center (LANSCE) neutron facility's "30L" beam line is known to generate neutrons that simulate the secondary neutron spectrum of the Earth's atmosphere at high altitude. The neutron spectrum is also similar to that measured onboard spacecraft like the MIR and the International Space Station (ISS). To evaluate the biological damage, we exposed human epithelial cells in vitro to the LANSCE neutron beams at an entrance dose rate of 2.5 cGy/hr or gamma-ray at 1.7cGy/hr, and assessed the induction of chromosome aberrations that were identified with mBAND. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of inter-chromosomal aberrations (translocation to unpainted chromosomes) and intra-chromosomal aberrations (inversions and deletions within a single painted chromosome). Compared to our previous results for gamma-rays and 600 MeV/nucleon Fe ions of high dose rate, the neutron data showed a higher frequency of chromosome aberrations. However, detailed analysis of the inversion type revealed that all of the three radiation types in the study induced a low incidence of simple inversions. The low dose rate gamma-rays induced a lower frequency of chromosome aberrations than high dose rate gamma-rays, but the inversion spectrum was similar for the same cytotoxic effect. The distribution of damage sites on chromosome 3 for different radiation types will also be discussed.

  19. Some thoughts on the nature of chromosomal aberrations and their use as a quantitative end-point for radiobiological studies

    International Nuclear Information System (INIS)

    A vital condition when chromosomal aberrations are to be used as a quantitative end-point (e.g. for constructing a dose response curve) is that a specific dose must produce a specific yield of aberrations under a given set of experimental conditions. In practice, there are very few cell systems where this condition is met. The majority show significant variations in observed yield with time between irradiation and sampling, indicative of variable radiosensitivity within the cell population. The profile of this yield time curve is determined by the cell-cycle kinetics and therefore is itself subject to modification by radiation through mitotic delay and perturbation. Thus in such heterogeneous populations, each increment of dose not only induces more aberrations, but at the same time modifies the recovered yield per cell. This has an obvious bearing upon the interpretation of the shape of any dose-response curve obtained

  20. Cytogenetic biological dosimetry in radiological protection: chromosome aberration analysis in human lymphocyties

    International Nuclear Information System (INIS)

    The effects of ionizing radiation on chromosomes have been know for several decades and dose effect relationships are also fairly well established for several doses and dose rates. Apart from its biological significance, the interpretation of chromosome aberration frequency associated with human exposure to radiation plays an important role in dose assessment, particularly in cases where exposure is though to have occurred but no physical dose monitoring system was present. Based on the cytogenetic data obtained from seven cases of exposure to radiation the aberration frequency have been fitted to the quadratic function Y= αD + βD2 as the dose response curves from literature. The dose equivalent estimate by frequency of chromosomic aberration found here was compared with 60Co and 192Ir already published curves obtained at almost similar dose rate together with some hematological data. (author)

  1. Effect of epithalon on the incidence of chromosome aberrations in senescence-accelerated mice.

    Science.gov (United States)

    Rosenfeld, S V; Togo, E F; Mikheev, V S; Popovich, I G; Khavinson, V Kh; Anisimov, V N

    2002-03-01

    The incidence of chromosome aberrations in bone marrow cells of 12-month-old SAMP-1 female mice characterized by accelerated aging was 1.8 times higher than in wild-type SAMR-1 females and 2.2 times higher than in SHR females of the same age. Treatment with Epithalon (Ala-Glu-Asp-Gly) starting from the age of 2 months decreased the incidence of chromosome aberrations in SAMP-1, SAMR-1, and SHR mice by 20%, 30.1%, and 17.9%, respectively, compared to age-matched controls (p<0.05). Treatment with melatonin (given with drinking water in a dose of 20 mg/liter in night hours) had no effect on the incidence of chromosome aberrations in SHR mice. These data indicate antimutagenic effect of Epithalon, which probably underlies the geroprotective effect of this peptide. PMID:12360351

  2. Chromosome aberration assays in Pisum for the study of environmental mutagens.

    Science.gov (United States)

    Grant, W F; Owens, E T

    2001-05-01

    From a literature survey, 117 chemicals are tabulated that have been assayed in 179 assays for their clastogenic effects in Pisum. Of the 117 chemicals that have been assayed, 65 are reported at giving a positive reaction (i.e. causing chromosome aberrations), 30 positive with a dose response, five borderline positive. Seventeen chemicals gave a negative response. Eighty-one percent of the chemicals gave a definite positive response. A c-mitotic effect was detected from treatment with 17 chemicals. In addition to the above tabulation of chemicals, 39 chemicals have been reported with an antimitotic effect. Thirteen assays have been recorded for five types of radiation, which with the exception of ultrasound reacted positively. The results of assays with 38 chemicals and/or radiations in combined treatments, as well as 15 chemicals and three types of radiations that induce somatic mutations are tabulated. The Pisum sativum (2n=14) bioassay has been shown to be a very good plant bioassay for assessing chromosome damage both in mitosis and meiosis for somatic mutations induced by chemicals, radiations, and environmental pollutants. For some chemicals, the Pisum assay is not as sensitive in assessing clastogenicity as the Allium assay, although this should be considered in relative terms. Pisum fulvum (2n=14) has been used in clastogenic studies also, but to a much lesser extent. PMID:11344039

  3. Dynamics of chromosomal aberrations in bone marrow cells of monkeys following prolonged irradiation

    International Nuclear Information System (INIS)

    The effect of prolonged gamma-irradiation with doses of low intensity (3.87 μA/kg) was studied in the bone marrow cells of monkeys (Macaca rhesus). The cumulative dose was 214.14-221.88 mC/kg. Statistically significant differences in the frequency of chromosome aberrations and the percentage of polyploid bone marrow cells, as compared to the level of spontaneous aberrations, were observed during 42 months following the exrosure

  4. Pesticides, Chromosomal Aberrations, and Non-Hodgkin’s Lymphoma

    OpenAIRE

    Chiu, Brian C. -H.; Blair, Aaron

    2009-01-01

    An excessive incidence of non-Hodgkin’s lymphoma (NHL) has been reported among farmers and other occupational groups working with pesticides. Some pesticides exhibit immunotoxic and genotoxic activities. Individuals exposed to pesticides have also been found to have an increased prevalence of chromosomal abnormalities including the t(14;18)(q32;q21), one of the most common chromosomal abnormalities in NHL. Two recent epidemiologic studies reported that the association between pesticide exposu...

  5. Chromosomal aberrations as etiological factors of intrauterine growth retardation

    OpenAIRE

    Petrović Bojana; Ljubić Aleksandar; Nikolić Ljubinka

    2008-01-01

    Background/Aim. Intrauterine growth retardation (IUGR) is a pathological condition of pregnancy characterised by birth weight below the 10th centile. A number of fetal, placental and maternal causes can lead to IUGR; although, in most cases no specific causes can be identified. The aim of this study was to determine the part of chromosomal abnormalities in IUGR etiology. Methods. Fetal blood karyotype taken by cordocentesis from 168 fetuses with diagnosed IUGR was analyzed. Results. Chromosom...

  6. Allium cepa anaphase-telophase root tip chromosome aberration assay on N-methyl-N-nitrosourea, maleic hydrazide, sodium azide, and ethyl methanesulfonate.

    Science.gov (United States)

    Rank, J; Nielsen, M H

    1997-04-24

    The Allium anaphase-telophase assay was used to show genotoxicity of N-methyl-N-nitrosourea (MNU), maleic hydrazide (MH), sodium azide (NaN3) and ethyl methanesulfonate (EMS). All agents induced chromosome aberrations at statistically significant levels. The rank of the lowest doses with positive effect was as follows: NaN3 0.3 mg/l Allium test for NaN3 and EMS were in a lower range than that found for the other plant assays. EMS and MMS (methyl methanesulfonate), two chemicals used as positive controls in mutagenicity testing, were compared in the Allium test, and MMS was found to be about ten times more potent in inducing chromosome aberrations than EMS. Recording of micronuclei in interphase cells showed that this endpoint does not give more information of clastogenicity than recording of chromosome aberrations in anaphase-telophase cells. PMID:9150760

  7. The use of unstable chromosome aberrations and micronuclei in the individual biomonitoring: a comparative study

    International Nuclear Information System (INIS)

    Biodosimetry is based on the investigation of radioinduced biological effects in order to correlate them with the absorbed dose. The quantification of unstable chromosome aberrations and micronuclei, in peripheral blood lymphocytes, are two methods commonly used in biodosimetry. In this context, the aim of this research was to compare these methods in the biomonitoring of health care professionals occupationally exposed to ionizing radiation. In parallel, the technique of C-banding was evaluated for quality control of unstable chromosome aberrations analyses. Thus, samples of peripheral blood from health care professionals of three hospitals from Recife (Brazil) were collected, and the lymphocytes cultures were carried out based on the cytogenetic classical technique. It was pointed out that analysis of micronuclei is faster than the unstable chromosome aberrations ones, which suggests the use of the former in preliminary evaluation in cases of suspected accidental exposure. C-banding technique was efficient, as confirmatory test, in the identification of dicentrics and rings during the analyses of unstable chromosome aberrations, being able to be applied in the quality control in biodosimetry. The comparison between the individual work conditions with the frequencies of unstable aberrations and micronuclei obtained from cytogenetic analysis, resulted in the change of behavior of the professionals involved in this research, with a better observance of the radioprotection standards. (author)

  8. Effects of long-term radiation exposure on chromosomal aberrations in radiological technologists

    International Nuclear Information System (INIS)

    Chromosomal aberrations in the lymphocytes of radiation technologists (RT) were analyzed by the trypsin G-banding method to study the late effects of long-term exposure to low doses of radiation. Structural aberrations were identified in 384 (2.5%) of 15442 cells analyzed from 53 RT as compared to 177 (1.6%) of 11136 cells from 36 healthy controls. Stable aberrations were the most frequent in both groups and were either translocations or deletions. Unstable aberrations were mainly acentric fragments in both groups. The frequency of translocations and acentric fragments was significantly higher in the RT than in the controls and was highest in the RT over 50 years. The highest frequency observed in the >50 age group was attributed to the unknown for cumulative dose prior to introduction of film badges. Frequency of chromosomal aberrations correlated with the estimated dose from the film badges and years of experience of each RT based on the equation y=0.22+0.37D+4.35D2, where y is overall frequency of chromosomal aberrations and D is the estimated radiation dose in Sv. (author)

  9. Chronic γ-irradiation results in increased cell killing and chromosomal aberration with specific breakpoints in fibroblast cell strains derived from non-Hodgkin's lymphoma patients

    International Nuclear Information System (INIS)

    Cultured skin fibroblast cells from 16 NHL (non-Hodgkin's lymphoma) patients and 2 clinically normal subjects were compared for cell survival and chromosomal aberration after chronic γ-irradiation. Fibroblasts from an ataxia telangiectasia (AT) homozygote and an AT heterozygote were used as positive controls. Following irradiation, fibroblasts from all 16 NHL patients showed an increase in both cell death and chromosomal aberration (breaks and rearrangements) compared to normal subjects. The difference in frequency of chromosomal aberration between normals and NHL-patients remained virtually unchanged over a period of 24-72 h post irradiation incubation of cells. Cell cycle analysis by flow cytometry carried out in 1 normal and 1 NHL fibroblast cell strain showed that more cells representing the NHL patient were in G2/M phase compared to the normal at various times of cytogenetic analysis. While the AT homozygote appeared to be the most radiosensitive, the AT heterozygote showed a slightly higher incidence of cell death and chromosomal aberration than the normals. The cellular and chromosomal radiosensitivity of fibroblast cell lines from NHL-patients differed slightly from that of AT heterozygote but clearly occupied an intermediate position between the AT homozygote and the normal subjects. Cells from 3 of the NHL patients showed radiation-induced specific chromosomal breaks involving chromosomes 1, 2, 6, 8, 10 and 11 which correspond to known fragile sites. Such breakpoints associated with increased radiosensitivity may be indicative of predisposition to malignancy in the patients studied. (author). 30 refs., 2 figs., 4 tabs

  10. Deletion of 1p36 as a primary chromosomal aberration in intestinal tumorigenesis

    DEFF Research Database (Denmark)

    Bardi, G; Pandis, N; Fenger, C;

    1993-01-01

    Cytogenetic analysis of short-term cultures from benign intestinal tumors revealed clonal chromosome aberrations in five colorectal adenomas, one adenoma of the papilla Vateri, and one hyperplastic polyp of the rectum. One adenoma had numerical aberrations only, but in all other tumors structural...... hyperplastic polyp. Both adenomas that had additional aberrations beyond the 1p loss showed severe dysplasia. We conclude that cytogenetically detectable loss of genetic information from 1p36 is an early, seemingly primary, premalignant event in intestinal tumorigenesis. The fact that the adenomas with 1p- as...

  11. Induction and persistence of chromosome aberrations in human lymphocytes exposed to neutrons in vitro or in vivo: Implications of findings in 'retrospective' biological dosimetry

    International Nuclear Information System (INIS)

    The induction and persistence were evaluated of chromosome aberrations in lymphocytes exposed in vitro to highly efficient 1 MeV monoenergetic neutrons and in patients who received fast neutrons as therapy for tumours. For the in vitro studies, lymphocytes were exposed to various doses of neutrons and cultured for one or 20 cell cycles. Aberrations were quantified in painted chromosome pairs 1, 2 or 4. These 1 MeV neutrons were highly efficient in inducing aberrations, and dicentrics as well as one-way and two-way translocations increased as a linear function of dose. About 30% of the aberrant metaphases displayed complex aberrations. After multiple in vitro cell divisions, virtually all asymmetrical aberrations had been eliminated from the cell population, and the frequency of one-way translocations was reduced dramatically. In contrast, most two-way translocations apparently survived through multiple cell divisions and still displayed excellent correlation with dose after 20 cell cycles. Classical methods were used to evaluate persistence of aberrations in patients who received fractionated neutron therapy to tumours located in many different sites. Neutron induced dicentrics and rings disappeared from the peripheral circulation within the first three years after exposure, while translocations persisted for more than 17 y. However, considerable variability in numbers of aberrations were observed between patients who had received similar 'average bone marrow doses'. Results of these studies are discussed in relation to the possible use of translocations as retrospective dosemeters in persons exposed to radiation many years ago. (author)

  12. Biodosimetry: chromosome aberration in lymphocytes and electron paramagnetic resonance in tooth enamel from atomic bomb survivors

    International Nuclear Information System (INIS)

    One hundred enamel samples isolated from extracted teeth donated by atomic bomb survivors were subjected to free radical measurement by means of electron paramagnetic resonance (ESR). Results comparing ESR with the chromosome aberration frequency in lymphocytes of the tooth donors, and with the physically estimated DS86 dose suggested that ESR data correlated more closely with chromosome data than with the estimated DS86 doses, probably because DS86 may depend on erroneous memory in some cases. 9 refs, 4 figs

  13. A genome-wide map of aberrantly expressed chromosomal islands in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Castanos-Velez Esmeralda

    2006-09-01

    Full Text Available Abstract Background Cancer development is accompanied by genetic phenomena like deletion and amplification of chromosome parts or alterations of chromatin structure. It is expected that these mechanisms have a strong effect on regional gene expression. Results We investigated genome-wide gene expression in colorectal carcinoma (CRC and normal epithelial tissues from 25 patients using oligonucleotide arrays. This allowed us to identify 81 distinct chromosomal islands with aberrant gene expression. Of these, 38 islands show a gain in expression and 43 a loss of expression. In total, 7.892 genes (25.3% of all human genes are located in aberrantly expressed islands. Many chromosomal regions that are linked to hereditary colorectal cancer show deregulated expression. Also, many known tumor genes localize to chromosomal islands of misregulated expression in CRC. Conclusion An extensive comparison with published CGH data suggests that chromosomal regions known for frequent deletions in colon cancer tend to show reduced expression. In contrast, regions that are often amplified in colorectal tumors exhibit heterogeneous expression patterns: even show a decrease of mRNA expression. Because for several islands of deregulated expression chromosomal aberrations have never been observed, we speculate that additional mechanisms (like abnormal states of regional chromatin also have a substantial impact on the formation of co-expression islands in colorectal carcinoma.

  14. Frequency of chromosomal aberrations in a group of patients carriers of gonosomopathies

    International Nuclear Information System (INIS)

    This paper was aimed at determining the frequency of chromosomal aberrations in a group of patients carriers of gonosomopathies and at relating in each case the meaning of the different chromosomal aberrations found to the patients' clinical diagnosis. 656 patients with presumptive diagnosis of gonosomopathies from different hospital institutions of the country that were received at the molecular genetics laboratory of Hermanos Ameijeiras Clinical and Surgical Hospital from 1982 to 2001, were studied. Of the total of patients with presumptive diagnosis of gonosomopathies, in 32.7 % (215/656) the clinical diagnosis was confirmed by the cytogenetic study. The chromosomal study was conducted by using G band techniques. The chromosomal rearrangements found were classified into 4 groups. The group of numerical gonosomopathies showed the highest frequency with 110 patients, accounting for 51 % of the total. It was followed by the group of numerical and structural alterations (mosaics) with 59 patients (27.0), the inversions of sex with 24 patients (12.0), and the group of structural gonosomopathies with 22 patients (10.0) The most common chromosomal aberrations were the numerical gonosomopathies (Turner and Klinefelter's syndrome). The chromosomal study in these patients is a very important diagnostic value indicator for the therapeutical conduct to be followed in every case

  15. Combining Chromosomal Arm Status and Significantly Aberrant Genomic Locations Reveals New Cancer Subtypes

    Directory of Open Access Journals (Sweden)

    Tal Shay

    2009-01-01

    Full Text Available Many types of tumors exhibit characteristic chromosomal losses or gains, as well as local amplifications and deletions. Within any given tumor type, sample specific amplifications and deletions are also observed. Typically, a region that is aberrant in more tumors, or whose copy number change is stronger, would be considered as a more promising candidate to be biologically relevant to cancer. We sought for an intuitive method to define such aberrations and prioritize them. We define V, the “volume” associated with an aberration, as the product of three factors: (a fraction of patients with the aberration, (b the aberration’s length and (c its amplitude. Our algorithm compares the values of V derived from the real data to a null distribution obtained by permutations, and yields the statistical significance (p-value of the measured value of V. We detected genetic locations that were significantly aberrant, and combine them with chromosomal arm status (gain/loss to create a succinct fingerprint of the tumor genome. This genomic fingerprint is used to visualize the tumors, highlighting events that are co-occurring or mutually exclusive. We apply the method on three different public array CGH datasets of Medulloblastoma and Neuroblastoma, and demonstrate its ability to detect chromosomal regions that were known to be altered in the tested cancer types, as well as to suggest new genomic locations to be tested. We identified a potential new subtype of Medulloblastoma, which is analogous to Neuroblastoma type 1.

  16. Chromosome Aberrations of East Asian Bullfrog (Hoplobatrachus rugulosus around a Gold Mine Area with Arsenic Contamination

    Directory of Open Access Journals (Sweden)

    Atidtaya Suttichaiya

    2016-01-01

    Full Text Available The objectives of this study are to investigate the chromosome aberrations of the East Asian Bullfrog (Hoplobatrachus rugulosus in the gold mine area compared to an unaffected area. Three H. rugulosus were collected, and chromosome aberrations were studied using bone marrow. The level of arsenic was measured in water, sediment and H. rugulosus samples. The average concentrations of arsenic in the water and sediment samples from the gold mine and unaffected areas were 0.03 ± 0.003 mg/l and not detected in water as well as 351.59 ± 5.73 and 1.37 ± 1.07 mg/kg in sediment, respectively. The gold mine values were higher than the permissible limit of the water and soil quality standards, but the arsenic concentrations in the samples from the unaffected area were within prescribed limit. The average concentrations of arsenic in H. rugulosus samples from the gold mine and unaffected areas were 0.39 ± 0.30 and 0.07 ± 0.01 mg/kg, respectively, which were both lower than the standard of arsenic contamination in food. The diploid chromosome number of H. rugulosus in both areas was 2n=26, and the percentage of chromosome breakages of H. rugulosus in the gold mine area were higher than the unaffected area. There were eight types of chromosome aberrations, including a single chromatid gap, isochromatid gap, single chromatid break, isochromatid break, centric fragmentation, deletion, fragmentation and translocation. The most common chromosome aberration in the samples from the affected area was deletion. The difference in the percentage of chromosome breakages in H. rugulosus from both areas was statistically significant (p<0.05.

  17. Nonhomologous DNA end joining and chromosome aberrations in human embryonic lung fibroblasts treated with environmental pollutants

    Czech Academy of Sciences Publication Activity Database

    Rössner ml., Pavel; Rössnerová, Andrea; Beskid, Olena; Tabashidze, Nana; Líbalová, Helena; Uhlířová, Kateřina; Topinka, Jan; Šrám, Radim

    763-764, MAY-JUN 2014 (2014), s. 28-38. ISSN 0027-5107 R&D Projects: GA ČR GAP503/11/0084 Institutional support: RVO:68378041 Keywords : benzo[a]pyrene * chromosome aberrations * double-strand DNA breaks Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 3.680, year: 2014

  18. Effects of LET, fluence and particle energy on inactivation, chromosomal aberrations and DNA strand breaks

    International Nuclear Information System (INIS)

    Experiments are described studying the inactivation and the induction of chromosomal aberrations in mammalian cells. In addition, experiments of the induction of single and double strand breaks of DNA in mammalian cells will be compared to the induction of single and double strand breaks of DNA in solution. (orig./MG)

  19. Aberration distribution and chromosomally marked clones in x-irradiated skin

    International Nuclear Information System (INIS)

    Samples of clinically normal human skin were removed from therapeutically X-irradiated areas at intervals of time ranging from one hour to 60 years after completion of radiation treatment. Primary cultures of untransformed fibroblasts from these samples were analysed for surviving chromosomal structural changes using ASG banding techniques. Aberrations of four basic types, reciprocal translocations, terminal deletions, pericentric inversions and paracentric inversions (the last very rare) were found in all samples. Evidence indicates that many of these are secondary aberrations derived from primary chromatid types. Presumptive break points for all aberrations were mapped, and various tests applied to investigate their within-chromosome distributions (the data are unsuitable for valid between-chromosome analysis). For translocations, the within-arm distributions are non-random, principally as the result of a very significant deficiency of break points in terminal segments. Tests for the intrachromosomal changes (pericentric inversions and deletions) are simpler, and in neither case were there significant departure from randomness Two lines of evidence are present in the data for division and migration of chromosomally abnormal cells in vivo: (a) the presence of identical aberrations in cells from different parts of the biopsy; (b) the presence of cells with sequential changes, indicating cell division between the dose fractions of the therapeutic regime. (author)

  20. A biophysical model applied to survival of tumor cells and chromosomal aberrations in human lymphocytes

    International Nuclear Information System (INIS)

    Investigations on survival of tumor cells E.M.T.6 and chromosomal aberrations in human lymphocytes irradiated in vitro and microdosimetric studies were made using a helion beam. The results obtained were compared in order to see if the Dual Radiation Action Theory of ROSSI and KELLERER can explain these radiobiological phenomena

  1. Chromosomal aberrations in lymphocytes of healthy subjects and risk of cancer

    Czech Academy of Sciences Publication Activity Database

    Rössner st., Pavel; Boffetta, P.; Ceppi, M.; Bonassi, S.; Šmerhovský, Zdeněk; Jůzova, D.; Šrám, Radim

    2005-01-01

    Roč. 113, č. 5 (2005), s. 517-520. ISSN 0091-6765 Institutional research plan: CEZ:AV0Z50390512 Keywords : chromosomal aberrations * cytogenetic assay Subject RIV: EA - Cell Biology Impact factor: 5.342, year: 2005

  2. Association between different types of chromosomal aberrations in human peripheral lymphocytes and cancer in different locations

    Czech Academy of Sciences Publication Activity Database

    Šmerhovský, Zdeněk; Landa, K.; Rössner st., Pavel; Juzova, D.

    2002-01-01

    Roč. 39, č. 33 (2002), s. 59. ISSN 0893-6692. [ Environmental Mutagen Society Annual Meeting /33./. 27.04.2002-02.05.2002, Anchorage - USA] R&D Projects: GA MZd NJ5177 Grant ostatní: GA-(EC) QLK4-2000-00628 Keywords : cytogenic analysis * cancer incidence * chromosomal aberrations Subject RIV: DN - Health Impact of the Environment Quality

  3. Unstable chromosome aberrations on peripheral blood lymphocytes from patients with cervical uterine cancer following radiotherapy

    International Nuclear Information System (INIS)

    Absorbed dose determination is an important step for risk assessment related to an exposure to ionizing radiation. However, physical dosimetry cannot be always performed, principally in the case of retrospective estimates. In this context, the use of bioindicators (biological effects) has been proposed, which defines the so-called biological dosimetry. In particular, scoring of unstable chromosomes aberrations (dicentrics, centric rings and fragments) of peripheral blood lymphocytes, while is the most reliable biological method for estimating individual exposure to ionizing radiation. In this work, blood samples from 5 patients, with cervical uterine cancer, were evaluated after partial-body radiotherapy with a source of 69 Co. For this, conventional cytogenetic method was employed, based on Giemsa coloration and fluorescence in situ hybridization, in order to correlate the frequency of unstable chromosome aberrations of blood lymphocytes with absorbed dose, as a result of the radiotherapy. A good agreement was observed between the frequency of chromosome aberrations scored and the values of dose previously calculated by physical dosimetry during patient's radiotherapy. The results presented in this work point out the importance of concerning analyses of unstable chromosome aberrations as biological dosimeter in the investigation of partial-body exposure to ionizing radiation. (author)

  4. 40 CFR 799.9537 - TSCA in vitro mammalian chromosome aberration test.

    Science.gov (United States)

    2010-07-01

    ... MIXTURE TESTING REQUIREMENTS Health Effects Test Guidelines § 799.9537 TSCA in vitro mammalian chromosome aberration test. (a) Scope—(1) Applicability. This section is intended to meet testing requirements under... somatic cells are involved in cancer induction in humans and experimental animals. (2) The in...

  5. Dynamics of chromosomal aberrations in male mice of various strains during aging.

    Science.gov (United States)

    Rozenfel'd, S V; Togo, E F; Mikheev, V S; Popovich, I G; Zabezhinskii, M A; Anisimov, V N

    2001-05-01

    We studied the incidence of chromosome aberrations in bone marrow cells and primary spermatocytes in various mouse strains. Experiments were performed on SAMP mice (accelerated aging), control SAMR mice, and long-living CBA and SHR mice. Experiments revealed a positive correlation between the age and the incidence of mutations in their somatic cells and gametes. PMID:11550060

  6. Biological dosimetry: registration of stable chromosome aberration by G-banding and FISH methods

    International Nuclear Information System (INIS)

    G-banding analysis and fluorescence in situ hybridization (FISH) for whole chromosomes 1, 2 and 4 were applied in comparative assay for frequency of stable chromosome aberration in 37 individuals with previous exposure to radiation (15 liquidators of Chernobyl Nuclear Power Plant accident and 22 residents of radiocontaminated areas) and in 18 persons of a reference group. Comparison of the results reveals statistical trustworthy correlation between the two assays. The results point out that FISH for translocations in as few as three chromosomes, when combined with screening of numerous metaphases, provides sensitivity comparable with that provided by G-banding which covers the hole genome

  7. Chromosome aberrations and sister chromatid exchanges in Swedish paint industry workers

    Energy Technology Data Exchange (ETDEWEB)

    Haglund, U.; Lundberg, I.; Zech, L.

    1980-12-01

    Workers in the Swedish paint industry exposed to a mixture of organic solvents, mainly containing xylene or toluene, were investigated for genotoxic effects. No difference in the frequency of sister chromatid exchanges (SCE), 0.192 and 0.193 per chromosome, respectively, was noted in the peripheral lymphocytes of the exposed group of 17 workers and their matched reference group. No correlation was found between xylene or toluene exposure and SCE frequency nor between total solvent exposure and SCE frequency. The frequency of chromosome aberrations was also investigated for the five most exposed workers and their matched referents, and no difference was found. There was no correlation between SCE and chromosome breaks.

  8. Cell survival and chromosomal aberrations in CHO-K1 cells irradiated by carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Czub, J. [Institute of Physics, Swietokrzyska Academy, ul. Swietokrzyska 15, 25-406 Kielce (Poland); Banas, D. [Institute of Physics, Swietokrzyska Academy, ul. Swietokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Swietokrzyska 15, 25-406 Kielce (Poland); Blaszczyk, A. [Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Braziewicz, J. [Institute of Physics, Swietokrzyska Academy, ul. Swietokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Swietokrzyska 15, 25-406 Kielce (Poland); Buraczewska, I. [Institute of Nuclear Chemistry and Technology, ul. Dorodna 16, 03-195 Warsaw (Poland); Choinski, J. [Heavy Ion Laboratory, Warsaw University, ul. Pasteura 5A, 02-093 Warsaw (Poland); Gorak, U. [Institute of Experimental Physics, Warsaw University, ul. Hoza 69, 00-681 Warsaw (Poland); Jaskola, M.; Korman, A. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Lankoff, A.; Lisowska, H. [Institute of Biology, Swietokrzyska Academy, ul. Swietokrzyska 15, 25-406 Kielce (Poland); Lukaszek, A. [Institute of Experimental Physics, Warsaw University, ul. Hoza 69, 00-681 Warsaw (Poland); Main School of Fire Service, ul. Slowackiego 52/54, 01-629 Warsaw (Poland); Szeflinski, Z. [Institute of Experimental Physics, Warsaw University, ul. Hoza 69, 00-681 Warsaw (Poland)], E-mail: szef@fuw.edu.pl; Wojcik, A. [Institute of Nuclear Chemistry and Technology, ul. Dorodna 16, 03-195 Warsaw (Poland); Institute of Biology, Swietokrzyska Academy, ul. Swietokrzyska 15, 25-406 Kielce (Poland)

    2009-03-15

    Chinese hamster ovary CHO-K1 cells were exposed to high LET {sup 12}C-beam (LET: 830 keV/{mu}m) in the dose range of 0-6 Gy and to {sup 60}Co irradiation and the RBE value was obtained. Effects of {sup 12}C-beam exposure on cell survival and chromosomal aberrations were calculated. The chromosomal aberration data were fitted with linear equation. The distribution of aberration in cells was examined with a standard u-test and used to evaluate the data according to Poisson probabilities. The variance to the mean ratio {sigma}{sup 2}/Y and the dispersion index (u) were determined. Overdispersion was significant (p<0.05) when the value of u exceeded 1.96.

  9. Chromosome aberration assays in Allium. A report of the U.S. Environmental Protection Agency Gene-Tox Program.

    Science.gov (United States)

    Grant, W F

    1982-11-01

    The common onion (Allium cepa) is an excellent plant for the assay of chromosome aberrations after chemical treatment. Other species of allium (A. cepa var. proliferum, A. carinatum, A. fistulosum and A. sativum) have also been used but to a much lesser extent. Protocols have been given for using root tips from either bulbs or seeds of Allium cepa to study the cytological end-points, such as chromosome breaks and exchanges, which follow the testing of chemicals in somatic cells. It is considered that both mitotic and meiotic end-points should be used to a greater extent in assaying the cytogenetic effects of a chemical. From a literature survey, 148 chemicals are tabulated that have been assayed in 164 Allium tests for the clastogenic effect. Of the 164 assays which have been carried out, 75 are reported as giving a positive reaction (i.e., causing chromosome aberrations), 49 positive and with a dose response, 1 positive and temperature-related, 9 borderline positive, and 30 negative; 76% of the chemicals gave a definite positive response. It is proposed that the Allium test be included among those tests routinely used for assessing chromosomal damage induced by chemicals. PMID:7177154

  10. Early and Late Chromosome Damages in Human Lymphocytes Induced by Gamma Rays and Fe Ions

    Science.gov (United States)

    Sunagawa, Mayumi; Zhang, Ye; Yeshitla, Samrawit; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2014-01-01

    Chromosomal translocations and inversions are considered stable, and cells containing these types of chromosome aberrations can survive multiple cell divisions. An efficient method to detect an inversion is multi-color banding fluorescent in situ hybridization (mBAND) which allows identification of both inter- and intrachromosome aberrations simultaneously. Post irradiation, chromosome aberrations may also arise after multiple cell divisions as a result of genomic instability. To investigate the stable or late-arising chromosome aberrations induced after radiation exposure, we exposed human lymphocytes to gamma rays and Fe ions ex vivo, and cultured the cells for multiple generations. Chromosome aberrations were analyzed in cells collected at first mitosis and at several time intervals during the culture period post irradiation. With gamma irradiation, about half of the damages observed at first mitosis remained after 7 day- and 14 day- culture, suggesting the transmissibility of damages to the surviving progeny. Detailed analysis of chromosome break ends participating in exchanges revealed a greater fraction of break ends involved in intrachromosome aberrations in the 7- and 14-day samples in comparison to the fraction at first mitosis. In particular, simple inversions were found at 7 and 14 days, but not at the first mitosis, suggesting that some of the aberrations might be formed days post irradiation. In contrast, at the doses that produced similar frequencies of gamma-induced chromosome aberrations as observed at first mitosis, a significantly lower yield of aberrations remained at the same population doublings after Fe ion exposure. At these equitoxic doses, more complex type aberrations were observed for Fe ions, indicating that Fe ion-induced initial chromosome damages are more severe and may lead to cell death. Comparison between low and high doses of Fe ion irradiation in the induction of late damages will also be discussed.

  11. Effects of radiation doses on chromosome aberrations and their risk evaluation in monkeys

    International Nuclear Information System (INIS)

    Dose-response relationships were determined using rhesus monkeys and crab-eating monkeys in relation to gamma-ray-induced reciprocal translocations in spermatogonium. As for the formation ability of germ cells, the number of sperms 9 - 10 months after gamma-irradiation returned to the pre-irradiation number. The frequency of spontaneous reciprocal translocations was 0.09 %. The frequency of gamma-ray-induced reciprocal translocations was 1.9 %, 2.5 %, and 1.3 % at doses of 100, 200, and 300 rad, respectively. Individual differences in the expression of reciprocal translocations were 1.4 - 2.1 %, 1.9 - 3.3 %, and 1.4 - 1.6 % at doses of 100, 200, and 300 rad, respectively. There was no significant difference in the frequency between two irradiation experiments. From these results, one to five babies are estimated to have congenital malformations due to radiation-induced chromosome aberrations among 1,000,000 babies born to their parents exposed to one rad of radiation. (Namekawa, K.)

  12. Radioprotective role of imidazole on radiation-induced chromosomal damage in rat bone marrow cells

    International Nuclear Information System (INIS)

    Whole body gamma irradiation (4 Gy) of male laboratory rats, Rattus norvegicus, induced chromosomal damage and decrease of mitotic index in bone marrow cells which were investigated 0-1/2, 6, 24 and 48 hr. After treatment. Chromosomal aberrations observed consisted of chromatid breaks, centromeric attenuation, chromosomal translocations and rings. The intraperitoneal administration of imidazole at 0.35 mg/g body weight prior to irradiation exerted a definite protective character against radiation induced chromosomal aberration and affected the mitotic index of bone marrow cells

  13. Bayesian analysis of overdispersed chromosome aberration data with the negative binomial model

    International Nuclear Information System (INIS)

    The usual assumption of a Poisson model for the number of chromosome aberrations in controlled calibration experiments implies variance equal to the mean. However, it is known that chromosome aberration data from experiments involving high linear energy transfer radiations can be overdispersed, i.e. the variance is greater than the mean. Present methods for dealing with overdispersed chromosome data rely on frequentist statistical techniques. In this paper, the problem of overdispersion is considered from a Bayesian standpoint. The Bayes Factor is used to compare Poisson and negative binomial models for two previously published calibration data sets describing the induction of dicentric chromosome aberrations by high doses of neutrons. Posterior densities for the model parameters, which characterise dose response and overdispersion are calculated and graphed. Calibrative densities are derived for unknown neutron doses from hypothetical radiation accident data to determine the impact of different model assumptions on dose estimates. The main conclusion is that an initial assumption of a negative binomial model is the conservative approach to chromosome dosimetry for high LET radiations. (author)

  14. A comparative analysis of chromosomal aberrations in cultured human lymphocytes due to fluoroquinolone drugs at different expression periods.

    Science.gov (United States)

    Anupama, M; Seiler, J P; Murthy, P B

    2010-05-01

    Fluoroquinolones (FQ) are broad-spectrum antibacterial agents widely used for the treatment of infections with various types of gram negative and gram positive bacteria. Specifically, gatifloxacin (GFX) is under development as a component in a new antituberculosis fixed-dose drug combination. In the context of this project, GFX was also tested for genotoxic activity in human peripheral lymphocytes, and the induction of chromosomal aberrations by GFX in PHA-M stimulated cultured human lymphocytes, investigated under conditions of conventional and increased expression times, was further compared to the analogous effects induced by some other second- and third-generation FQ antibacterial agents, namely ofloxacin (OFX), ciprofloxacin (CFX) and sparfloxacin (SFX). OFX did not induce any significant chromosomal aberrations in human lymphocytes. CFX and SFX exhibited slight to moderate clastogenic potential at cytotoxic concentrations (150, 175, 200 and 225 microg/ml), and GFX, a third-generation FQ, induced a clear, concentration-dependent increase in the frequency of chromosomal aberrations at cytotoxic concentrations (150, 200 and 250 microg/ml). These effects were not apparent when metaphases were analysed at the conventionally used sampling time of 24 h, but only after prolongation of the expression time between treatment and harvesting to a sampling time of 36 h (4 h exposure and 32 h expression period). Also, an increased incidence of numerical aberrations (polyploidy and endoreduplication) was seen with GFX at non-cytotoxic concentrations (12.5, 25, 50 and 75 microg/ml). These effects can be attributed to the slight cross-reactivity of FQs between their inhibitory activity towards their intended targets, the prokaryotic type II topoisomerase enzymes DNA gyrase and topoisomerase IV, and the analogous mammalian enzyme topoisomerase II. We have also observed the formation of polycentrics, i.e., chromosomes with five to six centromeres, a rarely reported structural

  15. Induction of chromosome aberrations in human lymphocytes by technetium-99m. In vitro and in vivo studies

    International Nuclear Information System (INIS)

    In Nuclear Medicine, total body dose calculated after a technetium 99m labeled pharmaceutical administration was very low. Nevertheless, risks evaluation of the radio-induced genetics damages at low doses has become a public health priority. Peripheral lymphocytes can be used to study the effects of ionizing radiations on human cells. The induction by ionizing radiations of unstable structural chromosome aberrations (dicentrics, centrics, and fragments) in peripheral blood lymphocytes is considered to be a useful technique to complete physical dosimetry, and presently is the most advanced biological dosimeter. The aim of the study was to evaluate the potential cytogenetic effects of in vitro and in vivo exposure to technetium 99m (99mTc). Firstly, to evaluate the level of 99mTc activity able to produce a significant number of unstable chromosomal aberrations, specific relationships between activity and number of unstable chromosomal aberrations was established in vitro. The whole blood in vitro irradiation procedure has been performed during 3 hours using microspheres labeled with increasing activities of 99mTc (0, 37, 74, 148, 296, and 444 MBq). Secondly, blood samples from 5 patients scheduled for benign bone disease scintigraphy were collected before and 6 hours after administration of 925 MBq of 99mTc-HDP. Both irradiated whole-blood samples obtained in vitro or in vivo are prepared for conventional scoring by classical Fluorescence Plus Giemsa. For in vivo study, 250 and 500 metaphases were scored respectively before and 6 hours after a bone scan undergone. For in vitro studies, 750 cells were scored per activity. The distribution of unstable chromosome aberrations after in vitro 99mTc irradiation follows a Poisson law. We observed no cytogenetic effect induced by clinical exposure to 99mTc 6 hours after administration versus the control point, as predicted by the in vitro results. Nevertheless, unstable anomalies are lethal to the cell and therefore are

  16. Induction of chromosome aberrations in human lymphocytes by technetium-99m. In vitro and in vivo studies

    Energy Technology Data Exchange (ETDEWEB)

    Jacquet, N.; Petiet, A.; Colas-Linhart, N. [Universit Paris-7 (France). Faculte de Medecine Xavier Bichat; Guiraud-Vitaux, F.; Leroy, A.; Voisin, P.

    2000-05-01

    In Nuclear Medicine, total body dose calculated after a technetium 99m labeled pharmaceutical administration was very low. Nevertheless, risks evaluation of the radio-induced genetics damages at low doses has become a public health priority. Peripheral lymphocytes can be used to study the effects of ionizing radiations on human cells. The induction by ionizing radiations of unstable structural chromosome aberrations (dicentrics, centrics, and fragments) in peripheral blood lymphocytes is considered to be a useful technique to complete physical dosimetry, and presently is the most advanced biological dosimeter. The aim of the study was to evaluate the potential cytogenetic effects of in vitro and in vivo exposure to technetium 99m (99mTc). Firstly, to evaluate the level of 99mTc activity able to produce a significant number of unstable chromosomal aberrations, specific relationships between activity and number of unstable chromosomal aberrations was established in vitro. The whole blood in vitro irradiation procedure has been performed during 3 hours using microspheres labeled with increasing activities of 99mTc (0, 37, 74, 148, 296, and 444 MBq). Secondly, blood samples from 5 patients scheduled for benign bone disease scintigraphy were collected before and 6 hours after administration of 925 MBq of 99mTc-HDP. Both irradiated whole-blood samples obtained in vitro or in vivo are prepared for conventional scoring by classical Fluorescence Plus Giemsa. For in vivo study, 250 and 500 metaphases were scored respectively before and 6 hours after a bone scan undergone. For in vitro studies, 750 cells were scored per activity. The distribution of unstable chromosome aberrations after in vitro 99mTc irradiation follows a Poisson law. We observed no cytogenetic effect induced by clinical exposure to 99mTc 6 hours after administration versus the control point, as predicted by the in vitro results. Nevertheless, unstable anomalies are lethal to the cell and therefore are

  17. The landscape of chromosomal aberrations in breast cancer mouse models reveals driver-specific routes to tumorigenesis

    OpenAIRE

    Ben-David, Uri; Ha, Gavin; Khadka, Prasidda; Jin, Xin; Wong, Bang; Franke, Lude; Golub, Todd R.

    2016-01-01

    Aneuploidy and copy-number alterations (CNAs) are a hallmark of human cancer. Although genetically engineered mouse models (GEMMs) are commonly used to model human cancer, their chromosomal landscapes remain underexplored. Here we use gene expression profiles to infer CNAs in 3,108 samples from 45 mouse models, providing the first comprehensive catalogue of chromosomal aberrations in cancer GEMMs. Mining this resource, we find that most chromosomal aberrations accumulate late during breast tu...

  18. Comparison of effects of six tritiated compounds on chromosomal aberrations in human lymphocytes in vitro and dose-response relationships

    International Nuclear Information System (INIS)

    The effects of six tritiated compounds on chromosomal aberrations were compared in cultured human lymphocytes, and dose-response relationships were analysed. According to the efficiency of inducing aberrations, these compounds could be arranged in decreasing order as follows: 3H-TdR > 3H-UdR > 3H-lysine > 3H-thymine > 3H-leucine > HTO, when the dose-response relationship was expressed in radioactivity/ml of the medium. This order is determined mainly by the radioactivities incorporated into the nuclei or the cells. However, when compared in terms of the dose absorbed by the nuclei or the cells, the differences among various compounds would be much more reduced. The data of aberration yields for different tritium activities (or absorbed dsoes) were fitted satisfactorily to the linear-quadratic dose-response equation Y = A + BX + CX2. The yields of chromatid-type and chromosometype aberrations induced by various tritiated compounds were quite different. These differences are related to the metabolism of the compounds

  19. ETOPOSIDE INDUCES CHROMOSOMAL ABNORMALITIES IN SPERMATOCYTES AND SPERMATOGONIAL STEM CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Marchetti, F; Pearson, F S; Bishop, J B; Wyrobek, A J

    2005-07-15

    Etoposide (ET) is a chemotherapeutic agent widely used in the treatment of leukemia, lymphomas and many solid tumors, such as testicular and ovarian cancers, that affect patients in their reproductive years. The purpose of the study was to use sperm FISH analyses to characterize the long-term effects of ET on male germ cells. We used a mouse model to characterize the induction of chromosomal aberrations (partial duplications and deletions) and whole chromosomal aneuploidies in sperm of mice treated with a clinical dose of ET. Semen samples were collected at 25 and 49 days after dosing to investigate the effects of ET on meiotic pachytene cells and spermatogonial stem-cells, respectively. ET treatment resulted in major increases in the frequencies of sperm carrying chromosomal aberrations in both meiotic pachytene (27- to 578-fold) and spermatogonial stem-cells (8- to 16-fold), but aneuploid sperm were induced only after treatment of meiotic cells (27-fold) with no persistent effects in stem cells. These results demonstrate that male meiotic germ cells are considerably more sensitive to ET than spermatogonial stem-cell and that increased frequencies of sperm with structural aberrations persist after spermatogonial stem-cell treatment. These findings predict that patients who undergo chemotherapy with ET may have transient elevations in the frequencies of aneuploid sperm, but more importantly, may have persistent elevations in the frequencies of sperm with chromosomal aberrations, placing them at higher risk for abnormal reproductive outcomes long after the end of their chemotherapy.

  20. Doses in radiation accidents investigated by chromosome aberration analysis

    International Nuclear Information System (INIS)

    The results are reviewed from investigations during 1980 into 68 cases of suspected overexposure to radiation. Of these, 37 were associated with industrial radiography, 11 with one or other of the major nuclear organisations and 20 with an institution of research, education or health. 55 of the dose estimates were in the range 0.0 - 0.09 Gy (0 - 9 rad) 5 in the range 0.1 - 0.29 Gy (10 - 29 rad) and for various reasons in 8 cases no biological assessment of dose was possible. The dose estimate for the case with the highest confirmed overexposure was 0.22 Gy (22 rads). The chromosome data are compared with information obtained from physical dosimetry and a brief summary is given of the circumstances of each case. (author)

  1. Use of FISH-translocations analyses for retrospective biological dosimetry: How stable are stable chromosome aberrations?

    International Nuclear Information System (INIS)

    Chromosome aberrations, in particular dicentrics, in peripheral blood lymphocytes are used to estimate the absorbed dose immediately following a radiation accident. However, difficulties for dose estimation arise with old exposures, due to a decline of cells containing unstable dicentric aberrations. The fluorescence in situ hybridisation (FISH) technique employing chromosome specific DNA libraries to 'paint' individual human chromosomes has opened new perspectives for rapid and reliable detection of stable chromosome aberrations such as translocations. The inherent stability of translocations over cell generations has enabled them to be used as a biodosemeter. However, due to the limited life of circulating T-lymphocytes, a level of uncertainty exists on the long-term persistence of stable translocations. The objectives of the present work are to present the current state of knowledge on the stability of translocations detected by FISH. The following aspects have been considered; (1) experience so far of retrospective biological dosimetry in humans following accidental and occupational over-exposure, (2) animal studies using mice and monkeys, (3) the influence of subsequent cell divisions on the yield and persistence of translocations following in vitro irradiation of human lymphocytes, and (4) the needs for further work to standardise and validate the use of FISH as a biological dosemeter, and to investigate the influence of various parameters such as radiation quality, dose rate and the discrimination of sub-types of translocations on persistence. (author)

  2. Chromosome aberrations in human lymphocytes, chronically exposed to different doses of gamma radiation in vitro

    International Nuclear Information System (INIS)

    Man's blood, not stimulated with phytohemagglutinin has been subjected to a chronic gamma irradiation from the 226Ra(99 mg) source at the temperature of 37 deg C. The obtained metaphase plates have been used to carry out the quantitative analysis of separate types of structural chromosomal aberrations. Quantitative results on aberrant cells have been statistically processed. It is established, that the increase of dose rate lends to the increase in the share of those dicentrics, that appeared as a result of one-trail process, while that output of two-trail dicentrics remains constant

  3. Alternative Lengthening of Telomeres: Recurrent Cytogenetic Aberrations and Chromosome Stability under Extreme Telomere Dysfunction

    Directory of Open Access Journals (Sweden)

    Despoina Sakellariou

    2013-11-01

    Full Text Available Human tumors using the alternative lengthening of telomeres (ALT exert high rates of telomere dysfunction. Numerical chromosomal aberrations are very frequent, and structural rearrangements are widely scattered among the genome. This challenging context allows the study of telomere dysfunction-driven chromosomal instability in neoplasia (CIN in a massive scale. We used molecular cytogenetics to achieve detailed karyotyping in 10 human ALT neoplastic cell lines.We identified 518 clonal recombinant chromosomes affected by 649 structural rearrangements. While all human chromosomes were involved in random or clonal, terminal, or pericentromeric rearrangements and were capable to undergo telomere healing at broken ends, a differential recombinatorial propensity of specific genomic regions was noted.We show that ALT cells undergo epigenetic modifications rendering polycentric chromosomes functionally monocentric, and because of increased terminal recombinogenicity, they generate clonal recombinant chromosomes with interstitial telomeric repeats. Losses of chromosomes 13, X, and 22, gains of 2, 3, 5, and 20, and translocation/deletion events involving several common chromosomal fragile sites (CFSs were recurrent. Long-term reconstitution of telomerase activity in ALT cells reduced significantly the rates of random ongoing telomeric and pericentromeric CIN. However, the contribution of CFS in overall CIN remained unaffected, suggesting that in ALT cells whole-genome replication stress is not suppressed by telomerase activation. Our results provide novel insights into ALT-driven CIN, unveiling in parallel specific genomic sites that may harbor genes critical for ALT cancerous cell growth.

  4. Somatic pairing, endomitosis and chromosome aberrations in snakes (Viperidae and Colubridae

    Directory of Open Access Journals (Sweden)

    Beçak Maria Luiza

    2003-01-01

    Full Text Available The positioning of macrochromosomes of Bothrops jararaca and Bothrops insularis (Viperidae was studied in undistorted radial metaphases of uncultured cells (spermatogonia and oogonia not subjected to spindle inhibitors. Colchicinized metaphases from uncultured (spleen and intestine and cultured tissues (blood were also analyzed. We report two antagonic non-random chromosome arrangements in untreated premeiotic cells: the parallel configuration with homologue chromosomes associated side by side in the metaphase plate and the antiparallel configuration having homologue chromosomes with antipolar distribution in the metaphase ring. The antiparallel aspect also appeared in colchicinized cells. The spatial chromosome arrangement in both configurations is groupal size-dependent and maintained through meiosis. We also describe, in untreated gonia cells, endomitosis followed by reductional mitosis which restores the diploid number. In B. jararaca males we observed that some gonad regions present changes in the meiotic mechanism. In this case, endoreduplicated cells segregate the diplochromosomes to opposite poles forming directly endoreduplicated second metaphases of meiosis with the suppression of first meiosis. By a successive division, these cells form nuclei with one set of chromosomes. Chromosome doubling in oogonia is known in hybrid species and in parthenogenetic salamanders and lizards. This species also presented chromosome rearrangements leading to aneuploidies in mitosis and meiosis. It is suggested that somatic pairing, endomitosis, meiotic alterations, and chromosomal aberrations can be correlated processes. Similar aspects of nuclei configurations, endomitosis and reductional mitosis were found in other Viperidae and Colubridae species.

  5. Alternative lengthening of telomeres: recurrent cytogenetic aberrations and chromosome stability under extreme telomere dysfunction.

    Science.gov (United States)

    Sakellariou, Despoina; Chiourea, Maria; Raftopoulou, Christina; Gagos, Sarantis

    2013-11-01

    Human tumors using the alternative lengthening of telomeres (ALT) exert high rates of telomere dysfunction. Numerical chromosomal aberrations are very frequent, and structural rearrangements are widely scattered among the genome. This challenging context allows the study of telomere dysfunction-driven chromosomal instability in neoplasia (CIN) in a massive scale. We used molecular cytogenetics to achieve detailed karyotyping in 10 human ALT neoplastic cell lines. We identified 518 clonal recombinant chromosomes affected by 649 structural rearrangements. While all human chromosomes were involved in random or clonal, terminal, or pericentromeric rearrangements and were capable to undergo telomere healing at broken ends, a differential recombinatorial propensity of specific genomic regions was noted. We show that ALT cells undergo epigenetic modifications rendering polycentric chromosomes functionally monocentric, and because of increased terminal recombinogenicity, they generate clonal recombinant chromosomes with interstitial telomeric repeats. Losses of chromosomes 13, X, and 22, gains of 2, 3, 5, and 20, and translocation/deletion events involving several common chromosomal fragile sites (CFSs) were recurrent. Long-term reconstitution of telomerase activity in ALT cells reduced significantly the rates of random ongoing telomeric and pericentromeric CIN. However, the contribution of CFS in overall CIN remained unaffected, suggesting that in ALT cells whole-genome replication stress is not suppressed by telomerase activation. Our results provide novel insights into ALT-driven CIN, unveiling in parallel specific genomic sites that may harbor genes critical for ALT cancerous cell growth. PMID:24339742

  6. Chromosomal aberrations suggestive of mutagen-related leukemia after 21 years of therapeutic radon exposure

    International Nuclear Information System (INIS)

    A 68-year-old woman with acute myelomonocytic leukemia, who was treated annually for 21 consecutive years by therapeutic low-dose radon gas radiation because of spondyloarthritis, is described. The karyotype of the malignant clone was 45,XX, -17, -18,del(5)(q15q33), +t(17;18)(q11.2q23). In 45% of the metaphases, the modal number was between hyperdiploid to near tetraploid. Double minute chromosomes were demonstrated in 60% of the cells. These chromosomal aberrations are suggestive of mutagen-related leukemia

  7. Cell-autonomous correction of ring chromosomes in human induced pluripotent stem cells

    Science.gov (United States)

    Bershteyn, Marina; Hayashi, Yohei; Desachy, Guillaume; Hsiao, Edward C.; Sami, Salma; Tsang, Kathryn M.; Weiss, Lauren A.; Kriegstein, Arnold R.; Yamanaka, Shinya; Wynshaw-Boris, Anthony

    2014-03-01

    Ring chromosomes are structural aberrations commonly associated with birth defects, mental disabilities and growth retardation. Rings form after fusion of the long and short arms of a chromosome, and are sometimes associated with large terminal deletions. Owing to the severity of these large aberrations that can affect multiple contiguous genes, no possible therapeutic strategies for ring chromosome disorders have been proposed. During cell division, ring chromosomes can exhibit unstable behaviour leading to continuous production of aneuploid progeny with low viability and high cellular death rate. The overall consequences of this chromosomal instability have been largely unexplored in experimental model systems. Here we generated human induced pluripotent stem cells (iPSCs) from patient fibroblasts containing ring chromosomes with large deletions and found that reprogrammed cells lost the abnormal chromosome and duplicated the wild-type homologue through the compensatory uniparental disomy (UPD) mechanism. The karyotypically normal iPSCs with isodisomy for the corrected chromosome outgrew co-existing aneuploid populations, enabling rapid and efficient isolation of patient-derived iPSCs devoid of the original chromosomal aberration. Our results suggest a fundamentally different function for cellular reprogramming as a means of `chromosome therapy' to reverse combined loss-of-function across many genes in cells with large-scale aberrations involving ring structures. In addition, our work provides an experimentally tractable human cellular system for studying mechanisms of chromosomal number control, which is of critical relevance to human development and disease.

  8. An influence of occupational exposure on level of chromosome aberrations in nuclear power plant workers

    International Nuclear Information System (INIS)

    Complete text of publication follows. Objective. The workers of Ignalina Nuclear Power Plant (INPP) receive the highest occupational ionising radiation doses in Lithuania. Their occupational exposure results mainly from external low LET gamma radiation. Some workers receive additional internal and neutron exposure. Though exposure doses are generally low and don't exceed the annual dose limit, the higher doses are obtained during outages. The aim of the present study was to analyse chromosome aberration frequencies in lymphocytes of INPP workers exposed to the different types of ionising radiation. Methods. The blood sampling of 52 INPP male workers was performed in 2004-2006. For 29 workers radiation exposure resulted from the external gamma rays only. Their mean annual dose averaged over the 3-year period prior blood sampling was 11.7±8.7 mSv. The mean cumulative dose - 197.7±174.7 mSv. 15 workers had an intake of gamma radionuclides (60Co, 137Cs), contributing to the doses less than 0.1 mSv. Their mean cumulative dose - 278.2±191.9 mSv. The mean annual dose averaged over the 3-year period prior blood sampling was 11.8±5.3 mSv. For 8 subjects neutron doses below 0.2 mSv were recorded. Their mean annual dose averaged over the 3-year period prior blood sampling was 7.0±2.9 mSv. The mean cumulative dose was 241.8±93.0 mSv. Heparinized venous blood samples were taken and cultures were initiated according to the standard procedures. Phytohaemagglutinin (7.8 μg/ml) stimulated cultures were incubated at 37degC for 72 hours in RPMI 1640 medium supplemented with 12% heat-inactivated newborn calf serum, 40 μg/ml gentamycin. Colchicine was added to the culture during the initiation at a final concentration of 0,25 μg/ml. The harvested lymphocytes were treated with hypotonic KCl (0,075 M) and then fixed in methanol-glacial acetic acid (3:1). Flame-dried slides were stained with Giemsa, coded and scored blind. Generally 500 first-division cells per individual were

  9. Impact of types of lymphocyte chromosomal aberrations on human cancer risk

    DEFF Research Database (Denmark)

    Hagmar, Lars; Strömberg, Ulf; Bonassi, Stefano; Hansteen, Inger-Lise; Knudsen, Lisbeth E.; Lindholm, Carita; Norppa, Hannu

    2004-01-01

    The frequency of cells with structural chromosomal aberrations (CAs) in peripheral blood lymphocytes is the first genotoxicity biomarker that has shown an association with cancer risk. CAs are usually divided into chromosome-type (CSAs) and chromatid-type aberrations (CTAs), with different...... mechanisms of formation. From a mechanistic point of view, it is of interest to clarify whether the cancer predictivity of CAs is different with respect to CSAs and CTAs. We report here cancer risk for cytogenetically tested, healthy subjects with respect to frequency of CAs, CSAs, and CTAs in peripheral...... the Nordic cohorts and increased total cancer mortality in the Italian cohort. In the Nordic cohorts, significantly elevated cancer risks were observed for subjects with both high CSAs and high CTAs at test, and these variables showed equally strong cancer predictivity. The results of the Italian...

  10. Anti-genotoxic effect of the Sargassum dentifolium extracts: prevention of chromosomal aberrations, micronuclei, and DNA fragmentation.

    Science.gov (United States)

    Gamal-Eldeen, Amira M; Abo-Zeid, Mona A M; Ahmed, Eman F

    2013-01-01

    The alga Sargassum dentifolium (Turner) C. Agardh, belongs to Sargassaceae, is a brown seaweed in red sea shores in Egypt. This work aimed to extract different water-soluble polysaccharide extracts (E1, E2, and E3) from S. dentifolium and to investigate their protective effect against cyclophosphamide (CP)-induced genotoxicity. Mice bone marrow cells (BMCs) were collected and analyzed for the chromosomal aberration, micronucleated BMCs (MN-BMCs), the mitotic index, DNA fragmentation by comet assay, and histone deacetylases (HDACs), and radical scavenging capacity of extracts was evaluated by the oxygen radical absorbance capacity assay. The results indicated that E2 and E3 significantly inhibited CP-induced multiple chromosomal aberrations, where E1 and E3 significantly suppressed the number of CP-induced formation of tetraploidy. The extracts prohibited the cytotoxic effect of CP and recovered the mitotic activity, whereas E1 possessed the highest recovery and mitosis. In absence of MN, CP induced formation of bi- and poly-nucleated BMCs. E1 prohibited CP-induced formation of bi-nucleated BMCs, while E2 and E3 prohibited CP-induced formation of poly-nucleated BMCs. CP-induced MN-BMCs were accompanied with mono-, bi- and poly-nucleated cells. E1 and E3 remarkably suppressed mono-nucleated MN-BMCs, while E2 inhibited bi-nucleated MN-BMCs. All the extracts significantly inhibited the CP-induced formation of poly-nucleated MN-BMCs. CP-induced DNA fragmentation was inhibited by all extracts, where E1 was the strongest inhibitor as concluded from the comet tail moment. All the extracts were strong OH scavengers, while only E3 was ROO scavenger. The results revealed a drastic decline in HDACs activity by E1 and E3. In conclusion, S. dentifolium polysaccharide extracts E1 and E3 possessed a potential anti-genotoxic and a promising anti-mutagenic activity. PMID:21652192

  11. Frequency of sister chromatid exchange and chromosomal aberrations in asbestos cement workers.

    OpenAIRE

    Fatma, N; Jain, A. K.; Rahman, Q

    1991-01-01

    Exposure to asbestos minerals has been associated with a wide variety of adverse health effects including lung cancer, pleural mesothelioma, and cancer of other organs. It was shown previously that asbestos samples collected from a local asbestos factory enhanced sister chromatid exchanges (SCEs) and chromosomal aberrations in vitro using human lymphocytes. In the present study, 22 workers from the same factory and 12 controls were further investigated. Controls were matched for age, sex, and...

  12. Lymphocyte chromosome aberrations in patients undergoing radiation therapy for mammary carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, A.; Fabry, L.; Lemaire, M. (Centre d' Etude de l' Energie Nucleaire, Mol (Belgium)); Gerber, G.B. (Liege Univ. (Belgium))

    1983-01-01

    Patients undergoing radiation therapy for mammary carcinoma have been cytologically examined for the presence of polycentric chromosomes in their peripheral blood lymphocytes. The mean values of the observed yields can be fitted to a quadratic function. Due probably to a lower number of lymphocytes exposed the curve now obtained gives a smaller aberration yield than the dose effect curves published earlier for patients given telecobalt therapy.

  13. Lymphocyte chromosome aberrations in patients undergoing radiation therapy for mammary carcinoma

    International Nuclear Information System (INIS)

    Patients undergoing radiation therapy for mammary carcinoma have been cytologically examined for the presence of polycentric chromosomes in their peripheral blood lymphocytes. The mean values of the observed yields can be fitted to a quadratic function. Due probably to a lower number of lymphocytes exposed the curve now obtained gives a smaller aberration yield than the dose effect curves published earlier for patients given telecobalt therapy. (Auth.)

  14. Study on the cytotoxicity and chromosome aberration following implantation of sea coral in rabbits

    OpenAIRE

    Kannan TP; Freeda Woon Faiza Woon Tai Keat; Widowati Witjaksono; Abdul Rani Samsudin

    2006-01-01

    Coral has been used as a bone substitute in many experimental studies. It has been proven to be biocompatible, biodegradable and easy to handle: and it has not been found to cause any inflammatory responses. The present study was undertaken to determine the cytotoxicity in terms of mitotic index as well as the clastogenic effect (chromosome aberration) of sea coral implantation in rabbits. The animals comprised of five male adult healthy New Zealand White (Oryctolagus cuniculus) rabbits. The ...

  15. Chromosomal aberrations by fluorescence in situ hybridization (FISH) – biomarker of exposure to carcinogenic PAHs

    Czech Academy of Sciences Publication Activity Database

    Beskid, Olena; Binková, Blanka; Dušek, Zdík; Rössner st., Pavel; Solanský, I.; Kalina, I.; Židzik, J.; Popov, T. A.; Farmer, P. B.; Šrám, Radim

    2007-01-01

    Roč. 620, - (2007), s. 62-70. ISSN 0027-5107 R&D Projects: GA MŽP SL/740/5/03 Grant ostatní: EU(NO) 2000-00091 Institutional research plan: CEZ:AV0Z50390512 Source of funding: R - rámcový projekt EK Keywords : chromosomal aberrations * polycyclic aromatic hydrocarbons * occupational exposure Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 4.159, year: 2007

  16. RBE of d(50)-Be neutrons for induction of chromosome aberrations in Allium cepa onion roots

    International Nuclear Information System (INIS)

    RBE/absorbed dose relationship of d(50)-Be neutrons was determined for the induction of chromosome aberrations in Allium cepa onion roots. Neutrons are produced at the cyclotron 'Cyclone' by bombarding a thick beryllium target with 50 MeV deuterons. Two biological criteria were selected: (1) mean number of aberrations (mainly breaks) per cell in anaphase and telophase, (2) fraction of intact cells in anaphase and telophase. For the two criteria, RBE increases continuously from about 7 to 12 as the neutron absorbed dose decreases from 0.4 to 0.1 Gy. RBE values for the first criterion are slightly higher than for the second one. This observation is interpreted in terms of the analysis of the distribution of the aberrations in the cells. In logarithmic coordinates, RBE/absorbed dose relationships for the two criteria are almost linear with a slope close to - 1/2. RBE values observed for induction of chromosome aberrations in Allium cepa are higher than those generally observed for biological effects related to mammalian cell lethality. (orig.)

  17. Chromosome aberrations in somatic and germ cells following exposure to 300 R X-ray to rabbits

    International Nuclear Information System (INIS)

    A comparison is made of the chromosome aberrations yield in peripheral blood lymphocytes and spermatogonia of rabbits following exposure to 300 R X-rays. Cytogenetic analysis of lymphocytes immediately after irradiation revealed 28,0 per cent aberrant cells, including 0,17 dicentrics per cell. 120 days later less aberrations in primary spermatocytes at diakinesis - metaphasis I - 0,025 translocations per cell - were found. 60 days after irradiation the aberration rate in lymphocytes drops to the spontaneous level - 0,16 per cent aberrant cells - but analysis of karyotyped metaphases show anomalies which are unidentifiable after simple microscopic scoring. (A.B.)

  18. New type of chromosomal aberrations in microspores of Tradescancia Paludosa in flight experiments on board of space satelites

    International Nuclear Information System (INIS)

    A new type of chromosomal aberrations - complex nonreciprocal translocations accompanied by spherical fragments, is opened. The results of 30 variants of tests are investigated to establish what factor particularly causes new type of chromosomal aberrations. The experiments have been carried out on boards the space satelites: ''Vostok 3, 4, 5, 6'', ''Voskhod'', ''Kosmos 110'', ''Zond 6, 7'', ''Kosmos 368''. All type of aberrations have been recorded. It is supposed that a new type of aberrations depends on the effect of the sum of dynamic factors. At the same time these aberrations are not the background and escape it by separate bright bursts being independent on the effect of take-off, landing and time of an object staying in weightlessness. There is a type of irradiation causing a special type of aberrations

  19. Six years of cytogenetic follow-up of unstable chromosome aberrations in Goiania patients

    International Nuclear Information System (INIS)

    Following the radiological accident which occurred in the city of Goiania (Brazil), in September of 1987, a cytogenetic follow-up of 16 exposed patients was started, aiming to observe the mean life time of lymphocytes containing dicentric and ring aberrations. The results suggest that for the highly exposed individuals (doses above 1 Gy) the disappearance rate of unstable aberrations follows a two-term exponential function. Up to 470 days after exposure, there is a rapid fall in the aberration frequency. After 470 days, the disappearance rate is very slow. These results may reflect different subpopulations of human lymphocytes, with different life spans. The estimated average half-time of elimination of dicentrics and rings among the highly exposed group (doses above 1 Gy) was 140 days for the initial period after the exposure (up to 470 days). This value is significantly shorter than the usually accepted value of 3 years reported in the literature. For the individuals who had received less than 1 Gy the disappearance of aberrations seems to have occurred in a slower way. Mean disappearance functions of unstable chromosome aberrations were inferred, to be applied in accident situations in which there is a blood sampling delay. (author)

  20. Computer aided analysis of additional chromosome aberrations in Philadelphia chromosome positive acute lymphoblastic leukaemia using a simplified computer readable cytogenetic notation

    Directory of Open Access Journals (Sweden)

    Mohr Brigitte

    2003-01-01

    Full Text Available Abstract Background The analysis of complex cytogenetic databases of distinct leukaemia entities may help to detect rare recurring chromosome aberrations, minimal common regions of gains and losses, and also hot spots of genomic rearrangements. The patterns of the karyotype alterations may provide insights into the genetic pathways of disease progression. Results We developed a simplified computer readable cytogenetic notation (SCCN by which chromosome findings are normalised at a resolution of 400 bands. Lost or gained chromosomes or chromosome segments are specified in detail, and ranges of chromosome breakpoint assignments are recorded. Software modules were written to summarise the recorded chromosome changes with regard to the respective chromosome involvement. To assess the degree of karyotype alterations the ploidy levels and numbers of numerical and structural changes were recorded separately, and summarised in a complex karyotype aberration score (CKAS. The SCCN and CKAS were used to analyse the extend and the spectrum of additional chromosome aberrations in 94 patients with Philadelphia chromosome positive (Ph-positive acute lymphoblastic leukemia (ALL and secondary chromosome anomalies. Dosage changes of chromosomal material represented 92.1% of all additional events. Recurring regions of chromosome losses were identified. Structural rearrangements affecting (pericentromeric chromosome regions were recorded in 24.6% of the cases. Conclusions SCCN and CKAS provide unifying elements between karyotypes and computer processable data formats. They proved to be useful in the investigation of additional chromosome aberrations in Ph-positive ALL, and may represent a step towards full automation of the analysis of large and complex karyotype databases.

  1. Micronuclei and Chromosome Aberrations Found 1n Bone Marrow Cells and Lymphocytes from Thorotrast Patients and Atomic Bomb Survivors

    OpenAIRE

    Tanaka, Kimio; Izumi, Takaki; Ohkita, Takeshi; Kamada, Nanao

    1984-01-01

    As two cytogenetic parameters of radiation exposure, the frequency of micronucleus in erythroblasts, lymphocytes and red cells (Howell-Jolly body) as well as chromosome aberrations in bone marrow cells and in lymphocytes were studied in 24 thorotrast patients and in 32 atomic bomb (A-bomb) survivors who were exposed within one kilometer from the Hiroshima hypocenter. The incidence of both micronucleus and chromosome aberrations in these two exposed groups were significantly higher than that i...

  2. Chromosome aberration frequency in blood lymphocytes of animals with 239Pu lung burdens

    International Nuclear Information System (INIS)

    Other investigators have suggested a causal relationship between accidental 239Pu exposures in man and the presence of chromosome aberrations in blood lymphocytes. To assess this relationship experimimentally, 16 Rhesus monkeys and 171 Chinese hamsters were exposed by inhalation to 239PuO2 aerosols and an additional five hamsters were injected with 239Pu citrate and the frequency of aberrations in blood lymphocytes determined. After an initial rapid clearance phase, the 239Pu was retained in the monkey lung with a long effective half-life (greater than 500 days). At 30 days after inhalation, 99 percent of the sacrifice body burden was in the lungs of both species. The ranges of cumulative radiation dose to the hamster lungs 30 days after inhalation were calculated to be 80 to 170, 220 to 540, and 830 to 2120 rads for initial lung burden levels of 10 to 30, 30 to 70, and 180 to 260 nCi/g, respectively. By 120 days, these doses were calculated to be 40 to 350, 500 to 710, and 1440 to 2170 rads. Hamsters with the highest lung burdens had a median survival time of about 80 days. No deaths occurred in any of the other treated hamsters or monkeys by 250 days after 239Pu inhalation. Hamsters sacrificed at 30 days showed an increase in chromosome aberration frequency with increasing dose to lung. By 120 days after inhalation, the aberration frequency in the controls was 0.012. The frequency in animals with doses that produced significant life shortening (1440 to 2170 rads) had decreased to 0.018 and to 0.032 aberrations/cell in animals with lung doses of 500 to 710 rads. At 380 days after injection of 60 nCi 239Pu citrate/gm, hamster lymphocytes had an aberration frequency of 0.048 aberrations/cell. The level of chromosome damage in the 239PuO2 exposed monkeys at 30 and 90 days after inhalation was not different than observed in controls. (U.S.)

  3. Chromosome aberrations and rogue cells in lymphocytes of Chernobyl clean-up workers

    International Nuclear Information System (INIS)

    A cytogenetic analysis was performed on peripheral blood lymphocytes from 183 Chernobyl clean-up workers and 27 control individuals. Increased frequencies of chromosome aberrations were associated with exposure to radiation at Chernobyl, alcohol abuse and a history of recent influenza infection. However, only approximately 20% of Chernobyl clean-up workers had an increased frequency of dicentric and ring chromosomes. At the same time, an increased frequency of acentric fragments in lymphocytes of clean-up workers was characteristic. The use of multivitamins as dietary supplement significantly decreased the frequency of chromosome aberrations, especially of chromatid breaks. Rogue cells were found in lymphocytes of 28 clean-up workers and 3 control individuals. The appearance of rogue cells was associated with a recent history of acute respiratory disease (presumably caused by adenoviral infection) and, probably, alcohol abuse. Dicentric chromosomes in rogue cells were distributed according to a negative binomial distribution. Occurrence of rogue cells due to a perturbation of cell cycle control and abnormal apoptosis is suggested

  4. Dose-dependence of the chromosome aberration yield in a human lymphocyte culture after. gamma. -irradiation with high doses

    Energy Technology Data Exchange (ETDEWEB)

    Sevan' kaev, A.V. (Akademiya Meditsinskikh Nauk SSSR, Obninsk. Nauchno-Issledovatel' skij Inst. Meditsinskoj Radiologii)

    A study was made of the yield of chromosome aberrations in a human lymphocyte culture at the G/sub 0/ stage after /sup 60/Co-..gamma..-irradiation with doses of 5-12 Gy. It was shown that a linear-quadratic dependence of the aberration frequency observed with median doses became purely linear at high doses.

  5. X-radiation-induced chromosome breakage in retinoblastoma lymphocytes

    International Nuclear Information System (INIS)

    The authors have examined the spontaneous and X-radiation-induced chromosomal damage in normal humans and in patients with retinoblastoma using the BudR-Giemsa technique in lymphocytes cultured for 48 h. 9 sporadic unilateral non-hereditary cases, 11 hereditary cases and 20 healthy individuals were studied simultaneously. No difference in the spontaneous frequency of chromatid and chromosome aberrations was observed between patients and controls. The results suggest that: (a) There is no relationship between spontaneous chromosome fragility and retinoblastoma. (b) Sporadic unilateral non-hereditary retinoblastoma has normal chromosome sensitivity to X-irradiation. (c) Some hereditary cases of retinoblastoma are sensitive to X-rays while others behave like normals. A mutation or a submicroscopic deletion at a DNA repair locus which is independent of the retinoblastoma gene may cause this radiosensitivity. (Auth.)

  6. Chromosome aberration analysis in peripheral lymphocytes of Gulf war and Balkans war veterans

    International Nuclear Information System (INIS)

    Chromosome aberrations and sister chromatid exchanges (SCEs) were determined in standard peripheral lymphocyte metaphase preparations of 13 British Gulf War veterans, two veterans of the recent war in the Balkans, and one veteran of both wars. All 16 volunteers suspect exposures to depleted uranium while deployed at the two different theatres of war in 1990 and later on. The Bremen laboratory control served as a reference in this study. Compared with this control there was a statistically significant increase in the frequency of dicentric chromosomes (dic) and centric ring chromosomes (cR) in the veterans' group, indicating a previous exposure to ionising radiation. The statistically significant overdispersion of dic and cR indicates non-uniform irradiation as would be expected after non-uniform exposure and/or exposure to radiation with a high linear energy transfer. The frequency of SCEs was decreased when compared with the laboratory control. (author)

  7. Influence of caffeine on chromosome lesions induced by chemical mutagens and radiation. 2

    International Nuclear Information System (INIS)

    The modifying influence of caffeine on γ-ray induced chromosome lesions was studied by chromosome aberration anaysis. Caffeine was applied as a pre- and post-treatment agent following seed (G1) and root meristem (G2 and S) irradiation of C.capillaris. The frequency of chromosome aberrations induced in G1 was changed neither by post- nor by pre-treatment with caffeine. This fact proves the lack of caffeine modifying effect. Applied as a post-treatment agent caffeine enhances considerably the frequency of chromosome aberrations induced in root meristem cells. This is especially valid for G2 irradiated cells, while in S cells no synergistic effect was established between induced chromosome lesions and caffeine. The enhancement of chromosome aberration frequency produced in G2 shows a clearly manifested dependence on the time (moment) of caffeine application post irradiation. Most considerable enhancement was obtained following post-treatment with caffeine immediately after irradiation. In the following intervals - 15 and 30 min - it decreases progressively, while after 60, 180 and 300 min no enhancing effect is observed. The probable causes for the manifestation and the lack of synergistic effect between chromosome lesions induced in the various mitotic cycle phases and caffeine are discussed. (author)

  8. Chromatic variation of aberration: the role of induced aberrations and raytrace direction

    Science.gov (United States)

    Berner, A.; Nobis, T.; Shafer, D.; Gross, H.

    2015-09-01

    The design and optimization process of an optical system contains several first order steps. The definition of the appropriate lens type and the fixation of the raytrace direction are some of them. The latter can be understood as a hidden assumption rather than an aware design step. This is usually followed by the determination of the paraxial lens layout calculated for the primary wavelength. It is obvious, that for this primary wavelength the paraxial calculations are independent of raytrace direction. Today, most of the lens designs are specified not to work only for one wavelength, but in a certain wavelength range. Considering such rays of other wavelengths, one can observe that depending on the direction there will already occur differences in the first order chromatic aberrations and additionally in the chromatic variation of the third-order aberrations. The reason for this effect are induced aberrations emerging from one surface to the following surfaces by perturbed ray heights and ray angles. It can be shown, that the total amount of surface-resolved first order chromatic aberrations and the chromatic variation of the five primary aberrations can be split into an intrinsic part and an induced part. The intrinsic part is independent of the raytrace direction whereas the induced part is not.

  9. Caffeine potentiates or protects against radiation-induced DNA and chromosomal damage in human lymphocytes depending on temperature and concentration

    International Nuclear Information System (INIS)

    The effect of caffeine on radiation-induced chromosomal aberrations and DNA strand breaks in unstimulated human lymphocytes was investigated. When present prior to and during the radiation exposure, caffeine treatment was found to cause either potentiation or protection against induction of chromosomal aberrations depending on the concentration and temperature. When the nucleoid sedimentation technique was applied, enhancement or reduction of radiation-induced DNA strand breaks by caffeine was also found to be dependent on temperature and caffeine concentration. It is proposed that caffeine, in addition to its suspected ability to influence DNA repair, can also influence the induction of DNA damage, leading to alterations in the yield of chromosomal aberrations

  10. Comparative studies of the dose-response relationship of radiation-induced chromosomal aberrations in human lymphocytes induced by low radiation doses, using Feulgen orcein glacial acetic acid and FPG staining

    International Nuclear Information System (INIS)

    Peripheral lymphocytes were exposed in vitro to 220 kV X-radiation, with doses of 0.05, 0.1, 0.2, 0.4, and 0.5 Gy, their culture and preparation was made under standardized conditions. The slides were stained using two different methods, namely FPG staining (fluorescence plus giemsa), and the conventional Feulgen orcein glacial acetic acid method. Compared to the conventional method, FPG staining achieved absolute yields of acentric fragments three times higher, and of dicentric chromosomes twice as high. A linear dose-response relationship in acentric fragments was found by the two staining methods alike, which agrees with the theory. Both staining methods revealed a linear-square dose-response relationship in dicentric chromosomes. Using FPG staining, preparing only M1 cells for evaluation, the linear component was found to be dominant over the whole dose range applied. The conventional method, analysing M1 and M2 cells, revealed the square component to be the most important one. The dose-response relationships determined after FPG staining can be used for biological dosimetry. Calibration can be improved by increasing the number of cells analysed at doses <=0.1 Gy. (orig./MG)

  11. Relationship of chromosomal damage induced by caffeine to growth temperature and ATP level in proliferating cells.

    Science.gov (United States)

    Hernández, P; Mingo, R; González-Fernández, A; López-Sáez, J F

    1986-10-01

    Caffeine is known to induce chromosomal aberrations in proliferating cells when they are incubated during G2 and mitotic prophase. In the present paper, this caffeine effect has been analyzed in Allium cepa root meristems growing at different culture temperatures under steady-state kinetics. Caffeine (1-10 mM) induces chromosomal aberrations in a dose-dependent manner, and the treatment efficiency correlates linearly with the square of caffeine concentration. The efficiency of caffeine incubations, within the range 5-25 degrees C during equivalent cycle time periods has also been studied. It has been found that the lower the culture temperature, the higher the level of chromosomal aberrations. Moreover, at different temperatures, the level of chromosomal aberrations is a simple function of caffeine concentration and the ATP level. Therefore, the efficiency of caffeine treatment appears to be determined by some interaction between caffeine concentration and cellular ATP level. Our present results demonstrate that the influence of growth temperature on the chromosome-breaking effect of caffeine can be, at least partially, explained by the ATP levels during the incubation periods. In short, under different kinetics of plant cell proliferation, the ATP level, and/or something correlating with it, could explain the efficiency of caffeine in inducing chromosomal aberrations: the lower the ATP level, the higher the caffeine efficiency. PMID:3773927

  12. Induction of chromosome aberrations, sister chromatid exchanges and specific locus mutations by radiation and chemicals, and the application of the studies to population monitoring and risk estimation

    International Nuclear Information System (INIS)

    The major portion of the research of the Mammalian Cytogenetics Group can be considered to be directed towards estimating the genetic risk, and potentially the carcinogenicity, of radiation and chemical exposures to man. The approach taken is to attempt to determine the mechanism of induction of chromosome aberrations, sister chromatid exchanges and specific locus mutations, and to apply the information obtained to the interpretation of data from currently used assay systems, or for the development of new, more sensitive, or more predictive, assays. This report is divided into several sections, each one representing a separate series of experiments. There is a logical progression to the sections, and there is a clear relationship between them. The sections are: (1) x-ray-induced chromosome aberrations and the involvement of repair of DNA base damage; (2) hypothesis for the mechanism of induction of chromosome aberrations; (3) the induction of chromosome aberrations in lymphocytes from Down's syndrome individuals; (4) the induction of chromosome aberrations by chemical agents; (5) interactive effects of radiation and chemical agents; (6) risk estimation and population monitoring; (7) the mechanism of induction of sister chromatid exchanges and specific locus mutations; and (8) studies with a transplantable mouse myeloid leukemia - an animal model. The intention of these studies is to improve our ability to extrapolate from data obtained with laboratory animals to the likely outcome in man, in order to provide estimates of the genetic, and potentially the carcinogenic, risk to man from exposures to radiation and chemical agents. There are several studies that have been recently initiated but are not reported here because of limited results so far. These particularly involve the development or improvement of assay systems to provide a greater predictive value or greater sensitivity

  13. Induction of Chromosomal Aberrations at Fluences of Less Than One HZE Particle per Cell Nucleus

    Science.gov (United States)

    Hada, Megumi; Chappell, Lori J.; Wang, Minli; George, Kerry A.; Cucinotta, Francis A.

    2014-01-01

    The assumption of a linear dose response used to describe the biological effects of high LET radiation is fundamental in radiation protection methodologies. We investigated the dose response for chromosomal aberrations for exposures corresponding to less than one particle traversal per cell nucleus by high energy and charge (HZE) nuclei. Human fibroblast and lymphocyte cells where irradiated with several low doses of <0.1 Gy, and several higher doses of up to 1 Gy with O (77 keV/ (long-s)m), Si (99 keV/ (long-s)m), Fe (175 keV/ (long-s)m), Fe (195 keV/ (long-s)m) or Fe (240 keV/ (long-s)m) particles. Chromosomal aberrations at first mitosis were scored using fluorescence in situ hybridization (FISH) with chromosome specific paints for chromosomes 1, 2 and 4 and DAPI staining of background chromosomes. Non-linear regression models were used to evaluate possible linear and non-linear dose response models based on these data. Dose responses for simple exchanges for human fibroblast irradiated under confluent culture conditions were best fit by non-linear models motivated by a non-targeted effect (NTE). Best fits for the dose response data for human lymphocytes irradiated in blood tubes were a NTE model for O and a linear response model fit best for Si and Fe particles. Additional evidence for NTE were found in low dose experiments measuring gamma-H2AX foci, a marker of double strand breaks (DSB), and split-dose experiments with human fibroblasts. Our results suggest that simple exchanges in normal human fibroblasts have an important NTE contribution at low particle fluence. The current and prior experimental studies provide important evidence against the linear dose response assumption used in radiation protection for HZE particles and other high LET radiation at the relevant range of low doses.

  14. Study on the cytotoxicity and chromosome aberration following implantation of sea coral in rabbits

    Directory of Open Access Journals (Sweden)

    Kannan TP

    2006-03-01

    Full Text Available Coral has been used as a bone substitute in many experimental studies. It has been proven to be biocompatible, biodegradable and easy to handle: and it has not been found to cause any inflammatory responses. The present study was undertaken to determine the cytotoxicity in terms of mitotic index as well as the clastogenic effect (chromosome aberration of sea coral implantation in rabbits. The animals comprised of five male adult healthy New Zealand White (Oryctolagus cuniculus rabbits. The biomaterial, sea coral granules used in this study was obtained from Porites species and processed by the tissue bank of Universiti Sains Malaysia, Health Campus, Kubang Kerian, Malaysia. The blood samples were collected twice from the rabbits, once before the implantation of the sea coral granules (which acted as the control and the other, one week after the implantation (which acted as the treatment and lymphocyte cultures were set up. The cultures were then harvested and the chromosomes were prepared for analysis. The diploid number of chromosomes in the rabbits (Oryctolagus cuniculus was found to be 44. Mean mitotic indices of 3.84 ± 0.54 per cent and 3.76 ± 0.23 per cent were obtained before and after implantation of sea coral granules respectively. There were no structural or numerical chromosomal aberrations observed in both the cases. The mitotic index values and chromosomal analyses in this preliminary study carried out indicate that the biomaterial, sea coral granules is non-cytotoxic and non-clastogenic under the present test conditions.

  15. Prediction of human cell radiosensitivity: Comparison of clonogenic assay with chromosome aberrations scored using premature chromosome condensation with fluorescence in situ hybridization

    International Nuclear Information System (INIS)

    The purpose of the present investigation was to determine whether chromosome aberrations scored by premature chromosome condensation (PCC) and fluorescence in situ hybridization (FISH) can predict the radiosensitivity of human cell lines, thereby providing a possible means of assessing the in situ radiosensitivity of normal tissues and the radiocurability of individual human cancers. We used four cells lines of different radiosensitivity: normal human fibroblasts (AG1522), ataxia-telangiectasia fibroblasts (AT2052), a human fibrosarcoma cell line (HT1080), and a human melanoma cell line (melanoma 903). These were irradiated in plateau phase with a range of doses and assessed both for clonogenic cell survival and for aberrations in a single chromosome (number 4) immediately after, and 24 h after irradiation. The initial number of breaks in chromosome 4 was proportional to irradiation dose and was identical for all the different human cell lines, irrespective of radiosensitivity. On the other hand, the number of chromosome 4 breaks remaining 24 h after irradiation reflected the radiosensitivity of the cells such that the relationship between residual chromosome aberrations and cell survival was the same for the different cell lines. These results suggest that the scoring of chromosome aberrations in interphase using FISH with PCC holds considerable promise for predicting the radiosensitivity of normal and tumor tissues in situ. 28 refs., 4 figs

  16. Chromosome aberrations in patients treated by radiotherapy for non-Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Structural chromosome defects were evaluated in the lymphocytes of 30 patients (pts) who had undergone radiotherapy for non Hodgkin's lymphoma (NHL). Twelve had received 20 Grays (Gy) over the abdomen (group I), 12 whole body irradiation at 1,5 Gy (group II) and 6 whole body irradiation at 15 Gy (group III). A cohort of 468 unirradiated pts served as controls. For the irradiated group, 7 % of cells had aberrations compared to 0,4 % in controls (p -6). The frequency of abnormal cells was statistically higher in group I (12 %) than in group II (3,5 %) and III (2,5 %). In group I, frequency of aberrations was statistically higher in pts who had additional extra-abdominal involved field irradiation, those with evolutive NHL and those receiving chemotherapy at the time of the cytogenetic analysis. (authors)

  17. The ATM kinase signaling induced by the low-energy {beta}-particles emitted by {sup 33}P is essential for the suppression of chromosome aberrations and is greater than that induced by the energetic {beta}-particles emitted by {sup 32}P

    Energy Technology Data Exchange (ETDEWEB)

    White, Jason S.; Yue Ning [Department of Radiation Oncology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States); Hu Jing [Department of Pharmacology and Chemical Biology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States); Bakkenist, Christopher J., E-mail: bakkenistcj@upmc.edu [Department of Radiation Oncology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States); Department of Pharmacology and Chemical Biology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States)

    2011-03-15

    Ataxia-telangiectasia mutated (ATM) encodes a nuclear serine/threonine protein kinase whose activity is increased in cells exposed to low doses of ionizing radiation (IR). Here we examine ATM kinase activation in cells exposed to either {sup 32}P- or {sup 33}P-orthophosphate under conditions typically employed in metabolic labelling experiments. We calculate that the absorbed dose of IR delivered to a 5 cm x 5 cm monolayer of cells incubated in 2 ml media containing 1 mCi of the high-energy (1.70 MeV) {beta}-particle emitter {sup 32}P-orthophosphate for 30 min is {approx}1 Gy IR. The absorbed dose of IR following an otherwise identical exposure to the low-energy (0.24 MeV) {beta}-particle emitter {sup 33}P-orthophosphate is {approx}0.18 Gy IR. We show that low-energy {beta}-particles emitted by {sup 33}P induce a greater number of ionizing radiation-induced foci (IRIF) and greater ATM kinase signaling than energetic {beta}-particles emitted by {sup 32}P. Hence, we demonstrate that it is inappropriate to use {sup 33}P-orthophosphate as a negative control for {sup 32}P-orthophosphate in experiments investigating DNA damage responses to DNA double-strand breaks (DSBs). Significantly, we show that ATM accumulates in the chromatin fraction when ATM kinase activity is inhibited during exposure to either radionuclide. Finally, we also show that chromosome aberrations accumulate in cells when ATM kinase activity is inhibited during exposure to {approx}0.36 Gy {beta}-particles emitted by {sup 33}P. We therefore propose that direct cellular exposure to {sup 33}P-orthophosphate is an excellent means to induce and label the IR-induced, ATM kinase-dependent phosphoproteome.

  18. Acquisition of Genetic Aberrations by Activation-Induced Cytidine Deaminase (AID) during Inflammation-Associated Carcinogenesis

    International Nuclear Information System (INIS)

    Genetic abnormalities such as nucleotide alterations and chromosomal disorders that accumulate in various tumor-related genes have an important role in cancer development. The precise mechanism of the acquisition of genetic aberrations, however, remains unclear. Activation-induced cytidine deaminase (AID), a nucleotide editing enzyme, is essential for the diversification of antibody production. AID is expressed only in activated B lymphocytes under physiologic conditions and induces somatic hypermutation and class switch recombination in immunoglobulin genes. Inflammation leads to aberrant AID expression in various gastrointestinal organs and increased AID expression contributes to cancer development by inducing genetic alterations in epithelial cells. Studies of how AID induces genetic disorders are expected to elucidate the mechanism of inflammation-associated carcinogenesis

  19. Comparison of hprt variant frequencies and chromosome aberration frequencies in lymphocytes from radiotherapy and chemotherapy patients: A prospective study

    International Nuclear Information System (INIS)

    The autoradiographic 6-thioguanine-resistant mutant lymphocyte assay and a chromosome aberration assay were used to determine the time-course of appearance and persistence of elevated frequencies of hprt variants and dicentric chromosomes in patients receiving x-irradiation therapy. The hprt mutation assays were done with frozen/thawed lymphocytes isolated from aliquots of the same blood samples used for the chromosome aberration assays. Five multiple sclerosis patients were also studied before and at 2 and 4 wk intervals after treatment with monthly i.v. doses of 750 mg/m2 of cyclophosphamide (CP). There were no significant elevations in chromosome aberrations at these post-treatment sample times. The results demonstrate the complementary nature of these two human monitoring assays and emphasize the importance of careful selection of optimal sampling times

  20. Study of chromosome aberration repair after acute or fractionated X-irradiation in human peripheral lymphocytes

    International Nuclear Information System (INIS)

    Pure human peripheral blood has been subjected to a single irradiation with the dose of 125 and 250R and by fractions with the doses of 125+125 R in the following periods of the cell cycle: 0, 2, 4, 6, 8, 12, 16, 24, 30, 40 and 45 hrs. The following types of structural chromosome aberrations are counted on metaphase plates with a good chromosome scattering: dicentrics, rings, interstitial deletions, symmetric translocations, chromatide and chromosome fragments. The data on polycentrics and rings prove to be most characteristic: the frequency of these aberrations in the case of single irradiation for all periods of the ''presynthetic'' Gsub(I) period is stable varying in the range of 17-20% in the case of a 125 R dose and 66-73% in the case of a 250 R dose. Their frequency decreased for both doses of irradiation in later periods and reached 1% by the end of the synthetic period. The fractionated effect of two doses 125 R each gives the following values of polycentric and ring formation: second hour - 44,15%, fourth - 50,82%, sixth - 55,15% eighth -58,32% (maximum), twelfth - 55,48%. The descending tendency is preserved till the end of the presynthetic period and in the synthetic period. The statistic processing of results shows statistically authentic differences between fractionated and single irradiation in the output of polycentrics and rings, as well as other types of aberrations and breaks per cell. The data obtained permit to conclude that repair processes are undulatory and are characterized by maximum intensity in the first hours of presynthetic period which weakens to the 8th hour and then strengthens again almost to the end of the synthetic period

  1. The induction of SCE and chromosomal aberrations with relation to specific base methylation of DNA in Chinese hamster cells by N-methyl-N-nitrosourea and dimethyl sulphate.

    Science.gov (United States)

    Connell, J R; Medcalf, A S

    1982-01-01

    Chinese hamster cells (V79) were treated, either as exponentially proliferating cultures or under conditions where they were density-inhibited, with various doses of the potent carcinogen N-methyl-N-nitrosourea (MNU) or the relatively weak carcinogen dimethylsulphate (DMS). The colony forming ability of these cells and the induced frequencies of sister chromatid exchanges (SCEs) and chromosomal aberrations were assayed. Following the exposure of density-inhibited cells to radio-labelled methylating agents (labelled in the methyl group) these phenomena were related to the levels of 7-methylguanine (7-meGua), O6-methylguanine (O6-meGua) and 3-methyladenine (3-me-Ade) in the DNA. At equitoxic doses MNU and DMS induced similar frequencies of SCEs and chromosomal aberrations. Since, at equitoxic doses, MNU produces approximately 20 times more O6-meGua in V79 cell DNA than does DMS, this indicates that the formation of O6-meGua in DNA is not a major cause of SCEs and chromosomal aberrations. DMS-induced SCEs may be mediated via the production of both 3-meAde and 7-meGua in the DNA; these two methylated purines may also be responsible for MNU-induced SCEs. Therefore, no one specific methylated purine was identified as being solely accountable for the formation of SCEs. Also, the repair of lesions in the DNA of non-replicating V79 cells leads to a reduction in the SCE frequency on their subsequent release from the density-inhibited state, suggesting that repair is not intimately responsible for their formation. No association was discernable between chromosomal aberrations and any of the three methylated purines studied. PMID:7094205

  2. Radiation-induced chromosome breakages in bread wheat (Triticum aestivum L.)

    International Nuclear Information System (INIS)

    Meiosis and pollen fertility were studied in the M2 generation in four varieties of hexaploid wheat. Meiosis was characterized by the formation of interchange configurations, such as rings and chains of four chromosomes in several cells. Chromosomal aberrations showed linear relationship with gamma irradiation; 45 kR dose induced the highest chromosomal abnormalities. Most multivalents were interchange rings of four chromosomes. Translocations involving two pairs of homologous or nonhomologous chromosomes seemed to be higher in frequency than those involving more than two pairs of chromosomes. Anaphase abnormalities, such as laggards, bridges and fragments and unequal segregation of chromosomes, were frequently observed. Pollen fertility was considerably reduced in the M2 plants arising form the treatments of higher doses of gamma rays because of the induced chromosome interchanges. (author)

  3. Chromosomal aberrations in environmentally exposed population in relation to metabolic and DNA repair genes polymorphisms

    Czech Academy of Sciences Publication Activity Database

    Šrám, Radim; Beskid, Olena; Binková, Blanka; Chvátalová, Irena; Lněničková, Zdena; Milcová, Alena; Solanský, I.; Tulupová, Elena; Bavorová, H.; Ocadlíková, D.; Farmer, P. B.

    2007-01-01

    Roč. 620, - (2007), s. 22-33. ISSN 0027-5107 R&D Projects: GA MŽP SI/340/2/00; GA MŽP SL/740/5/03; GA MŽP SL/5/160/05 Grant ostatní: EU(GB) 2000-00091 Institutional research plan: CEZ:AV0Z50390512 Source of funding: R - rámcový projekt EK Keywords : chromosomal aberrations * cytogenetic analysis * carcinogenic PAHs Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 4.159, year: 2007

  4. Comparison of RBE values of high- LET α-particles for the induction of DNA-DSBs, chromosome aberrations and cell reproductive death

    International Nuclear Information System (INIS)

    Various types of radiation effects in mammalian cells have been studied with the aim to predict the radiosensitivity of tumours and normal tissues, e.g. DNA double strand breaks (DSB), chromosome aberrations and cell reproductive inactivation. However, variation in correlations with clinical results has reduced general application. An additional type of information is required for the increasing application of high-LET radiation in cancer therapy: the Relative Biological Effectiveness (RBE) for effects in tumours and normal tissues. Relevant information on RBE values might be derived from studies on cells in culture. To evaluate relationships between DNA-DSB, chromosome aberrations and the clinically most relevant effect of cell reproductive death, for ionizing radiations of different LET, dose-effect relationships were determined for the induction of these effects in cultured SW-1573 cells irradiated with gamma-rays from a Cs-137 source or with α-particles from an Am-241 source. RBE values were derived for these effects. Ionizing radiation induced foci (IRIF) of DNA repair related proteins, indicative of DSB, were assessed by counting gamma-H2AX foci. Chromosome aberration frequencies were determined by scoring fragments and translocations using premature chromosome condensation. Cell survival was measured by colony formation assay. Analysis of dose-effect relations was based on the linear-quadratic model. Our results show that, although both investigated radiation types induce similar numbers of IRIF per absorbed dose, only a small fraction of the DSB induced by the low-LET gamma-rays result in chromosome rearrangements and cell reproductive death, while this fraction is considerably enhanced for the high-LET alpha-radiation. Calculated RBE values derived for the linear components of dose-effect relations for gamma-H2AX foci, cell reproductive death, chromosome fragments and colour junctions are 1.0 ± 0.3, 14.7 ± 5.1, 15.3 ± 5.9 and 13.3 ± 6.0 respectively

  5. Comparison of RBE values of high- LET α-particles for the induction of DNA-DSBs, chromosome aberrations and cell reproductive death

    Directory of Open Access Journals (Sweden)

    Aten Jacob

    2011-06-01

    Full Text Available Abstract Background Various types of radiation effects in mammalian cells have been studied with the aim to predict the radiosensitivity of tumours and normal tissues, e.g. DNA double strand breaks (DSB, chromosome aberrations and cell reproductive inactivation. However, variation in correlations with clinical results has reduced general application. An additional type of information is required for the increasing application of high-LET radiation in cancer therapy: the Relative Biological Effectiveness (RBE for effects in tumours and normal tissues. Relevant information on RBE values might be derived from studies on cells in culture. Methods To evaluate relationships between DNA-DSB, chromosome aberrations and the clinically most relevant effect of cell reproductive death, for ionizing radiations of different LET, dose-effect relationships were determined for the induction of these effects in cultured SW-1573 cells irradiated with gamma-rays from a Cs-137 source or with α-particles from an Am-241 source. RBE values were derived for these effects. Ionizing radiation induced foci (IRIF of DNA repair related proteins, indicative of DSB, were assessed by counting gamma-H2AX foci. Chromosome aberration frequencies were determined by scoring fragments and translocations using premature chromosome condensation. Cell survival was measured by colony formation assay. Analysis of dose-effect relations was based on the linear-quadratic model. Results Our results show that, although both investigated radiation types induce similar numbers of IRIF per absorbed dose, only a small fraction of the DSB induced by the low-LET gamma-rays result in chromosome rearrangements and cell reproductive death, while this fraction is considerably enhanced for the high-LET alpha-radiation. Calculated RBE values derived for the linear components of dose-effect relations for gamma-H2AX foci, cell reproductive death, chromosome fragments and colour junctions are 1.0 ± 0.3, 14

  6. Chromosomal aberrations in a fish, Channa punctata after in vivo exposure to three heavy metals.

    Science.gov (United States)

    Yadav, Kamlesh K; Trivedi, Sunil P

    2009-08-01

    The studies were designed to assess the extent of chromosomal aberrations (CA) under the exposure of three common heavy metalic compounds, viz. mercuric chloride, arsenic trioxide and copper sulphate pentahydrate, in vivo using fish, Channa punctata (2n=32), as a test model. Prior acclimatized fishes were divided into five groups. Group I and II served as negative and positive control, respectively. An intramuscular injection of Mitomycin-C (@ 1mg/kg body wt.) was administered to group II only. Fishes of groups III, IV and V were subjected to sublethal concentrations (10% of 96h LC(50)), of HgCl(2) (0.081mg/L), As(2)O(3) (6.936mg/L) and CuSO(4)x5H(2)O (0.407mg/L). Fishes of all the groups were exposed uninterrupted for 24, 48, 72, 96 and 168h. Observations of kidney cells of exposed fishes revealed chromatid and chromosome breaks, chromatid and chromosome gaps along with ring and di-centric chromosomes. A significant increase over negative control in the frequency of chromosomal aberrations (CA) was observed in fish exposed to Mitomycin-C, Hg(II), As(III) and Cu(II). As the average + or - SE total number of CA, average number of CA per metaphase and %incidence of aberrant cells in Hg(II) was 104.40 + or - 8.189, 0.347 + or - 0.027 and 10.220 + or - 0.842, respectively; in As(III) 109.20 + or - 8.309, 0.363 + or - 0.027 and 10.820 + or - 2.347, respectively and in Cu(II) 89.00 + or - 19.066, 0.297 + or - 0.028 and 8.900 + or - 0.853, respectively. Hence, it reveals that the order of induction of frequency of CA was Cu

  7. Sharpness changes of gaussian beams induced by spherically aberrated lenses

    Science.gov (United States)

    Piquero, G.; Mejías, P. M.; Martínez-Herrero, R.

    1994-04-01

    Sharpness changes of the spatial profile of a gaussian beam induced by spherically aberrated lenses are investigated in terms of the so-called kurtosis parameter. It is shown both theoretically and experimentally that, after a single aberrated lens, it is possible to get flatter and sharper beam intensity distributions than the input gaussian beam depending on the plane where the field is observed. Agreement between analytical and experimental results is discussed.

  8. Morphological images analysis and chromosomic aberrations classification based on fuzzy logic

    International Nuclear Information System (INIS)

    This work has implemented a methodology for automation of images analysis of chromosomes of human cells irradiated at IEA-R1 nuclear reactor (located at IPEN, Sao Paulo, Brazil), and therefore subject to morphological aberrations. This methodology intends to be a tool for helping cytogeneticists on identification, characterization and classification of chromosomal metaphasic analysis. The methodology development has included the creation of a software application based on artificial intelligence techniques using Fuzzy Logic combined with image processing techniques. The developed application was named CHRIMAN and is composed of modules that contain the methodological steps which are important requirements in order to achieve an automated analysis. The first step is the standardization of the bi-dimensional digital image acquisition procedure through coupling a simple digital camera to the ocular of the conventional metaphasic analysis microscope. Second step is related to the image treatment achieved through digital filters application; storing and organization of information obtained both from image content itself, and from selected extracted features, for further use on pattern recognition algorithms. The third step consists on characterizing, counting and classification of stored digital images and extracted features information. The accuracy in the recognition of chromosome images is 93.9%. This classification is based on classical standards obtained at Buckton [1973], and enables support to geneticist on chromosomic analysis procedure, decreasing analysis time, and creating conditions to include this method on a broader evaluation system on human cell damage due to ionizing radiation exposure. (author)

  9. Induction of chromosome aberrations in rabbit lymphocytes by low doses of X-rays and neutrons

    International Nuclear Information System (INIS)

    The induction of dicentric aberrations has been studied in rabbit lymphocytes after exposure to low doses of X-rays or d(50)+Be neutrons. The aberrations have been analysed in first division cells collected after a 32 h culture time. In both cases, the dose response relationship is best fitted to a linear-quadratic model. Rabbit lymphocytes are less radiosensitive than human lymphocytes and RBE is lower in rabbit than in human cells. These discrepancies could be due to differences in the repair capacities for the lesions induced by X-rays and neutrons in rabbit and human lymphocytes

  10. Comparison of the effectiveness of different radiations for the induction of reproductive death, chromosome aberrations, morphological transformations and specific mutations in cultured mammalian cells

    International Nuclear Information System (INIS)

    Ionizing radiations can induce a variety of changes in cultured mammalian cells, many of which are initiated by damage to the chromosomes. If the primary mechanisms of damage at the molecular level are similar, it can be expected that dose-effect relationships for the different cellular responses should exhibit common characteristics. A comparison of dose-effect relationships has been made for published data on several types of cells treated with radiations of different Linear Energy Transfer (LET) and assessed with respect to two or more endpoints. Various types of cells have different sensitivities to low LET as well as to high LET radiation and cellular effects are induced at different frequencies per unit dose. Cell reproductive death and chromosome aberrations can presumably be induced as a result of damage in any one of the chromosomes. Chromosome breaks leading to deletions may occur at many sites. The probability of breaks may not be uniform along chromosomes, but this is difficult to establish. Cell transformation is more frequently (30 to 1000 times) induced by ionizing radiations than specific gene mutations and it may therefore be inferred that many, if not all, chromosomes contain one or more sites with genes which, if damaged, deleted or transposed to another site, may cause morphological malignant transformation. (Auth./C.F.)

  11. Genotoxicity evaluation of dental restoration nanocomposite using comet assay and chromosome aberration test

    International Nuclear Information System (INIS)

    Nanocomposite is used as a dental filling to restore the affected tooth, especially in dental caries. The dental nanocomposite (KelFil) for tooth restoration used in this study was produced by the School of Dental Sciences, Universiti Sains Malaysia, Malaysia and is incorporated with monodispersed, spherical nanosilica fillers. The aim of the study was to determine the genotoxic effect of KelFil using in vitro genotoxicity tests. The cytotoxicity and genotoxicity of KelFil was evaluated using MTT assay, comet assay and chromosome aberration tests with or without the addition of a metabolic activation system (S9 mix), using the human lung fibroblast cell line (MRC-5). Concurrent negative and positive controls were included. In the comet assay, no comet formation was found in the KelFil groups. There was a significant difference in tail moment between KelFil groups and positive control (p < 0.05). Similarly, no significant aberrations in chromosomes were noticed in KelFil groups. The mitotic indices of treatment groups and negative control were significantly different from positive controls. Hence, it can be concluded that the locally produced dental restoration nanocomposite (KelFil) is non-genotoxic under the present test conditions. (paper)

  12. Genotoxicity evaluation of dental restoration nanocomposite using comet assay and chromosome aberration test

    Science.gov (United States)

    Musa, Marahaini; Thirumulu Ponnuraj, Kannan; Mohamad, Dasmawati; Rahman, Ismail Ab

    2013-01-01

    Nanocomposite is used as a dental filling to restore the affected tooth, especially in dental caries. The dental nanocomposite (KelFil) for tooth restoration used in this study was produced by the School of Dental Sciences, Universiti Sains Malaysia, Malaysia and is incorporated with monodispersed, spherical nanosilica fillers. The aim of the study was to determine the genotoxic effect of KelFil using in vitro genotoxicity tests. The cytotoxicity and genotoxicity of KelFil was evaluated using MTT assay, comet assay and chromosome aberration tests with or without the addition of a metabolic activation system (S9 mix), using the human lung fibroblast cell line (MRC-5). Concurrent negative and positive controls were included. In the comet assay, no comet formation was found in the KelFil groups. There was a significant difference in tail moment between KelFil groups and positive control (p < 0.05). Similarly, no significant aberrations in chromosomes were noticed in KelFil groups. The mitotic indices of treatment groups and negative control were significantly different from positive controls. Hence, it can be concluded that the locally produced dental restoration nanocomposite (KelFil) is non-genotoxic under the present test conditions.

  13. Persistence of unstable and stable chromosome aberrations in lymphocytes of cancer patients treated with radiotherapy

    International Nuclear Information System (INIS)

    Background: Radiation-induced DNA damage in human lymphocytes has equal probability of producing both stable or unstable chromosome aberrations (C.A.). Reports of its in vivo persistence show considerable variations. The quantification of unstable C.A. (dicentrics) in peripheral blood lymphocytes (P.B.L.) is the most reliable biological method for estimating whole-body doses of recent overexposures to ionizing radiation. Given that during the division of T cell precursors, proliferative death of cells containing dicentrics reduces the number of such lymphocytes in peripheral blood, dicentric methodology should be modified to account for past exposures. Micronuclei (M.N.) in cytokinesis-blocked human P.B.L. are well established bio markers for assessing radiation damage in vivo. However, persistence of radiation induced M.N. is limited. Unlike dicentrics and M.N., stable C.A. (translocations) identified at present by the FISH technique, seem to be an adequate indicator for the dosimetric evaluation of past exposures, since translocations are not selected against during mitotic division in the haematopoietic stem cells compartment. Nevertheless, for partial -body exposures with high dose there is some evidence that the decline with time of dicentrics causes some reduction in the yield of translocations. Purpose: To assess the persistence along time of dicentrics, M.N. and translocations in lymphocytes of cancer patients after radiotherapy in order to model changes in C.A. frequencies with partial-body exposures. Materials and methods: 22 cancer patients with different tumor sites, treated with radiotherapy, were evaluated through dicentric chromosome, M.N. and FISH techniques with a follow-up time of up to 90 months after the end of radiotherapy. Regression analysis were performed: 1) for dicentric and for M.N. frequencies in relation to time after the end of radiotherapy and total tumor dose; 2) for the percentage of uns table cells in relation to time after the end

  14. Influence of age and gender in response to {gamma}-radiation in Portuguese individuals using chromosomal aberration assay - Preliminary findings

    Energy Technology Data Exchange (ETDEWEB)

    Martins, V.; Antunes, A.C. [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Dosimetry and Radiobiology Group, E.N. 10, Apartado 21, 2686-953 Sacavem (Portugal); Cardoso, J.; Santos, L. [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Metrology Laboratory of Ionizing Radiation, E.N. 10, Apartado 21, 2686-953 Sacavem (Portugal); Gil, O. Monteiro, E-mail: octavia.gil@itn.pt [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Dosimetry and Radiobiology Group, E.N. 10, Apartado 21, 2686-953 Sacavem (Portugal)

    2011-09-15

    Cytogenetic indicators are widely used in radiobiology to evaluate effects of ionizing radiation since dicentric chromosomes (Dic) are almost exclusively induced by ionizing radiation, and spontaneous frequency of Dic is very low in the healthy general population (about one Dic per 1000 cells). A particular interest of biodosimetry has been not only to obtain absorbed dose estimates using adequate calibration curves, under the assumption that all individuals respond equally to radiation-induced chromosome aberrations, but also to find a way to demonstrate inter-individual radiosensitivity and a possible correlation with age and gender. Thus, the objective of this preliminary work was the evaluation of the influence of age and gender on the outcome of cytogenetic biomarkers after {gamma}-irradiation. Samples of peripheral blood lymphocytes from six healthy, non-smoker, donors from both genders (three men and three women), in the range of 20 to 49 years, were irradiated with doses from 0 Gy to 3 Gy air kerma, using a {sup 60}Co gamma rays source with a dose rate from 170-180 mGy/min. A clear dose-dependent increase in terms of aberrant cells excluding gaps (ACEG) and Dic was observed for all donors. Our preliminary results suggest, in the higher dose level evaluated (3 Gy), a larger intervariability among individuals for Dic, with females apparently more sensitive than males (P<0.05). Considering the different age groups, male donors showed a decrease, with age, for Dic and ACEG at the higher dose and also, for the background level, in case of ACEG. Future work will consider the study of more individuals, from both genders and different ages, in order to verify if this tendency persists and to enable the implementation of a dose-response calibration curve at Instituto Tecnologico e Nuclear for the Portuguese population, to quantify the biological dose in case of a radiological accident or emergency.

  15. Influence of age and gender in response to γ-radiation in Portuguese individuals using chromosomal aberration assay - Preliminary findings

    International Nuclear Information System (INIS)

    Cytogenetic indicators are widely used in radiobiology to evaluate effects of ionizing radiation since dicentric chromosomes (Dic) are almost exclusively induced by ionizing radiation, and spontaneous frequency of Dic is very low in the healthy general population (about one Dic per 1000 cells). A particular interest of biodosimetry has been not only to obtain absorbed dose estimates using adequate calibration curves, under the assumption that all individuals respond equally to radiation-induced chromosome aberrations, but also to find a way to demonstrate inter-individual radiosensitivity and a possible correlation with age and gender. Thus, the objective of this preliminary work was the evaluation of the influence of age and gender on the outcome of cytogenetic biomarkers after γ-irradiation. Samples of peripheral blood lymphocytes from six healthy, non-smoker, donors from both genders (three men and three women), in the range of 20 to 49 years, were irradiated with doses from 0 Gy to 3 Gy air kerma, using a 60Co gamma rays source with a dose rate from 170-180 mGy/min. A clear dose-dependent increase in terms of aberrant cells excluding gaps (ACEG) and Dic was observed for all donors. Our preliminary results suggest, in the higher dose level evaluated (3 Gy), a larger intervariability among individuals for Dic, with females apparently more sensitive than males (P<0.05). Considering the different age groups, male donors showed a decrease, with age, for Dic and ACEG at the higher dose and also, for the background level, in case of ACEG. Future work will consider the study of more individuals, from both genders and different ages, in order to verify if this tendency persists and to enable the implementation of a dose-response calibration curve at Instituto Tecnologico e Nuclear for the Portuguese population, to quantify the biological dose in case of a radiological accident or emergency.

  16. Analysis of chromosomal aberrations of leukocytes of peripheric blood in patients with depression of different genesis hematopoiesis

    International Nuclear Information System (INIS)

    Cytogenic investigations were carried on to reveal the increase in the aberration cell content as compared to the spontaneous level in 30 patients. The least quantity of the cells were in patients exposed to radiotherapy (6-14%), the greatest - in patients subjected to the combined treatment (radio- and chemotherapies). All the patients had structural changes in chromosomes and the primary type of aberrations was a chromosomal one. The group of patients subjected to chemotherapy before leukopenia had aberrations of the chromatid type (16.4%). It is concluded that leukopenias result from structural and quantitative changes in the chromosomal apparatus of leukocytes in patients under the effect of mutagenous factors on the organism

  17. Thyroid nodularity and chromosome aberrations among women in areas of high background radiation in China

    International Nuclear Information System (INIS)

    Thyroid nodularity following continuous low-dose radiation exposure in China was determined in 1,001 women aged 50-65 years who resided in areas of high background radiation (330 mR/yr) their entire lives, and in 1,005 comparison subjects exposed to normal levels of radiation (114 mR/yr). Cumulative doses to the thyroid were estimated to be of the order of 14 cGy and 5 cGy, respectively. Personal interviews and physical examinations were conducted, and measurements were made of serum thyroid hormone levels, urinary iodine concentrations, and chromosome aberrations in circulating lymphocytes. For all nodular disease, the prevalences in the high background and control areas were 9.5% and 9.3%, respectively. For single nodules, the prevalences were 7.4% in the high background area and 6.6% in the control area (prevalence ratio = 1.13; 95% confidence interval = 0.82-1.55). There were no differences found in serum levels of thyroid hormones. Women in the high background region, however, had significantly lower concentrations of urinary iodine and significantly higher frequencies of stable and unstable chromosome aberrations. Increased intake of allium vegetables such as garlic and onions was associated with a decreased risk of nodular disease, which seems consistent with experimental studies suggesting that allium compounds can inhibit tumor growth and proliferation. The prevalence of mild diffuse goiter was higher in the high background radiation region, perhaps related to a low dietary intake of iodine. These data suggest that continuous exposure to low-level radiation throughout life is unlikely to appreciably increase the risk of thyroid cancer. However, such exposure may cause chromosomal damage

  18. Role of the diet in ontogenesis and induction of chromosomal aberrations in population living in the area exposed to radioactive contamination

    International Nuclear Information System (INIS)

    The objective of this work is to investigate a role of diet in oncogenesis and induction of chromosomal aberrations in fragility sites in the peripheral blood lymphocytes of people in some areas exposed to radionuclides as a result of an accident in the Siberian Chemical Combine (SCP). The purpose of the present study was to investigate the level of aberrations at fragile sites of chromosomes in peripheral blood lymphocytes of population residing area contaminated with radionuclides following an accident at the Siberian Chemical Plant (SCP). We carried out micronucleus test to screen people with radiation-related cytogenetic effects. Of 1246 examined inhabitants of Samus settlement, 148 showed significantly increased frequency of micronucleated erythrocytes and were selected for chromosome analysis as a radiation-exposed group. Additional analysis was carried out for 40 patients with gastric cancer and atrophic gastritis with stage II-III epithelial dysplasia. Eighty six individuals from non-contaminated area were used as a control group. Chromosomal breaks and exchanges occurred preferentially in chromosomes 3 and 6 among radiation-exposed persons and patients. The regions 3pl4-3p25 and 6p23 were damaged most often. There was a tendency towards preferential involvement at q21-q25 of chromosome 6 in patients with gastric cancer and atrophic gastritis. Specific damage at certain chromosome sites was observed in radiation-exposed population as well as in patients with gastric cancer. Most often this damage was located near oncogene loci which could imply that chromosome damage induced by radiation is likely to be a predisposing factor to the expression of oncogenes and malignant transformation of cells in exposed individuals. (author)

  19. Chromosome aberration and hematological rates of gastropod snail (Lymnaea stagnalis L.) in water bodies of the Chernobyl NPP exclusion zone

    International Nuclear Information System (INIS)

    The radiation dose, as well as the chromosome aberration rate and a change of the hemolymph structure of the gastropod snail (Lymnaea stagnalis L.) in water bodies within the Chernobyl NPP exclusion Zone during 1998-2007, is evaluated. The absorbed dose is registered in range 0.3-85.0 μGy/h. In closed water bodies, the high rate of chromosome aberration in embryo tissues (up to 27%) and essential changes of hematological rates of adult molluscs in comparison with those in control water bodies are determined.

  20. Computer aided analysis of additional chromosome aberrations in Philadelphia chromosome positive acute lymphoblastic leukaemia using a simplified computer readable cytogenetic notation

    OpenAIRE

    Mohr Brigitte; Jauch Anna; Heinze Barbara; Fonatsch Christa; Balz Harald; Bradtke Jutta; Schoch Claudia; Rieder Harald

    2003-01-01

    Abstract Background The analysis of complex cytogenetic databases of distinct leukaemia entities may help to detect rare recurring chromosome aberrations, minimal common regions of gains and losses, and also hot spots of genomic rearrangements. The patterns of the karyotype alterations may provide insights into the genetic pathways of disease progression. Results We developed a simplified computer readable cytogenetic notation (SCCN) by which chromosome findings are normalised at a resolution...

  1. Dose Response for Chromosome Aberrations in Human Lymphocytes and Fibroblasts After Exposure to Very Low Dose of High Let Radiation

    Science.gov (United States)

    Hada, M.; George, K.; Chappell, L.; Cucinotta, F. A.

    2011-01-01

    The relationship between biological effects and low doses of absorbed radiation is still uncertain, especially for high LET radiation exposure. Estimates of risks from low-dose and low-dose-rates are often extrapolated using data from Japanese atomic bomb survivor with either linear or linear quadratic models of fit. In this study, chromosome aberrations were measured in human peripheral blood lymphocytes and normal skin fibroblasts cells after exposure to very low dose (0.01 - 0.20 Gy) of 170 MeV/u Si-28 ions or 600 MeV/u Fe-56 ions, including doses where on average less than one direct ion traversal per cell nucleus occurs. Chromosomes were analyzed using the whole-chromosome fluorescence in situ hybridization (FISH) technique during the first cell division after irradiation, and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving >2 breaks in 2 or more chromosomes). The responses for doses above 0.1 Gy (more than one ion traverses a cell) showed linear dose responses. However, for doses less than 0.1 Gy, both Si-28 ions and Fe-56 ions showed a dose independent response above background chromosome aberrations frequencies. Possible explanations for our results are non-targeted effects due to aberrant cell signaling [1], or delta-ray dose fluctuations [2] where a fraction of cells receive significant delta-ray doses due to the contributions of multiple ion tracks that do not directly traverse cell nuclei where chromosome aberrations are scored.

  2. Chromosomal anomalies in radiation-induced fibrosis in the pig

    International Nuclear Information System (INIS)

    R-banded karyotypes were established on fibroblasts from fibrotic tissues derived from experimental fibrosis induced in pigs, either surgically or by 64 Gy of γ-rays from iridium-192. No chromosome aberrations were observed in the surgical fibrosis. In radiation-induced fibrosis, the high frequency of abnormal karyotypes and frequent complexity of the chromosomal rearrangements suggest that the fibroblasts originated either from the 64-Gy area, or from the penumbra, but certainly not from non-irradiated areas. At early passages in vitro, almost all karyotypes were different, demonstrating a multiclonal origin of fibrotic tissue. At late passages (above 24), the situation was quite different, with the persistence of one or two clones only, demonstrating a strong selective pressure occurring in vitro. (author). 23 refs., 2 figs., 2 tabs

  3. Complex chromosome aberrations as a biomarker of exposure to high-LET α -particles: current validation studies

    International Nuclear Information System (INIS)

    The identification of a biomarker of environmental exposure to radon could enable a causal link between this chronic low-dose high-LET α -particle radiation exposure and the onset of specific health effects, such as cancer, to be established. We have recently characterised such a biomarker, in peripheral blood lymphocytes (PBL) after low dose α -particle irradiation in vitro, using both 3-colour and 24-colour (M)-FISH techniques, terming it as a 'cytogenetic profile of α -particle-induced damage' (Anderson et al., 2000, 2003). In summary, this profile comprises complex chromosome aberrations that are stable and therefore transmissible (predominantly insertions), and also non-transmissible complexes, recently shown to be qualitatively specific of the damage produced by the direct nuclear traversal of a single α -particle (Anderson et al., 2002). To test the validity and practical usefulness of such a biomarker, we have compared the complexity and type of aberrations observed in individuals occupationally exposed to internal α -emitting radionuclides with those who have received only external γ or mixed α - and γ -irradiation. Non-exposed regional controls were also assessed. M-FISH analysis of ∼1000 cells shows that complex aberrations (transmissible and non-transmissible) consistent with those observed in vitro are a common feature in the α -particle exposed group. Specifically, the proportion of transmissible complexes ranged from 25 to 64%, demonstrating that transmissible-type complexes are induced in vivo and therefore could be relevant indicators of past exposures. Similarly, the detection of non-transmissible complexes, is an indicator of recently 'hit' PBL and therefore on-going or chronic exposure to α -particles. To further validate this biomarker of exposure we are currently using M-FISH to examine the complexity and transmissibility of α -particle-induced aberrations in primitive cells that are hierarchical to PBL and which have self

  4. High resistance of fibroblasts from Mongolian gerbil embryos to cell killing and chromosome aberrations by X-irradiation

    International Nuclear Information System (INIS)

    Mongolian gerbil (Meriones unguiculatus) is known to be one of the most radioresistant animal species. In order to determine whether there is any correlation between mortality of mammals exposed to γ- or X-rays and radiation sensitivity of culture cells derived from different mammalian species, we have examined the X-ray survival curves of normal diploid fibroblasts from Mongolian gerbil embryos and compared with those of other cultured embryo cells from various laboratory animals and normal human. There was a big difference in cell survival to X-rays among different mammalian species. The D0 values of Mongolian gerbil cells ranged from 2.3 to 2.6 Gy which are twice as high as those of human cells. The mean D0 value of human cells was 1.1 Gy. Mouse, rat, Chinese hamster and Syrian/golden hamster cells showed similar D0 values ranging from 1.7 to 2.0 Gy. When cells were irradiated with 2 Gy of X-rays, three times longer mitotic delay was observed in human cells than in Mongolian gerbil cells. At this X-ray dose, furthermore, ten times more chromosome aberrations were detected in human cells than in Mongolian gerbil cells, and the frequencies of other rodent cells lay between the values for the two cell strains. These data indicate that the Mongolian gerbil cells are resistant to X-ray-induced cell killing and chromosome aberrations, and that radiation sensitivity of primarily cultured mammalian cells may be reflected by their radioresistance in vivo. (author)

  5. Space Radiation Effects on Human Cells: Modeling DNA Breakage, DNA Damage Foci Distribution, Chromosomal Aberrations and Tissue Effects

    Science.gov (United States)

    Ponomarev, A. L.; Huff, J. L.; Cucinotta, F. A.

    2011-01-01

    Future long-tem space travel will face challenges from radiation concerns as the space environment poses health risk to humans in space from radiations with high biological efficiency and adverse post-flight long-term effects. Solar particles events may dramatically affect the crew performance, while Galactic Cosmic Rays will induce a chronic exposure to high-linear-energy-transfer (LET) particles. These types of radiation, not present on the ground level, can increase the probability of a fatal cancer later in astronaut life. No feasible shielding is possible from radiation in space, especially for the heavy ion component, as suggested solutions will require a dramatic increase in the mass of the mission. Our research group focuses on fundamental research and strategic analysis leading to better shielding design and to better understanding of the biological mechanisms of radiation damage. We present our recent effort to model DNA damage and tissue damage using computational models based on the physics of heavy ion radiation, DNA structure and DNA damage and repair in human cells. Our particular area of expertise include the clustered DNA damage from high-LET radiation, the visualization of DSBs (DNA double strand breaks) via DNA damage foci, image analysis and the statistics of the foci for different experimental situations, chromosomal aberration formation through DSB misrepair, the kinetics of DSB repair leading to a model-derived spectrum of chromosomal aberrations, and, finally, the simulation of human tissue and the pattern of apoptotic cell damage. This compendium of theoretical and experimental data sheds light on the complex nature of radiation interacting with human DNA, cells and tissues, which can lead to mutagenesis and carcinogenesis later in human life after the space mission.

  6. Radiation induced chromosome instability in human fibroblasts

    International Nuclear Information System (INIS)

    Evidence has been arising that some biological effects can manifest many cell divisions after irradiation. We have demonstrated that de novo chromosome instability can be detected 10- 15 mean population doubling after heavy ion irradiations. This chromosome instability is characterized by end to end fusions between specific chromosomes. The specificity of the instability may differ from one donor to another but for the same donor, the same instability should be observed after irradiation, during the senescence process and after SV40 transfection (before crisis). In irradiated primary culture fibroblasts, the expression of the delayed chromosomal instability lasts for several cell divisions without inducing cell death. Several rounds of fusions- breakage-fusions can be performed and unbalanced clones emerge (gain or loss of chromosomes with the shorter telomeres would become unstable first.. The difference in the chromosomal instability among donors could be due to a polymorphism in telomere lengths. This could induce large variation in long term response to irradiation among individuals. (author)

  7. Automatic aberration scoring using whole chromosome F.I.S.H

    International Nuclear Information System (INIS)

    A radiation-induced rearrangement involving a painted and a non-painted chromosome will usually result in two partly-painted chromosomes, typically either a dicentric chromosome and associated fragment, or a reciprocal translocation pair. A consequence of such a rearrangement is that the number of painted image regions in the metaphase is increased by one, and their size distribution is altered. More complex rearrangements are uncommon, particularly at low doses. A high proportion of damaged cells can therefore be registered simply by detecting when the distribution of painted components differs from the expected number and size. A system has been constructed to pre-screen for damaged cells. It comprises automatic fluorescence metaphase finding followed by relocation and digitization of probe and counterstain channels at high resolution. Fully automatic segmentation in counterstain discriminates chromosomes from interphase nuclei and determines whether a metaphase is approximately diploid. The painted regions are segmented and their relative sizes estimated. Rules are applied which reduce the false positives due to artifacts such as overlapped painted chromosomes. More than 70% of cells with radiation damage involving painted and unpainted chromosomes were detected in a preliminary experiment using a small data set, with a low false positive rate. Results from a larger experiment in progress are presented

  8. In Vitro genotoxic and antigenotoxic studies of Thai Noni fruit juice by chromosomal aberration and sister chromatid exchange assays in human lymphocytes

    Directory of Open Access Journals (Sweden)

    Treetip Ratanavalachai

    2008-09-01

    Full Text Available The genotoxic and antigenotoxic effects of Noni fruit juice produced in Thailand have been studied in human lymphocytes for chromosome aberration assay and sister chromatid exchange (SCE assay in vitro. Treatment of Noni fruit juice(3.1-50 mg/ml alone for 3 h did not significantly induce chromosomal aberration or SCE (p<0.05. Noni fruit juice at 6.2 mg/ml is the optimum dose for cell survival and cell replication as demonstrated by the highest value of mitotic index and proliferation index (P.I.. Interestingly, pretreatment of Noni fruit juice at the same concentration of 6.2 mg/ml for 2 hfollowed by mitomycin C treatment at 3 μg/ml for 2 h significantly reduced SCE level induced by mitomycin C (p<0.05. However, these treatments did not show significant decrease in chromatid-type aberrations. Our data indicate that Thai Noni fruit juice is not genotoxic against human lymphocytes in vitro. In addition, pretreatment of Noni fruit juice at 6.2 mg/ml demonstrated no anticlastogenic effect while had some antigenotoxic effects as demonstrated by significant decrease in the SCE level induced by mitomycin C (p<0.05. Therefore, the optimum dose of Noni fruit juice used as a traditional medicine is required and needs to be studied further for the benefit of human health.

  9. Searching PubMed for molecular epidemiology studies: the case of chromosome aberrations

    DEFF Research Database (Denmark)

    Ugolini, Donatella; Neri, Monica; Knudsen, Lisbeth E;

    2006-01-01

    , 1980 to November 30, 2004. Only 2 of the 178 articles were indexed by the MeSH term "Epidemiology, molecular" (introduced in 1994) and 30 of 178 by the MeSH term "Biological markers" (introduced in 1989). The case of chromosome aberration (CA) was emblematic of the problem: 44 of 78 articles (56.......4%) were not pertinent to the search. The reasons for this poor performance are reported and discussed. Authors and indexers may be able to improve the efficiency of article retrieval in the field of molecular epidemiology by using relevant terms in the title and abstract. This may suggest appropriate Me......The available tools for searching literature in the field of Molecular Epidemiology are largely unsatisfactory. To identify major problems in retrieving information on this discipline, we comment here on the results of a literature search on cytogenetic biomarkers in children exposed to...

  10. Epidemiological study using the chromosome aberration technique in different population samples

    International Nuclear Information System (INIS)

    As far back as 10 years ago, the Gregorio Maranon General University Hospital (HGUGM) was equipped with a laboratory of biological dosimetry and has undertaken dosimetric estimations of individuals suspected with overexposure to ionizing radiation. For this purpose it was necessary to carry out studies on the basic frequency of chromosomal aberrations in a controlled (radiation exposed) population. A study was conducted on 72 individuals of the community of Madrid who had not been exposed to ionizing radiation. 500 metaphases per individual were examined and a basic frequency of 0.7 (dic)/1000 cells analysed. Parameters such as age, gender and cigarette consumption were considered and results show a linear dependency with age and consumption of cigarettes, but not with gender

  11. RBE of neutrons for induction of cell reproductive death and chromosome aberrations in three cell lines

    International Nuclear Information System (INIS)

    The authors have compared the RBE values for induction of dicentrics and centric rings with those for cell inactivation and with the mean or effective quality factors (Q) recommended for radiation protection. The induction of cell reproductive death and chromosome aberrations has been investigated in plateau phase cultures of established lines of a rat rhabdomyosarcoma, a rat ureter carcinoma and Chinese hamster cells for single doses of 300 kV X-rays and 0.5, 4.2 and 15 MeV neutrons. The different cell lines show considerable variations in sensitivity and the RBE values obtained are presented in tabular form. The mean RBE values for the rat rhabdomyosarcoma cells are lower than those for the other two relatively resistant cell lines. Those for the Chinese hamster cells extrapolated to levels according to low doses of X-rays are in good agreement with the quoted Q values. (Auth./C.F.)

  12. Calibration of chromosomal aberrations in the National Institute of Nuclear Research

    International Nuclear Information System (INIS)

    In the laboratory of biological dosimetry of the National Institute of Nuclear Research one carried out a calibration of chromosomal aberrations. The result obtained by the different participants does not mark to significant differences between the readings of the cells and the considered one of dose for each one of the cases. The biological material for this intercomparison was prepared in the Republic of Argentina like part of the activities of the Project Regional OIEA-RLA/9/054 Strengthening of the National Systems for the Preparation and Answer in Radiological and Nuclear Emergencies. In this regional project participates seven countries of the area and in October of this year will be presented the results of each one of them. Part of the objectives of this project is the one to conform a network of mutual aid in case of radiological accidents for which the participants must unify criteria. (Author)

  13. Comparative methylome analysis in solid tumors reveals aberrant methylation at chromosome 6p in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Altered patterns of DNA methylation are key features of cancer. Nasopharyngeal carcinoma (NPC) has the highest incidence in Southern China. Aberrant methylation at the promoter region of tumor suppressors is frequently reported in NPC; however, genome-wide methylation changes have not been comprehensively investigated. Therefore, we systematically analyzed methylome data in 25 primary NPC tumors and nontumor counterparts using a high-throughput approach with the Illumina HumanMethylation450 BeadChip. Comparatively, we examined the methylome data of 11 types of solid tumors collected by The Cancer Genome Atlas (TCGA). In NPC, the hypermethylation pattern was more dominant than hypomethylation and the majority of de novo methylated loci were within or close to CpG islands in tumors. The comparative methylome analysis reveals hypermethylation at chromosome 6p21.3 frequently occurred in NPC (false discovery rate; FDR=1.33 × 10−9), but was less obvious in other types of solid tumors except for prostate and Epstein–Barr virus (EBV)-positive gastric cancer (FDR<10−3). Bisulfite pyrosequencing results further confirmed the aberrant methylation at 6p in an additional patient cohort. Evident enrichment of the repressive mark H3K27me3 and active mark H3K4me3 derived from human embryonic stem cells were found at these regions, indicating both DNA methylation and histone modification function together, leading to epigenetic deregulation in NPC. Our study highlights the importance of epigenetic deregulation in NPC. Polycomb Complex 2 (PRC2), responsible for H3K27 trimethylation, is a promising therapeutic target. A key genomic region on 6p with aberrant methylation was identified. This region contains several important genes having potential use as biomarkers for NPC detection

  14. Chromatin dynamics during cell cycle mediate conversion of DNA damage into chromatid breaks and affect formation of chromosomal aberrations: Biological and clinical significance

    Energy Technology Data Exchange (ETDEWEB)

    Terzoudi, Georgia I.; Hatzi, Vasiliki I. [Institute of Radioisotopes and Radiodiagnostic Products, National Centre for Scientific Research ' Demokritos' , 15310 Ag. Paraskevi Attikis, Athens (Greece); Donta-Bakoyianni, Catherine [Oral Diagnosis and Radiology, University of Athens Dental School, Athens (Greece); Pantelias, Gabriel E., E-mail: gabriel@ipta.demokritos.gr [Institute of Radioisotopes and Radiodiagnostic Products, National Centre for Scientific Research ' Demokritos' , 15310 Ag. Paraskevi Attikis, Athens (Greece)

    2011-06-03

    The formation of diverse chromosomal aberrations following irradiation and the variability in radiosensitivity at different cell-cycle stages remain a long standing controversy, probably because most of the studies have focused on elucidating the enzymatic mechanisms involved using simple DNA substrates. Yet, recognition, processing and repair of DNA damage occur within the nucleoprotein complex of chromatin which is dynamic in nature, capable of rapid unfolding, disassembling, assembling and refolding. The present work reviews experimental work designed to investigate the impact of chromatin dynamics and chromosome conformation changes during cell-cycle in the formation of chromosomal aberrations. Using conventional cytogenetics and premature chromosome condensation to visualize interphase chromatin, the data presented support the hypothesis that chromatin dynamic changes during cell-cycle are important determinants in the conversion of sub-microscopic DNA lesions into chromatid breaks. Consequently, the type and yield of radiation-induced chromosomal aberrations at a given cell-cycle-stage depends on the combined effect of DNA repair processes and chromatin dynamics, which is cell-cycle-regulated and subject to up- or down-regulation following radiation exposure or genetic alterations. This new hypothesis is used to explain the variability in radiosensitivity observed at various cell-cycle-stages, among mutant cells and cells of different origin, or among different individuals, and to revisit unresolved issues and unanswered questions. In addition, it is used to better understand hypersensitivity of AT cells and to provide an improved predictive G2-assay for evaluating radiosensitivity at individual level. Finally, experimental data at single cell level obtained using hybrid cells suggest that the proposed hypothesis applies only to the irradiated component of the hybrid.

  15. Chromosomal aberrations and oxidative DNA adduct 8-hydroxy-2-deoxyguanosine as biomarkers of radiotoxicity in radiation workers

    Directory of Open Access Journals (Sweden)

    Sanaa A. El-Benhawy

    2016-07-01

    Conclusions: Scoring of chromosome aberrations such as breaks, fragments and dicentrics is a reliable method to detect previous exposure to ionizing radiation. This type of monitoring may be used as a biological dosimeter instead of physical dosimetry.8-OHdG is a useful oxidative DNA marker among radiation workers and those exposed to environmental carcinogens.

  16. Subwavelength-grating-induced wavefront aberrations: a case study

    Science.gov (United States)

    Crabtree, Karlton; Chipman, Russell A.

    2007-07-01

    The on-axis wavefront aberrations of a one-dimensional subwavelength-grating antireflection coating on an f/1.7 lens surface are shown to be small with noticeable contributions of defocus, astigmatism, and piston. The astigmatism is 0.02 wave, and the magnitude of the piston approaches one wave peak-to-valley. The difference in aberrations between orthogonally polarized wavefronts, or the retardance aberration, shows 0.01 wave of astigmatismlike variation and more than 0.01 wave of retardance-induced defocuslike variation. A small coupling between polarization states occurs in the form of the familiar Maltese cross, yielding a maximum of 3% coupling in the four diagonal edges of the pupil.

  17. How reliable are chromosomal aberration assays as bio markers of individual towards ionising radiation?

    International Nuclear Information System (INIS)

    Full text: Biomarkers of susceptibility or sensitivity towards ionising radiation can be important for the identification of individuals that may be at increased risk for the development of cancer after occupational, environmental or medical exposures. It is essential that these biomarkers have certain traits in order to be effective indicators of sensitivity. They should be specific, sensitive and reliable. Possible candidates for biomarkers of radiosensitivity are chromosomal aberrations. It has been shown that the induction of chromatid aberrations after irradiation of lymphocytes in G2 phase of the cell cycle and the induction of MN after irradiation in Go both allow discrimination between normal individuals and patients with cancer prone genetic diseases. In this study we investigated the inter- and intra- individual variation of the MN assay and the G2 assay in irradiated lymphocytes to assess their suitability as biomarkers of susceptibility. For this, the G2 assay and the MN assay were performed on blood samples of 10 healthy individuals. For the MN assay Go lymphocytes were exposed to 3.5 Gy Co γ-rays either at high dose-rate (HDR) and stimulated immediately or with 6h delay (DS) or at low dose-rate (LDR). For the G2 assay lymphocytes were irradiated with a dose of 0.4 Gy Co γ-rays in G2 phase of the cell cycle. Two individuals were assayed 9 times each in nine different experiments over a time period of 1 year. All samples were analysed by 2 scorers and no significant differences between them were observed using a paired t-test. The repeat experiments on blood samples of the same donor revealed that the inter-experimental/intra-individual coefficients of variation were not significantly different from the inter-individual coefficients of variation in both G2 and MN assay. As the intra-individual variability determines the assay reproducibility this would indicate that the assays are not able to detect real, reproducible differences in radiation

  18. Origin of clonal chromosome aberrations observed in A-bomb survivors

    International Nuclear Information System (INIS)

    The purpose of the present study was to elucidate whether abnormal clone cells possessing chromosome aberrations observed in A-bomb survivors were derived from stem cells or peripheral lymphocytes. Subjects were 12 survivors in Hiroshima who were known to have abnormal clone cells in 3 - 12% peripheral lymphocyte count. Lymphocytes were isolated by Ficoll conray method, labeled by mouse monoclonal antibody against human CD45RA or CD45RO and then by the secondary antibody beads against mouse IgG. The respective cells were further divided to cells with (+) or without (-) magnetic label by magnetic cell separation method. Naive T cells were CD45RA+ and CD45RO- and memory T cells, - and +, respectively. Clonal chromosome abberations were analyzed by multiple FISH staining with DNA probes for biotin-FITC, Cy3, WCPOrange and FITC-labeled centromere. It was found that in 12 subjects 8 lymphocyte cases were stem cell origin and 5 cases, peripheral lymphocyte. The mean frequency of the former was found to be 7.6% in total lymphocyte count and the latter, 3.6%, indicating that the difference of origin was the cause of the difference of the frequency. Clonal cell growth can be related with re-arrangement of DNA by tumor- or tumor suppressor-gene.(K.H.)

  19. Chromosome abnormalities in colorectal adenomas: two cytogenetic subgroups characterized by deletion of 1p and numerical aberrations

    DEFF Research Database (Denmark)

    Bomme, L; Bardi, G; Pandis, N;

    1996-01-01

    Cytogenetic analysis of short-term cultures from 34 benign colorectal polyps, all histologically verified as adenomas, revealed clonal chromosome aberrations in 21 of them. Eight polyps had structural rearrangements, whereas only numerical changes were found in 13. A combination of structural and...... changes were +20, +13, and monosomy 18, found in six, five, and two adenomas, respectively. Rearrangement of chromosome 1 was the most common structural change. Abnormalities involving 1p were seen in six adenomas, leading to visible loss of material in three. One adenoma had one clone with a large and...... another with a small 1p deletion. In three adenomas, del(1)(p36) was the only cytogenetic aberration, supporting the authors' previous conclusion that loss of one or more gene loci in band 1p36 is a common early change in colorectal tumorigenesis. Chromosome 8 was involved in structural changes in two...

  20. Delayed chromosomal instability induced by DNA damage.

    OpenAIRE

    Marder, B A; Morgan, W. F.

    1993-01-01

    DNA damage induced by ionizing radiation can result in gene mutation, gene amplification, chromosome rearrangements, cellular transformation, and cell death. Although many of these changes may be induced directly by the radiation, there is accumulating evidence for delayed genomic instability following X-ray exposure. We have investigated this phenomenon by studying delayed chromosomal instability in a hamster-human hybrid cell line by means of fluorescence in situ hybridization. We examined ...

  1. Chromosomal aberrations in benign and malignant Bilharzia-associated bladder lesions analyzed by comparative genomic hybridization

    International Nuclear Information System (INIS)

    Bilharzia-associated bladder cancer (BAC) is a major health problem in countries where urinary schistosomiasis is endemic. Characterization of the genetic alterations in this cancer might enhance our understanding of the pathogenic mechanisms of the disease but, in contrast to nonbilharzia bladder cancer, BAC has rarely been the object of such scrutiny. In the present study, we aimed to characterize chromosomal imbalances in benign and malignant post-bilharzial lesions, and to determine whether their unique etiology yields a distinct cytogenetic profile as compared to chemically induced bladder tumors. DNAs from 20 archival paraffin-embedded post-bilharzial bladder lesions (6 benign and 14 malignant) obtained from Sudanese patients (12 males and 8 females) with a history of urinary bilharziasis were investigated for chromosomal imbalances using comparative genomic hybridization (CGH). Subsequent FISH analysis with pericentromeric probes was performed on paraffin sections of the same cases to confirm the CGH results. Seven of the 20 lesions (6 carcinomas and one granuloma) showed chromosomal imbalances varying from 1 to 6 changes. The most common chromosomal imbalances detected were losses of 1p21-31, 8p21-pter, and 9p and gain of 19p material, seen in three cases each, including the benign lesion. Most of the detected imbalances have been repeatedly reported in non-bilharzial bladder carcinomas, suggesting that the cytogenetic profiles of chemical- and bilharzia-induced carcinomas are largely similar. However, loss of 9p seems to be more ubiquitous in BAC than in bladder cancer in industrialized countries

  2. The induction by X-rays of chromosome aberrations in male guinea-pigs, golden hamsters and rabbits

    International Nuclear Information System (INIS)

    Translocations induced by X-rays in post-meiotic germ cells of male guinea-pigs, golden hamsters and rabbits were studied cytologically in the F1 sons of the irradiated males. The percentage of spermatocytes displaying multivalent configurations varied with the translocation, but the average percentage appeared to depend on the species: fewer quadrivalents were observed in hamster than in guinea-pig heterozygotes and most were recorded for rabbit heterozygotes. Chain quadrivalents were more abundant than ring quadrivalents at meiosis for the guinea-pig and hamster in contrast to the mouse. Too few translocation heterozygotes were examined to determine which meiotic configuration was the more prevalent in the rabbit. In all three species, as in the mouse, translocations were found which caused male sterility, due to partial or complete failure of spermatogenesis, although most translocations caused semi-sterility. For these semi-sterile males both the frequency and time of embryonic death in the progeny appeared to be the same as in the mouse. It is concluded that similar types of chromosome aberrations are induced by X-rays in post-meiotic germ cells of male guinea-pigs, rabbits, golden hamsters and mice

  3. Gene expression changes and chromosomal aberrations in TK-6 cells after exposure to TK-6 clastogenic factors

    International Nuclear Information System (INIS)

    Full text: It is well accepted that cells in response to radiation exposure may release certain transmissible factors. These transmissible factors, clastogenic factors, have been reported to induce genomic instability in cells that have not been exposed to radiation. We hypothesize that this observed bystander effect might be a consequence of cellular interactions via secretary proteins such as cytokines released by the irradiated cells to affect the non-irradiated cells and initiate a systemic stress response to deal with the exposure. We will identify some of these stress response factors induced by ionizing radiation. TK-6 cells, a human lymphoblastoid cell line with a stable kariotype and a functional p53 protein, were chosen as the surrogate for determining the stress response activation. Non-irradiated TK-6 cells were co-cultured with irradiated and non-irradiated TK-6 or whole blood in trans-wells, where the cells were kept separate but the culture media was free to diffuse across the membrane. Cytokine microarray analysis 4 hours post co-culturing monitored the cytokine gene expression changes and the dicentric assay was used to evaluate chromosomal aberrations in TK-6 cells

  4. Analysis of chromosomal aberrations, micronuclei and hematological disorders among workers of wireless communication instruments and cell phone (Mobile) users

    International Nuclear Information System (INIS)

    This study was carried out to investigate the hazardous effect of electromagnetic radiation (EMR) such as chromosomal aberration, disturbed micronucleus formation and hematological disorders that may detected among workers of wireless communication instruments and mobile phone users. Seven individuals ( 3 males and 4 females) of a central workers in the microwave unit of the wireless station and 7 users of Mobil phone (4 males and 3 females ) were volunteered to give blood samples. Chromosomes and micronucleus were prepared for cytogenetic analysis as well as blood film for differential count. The results obtained in the microwave group indicated that, the total summation of all types of aberrations (chromosomes and chromatid aberrations) had a frequency of 6. 14% for the exposed group, whereas, the frequency in the control group amounted to 1.57%. In Mobil phone users, the total summation of all types of aberrations(chromosome and chromatid aberrations) had a frequency of 4.43% for the exposed group and 1.71% for the control group. The incidence of the total number of micronuclei in the exposed microwave group was increased 4.3 folds as compared with those of the control group The incidence of the total number of micronuclei in the exposed mobile phone group was increased 2 fold as compared with those in the control group. On the other hand, normal ranges of total white blood cells counts were determined for mobile phone users but abnormalities in the differential counts of the different types of the white blood cells such as neutropenia, eosinophilia and lymphocytosis were observed in the individuals number 1,2,3,7 in microwave group

  5. Effect of low-dose acute X-irradiation on the frequencies of chromosomal aberrations in human peripheral lymphocytes in vitro

    International Nuclear Information System (INIS)

    In a coordinated research programme sponsored by the International Atomic Energy Agency, the frequencies of chromosomal aberrations induced in peripheral blood lymphocytes (in vitro) by 250 kV X-rays at low doses (0.4, 1, 2, 3, 5, 10 and 30 rad) were determined. Blood from 2 donors was used to conduct one master experiment at these dose levels. The culture time used was 48 h and all samples including the controls were processed according to a standard protocol. The coded slides were scored by investigators from 10 participating laboratories. The main results are the following: the frequencies of all types of chromosome aberrations at 0.4 rad are significantly lower than the control values; there is no increase in the frequencies of dicentrics up to 2 rad and in those of terminal deletions up to 5 rad; the mean frequencies of all aberrations considered together are not significantly different from one another at 1, 2 and 3 rad (P=0.05); and (4) over the entire dose range the dose-effect relationship is clearly non-linear. (orig./AJ)

  6. Relative biological effectiveness of d(50)-Be neutrons determined for induction of chromosome aberrations in Allium cepa onion roots

    International Nuclear Information System (INIS)

    Relative biological effectiveness (RBE) of d(50)-Be neutrons, as a function of absorbed dose, was determined using as biological criterion induction of chromosome aberrations in Allium cepa onion roots. Two endpoints were used: mean number of aberrations per cell and percentage of intact cells, in anaphase and telophase. For both endpoints, RBE increases regularly from 7 to 12 when neutron absorbed dose decreases from 0.4 to 0.1 Gy. On the other hand, RBE/absorbed dose relationships are almost straight lines, in logarithmic coordinates, with a slope close to -1/2

  7. Effect of gamma irradiation on sex chromatin body appearance and the sex chromosome aberrations in the potato tuber moth, phthorimaea operculella (Lepidoptera: Gelechiidae)

    International Nuclear Information System (INIS)

    Genetic sexing technique based on the construction of a Balanced Lethal Strain (BLS) has been proposed for Phthorimaea operculella (Zeller). The isolation of female with T(W. Z) translocation is a fundamental step to develop such strain. Gamma irradiation was used to induce the requested translocations. The availability of sex-linked morphological marker is required to facilitate the detection of such mutations. Since a visible sex-linked marker has not been found in P. operculella, therefore main aim of our study was to determine the possibility of using sex heterochromatin body as a marker to identify the required translocated females. The appearance of sex heterochromatin body and the analysis of sex chromosomes in F1 females of irradiated P. operculella females were investigated. The percentage of abnormality in sex heterochromatin body in highly polyploid Malpighian tubule nuclei was increased by increasing the applied dose. Based on the appearance of this body, 3 mutant lines were isolated: elongated, small, fragmented lines. W chromosome was easily distinguished from Z chromosome when the analysis of pachytene sex chromosome bivalents of P. operculella females was carried out. The aberrations involved W chromosome directly influenced the appearance of sex heterochromatin body in highly polyploid somatic cells of the isolated mutant lines. The results showed that sex heterochromatin could be used as sex determination and cytogenetic marker in P. operculella. (Author)

  8. Study on the dose-response relation of premature chromosome condensation induced by Okadaic acid

    International Nuclear Information System (INIS)

    In order to study the effect-dosage relationship between the PCC induced by Okadaic acid and the IR dosages, human peripheral blood in vitro was irradiated by X-rays at different doses (0, 0.5, 1.0, 2.0, 3.0, 5.0Gy) cultivated for 48 hours and added with Okadaic acid two hours before the end of culture. Chromosome aberrations frequencies was analyzed and compared with that induced by the conventional chromosome assay and their dose-response curves were fitted. The results show that the mitotic index of the PCC induced by Okadaic acid is higher than that of the conventional chromosome assay. And the fragment rate of chromosome condensation induced by Okadaic acid has a favorable linearity relationship with external radiation doses. (authors)

  9. Chromosome aberrations produced by radiation: The relationship between excess acentric fragments and dicentrics

    International Nuclear Information System (INIS)

    Most chromosome aberrations produced by ionizing radiation develop from DNA double-strand breaks (DSBs). Published date on the yield and variance of excess acentric fragments after in vitro irradiation of human lymphocytes were compared with corresponding data on dicentrics. At low LET the number of excess acentric fragments is about 60% of the number of dicentrics, independent of dose and perhaps of dose rate, suggesting that dicentrics and excess acentric fragments arise from similar kinetics rather than from fundamentally different reactions. Only a weak dependence of the ratio on LET is observed. These results are quantified using generalizations of models for pairwise DSB interactions suggested by Brewen and Brock based on data for marsupial cells. By allowing singly incomplete and some open-quotes doubly incompleteclose quotes exchanges, the models can also account for the experimental observation that the dispersion for excess acentric fragments, a measure of cell-to-cell variance, is systematically larger than the dispersion for dicentrics. Numerical estimates of an incompleteness parameter are derived. 47 refs., 8 figs., 4 tabs

  10. Sensitivity of Bidens laevis L. to mutagenic compounds. Use of chromosomal aberrations as biomarkers of genotoxicity

    International Nuclear Information System (INIS)

    The wetland macrophyte Bidens laevis possesses suitable cytological characteristics for genotoxicity testing. To test its sensitivity as compared to terrestrial plants species currently in use in standardized assays, Methyl Methanesulfonate (MMS), N-ethyl-N-nitrosourea (ENU) and Maleic Hydrazide (HM) were used. On the other hand, the insecticide Endosulfan (ES) - an environmentally relevant contaminant - was assayed in seeds and two-month old plants. Mitotic Index (MI), frequency of Chromosome Aberrations in Anaphase-Telophase (CAAT) and frequency of Abnormal Metaphases (AM) were analyzed. MH, MMS and ENU caused a significant decrease of the MI. MMS was aneugenic whereas MH and ENU were both aneugenic and clastogenic. ES caused a significant concentration-dependent increase of total- and aneugenic-CAAT in roots and a significant high frequency of AM at high concentrations. Because of its sensitivity to mutagenic substances, B. laevis can be regarded as a reliable and convenient species for genotoxicity assays especially if aquatic contaminants are evaluated. - The wetland macrophyte Bidens laevis is sensitive to genotoxic compounds similarly to terrestrial standardized species.

  11. Sensitivity of Bidens laevis L. to mutagenic compounds. Use of chromosomal aberrations as biomarkers of genotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Perez, D.J. [Laboratorio de Genetica, Estacion Experimental Agropecuaria Balcarce (INTA), Facultad de Ciencias Agrarias, UNMdP, CC 276, 7620 Balcarce (Argentina); Laboratorio de Ecotoxicologia, Departamento de Ciencias Marinas, Facultad de Ciencias Exactas y Naturales, UNMdP, Funes 3350, 7600 Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Rivadavia 1917, 1033 Buenos Aires (Argentina); Lukaszewicz, G. [Laboratorio de Ecotoxicologia, Departamento de Ciencias Marinas, Facultad de Ciencias Exactas y Naturales, UNMdP, Funes 3350, 7600 Mar del Plata (Argentina); Menone, M.L., E-mail: lujanm@mdp.edu.a [Laboratorio de Ecotoxicologia, Departamento de Ciencias Marinas, Facultad de Ciencias Exactas y Naturales, UNMdP, Funes 3350, 7600 Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Rivadavia 1917, 1033 Buenos Aires (Argentina); Camadro, E.L. [Laboratorio de Genetica, Estacion Experimental Agropecuaria Balcarce (INTA), Facultad de Ciencias Agrarias, UNMdP, CC 276, 7620 Balcarce (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Rivadavia 1917, 1033 Buenos Aires (Argentina)

    2011-01-15

    The wetland macrophyte Bidens laevis possesses suitable cytological characteristics for genotoxicity testing. To test its sensitivity as compared to terrestrial plants species currently in use in standardized assays, Methyl Methanesulfonate (MMS), N-ethyl-N-nitrosourea (ENU) and Maleic Hydrazide (HM) were used. On the other hand, the insecticide Endosulfan (ES) - an environmentally relevant contaminant - was assayed in seeds and two-month old plants. Mitotic Index (MI), frequency of Chromosome Aberrations in Anaphase-Telophase (CAAT) and frequency of Abnormal Metaphases (AM) were analyzed. MH, MMS and ENU caused a significant decrease of the MI. MMS was aneugenic whereas MH and ENU were both aneugenic and clastogenic. ES caused a significant concentration-dependent increase of total- and aneugenic-CAAT in roots and a significant high frequency of AM at high concentrations. Because of its sensitivity to mutagenic substances, B. laevis can be regarded as a reliable and convenient species for genotoxicity assays especially if aquatic contaminants are evaluated. - The wetland macrophyte Bidens laevis is sensitive to genotoxic compounds similarly to terrestrial standardized species.

  12. Chromosome aberrations as a means to determine occupational exposure: an alternative

    International Nuclear Information System (INIS)

    The methodology developed to study chromosome aberrations in vitro, and the results gained in application of the method in in vivo studies of individuals receiving ionizing radiation, may provide a basis to more definitively assess occupational exposure in radiographers and radiation therapy technologists. The need for more definitive methods in measuring occupational exposure is given impetus by the fact that there is now a large group of individuals in whom a significant duration of occupational exposure may be measured. Further, increased knowledge of the effects of radiation has resulted in lower and lower levels of maximum permissible dose. And there is the undeniable, albeit relatively unproven, claim of radiation hazard in occupations not previously considered. As a group, technologists are now better organized and more aware of occupational hazards than in the past. It behooves us as professionals to act in our own behalf to improve the state of knowledge and methods of evaluation of occupational hazards that we have endured for several decades. There is no longer any more time to waste in the light of what we now know. In the author's opinion, the method described herein has the potential to determine occupational dose more accurately and definitively than has been possible heretofore and, therefore, should be tested as an alternative to present methods of personnel monitoring. History, rationale, and method are presented, and a protocol for a research study is described

  13. Relationship of enhanced survival during confluent holding recovery in ultraviolet-irradiated human and mouse cells to chromosome aberrations, sister chromatid exchanges, and DNA repair

    International Nuclear Information System (INIS)

    The relationship among cellular recovery from ultraviolet light (UVL) damage, cytogenetic changes, and DNA repair was studied in density-inhibited cultures of mouse 10T1/2 cells and human diploid fibroblasts. Both cell types showed similar UVL sensitivites to cell killing and a similar enhancement in survival when subculture to a low density was delayed for 24-48 hr after irradiation (potential lethal damage repair). However, excision repair as measured by the loss of endonuclease-sensitive sites was biphasic and much slower in the mouse cells: 30% were removed in the first 24 hr compared with 60% removed in the first 5 hr in the human cells. More than five times as many excision-induced DNA strand breaks as measured by alkaline elution were detected in the human as compared with the mouse cells. DNA-protein crosslinks were removed with a T 1/2 of 30 hr after 10 J/m2 UVL. UVL induced few chromosomal aberrations in the human cells as compared with mouse cells. The frequency of induced sister chromatid exchanges and the pattern of their decline during recovery were similar in both cell types; the kinetics of this decline was similar to that observed for the removal of DNA-protein crosslinks, and slowly removed endonuclease-sensitive sites. Chromosome aberrations, however, correlated with rapidly removed endo sites and DNA strand breaks and appeared to reflect the number of residual pyrimidine dimers in DNA at the time of its replication

  14. Effect of vitamin E on cytotoxicity, DNA single strand breaks, chromosomal aberrations, and mutation in Chinese hamster V-79 cells exposed to ultraviolet-B light

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, M.; Tsuzuki, K.; Matsumoto, K.; Ogura, R. (Kurume Univ., Fukuoka (Japan). School of Medicine)

    1992-07-01

    The effect of pretreatment with vitamin E on cytotoxicity, DNA single strand breaks, and chromosomal aberrations as well as on mutation induced by ultraviolet-B light (UV-B) was investigated in Chinese hamster V-79 cells. Cellular pretreatment with non-toxic levels of 25 {mu}M {alpha}-tocopherol succinate (vitamin E) for 24h prior to exposure resulted in a 10-fold increase in cellular levels of {alpha}-tocopherol. Using a colony-forming assay, this pretreatment decreased the cytotoxicity of UV-B light. However, alkaline elution assays demonstrated that pretreatment with vitamin E did not affect the number of DNA single strand breaks caused by UV-B light. UV-B exposure produced a dose-dependent induction of chromosomal aberrations and mutations at the HGPRT locus, and neither of these actions of UV-B was influenced by pretreatment with the vitamin. These results suggest that vitamin E protects cells from UV-B-induced cytotoxicity, possibly through its ability to scavenge free radicals. The genotoxicity induced by UV-B light may not correlate directly with the cytotoxic action of this wavelength region in sunlight. (author).

  15. Effect of vitamin E on cytotoxicity, DNA single strand breaks, chromosomal aberrations, and mutation in Chinese hamster V-79 cells exposed to ultraviolet-B light

    International Nuclear Information System (INIS)

    The effect of pretreatment with vitamin E on cytotoxicity, DNA single strand breaks, and chromosomal aberrations as well as on mutation induced by ultraviolet-B light (UV-B) was investigated in Chinese hamster V-79 cells. Cellular pretreatment with non-toxic levels of 25 μM α-tocopherol succinate (vitamin E) for 24h prior to exposure resulted in a 10-fold increase in cellular levels of α-tocopherol. Using a colony-forming assay, this pretreatment decreased the cytotoxicity of UV-B light. However, alkaline elution assays demonstrated that pretreatment with vitamin E did not affect the number of DNA single strand breaks caused by UV-B light. UV-B exposure produced a dose-dependent induction of chromosomal aberrations and mutations at the HGPRT locus, and neither of these actions of UV-B was influenced by pretreatment with the vitamin. These results suggest that vitamin E protects cells from UV-B-induced cytotoxicity, possibly through its ability to scavenge free radicals. The genotoxicity induced by UV-B light may not correlate directly with the cytotoxic action of this wavelength region in sunlight. (author)

  16. CHROMOSOMAL ABERRATIONS AND MICRONUCLEI IN LYMPHOCYTES OF MEDICAL RADIATION WORKERS EXPOSED TO LONIZING RADIATION BELOW DOSE LIMIT

    Directory of Open Access Journals (Sweden)

    MOZDARANI H

    2001-01-01

    Full Text Available Introduction: Ionizing radiation induces various kinds of DNA damage in which may lead to chromosomal aberrations (CA. Inspite of growing importance in the risk assessment, the dose yield kinetics of CA and their implications for dose assessment are not well established in exposures to low level radiation. In the present study, cytochalasin-B blocked micronucleus assay and metaphase analysis were used as test system to monitor hospital radiation workers who received chronic low dose ionizing radiation below dose limit. Materials and Methods: Heparinized blood samples were taken from healthy non-smoker radiology and radiotherapy workers occupationally exposed to X and gamma rays and healty population whose duties do not expose them to radiation sources and chemical agents. The whole body dose was measured by film badge. Lymphocytes were cultured in RPMI-1640 supplemented with 15% FBS, and metaphase spread was prepared using standard cytogenetic method. Cytochalasine-B (3 mg/mltreatment was used for binuclei micronuclei assay. 100 mitoses and 1000 binuclei lymphocytes were scored for CA and micronuclei (MN respectively. Results: Results show a high frequency of CA mainly deletions and simple breaks in radiation workers compared to control (p<0.001. Also results show the mean MN/cell was significantly (p<0.001 higher in radiation workers(0.035 when compared to non exposed individuals(0.022. Conclusion: A relatively high frequency of MN and CA formation in lymphocytes of radiation workers compared to non exposed individuals might be due to an accumulation of initial DNA damage in people exposed to chronic doses of radiation leading to detectable genetic damages. These observations might imply that the current occupational exposure levels might be inadequate to prevent an increase in chromosome damage rate.

  17. Dose Response for Chromosome Aberrations in Human Lymphocytes and Fibroblasts after Exposure to Very Low Doses of High LET Radiation

    Science.gov (United States)

    Hada, M.; George, Kerry; Cucinotta, Francis A.

    2011-01-01

    The relationship between biological effects and low doses of absorbed radiation is still uncertain, especially for high LET radiation exposure. Estimates of risks from low-dose and low-dose-rates are often extrapolated using data from Japanese atomic bomb survivors with either linear or linear quadratic models of fit. In this study, chromosome aberrations were measured in human peripheral blood lymphocytes and normal skin fibroblasts cells after exposure to very low dose (1-20 cGy) of 170 MeV/u Si-28- ions or 600 MeV/u Fe-56-ions. Chromosomes were analyzed using the whole chromosome fluorescence in situ hybridization (FISH) technique during the first cell division after irradiation, and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving greater than 2 breaks in 2 or more chromosomes). The curves for doses above 10 cGy were fitted with linear or linear-quadratic functions. For Si-28- ions no dose response was observed in the 2-10 cGy dose range, suggesting a non-target effect in this range.

  18. Application of the Alkaline Comet Assay and the Analysis of Structural Chromosome Aberrations in Assessment of Genetic Damage After Accidental Exposure to Ionising Radiation

    International Nuclear Information System (INIS)

    Full text: Living with the effects of low-level ionising radiation is one of the normal hazards of life. However, the effects of lower doses may not show up for years after exposure and are due to various changes in DNA molecules and chromosomes. Radiation-induced mutations seem to be brought about by the deletion of small pieces of chromosomes during the process of chromosome breakage and repair. Since chromosome damage is most likely to happen in dividing cells, ionising radiation usually cause cancer in those parts of the body where cells are actively dividing. Ionising radiation kills rapidly dividing cells, blood lymphocytes among them. People are exposed to high doses of ionising radiation when radiation accidents occur. The cytogenetical consequences of accidental exposure to gamma-radiation (radiation dose 221 mSv) were investigated by using alkaline Comet assay and the analysis of structural chromosomal aberrations (CA). Blood samples were repeatedly collected during one-year period after the accident. By using the Comet assay immediately after accidental exposure a high level of DNA damage was recorded. Although this level was decreasing over a one-year period, it was still elevated compared to normal values of DNA damage for unexposed persons. Immediately after the accident prevalence of CA (dicentrics, acentrics) over chromatid aberrations was recorded. However, one year afterwards only a few chromatid breaks were recorded. Our results confirmed usefulness of the alkaline Comet assay as a simple and sensitive technique for the biomonitoring of DNA damages, especially in the cases of accidental exposure to ionising radiation. (author)

  19. Impact of personal and environmental factors on the rate of chromosome aberrations named translocations - Part 1: age, gender, smoking, alcohol

    International Nuclear Information System (INIS)

    The assessment of exposure to ionizing radiation, carried out long time after exposure, is currently performed by scoring of translocations, a specific type of chromosomal aberrations. The translocations rate observed in peripheral blood lymphocytes of exposed subjects is compared to that observed in a control population. However, the translocation specificity towards radiation exposure is not clearly identified. To avoid any hasty conclusion, it is necessary to identify all the factors likely to induce translocation. To our knowledge, no study has thus far examined the effects of all these different factors on translocation rates. A review of the literature thus allowed us to assess the impact of host factors and lifestyle on the production of translocations. This study confirms that age appears to be the factor having the greatest impact on the rate of translocations, especially over 60 years. To date, the factor 'age' is already considered in estimating the impact of radiation on the rate of translocation for all age groups. However, the study also shows that this rate varies significantly when the patient is exposed simultaneously and significantly towards many lifestyle agents. A precise threshold translocation rate should thus be established as a function of known behavioral exposures, below which it is impossible to conclude that radiological exposure has occurred. The effects of chemicals on the translocation rate after occupational exposure will be the subject of a second part. (authors)

  20. The effects of biological and life-style factors on baseline frequencies of chromosome aberrations in human lymphocytes

    Directory of Open Access Journals (Sweden)

    Hilada Nefic

    2014-01-01

    Full Text Available Objective: This study investigated the influence of sex and ageing on chromosomal damage and the role of life-style habits on the frequency of chromosomal aberrations (CAs in peripheral blood lymphocytes (PBLs of healthy Bosnian subjects. Materials and Methods: Peripheral blood samples were obtained from 100 healthy, unrelated individuals in Bosnia and Herzegovina during 2010 and 2011. Chromosome preparations were made by dropping and air drying and slides were stained with 10% Giemsa solution (pH 6.8. The cytogenetic analysis was carried out in a cytogenetic laboratory in the Department of Biology of the Faculty of Science in Sarajevo. The category of total structural CAs was sub classified as chromosome-type aberrations (CSAs and chromatid-type aberrations (CTAs while the category of total numerical CAs was sub classified as aneuploid and polyploid mitoses. All statistical analyses were carried out using Microsoft Excel 2010 (Microsoft Corporation and the Windows Kwikstat Winks SDA 7.0.2 statistical software package (Texa Soft Cedar Hill, Texas. Results: Cytogenetic analysis revealed the average number of structural CAs was 2.84 and of numerical CAs was 9.56. There was a significant increase in the frequency of chromosome-type aberrations (1.92 compared with chromatid-type aberrations (CTAs (0.92 and a significant increase in the frequency of aneuploid (8.83 compared with polyploid (0.73 mitoses. Significant positive correlations between age and CTAs in human PBLs were also demonstrated. Additional statistical analysis showed that ageing increase number of numerical CAs in lymphocytes of drinkers. The frequency of structural CAs of females exposed to radiation was significantly greater than in males. Analysis indicates the presence of a positive association between CAs and smoking in younger subjects but a negative correlation between aberrant cells frequencies and alcohol in older drinkers. Conclusion: The results of the study support the

  1. The frequency of chromosomal aberrations in sheep from the area contaminated by depleted uranium during NATO air strikes in 1999

    OpenAIRE

    Fišter Svetlana L.; Jović Slavoljub Z.

    2014-01-01

    This paper presents the results of cytogenetic studies in sheep from the region of Bujanovac that was contaminated by depleted uranium during the NATO air strikes in 1999. The study was conducted on sheep blood lymphocytes, in order to determine the frequency of chromosomal aberrations and to assess the presence of genetic risk as a result of the possible impact of depleted uranium. Blood samples for lymphocyte cultures were taken at random from the 20 anim...

  2. Influence of the shielding on the induction of chromosomal aberrations in human lymphocytes exposed to high-energy iron ions

    International Nuclear Information System (INIS)

    Computer code calculations based on biophysical models are commonly used to evaluate the effectiveness of shielding in reducing the biological damage caused by cosmic radiation in space flights. Biological measurements are urgently needed to benchmark the codes. We have measured the induction of chromosomal aberrations in human peripheral blood lymphocytes exposed in vitro to 56Fe-ion beams accelerated at the Heavy for Medical Accelerator in Chiba (HIMAC) synchrotron in Chiba. Isolated lymphocytes were exposed to the 500 MeV/n iron beam (dose range 0.1-1 Gy)after traversal of 0 to 8 g/cm2 of either polymethylmethacrylate (PMMA) (lucite, a common plastic material) or aluminum. Three PMMA shield thickness and one Al shield thickness were used. For comparison, cells were exposed to 200 MeV/n iron ions and to X-rays. Chromosomes were prematurely condensed by a phosphatase inhibitor (calyculin A) to avoid cell-cycle selection produced by the exposure to high-linear energy transfer (LET) heavy ion beams. Aberrations were scored in chromosomes 1, 2,and 4 following fluorescence in situ hybridization. The yield of chromosomal aberrations per unit dose at the sample position was poorly dependent on the shield thickness and material. However, the yield of aberrations per unit ion incident on the shield was increased by the shielding. This increase is associated to the increased dose-rate measured behind the shield as compared to the direct beam. These preliminary results prove that shielding can increase the effectiveness of heavy ions, and the damage is dependent upon shield thickness and material. (author)

  3. Effect of blood storage and nutrient medium on the yield of chromosome aberrations under subsequent X-irradiation

    International Nuclear Information System (INIS)

    Conducted are cytogenetic investigations on studing of chromosomal aberrations frequency depending on storage time (0, 24, 48, 72 h) of nonirradiated and X-irradiated blood and nutrient medium in glass and plastic vessels at the temperature of 20 deg C. It is established that it is not advisable to store blood in plastic vessels for biological dosimetry purposes. It is recommended to use either fresh blood or blood stored in vessels from neutral glass

  4. Genetic Alterations in Pesticide Exposed Bolivian Farmers: An evaluation by analysis of chromosomal aberrations and the comet assay

    Directory of Open Access Journals (Sweden)

    Erik Jørs

    2007-01-01

    Full Text Available Background: Pesticides are of concern in Bolivia because of increasing use. Frequent intoxications have been demonstrated due to use of very toxic pesticides, insufficient control of distribution and sale and little knowledge among farmers of protective measures and hygienic procedures.Method: Questionnaires were applied and blood tests taken from 81 volunteers from La Paz County, of whom 48 were pesticide exposed farmers and 33 non-exposed controls. Sixty males and 21 females participated with a mean age of 37.3 years (range 17–76. Data of exposure and possible genetic damage were collected and evaluated by well known statistical methods, controlling for relevant confounders. To measure genetic damage chromosomal aberrations and the comet assay analysis were performed.Results: Pesticide exposed farmers had a higher degree of genetic damage compared to the control group. The number of chromosomal aberrations increased with the intensity of pesticide exposure. Females had a lower number of chromosomal aberrations than males, and people living at altitudes above 2500 metres seemed to exhibit more DNA damage measured by the comet assay.Conclusions: Bolivian farmers showed signs of genotoxic damage, probably related to exposure to pesticides. Due to the potentially negative long term health effects of genetic damage on reproduction and the development of cancer, preventive measures are recommended. Effective control with imports and sales, banning of the most toxic pesticides, education and information are possible measures, which could help preventing the negative effects of pesticides on human health and the environment.

  5. Effects of 60Co γ-ray partial radiation on chromosome aberration in human peripheral blood in vitro

    International Nuclear Information System (INIS)

    Objective: To investigate the effects of 60Co γ-ray partial radiation on chromosome aberration in human peripheral blood in vitro. Methods: The samples of heparinized peripheral whole blood from 3 healthy persons were exposed to 60Co γ-rays at the doses between 0 and 8 Gy with the dose rate of 0.35 Gy/min at the temperature of 37 ℃ ,and then mixed with the unirradiated blood samples of the Microscopy was used to observe the chromosome aberration double (centromere + centromere) and the biological dose was estimated thereby. Results: The amounts of double centromere + centromere were increased along with the dose of irradiation in all groups. The estimated biological dose was higher than the 1/3 of the irradiation dose when the dose was between 0.5 to 2 Gy, and was close to the 1/3 of the irradiation dose when the dose was between 4 to 8 Gy. Conclusion: Chromosome aberration can be used as a biomarker in estimation of uneven irradiation. (authors)

  6. Dose assessment by quantification of chromosome aberrations and micronuclei in peripheral blood lymphocytes from patients exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva-Barbosa, Isvania; Pereira-MagnataI, Simey; Amaral, Ademir [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia - GERAR; Sotero, Graca [Fundacao de Hematologia e Hemoterapia, Recife, PE (Brazil); Melo, Homero Cavalcanti [Hospital do Cancer, Recife, PE (Brazil). Centro de Radioterapia de Pernambuco]. E-mail: isvania@uol.com.br

    2005-07-15

    Scoring of unstable chromosome aberrations (dicentrics, rings and fragments) and micronuclei in circulating lymphocytes are the most extensively studied biological means for estimating individual exposure to ionizing radiation (IR), which can be used as complementary methods to physical dosimetry or when the latter cannot be performed. In this work, the quantification of the frequencies of chromosome aberrations and micronuclei were carried out based on cytogenetic analyses of peripheral blood samples from 5 patients with cervical uterine cancer following radiotherapy in order to evaluate the absorbed dose as a result of partial-body exposure to 60Co source. Blood samples were collected from each patient in three phases of the treatment: before irradiation, 24 h after receiving 0.08 Gy and 1.8 Gy, respectively. The results presented in this report emphasize biological dosimetry, employing the quantification of chromosome aberrations and micronuclei in lymphocytes from peripheral blood, as an important methodology of dose assessment for either whole or partial-body exposure to IR.

  7. Induction of complete and incomplete chromosome aberrations by bleomycin in human lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Benkhaled, L.; Xuncla, M.; Caballin, M.R. [Universitat Autonoma de Barcelona, Unitat d' Antropologia Biologica, Departament de Biologia Animal, Biologia Vegetal i Ecologia, E-08193 Bellaterra (Spain); Barrios, L. [Universitat Autonoma de Barcelona, Unitat de Biologia Cel.lular, Departament de Biologia Cel.lular, Fisiologia i Immunologia (Spain); Barquinero, J.F. [Universitat Autonoma de Barcelona, Unitat d' Antropologia Biologica, Departament de Biologia Animal, Biologia Vegetal i Ecologia, E-08193 Bellaterra (Spain)], E-mail: Francesc.Barquinero@uab.es

    2008-01-01

    Bleomycin (BLM) is a clastogenic compound, which due to the overdispersion in the cell distribution of induced dicentrics has been compared to the effect of high-LET radiation. Recently, it has been described that in fibroblast derived cell lines BLM induces incomplete chromosome elements more efficiently than any type of ionizing radiation. The objective of the present study was to evaluate in human lymphocytes the induction of dicentrics and incomplete chromosome elements by BLM. Peripheral blood samples have been treated with different concentrations of BLM. Two cytogenetic techniques were applied, fluorescence plus Giemsa (FPG) and FISH using pan-centromeric and pan-telomeric probes. The observed frequency of dicentric equivalents increases linearly with the BLM concentration, and for all BLM concentrations the distribution of dicentric equivalents was overdispersed. In the FISH study the ratio between total incomplete elements and multicentrics was 0.27. The overdispersion in the dicentric cell distribution, and the linear BLM-concentration dependence of dicentrics can be compared to the effect of high-LET radiation, on the contrary the ratio of incomplete elements and multicentrics is similar to the one induced by low-LET radiation ({approx}0.40). The elevated proportion of interstitial deletions in relation to total acentric fragments, higher than any type of ionizing radiation could be a characteristic signature of the clastogenic effect of BLM.

  8. Induction of complete and incomplete chromosome aberrations by bleomycin in human lymphocytes

    International Nuclear Information System (INIS)

    Bleomycin (BLM) is a clastogenic compound, which due to the overdispersion in the cell distribution of induced dicentrics has been compared to the effect of high-LET radiation. Recently, it has been described that in fibroblast derived cell lines BLM induces incomplete chromosome elements more efficiently than any type of ionizing radiation. The objective of the present study was to evaluate in human lymphocytes the induction of dicentrics and incomplete chromosome elements by BLM. Peripheral blood samples have been treated with different concentrations of BLM. Two cytogenetic techniques were applied, fluorescence plus Giemsa (FPG) and FISH using pan-centromeric and pan-telomeric probes. The observed frequency of dicentric equivalents increases linearly with the BLM concentration, and for all BLM concentrations the distribution of dicentric equivalents was overdispersed. In the FISH study the ratio between total incomplete elements and multicentrics was 0.27. The overdispersion in the dicentric cell distribution, and the linear BLM-concentration dependence of dicentrics can be compared to the effect of high-LET radiation, on the contrary the ratio of incomplete elements and multicentrics is similar to the one induced by low-LET radiation (∼0.40). The elevated proportion of interstitial deletions in relation to total acentric fragments, higher than any type of ionizing radiation could be a characteristic signature of the clastogenic effect of BLM

  9. Relationship between chromosomal aberration of bone marrow cells and dosage of irradiation after 46Sc internal pollution and external low dose X-irradiation in mice

    International Nuclear Information System (INIS)

    The relationship between chromosomal aberration of bone marrow cells and dosage in mice 24 h after 46Sc internal pollution combined with external low dose whole body X-irradiation was quantiatively studied. The results showed that the relationship between chromosomal aberration and dosage was expressed in a linear regression equation. The chromosomal aberration rate was lower in the combined exposure than that of the sum of internal and external exposures, but higher than that of either the internal or external exposure singly. The relationship between chromosomal aberration and time was expressed in the following three phase exponential function: Y(t) = 2.9078 exp0.27668t + 2.9371 exp-0.0778t + 2.3786-0.01788t. By means of fit test, there was no significant difference between the determined and the theoretical values. The 90% theoretical values got from all the equations distributed over the determined values

  10. Radon exposure, chromosomal aberrations, and genetic polymorphisms in selected Slovak cave workers

    International Nuclear Information System (INIS)

    The aim of work was genotoxic risk assessment of the Slovak show cave workers employed by the Slovak Caves Administration in Liptovsky Mikulas. They are guides or administrators of the four Slovak show caves: Vazecka, Demanovska, Bystrianska, and Harmanecka. We examined 51 workers exposed to radon, with average age 35.64 years ± 6.63 (SD) and average exposition time 9.78 years ± 6.27 (SD). They are 43 men (i.e. 84.31 %) and 9 women (i.e. 15.69 %). The control group consisted of 32 healthy workers from Faculty Hospital in Martin. The workers were not exposed to any genotoxic agents. The average age is 31.84 years ± 5.84(SD). From every subject we evaluated 100 mitosis, i.e. 5100 mitosis from exposed workers and 3200 mitosis from control subjects. In exposed group we found in 111 cells chromosomal aberrations, this present 2.18 % Ab.c. ± 0.19 (SEM), and in control 1st group 1.53 % ± 0.16 (SEM). There are 106 breaks (95.50%), and 5 exchanges (4.50%) on chromosomes. The highest number of Ab.c. we detected in workers of Vazecka (2.63 % Ab.c) and Bystrianska (2.00 % Ab.c.) caves. There is a significant increase (P < 0.05) in the mean number of Ab.c. in workers of cave Vazecka as compared to control. In 15 cases (i.e. 28.30 %) we found increase or high exposure to genotoxic agents, we found any difference between sex, and any dependence of the number of Ab.c. on age and time of exposure. The Vazecka cave workers showed three times higher mean effective doses all the year round (milliSievert) than workers additional caves. The measured values of radiation in the caves and mines exceeded the permissible limits and Regional Hygienist of the Central Slovakia declared in 1981 the risk zones and, at the same time, the monitoring of working atmosphere was initiated. Our evaluations referred to certain exposition of this carcinogen in cave workers too. The essence of prevention is based in the lowering of ionizing radiation and improvement of the sanitary-technical component

  11. Determination of the relationship between genotypes and chromosomal aberration frequencies in a normal population

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, M.; Tucker, J. [Lawrence Livermore National Lab., CA (United States)

    1997-10-01

    Individual differences in cancer susceptibility may be attributed in part to genetic differences in the genes which code for enzymes involved in metabolic activation and detoxification of environmental procarcinogens. Polymorphisms of certain genes functioning in this manner (CYP2D6, CYP1A1, CYP2E1, NAT1, NAT2, GSTT1, GSTM1) have been linked to an increased risk of some cancers. An increased level of genomic instability, often reflected as an increase in chromosomal aberrations (CA), has also been associated with an elevated risk of cancer. Accurate polymorphism frequency determinations for these genes in a normal population is needed to establish whether these frequencies are different in a diseased population. In this work, analyses are being performed on over 100 normal individuals, ranging from 0 to 80 years of age, to determine CA frequency and genotypes. Individual exposure and health data have also been obtained from all individuals in the study. These analyses will provide a baseline frequency for the various gene polymorphisms in a normal (mainly Caucasian) population, and will determine whether a relationship between the CA frequency and certain polymorphisms and or genotypes exists. In addition the interaction between environmental exposures (such as smoking), genotypes and CA frequencies are being examined. At present 24 individuals have been genotyped for GSTT1, GSTM1 and CYP2D6(T) and their CA frequencies determined. Genotype frequencies of 21% for GSTM1 B, 4% for GSTM1 null, 29% for GSTM1 A, 21% for GSTM1 B, 4% for GSTM1 A,B, and 0% for CYP2D6(T) have been determined from the small sample analyzed to date. We plan to extend our genotype analysis to include the remaining CYP2D6 polymorphisms, CYP2E1, CYP1A1, NAT1 and NAT2.

  12. Chromosomal aberrations and aneuploidy in oral potentially malignant lesions: distinctive features for tongue

    Directory of Open Access Journals (Sweden)

    Castagnola Patrizio

    2011-10-01

    Full Text Available Abstract Background The mucosae of the oral cavity are different at the histological level but appear all equally exposed to common genotoxic agents. As a result of this exposure, changes in the mucosal epithelia may develop giving rise to Oral Potentially Malignant Lesions (OPMLs, which with time may in turn progress to Oral Squamous Cell Carcinomas (OSCCs. Therefore, much effort should be devoted to identify features able to predict the likeliness of progression associated with an OPML. Such features may be helpful in assisting the clinician to establish both appropriate therapies and follow-up schedules. Here, we report a pilot study that compared the occurrence of DNA aneuploidy and chromosomal copy number aberrations (CNAs in the OPMLs from different oral anatomical subsites. Methods Samples from histologically diagnosed OPMLs were processed for high resolution DNA flow cytometry (hr DNA-FCM in order to determine the relative DNA content expressed by the DNA index (DI. Additionally, array-Comparative Genomic Hybridization (a-CGH analysis was performed on DNA obtained from diploid nuclei suspensions directly. When aneuploid nuclei were detected, these were physically separated from diploid nuclei on the base of their DI values by means of a DNA-FCM-Sorter in order to improve the a-CGH analysis. Results Tongue OPMLs were more frequently associated with DNA aneuploidy and CNAs than OPMLs arising from all the other mucosal subsites. Conclusions We suggest that the follow-up and the management of the patients with tongue OPMLs should receive a distinctive special attention. Clearly, this hypothesis should be validated in a prospective clinical study.

  13. Effects of infliximab on sister chromatid exchanges and chromosomal aberration in patients with rheumatoid arthritis.

    Science.gov (United States)

    Atteritano, M; Mazzaferro, S; Mantuano, S; Bagnato, G L; Bagnato, G F

    2016-03-01

    The aim of this study was to evaluate in a 24-weeks the effect of anti-TNF-alpha, infliximab, on cytogenetic biomarkers in peripheral lymphocytes of patients with rheumatoid arthritis (RA). A total of 40 patients with RA met the criteria to be treated with methotrexate (15 mg/week) were evaluated. Twenty patients, randomly selected, were treated with infliximab in addition to methotrexate (group I), whereas the other 20 patients continued with only methotrexate treatment (group M). Twenty healthy volunteers matched for age, gender and smoking habits served as control group (group C). At baseline, sister chromatid exchange rate was 7.20 ± 2.21 in group I, 7.40 ± 1.60 in group M and 4.97 ± 1.32 in group C (P < 0.01 vs group I and M). After 24-weeks, sister chromatid exchange rate was 7.87 ± 2.54 in group I and 7.81 ± 1.95 in group M (P = ns). High frequency cells count was 4.9 % and 4.7 % in the groups I and M, respectively, at the end of the study (P = ns). The basal chromosomal aberration frequency was 4.90 % in group I and 5.20 % in groups M; after 24-weeks, this was 5.10 % in group I and 5.10 % in groups M (P = ns). Infliximab treatment, for 24 weeks, did not increase the cytogenetic biomarkers in patients with RA. Our data show that the use of infliximab has not a genotoxic effect in patients with RA. PMID:26012953

  14. Dose-dependence of the yield of chromosomal aberrations in human lymphocytes after irradiation of peripheral blood with monoenergetic neutrons of 2, 4 and 6 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sevan' kaev, A.V.; Obaturov, G.M.; Nasonova, V.A.; Izmajlova, N.N. (Akademiya Meditsinskikh Nauk SSSR, Obninsk. Nauchno-Issledovatel' skij Inst. Meditsinskoj Radiologii)

    A study was made of the dose-dependence of the yield of chromosome aberrations in human lymphocyte culture irradiated at the G/sub 0/ stage with monoenergetic neutrons of 2, 4 and 6 MeV. The dose dependence was found to be linear all types of aberrations. The RBE of neutrons under study increased with the decrease in their energy.

  15. 'BioQuaRT' project: design of a novel in situ protocol for the simultaneous visualisation of chromosomal aberrations and micronuclei after irradiation at microbeam facilities

    International Nuclear Information System (INIS)

    The aim of the 'BioQuaRT' (Biologically weighted Quantities in Radiotherapy) project is to develop measurement techniques for characterising charged particle track structure on different length scales, and to correlate at the cellular level the track structure properties with the biological effects of radiation. This multi-scale approach will allow characterisation of the radiation qualities used in radiotherapy and the related biological effects. Charged-particle microbeam facilities were chosen as the platforms for all radiobiology experiments in the 'BioQuaRT' project, because they allow targeting single cells (or compartments of a cell) with a predefined number of ionising particles and correlating the cell-by-cell induced damage with type and energy of the radiation and with the number of ions per cell. Within this project, a novel in situ protocol was developed for the analysis of the mis-repaired and/or unrepaired chromosome damage induced by charged-particle irradiations at the Physikalisch-Technische Bundesanstalt (PTB) ion microbeam facility. Among the cytogenetic biomarkers to detect and estimate radiation-induced DNA damage in radiobiology, chromosomal aberrations and micronuclei were chosen. The characteristics of the PTB irradiation system required the design of a special in situ assay: specific irradiation dishes with a base made from a bio-foil 25-μm thick and only 3000-4000 cells seeded and irradiated per dish. This method was developed on Chinese hamster ovary (CHO) cells, one of the most commonly used cell lines in radiobiology in vitro experiments. The present protocol allows the simultaneous scoring of chromosome aberrations and micronuclei on the same irradiated dish. Thanks to its versatility, this method could also be extended to other radiobiological applications besides the single-ion microbeam irradiations. (authors)

  16. 'BioQuaRT' project: design of a novel in situ protocol for the simultaneous visualisation of chromosomal aberrations and micronuclei after irradiation at microbeam facilities.

    Science.gov (United States)

    Patrono, C; Monteiro Gil, O; Giesen, U; Langner, F; Pinto, M; Rabus, H; Testa, A

    2015-09-01

    The aim of the 'BioQuaRT' (Biologically weighted Quantities in RadioTherapy) project is to develop measurement techniques for characterising charged particle track structure on different length scales, and to correlate at the cellular level the track structure properties with the biological effects of radiation. This multi-scale approach will allow characterisation of the radiation qualities used in radiotherapy and the related biological effects. Charged-particle microbeam facilities were chosen as the platforms for all radiobiology experiments in the 'BioQuaRT' project, because they allow targeting single cells (or compartments of a cell) with a predefined number of ionising particles and correlating the cell-by-cell induced damage with type and energy of the radiation and with the number of ions per cell. Within this project, a novel in situ protocol was developed for the analysis of the misrepaired and/or unrepaired chromosome damage induced by charged-particle irradiations at the Physikalisch-Technische Bundesanstalt (PTB) ion microbeam facility. Among the cytogenetic biomarkers to detect and estimate radiation-induced DNA damage in radiobiology, chromosomal aberrations and micronuclei were chosen. The characteristics of the PTB irradiation system required the design of a special in situ assay: specific irradiation dishes with a base made from a biofoil 25-µm thick and only 3000-4000 cells seeded and irradiated per dish. This method was developed on Chinese hamster ovary (CHO) cells, one of the most commonly used cell lines in radiobiology in vitro experiments. The present protocol allows the simultaneous scoring of chromosome aberrations and micronuclei on the same irradiated dish. Thanks to its versatility, this method could also be extended to other radiobiological applications besides the single-ion microbeam irradiations. PMID:25877532

  17. Concerning the evidence for the formation of dicentric chromosomal aberrations by single tracks of very short-ranged radiations

    International Nuclear Information System (INIS)

    A recent communication by Thacker et al. reported yields of chromosomal exchange aberrations in V79 hamster cells after irradiation by either 250-kVp x rays or carbon characteristic K x rays of energy 270 eV. These latter produce photoelectrons with ranges of less than 10 nm. Such a distance makes it prima facie unlikely that two chromosomes could be damaged by a single track with a significant frequency. Thacker et al., however, discuss the observed effective linear component of induction of chromosome exchanges by ultrasoft carbon x-rays, and are thus led to consider the possibility that only one chromosome needs to be damaged by radiation to lead to an exchange event. In this paper, the authors analyze the data of Thacker et al. using a simple model. For carbon x rays they take advantage of the fact that the cell nuclei are not subject to a distribution of specific energies, but will each undergo essentially the same number of photon absorption events (each consisting of an energy deposition of 270 eV) for a given dose. They define the probability that a given chromosome will be broken as a result of an energy deposition event. They further define the probability that two chromosomes will be broken as a result of a single energy deposition event

  18. Chromosome aberrations and transforming genes in leukemic and non-leukemic patients with a history of atomic bomb exposure

    International Nuclear Information System (INIS)

    To investigate leukemogenesis in atomic bomb (A-bomb) survivors, chromosome aberrations in bone marrow cells, and T- and B-lymphocytes from 135 healthy persons who had been exposed within 1,000 m of the hypocenter of the Hiroshima A-bomb were sequentially examined. Leukemic marrow cells from 468 patients with acute or chronic type of leukemias, including 25 acute leukemias exposed to 1 rad or more of radiation were also studied cytogenetically. Analysis of breakpoints observed in T-lymphocytes with stable types of abnormalities revealed a nonrandom distribution, and clustering in specific regions of chromosomes such as 22q1, 14q3, and 5q3. Statistical analysis revealed a higher incidence of translocations in 50 bands, including those containing cellular oncogenes such as 8q22, 8q24, and 9q34. Of these 50 bands, 20 were matched with bands specific for leukemia and cancer and 14 with constitutive fragile sites. In leukemic marrow, all 10 patients who had been exposed to radiation of more than 200 rad and then developed acute non-lymphocytic leukemia had chromosome aberrations. Their aberrations were more complex than those in patients exposed to less than 200 rad (33 patients) and in the non-exposed patients (134 patients). DNA samples extracted from bone marrow cells of 13 survivors, including 4 healthy survivors with more than 30% chromosome abnormalities in the bone marrow and 9 leukemia patients were used for in vivo selection assay of transforming genes. Tumor formation in nude mice was observed in 3 of the 4 healthy survivors and 9 leukemia patients. All of the transfectants were shown to contain Alu sequences. The transforming N-ras gene was detected for the first time in the bone marrow cells from 3 heavily exposed survivors and from 7 leukemia patients with a history of radiation exposure

  19. INCIDENCE OF CHROMOSOME ABERRATIONS IN MAMMALIAN SPERM STAINED WITH HOECHST 33342 AND UV-LASER IRRADIATED DURING FLOW SORTING

    Science.gov (United States)

    The separation of two sperm populations is possible using the technique of flow sorting, provided that a significant difference exists in the DNA content of X- and Y-bearing sperm. In order to ascertain whether or not chromosome damage was induced in sorted sperm, chromosome prep...

  20. Genomic copy number analysis of a spectrum of blue nevi identifies recurrent aberrations of entire chromosomal arms in melanoma ex blue nevus.

    Science.gov (United States)

    Chan, May P; Andea, Aleodor A; Harms, Paul W; Durham, Alison B; Patel, Rajiv M; Wang, Min; Robichaud, Patrick; Fisher, Gary J; Johnson, Timothy M; Fullen, Douglas R

    2016-03-01

    Blue nevi may display significant atypia or undergo malignant transformation. Morphologic diagnosis of this spectrum of lesions is notoriously difficult, and molecular tools are increasingly used to improve diagnostic accuracy. We studied copy number aberrations in a cohort of cellular blue nevi, atypical cellular blue nevi, and melanomas ex blue nevi using Affymetrix's OncoScan platform. Cases with sufficient DNA were analyzed for GNAQ, GNA11, and HRAS mutations. Copy number aberrations were detected in 0 of 5 (0%) cellular blue nevi, 3 of 12 (25%) atypical cellular blue nevi, and 6 of 9 (67%) melanomas ex blue nevi. None of the atypical cellular blue nevi displayed more than one aberration, whereas complex aberrations involving four or more regions were seen exclusively in melanomas ex blue nevi. Gains and losses of entire chromosomal arms were identified in four of five melanomas ex blue nevi with copy number aberrations. In particular, gains of 1q, 4p, 6p, and 8q, and losses of 1p and 4q were each found in at least two melanomas. Whole chromosome aberrations were also common, and represented the sole finding in one atypical cellular blue nevus. When seen in melanomas, however, whole chromosome aberrations were invariably accompanied by partial aberrations of other chromosomes. Three melanomas ex blue nevi harbored aberrations, which were absent or negligible in their precursor components, suggesting progression in tumor biology. Gene mutations involving GNAQ and GNA11 were each detected in two of eight melanomas ex blue nevi. In conclusion, copy number aberrations are more common and often complex in melanomas ex blue nevi compared with cellular and atypical cellular blue nevi. Identification of recurrent gains and losses of entire chromosomal arms in melanomas ex blue nevi suggests that development of new probes targeting these regions may improve detection and risk stratification of these lesions. PMID:26743478

  1. Individual and combined effects of ochratoxin A and citrinin on viability and DNA fragmentation in cultured Vero cells and on chromosome aberrations in mice bone marrow cells

    International Nuclear Information System (INIS)

    Ochratoxin A (OTA) and citrinin (CTN) are two common contaminant mycotoxins which can occur jointly in a wide range of food commodities. Both mycotoxins have several toxic effects but share a significant nephrotoxic and carcinogenic potential since OTA and CTN were reported to be responsible for naturally occurring human and animal kidney diseases and tumors. Considering the concomitant production of OTA and CTN, it is very likely that humans and animals are always exposed to the mixture rather than to individual compounds. Therefore, the aim of the present study was to investigate, in vivo and in vitro, whether DNA damage is enhanced by combination of both mycotoxins as compared to their effect separately. To this end, we have assessed their effects individually or combined on cell proliferation and DNA fragmentation in cultured Vero cells and in vivo by monitoring the induction of chromosome aberrations. Our results clearly showed that cultured renal cells respond to OTA and CTN exposure by a moderate and weak inhibition of cell proliferation, respectively. However, when combined, they exert a significant increase in inhibition of cell viability. Similar results were found for the investigated genotoxicity endpoints (DNA fragmentation and chromosome aberrations). Altogether, our study showed that OTA and CTN combination effects are clearly synergistic. The synergistic induction of DNA damage observed with OTA and CTN taken concomitantly could be relevant to explain the molecular basis of the renal diseases and tumorogenesis induced by naturally occurring mycotoxins

  2. Growth rate of late passage sarcoma cells is independent of epigenetic events but dependent on the amount of chromosomal aberrations

    International Nuclear Information System (INIS)

    Soft tissue sarcomas (STS) are characterized by co-participation of several epigenetic and genetic events during tumorigenesis. Having bypassed cellular senescence barriers during oncogenic transformation, the factors further affecting growth rate of STS cells remain poorly understood. Therefore, we investigated the role of gene silencing (DNA promoter methylation of LINE-1, PTEN), genetic aberrations (karyotype, KRAS and BRAF mutations) as well as their contribution to the proliferation rate and migratory potential that underlies “initial” and “final” passage sarcoma cells. Three different cell lines were used, SW982 (synovial sarcoma), U2197 (malignant fibrous histiocytoma (MFH)) and HT1080 (fibrosarcoma). Increased proliferative potential of final passage STS cells was not associated with significant differences in methylation (LINE-1, PTEN) and mutation status (KRAS, BRAF), but it was dependent on the amount of chromosomal aberrations. Collectively, our data demonstrate that these fairly differentiated/advanced cancer cell lines have still the potential to gain an additional spontaneous growth benefit without external influences and that maintenance of increased proliferative potential towards longevity of STS cells (having crossed senescence barriers) may be independent of overt epigenetic alterations. -- Highlights: Increased proliferative potential of late passage STS cells was: • Not associated with epigenetic changes (methylation changes at LINE-1, PTEN). • Not associated with mutation status of KRAS, BRAF. • Dependent on presence/absence of chromosomal aberrations

  3. Growth rate of late passage sarcoma cells is independent of epigenetic events but dependent on the amount of chromosomal aberrations

    Energy Technology Data Exchange (ETDEWEB)

    Becerikli, Mustafa; Jacobsen, Frank; Rittig, Andrea; Köhne, Wiebke [Department of Plastic Surgery, BG University Hospital Bergmannsheil, Ruhr-University Bochum (Germany); Nambiar, Sandeep; Mirmohammadsadegh, Alireza; Stricker, Ingo; Tannapfel, Andrea [Institute of Pathology, Ruhr-University Bochum (Germany); Wieczorek, Stefan; Epplen, Joerg Thomas [Department of Human Genetics, Ruhr-University Bochum (Germany); Tilkorn, Daniel [Department of Plastic Surgery, BG University Hospital Bergmannsheil, Ruhr-University Bochum (Germany); Steinstraesser, Lars, E-mail: lars.steinstraesser@rub.de [Department of Plastic Surgery, BG University Hospital Bergmannsheil, Ruhr-University Bochum (Germany)

    2013-07-15

    Soft tissue sarcomas (STS) are characterized by co-participation of several epigenetic and genetic events during tumorigenesis. Having bypassed cellular senescence barriers during oncogenic transformation, the factors further affecting growth rate of STS cells remain poorly understood. Therefore, we investigated the role of gene silencing (DNA promoter methylation of LINE-1, PTEN), genetic aberrations (karyotype, KRAS and BRAF mutations) as well as their contribution to the proliferation rate and migratory potential that underlies “initial” and “final” passage sarcoma cells. Three different cell lines were used, SW982 (synovial sarcoma), U2197 (malignant fibrous histiocytoma (MFH)) and HT1080 (fibrosarcoma). Increased proliferative potential of final passage STS cells was not associated with significant differences in methylation (LINE-1, PTEN) and mutation status (KRAS, BRAF), but it was dependent on the amount of chromosomal aberrations. Collectively, our data demonstrate that these fairly differentiated/advanced cancer cell lines have still the potential to gain an additional spontaneous growth benefit without external influences and that maintenance of increased proliferative potential towards longevity of STS cells (having crossed senescence barriers) may be independent of overt epigenetic alterations. -- Highlights: Increased proliferative potential of late passage STS cells was: • Not associated with epigenetic changes (methylation changes at LINE-1, PTEN). • Not associated with mutation status of KRAS, BRAF. • Dependent on presence/absence of chromosomal aberrations.

  4. Distribution of radiation-induced G1 exchange and terminal deletion breakpoints in Chinese hamster chromosomes as detected by G banding

    International Nuclear Information System (INIS)

    A total of 255 chromosomal aberrations induced by X-rays in G1 phase of the cell cycle were scored in 600 G-banded metaphases prepared from Chinese hamster female cells. On the basis of a detailed analysis of these aberrations a total of 441 chromosomal breakpoints were mapped to the individual Chinese hamster chromosomes and their bands. More breakpoints were mapped to G-light (80.5%) than to G-dark (19.5%) bands. These results indicate that radiation-induced exchange and terminal deletion breakpoints, as observed in the first postirradiation metaphase, have different patterns of distribution in Chinese hamster chromosomes. Clustering of terminal deletions in the long arms of X chromosomes, which are entirely occupied by heterochromatin, suggests that chromosomal repair mechanisms responsible for rejoining of chromosomal breaks are less effective in heterochromatic than in other genomic regions. (author)

  5. Chromosomal Aberrations in UVB-induced Tumors of Immunosuppressed Mice

    OpenAIRE

    Dworkin, Amy M.; Tober, Kathleen L.; Duncan, F. Jason; Yu, Lianbo; VanBuskirk, Anne M.; Obersyzyn, Tatiana M.; Toland, Amanda Ewart

    2009-01-01

    In immunocompromised individuals, such as organ transplant recipients, the risk of cutaneous squamous cell carcinoma (SCC) is increased 60-250 fold, and there is an increased likelihood to develop aggressive, metastatic SCC. An understanding of the genes involved in SCC tumorigenesis is critical to prevent SCC-associated morbidity and mortality. Mouse models show that different immunosuppressive drugs lead to SCCs varying in size, number, and malignant potential. In this study we utilized mou...

  6. Chromosome misalignments induce spindle-positioning defects.

    Science.gov (United States)

    Tame, Mihoko A; Raaijmakers, Jonne A; Afanasyev, Pavel; Medema, René H

    2016-03-01

    Cortical pulling forces on astral microtubules are essential to position the spindle. These forces are generated by cortical dynein, a minus-end directed motor. Previously, another dynein regulator termed Spindly was proposed to regulate dynein-dependent spindle positioning. However, the mechanism of how Spindly regulates spindle positioning has remained elusive. Here, we find that the misalignment of chromosomes caused by Spindly depletion is directly provoking spindle misorientation. Chromosome misalignments induced by CLIP-170 or CENP-E depletion or by noscapine treatment are similarly accompanied by severe spindle-positioning defects. We find that cortical LGN is actively displaced from the cortex when misaligned chromosomes are in close proximity. Preventing the KT recruitment of Plk1 by the depletion of PBIP1 rescues cortical LGN enrichment near misaligned chromosomes and re-establishes proper spindle orientation. Hence, KT-enriched Plk1 is responsible for the negative regulation of cortical LGN localization. In summary, we uncovered a compelling molecular link between chromosome alignment and spindle orientation defects, both of which are implicated in tumorigenesis. PMID:26882550

  7. Non-linear character of dose dependences of chromosome aberration frequency in radiation-damaged root

    International Nuclear Information System (INIS)

    The dose dependences of the aberrant anaphases in the root meristem in 48 hours after the irradiation have non-linear character and a plateau in the region about 6-8 Gy. The plateau indicates the activation of recovery processes. In the plateau range, the level of damages for this genotype is 33% for aberrant anaphases (FAA), 2.3 aberrations per aberrant anaphase (A/AC), and 0.74 aberrations for the total number of anaphases. At 10 Gy, the dose curve forms the exponential region caused by the involvement of the large number of new cells with unrepaired damages in the mutation process. The increase of A/AC to 1.1 indicate the ''criticality'' of the meristem radiation damage.

  8. Method for measuring ocular aberrations induced by thermal lensing in vivo

    Science.gov (United States)

    Vincelette, Rebecca; Oliver, Jeff; Noojin, Gary; Schuster, Kurt; Shingledecker, Aurora; Welch, Ashley J.

    2010-02-01

    An adaptive optics imaging system was used to qualitatively observe the types of aberrations induced by an infrared laser in a rhesus eye. Thermal lensing was induced with an infrared laser radiation wavelength of 1150-nm. The adaptive optics system tracked the temporal response of the aberrations at a frequency of 30 Hz for continuous-wave exposures. Results are compared against thermal lensing aberrations induced in an artificial eye.

  9. The impact of homologous recombination repair deficiency on depleted uranium clastogenicity in Chinese hamster ovary cells: XRCC3 protects cells from chromosome aberrations, but increases chromosome fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, Amie L. [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth Street, P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Joyce, Kellie [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Xie, Hong [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth Street, P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Falank, Carolyne [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); and others

    2014-04-15

    Highlights: • The role of homologous recombination repair in DU-induced toxicity was examined. • Loss of RAD51D did not affect DU-induced cytotoxicity or genotoxicity. • XRCC3 protects cell from DU-induced chromosome breaks and fusions. • XRCC3 plays a role in DU-induced chromosome fragmentation of the X chromosome. - Abstract: Depleted uranium (DU) is extensively used in both industry and military applications. The potential for civilian and military personnel exposure to DU is rising, but there are limited data on the potential health hazards of DU exposure. Previous laboratory research indicates DU is a potential carcinogen, but epidemiological studies remain inconclusive. DU is genotoxic, inducing DNA double strand breaks, chromosome damage and mutations, but the mechanisms of genotoxicity or repair pathways involved in protecting cells against DU-induced damage remain unknown. The purpose of this study was to investigate the effects of homologous recombination repair deficiency on DU-induced genotoxicity using RAD51D and XRCC3-deficient Chinese hamster ovary (CHO) cell lines. Cells deficient in XRCC3 (irs1SF) exhibited similar cytotoxicity after DU exposure compared to wild-type (AA8) and XRCC3-complemented (1SFwt8) cells, but DU induced more break-type and fusion-type lesions in XRCC3-deficient cells compared to wild-type and XRCC3-complemented cells. Surprisingly, loss of RAD51D did not affect DU-induced cytotoxicity or genotoxicity. DU induced selective X-chromosome fragmentation irrespective of RAD51D status, but loss of XRCC3 nearly eliminated fragmentation observed after DU exposure in wild-type and XRCC3-complemented cells. Thus, XRCC3, but not RAD51D, protects cells from DU-induced breaks and fusions and also plays a role in DU-induced chromosome fragmentation.

  10. Dynamic Investigation on Chromosome Aberration of a Human Retinoblastoma Cell Line SO-Rb_(50)

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    G-banding and karyotype analyses of cells in seventeen passages of SO-Rb_(50) during a long period of culture for about four years were performed. Three chromosome markers 13q14~-, 1p36~+ and 12p13~+ were found. Cells possessed 13q14~- reduced to zero after the 200th passage while 1p~+ and 12p~+ cells increased to 100% after 30 and 200 passages respectively. Abnormal chromosomes, ring chromosomes, chromosome radiuses and double minutes were also observed. These chromosomal changes were more often seen b...

  11. Distribution of X-ray-induced chromosome breakpoints in Down syndrome lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Shafik, H.M.; Au, W.W.; Whorton, E.B. Jr.; Legator, M.S. (Univ. of Texas Medical Branch, Galveston (USA))

    1990-01-01

    Down syndrome (DS) individuals are known to be predisposed to develop leukemia and their lymphocytes are highly sensitive to the induction of chromosome aberrations by X-rays. A study was conducted to identify the chromosome breakpoints and to evaluate whether site specificity for chromosome breakage and rearrangement may exist which may explain the predisposition phenomenon. DS lymphocytes at the G1 phase of the cell cycle were irradiated with 300, 450, and 600 rad of X-rays. Cells were harvested after 3 days in culture and 193 G-banded karyotypes were analyzed to identify the induced chromosome abnormalities. Out of 273 breakpoints identified, 122 were involved in the formation of stable chromosome rearrangements and 151 in the formation of unstable abnormalities. The Poisson analysis of these breakpoints demonstrated that 16 chromosome bands located in chromosomes 1, 3, 7, 12, 17, 19 and X were preferentially involved in breakage and rearrangement (P less than 0.05). These 16 bands are also found to be locations of cancer breakpoints, oncogenes, or fragile sites. Many abnormal cells were observed to carry stable chromosome rearrangements only. Therefore, these cells are presumed to be compatible with survival and to be initiated in the transformation process. We propose that similar stable and site-specific chromosome rearrangements may exist in proliferating cells in DS individuals after exposure to clastogens and that this abnormality predisposes them to develop leukemia.

  12. Distribution of X-ray-induced chromosome breakpoints in Down syndrome lymphocytes

    International Nuclear Information System (INIS)

    Down syndrome (DS) individuals are known to be predisposed to develop leukemia and their lymphocytes are highly sensitive to the induction of chromosome aberrations by X-rays. A study was conducted to identify the chromosome breakpoints and to evaluate whether site specificity for chromosome breakage and rearrangement may exist which may explain the predisposition phenomenon. DS lymphocytes at the G1 phase of the cell cycle were irradiated with 300, 450, and 600 rad of X-rays. Cells were harvested after 3 days in culture and 193 G-banded karyotypes were analyzed to identify the induced chromosome abnormalities. Out of 273 breakpoints identified, 122 were involved in the formation of stable chromosome rearrangements and 151 in the formation of unstable abnormalities. The Poisson analysis of these breakpoints demonstrated that 16 chromosome bands located in chromosomes 1, 3, 7, 12, 17, 19 and X were preferentially involved in breakage and rearrangement (P less than 0.05). These 16 bands are also found to be locations of cancer breakpoints, oncogenes, or fragile sites. Many abnormal cells were observed to carry stable chromosome rearrangements only. Therefore, these cells are presumed to be compatible with survival and to be initiated in the transformation process. We propose that similar stable and site-specific chromosome rearrangements may exist in proliferating cells in DS individuals after exposure to clastogens and that this abnormality predisposes them to develop leukemia

  13. Chemical and radiation-induced mutagenesis of the rat liver chromosomes

    International Nuclear Information System (INIS)

    It was shown that radiation and chemical mutagenesis in rat liver cells is determined chiefly by long-lived premutational potential changes. The intensification of intrachromosomal processes under the action of an inducer of gene activity - phenobarbital - does not modify the yield of chromosome aberrations, both under the action of radiation and under the action of an alkylating agent -dipin. The facts obtained support the hypothesis that the chemical nature of the premutational changes differs from the primary molecular damages to DNA. (author)

  14. Propagation of Aberrations through Phase Induced Amplitude Apodization coronagraph

    CERN Document Server

    Pueyo, Laurent; Shaklan, Stuart; 10.1364/JOSAA.28.000189

    2011-01-01

    The specification of polishing requirements for the optics in coronagraphs dedicated to exo-planet detection requires careful and accurate optical modelling. Numerical representations of the propagation of aberrations through the system as well as simulations of the broadband wavefront compensation system using multiple DMs are critical when one devises an error budget for such a class of instruments. In this communication we introduce an analytical tool that serves this purpose for Phase Induced Amplitude Apodisation (PIAA) coronagraphs. We first start by deriving the analytical form of the propagation of a harmonic ripple through a PIAA unit. Using this result we derive the chromaticity of the field at any plane in the optical train of a telescope equipped with such a coronagraph. Finally we study the chromatic response of a sequential DM wavefront actuator correcting such a corrugated field and thus quantify the requirements on the manufacturing of PIAA mirrors

  15. Stable type chromosome aberrations in the residents of the high background radiation area in China

    International Nuclear Information System (INIS)

    Chromosome translocations were analyzed by chromosome painting techniques using No.1, 2 and 4 whole chromosome painting probes to examine the effect of high-level natural radiation on the frequencies of chromosome translocations in human peripheral lymphocytes. The subjects were 5 children and 13 old men from the high background radiation area and 6 children and 11 old men from the control area. Children had lesser translocations and smaller variation compared with the old men. The frequency of translocations among the old subjects varied widely from person to person. There is no difference of the frequency of chromosome translocations between high background radiation area and control area. No effect of high-level natural background radiation on the frequencies of stable chromosome translocation was detected

  16. Higher frequencies of chromosomal aberrations in lymphocytes of children with acute lymphoblastic leukemia after in vitro gamma irradiation

    Directory of Open Access Journals (Sweden)

    A Ramyar

    2012-12-01

    Full Text Available Background: Acute lymphoblastic leukemia (ALL is the most common malignancy in childhood, characterized by excess lymphoblasts, and immature white blood cells that are continuously multiplying and overproducing in the bone marrow. The aim of this investigation was to measure the sensitivity of lymphocytes against gamma irradiation in patients with acute lymphoblastic leukemia, and also find out the effect of such irradiations in causing chromosomal abnormalities.Methods: In this investigation performed between April 2010 and July 2011, at the Department of Genetics, Cancer Institute of Iran, we studied the effects of gamma irradiation on the lymphocytes of 20 children with acute lymphoblastic leukemia. The lymphocytes of 30 healthy donors were used to establish as a normal response to gamma irradiation and seven age-matched ataxia telangiectasia patients were recruited as positive control. The chromosomal radiosensitivity was assessed with the G2- and the G0-assay. We compared the mean number of chromosomal abnormalities such as chromosome and chromatid breakages, chromosome and chromatid gaps, and chromatid exchanges in one-hundred metaphases of patients and control groups.Results: The frequency of chromosomal aberrations was statistically higher among patients with acute lymphoblastic leukemia than the normal controls (P<0.01. In total, 65% of the patients were sensitive to gamma irradiation, but the remaining 35% were similar to the normal controls. Patients with ataxia telangiectasia showed the highest sensitivity to gamma irradiation (P=0.001.Conclusion: Our results showed that a high percentage of patients with acute lymphoblastic leukemia were sensitive to irradiation, meaning that maximum care should be taken during their treatment to avoid unnecessary X-rays or radiotherapies.

  17. Radiation-induced chromosome damage in human lymphocytes

    International Nuclear Information System (INIS)

    Analysis for chromosome aberrations in human peripheral blood lymphocytes has been developed as an indicator of dose from ionising radiation. An outline is given of the mechanism of production of aberrations, the technique for their analysis and the dose-effect relationships for various types of radiation. During the past ten years the National Radiological Protection Board has developed a service for the UK in which estimates of dose from chromosomes aberration analysis are made on people known or suspected of being accidentally over-exposed. This service can provide estimates where no physical dosemeter was worn and is frequently able to resolve anomalous or disputed data from routine film badges. Several problems in the interpretation of chromosome aberration yields are reviewed. These include the effects of partial body irradiation and the response to variations in dose rate and the intermittent nature of some exposures. The dosimetry service is supported by a research programme which includes surveys of groups of patients irradiated for medical purposes. Two surveys are described. In the first, lymphocyte aberrations were examined in rheumatoid arthritis patients receiving intra-articular injections of colloidal radiogold or radioyttrium. A proportion of the nuclide leaked from the joint into the regional lymphatic system. In the second survey a comparison was made between the cytogenetic and physical estimates of whole body dose in patients receiving iodine 131 for thyroid carcinoma. (author)

  18. MFISH Measurements of Chromosomal Aberrations Individuals Exposed in Utero to Gamma-ray Doses from 5 to 20 cGy

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, David J.

    2009-11-17

    Our plan was to identify and obtain blood from 36 individuals from the Mayak-in-utero exposed cohort who were exposed in utero only to gamma ray does doses fro 5 to 20 cGy. Our goal is to do mFISH and in a new development, single-arm mFISH on these samples to measure stable chromosome aberrations in these now adult individuals. The results were compared with matched control individuals (same age, same gender) available from the large control population which we are studying in the context of our plutonium worker study. The long term goal was to assess the results both in terms of the sensitivity of the developing embryo/fetus to low doses of ionizing radiation, and in terms of different potential mechanisms (expanded clonal origin vs. induced instability) for an increased risk.

  19. RBE/dose relationship for neutrons produced by 50MeV deuterons determined by chromosome aberrations in Allium cepa

    International Nuclear Information System (INIS)

    RBE of neutrons produced at ''CYCLONE'' (Louvain-la-Neuve) was investigated for chromosome aberrations in onion roots (Allium Cepa). In experimental conditions, it was observed that the best criteria for evaluation of RBE were: criterion 1: the % of cells in anaphase or telophase showing at least one aberration or; criterion 2: the average number of aberrations per cell in anaphase or telophase. Five independent experiments were performed. For the first criterion, following RBE values were obtained as a function of the (neutron) absorbed dose; RBE=11, 8, 7 and 6.5 for 10, 20, 30 and 40 rad (neutron absorbed dose) respectively. RBE values obtained for the second criteria were somewhat higher: RBE=12, 10, 8 and 7 for 10, 20, 30 and 40 rad (neutron absorbed dose) respectively. When plotted in a logarithmic scale as a function of the neutron absorbed dose, RBE values obtained for the two criteria are situated on two rather parallel straight lines with a slope slightly less than -1/2

  20. Study on micronucleus frequency and chromosomal aberration ratios of mouse testicle cells induced by methylene-dioxymethamphetamine%3,4亚甲基二氧基甲基苯丙胺对小鼠微核率及染色体畸变率的影响

    Institute of Scientific and Technical Information of China (English)

    赵忠桂; 刘霜; 刘艳华; 李雅欣; 伍爱荣; 周业成

    2015-01-01

    目的:通过连续20 d对雄性小鼠灌胃染毒3,4亚甲基二氧基甲基苯丙胺(MDMA)后,探究MDMA对雄性小鼠睾丸组织细胞微核率及染色体畸变率的影响。方法将雄性小鼠随机数字表法分为 MDMA 低(5.0 mg/kg)、中(10.0 mg/kg)、高(20.0 mg/kg)3个染毒剂量组,采用0.9%氯化钠注射液做阴性对照,每日染毒1次。于末次给药后第2天,取小鼠睾丸组织细胞,采用常规微核(MN)试验,检测小鼠睾丸细胞微核率的改变;同时采用染色体畸变试验探究MDMA对小鼠睾丸细胞染色体畸变率的影响。结果微核试验结果表明MDMA高剂量与低剂量组小鼠睾丸细胞微核率及阴性对照组比较,差异有统计学意义(P<0.01)。染色体畸变试验结果中,MDM高、中剂量组染色体畸变率分别与阴性对照组比较,差异有统计学意义(P<0.05),高剂量组与中、低剂量组染色体畸变率比较差异有统计学意义(P<0.05)。结论高剂量组MDMA能诱导小鼠睾丸组织细胞微核率增加,高剂量组及中剂量组可以使小鼠睾丸细胞染色体畸变率增高,说明其对雄性小鼠睾丸遗传物质有一定的损伤效应。%Objective To study the effects of 3,4-methylenedioxymethamphetamine (MDMA) on micronucleus frequency and chromosomal aberration ratios of male mouse testicle cells. Methods Healthy adult male rats were randomly divided into four groups. Different doses of MDMA (0, 5, 10 and 20 mg/kg) were administrated to the rats every days for 20 days. The rats were killed after the last test substance given for 24 h. Each rat′s micronucleus frequency and chromosomal aberration ratio of testicle cell were detected by using micronucleus test and chromosomal aberration test. Results The micronucleus frequencies of rats testicle cell in high dose group was significantly different from the control group and low dose group(P<0.01). With the control group, the

  1. Array painting: a protocol for the rapid analysis of aberrant chromosomes using DNA microarrays

    Science.gov (United States)

    Gribble, Susan M; Ng, Bee Ling; Prigmore, Elena; Fitzgerald, Tomas; Carter, Nigel P

    2012-01-01

    Aarray painting is a technique that uses microarray technology to rapidly map chromosome translocation breakpoints. previous methods to map translocation breakpoints have used fluorescence in situ hybridization (FIsH) and have consequently been labor-intensive, time-consuming and restricted to the low breakpoint resolution imposed by the use of metaphase chromosomes. array painting combines the isolation of derivative chromosomes (chromosomes with translocations) and high-resolution microarray analysis to refine the genomic location of translocation breakpoints in a single experiment. In this protocol, we describe array painting by isolation of derivative chromosomes using a MoFlo flow sorter, amplification of these derivatives using whole-genome amplification and hybridization onto commercially available oligonucleotide microarrays. although the sorting of derivative chromosomes is a specialized procedure requiring sophisticated equipment, the amplification, labeling and hybridization of Dna is straightforward, robust and can be completed within 1 week. the protocol described produces good quality data; however, array painting is equally achievable using any combination of the available alternative methodologies for chromosome isolation, amplification and hybridization. PMID:19893508

  2. DNA lesions induced by replication stress trigger mitotic aberration and tetraploidy development.

    Directory of Open Access Journals (Sweden)

    Yosuke Ichijima

    Full Text Available During tumorigenesis, cells acquire immortality in association with the development of genomic instability. However, it is still elusive how genomic instability spontaneously generates during the process of tumorigenesis. Here, we show that precancerous DNA lesions induced by oncogene acceleration, which induce situations identical to the initial stages of cancer development, trigger tetraploidy/aneuploidy generation in association with mitotic aberration. Although oncogene acceleration primarily induces DNA replication stress and the resulting lesions in the S phase, these lesions are carried over into the M phase and cause cytokinesis failure and genomic instability. Unlike directly induced DNA double-strand breaks, DNA replication stress-associated lesions are cryptogenic and pass through cell-cycle checkpoints due to limited and ineffective activation of checkpoint factors. Furthermore, since damaged M-phase cells still progress in mitotic steps, these cells result in chromosomal mis-segregation, cytokinesis failure and the resulting tetraploidy generation. Thus, our results reveal a process of genomic instability generation triggered by precancerous DNA replication stress.

  3. Chromosomal aberrations in peripheral lymphocytes from A-bomb survivors who entered the city early after A-bombing

    International Nuclear Information System (INIS)

    It has been thought that A-bomb survivors who entered the city early after A-bombing were exposed to residual A-bomb radiation both externally and internally (through inhalation, food, drink or skin). This paper summarizes the data on estimated radiation doses in A-bomb survivors who entered Hiroshima within 3 days after A-bombing based on the chromosome staining analysis of lymphocytes of peripheral blood taken from A-bomb survivors. The subjects were 40 A-bomb survivors; according to a stay period and a history of medical irradiation, they were divided into four: group A with a long stay, group B with a long stay + medical irradiation, group C with a short stay, and group D with a short stay + medical irradiation. A mean estimated radiation dose was 4.8 rad (one rad or less to 13.5 rad) in group A, 13.9 rad (one rad or less to 71.2 rad) in group B, one rad or less in group C, and 1.9 rad (one rad or less to 21.2 rad) in group D. The highest rate of chromosomal aberrations was 3.1% in group B, followed by 2.1% in group A, 0.83% in group D, and 0.73% in group C. The frequency of chromosomal aberrations was coincident with the duration of stay in the city. Furthermore, medical irradiation seemed to have contributed to the additional effects of A-bomb radiation. (N.K.)

  4. Recurrent chromosomal aberrations in intravenous leiomyomatosis of the uterus: high-resolution array comparative genomic hybridization study.

    Science.gov (United States)

    Buza, Natalia; Xu, Fang; Wu, Weiqing; Carr, Ryan J; Li, Peining; Hui, Pei

    2014-09-01

    Uterine intravenous leiomyomatosis (IVL) is a distinct smooth muscle neoplasm with a potential of clinical aggressiveness due to its ability to extend into intrauterine and extrauterine vasculature. In this study, chromosomal alterations analyzed by oligonucleotide array comparative genomic hybridization were performed in 9 cases of IVL. The analysis was informative in all cases with multiple copy number losses and/or gains observed in each tumor. The most frequent recurrent loss of 22q12.3-q13.1 was observed in 6 tumors (66.7%), followed by losses of 22q11.23-q13.31, 1p36.13-p33, 2p25.3-p23.3, and 2q24.2-q32.2 and gains of 6p22.2, 2q37.3 and 10q22.2-q22.3, in decreasing order of frequency. Copy number variants were identified at 14q11.2, 15q11.1-q11.2, and 15q26.2. Genes mapping to the regions of loss include CHEK2, EWS, NF2, PDGFB, and MAP3K7IP1 on chromosome 22q, HEI10 on chromosome 14q, and succinate dehydrogenase subunit B, E2F2, ARID1A KPNA6, EIF3S2 , PTCH2, and PIK3R3 on chromosome 1p. Regional losses on chromosomes 22q and 1p and gains on chromosomes 12q showed overlaps with those previously observed in uterine leiomyosarcomas. In addition, presence of multiple chromosomal aberrations implies a higher level of genetic instability. Follow-up polymerase chain reaction (PCR) sequencing analysis of MED12 gene revealed absence of G> A transition at nucleotides c.130 or c.131 in all 9 cases, a frequent mutation found in uterine leiomyoma and its variants. In conclusion, this is the first report of high-resolution, genome-wide investigation of IVL by oligonucleotide array comparative genomic hybridization. The presence of high frequencies of recurrent regional loss involving several chromosomes is an important finding and likely related to the pathogenesis of the disease. PMID:25033729

  5. The use of unstable chromosome aberrations and micronuclei in the individual biomonitoring: a comparative study; Emprego das aberracoes cromossomicas instaveis e micronucleos no biomonitoramento individual: estudo comparativo

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Thiago de Salazar e

    2005-02-15

    Biodosimetry is based on the investigation of radioinduced biological effects in order to correlate them with the absorbed dose. The quantification of unstable chromosome aberrations and micronuclei, in peripheral blood lymphocytes, are two methods commonly used in biodosimetry. In this context, the aim of this research was to compare these methods in the biomonitoring of health care professionals occupationally exposed to ionizing radiation. In parallel, the technique of C-banding was evaluated for quality control of unstable chromosome aberrations analyses. Thus, samples of peripheral blood from health care professionals of three hospitals from Recife (Brazil) were collected, and the lymphocytes cultures were carried out based on the cytogenetic classical technique. It was pointed out that analysis of micronuclei is faster than the unstable chromosome aberrations ones, which suggests the use of the former in preliminary evaluation in cases of suspected accidental exposure. C-banding technique was efficient, as confirmatory test, in the identification of dicentrics and rings during the analyses of unstable chromosome aberrations, being able to be applied in the quality control in biodosimetry. The comparison between the individual work conditions with the frequencies of unstable aberrations and micronuclei obtained from cytogenetic analysis, resulted in the change of behavior of the professionals involved in this research, with a better observance of the radioprotection standards. (author)

  6. Evaluation of chromosome aberration frequency instable in individual groups residents at the municipality of Monte Alegre, Para, Brazil, exposed to radon

    International Nuclear Information System (INIS)

    The municipality of Monte Alegre is a region that presents natural radiation high due to the presence of the radionuclide uranium (238U) in its soil, which through its decay gives rise to element Rn, a gas. The radioactivity of the rocks has become a problem for the population of Monte Alegre, from the moment when the radioactive material began to be used in the construction of houses and paving of streets. Among all bio markers related to environmental exposures and its biological effects, the chromosomal aberrations are considered good bio markers as predictors of the risk of cancer. Studies suggest that the frequency of chromosomal aberrations may be related to the genetic instability individual and/or exposure to ionizing radiation. Our work aimed to evaluate the frequency of chromosomal aberrations in individuals in the region of high natural radioactivity in Monte Alegre-PA. As well as to correlate the cytogenetic analysis made in this study with the results of analysis of frequency of polymorphisms of genes of DNA repair carried out in another study that resulted in other dissertation. In accordance with the distribution of the data obtained in characterizing environmental radiological and in the calculation of dose, were chosen residents of homes with more and less exposure to radiation. The samples of peripheral blood of 85 individuals of the resident population of the region of Monte Alegre - PA were collected and examine provided two slides for individual was performed to verify the quality of the sample. Through this evaluation we decide that 33% of the material collected, or is, samples of 28 individuals were in suitable conditions for analysis of the frequency of chromosomal aberrations. After the collections lymphocytes present in the sample were cultivated in accordance with the methodology proposed for obtaining of cells in metaphase. were analyzed 6,177 metaphases of 28 individuals among which were found dicentric chromosomes 4 and 19 fragments

  7. Influence of duration of fixation on the yield of chromosome aberrations in human lumphocyte culture exposed to γ-radiation at different mitotic cycle stages

    International Nuclear Information System (INIS)

    A comparative study was made of the yield of chromosome aberrations in human lymphocyte culture exposed to 60Co- γ-rays (2 Gy) at different mitotic cycle stages the cells being fixed after 52 and 60 hr. It was shown that with the latter fixation time (60 hr) the frequency of chromosome aberrations after irradiation in G1 stage was substantially lower than that with the former one (52 hr) and, vice versa, it was higher after irradiation in S and G2 stages. The authors discuss the probable causes of the distinctions observed

  8. Influence of duration of fixation on the yield of chromosome aberrations in human lumphocyte culture exposed to. gamma. -radiation at different mitotic cycle stages

    Energy Technology Data Exchange (ETDEWEB)

    Sevan' kaev, A.V.; Bogatykh, B.A.; Lychev, V.A. (Akademiya Meditsinskikh Nauk SSSR, Obninsk. Nauchno-Issledovatel' skij Inst. Meditsinskoj Radiologii)

    A comparative study was made of the yield of chromosome aberrations in human lymphocyte culture exposed to /sup 60/Co- ..gamma..-rays (2 Gy) at different mitotic cycle stages the cells being fixed after 52 and 60 hr. It was shown that with the latter fixation time (60 hr) the frequency of chromosome aberrations after irradiation in G/sub 1/ stage was substantially lower than that with the former one (52 hr) and, vice versa, it was higher after irradiation in S and G/sub 2/ stages. The authors discuss the probable causes of the distinctions observed.

  9. The impact of homologous recombination repair deficiency on depleted uranium clastogenicity in Chinese hamster ovary cells: XRCC3 protects cells from chromosome aberrations, but increases chromosome fragmentation.

    Science.gov (United States)

    Holmes, Amie L; Joyce, Kellie; Xie, Hong; Falank, Carolyne; Hinz, John M; Wise, John Pierce

    2014-04-01

    Depleted uranium (DU) is extensively used in both industry and military applications. The potential for civilian and military personnel exposure to DU is rising, but there are limited data on the potential health hazards of DU exposure. Previous laboratory research indicates DU is a potential carcinogen, but epidemiological studies remain inconclusive. DU is genotoxic, inducing DNA double strand breaks, chromosome damage and mutations, but the mechanisms of genotoxicity or repair pathways involved in protecting cells against DU-induced damage remain unknown. The purpose of this study was to investigate the effects of homologous recombination repair deficiency on DU-induced genotoxicity using RAD51D and XRCC3-deficient Chinese hamster ovary (CHO) cell lines. Cells deficient in XRCC3 (irs1SF) exhibited similar cytotoxicity after DU exposure compared to wild-type (AA8) and XRCC3-complemented (1SFwt8) cells, but DU induced more break-type and fusion-type lesions in XRCC3-deficient cells compared to wild-type and XRCC3-complemented cells. Surprisingly, loss of RAD51D did not affect DU-induced cytotoxicity or genotoxicity. DU induced selective X-chromosome fragmentation irrespective of RAD51D status, but loss of XRCC3 nearly eliminated fragmentation observed after DU exposure in wild-type and XRCC3-complemented cells. Thus, XRCC3, but not RAD51D, protects cells from DU-induced breaks and fusions and also plays a role in DU-induced chromosome fragmentation. PMID:24561002

  10. Status of human chromosome aberrations as a biological radiation dosimeter in the nuclear industry

    International Nuclear Information System (INIS)

    It seems that the determination of peripheral lymphocyte chriomosome aberration levels is now firmly established as a means of biological dosimetry of great value in many phases of the nuclear industry. In the case of large external exposure it can provide valuable quantitative estimates, as well as information on dose distribution and radiation quality. In the case of routine occupational exposures the technique is more qualitative, but is of value particularly in resolving uncertainties as to whether suspected overexposures did in fact occur. Where workers accumulate burdens of internal emitters, aberration analysis provides a valuable, though at present quite qualitative indicator. In spite of the expense of cytogenetic analyses, they are of sufficient value to justify much more widespread application, particularly in high risk situations

  11. The incidence of unstable chromosome aberrations in peripheral blood lymphocytes from occupationally exposed people in Boris Kidric Institute of nuclear sciences (Radiation protection department)

    International Nuclear Information System (INIS)

    The results of the chromosome analysis of 17 employees of Radiation protection department of Boris Kidric Institute of Nuclear Sciences were related to the corresponding values of thermoluminescence dosimetry (TLD) measurements within the past eight years. The results obtained show the biological effects (structural chromosome aberrations) of chronic of fractionated exposures, low-level acute doses, even in the cases when the individual cumulative equivalent doses were 10 times lower than the order of maximum permissible occupational exposures (author)

  12. Influence of diagnostic roentgen doses on human chromosomes and influence of age on the aberration yield

    International Nuclear Information System (INIS)

    Urography was performed in 2 groups of patients (one comprising patients aged 7-18 years, the other patients aged 8-32 months) under constant conditions. The skin dose ranged between 1 and 4 R. Blood samples were taken before, immediately after and 24 hours after the irradiation. A significantly increased number of aberrant cells was found only in the blood samples taken 24 hours after irradiation. No age-dependent influence on the radiation sensitivity in vivo was found. (author)

  13. RBE of 650-MeV helium ions at different depths for chromosome aberrations in Allium cepa

    International Nuclear Information System (INIS)

    Induction of chromosome aberrations in Allium cepa onion roots has been used as biological criterion in order to determine the RBE of 650-MeV helium ions as a function of depth. These experiments were carried out at the synchrotron Saturne at Saclay (France). The Bragg peak of the helium ion beam was spread out, over a depth of about 5 cm, by means of a 'ridge filter'. RBE of the 650-MeV helium ions was determined at the beginning (13 cm in depth), middle (15 cm) and end (17 cm) of the spread-out Bragg peak using as reference radiation quality the initial plateau (2 cm in depth). (orig./MG)

  14. Chromosome aberration and environmental physical activity: Down syndrome and solar and cosmic ray activity, Israel, 1990-2000

    Science.gov (United States)

    Stoupel, Eliahu G.; Frimer, Helena; Appelman, Zvi; Ben-Neriah, Ziva; Dar, Hanna; Fejgin, Moshe D.; Gershoni-Baruch, Ruth; Manor, Esther; Barkai, Gad; Shalev, Stavit; Gelman-Kohan, Zully; Reish, Orit; Lev, Dorit; Davidov, Bella; Goldman, Boleslaw; Shohat, Mordechai

    2005-09-01

    The possibility that environmental effects are associated with chromosome aberrations and various congenital pathologies has been discussed previously. Recent advances in the collection and computerization of data make studying these potential associations more feasible. The aim of this study was to investigate a possible link between the number of Down syndrome (DS) cases detected prenatally or at birth yearly in Israel over a 10-year period compared with the levels of solar and cosmic ray activity 1 year before the detection or birth of each affected child. Information about 1,108,449 births was collected for the years 1990-2000, excluding 1991, when data were unavailable. A total of 1,310 cases of DS were detected prenatally or at birth—138 in the non-Jewish community and 1,172 in the Jewish population. Solar activity indices—sunspot number and solar radio flux 2,800 MHz at 10.7 cm wavelength for 1989-1999—were compared with the number of DS cases detected. Pearson correlation coefficients (r) and their probabilities (P) were established for the percentage of DS cases in the whole population. There was a significant inverse correlation between the indices of solar activity and the number of cases of DS detected—r=-0.78, P=0.008 for sunspot number and r=-0.76, P=0.01 for solar flux. The possibility that cosmophysical factors inversely related to solar activity play a role in the pathogenesis of chromosome aberrations should be considered. We have confirmed a strong trend towards an association between the cosmic ray activity level and the incidence of DS.

  15. Analysis of the frequency of unstable chromosome aberrations in human lymphocytes irradiated with {sup 60}Co; Analise da frequencia de alteracoes cromossomicas instaveis em linfocitos humanos irradiados com {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, Julyanne C.G.; Mendes, Mariana E.; Lima, Fabiana F., E-mail: july_cgm@hotmail.com, E-mail: mendes_sb@hotmail.com [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Santos, Neide, E-mail: santos_neide@yahoo.com.br [Universidade Federal de Pernambuco (CCB/UFPE), Recife, PE (Brazil). Departamento de Genetica

    2013-07-01

    The aim of this study was to analyze the frequency of unstable chromosomal aberrations induced by gamma radiation from a {sup 60}Co source at two different doses. Samples were obtained from a healthy donor and exposed to {sup 60}Co source (Gammacel 220 ) located in the Department of Nuclear Energy of Pernambuco Federal University (DEN/UFPe/Brazil) with a rate of air Kerma to 3,277 Gy/h. Exposures resulted in absorbed dose 0.51 Gy and 0.77 Gy. Mitotic metaphases were obtained by culturing lymphocytes for chromosome analysis and the slides were stained with 5% Giemsa. Among the unstable chromosomal aberrations the dicentric chromosomes, ring chromosomes and acentric fragments were analyzed. To calculate the significance level the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. To calculate the significance level of the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. The results showed that there was significant difference of the frequencies of dicentric chromosomes (from 0.18 to 0.51 to 0.37 Gy to 0.77 Gy), however there was no statistically significant difference between the frequencies of acentric fragments ( 0.054 to 0, 51 Gy to 0.063 to 0.77 Gy) and ring chromosomes (0.001 to 0.51 Gy to 0.003 to 0.77 Gy). The low number of rings is found justified, considering that in irradiated human lymphocytes, its appearance is rare relative to dicentrics. The results confirm that dicentrics are the most reliable biomarkers in estimating dose after exposure to gamma radiation. These two points will make the calibration curve dose-response being built for Biological Dosimetry Laboratory of CRCN-NE/CNEN.

  16. Unstable chromosome aberrations on peripheral blood lymphocytes from patients with cervical uterine cancer following radiotherapy; Aberracoes cromossomicas instaveis em linfocitos de pacientes com cancer de colo de utero

    Energy Technology Data Exchange (ETDEWEB)

    Magnata, Simey de Souza Leao Pereira

    2002-09-01

    Absorbed dose determination is an important step for risk assessment related to an exposure to ionizing radiation. However, physical dosimetry cannot be always performed, principally in the case of retrospective estimates. In this context, the use of bioindicators (biological effects) has been proposed, which defines the so-called biological dosimetry. In particular, scoring of unstable chromosomes aberrations (dicentrics, centric rings and fragments) of peripheral blood lymphocytes, while is the most reliable biological method for estimating individual exposure to ionizing radiation. In this work, blood samples from 5 patients, with cervical uterine cancer, were evaluated after partial-body radiotherapy with a source of {sup 69} Co. For this, conventional cytogenetic method was employed, based on Giemsa coloration and fluorescence in situ hybridization, in order to correlate the frequency of unstable chromosome aberrations of blood lymphocytes with absorbed dose, as a result of the radiotherapy. A good agreement was observed between the frequency of chromosome aberrations scored and the values of dose previously calculated by physical dosimetry during patient's radiotherapy. The results presented in this work point out the importance of concerning analyses of unstable chromosome aberrations as biological dosimeter in the investigation of partial-body exposure to ionizing radiation. (author)

  17. Dissection and cytological mapping of barley chromosome 2H in the genetic background of common wheat

    OpenAIRE

    Joshi, Giri Prasad; Nasuda, Shuhei; Endo, Takashi R.

    2011-01-01

    We used gametocidal (Gc) chromosomes 2C and 3C[SAT] to dissect barley 2H added to common wheat. The Gc chromosome induces chromosomal breakage resulting in chromosomal aberrations in the progeny of the 2H addition line of common wheat carrying the monosomic Gc chromosome. We conducted in situ hybridization to select plants carrying structurally rearranged aberrant 2H chromosomes and characterized them by sequential C-banding and in situ hybridization. We established 66 dissection lines of com...

  18. Effects of polysaccharides of ginseng (PSG) on haemopoietic stem, progenitor cells and chromosome aberration of bone marrow cells in x-irradiated mice

    International Nuclear Information System (INIS)

    The effects of PSG injection before X-irradiation on haemopoietic stem, progenitor cells and chromosome aberration of bone marrow cells in mice were investigated. The results showed that the colonies of CFU-S and CFU-GM in PSG group were significantly higher than that in the control group. The time courses of CFU-S and CFU-GM of bone marrow in the X-irradiated mice indicated that the effects still existed on the 7th day after irradiation with 3.0 Gy X-rays. Simultaneously, it was found that the rate of chromosome aberration or the rate of aberrated cells in PSG group was lower than that in the control group

  19. Yield of chromosomal aberrations and recoil particle range in Chineses hamster fibroblasts exposed to 8.5 to 500 keV neutrons

    International Nuclear Information System (INIS)

    Induction of chromatid aberrations in S-phase Chinese hamster fibroblasts has been studied for irradiation by 60Co gamma rays and neutrons of average energy 8.5, 45, 83, 200 and 500 keV. At 10 per cent aberration level the relative biological afficiency varied between 2.2 +- 0.6 (at 8.5 keV) and a maximum of 47 +- 9 (at 200 keV). The neutron generated recoils have short range in comparison to chromosomal dimensions. The strong variation with neutron energy is therefore not necessarily reflecting variations in the average linear energy transfer. Good agreement between experimental and predicted response was obtained when effects ascribed to range were considered. A critical volume within which primary lesions should occur in order to make chromosomal aberrations probable was derived. The corresponding site radius was estimated to be 1-3 μm. (author)

  20. Dose response relationship for unstable-type chromosome aberration rate of spleen cells from mice continuously exposed to low-dose-rate gamma-rays

    International Nuclear Information System (INIS)

    It has been reported that people who are chronically exposed to radiation such as nuclear facility workers and medical radiologists have slightly higher incidences of chromosome aberrations than non-exposed people. However, chronological changes of chromosome aberration rates related to accumulated doses and dose-rates for low dose-rate radiation exposures have not been well studied. Precise analyses of human populations are quite limited because confounding factors influence the results. For this reason, animal experiments are important for analyses. Mice were continuously exposed to gamma-rays at 400 mGy/22 hr/day for 10 days, 20 mGy/22 hr/day for about 400 days, and 1 mGy/22 hr/day for about 615 days under SPF conditions. Chronological changes of unstable-type chromosome aberration rates of spleen cells were observed along with accumulated doses at the middle dose rate and the two low-dose rates by conventional Giemsa-staining method. Aberrations such as dicentric chromosome, ring chromosome and fragment increased in a two-phase manner within 0-1.2 Gy and 2-8 Gy at 20 mGy/22 hr/day. They slightly increased up to 0.5 Gy at 1 mGy/22 hr/day. Aberration rates for 1, 2, 8 Gy at the 20 mGy/22 hr/day and for 0.5 Gy at 1 mGy/22 hr/day were 5.1, 9.6, 13.9 and 2.2 times higher than those of age-matched, non-irradiated control mice, respectively. Chromosome aberration rates at 400 mGy/22 hr/day were 2.7 times higher than that of 20 mGy/22 hr/day for the same total dose of 1.2 Gy. The results that unstable-type chromosome aberrations increased with accumulated dose of the low-dose rate radiation will be important to establish biological dosimetry for people who are chronically exposed to radiation. (author)

  1. Neocarzinostatin-induced Rad51 nuclear focus formation is cell cycle regulated and aberrant in AT cells

    International Nuclear Information System (INIS)

    DNA double-stranded breaks are the most detrimental form of DNA damage and, if not repaired properly, may lead to an accumulation of chromosomal aberrations and eventually tumorigenesis. Proteins of the Rad51/Rad52 epitasis group are crucial for the recombinational repair of DNA double-stranded breaks, whereas the Rad50/NBS1/Mre11 nuclease complex is involved in both the recombinational and the end-joining repair of DNA double-stranded breaks. Herein, we demonstrate that the chemotherapeutic enediyne antibiotic neocarzinostatin induced Rad51, but not NBS1, nuclear focus formation in a cell- cycle-dependent manner. Furthermore, neocarzinostatin-induced Rad51 foci formation revealed a slower kinetic change in AT cells, but not in wild-type or NBS cells. In summary, our results suggest that neocarzinostatin induces Rad51 focus formation through an ATM- and cell-cycle-dependent, but NBS1-independent, pathway

  2. A study on the chromosomal aberration in T. astivum VAR.CHUANFU No.1 to No.4 and 4037

    International Nuclear Information System (INIS)

    Wheat variety Chuanfu No.1 had been bred from Chuanyu No.5 by 32P induction. Chuanfu No.2 to No.4 and 4037 had been bred by 60Co γ ray induction. The chromosome constitution changed a little with Chuanfu No.1 compared with Mianyang 19. There were differences with one pair of chromosomes between Chuanfu No.2 and Chuanfu No.1 and between Chuanfu No.2 and Mianyang 19. In the hybrid F1 of 4037 and Mianyang 19 one quadrivalents formed in many meiosis. In the hybrid F1 or Chuanfu No.2 and 4037, one qudrivalent, one trivalent, 2 univalent or 4 univalent formed in different meiosis. 4037 was a strain of translocation. Several chromosomes changed among 2882 and several varieties. The powdery mildew resistance of 4037 was controlled by one gene which showed additive effect and was induced by 60Co γ-ray

  3. Biophysical modelling of radiation induced damage in chromosomes

    International Nuclear Information System (INIS)

    A computational biophysical model is described which simulates radiation damage to human blood lymphocytes by photon and electron radiation. The model includes a realistic simulation of the geometrical structure of lymphocytes (plasma, nucleus, chromatin, DNA) and its chemical constituents. The simulation of damage to DNA, which is the critical target for the induction of chromosome aberrations, takes into account direct effects (energy deposition) and indirect effects (radical attack). Furthermore, an attempt has been made to correlate DNA damage within the cell nucleus to the coefficients of the dose effect relationships for the induction of dicentric chromosomes; reasonable agreement is found with relevant experimental data. (author)

  4. Estimation of X ray overexposure in a childhood leukaemia cluster by means of chromosome aberration analysis

    International Nuclear Information System (INIS)

    Only multiple X ray diagnostics could be identified as a common risk factor in a leukaemia cluster that appeared between 1985-1989 in the municipality of Sittensen in northern Germany. In order to judge if the effect could be explained by irradiation dose, estimates were done in two of the leukaemia cases and seven former patients of a practice where some of the leukaemia cases had been treated for orthopaedic reasons. The methods used for the reconstruction of doses were physical simulation and biological dosimetry by dicentric chromosomes in peripheral lymphocytes. Compared to the Bremen laboratory control the mean frequency of dicentric chromosomes in the lymphocytes of the seven volunteers was significantly elevated. An overexposure of about 12-fold could be derived compared to state of the art X raying. At least two cases of the leukaemia cluster in Sittensen can therefore be correlated to an overexposure by diagnostic X rays. (author)

  5. Influence of acute irradiation on induction of chromosome aberrations in cultured cells of the fish Ameca splendens

    International Nuclear Information System (INIS)

    There is very little published information on the genetic and cytogenetic responses of fish to radiation. Since a large proportion of the low-level waste arising from the nuclear power industry is discharged to aquatic environments, this constitutes a significant deficiency in our knowledge. While it is not expected that fish populations are seriously at risk, confirmatory evidence would be useful and would also provide a basis for generalizations from the much greater body of information available for mammalian systems. A primary cell culture has been obtained from pooled embryonic tissue of the small tropical fish Ameca splendens. This material has two advantages from the point of view of cytogenetic studies: the diploid chromosome complement is 26, and the chromosomes are all fairly large and most have a well defined centromere. The spectrum of aberrations found in these cells after irradiation with 60Co γ rays is similar to that found in irradiated mammalian cells in culture, and an acute dose-response curve has been obtained. (author)

  6. Development of a two-parameter slit-scan flow cytometer for screening of normal and aberrant chromosomes: application to a karyotype of Sus scrofa domestica (pig)

    Science.gov (United States)

    Hausmann, Michael; Doelle, Juergen; Arnold, Armin; Stepanow, Boris; Wickert, Burkhard; Boscher, Jeannine; Popescu, Paul C.; Cremer, Christoph

    1992-07-01

    Laser fluorescence activated slit-scan flow cytometry offers an approach to a fast, quantitative characterization of chromosomes due to morphological features. It can be applied for screening of chromosomal abnormalities. We give a preliminary report on the development of the Heidelberg slit-scan flow cytometer. Time-resolved measurement of the fluorescence intensity along the chromosome axis can be registered simultaneously for two parameters when the chromosome axis can be registered simultaneously for two parameters when the chromosome passes perpendicularly through a narrowly focused laser beam combined by a detection slit in the image plane. So far automated data analysis has been performed off-line on a PC. In its final performance, the Heidelberg slit-scan flow cytometer will achieve on-line data analysis that allows an electro-acoustical sorting of chromosomes of interest. Interest is high in the agriculture field to study chromosome aberrations that influence the size of litters in pig (Sus scrofa domestica) breeding. Slit-scan measurements have been performed to characterize chromosomes of pigs; we present results for chromosome 1 and a translocation chromosome 6/15.

  7. Observation on the Frequency of Chromosomal Aberration and Changes in Number of Peripheral Lymphocytes in Radioactive Iodine Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Chun Hee; Shin, Min Ho; Park, Young Ju; Lee, Jung Yim; Park, Tae Yong; Lee, Jae Yong; Kim, Chong Soon; Han, Seung Soo; Kim, Kwang Hoe [Hanil General Hospital, Seoul (Korea, Republic of); Kim, Hee Gun; Kang, Duck Won; Song, Myung Jae [Korean Electric Power Corporation Research-Development Center, Daejeon (Korea, Republic of)

    1995-06-15

    For biological dosimetry of radiation exposure, both observing hematologic change and calculating Ydr by chromosomal analysis as biological indicators are widely used. However, due to the lack of studies on biological dosimetry of radiation dose absorbed in the body such as in the cases of radioactive iodine therapy, the maximal and safe dose is not well known, nor is the extent to which the body can safely endure radiation exposure. To investigate the practical applicability of hematologic changes and Ydr as an indicator for estimating radiation exposure, to patients with thyroid diseases after doses of radioactive iodine. 5 patients with hyperthyroidism and 35 patients who have had thyroid cancer operation were under treatment with radioactive iodine, changes in number of lymphocytes were tracked and Ydr was calculated for more than 2 months by chromosomal analysis in peripheral lymphocytes. 1) The number of lymphocytes began to decrease 2 weeks after doses of radioactive iodine, and reached the nadir after 6 and 8 weeks, then gradually recovered. 2) The nadir count of lymphocytes was reversely correlated with the administered dosage of radioactive iodine. 3) Ydr was generally stable between 2 and 8 weeks. 4) The maximal value of Ydr was correlated with the administered dosage of radioactive iodine. 5) Ydr value at the 2nd week increased with augmented dosage of radioactive iodine. 6) Ydr value at the 2nd week was correlated with fall of lymphocyte count. Patients must be closely observed, because temporary bone marrow suppression and slight chromosomal aberration can be produced by even generally used dosages of radioactive iodine for diagnosis and therapy. Maximal percent fall of lymphocyte count, Ydr at the 2 week interval and maximal Ydr can be used as the biological predictor of administered dosage of radioactive iodine.

  8. Interspecific comparisons of the sensitivity to chromosome aberration production by x rays

    International Nuclear Information System (INIS)

    It is concluded that arm number probably plays a minor role, if any, in the relative radiosensitivity of a species. Instead the reported differences are probably a reflection of inherent basic biological mechanisms of repair that vary from one order of mammals to the next. It should be added, however, that the ultimate goal of all of these studies is to make a reasonable risk estimate for man. In that context the best approach is that of conservatism and the current data on mouse and man suggest that man has 1.5 to 2.0 times the risk of mice for chromosome rearrangement induction by x rays

  9. Mouse Lymphoblastic Leukemias Induced by Aberrant Prdm14 Expression Demonstrate Widespread Copy Number Alterations Also Found in Human ALL

    International Nuclear Information System (INIS)

    Aberrant expression and activation of oncogenes in somatic cells has been associated with cancer initiation. Required for reacquisition of pluripotency in the developing germ cell, PRDM14 initiates lymphoblastic leukemia when misexpressed in murine bone marrow. Activation of pluripotency in somatic cells can lead to aneuploidy and copy number alterations during iPS cell generation, and we hypothesized that PRDM14-induced lymphoblastic leukemias would demonstrate significant chromosomal damage. High-resolution oligo array comparative genomic hybridization demonstrated infrequent aneuploidy but frequent amplification and deletion, with amplifications occurring in a 5:1 ratio with deletions. Many deletions (i.e., Cdkn2a, Ebf1, Pax5, Ikzf1) involved B-cell development genes and tumor suppressor genes, recapitulating deletions occurring in human leukemia. Pathways opposing senescence were frequently deactivated via Cdkn2a deletion or Tbx2 amplification, with corollary gene expression. Additionally, gene expression studies of abnormal pre-leukemic B-precursors showed downregulation of genes involved in chromosomal stability (i.e., Xrcc6) and failure to upregulate DNA repair pathways. We propose a model of leukemogenesis, triggered by pluripotency genes like Prdm14, which involves ongoing DNA damage and failure to activate non-homologous end-joining secondary to aberrant gene expression

  10. Loss of centromeric histone H2AT120 phosphorylation accompanies somatic chromosomes inactivation in the aberrant spermatocytes of Acricotopus lucidus (Diptera, Chironomidae).

    Science.gov (United States)

    Staiber, Wolfgang

    2016-01-01

    In the germ line of the chironomid Acricotopus lucidus, two cells with quite different chromosome constitutions result from the last unequal gonial mitosis. In the male, the future primary spermatocyte receives all the germ line-limited chromosomes (=Ks) together with somatic chromosomes (=Ss), and later on undergoes meiotic divisions, while the connected aberrant spermatocyte gets only Ss and remains undivided with chromosomes inactivated in a metaphase-like condensed state. This raises the question whether the centromeres of the permanently condensed Ss of the aberrant spermatocyte remain active during meiosis of the connected regular spermatocyte. Active centromeres exhibit an epigenetic phosphorylation mark at threonine 120 of histone H2A. To visualise the centromeric H2A phosphorylation of the Ss in the aberrant spermatocyte, meiotic stages were immunostained with different anti-phospho histone H2AT120 antibodies. Clear H2AT120ph signals appear at the centromeres of the Ss during prophase, persist on the metaphase-like condensed Ss during meiosis I of the connected primary spermatocyte and disappear during transition to meiosis II. The centromeres of the Ss and Ks of the regular spermatocytes display H2AT120ph signals from prophase I to anaphase II. The loss of the H2AT120 phosphorylation detected on the centromeres of the Ss of the aberrant spermatocyte indicating their deactivation supports the idea of a programmed inactivation of the Ss to block the entry of the germ line-derived aberrant spermatocyte, lacking Ks, into meiosis, and thus to prevent the generation of sperms possessing only Ss. This mechanism would ensure the presence of the Ks in the germ line. PMID:25820679

  11. Prevalence of the 14/20 centric fusion chromosomal aberration in US Simmental cattle.

    Science.gov (United States)

    Weber, A F; Buoen, L C; Zhang, T; Ruth, G R

    1992-05-01

    Cytogenetic evaluation was made on 353 Simmental cattle (166 male, 187 female) from 113 herds in 26 states. One hundred thirty-eight (39%) were found to be heterozygous-positive for the 14/20 centric fusion chromosomal translocation, including 41 (25%) males and 97 (52%) females. One submitted heparinized blood sample from a Simbrah bull was found to be positive for 14/20 and 1/29 centric fusions. Sampling, which was based on requests, was highly selective. Thus, the 39% prevalence found was not representative of 14/20 centric fusion in the national Simmental breed. On the basis of our findings, cytogenetic evaluation of breeding stock was consistent with modern management practice. PMID:1601712

  12. Radioprotective effects of histamine H2 receptor antagonists famotidine and ranitidine on gamma ray induced chromosome damage

    International Nuclear Information System (INIS)

    Histamine H2 receptor antagonist such as Cimetidine, Famotidine and Ranitidine are used in the clinical treatment of peptic ulcer. In vitro metaphase analysis and micronucleus assay were used to test the effects of famotidine and ranitidine on Cobalt 60 γ-ray induced clastogenic effects. Heparinised whole blood was obtained from healthy non-smoker volunteers. Blood samples were irradiated at a dose of 3Gy and incubated at 37 deg C for 1h. Lymphocyte cultures were initiated for metaphase chromosomes and cytochalasin B blocked micronucleus analysis. Aqueous solution of Famotidine (150 g/ml) and Ranitidine (500 g/ml) was added to the whole blood cultures at 0h and 24h. Cultures were harvested and processed at 48h and 72h for chromosome aberrations and micronucleus analysis respectively. Cultures treated with Famotidine at 0h and 24h after 3Gy γ-ray irradiation induce 60.90% and 56.52% inhibition in dicentrics, 48.70% and 43.61% inhibition in total aberrations. Ranitidine at 0h and 24h after 3Gy γ-ray irradiation induce 52.17% and 43.47% inhibition in dicentrics, 33.60% and 46.15% inhibition in total aberrations, when compared with 3Gy γ-ray irradiation alone. 43-54% inhibition in Binucleated cells with micronuclei and 47.72% inhibition in micronuclei at 0h treatment respectively. In conclusion radioprotective effects of Histamine H2 receptor antagonists famotidine and ranitidine on γ-ray induced chromosome damage is observed and the drugs effectively reduced the frequency of radiation induced chromosome aberrations and micronucleus. Famotidine was found to be more effective. The mechanism in which these drugs reduce clastogenic effect of γ-radiation is not fully understood. It might be due to their antioxidant and free radical-scavenging properties. (author)

  13. The induction by ionizing radiation of chromosomal aberrations in rhesus monkey pre-meiotic germ cells

    International Nuclear Information System (INIS)

    The induction of reciprocal translocations in rhesus monkey stem-cell spermatogonia was studied using multivalent analysis at metaphase of primary spermatocytes. Animals were exposed to 1 Gy γ-rays at dose rates of 140 and 0.2 mGy/min or to 0.25 Gy acute 2 MeV neutrons. Reduction of the dose from 140 mGy/min to 0.2 mGy/min did not result in a lowering of the frequencies of recovered translocations of 0.43 %. The neutron data indicated an RBE (neutrons vs. X-rays) of 2.1, which is clearly lower than the value of 4 obtained in the mouse. It is made plausible that in general mammalian species with high sensitivities for the cytotoxic effects of ionizing radiation, such as the rhesus monkey, will exhibit relatively high threshold dose rates below which no further reduction in aberration yield occurs, whereas in more resistant species, such as the mouse, the threshold dose rate will be at a very low level. Similarly, resistant species will show relatively high RBNE values for neutron irradiation and sensitive species low ones. (author). 36 refs.; 2 tabs

  14. The effects of oxygen and hypoxic cell sensitizers on chromosome aberration induction in human lymphocytes

    International Nuclear Information System (INIS)

    Normal human blood was exposed at 370C to 250 kVp X-rays under conditions of anoxia and of equilibration with oxygen. The numbers of observed dicentric aberrations were fitted to the expression Y = αD + βD2 and from these curves an OER estimate of 2.8 at 5.0 Gy was obtained. The dicentric yield was also measured after blood held at various oxygen tensions was exposed to 3.0 Gy or 0.75 Gy X-rays. No difference was observed between the values at the lowest oxygen concentration of less than 2 ppm and at 250 ppm. Above 250 ppm there was a steep rise in the number of dicentrics observed but at oxygen levels above 1% the dicentric yield was again much less dependent on the oxygen concentration. The experiments were repeated using different concentrations of 'Flagyl' and Ro 07 0582 which both showed a maximum effect at 4 to 8 mM. Dose response data obtained in the presence of 8 mM sensitizer were again fitted to the quadratic expression and enhancement ratios of 2.2 and 1.4 estimated for Ro 07 0582 and 'Flagyl' respectively. Blood irradiated at venous oxygen tension in the presence of each of these chemicals showed an unchanged dicentric yield in the case of 'Flagyl' and a slight increase with Ro 07 0582 at a dose of 1.0 Gy. (Auth.)

  15. Electron Vortex Production and Control Using Aberration Induced Diffraction Catastrophes

    Science.gov (United States)

    Petersen, T. C.; Weyland, M.; Paganin, D. M.; Simula, T. P.; Eastwood, S. A.; Morgan, M. J.

    2013-01-01

    An aberration corrected electron microscope is used to create electron diffraction catastrophes, containing arrays of intensity zeros threading vortex cores. Vortices are ascribed to these arrays using catastrophe theory, scalar diffraction integrals, and experimentally retrieved phase maps. From measured wave function phases, obtained using focal-series phase retrieval, the orbital angular momentum density is mapped for highly astigmatic electron probes. We observe vortex rings and topological reconnections of nodal lines by tracking the vortex cores using the retrieved phases.

  16. Alignment induced aberration fields of next generation telescopes

    Science.gov (United States)

    Schmid, Tobias; Thompson, Kevin; Rolland, Jannick

    2008-08-01

    There is a long list of new ground-based optical telescopes being considered around the world. While many are conventional Cassegrain and Ritchey-Chretien designs, some are from a family of three mirror anastigmatic (TMA) telescopes that are configured with an offset field (but still obscured) that trace back to designs developed in the 1970s for military applications. The nodal theory of aberrations, developed in the late 1970s, provides valuable insights into the response of TMA telescopes to alignment errors. Here it is shown for the first time that the alignment limiting aberration in any TMA telescope is a 3rd order astigmatism term with a new field dependence, termed field-asymmetric, field-linear 3rd order astigmatism. It is also shown that a TMA telescope under assembly that is only measured to have excellent/perfect performance onaxis is not aligned in any significant way. This is because the new astigmatic term is always zero on-axis, even though it is large over the field of view. Knowledge of this intrinsic misalignment aberration field for any TMA telescope aids greatly in ensuring it can be aligned successfully. The James Webb Space Telescope (JWST), is used an example of a relevant TMA system.

  17. Assessment of chromosomal aberration in the bone marrow cells of Swiss Albino mice treated by 4-methylimidazole.

    Science.gov (United States)

    Norizadeh Tazehkand, Mostafa; Topaktas, Mehmet; Yilmaz, Mehmet Bertan

    2016-07-01

    4-Methylimidazole (4-MEI) is formed during the production of certain caramel coloring agents used in many food and drink products. It may also be formed during the cooking, roasting, or other processing of some foods and beverages. So it was unintentionally consumed in worldwide. This study was aimed to investigate the genotoxic and cytotoxic effects of 4-MEI using chromosome aberration (CA) and mitotic index (MI) in Swiss Albino mice. In this research, CA and MI of the mouse bone marrow cells were analyzed after treating the animals with 4-MEI (100, 130 and 160 mg/kg) for 12 h and 24 h treatment times. All data were analyzed using statistical methods. 4-MEI significantly increased the percentage of CAs at all concentrations for 12 h and at highest concentration for 24 h treatment periods. 4-MEI at highest concentration for 12 h and at all concentrations for 24 h decreased the MI in comparison with control. Genotoxic and cytotoxic effects of 4-MEI at 24 h treatment periods were concentration dependent. Consequently, it can be said that 4-MEI have genotoxic and cytotoxic effect in mouse. PMID:26634952

  18. Non-Target Effect for Chromosome Aberrations in Human Lymphocytes and Fibroblasts After Exposure to Very Low Doses of High LET Radiation

    Science.gov (United States)

    Hada, Megumi; George, Kerry A.; Cucinotta, F. A.

    2011-01-01

    The relationship between biological effects and low doses of absorbed radiation is still uncertain, especially for high LET radiation exposure. Estimates of risks from low-dose and low-dose-rates are often extrapolated using data from Japanese atomic bomb survivor with either linear or linear quadratic models of fit. In this study, chromosome aberrations were measured in human peripheral blood lymphocytes and normal skin fibroblasts cells after exposure to very low dose (.01 - 0.2 Gy) of 170 MeV/u Si-28-ions or 600 MeV/u Fe-56-ions. Chromosomes were analyzed using the whole chromosome fluorescence in situ hybridization (FISH) technique during the first cell division after irradiation, and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving >2 breaks in 2 or more chromosomes). The curves for doses above 0.1 Gy were more than one ion traverses a cell showed linear dose responses. However, for doses less than 0.1 Gy, Si-28-ions showed no dose response, suggesting a non-targeted effect when less than one ion traversal occurs. Additional findings for Fe-56 will be discussed.

  19. Dose-effect relationship between premature chromosome induced by Calyculin A and low-dose ionizing radiation

    International Nuclear Information System (INIS)

    Objective: To explore the feasibility of Calyculin A induced premature chromosome condensation to be used as a biodosimetry of low-dose ionizing radiation. Methods: Peripheral blood was drawn from healthy adults and Anticoagulated with Heparin. a set of tubes was irradiated by X-ray. The irradiation dose included 0, 0.1, 0.25, 0.5, 0.75, 1.0 Gy. After irradiation, the whole blood was added to each PRMI1640 medium, All incubations were Cultured for up to 48 h at 37 degree C in an atmosphere of 5% CO2 in air. Colcemid was added 24 hours after cultures start and Calyculin A was added for the last 2 hours to induce PCC. The chromosome spreads were prepared, stained with Giemsa and observed under a microscope. The dose-response relationship of the total aberration, fragment, dicentric + centric ring (dic + r) in the irradiated lymphocytes was examined. Results: The PCC was successfully induced in lymphocytes with Calyculin A. the yield of chromosome aberrations increased with the dose going up. An quadratic polynomial dose response model was fitted. Conclusion: Premature chromosome condensation induced by Calyculin A can be used as a technology to estimate the radiation dosage of low-dose ionizing radiation, but still need more data to improve. (authors)

  20. The ability of two cooked food mutagens to induce aberrant crypt foci in mice

    DEFF Research Database (Denmark)

    Kristiansen, E.; Meyer, Otto A.; Thorup, I.

    1997-01-01

    azoxymethane (AOM) (5 mg/kg body weight) and 1,2-dimethylhydrazine dihydrochloride (DMH-2HCI) (20 mg/kg body weight), respectively, one dose a week for two weeks, Animals were killed after four and 10 weeks, After four weeks only the mice dosed with IQ and PhIP had aberrant crypt foci, A much higher number of...... induced a higher percentage of medium or large sized aberrant crypt foci than PhIP or IQ, The interpretation of the aberrant crypt foci as precursor lesions for colon cancer in the PhIP and IQ mice is difficult because PhIP and IQ have not been reported to be colonic carcinogens, If cooked food mutagens...... such as IQ or PhIP are to be used as initiators in the aberrant crypt foci test, the use of rats may be preferable....

  1. Cytogenetic findings in adult secondary acute myeloid leukemia (AML): frequency of favorable and adverse chromosomal aberrations do not differ from adult de novo AML

    DEFF Research Database (Denmark)

    Preiss, Birgitte S; Bergman, Olav J; Friis, Lone S; Sørensen, Anne; Frederiksen, Michael; Gadeberg, Ole V; Mourits-Andersen, Torben; Østergaard, Birthe; Kerndrup, Gitte B

    2010-01-01

    by treatment with chemotherapy and/or irradiation (t-AML). Cytogenetic analysis was carried out in 93%, of which 61% had clonal chromosome aberrations. MDS-AML correlated to a normal karyotype (P <0.001). t-AML correlated to abnormal clones with numerical and structural aberrations (P = 0.03), five...... or more unrelated aberrations (P = 0.03), marker chromosomes (P = 0.006), abnormal mitoses only (P = 0.01), female sex (P <0.001), and -7 (P = 0.006). Centromeric breakage correlated to a complex karyotype (P = 0.01). The frequencies of aberrations in s-AML patients were compared with an age......-matched group of de novo AML patients diagnosed in the same area and period. In this comparison, s-AML only correlated to -7 (P = 0.02). In 42 patients, we found that MDS patients with an abnormal karyotype were more likely to show cytogenetic evolution during progression to AML than MDS patients with a normal...

  2. Radio Protective Effects of Ginseng Extract in Gamma-Rays Induced Chromosomal Damages of Human Lymphocyte

    Directory of Open Access Journals (Sweden)

    M. Syaifudin

    2008-01-01

    Full Text Available Ginsan, a polysaccharide extracted from Panax ginseng and subsequently referred as ginseng, posses various biological properties as an anticancer and antioxidant agent. Ginseng also approved effective against radiation effects through its immunomodulating actions in whole body irradiated mouse. But its protective effects on radiation induced DNA damage are not thoroughly investigated, mainly in human. This experiment aimed to assess the effects of ginseng at 2 working doses in suppressing radiation effects of human peripheral blood lymphocyte (PBL i.e. chromosome aberration and micronuclei yields. The treatment times were 24 hours before, subsequently (0 hour or 3 hours after and irradiation with gamma rays at doses of 0.5 - 2.0 Gy (dose rate of 3.16 Gy/min. Treated and untreated blood cultivation and metaphase spreading technique was done according to standard procedures. Results showed that without ginseng treatments, radiation significantly increased dicentrics and micronuclei frequencies. Different with the results in mouse study, however, our results indicated that none of the experimental concentrations of ginseng crude water extract tested had an effect on baseline chromosomal aberration and micronuclei (MN yields in PBL. A protective effect was only seen in chromosome aberration yields of sample irradiated with 2.0 Gy and treated with ginseng 3 h post irradiation rather than 24 h pre-irradiation in one volunteer. Opposite results that ginseng suspected to be a weak radiosensitizer was found in some cases. This may be due to discrepancies exist in route of treatment and its fundamental mechanisms of protective action between both studies. Even though in general it was not effective, the possible mechanism involved in radioprotective influence of ginseng is discussed.

  3. Radio Protective Effects of Ginseng Extract in Gamma-rays Induced Chromosomal Damages of Human Lymphocyte

    International Nuclear Information System (INIS)

    Ginsan, a polysaccharide extracted from Panax ginseng and subsequently referred as ginseng, posses various biological properties as an anticancer and antioxidant agent. Ginseng also approved effective against radiation effects through its immunomodulating actions in whole body irradiated mouse. But its protective effects on radiation induced DNA damage are not thoroughly investigated, mainly in human. This experiment aimed to assess the effects of ginseng at 2 working doses in suppressing radiation effects of human peripheral blood lymphocyte (PBL) i.e. chromosome aberration and micronuclei yields. The treatment times were 24 hours before, subsequently (0 hour) or 3 hours after and irradiation with gamma rays at doses of 0.5 - 2.0 Gy (dose rate of 3.16 Gy/min). Treated and untreated blood cultivation and metaphase spreading technique was done according to standard procedures. Results showed that without ginseng treatments, radiation significantly increased dicentrics and micronuclei frequencies. Different with the results in mouse study, however, our results indicated that none of the experimental concentrations of ginseng crude water extract tested had an effect on baseline chromosomal aberration and micronuclei (MN) yields in PBL. A protective effect was only seen in chromosome aberration yields of sample irradiated with 2.0 Gy and treated with ginseng 3 h post irradiation rather than 24 h pre-irradiation in one volunteer. Opposite results that ginseng suspected to be a weak radiosensitizer was found in some cases. This may be due to discrepancies exist in route of treatment and its fundamental mechanisms of protective action between both studies. Even though in general it was not effective, the possible mechanism involved in radioprotective influence of ginseng is discussed. (author)

  4. The frequency of chromosomal aberrations in sheep from the area contaminated by depleted uranium during NATO air strikes in 1999

    Directory of Open Access Journals (Sweden)

    Fišter Svetlana L.

    2014-01-01

    Full Text Available This paper presents the results of cytogenetic studies in sheep from the region of Bujanovac that was contaminated by depleted uranium during the NATO air strikes in 1999. The study was conducted on sheep blood lymphocytes, in order to determine the frequency of chromosomal aberrations and to assess the presence of genetic risk as a result of the possible impact of depleted uranium. Blood samples for lymphocyte cultures were taken at random from the 20 animals of the households in the village of Borovac, near Bujanovac. The animals were chosen because they were pastured, fed, and watered in the NATO bombing area. With the purpose of comparing the results two control groups were cytogenetically analyzed, each consisted of 20 sheep from Zemun and Ovča, two northern localities that were not contaminated with depleted uranium. The established structural chromosomal changes were of breaks and gap types, and their frequencies in sheep of all surveyed localities were within the range of basic level values that are commonly found in the sheep lymphocyte cultures analyses. Significant differences are apparent between the values defined in the sheep from Bujanovac compared to those obtained in the sheep from the northern locality (Zemun, probably as a result of breeding of animals in the farm conditions and their being less exposed to the impact of environmental agents. There were neither elevated values of polyploid and aneuploid cells nor significant differences between the sites. According to earlier known data, depleted uranium was below the detection limit of the method applied both in the soil and feed given to cytogenetically analyzed animals. Based on the low-level changes that are in the range of the basic level changes, commonly observed in sheep lymphocytes control cultures, it cannot be said with certainty that it was depleted uranium that caused the changes, or that it is wide-spread in the region of Bujanovac. [Projekat Ministarstva nauke

  5. The rejoining of x-ray-induced breaks in human interphase chromosomes from normal and ataxia cells

    International Nuclear Information System (INIS)

    Patients with the genetically inherited recessive disease ataxia telangiectasia (AT), in addition to various clinical disorders including cancer proneness, are extremely sensitive to the lethal effects of ionizing radiations. Following irradiation, cells cultured from such individuals show greatly enhanced cell killing, and marked increase in the production of chromosomal aberrations. Consequently, it has been proposed that AT cells are deficient in the repair of radiation-induced damage to DNA, yet it has not been possible to demonstrate the nature of this deficiency at the molecular level. The authors have measured the rejoining rates of x-ray-induced breakage in the interphase chromosomes of normal human, and AT fibroblasts by means of premature chromosome condensation (PCC). Results show that neither the level of initially sustained x-ray damage, nor the rate at which PCC fragments rejoin, are significantly different between the two cell types. However, an appreciably larger fraction of breaks failed to rejoin in ataxia cells

  6. Induction of chromosome aberration in human lymphocytes and its dependence on X ray energy

    International Nuclear Information System (INIS)

    The variations of dose response with X ray energy observed with the human lymphocyte dicentric assay is examined. In order to determine reliably the initial slopes (RBEm) many cells need to be analysed at low doses. Insufficient analysis may explain some reported interlaboratory differences in fitted dose-response coefficients. One such discrepancy at 150 kVp, E(mean) = 70 keV is examined. Data are also presented for an X ray spectrum of 80 kVp, E(mean) = 58 keV. Over the photon energy range 20 keV X rays to 1.25 MeV gamma rays RBEm varies by about a factor of 5, with the lower energies being more effective. This is consistent with microdosimetric theory. By contrast, in radiological protection a radiation weighting factor of 1.0 is assumed for all photons when assessing the risk of inducing cancer at low doses. The measured variations of biological effect with photon energy have led to suggestions that the lower energies, as used for some diagnostic radiology, carry a greater risk per unit dose than is normally assumed by those involved in radiological protection. Interpretation of the data reported in this paper does not support this view. (author)

  7. Biological dosimetry of ionizing radiation by chromosomal aberration analysis; Dosimetria biologica de las radiaciones ionizantes mediante el analisis de aberraciones cromosomicas

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Castano, S.; Silva, A.; Navlet, J.

    1990-07-01

    Biological dosimetry consists of estimating absorbed doses for people exposed to radiation by mean biological methods. Several indicators used are based in haematological, biochemical, and cytogenetic data, although nowadays without doubt, the cytogenetic method is considered to be the most reliable. In this case, the study ol chromosomal aberrations, normally dicentric chromosomes, in peripheral lymphocytes can be related to absorbed dose through an experimental calibration curve. An experimental dose-response curve, using dicentric chromosomes analysis, X-rays at 300 kVp, 114 rad/min and temperature 37 degree celsius has been produced. Experimental data is fitted to model Y ={alpha} + {beta}{sub 1}D + {beta}{sub 2}D 2 , where Y is the number of dicentrics per cell and D the dose. The curve is compared with those produced elsewhere. (Author) 14 refs.

  8. Genotoxicity and mutagenicity of water contaminated with tannery effluents, as evaluated by the micronucleus test and comet assay using the fish Oreochromis niloticus and chromosome aberrations in onion root-tips

    Directory of Open Access Journals (Sweden)

    Silvia Tamie Matsumoto

    2006-01-01

    Full Text Available Cytotoxicity of metals is important because some metals are potential mutagens able to induce tumors in humans and experimental animals. Chromium can damage DNA in several ways, including DNA double strand breaks (DSBs which generate chromosomal aberrations, micronucleus formation, sister chromatid exchange, formation of DNA adducts and alterations in DNA replication and transcription. In our study, water samples from three sites in the Córrego dos Bagres stream in the Franca municipality of the Brazilian state of São Paulo were subjected to the comet assay and micronucleus test using erythrocytes from the fish Oreochromis niloticus. Nuclear abnormalities of the erythrocytes included blebbed, notched and lobed nuclei, probably due to genotoxic chromium compounds. The greatest comet assay damage occurred with water from a chromium-containing tannery effluent discharge site, supporting the hypothesis that chromium residues can be genotoxic. The mutagenicity of the water samples was assessed using the onion root-tip cell assay, the most frequent chromosomal abnormalities observed being: c-metaphases, stick chromosome, chromosome breaks and losses, bridged anaphases, multipolar anaphases, and micronucleated and binucleated cells. Onion root-tip cell mutagenicity was highest for water samples containing the highest levels of chromium.

  9. Frequency of chromosome aberration and dose/dose rate effects in the mouse exposed to long-term low dose radiation

    International Nuclear Information System (INIS)

    Authors have been conducting long term irradiation experiments in the mouse with the dose rate as low as unreported hitherto and have shown with highly sensitive methods to detect chromosomal aberration, that there is the positive dose rate effect under even such a condition, of which details are described herein. According to the definition of United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCER) (1993), the low dose rate is 137Cs-gamma-ray at the low dose rate of 1 or 20 mGy/22 h/day (total, 125-615 or 100-8000 mGy, respectively). Other groups received radiations of 0 Gy (non-irradiated, age-matched control), 200-8000 mGy at 200 mGy/22 h/day, 400-8000 mGy at 400 mGy/22 h/day, or 250-2000 mGy at 890 mGy/min. At the defined days after exposure, mice were sacrificed, their spleens were dissected out, splenic cells were cultured for 48 hr, and their chromosome specimens were prepared to be stained with Giemsa or FISH (fluorescence in situ hybridization). Dicentric (dic) and translocation chromosomal aberrations were found to increase even with the lowest total (accumulated) dose, where the frequency was significantly higher than that in control. Comparison of the regression slopes at each dose rate of the relation between dose and aberration revealed the difference dependent on the rate, thus demonstrating the presence of dose rate effect. Dose/dose rate effect factor (DDREF) calculated by authors' procedure (at 1000-100 mGy: DDREF=17.8-4.5 for dic by FISH; 24.5-5.2 for dic+ring chromosome by Giemsa) was thought important in the risk assessment of low dose radiation and also revealed a problem in International Commission on Radiological Protection (ICRP) (1991) calculation of the factor. (K.T.)

  10. Arsenic-induced Aurora-A activation contributes to chromosome instability and tumorigenesis

    Science.gov (United States)

    Wu, Chin-Han; Tseng, Ya-Shih; Yang, Chao-Chun; Kao, Yu-Ting; Sheu, Hamm-Ming; Liu, Hsiao-Sheng

    2013-11-01

    Arsenic may cause serious environmental pollution and is a serious industrial problem. Depending on the dosage, arsenic may trigger the cells undergoing either proliferation or apoptosis-related cell death. Because of lack of the proper animal model to study arsenic induced tumorigenesis, the accurate risk level of arsenic exposure has not been determined. Arsenic shows genotoxic effect on human beings who uptake water contaminated by arsenic. Chromosome aberration is frequently detected in arsenic exposure-related diseases and is associated with increased oxidative stress and decreased DNA repairing activity, but the underlying mechanism remains elusive. Aurora-A is a mitotic kinase, over-expression of Aurora-A leads to centrosome amplification, chromosomal instability and cell transformation. We revealed that Aurora-A is over-expressed in the skin and bladder cancer patients from blackfoot-disease endemic areas. Our cell line studies reveal that arsenic exposure between 0.5 μM and 1 μM for 2-7 days are able to induce Aurora-A expression and activation based on promoter activity, RNA and protein analysis. Aurora-A overexpression further increases the frequency of unsymmetrical chromosome segregation through centrosome amplification followed by cell population accumulated at S phase in immortalized keratinocyte (HaCaT) and uroepithelial cells (E7). Furthermore, Aurora-A over-expression was sustained for 1-4 weeks by chronic treatment of immortalized bladder and skin cells with NaAsO2. Aurora-A promoter methylation and gene amplification was not detected in the long-term arsenic treated E7 cells. Furthermore, the expression level of E2F1 transcription factor (E2F1) is increased in the presence of arsenic, and arsenic-related Aurora-A over-expression is transcriptionally regulated by E2F1. We further demonstrated that overexpression of Aurora-A and mutant Ha-ras or Aurora-A and mutant p53 may act additively to trigger arsenic-related bladder and skin cancer

  11. Dose-rate effects and chronological changes of chromosome aberration rates in spleen cells from mice that are chronically exposed to gamma-ray at low dose rates

    International Nuclear Information System (INIS)

    Dose-rate effects have not been examined in the low dose-rate regions of less than 60-600 mGy/h. Mice were chronically exposed to gamma-ray at 20 mGy/day (approximately 1 mGy/h) up to 700 days and at 1 mGy/day (approximately 0.05 mGy/h) for 500 days under SPF conditions. Chronological