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Sample records for comparative radiation genetics

  1. The comparative radiation genetics of humans and mice

    International Nuclear Information System (INIS)

    Neel, J.V.

    1990-01-01

    The attempt by geneticists to predict the genetic consequences for humans of exposure to ionizing radiation has arguably been one of the most serious social responsibilities they have faced in the past half century. Important for its own sake, this issue also serves as a prototype for the effort to evaluate the ultimate genetic impact on ourselves of other human perturbations of the environment in which our species functions. Recently the authors have been developing the thesis that according to the results of studies on the children of survivors of the atomic bombings, humans may not be as sensitive to the genetic effects of radiation as has been projected by various committees on the basis of data from the most commonly employed paradigm, the laboratory mouse. In this paper, the authors attempt as detailed a comparison as space permits of the findings on humans and mice, presenting the data in a fashion that will enable those who at certain critical points in the argument wish to make other assumptions, to do so. The authors argue that a reconsideration that includes all the data now available on mice brings the estimate of the doubling dose for mice into satisfactory agreement with the higher estimate based on humans

  2. Genetic effects of ionizing radiation

    International Nuclear Information System (INIS)

    Myers, D.K.; Childs, J.D.

    1980-01-01

    The genetic material in living organisms is susceptible to damage from a wide variety of causes including radiation exposure. Most of this damage is repaired by the organism; the residual damage and damage which is not correctly repaired can lead to genetic changes such as mutations. In lower organisms, most offspring carry an unaltered copy of the genetic information that was present in the parental organism, most of the genetic changes which do occur are not caused by natural background radiation, and the increase in frequency of genetic changes after irradiation at low-dose rates is directly proportional to total radiation dose. The same principles appear to be valid in mammals and other higher organisms. About 105 out of every 1000 humans born suffer from some genetic or partly-genetic condition requiring medical attention at some time. It has been estimated that approximately 1 person in every 2000 born carry a deleterious genetic mutation that was caused by the continued exposure of many generations of our ancestors to natural background radiation. On the same basis, it is predicted that the incidence of genetic diseases would be increased to 106 per 1000 in the children and grandchildren of radiation workers who were exposed to 1 rem per year commencing at age 18. However, there was no detectable change in the health and fitness of mice whose male ancestors were repeatedly exposed to high radiation doses up to 900 rem per generation. (auth)

  3. Genetic effects of ionising radiation

    International Nuclear Information System (INIS)

    Saunders, P.A.H.

    1991-12-01

    Ionizing radiation effects on the gem cells, which can result in genetic abnormalities, are described. The basic mechanisms of radiation interactions with chromosomes, or specifically DNA, which can result in radiation induced mutation are discussed. Methods of estimating genetic risks, and some values for quantitative risk estimates are given. (U.K.). 13 refs., 2 figs., 1 tab

  4. Genetic effects of ionising radiation

    International Nuclear Information System (INIS)

    Saunders, P.

    1981-01-01

    The mutagenic effects of ionising radiation on germ cells with resulting genetic abnormalities in subsequent generations, are considered. Having examined a simple model to explain the interaction of ionising radiation with genetic material and discussed its limitations, the methods whereby mutations are transmitted are discussed. Methods of estimating genetic risks and the results of such studies are examined. (U.K.)

  5. Genetic effects of radiation

    International Nuclear Information System (INIS)

    Selby, P.B.

    1977-01-01

    Many of the most important findings concerning the genetic effects of radiation have been obtained in the Biology Division of Oak Ridge National Laboratory. The paper focuses on some of the major discoveries made in the Biology Division and on a new method of research that assesses damage to the skeletons of mice whose fathers were irradiated. The results discussed have considerable influence upon estimates of genetic risk in humans from radiation, and an attempt is made to put the estimated amount of genetic damage caused by projected nuclear power development into its proper perspective

  6. Health risks (early, delayed and genetic) from the present radiation level

    International Nuclear Information System (INIS)

    Stranden, E.

    1981-01-01

    A general survey is given of the risks of early, delayed and genetic injuries from present radiation environment. Brief data is presented on some industrial and medical accidents. It is stated that in Norway there are 5-10 incidents per year in industrial radiography, none of which have led to radiation syndrome. Delayed radiation effects are discussed and figures quoted for risk due to mining, industrial and medical radiography and natural sources. Genetic effects are similarly discussed and genetically significant doses from similar sources are quoted. It is concluded that the health risk from the radiation environment is very small compared with other risks. (JIW)

  7. Comparative radiation genetics. What we learnt from our studies on Medaka germ cell mutagenesis

    International Nuclear Information System (INIS)

    Shima, Akihiro

    2004-01-01

    , together with AFLP markers, turned out to be available for detection of crossing over at meioses and eventually allowed us to produce the first genome-wide genetic linkage map of Medaka. Our data accumulated over the last 18 years seemed to have convinced people that molecular biology and genomics can be studied on Medaka and thus initiated the current Medaka Genome Project aiming at understanding of Medaka on the basis of genome information. Recently emerging comparative genomics of humans and Medaka would strengthen the rationale for comparative radiation genetic approach, which would be anticipated to eventually provide a case study valid for assessing radiation risk to non-human biota. (author)

  8. Genetics and ionizing radiations. 2. The genetic effects of ionizing radiations

    International Nuclear Information System (INIS)

    Dutrillaux, B.

    1980-01-01

    Ionizing radiations are the best known mutagenic agents. Their relative importance as compared to other mutagens cannot be determined. Experiments show that male germinal cells are more sensitive than female germinal cells. This sensitivity is determined by the cell phase at the time of agression. Acute X-exposure results in a mutation rate of about 1.7x10 -7 rad -1 per gamete and per gene in the male. This rate is lower in case of chronic exposure. Pathological effects will appear in the first (dominant genes, and unbalanced chromosomal anomalies) or n-th generation (recessive genes and balanced chromosomal rearrangements). Direct studies on humans have brought contradictory results. Only X or γ-emitters induce a true genetic risk, the other radiations being too little penetrating to reach the gonads. The doubling dose of the mutation rate is estimated at over 100 rad in males and over 1,000 rad in females. However, one cannot conclude that low doses are not harmless because their effects are difficult to demonstrate. The individual risk, that remains low, must be distinguished from the collective risk for which the safeguard of the quality of the genetic material of our species must remain our prime purpose [fr

  9. Genetic susceptibility to radiations. Which impact on medical practice

    International Nuclear Information System (INIS)

    Alapetite, C.; Cosset, J. M.; Bourguignon, M. H.; Masse, R.

    2000-01-01

    Recent progress especially in the field of gene identification and expression have raised more attention on genetic susceptibility to cancer possibly enhanced by radiation. Radiation therapists are mostly concerned by this question since hypersensitive patients may suffer from adverse effects in normal tissues following a standard radiation therapy and normally sensitive patients could benefit from higher doses of radiation for better treatment of their malignant tumors. Although only a small percentage of individuals are hypersensitive to radiation effects, all medical specialists using ionising radiation should be aware of this new progress in medical knowledge. The present paper reviews the main pathologies (diseases, syndromes ...) known or strongly suspected to be associated with a hypersensitivity to ionizing radiation. Then the main tests capable of detecting in advance such pathologies are analyzed and compared. Finally guidelines are provided, especially to the radiation therapists to limit the risk of severe complications (or even deaths) for this specific subset of patients suffering from a genetic disorder with a susceptibility to radiation

  10. Genetic susceptibility to radiation: which impact on medical practice?

    Energy Technology Data Exchange (ETDEWEB)

    Alapetite, C.; Cosset, J.M. [Institut Curie, Dept. de Radiotherapie, 75 - Paris (France); Bourguignon, M.H.; Masse, R. [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France)

    2001-07-01

    Recent progress especially in the field of gene identification and expression have raised more attention on genetic susceptibility to cancer possibly enhanced by radiations. Radiation therapists are mostly concerned by this question since hypersensitive patients may suffer from adverse effects in normal tissues following a standard radiation therapy and normally sensitive patients could benefit from higher doses of radiations for a better cure of their malignant tumors. Although only a small percentage of individuals are 'hypersensitive' to radiation effects, all medical specialists using ionising radiations should be aware of these new progress in medical knowledge. The present paper reviews the main pathologies (diseases, syndromes...) known or strongly suspected to be associated with a hypersensitivity to ionizing radiations. Then the main tests capable to detect in advance such pathologies are analyzed and compared. Finally guidelines are provided, especially to the radiation therapists to limit the risk of severe complications (or even deaths) for these specific subset of patients suffering from a genetic disorder with a susceptibility to radiations. (author)

  11. Genetic susceptibility to radiation: which impact on medical practice?

    International Nuclear Information System (INIS)

    Alapetite, C.; Cosset, J.M.; Bourguignon, M.H.; Masse, R.

    2001-01-01

    Recent progress especially in the field of gene identification and expression have raised more attention on genetic susceptibility to cancer possibly enhanced by radiations. Radiation therapists are mostly concerned by this question since hypersensitive patients may suffer from adverse effects in normal tissues following a standard radiation therapy and normally sensitive patients could benefit from higher doses of radiations for a better cure of their malignant tumors. Although only a small percentage of individuals are 'hypersensitive' to radiation effects, all medical specialists using ionising radiations should be aware of these new progress in medical knowledge. The present paper reviews the main pathologies (diseases, syndromes...) known or strongly suspected to be associated with a hypersensitivity to ionizing radiations. Then the main tests capable to detect in advance such pathologies are analyzed and compared. Finally guidelines are provided, especially to the radiation therapists to limit the risk of severe complications (or even deaths) for these specific subset of patients suffering from a genetic disorder with a susceptibility to radiations. (author)

  12. Genetic effects of low level radiation

    International Nuclear Information System (INIS)

    Sumner, D.

    1988-01-01

    The author outlines the evidence for genetic effects. The incidence of congenital abnormalities, stillbirths and child deaths has been examined in 70,000 pregnancies in Hiroshima and Nagasaki and compared with pregnancies in an unirradiated control group. No difference was detected in incidence of congenital abnormalities of stillbirths, but there was a small insignificant increase in child deaths when both parents were exposed. The number of children born with chromosome aberrations was slightly higher, but insignificant in the exposed group compared with controls. However, surveys of congenital malformations in children of radiologists and in children of Hanford workers suggest a genetic effect of radiation. Absolute and relative methods of calculating risks and the ICRP risk factor is also briefly discussed. (U.K.)

  13. Genetic risks from radiation

    International Nuclear Information System (INIS)

    Selby, P.B.

    Two widely-recognized committees, UNSCEAR and BEIR, have reevaluated their estimates of genetic risks from radiation. Their estimates for gene mutations are based on two different approaches, one being the doubling-dose approach and the other being a new direct approach based on an empirical determination of the amount of dominant induced damage in the skeletons of mice in the first generation following irradiation. The estimates made by these committees are in reasonably good agreement and suggest that the genetic risks from present exposures resultng from nuclear power production are small. There is room for much improvement in the reliability of the risk estimates. The relatively new approach of measuring the amount of induced damage to the mouse skeleton shows great promise of improving knowledge about how changes in the mutation frequency affect the incidence of genetic disorders. Such findings may have considerable influence on genetic risk estimates for radiation and on the development of risk estimates for other less-well-understood environmental mutagens. (author)

  14. The genetics of radiation-induced osteosarcoma

    International Nuclear Information System (INIS)

    Rosemann, M.; Kuosaite, V.; Nathrath, M.; Atkinson, M.J.

    2002-01-01

    Individual genetic variation can influence susceptibility to the carcinogenic effects of many environmental carcinogens. In radiation-exposed populations those individuals with a greater genetically determined susceptibility would be at greater risk of developing cancer. To include this modification of risk into radiation protection schemes it is necessary to identify the genes responsible for determining individual sensitivity. Alpha-particle-induced osteosarcoma in the mouse has been adopted as a model of human radiation carcinogenesis, and genome-wide screens have been conducted for allelic imbalance and genetic linkage. These studies have revealed a series of genes involved in determining the sensitivity to radiogenic osteosarcoma formation. (author)

  15. Medical radiation exposure and genetic risks

    International Nuclear Information System (INIS)

    Baker, D.G.

    1980-01-01

    Everyone is exposed to background radiation throughout life (100 mrem/year to the gonads or 4 to 5 rem during the reproductive years). A lumbosacral series might deliver 2500 mrem to the male or 400 mrem to the female gonads. A radiologic procedure is a cost/benefit decision, and genetic risk is a part of the cost. Although cost is usually very low compared to benefit, if the procedure is unnecessary then the cost may be unacceptable. On the basis of current estimates, the doubling dose is assumed to be 40 rem (range 20 to 200) for an acute dose, and 100 rem for protracted exposure. Although there is no satisfactory way to predict the size of the risk for an individual exposed, any risk should be incentive to avoid unnecessary radiation to the gonads. Conception should be delayed for at least ten months for women and three or four months for men after irradiation of the gonads. The current incidence of genetically related diseases in the United States population is 60,000 per million live births. Based on the most conservative set of assumptions, an average gonadal dose of 1000 mrem to the whole population would increase the incidence of genetically related diseases by 0.2%

  16. Genetic damages in radiation workers of radiology centers in Bushehr port

    Directory of Open Access Journals (Sweden)

    Gholamreza Khamisipour

    2004-09-01

    Full Text Available Unstable genetic aberrations might provide a good marker for assessing genetic damage in populations exposed to low levels of ionizing radiation.The frequency of these aberrations was estimated in peripheral lymphocytes from hospital workers in Bushehr Port, occupationally exposed to low levels of ionizing radiation (54 subjects and age and sex matched controls. A total of 34 (23 males & 11 females subjects had unstable genetic aberrations (50 chromosomal-type & 31 chromatid type but only 7 subjects in control group had unstable genetic aberrations. When compared with controls, exposed workers showed a significant increase in structural chromosomal-type aberrations (p<0.001 OR=11 chromosomal exchange being the most frequent alteration. Chromatid deletion (18 cases and ring chromosome (4 cases were seen only in exposed group. There was no association between smoking status, sex, age, level of education or working years. The increased frequencies of chromosomal damage in radiation workers, indicate conducting cytogenetic analysis in parallel to physical dosimetry in the working place.

  17. Genetic alterations during radiation-induced carcinogenesis

    International Nuclear Information System (INIS)

    Kodama, Seiji

    1995-01-01

    This paper reviews radiation-induced genetic alterations and its carcinogenesis, focusing on the previous in vitro assay outcome. A colony formation assay using Syrian hamster fetal cells and focus formation assay using mouse C3H10T1/2 cells are currently available to find malignant transformation of cells. Such in vitro assays has proposed the hypothesis that radiation-induced carcinogenesis arises from at least two-stage processes; i.e., that an early step induced by irradiation plays an important role in promoting the potential to cause the subsequent mutation. A type of genetic instability induced by radiation results in a persistently elevated frequency of spontaneous mutations, so-called the phenomenon of delayed reproductive death. One possible mechanism by which genetic instability arises has been shown to be due to the development of abnormality in the gene group involved in the maintenance mechanism of genome stability. Another possibility has also been shown to stem from the loss of telomere (the extremities of a chromosome). The importance of search for radiation-induced genetic instability is emphasized in view of the elucidation of carcinogenesis. (N.K.)

  18. Genetic effects of radiation. Annex I

    International Nuclear Information System (INIS)

    1982-01-01

    This Annex is aimed at an updating of the 1977 UNSCEAR report, which presented a detailed review of the genetic effects of ionizing radiation, especially those parts that require significant revisions in the light of new data. There is an extensive bibliography with over 1000 references. Particular emphasis is given to those data that are relevant to the evaluation of genetic radiation hazards in man.

  19. Radiation induced genetic damage in Aspergillus nidulans

    International Nuclear Information System (INIS)

    Georgiou, J.T.

    1984-01-01

    The mechanism by which ionizing radiation induces genetic damage in haploid and diploid conidia of Aspergillus nidulans was investigated. Although the linear dose-response curves obtained following low LET irradiation implied a 'single-hit' action of radiation, high LET radiations were much more efficient than low LET radiations, which suggests the involvement of a multiple target system. It was found that the RBE values for non-disjunction and mitotic crossing-over were very different. Unlike mitotic crossing-over, the RBE values for non-disjunction were much greater than for cell killing. This suggests that non-disjunction is a particularly sensitive genetical endpoint that is brought about by damage to a small, probably non-DNA target. Radiosensitisers were used to study whether radiation acts at the level of the DNA or some other cellular component. The sensitisation to electrons and/or X-rays by oxygen, and two nitroimidazoles (metronidazole and misonidazole) was examined for radiation induced non-disjunction, mitotic crossing-over, gene conversion, point mutation and cell killing. It was found that these compounds sensitised the cells considerably more to genetic damage than to cell killing. (author)

  20. Radiation and heredity: genetic aspects of protection against radiation

    International Nuclear Information System (INIS)

    Mosseh, I.B.

    1990-01-01

    Primary radiogenetic effects and delayed genetic radiation effects are considered. Experimental and published data on possibility to protect organisms and populations against single and long-term (during life of several generations) effect of ionizing radiation are given. Problem concerning population adaptation to low dose irradiation is discussed. 490 refs., 28 figs., 43 tabs

  1. Genetic hazards of radiation

    International Nuclear Information System (INIS)

    Searle, A.G.

    1987-01-01

    The difficulties of quantifying genetic radiation effects are discussed, with reference to studies of atomic bomb survivors, and mouse germ-cells. Doubling dose methods of extrapolation and the problems of quantifying risks of diseases of irregular inheritance are also considered. (U.K.)

  2. Radiation genetics. Status and prospects

    International Nuclear Information System (INIS)

    Svyatova, G.S.; Abil'dinova, G.Zh.; Berezina, G.M.

    1997-01-01

    In Republic of Kazakhstan on the base of Republican Scientific and Research Center for Mother and Child Health Protection the comprehensive medical-genetical testing of rural population living in immediate proximity from Semipalatinsk test site is carried out. Besides of general medical-genetic characteristics of examined population the frequency and structure of congenital diseases of newborns from 1970 to 1995 were determined. 67.5 thousand parturitions outcomes in researched area and 21.5 thousand ones in control district (Akmola region) are studied. Both the frequency and the structure of chromosomal aberration of population living on contaminated by radionuclides territories is researched as well. Perspective trends in field of clinical radiation genetics are outlined, there are as follows: - application of early diagnostics and prophylaxis of radiation-induced pathology of both the stochastic and nonstochastic characters; - conducting of biologic dosimetry; - wide application of peri-conception prophylaxis of genetic disorders; - application of anti-mutagens and special food-stuffs making for both the reducing of the absorption and the accumulation of radionuclides in organism; - introduction of long-term programs of correction of developing pathologies caused by multifactorial influence of environment

  3. Problems of radiation genetics. [In Russian

    Energy Technology Data Exchange (ETDEWEB)

    Dubinin, N P

    1956-01-01

    A general review is presented of recent experiments in genetics. Mutant and hereditary effects of the increase in natural radiation and that released by atomic and hydrogen tests were analyzed. Achievements and the possibilities of applying radiation in the induction of selective plant mutations are discussed.

  4. Own experiences in genetic counselling of radiation exposed persons

    International Nuclear Information System (INIS)

    Laude, G.; Bruening, L.

    1995-01-01

    An outline is given of genetic counselling provided to 46 radiation-exposed persons during the period from 1978 to 1994. The radiation exposure had, in most cases, been due to radiation-therapeutic measures (n=22). To a low extent, counselling was carried out because of fear of genetic consequences of the Chernobyl reactor accident (n=11), preceding radiation exposure from X-ray (n=9) and nuclear diagnosis (n=1) as well as occupation radiation exposure (n=3). During counselling, information was given on the genetic risk to be expected, taking into consideration the risk factor that is valid at present and the malformation doubling dose. After performance of radiation therapy, an avoidance of conception for 2 years has been recommended. After termination of this period, in the case of an urgent wish of having children, pregnancy was not discouraged if no further risk factors existed. (orig.) [de

  5. Genetic effects of ionising radiation in man

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1991-01-01

    A review is given of genetic risk estimation in man. Topics covered include the methods used, the germ cell stages and radiation conditions relevant for genetic risk estimation, doubling dose estimates, the classification and prevalence of naturally-occurring genetic disorders, the source of data used in the direct method of risk estimation, the genetic risk estimates from the mid-1970s to the present, the estimates of genetic risk used in ICRP 26 in 1977 and ICRP's current assessment of genetic risks. (UK)

  6. Ionizing radiation and genetic risks

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.; Wassom, J.S.

    2005-01-01

    Recent estimates of genetic risks from exposure of human populations to ionizing radiation are those presented in the 2001 report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). These estimates incorporate two important concepts, namely, the following: (1) most radiation-induced mutations are DNA deletions, often encompassing multiple genes, but only a small proportion of the induced deletions is compatible with offspring viability; and (2) the viability-compatible deletions induced in germ cells are more likely to manifest themselves as multi-system developmental anomalies rather than as single gene disorders. This paper: (a) pursues these concepts further in the light of knowledge of mechanisms of origin of deletions and other rearrangements from two fields of contemporary research: repair of radiation-induced DNA double-strand breaks (DSBs) in mammalian somatic cells and human molecular genetics; and (b) extends them to deletions induced in the germ cell stages of importance for radiation risk estimation, namely, stem cell spermatogonia in males and oocytes in females. DSB repair studies in somatic cells have elucidated the roles of two mechanistically distinct pathways, namely, homologous recombination repair (HRR) that utilizes extensive sequence homology and non-homologous end-joining (NHEJ) that requires little or no homology at the junctions. A third process, single-strand annealing (SSA), which utilizes short direct repeat sequences, is considered a variant of HRR. HRR is most efficient in late S and G 2 phases of the cell cycle and is a high fidelity mechanism. NHEJ operates in all cell cycle phases, but is especially important in G 1 . In the context of radiation-induced DSBs, NHEJ is error-prone. SSA is also an error-prone mechanism and its role is presumably similar to that of HRR. Studies in human molecular genetics have demonstrated that the occurrence of large deletions, duplications or other rearrangements

  7. Ionizing radiation and genetic risks

    Energy Technology Data Exchange (ETDEWEB)

    Sankaranarayanan, K. [Department of Toxicogenetics, Leiden University Medical Centre, Sylvius Laboratories, Wassenaarseweg 72, 2333 AL Leiden (Netherlands)]. E-mail: sankaran@lumc.nl; Wassom, J.S. [YAHSGS, LLC, Richland, WA 99352 (United States); Life Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 (United States)

    2005-10-15

    Recent estimates of genetic risks from exposure of human populations to ionizing radiation are those presented in the 2001 report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). These estimates incorporate two important concepts, namely, the following: (1) most radiation-induced mutations are DNA deletions, often encompassing multiple genes, but only a small proportion of the induced deletions is compatible with offspring viability; and (2) the viability-compatible deletions induced in germ cells are more likely to manifest themselves as multi-system developmental anomalies rather than as single gene disorders. This paper: (a) pursues these concepts further in the light of knowledge of mechanisms of origin of deletions and other rearrangements from two fields of contemporary research: repair of radiation-induced DNA double-strand breaks (DSBs) in mammalian somatic cells and human molecular genetics; and (b) extends them to deletions induced in the germ cell stages of importance for radiation risk estimation, namely, stem cell spermatogonia in males and oocytes in females. DSB repair studies in somatic cells have elucidated the roles of two mechanistically distinct pathways, namely, homologous recombination repair (HRR) that utilizes extensive sequence homology and non-homologous end-joining (NHEJ) that requires little or no homology at the junctions. A third process, single-strand annealing (SSA), which utilizes short direct repeat sequences, is considered a variant of HRR. HRR is most efficient in late S and G{sub 2} phases of the cell cycle and is a high fidelity mechanism. NHEJ operates in all cell cycle phases, but is especially important in G{sub 1}. In the context of radiation-induced DSBs, NHEJ is error-prone. SSA is also an error-prone mechanism and its role is presumably similar to that of HRR. Studies in human molecular genetics have demonstrated that the occurrence of large deletions, duplications or other

  8. Genetic and chromosomal effects of ionizing radiation

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The genetic and chromosomal effects of ionizing radiations deal with those effects in the descendants of the individuals irradiated. The information base concerning genetic and chromosomal injury to humans from radiation is less adequate than is the information base for cancer and leukemia. As a result, it is not possible to make the kinds of quantitative estimates that have been made for carcinogenesis in previous chapters of this book. The chapter includes a detailed explanation of various types of genetic injuries such as chromosomal diseases, x-linked diseases, autosomal dominant diseases, recessive diseases, and irregularly inherited diseases. Quantitative estimates of mutation rates and incidences are given based on atomic bomb survivors data

  9. Radiation as agents of somatic and genetic alterations

    International Nuclear Information System (INIS)

    de Eston, V.R.

    1975-01-01

    According to the report on ''The Effects on Population of Exposure to Low Levels of Ionizing Radiation,'' whether we regard a risk as acceptable or not depends on how avoidable it is, and, if not avoidable, how it compares with the risks of alternative options and those usually accepted by society. Regarding the use of ionizing radiation: No exposure should be permitted without the expectation of a commensurable benefit. The public must be protected from radiation, but not to the extent that the degree of protection provided results in the substitution of a worse hazard than that of the radiation avoided. Medical radiation exposure can and should be reduced considerably by limiting its use to clinically indicated procedures, utilizing efficient exposure techniques and optimal operation of radiation equipment. Consideration should be given to the following: (a) Restriction of the use of radiation for public health purposes, unless there is reasonable probability of significant detection of disease. (b) Inspection and licensing of radiation and ancillary equipment. (c) Appropriate training and certification of involved personnel. (d) Gonad shielding, especially shielding of the testis, is strongly recommended as a simple and highly efficient way to reduce the genetic significant dose. In a poignant phrase, Morgan has stated ''Radiation doesn't have to be feared, but should be respected.''

  10. Molecular genetic researches on the radiation genetics of Drosophila in JINR

    International Nuclear Information System (INIS)

    Afanas'eva, K.P.; Aleksandrova, M.V.; Aleksandrov, I.D.

    2016-01-01

    Molecular genetic studies of radiation-induced heritable DNA lesions are carried out by the genetic group of Laboratory of nuclear problem in Joint Institute for Nuclear Research. The first results of molecular analysis of γ –ray- and neutron-induced vestigial mutations using PCR and sequencing will be presented. (authors)

  11. Radiation-sensitive genetically susceptible pediatric sub-populations

    Energy Technology Data Exchange (ETDEWEB)

    Kleinerman, Ruth A. [National Cancer Institute, NIH, DHHS, Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, Rockville, MD (United States)

    2009-02-15

    Major advances in pediatric cancer treatment have resulted in substantial improvements in survival. However, concern has emerged about the late effects of cancer therapy, especially radiation-related second cancers. Studies of childhood cancer patients with inherited cancer syndromes can provide insights into the interaction between radiation and genetic susceptibility to multiple cancers. Children with retinoblastoma (Rb), neurofibromatosis type 1 (NF1), Li-Fraumeni syndrome (LFS), and nevoid basal cell carcinoma syndrome (NBCCS) are at substantial risk of developing radiation-related second and third cancers. A radiation dose-response for bone and soft-tissue sarcomas has been observed in hereditary Rb patients, with many of these cancers occurring in the radiation field. Studies of NF1 patients irradiated for optic pathway gliomas have reported increased risks of developing another cancer associated with radiotherapy. High relative risks for second and third cancers were observed for a cohort of 200 LFS family members, especially children, possibly related to radiotherapy. Children with NBCCS are very sensitive to radiation and develop multiple basal cell cancers in irradiated areas. Clinicians following these patients should be aware of their increased genetic susceptibility to multiple primary malignancies enhanced by sensitivity to ionizing radiation. (orig.)

  12. Mouse genetic approaches applied to the normal tissue radiation response

    International Nuclear Information System (INIS)

    Haston, Christina K.

    2012-01-01

    The varying responses of inbred mouse models to radiation exposure present a unique opportunity to dissect the genetic basis of radiation sensitivity and tissue injury. Such studies are complementary to human association studies as they permit both the analysis of clinical features of disease, and of specific variants associated with its presentation, in a controlled environment. Herein I review how animal models are studied to identify specific genetic variants influencing predisposition to radiation-induced traits. Among these radiation-induced responses are documented strain differences in repair of DNA damage and in extent of tissue injury (in the lung, skin, and intestine) which form the base for genetic investigations. For example, radiation-induced DNA damage is consistently greater in tissues from BALB/cJ mice, than the levels in C57BL/6J mice, suggesting there may be an inherent DNA damage level per strain. Regarding tissue injury, strain specific inflammatory and fibrotic phenotypes have been documented for principally, C57BL/6 C3H and A/J mice but a correlation among responses such that knowledge of the radiation injury in one tissue informs of the response in another is not evident. Strategies to identify genetic differences contributing to a trait based on inbred strain differences, which include linkage analysis and the evaluation of recombinant congenic (RC) strains, are presented, with a focus on the lung response to irradiation which is the only radiation-induced tissue injury mapped to date. Such approaches are needed to reveal genetic differences in susceptibility to radiation injury, and also to provide a context for the effects of specific genetic variation uncovered in anticipated clinical association studies. In summary, mouse models can be studied to uncover heritable variation predisposing to specific radiation responses, and such variations may point to pathways of importance to phenotype development in the clinic.

  13. Genetic and somatic effects of ionizing radiation

    International Nuclear Information System (INIS)

    1986-01-01

    This is the ninth substantive report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) to the General Assembly. This report contains reviews on three special topics in the field of biological effects of ionizing radiation that are among those presently under consideration by the Committee: genetic effects of radiation, dose-response relationships for radiation-induced cancer and biological effects of pre-natal irradiation

  14. Ionizing radiation, genetic risks and radiation protection

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1992-01-01

    With one method of risk estimation, designed as the doubling dose method, the estimates of total genetic risk (i.e., over all generation) for a population continuously exposed at a rate of 0.01 Gy/generation of low LET irradiation are about 120 cases of Mendelian and chromosomal diseases/10 6 live births and about the same number of cases for multifactorial diseases (i.e., a total of 240 cases/10 6 ). These estimates provide the basis for risk coefficients for genetic effects estimated by ICRP (1991) in its Publication 60. These are: 1.0%/Sv for the general population (which is 40% of 240/10 6 /0.01 Gy), and 0.6%/Sv for radiation workers (which is 60% of that for the general population). The results of genetic studies carried out on the Japanese survivors of A-bombs have shown no significant adverse effects attributable to parental radiation exposures. The studies of Gardner and colleagues suggest that the risk of leukaemia in children born to male workers in the nuclear reprocessing facility in Sellafield, U.K., may be increased. However, this finding is at variance with the results from the Japanese studies and at present, does not lend itself to a simple interpretation based on radiobiological principles. In the light of recent advances in the molecular biology of naturally-occurring human Mendelian diseases and what we presently know about multifactorial diseases, arguments are advanced to support the thesis that (i) current risk estimates for Mendelian diseases may be conservative and (ii) an overall doubling dose for all adverse genetic effects may be higher than the 1 Gy currently used (i.e., the relative risks are probably lower). (author)

  15. International conference. The problems of radiation genetics at the turn of the century. Abstracts

    International Nuclear Information System (INIS)

    2000-01-01

    Information concerning International conference: The problems of radiation genetics at the turn of the century - held in Moscow, November, 2000, is presented. The conference is dedicated to the memory of Timofeev-Resovsky (centenary of birth). Analysis of the development of concepts of the radiation genetics founder concerning study of genetic radiation effects on plants, animals and man is given. Molecular-genetic mechanisms of radiation mutagenesis are considered. Problems related to the analysis of delayed genetic radiation effects on the different types. Populations and regularities in radiation-induced mutagenesis at cellular, tissue and body levels are discussed. Great attention is paid to the genetic consequences for population, flora and fauna of Chernobyl and Kyshtym accidents, nuclear explosions at Semipalatinsk test site and other emergency radiation situations [ru

  16. Genetic effects of ionizing radiation and repair processes

    International Nuclear Information System (INIS)

    Tuschl, H.

    1986-11-01

    Since DNA (=desoxyribonucleic acid) is the largest molecule within the cell it is the most important target for direct and indirect radiation effects. Within DNA the total genetic information is stored, thus damage to DNA in germ cells causes genetic disorders and damage in somatic cells is implicated in cancer and immunodeficiences. Alterations of DNA structure are not only due to ionizing radiation effects, but also to spontaneous DNA modifications and damage from interactions with environmental ultraviolet light and chemical agents. To maintain its genetic integrity, each organism had to develop different repair systems able to recognize and remove DNA damage. Repeated exposure to a DNA damaging agent can even lead to adaptation processes and increased resistance to the same agent. At normal function of repair systems it can be assumed that the capacity of those systems is adequate to scope with the effects of low radiation doses. (Author)

  17. Genetic and epigenetic features in radiation sensitivity. Part I: Cell signalling in radiation response

    International Nuclear Information System (INIS)

    Bourguignon, Michel H.; Gisone, Pablo A.; Perez, Maria R.; Michelin, Severino; Dubner, Diana; Giorgio, Marina di; Carosella, Edgardo D.

    2005-01-01

    Recent progress especially in the field of gene identification and expression has attracted greater attention to genetic and epigenetic susceptibility to cancer, possibly enhanced by ionising radiation. It has been proposed that the occurrence and severity of the adverse reactions to radiation therapy are also influenced by such genetic susceptibility. This issue is especially important for radiation therapists since hypersensitive patients may suffer from adverse effects in normal tissues following standard radiation therapy, while normally sensitive patients could receive higher doses of radiation offering a better likelihood of cure for malignant tumours. This paper, the first of two parts, reviews the main mechanisms involved in cell response to ionising radiation. DNA repair machinery and cell signalling pathways are considered and their role in radiosensitivity is analysed. The implication of non-targeted and delayed effects in radiosensitivity is also discussed. (orig.)

  18. Significance of genetic predisposition and genomic instability for individual sensitivity to radiation. Implications for radiation protection

    International Nuclear Information System (INIS)

    Heller, H.

    2001-01-01

    At its closed-door meeting on 20/21 January 2000 the Radiation Protection Committee dedicated much of its attention to the significance of genetic predisposition and genetic instability for individual radiation sensitivity and to the implication of this for radiation protection. The statements and contributions to the closing plenary discussion touched on many aspects of ethics, personal rights, occupational medicine and insurance issues relating to this subject, all of which extend far beyond the purely technical issues of radiation protection. The present volume contains the lecture manuscripts of the meeting as well as a summarising assessment by the Radiation Protection Committee [de

  19. Comparison of gamma radiation and radiomimmetic chemical, bleomycin in leukocytes from certain genetic disorders

    International Nuclear Information System (INIS)

    Saraswathy, Radha

    2004-01-01

    Full text: To compare the frequency and distribution pattern of bleomycin and gamma radiation induced chromosomal aberrations in human genetic disorders. To study if the induced chromosomal break points are specific for specific human genetic disorders. Human genetics disorders such as; retinitis pigmentosa, retinoblastoma, xeroderma pigmentosa and gonadal dysgenesis were used in our study. Suitable controls were maintained. The frequency and distribution pattern of chromosomal break points in individual chromosomes were determined in lymphocytes exposed to 50r of gamma radiation and 10μg/ml of bleomycin for 3h at G2. In normal individuals none of the unirradiated leukocyte cultures of any syndrome showed any accountable number of chromosomal aberrations. The frequency of radiation induced chromosomal break points showed a non random distribution pattern and frequently clustered at some specific chromosome regions to form hot spots. Lack of linear-quadratic dose response was observed in the lymphocyte exposed to bleomycin in normal individual. The frequency of chromosomal aberrations in the whole genome for the genetic disorders were higher than the controls and a varying distribution pattern of bleomycin induced breaks per cell was observed

  20. Genetical effects of radiations from products of nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Spiers, F W

    1955-01-01

    Relative radiation dose-rates to man and to Drosophila are discussed. Data previously presented by Prof. J.B.S. Haldane on the genetical effects of radiation resulting from nuclear explosions are reviewed. A reply from Prof. Haldane presents revised calculations of radiation dose rates.

  1. Genetic effects of formaldehyde in yeast. Current status and limitations of the radiation equivalence concept

    International Nuclear Information System (INIS)

    Chanet, R.; Magana-Schwencke, N.; Moustacchi, E.

    1980-01-01

    Values of radiation equivalents of chemicals have been calculated for formaldehyde (FA) from detailed data on its genetic effects on yeast, Saccharomyces cerevisiae, and compared with the effects induced by gamma radiation. For the haploid yeast strain, 1 (mmol FA.ltr -1 ).min (i.e. 1 mM FA.min) is equivalent to 9.6 rad, and for diploid yeast it is equivalent to 33 rad. These values are within the range of values calculated for E. coli and mammalian cells. Some major differences in the response to FA and radiation are encountered, depending upon the cellular physiological conditions, the genetic background and the degree of ploidy (haploid versus diploid) and growth phase (exponential versus stationary), among others. Difficulties encountered in the estimation of rad-equivalent values for specific chemicals and for defined biological end-points (e.g. rate of reverse mutation in the specific biochemical loci) are discussed. It is concluded that by exercising appropriate caution relating to the differences in the mechanisms of action of the chemical mutagens and radiations, meaningful rad-equivalent values could be estimated that could help express the comparative biological effects of chemicals in terms of radiation unit. (author)

  2. Effects of UV radiation on genetic recombination

    International Nuclear Information System (INIS)

    Vlahovic, K.; Zahradka, D.; Petranovic, M.; Petranovic, D.

    1996-01-01

    We have used the model consisting of Escherichia coli cells and l phage to study the effects of UV radiation on genetic recombination. We found two radiation induced processes that reduce or inhibit genetic recombination. One such process leads to the inability of prophage to excise itself from the irradiated bacterial chromosome by the site-specific recombination. The other process was shown to inhibit a type of general recombination by which the prophage transfers one of its genetic markers to the infecting homologous phage. Loss of the prophage ability to take part in both site-specific and general recombination was shown to develop in recB + but not in recB cells. From this we infer that the loss of prophage recombinogenicity in irradiated cells is a consequence of one process in which RecBCD enzyme (the product of recB, recC and recD genes) plays an essential role. (author)

  3. Assessment of genetic risk for human exposure to radiation

    International Nuclear Information System (INIS)

    Sevcenko, V.A.; Rubanovic, A.V.

    2002-01-01

    Full text: The methodology of assessing the genetic risk of radiation exposure is based on the concept of 'hitting the target' in development of which N.V. Timofeeff-Ressovsky has played and important role. To predict genetic risk posed by irradiation, the U N Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has worked out direct and indirect methods of assessment, extrapolation, integral and palpitation criteria of risk analysis that together permit calculating the risk from human exposure on the basis of data obtained for mice. Based on the reports of UNSCEAR for the period from 1958 to 2001 the paper presents a retrospective analysis of the use of direct methods and the doubling dose method for quantitative determination of the genetic risk of human exposure expressed as different hereditary diseases. As early as 1962 UNSCEAR estimated the doubling dose (a dose causing as many mutations as those occurring spontaneously during one generation) at 1 Gy for cases of exposure to ionizing radiations with low LET at a low dose rate and this value was confirmed in the next UNSCEAR reports up to now. For cases of acute irradiation the doubling dose was estimated at 0,3-0,4 Gy for the period under review. The paper considers the evolution of the concepts of human natural hereditary variability which is a basis for assessing the risk of exposure by the doubling dose method. The level of human natural genetic variability per 1 000 000 newborns is estimated at 738 000 hereditary diseases including mendelian, chromosomal and multifactorial ones. The greatest difficulties in assessing the doubling dose value were found to occur in the case of multifactorial diseases the pheno typical expression of which depends on mutational events in polygenic systems and on numerous environmental factors. The introduction in calculations of the potential recoverability correction factor (RPCF) made it possible to assess the genetic risk taking into account this class of

  4. Radiation induced mutants in elite genetic background for the augmentation of genetic diversity

    International Nuclear Information System (INIS)

    Kumar, V.; Bhagwat, S.G.

    2011-01-01

    Rice (Oryza sativa L.), an important food crop for India, shows large genetic diversity. However, despite the large genetic resource, high genetic similarity is reported in cultivated varieties indicating genetic erosion. Radiation induced mutations provide genetic variability in elite background. In the present study, twenty gamma ray induced mutants of rice variety WL112 (carrying sd-1 semi-dwarfing gene) were analysed for genetic diversity using microsatellite markers. The high range of genetic diversity among mutants indicated that the mutants possess potential for enhancing variability in rice. Cluster analysis showed presence of five clusters having small sub-clusters. Earliness, semi-dwarf stature or resistance to blast disease observed among the mutants showed that these will be useful in breeding programmes. (author)

  5. Radiation application on development of marker genes for genetic manipulation

    International Nuclear Information System (INIS)

    Lee, Young Il

    1997-04-01

    This state of art report was dealt with the recent progress of genetic engineering techniques and prospect of gene manipulation. Especially the selection of new genetic marker genes such as variants to environmental stress, pest or insect resistance, herbicide resistance and nutritional requirement was reviewed by using plant cell and tissue culture combined with radiation mutation induction. Biotechnology has taken us from the era hybrid plants to the era of transgenic plants. Although there are still many problems to solve in transformation method and the regeneration of transformed cell and tissue. Genetic marker genes are very important material to improve the technique of genetic manipulation. Most of the genes have been developed by radiation. (author). 180 refs., 6 tabs

  6. Assessment of genetic results of ionizing radiation effect on hydrobionts population

    International Nuclear Information System (INIS)

    Pechkurenkov, V.L.; Pokrovskaya, L.G.; Fetisov, A.N.

    1987-01-01

    The effect of dose value and rate on genetic results of chronic radiation with the low dose rate is estimated. At such irradiation the yield of abberant anaphases of embryos is determined by the dose value and it does not depend on the dose rate. The threshold radiation dose rate of the developing fish roe equals 2-3 cGy/h when ignoring the medium modifying factors. The estimation of possible limits of modification of genetic effects of radiation with the low rate when changing environmental factors is given. The model allowing to forecast the appearance of genetic effects of radiation with the low dose rate is constructed. The correspondence between the data obtained in laboratory experiments using organisms living in water reservoirs contaminated experimentally by radionuclides is marked

  7. Naturally occurring and radiation-induced tumors in SPF mice, and genetic influence in radiation leukemogenesis

    International Nuclear Information System (INIS)

    Kasuga, T.

    1979-01-01

    The data obtained so far in this study point to a strong genetic influence not only on the types and incidence of naturally occurring and radiation-induced tumors but also on radiation leukemogenesis. (Auth.)

  8. Genetic effects of ionizing radiations in Eucaryocytes

    International Nuclear Information System (INIS)

    Jullien, Pierre

    1976-01-01

    The litterature on the genetic effects of ionizing radiations is reviewed, especially as concerns specific loci or chromosome mutations. Extrapolation from one species to another is considered as well as extra-nuclear mutations [fr

  9. Genetic and epigenetic features in radiation sensitivity. Part II: implications for clinical practice and radiation protection

    International Nuclear Information System (INIS)

    Bourguignon, Michel H.; Gisone, Pablo A.; Perez, Maria R.; Michelin, Severino; Dubner, Diana; Giorgio, Marina di; Carosella, Edgardo D.

    2005-01-01

    Recent progress especially in the field of gene identification and expression has attracted greater attention to the genetic and epigenetic susceptibility to cancer, possibly enhanced by ionising radiation. This issue is especially important for radiation therapists since hypersensitive patients may suffer from adverse effects in normal tissues following standard radiation therapy, while normally sensitive patients could receive higher doses of radiation, offering a better likelihood of cure for malignant tumours. Although only a small percentage of individuals are ''hypersensitive'' to radiation effects, all medical specialists using ionising radiation should be aware of the aforementioned progress in medical knowledge. The present paper, the second of two parts, reviews human disorders known or strongly suspected to be associated with hypersensitivity to ionising radiation. The main tests capable of detecting such pathologies in advance are analysed, and ethical issues regarding genetic testing are considered. The implications for radiation protection of possible hypersensitivity to radiation in a part of the population are discussed, and some guidelines for nuclear medicine professionals are proposed. (orig.)

  10. Induction of genetic instability by ionizing radiation

    International Nuclear Information System (INIS)

    Little, J.B.

    1999-01-01

    Evidence is presented to support the hypothesis that radiation may induce a heritable, genome-wide process of instability that leads to an enhanced frequency of genetic changes occurring among the progeny of the original irradiated cell. This instability is transmissible over many generations of cell replication. Mutational instability is induced in a relatively large fraction (approximately 10 %) of the cell population, and may be modulated by factors acting in vivo. Thus, it cannot be a targeted event involving a specific gene or set of genes. There is no dose-response relationship in the range 2-12 Gy, suggesting that the instability phenotype may be induced by quite low radiation doses. The molecular mechanisms associated with the genesis of mutations in unstable populations differ from those for direct X-ray-induced mutations. These results suggest that it may not be possible to predict the nature of the dose-response relationship for the ultimate genetic effects of radiation based on a qualitative or quantitative analysis of the original DNA lesions. (author)

  11. Environmental chemical mutagens and genetic risks: Lessons from radiation genetics

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1996-01-01

    The last three decades have witnessed substantial progress in the development and use of a variety of in vitro and in vivo assay systems for the testing of environmental chemicals which may pose a mutagenic hazard to humans. This is also true of basic studies in chemical mutagenesis on mechanisms, DNA repair, molecular dosimetry, structure-activity relationships, etc. However, the field of quantitative evaluation of genetic risks of environmental chemicals to humans is still in it infancy. This commentary addresses the question of how our experience in estimating genetic risks of exposure to ionizing radiation can be helpful in similar endeavors with environmental chemical mutagens. 24 refs., 3 tabs

  12. Genetic and molecular dosimetry of HZE radiation (US-1 RADIAT)

    Science.gov (United States)

    Nelson, Gregory A.; Schubert, W. W.; Kazarians, G. A.; Richards, G. F.; Benton, E. V.; Benton, E. R.; Henke, R. P.

    1995-01-01

    In order to estimate radiation exposure in space, experiments were conducted during the 1st International Microgravity Laboratory (IML-1) mission in order to isolate genetic changes in animal cells caused by cosmic rays. The space measurements were evaluated against results from synthetic cosmic rays produced by particle accelerators on the ground. The biological material used was the tiny soil nematode, Caenorhabditis elegans. The measurements were made by thermoluminescent detectors and plastic nuclear track detectors. The development and the chromosome mechanics in microgravity were studied, and the mutagenesis induced by radiation exposure was analyzed. The results showed that there are no obvious differences in the development, behavior and chromosome mechanics, as a function of gravity unloading (reproduction, self-fertilization and mating of males with hermaphrodites, gross anatomy, symmetry and gametogenesis, pairing, disjoining and recombination of chromosomes). A variety of mutants were isolated, and it was noted that mutants isolated from regions of identified high particles were more severely affected than those isolated by random screening. Linear energy transfer particles seem to favor large scale genetic lesions.

  13. Evolution of Genetic Variance during Adaptive Radiation.

    Science.gov (United States)

    Walter, Greg M; Aguirre, J David; Blows, Mark W; Ortiz-Barrientos, Daniel

    2018-04-01

    Genetic correlations between traits can concentrate genetic variance into fewer phenotypic dimensions that can bias evolutionary trajectories along the axis of greatest genetic variance and away from optimal phenotypes, constraining the rate of evolution. If genetic correlations limit adaptation, rapid adaptive divergence between multiple contrasting environments may be difficult. However, if natural selection increases the frequency of rare alleles after colonization of new environments, an increase in genetic variance in the direction of selection can accelerate adaptive divergence. Here, we explored adaptive divergence of an Australian native wildflower by examining the alignment between divergence in phenotype mean and divergence in genetic variance among four contrasting ecotypes. We found divergence in mean multivariate phenotype along two major axes represented by different combinations of plant architecture and leaf traits. Ecotypes also showed divergence in the level of genetic variance in individual traits and the multivariate distribution of genetic variance among traits. Divergence in multivariate phenotypic mean aligned with divergence in genetic variance, with much of the divergence in phenotype among ecotypes associated with changes in trait combinations containing substantial levels of genetic variance. Overall, our results suggest that natural selection can alter the distribution of genetic variance underlying phenotypic traits, increasing the amount of genetic variance in the direction of natural selection and potentially facilitating rapid adaptive divergence during an adaptive radiation.

  14. Modeling solar radiation of Mediterranean region in Turkey by using fuzzy genetic approach

    International Nuclear Information System (INIS)

    Kisi, Ozgur

    2014-01-01

    The study investigates the ability of FG (fuzzy genetic) approach in modeling solar radiation of seven cities from Mediterranean region of Anatolia, Turkey. Latitude, longitude, altitude and month of the year data from the Adana, K. Maras, Mersin, Antalya, Isparta, Burdur and Antakya cities are used as inputs to the FG model to estimate one month ahead solar radiation. FG model is compared with ANNs (artificial neural networks) and ANFIS (adaptive neruro fuzzzy inference system) models with respect to RMSE (root mean square errors), MAE (mean absolute errors) and determination coefficient (R 2 ) statistics. Comparison results indicate that the FG model performs better than the ANN and ANFIS models. It is found that the FG model can be successfully used for estimating solar radiation by using latitude, longitude, altitude and month of the year information. FG model with RMSE = 6.29 MJ/m 2 , MAE = 4.69 MJ/m 2 and R 2 = 0.905 in the test stage was found to be superior to the optimal ANN model with RMSE = 7.17 MJ/m 2 , MAE = 5.29 MJ/m 2 and R 2 = 0.876 and ANFIS model with RMSE = 6.75 MJ/m 2 , MAE = 5.10 MJ/m 2 and R 2 = 0.892 in estimating solar radiation. - Highlights: • SR (Solar radiation) of seven cities from Mediterranean region of Turkey is predicted. • FG (Fuzzy genetic) models are developed for accurately estimation of SR. • The ability of the FG models used in the study is found to be satisfactory. • FG models are compared with commonly used ANNs (artificial neural networks). • FG models are found to perform better than the ANNs models

  15. Studies on the genetic effects of radiation

    International Nuclear Information System (INIS)

    Cheong, Kyu Hoi; Cheong, Hae Won; Cheon, Kwi Cheong; Kim, Chae Sung

    1985-01-01

    To investigate genetic damage of radiation in mammalian male germ cell, sperm head counts, frequency of sperm with abnormal head shape, fertility, activity of LDH-X, and the induction of unscheduled DNA synthesis in testis were measured periodically after irradiation. Sperm head counts and activities of LDH-X in testes were gradually reduced by increased radiation dose and with the passing of the time after irradiation. Frequency occurrence of sperm of abnormal head shape, sterile period, and the induction of unscheduled DNA synthesis were increased. (Author)

  16. Modification of genetic effects of gamma radiation by laser radiation

    International Nuclear Information System (INIS)

    Khotyljova, L.V.; Khokhlova, S.A.; Khokhlov, I.V.

    1988-01-01

    Full text: Mutants obtained by means of ionizing radiation and chemical mutagens often show low viability and productivity that makes their use in plant breeding difficult. Methods reducing the destructive mutagen action on important functions of plant organism and increasing quality and practical value of induced mutants would be interesting. We believe that one method for increasing efficiency of experimental mutagenesis in plants is the application of laser radiation as a modificator of genetic effects of ionizing radiation and chemical mutagens. Combined exposure of wheat seedlings to a gamma radiation dose of 2 kR and to laser radiation with the wave length of 632.8 nm (power density - 20 mVt/cm 2 , exposure - 30 min.) resulted in reducing the chromosomal aberration percentage from 30.5% in the gamma version to 16.3% in the combined treatment version. A radiosensibilizing effect was observed at additional exposure of gamma irradiated wheat seeds to laser light with the wave length of 441.6 nm where chromosomal aberration percentage increased from 22% in the gamma-irradiation version to 31% in the combined treatment version. By laser radiation it is also possible to normalize mitotic cell activity suppressed by gamma irradiation. Additional seedling irradiation with the light of helium-neon laser (632.8 nm) resulted in recovery of mitotic cell activity from 21% to 62% and increasing the average content of DNA per nucleus by 10%. The influence of only laser radiation on plant variability was also studied and it was shown that irradiation of wheat seeds and seedlings with pulsed and continuous laser light of visible spectrum resulted in phenotypically altered forms in M 2 . Their frequencies was dependent upon power density, dose and radiation wave length. Number of altered forms increased in going from long-wave to short-wave spectrum region. In comparing efficiency of different laser types of pulsed and continuous exposure (dose - 180 J/cm 2 ) 2% of altered

  17. Solar Radiation-Associated Adaptive SNP Genetic Differentiation in Wild Emmer Wheat, Triticum dicoccoides.

    Science.gov (United States)

    Ren, Jing; Chen, Liang; Jin, Xiaoli; Zhang, Miaomiao; You, Frank M; Wang, Jirui; Frenkel, Vladimir; Yin, Xuegui; Nevo, Eviatar; Sun, Dongfa; Luo, Ming-Cheng; Peng, Junhua

    2017-01-01

    Whole-genome scans with large number of genetic markers provide the opportunity to investigate local adaptation in natural populations and identify candidate genes under positive selection. In the present study, adaptation genetic differentiation associated with solar radiation was investigated using 695 polymorphic SNP markers in wild emmer wheat originated in a micro-site at Yehudiyya, Israel. The test involved two solar radiation niches: (1) sun, in-between trees; and (2) shade, under tree canopy, separated apart by a distance of 2-4 m. Analysis of molecular variance showed a small (0.53%) but significant portion of overall variation between the sun and shade micro-niches, indicating a non-ignorable genetic differentiation between sun and shade habitats. Fifty SNP markers showed a medium (0.05 ≤ F ST ≤ 0.15) or high genetic differentiation ( F ST > 0.15). A total of 21 outlier loci under positive selection were identified by using four different F ST -outlier testing algorithms. The markers and genome locations under positive selection are consistent with the known patterns of selection. These results suggested that genetic differentiation between sun and shade habitats is substantial, radiation-associated, and therefore ecologically determined. Hence, the results of this study reflected effects of natural selection through solar radiation on EST-related SNP genetic diversity, resulting presumably in different adaptive complexes at a micro-scale divergence. The present work highlights the evolutionary theory and application significance of solar radiation-driven natural selection in wheat improvement.

  18. Somatic and genetic radiation exposure of the patient in digital subtraction angiography (DSA)

    International Nuclear Information System (INIS)

    Neufang, K.F.R.; Ewen, K.

    1986-01-01

    The somatic and genetic radiation exposure of patients undergoing Digital Subtraction Angiography (DSA) and traditional Film Arteriography (FA) of cranial, cervical, thoracic and abdominal vascular territories are compared. The radiation doses absorbed within the critical organs - red bone marrow, lung, thyroid gland and female breast - and in the gonads were measured using an anthropomorphic Alderson phantom. A Somatic Dose Index was calculated in order to estimate the somatic radiation risk. The somatic radiation exposure depends upon the location of the critical organs with respect to the entrance site of the x-ray beam, and can be reduced by an appropriate choice of the angiographic projection. Under this condition, the radiation exposure of the patient during DSA can be lower than during FA. For renal DSA an a.p. projection, the use of an abdominal compression device and careful caudal shielding of the field are advocated. (orig.)

  19. Population-genetic approach to standardization of radiation and non-radiation factors

    International Nuclear Information System (INIS)

    Telnov, I.

    2006-01-01

    population level. Of 65 analyses of association between diseases and unfavorable effects and various genetic polymorphic systems, 27 had negative results. Other 38 had significant, i.e. positive results. Respective G.S.R.R. varied accordingly in the range from 1.2 to 2.5. Averaged G.S.R.R. for some genetic systems ranged from 1.4 to 1.9. More stable and closer values of averaged G.S.R.R. calculated for various categories of effects: pathologies due to radiation and non-radiation factors - 1.51; non-tumor (1,47) and tumor (1,54) diseases; average life expectancy - 1.34. Population-averaged or integral value of G.S.R.R. was about 1.5. This value can be used as genetic predisposition coefficient (C.G.P.) for correction in averaging of environmental population level factors. Such correction can be done by decreasing of permissible standard value by the value of C.G.P. to calculate population-genetic standard. It should be noted that population-genetic standards decrease risk of development of unfavorable consequences due to effect of environmental factors in individuals with genetic predisposition to the general population level. An important advantage of this approach is that there is no need to account for all existing variations of genetic predisposition to multiform unfavorable environmental factors

  20. Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Kleiman, Norman Jay [Columbia University

    2013-11-30

    The lens of the eye is one of the most radiosensitive tissues in the body. Ocular ionizing radiation exposure results in characteristic, dose related, progressive lens changes leading to cataract formation. While initial, early stages of lens opacification may not cause visual disability, the severity of such changes progressively increases with dose until vision is impaired and cataract extraction surgery may be required. Because of the transparency of the eye, radiation induced lens changes can easily be followed non-invasively over time. Thus, the lens provides a unique model system in which to study the effects of low dose ionizing radiation exposure in a complex, highly organized tissue. Despite this observation, considerable uncertainties remain surrounding the relationship between dose and risk of developing radiation cataract. For example, a growing number of human epidemiological findings suggest significant risk among various groups of occupationally and accidentally exposed individuals and confidence intervals that include zero dose. Nevertheless, questions remain concerning the relationship between lens opacities, visual disability, clinical cataract, threshold dose and/or the role of genetics in determining radiosensitivity. Experimentally, the response of the rodent eye to radiation is quite similar to that in humans and thus animal studies are well suited to examine the relationship between radiation exposure, genetic determinants of radiosensitivity and cataractogenesis. The current work has expanded our knowledge of the low-dose effects of X-irradiation or high-LET heavy ion exposure on timing and progression of radiation cataract and has provided new information on the genetic, molecular, biochemical and cell biological features which contribute to this pathology. Furthermore, findings have indicated that single and/or multiple haploinsufficiency for various genes involved in DNA repair and cell cycle checkpoint control, such as Atm, Brca1 or Rad9

  1. Genetic damage from low-level and natural background radiation

    International Nuclear Information System (INIS)

    Oftedal, P.

    1988-01-01

    Relevant predictions that have been made of possible low level biological effects on man are reviewed, and the estimate of genetic damage is discussed. It is concluded that in spite of a number of attempts, no clear-cut case of effects in human populations of radiation at natural levels has been demonstrated. The stability of genetic material is dynamic, with damage, repair and selection running as continuous processes. Genetic materials are well protected and are conservative in the extreme, not least because evolution by genetic adaptation is an expensive process: Substitution of one allele A 1 by another A 2 means the death of the whole A 1 population

  2. The genetics of radiation-induced and sporadic osteosarcoma: a unifying theory?

    International Nuclear Information System (INIS)

    Rosemann, Michael; Kuosaite, Virginija; Nathrath, Michaela; Atkinson, Michael J.

    2002-01-01

    Cancer is a disease of the genome, with the neoplastic phenotype being passed from one cell generation to the other. Radiation-induced cancer has often been considered to represent a unique entity amongst neoplasia, with the energy deposition being held responsible for both direct (gene mutations) and indirect (bystander effects, induced instability etc) alterations to the cellular genome. However, radiogenic tumours in man and experimental animals appear to be physiologically and genetically indistinguishable from their sporadic counterparts, suggesting that the aetiologies of these two tumour types are in fact closely related. We have conducted a general screen of the genetic alterations in radiation-induced mouse osteosarcoma, a tumour that is histopathologically indistinguishable from human sporadic osteosarcoma. Comparison of the two tumour types indicates the existence of a common set of genetic changes, providing additional evidence to support the concept that the molecular pathology of radiation-induced malignancy is no different to that of sporadic cancers. (author)

  3. Genetic effects of ionizing radiation – some questions with no answers

    International Nuclear Information System (INIS)

    Mosse, Irma B.

    2012-01-01

    There are a lot of questions about genetic effects of ionizing radiation, the main one is does ionizing radiation induce mutations in humans? There is no direct evidence that exposure of parents to radiation leads to excess heritable disease in offspring. What is the difference between human and other species in which radiation induced mutations are easily registered? During evolution germ cell selection ex vivo has been changed to a selection in vivo and we cannot observe such selection of radiation damaged cells in human. Low radiation doses – are they harmful or beneficial? The “hormesis” phenomenon as well as radioadaptive response proves positive effects of low radiation dose. Can analysis of chromosomal aberration rate in lymphocytes be used for dosimetry? Many uncontrolled factors may be responsible for significant mistakes of this method. Why did evolution preserve the bystander effect? This paper is discussion one and its goal is to pay attention on some effects of ionizing radiation. - Highlights: ► There are a lot of questions about genetic effects of ionizing radiation. ► Does ionizing radiation induce mutations in human? ► During evolution germ cell selection ex vivo has been changed to a selection in vivo. ► Radioadaptive response proves positive effects of low radiation doses. ► Many uncontrolled factors may be responsible for significant biodosimetry mistakes.

  4. Age differences in genetic effect of radiation

    International Nuclear Information System (INIS)

    Ohanjanian, E.E.; Sahakian, D.G.; Khachatrian, G.A.; Mkrtichian, S.A.

    1975-01-01

    The age differences in the radiosensitivity of the genetic apparatus of spleen cells, lymphatic ganglion and the epithelium of the mucous uterus have been revealed. In mice not having reached puberty the chromosomes of the cells of the above-mentioned organs are more sensitive to a single radiation dose of 100 R than in mice having reached puberty. (author)

  5. Genetic Modeling of Radiation Injury in Prostate Cancer Patients Treated with Radiotherapy

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-15-1-0681 TITLE: Genetic Modeling of Radiation Injury in Prostate Cancer Patients Treated with Radiotherapy PRINCIPAL...TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0681Genetic Modeling of Radiation Injury in Prostate Cancer Patients Treated...effects, urinary morbidity, rectal injury, sexual dysfunction 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF

  6. Gonadal radiation dose and its genetic significance in radioiodine therapy of hyperthyroidism

    International Nuclear Information System (INIS)

    Robertson, J.S.; Gorman, C.A.

    1976-01-01

    Published estimates of radiation dose to the gonads from 131 I therapy of Graves' disease vary widely, largely because of differences in assumptions regarding the details of iodine kinetics. The calculations described in this paper show that hyperthyroid patients treated with 10 mCi of 131 I will usually receive a total radiation dose to the ovaries or testes of less than 3 rad. Several common roentgenographic diagnostic procedures may involve a greater radiation dose and a greater genetic hazard than does the usual 131 I treatment for hyperthyroidism. It is important to minimize total exposure to radiation, but it seems unreasonable to deny 131 I treatment for hyperthyroidism to young men and nonpregnant young women on the grounds of genetic hazard alone

  7. Cumulative genetic damage in children exposed to preconception and intrauterine radiation

    International Nuclear Information System (INIS)

    Bross, I.D.; Natarajan, N.

    1980-01-01

    Using a mathematical model and newly developed computer software, the data from the Tri-State Leukemia Survey involving different combinations of radiation exposures to the father and mother prior to conception and to the mother during pregnancy were analyzed. The hypothesis that radiation exposure produces genetic damage which may be expressed in the child both as indicator disease and as leukemia was tested. The genetic damage was estimated in terms of the proportion affected by a given exposure. The relative risk of leukemia and certain other indicator diseases among those affected could then be estimated. The results show that there are at least two distinguishable risk groups, one group with lower (one or two exposures); and the other group with higher (two or three) radiation exposures

  8. A Systems Genetic Approach to Identify Low Dose Radiation-Induced Lymphoma Susceptibility/DOE2013FinalReport

    Energy Technology Data Exchange (ETDEWEB)

    Balmain, Allan [University of California, San Francisco; Song, Ihn Young [University of California, San Francisco

    2013-05-15

    The ultimate goal of this project is to identify the combinations of genetic variants that confer an individual's susceptibility to the effects of low dose (0.1 Gy) gamma-radiation, in particular with regard to tumor development. In contrast to the known effects of high dose radiation in cancer induction, the responses to low dose radiation (defined as 0.1 Gy or less) are much less well understood, and have been proposed to involve a protective anti-tumor effect in some in vivo scientific models. These conflicting results confound attempts to develop predictive models of the risk of exposure to low dose radiation, particularly when combined with the strong effects of inherited genetic variants on both radiation effects and cancer susceptibility. We have used a Systems Genetics approach in mice that combines genetic background analysis with responses to low and high dose radiation, in order to develop insights that will allow us to reconcile these disparate observations. Using this comprehensive approach we have analyzed normal tissue gene expression (in this case the skin and thymus), together with the changes that take place in this gene expression architecture a) in response to low or high- dose radiation and b) during tumor development. Additionally, we have demonstrated that using our expression analysis approach in our genetically heterogeneous/defined radiation-induced tumor mouse models can uniquely identify genes and pathways relevant to human T-ALL, and uncover interactions between common genetic variants of genes which may lead to tumor susceptibility.

  9. Genetic variation in resistance to ionizing radiation

    International Nuclear Information System (INIS)

    Ayala, F.J.

    1991-01-01

    We proposed an investigation of genetically-determined individual differences in sensitivity to ionizing radiation. The model organism is Drosophila melanogaster. The gene coding for Cu,Zn superoxide dismutase (SOD) is the target locus, but the effects of variation in other components of the genome that modulate SOD levels are also taken into account. SOD scavenges oxygen radicals generated during exposure to ionizing radiation. It has been shown to protect against ionizing radiation damage to DNA, viruses, bacteria, mammalian cells, whole mice, and Drosophila. Two alleles, S and F, are commonly found in natural populations of D. melanogaster; in addition we have isolated from a natural population ''null'' (CA1) mutant that yields only 3.5% of normal SOD activity. The S, F, and CA1 alleles provide an ideal model system to investigate SOD-dependent radioresistance, because each allele yields different levels of SOD, so that S > F >> CA1. The roles of SOD level in radioresistance are being investigated in a series of experiments that measure the somatic and germ-line effects of increasing doses of ionizing radiation. In addition, we have pursued an unexpected genetic event-namely the nearly simultaneous transformation of several lines homozygous for the SOD ''null'' allele into predominately S lines. Using specifically designed probes and DNA amplification by means of the Tag polymerase chain reaction (PCR) we have shown that (1) the null allele was still present in the transformed lines, but was being gradually replaced by the S allele as a consequence of natural selection; and (2) that the transformation was due to the spontaneous deletion of a 0.68 Kb truncated P-element, the insertion of which is characteristic of the CA1 null allele

  10. Genetic and somatic radiation doses in radiotherapy of inflammatory and degenerative diseases of bones, joints and soft parts

    Energy Technology Data Exchange (ETDEWEB)

    Kirsch, M.; Keinert, K.; Schumann, E. (Medizinische Akademie, Erfurt (German Democratic Republic). Radiologische Klinik)

    1983-01-01

    Dose measurements were performed in several body regions of patients suffering from inflammatory degenerative diseases (humeral epicondylitis, humeroscapular periarthritis, gonarthrosis, axillary hidradenitis, rheumatoid arthritis, coxarthrosis, parotitis). The problem of the radiation induction of neoplasms is predominant concerning somatic as well as genetic risk, discussed by example of the most frequently occurring organ cancer. Compared to the rate of breast cancer in the highly developed industrial states (5,000 to 6,000 cancers/100,000 women) the 'radiation induction' calculated according to a mathematical model of ICRP 26 (1.25 cases of death for breast cancers/100,000 women following for example irradiation of epicondylitis) is behind several powers of ten and not demonstrable. The genetic radiation exposure is also low. Derived from the measurements it is wrong to give up reliable and approved indications of radiotherapy of non-malignant diseases because of unfounded radiophobia.

  11. Genetic analysis of resistance to radiation lymphomagenesis with recombinant inbred strains of mice

    International Nuclear Information System (INIS)

    Okumoto, M.; Nishikawa, R.; Imai, S.; Hilgers, J.

    1990-01-01

    Induction of lymphomas by radiation in mice is controlled by genetic factors. We analyzed the genetic control of radiation lymphomagenesis using the CXS series of recombinant inbred strains derived from two progenitor strains: one highly susceptible to radiation induction of lymphoma [BALB/cHeA (C)] and one extremely resistant [STS/A (S)]. The best concordances between strain distribution patterns of genetic markers and resistance (or susceptibility) to radiation lymphomagenesis were observed in a region with the b and Ifa genes on chromosome 4. This indicates that one major locus controls the incidence of radiogenic lymphomas in mice. We designated this locus as the Lyr (lymphoma resistance) locus. Backcrosses of (CXS)F1 to the two progenitor strains showed an intermediate incidence of lymphomas between their parental mice and did not significantly differ from (CXS)F1 mice. This and previous observations that (CXS)F1 mice also showed an intermediate incidence, differing from both progenitor strains, indicate that more genes are involved in the resistance (or susceptibility) to lymphoma induced by irradiation

  12. Cellular and genetic effects and recovery of heat-damaged cells of Saccharomyces cerevisiae by low intensity electromagnetic radiation at 915 MHz

    International Nuclear Information System (INIS)

    Sheikh, I.H.

    1984-01-01

    Studies were conducted on two genetically well known strains of Saccharomyces cerevisiae (Wild Type) and repair deficient mutant (UVS). Results obtained showed clear genetic difference between normal and mutants based on UV sensitivity, percent survival at elevated temperatures and high intensity electromagnetic radiation. At the cellular level, both strains showed a consistent increase in the recovery rate of heat damaged cells when exposed to low intensity FMR as compared to sham (non irradiated cells) at 915 MHz. The percent recovery of wild type was higher than mutant. At the molecular level, the uptake of tritiated uridine into thermally damaged cells which were recovered by low level EMR was significantly higher than sham. Total RNA isolated from irradiated cells and sham showed visible differences in the intensity of RNA bands. Gross quantitative analyses suggest more RNA production in radiation recovered cells as compared to sham. Results presented in this dissertation provide conclusive evidence that low level microwave radiation can be used in the recovery of heat damaged cells

  13. James V. Neel and Yuri E. Dubrova: Cold War debates and the genetic effects of low-dose radiation.

    Science.gov (United States)

    Goldstein, Donna M; Stawkowski, Magdalena E

    2015-01-01

    This article traces disagreements about the genetic effects of low-dose radiation exposure as waged by James Neel (1915-2000), a central figure in radiation studies of Japanese populations after World War II, and Yuri Dubrova (1955-), who analyzed the 1986 Chernobyl nuclear power plant accident. In a 1996 article in Nature, Dubrova reported a statistically significant increase in the minisatellite (junk) DNA mutation rate in the children of parents who received a high dose of radiation from the Chernobyl accident, contradicting studies that found no significant inherited genetic effects among offspring of Japanese A-bomb survivors. Neel's subsequent defense of his large-scale longitudinal studies of the genetic effects of ionizing radiation consolidated current scientific understandings of low-dose ionizing radiation. The article seeks to explain how the Hiroshima/Nagasaki data remain hegemonic in radiation studies, contextualizing the debate with attention to the perceived inferiority of Soviet genetic science during the Cold War.

  14. Tentative estimations of genetic hazards for the atomic bomb radiations, Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Yoshikawa, Isao; Ayaki, Toshikazu

    1978-01-01

    The degree of genetic hazards which could appear in the offspring of A-bomb survivors (after F1) was estimated on the basis of a report by the United Nations Scientific Committee on the Effects of Atomic Radiation in 1977. The genetic effects of atomic bomb radiation on humans (insufficient data) were investigated on the basis of data obtained from animal experiments (especially mice). The incidence of chromosome aberration and gene mutation induced by radiation was estimated based on data obtained from experiments with marmosets and mice, respectively. The appearance time and frequency of chromosome aberration and dominant mutation were estimated based on the incidence of mutation induced by radiation. The effects of recessive mutation were determined by estimating the probability of such mutation in a presumed human group by means of a simulation method in which a computer was used. (Tsunoda, M.)

  15. New technique for global solar radiation forecasting by simulated annealing and genetic algorithms using

    International Nuclear Information System (INIS)

    Tolabi, H.B.; Ayob, S.M.

    2014-01-01

    In this paper, a novel approach based on simulated annealing algorithm as a meta-heuristic method is implemented in MATLAB software to estimate the monthly average daily global solar radiation on a horizontal surface for six different climate cities of Iran. A search method based on genetic algorithm is applied to accelerate problem solving. Results show that simulated annealing based on genetic algorithm search is a suitable method to find the global solar radiation. (author)

  16. Comparative Analysis of Genetic Crossover Operators in Knapsack ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Knapsack problem via GA (Genetic Algorithm) is presented. We compared ... Keywords: Genetic Algorithm, Crossover, Heuristic, Arithmetic, Intermediate, Evolutionary Algorithm. The knapsack .... application to 0/1 Knapsack problem, Applied.

  17. A Genetic Algorithm Based Optimization Scheme To Find The Best Set Of Design Parameters To Enhance The Performance Of An Automobile Radiator

    Directory of Open Access Journals (Sweden)

    G.Chaitanya

    2013-12-01

    Full Text Available The present work aims at maximizing the overall heat transfer rate of an automobile radiator using Genetic Algorithm approach. The design specifications and empirical data pertaining to a rally car radiator obtained from literature are considered in the present work. The mathematical function describing the objective for the problem is formulated using the radiator core design equations and heat transfer relations governing the radiator. The overall heat transfer rate obtained from the present optimization technique is found to be 9.48 percent higher compared to the empirical value present in the literature. Also, the enhancement in the overall heat transfer rate is achieved with a marginal reduction in the radiator dimensions indicating better spacing ratio compared to the existing design.

  18. Problems and solutions in the estimation of genetic risks from radiation and chemicals

    International Nuclear Information System (INIS)

    Russell, W.L.

    1980-01-01

    Extensive investigations with mice on the effects of various physical and biological factors, such as dose rate, sex and cell stage, on radiation-induced mutation have provided an evaluation of the genetics hazards of radiation in man. The mutational results obtained in both sexes with progressive lowering of the radiation dose rate have permitted estimation of the mutation frequency expected under the low-level radiation conditions of most human exposure. Supplementing the studies on mutation frequency are investigations on the phenotypic effects of mutations in mice, particularly anatomical disorders of the skeleton, which allow an estimation of the degree of human handicap associated with the occurrence of parallel defects in man. Estimation of the genetic risk from chemical mutagens is much more difficult, and the research is much less advanced. Results on transmitted mutations in mice indicate a poor correlation with mutation induction in non-mammalian organisms

  19. The impact of advances in human molecular biology on radiation genetic risk estimation in man

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1996-01-01

    This paper provides an overview of the conceptual framework, the data base, methods and assumptions used thus far to assess the genetic risks of exposure of human populations to ionising radiation. These are then re-examined in the contemporary context of the rapidly expanding knowledge of the molecular biology of human mendelian diseases. This re-examination reveals that (i) many of the assumptions used thus far in radiation genetic risk estimation may not be fully valid and (ii) the current genetic risk estimates are probably conservative, but provide an adequate margin of safety for radiological protection. The view is expressed that further advances in the field of genetic risk estimation will be largely driven by advances in the molecular biology of human genetic diseases. (author). 37 refs., 5 tabs

  20. Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Buhl, T.E.; Hansen, W.R.

    1984-05-01

    Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables

  1. Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Buhl, T.E.; Hansen, W.R.

    1984-05-01

    Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables.

  2. Proceedings of the 15. Berzelius symposium on somatic and genetic effects of ionizing radiation

    International Nuclear Information System (INIS)

    Stigbrand, T.

    1989-01-01

    The symposium begins with a brush up on the physics of ionizing radiation and a background to the natural and man-made source of radiation to which we are exposed. The next section deals with the origin and nature of radiation-induced damage to DNA. The somatic effects of ionizing radiation span from DNA lesions to various effects on cell structure and cell function and effects on whole organs. The somatic effects are immediate as well as long-term, with mental impairment and an increased risk for carcinogenesis as consequences of main concern. The genetic effects of ionizing radiation can result in: infertility, spontaneous abortions, genetic diseases and malformations and increased risk for cancer. This leads over to the problems of risk estimation. Risk estimation which is mainly based on experimental data using animal models, human cell lines and epidemiological studies of exposed and unexposed populations

  3. Optimisation of the radiation shielding of medical cyclotrons using a genetic algorithm

    International Nuclear Information System (INIS)

    Mukherjee, Bhaskar

    2000-01-01

    Effective radiation shielding is imperative for safe operation of modern Medical Cyclotrons producing large activities of short-lived radioisotopes on a commercial basis. The optimal cyclotron shielding design demands a careful balance between the radiological, economical and often the sociopolitical factors. One is required to optimize the cost of radiation protection and the cost of radiological-health detriment. The cost of radiation protection depends explicitly on a) the nature of the radiation field produced by the cyclotron, b) the cyclotron operation condition, c) the cost of shielding material, d) the level of dose reduction, e) the projected net revenue from the sale of the radioisotopes, and f) the depreciation rate of the cyclotron facility. The Genetic Algorithm (GA) is used for a cost -benefit analysis of this problem. The GA is a mathematical technique that emulates the Darwinian Evolution paradigm. It is ideally suited to search for a global optimum in a large multi-dimensional solution space, having demonstrated strength compared to the classical analytical methods. Furthermore the GA method runs on a PC in a Windows environment. This paper highlights an interactive spreadsheet macro program for the cost benefit analysis of the optimize Medical Cyclotron shielding using a GA search engine. (author)

  4. Radiation, hypoxia and genetic stimulation: implications for future therapies

    International Nuclear Information System (INIS)

    Adams, Gerald E.; Hasan, Na'il M.; Joiner, Michael C.

    1997-01-01

    The cellular stress response, whereby very low doses of cytotoxic agents induce resistance to much higher doses, is an evolutionary defence mechanism and is stimulated following challenges by numerous chemical, biological and physical agents including particularly radiation, drugs, heat and hypoxia. There is much homology in the effects of these agents which are manifest through the up-regulation of various genetic pathways. Low-dose radiation stress influences processes involved in cell-cycle control, signal transduction pathways, radiation sensitivity, changes in cell adhesion and cell growth. There is also homology between radiation and other cellular stress agents, particularly hypoxia. Whereas traditionally, hypoxia was regarded mainly as an agent conferring resistance to radiation, there is now much evidence illustrating the cytokine-like properties of hypoxia as well as radiation. Stress phenomena are likely to be important in risks arising from low doses of radiation. Conversely, exploitation of the stress response in settings appropriate to therapy can be particularly beneficial not only in regard to radiation alone but in combinations of radiation and drugs. Similarly, tissue hypoxia can be exploited in novel ways of enhancing therapeutic efficacy. Bioreductive drugs, which are cytotoxically activated in hypoxic regions of tissue, can be rendered even more effective by hypoxia-induced increased expression of enzyme reductases. Nitric oxide pathways are influenced by hypoxia thereby offering possibilities for novel vascular based therapies. Other approaches are discussed

  5. Effects of Pharmacological Inhibition and Genetic Deficiency of Plasminogen Activator Inhibitor-1 in Radiation-Induced Intestinal Injury

    International Nuclear Information System (INIS)

    Abderrahmani, Rym; Francois, Agnes; Buard, Valerie; Benderitter, Marc; Sabourin, Jean-Christophe; Crandall, David L.; Milliat, Fabien

    2009-01-01

    Purpose: To investigate effects of plasminogen activator inhibitor 1 (PAI-1) genetic deficiency and pharmacological PAI-1 inhibition with PAI-039 in a mouse model of radiation-induced enteropathy. Methods and Materials: Wild-type (Wt) and PAI-1 -/- knockout mice received a single dose of 19 Gy to an exteriorized localized intestinal segment. Sham and irradiated Wt mice were treated orally with 1 mg/g of PAI-039. Histological modifications were quantified using a radiation injury score. Moreover, intestinal gene expression was monitored by real-time PCR. Results: At 3 days after irradiation, PAI-039 abolished the radiation-induced increase in the plasma active form of PAI-1 and limited the radiation-induced gene expression of transforming growth factor β1 (TGF-β1), CTGF, PAI-1, and COL1A2. Moreover, PAI-039 conferred temporary protection against early lethality. PAI-039 treatment limited the radiation-induced increase of CTGF and PAI-1 at 2 weeks after irradiation but had no effect at 6 weeks. Radiation injuries were less severe in PAI-1 -/- mice than in Wt mice, and despite the beneficial effect, 3 days after irradiation, PAI-039 had no effects on microscopic radiation injuries compared to untreated Wt mice. Conclusions: A genetic deficiency of PAI-1 is associated with amelioration of late radiation enteropathy. Pharmacological inhibition of PAI-1 by PAI-039 positively impacts the early, acute phase increase in plasma PAI-1 and the associated radiation-induced gene expression of inflammatory/extracellular matrix proteins. Since PAI-039 has been shown to inhibit the active form of PAI-1, as opposed to the complete loss of PAI-1 in the knockout animals, these data suggest that a PAI-1 inhibitor could be beneficial in treating radiation-induced tissue injury in acute settings where PAI-1 is elevated.

  6. Genetic risks associated with radiation exposures during space flight

    International Nuclear Information System (INIS)

    Grahn, D.

    1983-01-01

    Although the genetic risks of space radiation do not pose a significant hazard to the general population, the risks may be very important to the individual astronaut. The present paper summarizes some experimental results on the induction of dominant lethal mutations and chromosomal damage in the first generation which may be used in the prediction of the genetic risks of radiation exposures of space crews. Young adult male mice were exposed to single, weekly and continuous doses of gamma rays, neutrons in single doses and weekly exposures and continuous doses of Pu-239 alpha particles. Evaluation of fetal survival rates in females mated to the exposed males shows the mutation rate in individuals exposed to gamma rays to decline as the exposure period is prolonged and the dose rate is reduced, while the response to neutrons is in the opposite direction. Cytological determinations show the rate of balanced chromosomal translocations to drop as gamma ray exposures change from one-time to continuous, however little or no dose rate effect is seen with neutron radiation and alpha particle exposure shows no regular dose-response. Based on the above results, it is predicted that the rate of dominant mutations and transmissible chromosome aberrations in astronauts on a 100-day mission will increase by 4.5 to 41.25 percent over the spontaneous rate. 35 references

  7. International conference. The problems of radiation genetics at the turn of the century. Abstracts; Mezhdunarodnaya konferentsiya. Problemy radiatsionnoj genetiki na rubezhe vekov. Tezisy dokladov

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Information concerning International conference: The problems of radiation genetics at the turn of the century - held in Moscow, November, 2000, is presented. The conference is dedicated to the memory of Timofeev-Resovsky (centenary of birth). Analysis of the development of concepts of the radiation genetics founder concerning study of genetic radiation effects on plants, animals and man is given. Molecular-genetic mechanisms of radiation mutagenesis are considered. Problems related to the analysis of delayed genetic radiation effects on the different types. Populations and regularities in radiation-induced mutagenesis at cellular, tissue and body levels are discussed. Great attention is paid to the genetic consequences for population, flora and fauna of Chernobyl and Kyshtym accidents, nuclear explosions at Semipalatinsk test site and other emergency radiation situations.

  8. Susceptibility to radiation-induced mammary carcinoma in genetically resistant Copenhagen rats

    International Nuclear Information System (INIS)

    Kamiya, Kenji; Nitta, Yumiko; Gould, M.N.

    2000-01-01

    The objective of this experiment was to compare the cellular basis of mammary cancer induction by a chemical carcinogen with induction by ionizing radiation in three strains of rats (inbred that have different genetic susceptibilities: COP rats, F344 rats, and WF rats). Rats were given a single intraperitoneal injection of 50 mg MNU/kg body weight as a mammary-tumor-inducing chemical carcinogen and were irradiated with a 3.0 Gy dose of 60 Co gamma rays at a dose rate of 26.58±1.19 cGy/min. The rats were inspected weekly, and they were killed and necropsied whenever palpable tumors were detected or they became moribund. The histopathological and immunohistochemical characteristics of the mammary tumors were investigated. A transplantation experiment using selected primary mammary tumors that developed in COP rats exposed to gamma rays was also performed to investigate the transplantability of mammary tumors induced by ionizing radiation. The sensitivity of the WF and F344 rats and the resistance of the COP rats to mammary carcinoma induction by the chemical carcinogen MNU was confirmed. In contrast to the chemical carcinogens, no difference in susceptibility to radiation induction of mammary carcinomas was detected among the three strains of rats, and immunohistochemical examination indicated that the radiation-induced carcinomas consisted of more highly differentiated cells than the MNU-induced cancers. The results of the experiment appear to support the hypothesis that differentiated mammary gland tissue is more resistant to chemical carcinogens than to cancer induction by radiation. The authors conclude that radiation-induced cancers in rats may develop via different pathways or from different cell populations than chemically induced cancers. (K.H.)

  9. Susceptibility to radiation-induced mammary carcinoma in genetically resistant Copenhagen rats

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, Kenji; Nitta, Yumiko [Hiroshima Univ. (Japan). Research Inst. for Radiation Biology and Medicine; Gould, M.N.

    2000-07-01

    The objective of this experiment was to compare the cellular basis of mammary cancer induction by a chemical carcinogen with induction by ionizing radiation in three strains of rats (inbred that have different genetic susceptibilities: COP rats, F344 rats, and WF rats). Rats were given a single intraperitoneal injection of 50 mg MNU/kg body weight as a mammary-tumor-inducing chemical carcinogen and were irradiated with a 3.0 Gy dose of {sup 60} Co gamma rays at a dose rate of 26.58{+-}1.19 cGy/min. The rats were inspected weekly, and they were killed and necropsied whenever palpable tumors were detected or they became moribund. The histopathological and immunohistochemical characteristics of the mammary tumors were investigated. A transplantation experiment using selected primary mammary tumors that developed in COP rats exposed to gamma rays was also performed to investigate the transplantability of mammary tumors induced by ionizing radiation. The sensitivity of the WF and F344 rats and the resistance of the COP rats to mammary carcinoma induction by the chemical carcinogen MNU was confirmed. In contrast to the chemical carcinogens, no difference in susceptibility to radiation induction of mammary carcinomas was detected among the three strains of rats, and immunohistochemical examination indicated that the radiation-induced carcinomas consisted of more highly differentiated cells than the MNU-induced cancers. The results of the experiment appear to support the hypothesis that differentiated mammary gland tissue is more resistant to chemical carcinogens than to cancer induction by radiation. The authors conclude that radiation-induced cancers in rats may develop via different pathways or from different cell populations than chemically induced cancers. (K.H.)

  10. Human genetic studies in areas of high natural radiation

    International Nuclear Information System (INIS)

    Freire-Maia, A.; Krieger, H.

    1978-01-01

    Data have been obtained by a genetic-epidemiological survey of a population living in the State of Espirito Santo (Brazil), and subjected to mean levels of natural radiation, per locality, ranging from 7 to 133 μrad/hr. Multiple regression models have been applied to the data, and the results showed no detectable effect of natural radiation on the sex ratio at birth, on the occurrence of congenital anomalies, and on the numbers of pregnancy terminations, stillbirths, livebirths, and post-infant mortality in the children, as well as fecundity and fertility of the couples (these observations contradict some data from the literature, based on official records and without analyses of the concomitant effects of other variables). However, nonsignificant results cannot be considered as disproving harmful effects of natural radiation on mortality and morbidity. These results may simply mean that other causes of mortality and morbidity are so important, under the conditions of the study, that the contribution of low-level, chronic natural radiation is made negligible. (author)

  11. A search for genetic effects of atomic bomb radiation on the growth and development of the F1 generation, 3

    International Nuclear Information System (INIS)

    Furusho, Toshiyuki; Otake, Masanori.

    1980-02-01

    In a search for possible genetic effects of atomic bomb radiation on the stature of the offspring of A-bomb survivors a comparative study has been made of junior high school students 12 to 14 years of age born in Hiroshima to exposed and nonexposed parents. The mean stature and variance of the offspring and the covariance and correlation between one parent or the sum for both parents and their children were compared. The observed differences were both positive and negative in sign, and only a few were statistically significant. No clear tendency was demonstrated. When one parent was exposed, seven variance values of the offspring were statistically significant and six were positive in sign. Regression analyses of the mean stature and variance of the offspring, or the covariance, and correlation between one parent or the sum for both parents and their offspring by parental radiation dose revealed no clear effects of exposure. Only a very few of the regression coefficients were significantly different from zero. While genetic effects of A-bomb radiation on the stature of the children of exposed parents cannot be ruled out by this study, neither can such effects be unequivocally demonstrated. (author)

  12. Genetically uniform strains of fish as laboratory models for experimental studies of the effects of ionizing radiation

    International Nuclear Information System (INIS)

    Woodhead, A.D.; Setlow, R.B.; Hart, R.W.

    1979-01-01

    The advantages are discussed of using a genetically uniform test animal such as the amazon molly, Poecilia formosa, to reduce the biotic variability in experimental determination of the effects of ionizing radiation on aquatic ecosystems. Besides a cost reduction from using less organisms for these radiation-effect studies, another significant advantage of the higher precision responses due to homozygous genetic material is the assessment of radiation effects at the molecular and cellular levels. (author)

  13. The relevance of animal experimental results for the assessment of radiation genetic risks in man

    International Nuclear Information System (INIS)

    Stephan, G.

    1981-01-01

    No suitable data are available from man for the quantitative assessment of genetic radiation risk. Therefore, the results from experiments on animals must be utilized. Two hypotheses are presented here in drawing analogical conclusions from one species to another. Although the extrapolation of results from animal experiments remains an open question, the use of experimental results from mice seems to be justified for an assessment of the genetic radiation risk in man. (orig.) [de

  14. Comparative Approaches to Genetic Discrimination: Chasing Shadows?

    Science.gov (United States)

    Joly, Yann; Feze, Ida Ngueng; Song, Lingqiao; Knoppers, Bartha M

    2017-05-01

    Genetic discrimination (GD) is one of the most pervasive issues associated with genetic research and its large-scale implementation. An increasing number of countries have adopted public policies to address this issue. Our research presents a worldwide comparative review and typology of these approaches. We conclude with suggestions for public policy development. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Genetic analysis of radiation-induced mouse thymic lymphomas

    International Nuclear Information System (INIS)

    Kominami, R.; Wakabayashi, Y.; Niwa, O.

    2003-01-01

    Mouse thymic lymphomas are one of the classic models of radiation-induced malignancies, and the model has been used for the study of genes involved in carcinogenesis. ras oncogenes are the first isolate which undergoes mutations in 10 to 30 % of lymphomas, and p16INK4a and p19ARF in the INK4a-ARF locus are also frequently inactivated. In our previous study, the inactivation of Ikaros, a key regurator of lymphoid system, was found in those lymphomas, and it was suggested that there are other responsible genes yet to be discovered. On the other hand, genetic predisposition to radiation-induced lymphoma often differs in different strains, and this reflects the presence of low penetrance genes that can modify the impact of a given mutation. Little study of such modifiers or susceptibility genes has been performed, either. Recent availability of databases on mouse genome information and the power of mouse genetic system underline usefulness of the lymphoma model in search for novel genes involved, which may provide clues to molecular mechanisms of development of the radiogenic lymphoma and also genes involved in human lymphomas and other malignancies. Accordingly, we have carried out positional cloning for the two different types of tumor-related genes. In this symposium, our current progress is presented that includes genetic mapping of susceptibility/ resistance loci on mouse chromosomes 4, 5 and 19, and also functional analysis of a novel tumor suppressor gene, Rit1/Bcl11b, that has been isolated from allelic loss (LOH) mapping and sequence analysis for γ -ray induced mouse thymic lymphomas

  16. FitSKIRT: genetic algorithms to automatically fit dusty galaxies with a Monte Carlo radiative transfer code

    Science.gov (United States)

    De Geyter, G.; Baes, M.; Fritz, J.; Camps, P.

    2013-02-01

    We present FitSKIRT, a method to efficiently fit radiative transfer models to UV/optical images of dusty galaxies. These images have the advantage that they have better spatial resolution compared to FIR/submm data. FitSKIRT uses the GAlib genetic algorithm library to optimize the output of the SKIRT Monte Carlo radiative transfer code. Genetic algorithms prove to be a valuable tool in handling the multi- dimensional search space as well as the noise induced by the random nature of the Monte Carlo radiative transfer code. FitSKIRT is tested on artificial images of a simulated edge-on spiral galaxy, where we gradually increase the number of fitted parameters. We find that we can recover all model parameters, even if all 11 model parameters are left unconstrained. Finally, we apply the FitSKIRT code to a V-band image of the edge-on spiral galaxy NGC 4013. This galaxy has been modeled previously by other authors using different combinations of radiative transfer codes and optimization methods. Given the different models and techniques and the complexity and degeneracies in the parameter space, we find reasonable agreement between the different models. We conclude that the FitSKIRT method allows comparison between different models and geometries in a quantitative manner and minimizes the need of human intervention and biasing. The high level of automation makes it an ideal tool to use on larger sets of observed data.

  17. Radiation and genetic consequences of ionizing radiation on population of Pinus sylvestris L. within the zone of the Chernobyl NPP

    International Nuclear Information System (INIS)

    Fedotov, I.S.; Kal'chenko, V.A.; Igonina, E.V.; Rubanovich, A.V.

    2006-01-01

    Main results of the nineteen year monitoring of genetic radiation effects of ionizing radiations on pines of forest plantation in the zone of the Chernobylsk NPP accident are presented. It is shown that the acute ionizing irradiation at radiation doses >1 Gy induces the formation of morphosis and depressed growth, and at doses >2 Gy, the reproductive ability of pines is declined. The radiobiological parameters have practically linear dose-dependence relationship. The acute irradiation at dose of 0.5 Gy induces cytogenetic and genetic effects that are significantly higher than corresponding control values. The relationship between the cytogenetic effects and the absorbed dose is exponential. The dependence of mutation frequency at specific loci on the absorbed dose is described by a nonlinear curve. The results of the cytogenetic analysis of seedlings obtained from seeds annually collected in zones of slight, moderate and strong damages of pines are presented [ru

  18. A comparative map viewer integrating genetic maps for Brassica and Arabidopsis

    Directory of Open Access Journals (Sweden)

    Erwin Timothy A

    2007-07-01

    Full Text Available Abstract Background Molecular genetic maps provide a means to link heritable traits with underlying genome sequence variation. Several genetic maps have been constructed for Brassica species, yet to date, there has been no simple means to compare this information or to associate mapped traits with the genome sequence of the related model plant, Arabidopsis. Description We have developed a comparative genetic map database for the viewing, comparison and analysis of Brassica and Arabidopsis genetic, physical and trait map information. This web-based tool allows users to view and compare genetic and physical maps, search for traits and markers, and compare genetic linkage groups within and between the amphidiploid and diploid Brassica genomes. The inclusion of Arabidopsis data enables comparison between Brassica maps that share no common markers. Analysis of conserved syntenic blocks between Arabidopsis and collated Brassica genetic maps validates the application of this system. This tool is freely available over the internet on http://bioinformatics.pbcbasc.latrobe.edu.au/cmap. Conclusion This database enables users to interrogate the relationship between Brassica genetic maps and the sequenced genome of A. thaliana, permitting the comparison of genetic linkage groups and mapped traits and the rapid identification of candidate genes.

  19. Genetical variability of Gladioli as the result of gamma-radiation

    International Nuclear Information System (INIS)

    Jakota, L.I.; Murin, A.V.

    1994-01-01

    In the starting material of Gladioli, got in the result of Y-radiation, the forms with white spots on the petals were observed. The Gladioli form 165-81 is distinguished by low growth and middle early flowering. The flower form is triangular. Basic pigmentation is red. White spots of different size on the petals were observed. The investigation was made in 1992 in the field of genetical variability of Gladioli. The Gladioli form 165-81 was irradiated with gamma-radiation dose 30 Gr. As a result the depression of biometric indicators was observed. Consequently, 30 Gr is a mutant dose for Gladioli

  20. Genetic effects of high LET radiations

    International Nuclear Information System (INIS)

    Grahn, D.; Garriott, M.L.; Farrington, B.H.; Lee, C.H.; Russell, J.J.

    1981-01-01

    The objectives of this project are: (1) to assess genetic hazards from testicular burdens of 239 Pu and determine its retention and microdistribution in the testis; (2) to compare effects of 239 Pu with single, weekly, and continuous 60 Co gamma irradiation and single and weekly fission neutron irradiation to develop a basis for estimating relative biological effectiveness (RBE); and (3) to develop detailed dose-response data for genetic end points of concern at low doses of neutrons and gamma rays. Comparatively short-term genetic end points are used, namely: (1) the dominant lethal mutation rate in premeiotic and postmeiotic cell stages; (2) the frequency of abnormal sperm head morphology measured at various times after irradiation; and (3) the frequency of reciprocal chromosome translocations induced in spermatogonia and measured at first meiotic metaphase. Male hybrid B6CF 1 mice, 120 days old, are used for all studies. Measures of the retention, microdistributionand pollutant related changes. Assessment of human risk associated with nuclearing collective dose commitment will result in more attention being paid to potential releases of radionuclides at relatively short times after disposal

  1. Comparing estimates of genetic variance across different relationship models.

    Science.gov (United States)

    Legarra, Andres

    2016-02-01

    Use of relationships between individuals to estimate genetic variances and heritabilities via mixed models is standard practice in human, plant and livestock genetics. Different models or information for relationships may give different estimates of genetic variances. However, comparing these estimates across different relationship models is not straightforward as the implied base populations differ between relationship models. In this work, I present a method to compare estimates of variance components across different relationship models. I suggest referring genetic variances obtained using different relationship models to the same reference population, usually a set of individuals in the population. Expected genetic variance of this population is the estimated variance component from the mixed model times a statistic, Dk, which is the average self-relationship minus the average (self- and across-) relationship. For most typical models of relationships, Dk is close to 1. However, this is not true for very deep pedigrees, for identity-by-state relationships, or for non-parametric kernels, which tend to overestimate the genetic variance and the heritability. Using mice data, I show that heritabilities from identity-by-state and kernel-based relationships are overestimated. Weighting these estimates by Dk scales them to a base comparable to genomic or pedigree relationships, avoiding wrong comparisons, for instance, "missing heritabilities". Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Genetic dissection of mammalian ERAD through comparative haploid and CRISPR forward genetic screens

    DEFF Research Database (Denmark)

    Timms, Richard T.; Menzies, Sam A.; Tchasovnikarova, Iva A.

    2016-01-01

    The application of forward genetic screens to cultured human cells represents a powerful method to study gene function. The repurposing of the bacterial CRISPR/Cas9 system provides an effective method to disrupt gene function in mammalian cells, and has been applied to genome-wide screens. Here, we...... compare the efficacy of genome-wide CRISPR/Cas9-mediated forward genetic screens versus gene-trap mutagenesis screens in haploid human cells, which represent the existing ‘gold standard’ method. This head-to-head comparison aimed to identify genes required for the endoplasmic reticulum....../3-associated disulphide reductase. Genome-wide CRISPR/Cas9-mediated screens together with haploid genetic screens provide a powerful addition to the forward genetic toolbox....

  3. Somatic and genetic effects of low-level radiation

    International Nuclear Information System (INIS)

    Upton, A.C.

    1974-01-01

    Although the biological effects of ionizing radiation are probably better known than those of any other physical or chemical agent in the environment, our information about such effects has come from observations at doses and dose rates which are orders of magnitude higher than natural background environmental radiation levels. Whether, therefore biological effects occur in response to such low levels can be estimated only by extrapolation, based on assumptions about the dose-effect relationship and the mechanisms of the effects in question. Present knowledge suggests the possibility that several types of biological effects may result from low-level irradiation. The induction of heritable genetic changes in germ cells and carcinogenic changes in somatic cells are considered to be the most important from the standpoint of their potential threat to health. On the basis of existing data, it is possible to make only tentative upper limit estimates of the risks of these effects at low doses. The estimates imply that the frequency of such effects attributable to exposure at natural background radiation levels would constitute only a small fraction of their natural incidence. 148 references

  4. Genetic Synthesis of New Reversible/Quantum Ternary Comparator

    Directory of Open Access Journals (Sweden)

    DEIBUK, V.

    2015-08-01

    Full Text Available Methods of quantum/reversible logic synthesis are based on the use of the binary nature of quantum computing. However, multiple-valued logic is a promising choice for future quantum computer technology due to a number of advantages over binary circuits. In this paper we have developed a synthesis of ternary reversible circuits based on Muthukrishnan-Stroud gates using a genetic algorithm. The method of coding chromosome is presented, and well-grounded choice of algorithm parameters allowed obtaining better circuit schemes of one- and n-qutrit ternary comparators compared with other methods. These parameters are quantum cost of received reversible devices, delay time and number of constant input (ancilla lines. Proposed implementation of the genetic algorithm has led to reducing of the device delay time and the number of ancilla qutrits to 1 and 2n-1 for one- and n-qutrits full comparators, respectively. For designing of n-qutrit comparator we have introduced a complementary device which compares output functions of 1-qutrit comparators.

  5. Significance of epidemiological studies for estimating the genetic radiation hazards of man

    International Nuclear Information System (INIS)

    Stephan, G.

    1982-01-01

    Following a brief presentation of the fundamentals of epidemiological studies, the problems associated with such studies are discussed. Epidemiological investigations on survivors of the atomic bomb explosions in Hiroshima and Nagasaki and also on the population of Kerala, a state in south west India with a high natural radiation load, are then discussed. Consideration was given to the question whether the Down-Syndrom is a valid indicator for proving a causal relationship between radiation dose and genetic effects. (MG) [de

  6. Chronic radiation exposure as an ecological factor: Hypermethylation and genetic differentiation in irradiated Scots pine populations

    International Nuclear Information System (INIS)

    Volkova, P.Yu.; Geras'kin, S.A.; Horemans, N.; Makarenko, E.S.; Saenen, E.; Duarte, G.T.; Nauts, R.; Bondarenko, V.S.; Jacobs, G.; Voorspoels, S.; Kudin, M.

    2018-01-01

    Genetic and epigenetic changes were investigated in chronically irradiated Scots pine (Pinus sylvestris L.) populations from territories that were heavily contaminated by radionuclides as result of the Chernobyl Nuclear Power Plant accident. In comparison to the reference site, the genetic diversity revealed by electrophoretic mobility of AFLPs was found to be significantly higher at the radioactively contaminated areas. In addition, the genome of pine trees was significantly hypermethylated at 4 of the 7 affected sites. - Highlights: • Chronic radiation exposure changes the genetic structure of plant populations. • Genomes of irradiated pines are hypermethylated. • The level of hypermethylation does not depend on annual dose. - These results indicate that even relatively low levels of chronic radiation exposure can influence on the genetic characteristics and the methylation status of natural pine populations and that it should be considered as an important ecological factor reflecting the anthropogenic impact on ecosystems.

  7. 50. Brazilian congress on genetics. 50 years developing genetics. Abstracts

    International Nuclear Information System (INIS)

    2004-01-01

    Use of radioisotopes and ionizing radiations in genetics is presented. Several aspects related to men, animals,plants and microorganisms are reported highlighting biological radiation effects, evolution, mutagenesis and genetic engineering. Genetic mapping, gene mutations, genetic diversity, DNA damages, plant cultivation and plant grow are studied as well

  8. The effect of dithiothreitol on radiation-induced genetic damage in Arabidopsis thaliana (L) Heynh

    International Nuclear Information System (INIS)

    Dellaert, L.M.W.

    1980-01-01

    A study was made on the effect of dithiothreitol (DTT; present during irradiation) on M 1 ovule sterility, M 2 embryonic lethals, M 2 chlorophyll mutants and M 2 viable mutants induced with fast neutrons or X-rays in Arabidopsis thaliana. DTT provides considerable protection against both fast-neutron and X-ray induced genetic damage. However, a higher protection was observed against M 1 ovule sterility, than against embryonic lethals, chlorophylls and viable mutants. This implies a significant DTT-induced spectral shift (0.01 < p < 0.05), i.e. a shift in the relative frequencies of the different genetic parameters. This spectral shift is explained on the basis of a specific DTT protection against radiation-induced strand breaks, and by differences in the ratio strand breaks/base damage for the genetic parameters concerned, i.e. a higher ratio for ovule sterility than for the other parameters. The induction of the genetic damage by ionizing radiation, either with or without DTT, is described by a mathematical model, which includes both strand breaks and base damage. The model shows that the resolving power of a test for a 'mutation'spectral shift depends on the relative values of the strandbreak reduction factor of -SH compounds and on the ratio strand breaks/base damage of the genetic parameters. For each genetic parameter the DTT damage reduction factor (DRF) is calculated per irradiation dose, and in addition the average (over-all doses) ratio strand breaks/base damage. (orig.)

  9. Comparative riverscape genetics reveals reservoirs of genetic diversity for conservation and restoration of Great Plains fishes.

    Science.gov (United States)

    Osborne, Megan J; Perkin, Joshuah S; Gido, Keith B; Turner, Thomas F

    2014-12-01

    We used comparative landscape genetics to examine the relative roles of historical events, intrinsic traits and landscape factors in determining the distribution of genetic diversity of river fishes across the North American Great Plains. Spatial patterns of diversity were overlaid on a patch-based graphical model and then compared within and among three species that co-occurred across five Great Plains watersheds. Species differing in reproductive strategy (benthic vs. pelagic-spawning) were hypothesized to have different patterns of genetic diversity, but the overriding factor shaping contemporary patterns of diversity was the signature of past climates and geological history. Allelic diversity was significantly higher at southern latitudes for Cyprinella lutrensis and Hybognathus placitus, consistent with northward expansion from southern Pleistocene refugia. Within the historical context, all species exhibited lowered occupancy and abundance in heavily fragmented and drier upstream reaches, particularly H. placitus; a pelagic-spawning species, suggesting rates of extirpation have outpaced losses of genetic diversity in this species. Within most tributary basins, genetically diverse populations of each species persisted. Hence, reconnecting genetically diverse populations with those characterized by reduced diversity (regardless of their position within the riverine network) would provide populations with greater genetic and demographic resilience. We discuss cases where cross-basin transfer may be appropriate to enhance genetic diversity and mitigate negative effects of climate change. Overall, striking similarities in genetic patterns and in response to fragmentation and dewatering suggest a common strategy for genetic resource management in this unique riverine fish assemblage. © 2014 John Wiley & Sons Ltd.

  10. Analysis of potential radiation-induced genetic and somatic effects to man from milling of uranium

    International Nuclear Information System (INIS)

    Momeni, M.H.

    1984-01-01

    Potential mortality from natural causes and from radiation exposure conditions typical of those in the vicinity of uranium mills in the western USA was calculated. The exposure conditions were those assumed to exist in the vicinity of a hypothetical model mill. Dose rates to organs at risk were calculated as a function of time using the Uranium Dispersion and Dosimetry Code (Momeni et al. 1979). The changes in population size, birth rates, and radiation-induced and natural mortalities were calculated using the PRIM code (Momeni 1983). The population of the region within a radius of 80 km from the model mill is projected to increase from 57 428 to 75 638.6 during the 85 years of this analysis. Within the same period, the average birth rates for five-year periods increase from 5067.8 to 7436.1. The cumulative deaths within the five-year periods increase from 724 and 3501.8 from spontaneously induced neoplasms and all causes, respectively, to 1538.2 and 6718.2. In comparison to natural causes, radiation-induced mortality is negligible. The highest rate of death from radiation in any five-year period is only 0.2, compared with 1538.2 deaths attributable to spontaneous incidence. The total radiation-induced genetic disorders were much less than unity for the 85-year period of analysis, in contrast with the 10.7% natural incidence of these disorders

  11. Environmental radiation and exposure to radiation

    International Nuclear Information System (INIS)

    1981-02-01

    Compared to 1977 the exposure to radiation of the population of the Federal Republic of Germany from both natural and artificial radiation sources has not greatly charged. The amin part of exposure to natural radiation is caused by environmental radiation and by the absorption of naturally radioactive substances into the body. Artificial exposure to radiation of the population is essentially caused by the use of ionizing rays and radioactive substances in medicine. When radioactive materials are released from nuclear facilities the exposure to radiation of the population is only very slightly increased. The real exposure to radiation of individual people can even in the worst affected places, have been at most fractions of a millirem. The exposure to radiation in the worst afected places in the area of a hard-coal power station is higher than that coming from a nuclear power station of the same capacity. The summation of all contributions to the exposure of radiation by nuclear facilities to the population led in 1978 in the Federal Republic of Germany to a genetically significant dose of clearly less than 1 millerem per year. The medium-ranged exposure to radiation by external radiation effects through professional work was in 1978 at 80 millirems. No difference to 1977. The contribution of radionuclide from the fallout coming from nuclear-weapon tests and which has been deposited in the soil, to the whole-body dose for 1978 applies the same as the genetically significant dose of the population with less than 1 millirem. (orig./HP) [de

  12. Validation of radiation dose estimations in VRdose: comparing estimated radiation doses with observed radiation doses

    International Nuclear Information System (INIS)

    Nystad, Espen; Sebok, Angelia; Meyer, Geir

    2004-04-01

    The Halden Virtual Reality Centre has developed work-planning software that predicts the radiation exposure of workers in contaminated areas. To validate the accuracy of the predicted radiation dosages, it is necessary to compare predicted doses to actual dosages. During an experimental study conducted at the Halden Boiling Water Reactor (HBWR) hall, the radiation exposure was measured for all participants throughout the test session, ref. HWR-681 [3]. Data from this experimental study have also been used to model tasks in the work-planning software and gather data for predicted radiation exposure. Two different methods were used to predict radiation dosages; one method used all radiation data from all the floor levels in the HBWR (all-data method). The other used only data from the floor level where the task was conducted (isolated data method). The study showed that the all-data method gave predictions that were on average 2.3 times higher than the actual radiation dosages. The isolated-data method gave predictions on average 0.9 times the actual dosages. (Author)

  13. Functional genetic research for radiation and drug resistant adenocarcinoma and its application

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Gyu; Kim, Kug Chan; Jung, Il Lae; Chul, Shin Byung; Kook, Park Hyo; Lee, Hee Min

    2012-01-15

    The work scope of 'Functional genetic research for radiation and drug resistant adenocarcinoma and its application' had contained the research about effect of transgelin(SM22a), neurotensin, metallothionein-1G transgelin-2 genes on the cell death triggered ionizing radiation, cisplatin, MMS, luteolin and H{sub 2}O{sub 2}(toxic agents), which are highly expressed in radiation-induced mutant cells. In this study, to elucidate the role of these proteins in the ionizing radiation (toxic chemicals)-induced cell death, we utilized sensed (or antisense, small interference RNA) cells, which overexpress (or down-regulate) RNAs associated with these proteins biosynthesis, and investigated the effects of these genes on the cytotoxicity caused by ionizing radiation, H{sub 2}O{sub 2} and toxic chemicals. We also investigated the functions of downstream target genes of transgelin such as IGF-1Rβ/PI3K/AKT pathway and transgelin/metallothioneine in A-549 and HepG2 cells because such target genes are able to potentiate the cell-killing or cell protecting effects against radiation.

  14. Functional genetic research for radiation and drug resistant adenocarcinoma and its application

    International Nuclear Information System (INIS)

    Kim, In Gyu; Kim, Kug Chan; Jung, Il Lae; Chul, Shin Byung; Kook, Park Hyo; Lee, Hee Min

    2012-01-01

    The work scope of 'Functional genetic research for radiation and drug resistant adenocarcinoma and its application' had contained the research about effect of transgelin(SM22a), neurotensin, metallothionein-1G transgelin-2 genes on the cell death triggered ionizing radiation, cisplatin, MMS, luteolin and H 2 O 2 (toxic agents), which are highly expressed in radiation-induced mutant cells. In this study, to elucidate the role of these proteins in the ionizing radiation (toxic chemicals)-induced cell death, we utilized sensed (or antisense, small interference RNA) cells, which overexpress (or down-regulate) RNAs associated with these proteins biosynthesis, and investigated the effects of these genes on the cytotoxicity caused by ionizing radiation, H 2 O 2 and toxic chemicals. We also investigated the functions of downstream target genes of transgelin such as IGF-1Rβ/PI3K/AKT pathway and transgelin/metallothioneine in A-549 and HepG2 cells because such target genes are able to potentiate the cell-killing or cell protecting effects against radiation

  15. Estimation of health risks from radiation exposures

    International Nuclear Information System (INIS)

    Randolph, M.L.

    1983-08-01

    An informal presentation is given of the cancer and genetic risks from exposures to ionizing radiations. The risks from plausible radiation exposures are shown to be comparable to other commonly encountered risks

  16. Estimation of health risks from radiation exposures

    Energy Technology Data Exchange (ETDEWEB)

    Randolph, M.L.

    1983-08-01

    An informal presentation is given of the cancer and genetic risks from exposures to ionizing radiations. The risks from plausible radiation exposures are shown to be comparable to other commonly encountered risks.

  17. Genetic determination of the biological radiation response in inbred mice lines; Genetische Determination der biologischen Strahlenantwort in Mausinzuchtstaemmen

    Energy Technology Data Exchange (ETDEWEB)

    Gomolka, M.; Hornhardt, S.; Jung, T. [Bundesamt fuer Strahlenschutz Oberschleissheim (Germany). Institut fuer Strahlenhygiene

    2000-07-01

    Variation in radiation sensitivity and radiation resistance is influenced by the genetic constitution of an individual. Loss of function of genes involved in DNA repair, cell cycle or controlled cell death can have serious consequences on individual radiation sensitivity. For example, individuals suffering on the clinical syndrome of Ataxia telangiectasia exhibit radiation sensitivity in the order of 2-3 magnitudes higher than other cancer patients. For radiation protection it is important to clarify the role of genetic predisposition for radiation sensitivity in clinical healthy people. Therefore, data were collected from the literature describing the genetic variation (heritability) of radiation sensitivity in the mouse model. A heritability of 30-50% was calculated for 27 inbred mice lines by Roderick (1963) based on days of survival after a daily dose of 1 Gy {gamma}-irradiation. The following inbred lines were described in the literature as radiation sensitive (phenotypical markers were e.g., time of survival, mortality, reduction in fertility post exposure): SWR, RIII, NC, K, HLG, DBA, CBA, BALB/c, A, AKR. Radiation resistance was demonstrated in SJL, SEC, RF, MA, C58, C57BR, BDP and 129. Parameter of longevity, some physiological, biochemical and immunological parameters as given in the data bank of the Jackson Laboratory, U.S.A., were compared between radiation sensitive and radiation resistant inbred strains. No correlation was seen for the most of the parameters except for the development of breast cancer. In 6 out of 10 radiosensitive inbred strains breast cancer is described while only 1 of 8 strains exhibits breast cancer. The higher heritability of 30-50% in spite of a very complex phenotype like survival and the correlation between radiosensitivity and tumour incidence show that individual genetic susceptibility is important on the biological radiation reaction. (orig.) [German] Die phaenotypische Variation der Strahlensensitivitaet und

  18. A comparative phylogenetic study of genetics and folk music.

    Science.gov (United States)

    Pamjav, Horolma; Juhász, Zoltán; Zalán, Andrea; Németh, Endre; Damdin, Bayarlkhagva

    2012-04-01

    Computer-aided comparison of folk music from different nations is one of the newest research areas. We were intrigued to have identified some important similarities between phylogenetic studies and modern folk music. First of all, both of them use similar concepts and representation tools such as multidimensional scaling for modelling relationship between populations. This gave us the idea to investigate whether these connections are merely accidental or if they mirror population migrations from the past. We raised the question; does the complex structure of musical connections display a clear picture and can this system be interpreted by the genetic analysis? This study is the first to systematically investigate the incidental genetic background of the folk music context between different populations. Paternal (42 populations) and maternal lineages (56 populations) were compared based on Fst genetic distances of the Y chromosomal and mtDNA haplogroup frequencies. To test this hypothesis, the corresponding musical cultures were also compared using an automatic overlap analysis of parallel melody styles for 31 Eurasian nations. We found that close musical relations of populations indicate close genetic distances (music; maternal lineages have a more important role in folk music traditions than paternal lineages. Furthermore, the combination of these disciplines establishing a new interdisciplinary research field of "music-genetics" can be an efficient tool to get a more comprehensive picture on the complex behaviour of populations in prehistoric time.

  19. A Kantian argument against comparatively advantageous genetic modification.

    Science.gov (United States)

    Jensen, David

    2011-08-01

    The genetic modification of children is becoming a more likely possibility given our rapid progress in medical technologies. I argue, from a broadly Kantian point of view, that at least one kind of such modification-modification by a parent for the sake of a child's comparative advantage-is not rationally justified. To argue this, I first characterize a necessary condition on reasons and rational justification: what is a reason for an agent to do an action in one set of circumstances must be a reason for any in those circumstances to do the action. I then show that comparatively advantageous genetic modification violates this principle since a child's "getting ahead" through genetic modification cannot be rationally justified unless other children also could receive the modification, thus rendering the advantage useless. Finally, I consider the major objection to this it seems to disallow all cases of a parent's helping a child get ahead, something that parents normally engage in with their children. I argue that typical practices of developing a comparative advantage in a child, as well as practices of societal competition in general, do not conflict because they involve circumstances that mitigate the universal character of reasons. Many ordinary cases of competitive advantage that we think of as unjust, in fact, can be explained by my argument.

  20. AGN Feedback Compared: Jets versus Radiation

    Science.gov (United States)

    Cielo, Salvatore; Bieri, Rebekka; Volonteri, Marta; Wagner, Alexander Y.; Dubois, Yohan

    2018-03-01

    Feedback by Active Galactic Nuclei is often divided into quasar and radio mode, powered by radiation or radio jets, respectively. Both are fundamental in galaxy evolution, especially in late-type galaxies, as shown by cosmological simulations and observations of jet-ISM interactions in these systems. We compare AGN feedback by radiation and by collimated jets through a suite of simulations, in which a central AGN interacts with a clumpy, fractal galactic disc. We test AGN of 1043 and 1046 erg/s, considering jets perpendicular or parallel to the disc. Mechanical jets drive the more powerful outflows, exhibiting stronger mass and momentum coupling with the dense gas, while radiation heats and rarifies the gas more. Radiation and perpendicular jets evolve to be quite similar in outflow properties and effect on the cold ISM, while inclined jets interact more efficiently with all the disc gas, removing the densest 20% in 20 Myr, and thereby reducing the amount of cold gas available for star formation. All simulations show small-scale inflows of 0.01 - 0.1 M⊙/yr, which can easily reach down to the Bondi radius of the central supermassive black hole (especially for radiation and perpendicular jets), implying that AGN modulate their own duty cycle in a feedback/feeding cycle.

  1. Protection against genetic hazards from environmental chemical mutagens: experience with ionizing radiation

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1977-01-01

    In radiation protection, the recurrent theme is, and always has been, dose limitation whether it is for occupational workers, individual members of the public or the population as a whole. The key words are 'dose' and 'limitation'. The quantitative system of dose limitation has been achieved because of a number of conceptual developments in our understanding of the mechanism of radiation action, development of radiation dosimetry, the accumulation of a vast body of quantitative information on dose-effect relationships and the effects of various biological and physical variables that affect these relationships of data on patterns and levels of exposures likely to be encountered to make estimates of the effects expected to result from such exposures, and balancing of risks to society against the benefits derived, the latter a matter of informed judgement. The philosophy has always been to avoid all unnecessary exposures and to limit the necessary exposures (justified by the benefits expected) to as low a level as reasonably achievable, social and economic factors being taken into acccount. The introduction of the concept that the system of dose limitation to the population should be based on genetic risks has stressed the need for careful planning to ensure that our genetic heritage is not endangered. Transfer of this knowledge to the field of chemical protection is discussed. (Auth.)

  2. Abstracts of the 48. Brazilian congress on genetics. Genetics in social inclusion

    International Nuclear Information System (INIS)

    2002-01-01

    Use of radioisotopes and ionizing radiations in genetics is presented. Several aspects related to men, animals, plants and microorganisms are reported highlighting biological radiation effects, evolution, mutagenesis and genetic engineering. Genetic mapping, polymerase chain reaction, gene mutations, genetic diversity, DNA hybridization, DNA sequencing, plant cultivation and plant grow are studied as well

  3. AGN feedback compared: jets versus radiation

    Science.gov (United States)

    Cielo, Salvatore; Bieri, Rebekka; Volonteri, Marta; Wagner, Alexander Y.; Dubois, Yohan

    2018-06-01

    Feedback by active galactic nuclei (AGNs) is often divided into quasar and radio mode, powered by radiation or radio jets, respectively. Both are fundamental in galaxy evolution, especially in late-type galaxies, as shown by cosmological simulations and observations of jet-ISM (interstellar medium) interactions in these systems. We compare AGN feedback by radiation and by collimated jets through a suite of simulations, in which a central AGN interacts with a clumpy, fractal galactic disc. We test AGNs of 1043 and 1046 erg s-1, considering jets perpendicular or parallel to the disc. Mechanical jets drive the more powerful outflows, exhibiting stronger mass and momentum coupling with the dense gas, while radiation heats and rarefies the gas more. Radiation and perpendicular jets evolve to be quite similar in outflow properties and effect on the cold ISM, while inclined jets interact more efficiently with all the disc gas, removing the densest 20 {per cent} in 20 Myr, and thereby reducing the amount of cold gas available for star formation. All simulations show small-scale inflows of 0.01-0.1 M⊙ yr-1, which can easily reach down to the Bondi radius of the central supermassive black hole (especially for radiation and perpendicular jets), implying that AGNs modulate their own duty cycle in a feedback/feeding cycle.

  4. The biological effects of radiation

    International Nuclear Information System (INIS)

    Sykes, D.A.

    1979-01-01

    The hazards of radiations to man are briefly covered in this paper. The natural background sources of radiations are stated and their resulting doses are compared to those received voluntarily by man. The basis of how radiations cause biological damage is given and the resulting somatic effects are shown for varying magnitude of dose. Risk estimates are given for cancer induction and genetic effects are briefly discussed. Finally four case studies of radiation damage to humans are examined exemplifying the symptoms of large doses of radiations [af

  5. Ionizing radiation, radiation sources, radiation exposure, radiation effects. Pt. 2

    International Nuclear Information System (INIS)

    Schultz, E.

    1985-01-01

    Part 2 deals with radiation exposure due to artificial radiation sources. The article describes X-ray diagnosis complete with an analysis of major methods, nuclear-medical diagnosis, percutaneous radiation therapy, isotope therapy, radiation from industrial generation of nucler energy and other sources of ionizing radiation. In conclusion, the authors attempt to asses total dose, genetically significant dose and various hazards of total radiation exposure by means of a summation of all radiation impacts. (orig./WU) [de

  6. Assessment of genetic risk for human exposure to radiation. State of the art

    International Nuclear Information System (INIS)

    Shevchenko, V.A.

    2000-01-01

    Historical aspects of the conception of genetic risk of human irradiation for recent 40 years. Methodology of assessing the genetic risk of radiation exposure is based on the concept of hitting the target. To predict genetic risk of irradiation, the direct and indirect methods of assessment, extrapolation, integral and populational criteria of risk analysis is widely used. Combination of these methods permits to calculate the risk from human exposure on the basis of data obtained for mice. Method of doubling dose based on determination of the dose doubling the level of natural mutational process in humans is the main one used to predict the genetic risk. Till 1972 the main model for assessing the genetic risk was the human/mouse model (the use of data on the spontaneous human variability and data on the frequency of induced mutations in mice). In the period from 1972 till 1994 the mouse/mouse model was intensively elaborated in many laboratories. This model was also used in this period to analyse the genetic risk of human irradiation. Recent achievements associated with the study of molecular nature of many hereditary human diseases as well as the criticism of a fundamental principles of the mouse/mouse model for estimating the genetic risk on a new basis. Estimates of risk for the different classes of genetic diseases have been obtained using the doubling-dose method [ru

  7. Measurement of Global Solar Radiation data using Raspberry Pi and its estimation using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Priya S.Shanmuga

    2018-01-01

    Full Text Available The demand for more efficient and environmentally benign, non-conventional sources of energy came into picture due to increasing demands for human comforts. Solar energy is now the ultimate option. In this paper, the instruments used to measure the solar radiation at Innovation Centre, MIT Manipal were connected to a Raspberry Pi to access the data remotely. Genetic Algorithms were formulated, so that the monthly mean global solar radiation in Manipal can be effectively estimated. Meteorological data such as humidity, temperature, wind speed, etc. were used as inputs to train the networks. A successful network was made between the data loggers and the Raspberry Pi. The data collected by the data loggers from the devices are transmitted to the Raspberry Pi which in turn sends the data to an internal server. The Raspberry Pi can be accessed using any SSH client such as PuTTY. The meteorological data was collected for the years 2010-2014 in order to formulate the Artificial Intelligence models. The validity of the formulated models were checked by comparing the measured data with the estimated data using tools such as RMSE, correlation coefficient, etc. The modelling of solar radiation using GA was carried out in GeneXpro tools version 5.0.

  8. Ecological-genetic aspects of consequences of an irradiation at the workers of a nuclear industry

    International Nuclear Information System (INIS)

    Telnov, V.I.

    2000-01-01

    The urgent problem of genetic consequences of radiation exposure at the workers of atomic plant ''Mayak'' is considered. Two basic aspects of this problem are allocated: influences of radiation on hereditary structures and processes, which is a prerogative of radiation genetics and role of the genetic factors in different reactions to an irradiation, that is a task of ecology genetics, which recently receives the increasing recognition. Proceeding from distinctions in reproduction biology of the human and experimental biological objects determining non-comparable mutation risk at them, is recognized expedient to expand a spectrum of genetic researches in the irradiated people. The results of different genetic researches in total in 2811 peoples executed in view of two named aspects discussed. At radiation-genetic investigation of distribution of genetic polymorphism system (haptoglobin -Hp, Gc-protein -Gc and blood groups ABO) the certain changes in distribution of Hp types and alleles of children of the irradiated workers connected with a gonad external gamma-radiation doses are established. The genetic structure of the grandsons of the irradiated workers has not any deviations. The increase of mutation frequency in minisatellite DNA in germline cells of irradiate workers was not found out. At ecological-genetic investigation the important meaning of haptoglobin genetic system in different radiation resistance of the people established at study of a role of a number of the genetic polymorphism systems (Hp, Gc and ABO) in radiation effects at different levels of biological organization. The integrated estimation of role of Hp genotypes in observable radiation effects carried out. (author)

  9. Individual radiation sensitivity (gender, age, genetic disposition). Consequences for radiation protection

    International Nuclear Information System (INIS)

    Streffer, C.

    2013-01-01

    The effects of ionising radiation on human health is influenced by a number of physiological and molecular biological factors. This is also valid for the causation of stochastic radiation effects especially the causation of cancer. Several epidemiological studies have resulted with respect to the total rate of solid cancers that women are more sensitive than men by a factor of 1.6 to 2.0. For leukaemia this is not the case. The largest studies come from the investigations on the survivors of the atomic bombs in Hiroshima and Nagasaki. But also studies on the population of the Techa River (Southeast Urals) yield such data. The analyses of single cancer localizations come to different results with respect to the dependence on the sex. Secondary cancers after radiotherapy for cancer treatment show also higher rates in women than in men. A similar situation is observed with respect to the dependence of cancer rate on age. The total rate of solid cancers is highest with children and decreases with increasing age. The effects are very different again with single cancer localizations. An especially strong age dependence was observed for thyroid cancer. Increasingly individuals have been found who are especially radiosensitive on the basis of their genetic disposition also with respect to the causation of cancer. Mechanisms and possibilities to trace these individuals are discussed. It is also discussed whether and to which extent these data should have consequences for the practical radiological protection. (orig.)

  10. [Ionizing and non-ionizing radiation (comparative risk estimations)].

    Science.gov (United States)

    Grigor'ev, Iu G

    2012-01-01

    The population has widely used mobile communication for already more than 15 years. It is important to note that the use of mobile communication has sharply changed the conditions of daily exposure of the population to EME We expose our brain daily for the first time in the entire civilization. The mobile phone is an open and uncontrollable source of electromagnetic radiation. The comparative risk estimation for the population of ionizing and non-ionizing radiation was carried out taking into account the real conditions of influence. Comparison of risks for the population of ionizing and non-ionizing radiation leads us to a conclusion that EMF RF exposure in conditions of wide use of mobile communication is potentially more harmful than ionizing radiation influence.

  11. Monitoring the genetic health of persons in Goiania accidentally exposed to ionizing radiation from caesium-137

    International Nuclear Information System (INIS)

    Da Cruz, A.D.; Glickman, B.W.

    1998-01-01

    This work describes the long term genetic monitoring of the Goiania population exposed to ionizing radiation from 137 Cs, using cytogenetic and molecular endpoints. Cytogenetically, micronucleus frequencies differentiated groups exposed to different levels of radiation. Two molecular methods were employed: 1) the hprt clonal assay, involving in vitro selection of 6-thioguanine-resistant hprt mutant clones which were characterized at the molecular level using RT-PCR and genomic analysis. Ionizing radiation exposure initially elevated hprt mutation frequency which gradually diminished, so that no significant increase was observed four and a half years after original exposure. The spectrum of hprt mutations recovered from ten individuals exposed to relatively high doses of radiation revealed a fourfold increase in the frequency of A:T → G:C transitions. The increase is consistent with the effects of ionizing radiation in prokaryotes and lower eukaryotes. Additionally, a twofold increase in the frequency of deletions was observed which may reflect radiation induced DNA strand breakage; 2) determination of microsatellite instability using fluorescent PCR and genomic DNA from mononuclear cells. The frequency distributions of somatic microsatellite alterations in exposed and non-exposed populations were not different. Our assay lacked sensitivity to discriminate between spontaneous and induced microsatellite instability and therefore, is not suitable for population monitoring. Finally, we estimated the risk associated with radiation exposure for the exposed Goiania population. The estimated genetic risk of dominant disorders in the first post-exposure generation was increased nearly twenty-fourfold. The risk of carcinogenesis was increased by a factor of 1.5. (author)

  12. Monitoring the genetic health of persons in Goiania accidentally exposed to ionizing radiation from caesium-137

    Energy Technology Data Exchange (ETDEWEB)

    Da Cruz, A D; Glickman, B W [Centre for Environmental Health, Department of Biology, University of Victoria, Victoria, BC (Canada)

    1998-12-01

    This work describes the long term genetic monitoring of the Goiania population exposed to ionizing radiation from {sup 137}Cs, using cytogenetic and molecular endpoints. Cytogenetically, micronucleus frequencies differentiated groups exposed to different levels of radiation. Two molecular methods were employed: (1) the hprt clonal assay, involving in vitro selection of 6-thioguanine-resistant hprt mutant clones which were characterized at the molecular level using RT-PCR and genomic analysis. Ionizing radiation exposure initially elevated hprt mutation frequency which gradually diminished, so that no significant increase was observed four and a half years after original exposure. The spectrum of hprt mutations recovered from ten individuals exposed to relatively high doses of radiation revealed a fourfold increase in the frequency of A:T {yields} G:C transitions. The increase is consistent with the effects of ionizing radiation in prokaryotes and lower eukaryotes. Additionally, a twofold increase in the frequency of deletions was observed which may reflect radiation induced DNA strand breakage; (2) determination of microsatellite instability using fluorescent PCR and genomic DNA from mononuclear cells. The frequency distributions of somatic microsatellite alterations in exposed and non-exposed populations were not different. Our assay lacked sensitivity to discriminate between spontaneous and induced microsatellite instability and therefore, is not suitable for population monitoring. Finally, we estimated the risk associated with radiation exposure for the exposed Goiania population. The estimated genetic risk of dominant disorders in the first post-exposure generation was increased nearly twenty-fourfold. The risk of carcinogenesis was increased by a factor of 1.5. (author)

  13. Studies on the application of radiation for genetic transformation in higher plants

    International Nuclear Information System (INIS)

    Lee, Young Il; Song, Hi Sup; Kim, Jae Sung; Shin, In Chul; Lee, Sang Jae; Lee, Ki Woon; Lim, Yong Taek

    1992-02-01

    Present research carried out to develop the radiation application on the mutation research of genetic engineering. Some variants selected in M1 generation derived from the plantlet by the nodal stem culture of three potato cultivars irradiated with gamma rays, and the optimum dosage for mutation induction was revealed the range of 30 - 50 Gy of gamma ray. In the rice anther culture of the plant irradiated with gamma rays at different developmental stage of microspore, the haploidy callus formation rates were much higher in gamma ray irradiated anthers than those of non-irradiated, and the occurrence of a typical pollen was significantly increased up to 47% in the anthers irradiated with 30 Gy of gamma ray compared with 11% of non-irradiated anthers at the stage of pollen mother cell. A lot of variants were selected in rice, soybean, perilla and red pepper irradiated with gamma rays for breeding of earliness, short culm, high yielding and disease resistant mutant. (Author)

  14. Specific-locus mutation frequencies in mouse stem-cell spermatogonia at very low radiation dose rates, and their use in the estimation of genetic hazards of radiation in man

    International Nuclear Information System (INIS)

    Russell, W.L.; Kelly, E.M.

    1982-01-01

    Experiments were undertaken to augment the information on the lowest radiation dose rates feasible for scoring transmitted induced mutations detected by the specific-locus method in the mouse. This is the type of information most suitable for estimating genetic hazards of radiation in man. The results also aid in resolving conflicting possibilities about the relationship between mutation frequency and radiation dose at low dose rates

  15. Use of PRIM code to analyze potential radiation-induced genetic and somatic effects to man from Jackpile-Paguate mines

    International Nuclear Information System (INIS)

    Momeni, M.H.

    1983-01-01

    Potential radiation-induced effects from inhalation and ingestion of land external exposure to radioactive materials at the Jackpile-Paguate uranium mine complex near Paguate, New Mexico, were analyzed. The Uranium Dispersion and Dosimetry (UDAD) computer code developed at Argonne National Laboratory was used to calculate the dose rates and the time-integrated doses to tissues at risk as a function of age and time for the population within 80 km of the mines. The ANL computer code Potential Radiation-Induced Biological Effects on Man (PRIM) then was used to calculate the potential radiation-induced somatic and genetic effects among the same population on the basis of absolute and relative risk models as a function of duration of exposure and age at time of exposure. The analyses were based on the recommendations in BEIR II and WASH-1400 and the lifetable method. The death rates were calculated for radiation exposure from the mines and for naturally induced effects for 19 age cohorts, 20 time intervals, and for each sex. The results indicated that under present conditions of the radiation environment at the mines, the number of potential fatal radiation-induced neoplasms that could occur among the regional population over the next 85 years would be 95 using the absolute risk model, and 243 using the relative risk model. Over the same period, there would be less than two radiation-induced genetic effects (dominant and multifactorials). After decommissioning f the mine site, these risks would decrease to less than 1 and less than 3 potential radiation-induced deaths under the relative and absolute risk models, respectively, and 0.001 genetic disorders. Because of various sources of error, the uncertainty in these predicted risks could be a factor of five

  16. Genetic diversity, classification and comparative study on the larval ...

    African Journals Online (AJOL)

    Genetic diversity, classification and comparative study on the larval phenotypic ... B. mori showed different performance based on larval phenotypic data. The analysis of variance regarding the studied traits showed that different strains have ...

  17. Genetic signatures from amplification profiles characterize DNA mutation in somatic and radiation-induced sports of chrysanthemum

    International Nuclear Information System (INIS)

    Trigiano, R.N.; Scott, M.C.; Caetano-Anolles, G.

    1998-01-01

    The chrysanthemum (Dendranthema grandiflora Tzvelev.) cultivars 'Dark Charm', 'Salmon Charm', 'Coral Charm' and 'Dark Bronze Charm' are either radiation-induced mutants or spontaneous sports of 'Charm' and constitute a family or series of plants that primarily differ in flower color. These cultivars, which were difficult to differentiate genetically by DNA amplification fingerprinting (DAF), were easily identified by using arbitrary signatures from amplification profiles (ASAP). Genomic DNA was first amplified with three standard octamer arbitrary primers, all of which produced monomorphic profiles. Products from each of these DNA fingerprints were subsequently reamplified using four minihairpin decamer primers. The 12 primer combinations produced signatures containing approximately 37% polymorphic character loci, which were used to estimate genetic relationships between cultivars. Forty-six (32%) unique amplification products were associated with individual cultivars. The number of ASAP polymorphisms detected provided an estimate of the mutation rate in the mutant cultivars, ranging from 0.03% to 1.6% of nucleotide changes within an average of 18 kb of arbitrary amplified DAF sequence. The ASAP technique permits the clear genetic identification of somatic mutants and radiation-induced sports that are genetically highly homogeneous and should facilitate marker assisted breeding and protection of plant breeders rights of varieties or cultivars

  18. Radiation protection in space

    Energy Technology Data Exchange (ETDEWEB)

    Blakely, E.A. [Lawrence Berkeley Lab., CA (United States); Fry, R.J.M. [Oak Ridge National Lab., TN (United States)

    1995-02-01

    The challenge for planning radiation protection in space is to estimate the risk of events of low probability after low levels of irradiation. This work has revealed many gaps in the present state of knowledge that require further study. Despite investigations of several irradiated populations, the atomic-bomb survivors remain the primary basis for estimating the risk of ionizing radiation. Compared to previous estimates, two new independent evaluations of available information indicate a significantly greater risk of stochastic effects of radiation (cancer and genetic effects) by about a factor of three for radiation workers. This paper presents a brief historical perspective of the international effort to assure radiation protection in space.

  19. Radiation protection in space

    International Nuclear Information System (INIS)

    Blakely, E.A.; Fry, R.J.M.

    1995-01-01

    The challenge for planning radiation protection in space is to estimate the risk of events of low probability after low levels of irradiation. This work has revealed many gaps in the present state of knowledge that require further study. Despite investigations of several irradiated populations, the atomic-bomb survivors remain the primary basis for estimating the risk of ionizing radiation. Compared to previous estimates, two new independent evaluations of available information indicate a significantly greater risk of stochastic effects of radiation (cancer and genetic effects) by about a factor of three for radiation workers. This paper presents a brief historical perspective of the international effort to assure radiation protection in space

  20. Tradescantia in studies of genetic effects of low level radiation

    International Nuclear Information System (INIS)

    Yamashita, Atsushi

    1976-01-01

    Tradescantia in studies on genetic effects of low level radiation is briefly introduced. Radiosensitivity, method of screening stamen hair mutation, materials in current uses, spontaneous mutation rate, and modifying factors are refered. For stamen hair mutation b values in exponential model were lower in irradiation with low dose rate at high environmental temperature. The dose response curves under these modifying conditions, when extrapolated to low dose range, well fit to the line which was obtained by Sparrow's experiment of low level irradiation. In chronic irradiation, the frequency of stamen hair mutation reaches to the constant value after 17 days from the start of irradiation, and is as much as 4 times higher than the peak value in one day irradiation at the same exposure rate. The spontaneous mutation rate of KU-7 varied with temperature. The increase with 1 0 C increment of mean temperature was -0.04%. Uses of Tradescantia in monitoring the environmental radiation is discussed. (auth.)

  1. Radiation polluton and cancer: comparative risks and proof

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1982-01-01

    A case study of the comparative risks from nuclear radiation and coal burning is presented for a given level of energy production. Mr. Cohen indicates results that might be realized under judicial reforms. Cohen notes the typical overstatement of health hazards from low-level radiation, when current risk assessment methodology derives it from high-level radiation statistics. However, he sees public attention focused on the danger of even low-level radiation brought about by radioactive waste disposal uncertainties. Cohen accuses the information media of generating bad news even when facts point in the opposite direction. He offers as an example, a rationale for the Best-Collins proposal to adjudicate pollution engendered torts under the guidance of reputable authorities rather than impressionable juries guided by proximate case. The paper ends with the question, How can the ajudication system be reformed, given such perverse incentives

  2. Correlation and regression analyses of genetic effects for different types of cells in mammals under radiation and chemical treatment

    International Nuclear Information System (INIS)

    Slutskaya, N.G.; Mosseh, I.B.

    2006-01-01

    Data about genetic mutations under radiation and chemical treatment for different types of cells have been analyzed with correlation and regression analyses. Linear correlation between different genetic effects in sex cells and somatic cells have found. The results may be extrapolated on sex cells of human and mammals. (authors)

  3. A search for genetic effects of atomic bomb radiation on the growth and development of the F1 generation, 1

    International Nuclear Information System (INIS)

    Furusho, Toshiyuki; Otake, Masanori.

    1978-10-01

    In a search for possible genetic effects of atomic bomb radiation on the growth and development of offspring of A-bomb survivors a survey was made in 1965 on approximately 200,000 children of all primary schools, junior high schools, and senior high schools in the cities of Hiroshima and Nagasaki. Of the collected data, those pertaining to senior high school students 15 to 17 years of age of Hiroshima City were analyzed to determine if there was any genetic effect of A-bomb radiation on stature. Comparisons were made with regard to the mean stature and variance of the offspring and the covariance and correlation between one parent or the sum for both parents and offspring for the exposed group and the nonexposed group. The observed differences included those with both positive and negative signs, but none were statistically significant nor did they demonstrate any specific tendency. A comparison was made with a similar study reported by Neel and Schull. Furthermore, estimation of the regression coefficients of the mean stature, variance, covariance, and correlation between one parent or the sum for both parents and offspring by parental radiation dose also did not show any specific tendency. Though the genetic effects of A-bomb radiation on stature could not be accurately estimated in the current series of analyses, the stature data of 6- to 14-year-old children in Hiroshima and those of 6- to 17-year-old children in Nagasaki Will soon be studied, which should permit a more comprehensive and extensive analysis and evaluation of the possible genetic effects of radiation on stature. (author)

  4. Recent advances in the estimation of genetic risks of exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    2002-01-01

    This paper reviews the major advances that have occurred during the last few years in the estimation of genetic risks of exposure of human populations to ionizing radiation. Among these are: (i) an upward revision of the estimates of the baseline frequencies of Mendelian diseases (from 1.25% to 2.4%); (ii) the conceptual change to the use of a doubling dose based on human data on spontaneous mutation rates and mouse data on induced mutation rates (from the one based entirely on mouse data on spontaneous and induced mutation rates, which was the case thus far); (iii) the fuller development of the concept of mutation component (MC) and its application to predict the responsiveness of Mendelian and chronic multi factorial diseases to induced mutations; (iv) the introduction of the concept that the major adverse effects of radiation exposure of human germ cells are likely to be manifest as multi-system developmental abnormalities and (v) the introduction of concept of potential recoverability correction factor (PRCF) to bridge the gap between induced mutations studied in mice and the risk of genetic disease in humans are reviewed

  5. Monitoring the genetic health of humans accidentally exposed to ionizing radiation of Cesium-137 in Goiania (Brazil)

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, A. da; Glickman, B.W. [Victoria Univ., BC (Canada). Dept. of Biology. Centre for Environmental Health

    1997-12-31

    A long-term genetic monitoring of the Goiania population exposed to ionizing radiation of Cesium-137 is described using cytogenetic and molecular endpoints. Two molecular methods were employed: the hprt clonal assay, involving in vitro selection of 6-thioguanine-resistant hprt mutant clones which were characterized at the molecular level using RT-PCR and genomic analysis. Ionizing radiation exposure initially elevated hprt mutation frequency which gradually diminished, so that no significant increase was observed 4.5 years after original exposure. The spectrum of hprt mutation recovered from 10 individuals exposed to relatively high doses of radiation revealed a 4-fold increase in the frequency of A:T{yields}G:C transitions. Additionally, a two-fold increase in the frequency of deletions was observed which may reflect radiation-induced DNA strand breakage; determination of micro satellite instability using fluorescent PCR and genomic DNA from mononuclear cells. The frequency distribution of somatic micro satellite alterations in exposed and non-exposed populations were not different. We estimated the risk associated with radiation exposure for the exposed Goiania population. The estimated genetic risk of dominant disorders in the first post-exposure generation was increased by approximately a 24-fold. The risk of carcinogenesis was increased by a factor of 1.5 13 refs.; e-mail: acruz at uvic.ca.; bwglick at uvic.ca

  6. Cyanobacteria: photosynthetic factories combining biodiversity, radiation resistance, and genetics to facilitate drug discovery.

    Science.gov (United States)

    Cassier-Chauvat, Corinne; Dive, Vincent; Chauvat, Franck

    2017-02-01

    Cyanobacteria are ancient, abundant, and widely diverse photosynthetic prokaryotes, which are viewed as promising cell factories for the ecologically responsible production of chemicals. Natural cyanobacteria synthesize a vast array of biologically active (secondary) metabolites with great potential for human health, while a few genetic models can be engineered for the (low level) production of biofuels. Recently, genome sequencing and mining has revealed that natural cyanobacteria have the capacity to produce many more secondary metabolites than have been characterized. The corresponding panoply of enzymes (polyketide synthases and non-ribosomal peptide synthases) of interest for synthetic biology can still be increased through gene manipulations with the tools available for the few genetically manipulable strains. In this review, we propose to exploit the metabolic diversity and radiation resistance of cyanobacteria, and when required the genetics of model strains, for the production and radioactive ( 14 C) labeling of bioactive products, in order to facilitate the screening for new drugs.

  7. Abstracts of the 47. Brazilian congress on genetics. Genetics in the 21st century: challenges

    International Nuclear Information System (INIS)

    2001-01-01

    Use of radioisotopes and ionizing radiations in genetics is presented. Several aspects related to men, animals,plants and microorganisms are reported highlighting evolution, mutagenesis and genetic engineering. Genetic mapping, polymerase chain reaction, gene mutations, genetic diversity, DNA hybridization, DNA sequencing, use of radioisotopes in diagnosis, plant cultivation, plant improvement and effects of ionizing radiations on plant grow are studied as well

  8. Application of radiation-induced apoptosis in radiation oncology and radiation protection

    International Nuclear Information System (INIS)

    Crompton, N.E.A.; Emery, G.C.; Ozsahin, M.; Menz, R.; Knesplova, L.; Larsson, B.

    1997-01-01

    A rapid assay of the ability of lymphocytes to respond to radiation-induced damage is presented. Age and genetic dependence of radiation response have been quantified. The assay is sensitive to low doses of radiation. Its ability to assess the cytotoxic response of blood capillaries to radiation has been evaluated. (author)

  9. Identifying genetic signatures of selection in a non-model species, alpine gentian (Gentiana nivalis L.), using a landscape genetic approach

    DEFF Research Database (Denmark)

    Bothwell, H.; Bisbing, S.; Therkildsen, Nina Overgaard

    2013-01-01

    It is generally accepted that most plant populations are locally adapted. Yet, understanding how environmental forces give rise to adaptive genetic variation is a challenge in conservation genetics and crucial to the preservation of species under rapidly changing climatic conditions. Environmental...... loci, we compared outlier locus detection methods with a recently-developed landscape genetic approach. We analyzed 157 loci from samples of the alpine herb Gentiana nivalis collected across the European Alps. Principle coordinates of neighbor matrices (PCNM), eigenvectors that quantify multi...... variables identified eight more potentially adaptive loci than models run without spatial variables. 3) When compared to outlier detection methods, the landscape genetic approach detected four of the same loci plus 11 additional loci. 4) Temperature, precipitation, and solar radiation were the three major...

  10. Evaluation and re-evaluation of genetic radiation hazards in man

    International Nuclear Information System (INIS)

    Schalet, A.P.; Sankaranarayanan, K.

    1976-01-01

    A detailed presentation is made of the experimental data from the various systems used by Abrahamson to conclude that the per locus per rad (low LET) radiation-induced forward mutation rates in organisms whose DNA content varies by a factor of about 1000, is proportional to genome size. Additional information pertinent in this context is also reviewed. It is emphasized that the mutation rates cited by Abrahamson, although considered as pertaining to mutations at specific loci, actually derive from a broad variety of genetic end-points. It is argued that an initial (if not sufficient) condition for sound interspecific mutation rate comparisons, covering a wide range of organisms and detecting systems of various sensitivities, requires a reasonably consistent biological definition of a specific locus mutation, namely, a transmissible intralocus change. Granting the differences between systems in their resolving power to detect intergenic change, the data cited in this paper do not support the existence of a simple proportionality between radiation-induced intralocus mutation rate and genome size for the different species reviewed here

  11. A search for genetic effects of atomic bomb radiation on the growth and development of the F1 generation, 2

    International Nuclear Information System (INIS)

    Furusho, Toshiyuki; Otake, Masanori.

    1978-08-01

    A comparative study to detect possible genetic effects of atomic bomb radiation on the growth and development of offspring of A-bomb survivors was made on a group of senior high school students 15 to 17 years of age born to survivors and to nonexposed parents in Hiroshima using as variables weight, sitting height, and chest circumference. Using data from students born to nonexposed parents, regression analysis was made to determine the effect of parental age on the weight, sitting height, and chest circumference of the offspring, but no statistically significant relation was observed. The mean and variance values of weight, sitting height, and chest circumference of offspring of nonexposed parents were compared to those of offspring born to exposed father and nonexposed mother, and of offspring born to exposed mother and nonexposed father, but very few statistically significant differences were found. The mean and variance values of weight, sitting height, and chest circumference of offspring born to nonexposed parents were compared to those of offspring born to parents both exposed, and again there were very few statistically significant differences. No specific tendency was observed in relation to the combined radiation dose of both parents. (author)

  12. In Vitro Studies on Space Radiation-Induced Delayed Genetic Responses: Shielding Effects

    Science.gov (United States)

    Kadhim, Munira A.; Green, Lora M.; Gridley, Daila S.; Murray, Deborah K.; Tran, Da Thao; Andres, Melba; Pocock, Debbie; Macdonald, Denise; Goodhead, Dudley T.; Moyers, Michael F.

    2003-01-01

    Understanding the radiation risks involved in spaceflight is of considerable importance, especially with the long-term occupation of ISS and the planned crewed exploration missions. Several independent causes may contribute to the overall risk to astronauts exposed to the complex space environment, such as exposure to GCR as well as SPES. Protons and high-Z energetic particles comprise the GCR spectrum and may exert considerable biological effects even at low fluence. There are also considerable uncertainties associated with secondary particle effects (e.g. HZE fragments, neutrons etc.). The interaction of protons and high-LET particles with biological materials at all levels of biological organization needs to be investigated fully in order to establish a scientific basis for risk assessment. The results of these types of investigation will foster the development of appropriately directed countermeasures. In this study, we compared the biological responses to proton irradiation presented to the target cells as a monoenergetic beam of particles of complex composition delivered to cells outside or inside a tissue phantom head placed in the United States EVA space suit helmet. Measurements of chromosome aberrations, apoptosis, and the induction of key proteins were made in bone marrow from CBA/CaJ and C57BL/6 mice at early and late times post exposure to radiation at 0, 0.5, 1 and 2 Gy while inside or outside of the helmet. The data showed that proton irradiation induced transmissible chromosomal/genomic instability in haematopoietic stem cells in both strains of mice under both irradiation conditions and especially at low doses. Although differences were noted between the mouse strains in the degree and kinetics of transforming growth factor-beta 1 and tumor necrosis factor-alpha secretion, there were no significant differences observed in the level of the induced instability under either radiation condition, or for both strains of mice. Consequently, when

  13. Low-level radiation

    International Nuclear Information System (INIS)

    Myers, D.K.

    1982-05-01

    It is known that the normal incidence of cancer in human populations is increased by exposure to moderately high doses of ionizing radiation. At background radiation levels or at radiation levels which are 100 times greater, the potential health risks are considered to be directly proportional to the total accumulated dose of radiation. Some of the uncertainties associated with this assumption and with the accepted risk estimates have been critically reviewed in this document. The general scientific consensus at present suggests that the accepted risk estimates may exaggerate the actual risk of low levels of sparsely ionizing radiations (beta-, gamma- or X-rays) somewhat but are unlikely to overestimate the actual risks of densely ionizing radiations (fast neutrons, alpha-particles). At the maximum permissible levels of exposure for radiation workers in nuclear power stations, the potential health hazards in terms of life expectancy would be comparable to those encountered in transportation and public utilities or in the construction industry. At the average radiation exposures received by these workers in practice, the potential health hazards are similar to those associated with safe categories of industries. Uranium mining remains a relativly hazardous occupation. In terms of absolute numbers, the genetic hazards, which are less well established, are thought to be smaller than the carcinogenic hazards of radiation when only the first generation is considered but to be of the same order of magnitude as the carcinogenic hazards when the total number of induced genetic disorders is summed over all generations

  14. Genetics

    International Nuclear Information System (INIS)

    Hubitschek, H.E.

    1975-01-01

    Progress is reported on the following research projects: genetic effects of high LET radiations; genetic regulation, alteration, and repair; chromosome replication and the division cycle of Escherichia coli; effects of radioisotope decay in the DNA of microorganisms; initiation and termination of DNA replication in Bacillus subtilis; mutagenesis in mouse myeloma cells; lethal and mutagenic effects of near-uv radiation; effect of 8-methoxypsoralen on photodynamic lethality and mutagenicity in Escherichia coli; DNA repair of the lethal effects of far-uv; and near uv irradiation of bacterial cells

  15. Comparing genetic variants detected in the 1000 genomes project ...

    Indian Academy of Sciences (India)

    Single-nucleotide polymorphisms (SNPs) determined based on SNP arrays from the international HapMap consortium (HapMap) and the genetic variants detected in the 1000 genomes project (1KGP) can serve as two references for genomewide association studies (GWAS). We conducted comparative analyses to provide ...

  16. New horizontal global solar radiation estimation models for Turkey based on robust coplot supported genetic programming technique

    International Nuclear Information System (INIS)

    Demirhan, Haydar; Kayhan Atilgan, Yasemin

    2015-01-01

    Highlights: • Precise horizontal global solar radiation estimation models are proposed for Turkey. • Genetic programming technique is used to construct the models. • Robust coplot analysis is applied to reduce the impact of outlier observations. • Better estimation and prediction properties are observed for the models. - Abstract: Renewable energy sources have been attracting more and more attention of researchers due to the diminishing and harmful nature of fossil energy sources. Because of the importance of solar energy as a renewable energy source, an accurate determination of significant covariates and their relationships with the amount of global solar radiation reaching the Earth is a critical research problem. There are numerous meteorological and terrestrial covariates that can be used in the analysis of horizontal global solar radiation. Some of these covariates are highly correlated with each other. It is possible to find a large variety of linear or non-linear models to explain the amount of horizontal global solar radiation. However, models that explain the amount of global solar radiation with the smallest set of covariates should be obtained. In this study, use of the robust coplot technique to reduce the number of covariates before going forward with advanced modelling techniques is considered. After reducing the dimensionality of model space, yearly and monthly mean daily horizontal global solar radiation estimation models for Turkey are built by using the genetic programming technique. It is observed that application of robust coplot analysis is helpful for building precise models that explain the amount of global solar radiation with the minimum number of covariates without suffering from outlier observations and the multicollinearity problem. Consequently, over a dataset of Turkey, precise yearly and monthly mean daily global solar radiation estimation models are introduced using the model spaces obtained by robust coplot technique and

  17. Low-level radiation: a review of current estimates of hazards to human populations

    International Nuclear Information System (INIS)

    Myers, D.K.

    1977-12-01

    Mankind has always lived with low levels of ionizing radiation from natural sources. This ionizing radiation may induce cancers in irradiated persons and genetic defects in the descendents of irradiated persons. The internationally accepted estimates of risks suggest that the numbers of cancers and genetic defects induced in the general population by natural background radiation are not more than about 1% of the numbers of cancers and genetic defects normally present in the general population. The added risks to the general public due to any prospective nuclear power program are minute compared to those from background radiation. At the maximum permissible levels of radiation exposures for occupational workers, the predicted number of fatal cancers induced would lead to a reduction in average life-span from 73.0 years to about 72.7 years. Since occupational exposures are usually much less than maximum permissible levels, the risks are correspondingly reduced. These occupational risks are comparable to those in most other industries and occupations. Some areas of uncertainty in the accepted risk estimates are discussed in detail in this review. (author)

  18. Radiation hardness of diamond and silicon sensors compared

    CERN Document Server

    de Boer, Wim; Furgeri, Alexander; Mueller, Steffen; Sander, Christian; Berdermann, Eleni; Pomorski, Michal; Huhtinen, Mika

    2007-01-01

    The radiation hardness of silicon charged particle sensors is compared with single crystal and polycrystalline diamond sensors, both experimentally and theoretically. It is shown that for Si- and C-sensors, the NIEL hypothesis, which states that the signal loss is proportional to the Non-Ionizing Energy Loss, is a good approximation to the present data. At incident proton and neutron energies well above 0.1 GeV the radiation damage is dominated by the inelastic cross section, while at non-relativistic energies the elastic cross section prevails. The smaller inelastic nucleon-Carbon cross section and the light nuclear fragments imply that at high energies diamond is an order of magnitude more radiation hard than silicon, while at energies below 0.1 GeV the difference becomes significantly smaller.

  19. Comparative occupational radiation exposure between fixed and mobile imaging systems.

    Science.gov (United States)

    Kendrick, Daniel E; Miller, Claire P; Moorehead, Pamela A; Kim, Ann H; Baele, Henry R; Wong, Virginia L; Jordan, David W; Kashyap, Vikram S

    2016-01-01

    Endovascular intervention exposes surgical staff to scattered radiation, which varies according to procedure and imaging equipment. The purpose of this study was to determine differences in occupational exposure between procedures performed with fixed imaging (FI) in an endovascular suite compared with conventional mobile imaging (MI) in a standard operating room. A series of 116 endovascular cases were performed over a 4-month interval in a dedicated endovascular suite with FI and conventional operating room with MI. All cases were performed at a single institution and radiation dose was recorded using real-time dosimetry badges from Unfors RaySafe (Hopkinton, Mass). A dosimeter was mounted in each room to establish a radiation baseline. Staff dose was recorded using individual badges worn on the torso lead. Total mean air kerma (Kar; mGy, patient dose) and mean case dose (mSv, scattered radiation) were compared between rooms and across all staff positions for cases of varying complexity. Statistical analyses for all continuous variables were performed using t test and analysis of variance where appropriate. A total of 43 cases with MI and 73 cases with FI were performed by four vascular surgeons. Total mean Kar, and case dose were significantly higher with FI compared with MI. (mean ± standard error of the mean, 523 ± 49 mGy vs 98 ± 19 mGy; P < .00001; 0.77 ± 0.03 mSv vs 0.16 ± 0.08 mSv, P < .00001). Exposure for the primary surgeon and assistant was significantly higher with FI compared with MI. Mean exposure for all cases using either imaging modality, was significantly higher for the primary surgeon and assistant than for support staff (ie, nurse, radiology technologist) beyond 6 feet from the X-ray source, indicated according to one-way analysis of variance (MI: P < .00001; FI: P < .00001). Support staff exposure was negligible and did not differ between FI and MI. Room dose stratified according to case complexity (Kar) showed statistically significantly

  20. Assumed genetic effects of low level irradiation on man

    International Nuclear Information System (INIS)

    Dutrillaux, B.

    1976-01-01

    The significance of human genetic pathology is stated and a study is made of the assumed effect of low level ionizing radiations. The theoretical notions thus derived are compared to experimental data which are poor. A quick survey of the literature shows that is has not yet been possible to establish a direct relationship between an increase of exposure and any genetic effect on man. However, this must not lead to conclude on the innoxiousness of radiation but rather shows how such analyses are difficult in as much as the effect investigated is necessarily low [fr

  1. Radiation effects, nuclear energy and comparative risks

    International Nuclear Information System (INIS)

    Gopinath, D.V.

    2007-01-01

    Nuclear energy had a promising start as an unlimited, inexpensive and environmentally benign source of energy for electricity generation. However, over the decades its growth was severely retarded due to concerns about its possible detrimental effects on the well-being of mankind and the environment. Since such concerns are essentially due to the gigantic magnitude of radioactivity and ionizing radiations associated with nuclear energy, this article starts with a comprehensive account of effects of the ionizing radiation on living systems. Quantitative description of types of radiation exposure and their varied effects is given. The origin, type and magnitude of mutagenic effects of radiation are described. The concept of radiation risk factors, basis for their evaluation and their currently accepted values are presented. With this background, origin and magnitude of radioactivity and associated ionizing radiations in nuclear reactors are presented and the elaborate measures to contain them are described. It is recognized that notwithstanding all the measures taken in the nuclear industry, certain amount of radiation exposure, however small, is inevitable and the values, based on the experience world over, are presented. Estimated health risk due to such exposures is evaluated. For a comparative analysis, risks in other options of electricity generation such as hydel and fossil-fuelled plants are described. It is seen that on an overall basis, the nuclear option is no more risky than the other commonly employed options, and is in fact, significantly less. Lastly, since every option of electricity generation entails some risk, the case of 'no addition of electricity, and its impact on the society are considered. Based on the analysis of extensive data provided by UNDP on the human development parameters for different countries in the world, it is shown that at least for developing countries, any option of addition of electricity would be far more desirable than the

  2. Radiation exposure and radiation risk of the population

    International Nuclear Information System (INIS)

    Jacobi, W.; Paretzke, H.G.; Ehling, U.H.

    1981-02-01

    The major scientifically founded results concerning the assessment of the radiation exposure and the analysis and evaluation of the radiationhazards for the population, particularly in the range of low doses, are presented. As to the risk analysis special attention is paid to the rays with low ionization density (X-, γ-, β- and electronrays). Contents: 1) Detailed survey of the results and conclusions; 2) Data on the radiation load of the population; 3) Results to epidemiological questioning on the risk of cancer; 4) Genetical radiation hazards of the population. For quantification purposes of the risk of cancer by γ-radiation the observations with the a-bomb survivors in Japan are taken as a basis, as the available dosimetrical data have to be revised. Appendices: 1) German translation of the UNSCEAR-Report (1977); 2) BEIR-Report (1980); 3) Comments from the SSK on the comparability of the risks of natural-artificial radiation exposure; 4) Comments from the SSK on the importance of synergistical influences for the radiation protection (23.9.1977). (HP) [de

  3. Comparative genetics of hybrid incompatibility: sterility in two Solanum species crosses.

    Science.gov (United States)

    Moyle, Leonie C; Nakazato, Takuya

    2008-07-01

    The genetic basis of hybrid sterility can provide insight into the genetic and evolutionary origins of species barriers. We examine the genetics of hybrid incompatibility between two diploid plant species in the plant clade Solanum sect. Lycopersicon. Using a set of near-isogenic lines (NILs) representing the wild species Solanum pennellii (formerly Lycopersicon pennellii) in the genetic background of the cultivated tomato S. lycopersicum (formerly L. esculentum), we found that hybrid pollen and seed infertility are each based on a modest number of loci, male (pollen) and other (seed) incompatibility factors are roughly comparable in number, and seed-infertility QTL act additively or recessively. These findings are remarkably consistent with our previous analysis in a different species pair, S. lycopersicum x S. habrochaites. Data from both studies contrast strongly with data from Drosophila. Finally, QTL for pollen and seed sterility from the two Solanum studies were chromosomally colocalized, indicating a shared evolutionary history for these QTL, a nonrandom genomic distribution of loci causing sterility, and/or a proclivity of certain genes to be involved in hybrid sterility. We show that comparative mapping data can delimit the probable timing of evolution of detected QTL and discern which sterility loci likely evolved earliest among species.

  4. Genetic effects of radiation in atomic-bomb survivors and their children. Past, present and future

    International Nuclear Information System (INIS)

    Nakamura, Nori

    2006-01-01

    Genetic studies in the offspring of atomic bomb survivors have been conducted since 1948 at the Atomic Bomb Casualty Commission and its successor, the Radiation Effects Research Foundation, in Hiroshima and Nagasaki. Past studies include analysis of birth defects (untoward pregnancy outcome; namely, malformation, stillbirth, and perinatal death), chromosome aberrations, alterations of plasma and erythrocyte proteins as well as epidemiologic study on mortality (any cause) and cancer incidence (the latter study is still ongoing). There is, thus far, no indication of genetic effects in the offspring of survivors. Recently, the development of molecular biological techniques and human genome sequence databases made it possible to analyze DNA from parents and their offspring (trio-analysis). In addition, a clinical program is underway to establish the frequency of adult-onset multi-factorial diseases (diabetes mellitus, high blood pressure, and cardiovascular disease etc) in the offspring. The complementary kinds of data that will emerge from this three-pronged approach (clinical, epidemiologic, and molecular aspects) promise to shed light on health effects in the offspring of radiation-exposed people. (author)

  5. Genetic risks of ionizing radiation

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1990-01-01

    Quantitative genetic risk estimation is made using two methods: the direct method, and the doubling dose (DD) method. The doubling dose currently used is 1 Gy for low LET, low dose, low dose rate irradiation, and is based on mouse data. Tables present the 1988 UNSCEAR estimates of genetic risk using both methods. (L.L.) (Tab.)

  6. Evidence for selection in response to radiation exposure: Pinus sylvestris in the Chernobyl exclusion zone

    International Nuclear Information System (INIS)

    Kuchma, Oleksandra; Finkeldey, Reiner

    2011-01-01

    Changes of genetic structures due to viability selection are likely to occur in populations exposed to rapidly and extremely changing environmental conditions after catastrophic events. However, very little is known about the extent of selective responses and in particular the proportion of the genome involved in putatively adaptive reactions for non-model plants. We used amplified fragment length polymorphisms (AFLPs) in order to investigate genetic differences between pine (Pinus sylvestris) trees which were partially exposed to extreme environmental conditions. Genetic variation patterns of pines exposed to high radiation in the Chernobyl exclusion zone with or without phenotypic stress symptoms were compared to control trees with a similar origin. Six percent of the investigated loci (15 of 222 loci) were identified as candidates for selective responses. Moderate differentiation was observed between groups of trees showing either weak or strong phenotypic responses to high radiation levels. - Highlights: → Genetic variation patterns of pines exposed to high radiation were investigated. → Pines with or without phenotypic stress symptoms were compared to control trees. → AFLP markers were used to reveal evidences of selection processes. → 15 of 222 loci are identified as candidates for selective responses. → Moderate differentiation is observed between irradiated and control trees. - Genetic responses to the exposure of trees to radiation in the Chernobyl zone may involve adaptive changes at a comparatively large part of the genome.

  7. A study about the effects of gamma radiation and electron beam irradiation in the detection of genetically modified maize (Zea Mays)

    International Nuclear Information System (INIS)

    Crede, Ricardo Gandara

    2005-01-01

    Cell-220 and electron beam irradiation (Radiation Dynamics Inc. USA) were used (Atomic Energy of Canada, LTD), applying doses of 1, 25 and 50 kGy. After irradiating the samples, the detection results were compared with non-irradiated samples, showing that, when the PCR technique, was used, the irradiation does not affect the perception of the genetically modified maize. (author)

  8. How effects of chemicals might differ from those of radiations in giving rise to genetic ill-health in man

    International Nuclear Information System (INIS)

    Evans, H.J.

    1980-01-01

    Possible differences between the effects of the two groups of agents are considered. Two types of genetic damage are discussed. The first type involves mutational changes induced in germ cells or germ cell precursors which are then transmitted to the products of conception and to any resultant offspring and their descendants. The second kind is that damage sustained by the genome in somatic cells which is transmitted to daughter cells. Such somatic mutations are not heritable in the familiar sense, but they are transmitted to descendant cells within the body. It is concluded that a greater heterogeneity is expected in mutagenic response to chemical mutagens than to radiations in human populations, that the spectrum of mutations following chemical exposure may be quite different from that following radiation exposure, and that for many chemical agents, and in contrast to ionising radiations, one might expect a greater burden of genetic ill-health due to increased frequencies of mildly deleterious recessive and polygenic mutations. (Auth.)

  9. Genetic topics in radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Traut, H [Muenster Univ. (F.R. Germany). Inst. fuer Strahlenbiologie

    1976-01-01

    The effects of mutations induced by ionizing radiation on human health can be subdivided into decrease of general viability, malformations and embryonic death. Reasons are given for the recommendation why a man whose gonads had been exposed to radiation should refrain from procreation for a couple of months. An analysis of the frequency of chromosome aberrations induced in lymphocytes can provide an estimate of the dose received during an accidental exposure. Radiation induced chronic myeloid leukaemia is probably based on the induction of an aberration involving chromosome 22 in a bone marrow cell (deletion, translocation). The relationship between the frequency of radiation induced point mutations and the DNA content of the genome of the species studied so far is discussed.

  10. An investigation of the statistical power of neutrality tests based on comparative and population genetic data

    DEFF Research Database (Denmark)

    Zhai, Weiwei; Nielsen, Rasmus; Slatkin, Montgomery

    2009-01-01

    In this report, we investigate the statistical power of several tests of selective neutrality based on patterns of genetic diversity within and between species. The goal is to compare tests based solely on population genetic data with tests using comparative data or a combination of comparative...... and population genetic data. We show that in the presence of repeated selective sweeps on relatively neutral background, tests based on the d(N)/d(S) ratios in comparative data almost always have more power to detect selection than tests based on population genetic data, even if the overall level of divergence...... selection. The Hudson-Kreitman-Aguadé test is the most powerful test for detecting positive selection among the population genetic tests investigated, whereas McDonald-Kreitman test typically has more power to detect negative selection. We discuss our findings in the light of the discordant results obtained...

  11. A comparative study of LRRK2, PINK1 and genetically undefined familial Parkinson's disease.

    Science.gov (United States)

    Nishioka, Kenya; Kefi, Mounir; Jasinska-Myga, Barbara; Wider, Christian; Vilariño-Güell, Carles; Ross, Owen A; Heckman, Michael G; Middleton, Lefkos T; Ishihara-Paul, Lianna; Gibson, Rachel A; Amouri, Rim; Ben Yahmed, Samia; Ben Sassi, Samia; Zouari, Mourad; El Euch, Ghada; Farrer, Matthew J; Hentati, Faycal

    2010-04-01

    Genetic classification of Parkinson's disease (PD) subtypes may become the preferred diagnostic tool for neurologists. Herein we compare clinical features from a large cohort of patients with familial PD of unknown aetiology or attributable to distinct genetic forms. Comprehensive neurological examinations were performed in 231 familial PD patients from Tunisia. Analysis was previously performed to screen for mutations in leucine rich repeat kinase 2 (LRRK2), PTEN induced kinase 1 (PINK1) and parkin (PRKN). Clinical features were compared between patients with genetically undefined PD (n=107) and those with LRRK2 (n=73) and PINK1 (n=42) mutations using regression analyses adjusted for gender, age of onset and disease duration. PRKN cases (n=9) were too few for meaningful statistical analysis. In comparison with genetically undefined patients, LRRK2 mutation carriers had more severe motor symptoms (median Unified Parkinson's Disease Rating Scale scores approximately 1.6 times higher, pundefined patients. As expected, PINK1 patients had younger ages and ages at disease onset, and a longer disease duration compared with LRRK2 mutation carriers and genetically undefined patients. Clinical differences between LRRK2, PINK1 and genetically undefined familial PD appear more pronounced than previously appreciated, and may prove useful in clinical practice. As future therapies are targeted to specific protein abnormalities, identifying the genetic causes and associated clinical and pathological features will determine diagnosis, preventative medicine and drug intervention strategies.

  12. Radiation-induced mutations in mammals

    International Nuclear Information System (INIS)

    Ehling, U.H.

    1993-01-01

    The aims of the proposed project are to provide a better basis for extrapolation of animal data to man. Genetic endpoint, strain and species comparisons are made, which will provide critical experimental data regarding strategies in extrapolating laboratory animal data to man. Experiments were conducted to systematically compare the spontaneous and radiation-induced mutation rates for recessive specific-locus, dominant cataract and enzyme activity alleles in the mouse as well as a comparison of the mutation rate in the mouse and hamster for dominant cataract and enzyme activity alleles. The comparison of the radiation-dose response for recessive specific-locus and dominant cataract mutations are extended. Selected mutations are characterized at the genetic, biochemical and molecular levels. (R.P.) 5 refs., 3 tabs

  13. YouGenMap: a web platform for dynamic multi-comparative mapping and visualization of genetic maps

    Science.gov (United States)

    Keith Batesole; Kokulapalan Wimalanathan; Lin Liu; Fan Zhang; Craig S. Echt; Chun Liang

    2014-01-01

    Comparative genetic maps are used in examination of genome organization, detection of conserved gene order, and exploration of marker order variations. YouGenMap is an open-source web tool that offers dynamic comparative mapping capability of users' own genetic mapping between 2 or more map sets. Users' genetic map data and optional gene annotations are...

  14. Mutation frequencies in male mice and the estimation of genetic hazards of radiation in men

    International Nuclear Information System (INIS)

    Russell, W.L.; Kelly, E.M.

    1982-01-01

    Estimation of the genetic hazards of ionizing radiation in men is based largely on the frequency of transmitted specific-locus mutations induced in mouse spermatogonial stem cells at low radiation dose rates. The publication of new data on this subject has permitted a fresh review of all the information available. The data continue to show no discrepancy from the interpretation that, although mutation frequency decreases markedly as dose rate is decreased from 90 to 0.8 R/min (1 R = 2.6 x 10/sup -4/ coulombs/kg) there seems to be no further change below 0.8 R/min over the range from that dose rate to 0.0007 R/min. Simple mathematical models are used to compute: (a) a maximum likelihood estimate of the induced mutation frequency at the low dose rates, and (b) a maximum likelihood estimate of the ratio of this to the mutation frequency at high dose rates in the range of 72 to 90 R/min. In the application of these results to the estimation of genetic hazards of radiation in man, the former value can be used to calcualte a doubling dose - i.e., the dose of radiation that induces a mutation frequency equal to the spontaneous frequency. The doubling dose based on the low-dose-rate data compiled here is 110 R. The ratio of the mutation frequency at low dose rate to to that at high dose rate is useful when it becomes necessary to extrapolate from experimental determinations, or from human data, at high dose rates to the expected risk at low dose rates. The ratio derived from the present analysis is 0.33

  15. Genetic study of resistance to inhibitory effects of UV radiation in rice (Oryza sativa)

    International Nuclear Information System (INIS)

    Sato, T.; Kang, H.S.; Kumagai, T.

    1994-01-01

    Genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice (Oryza sativa L.) cultivars was carried out. Some experimental plants were grown in visible radiation supplemented with UV radiation containing a large amount of UV-B and a small amount of UV-C in a phytotron, while others were grown without UV radiation. The degree of resistance to UV radiation was estimated in terms of the degree of reduction caused by supplemental UV radiation in the fresh weight of the aboveground plant parts and the chlorophyll content per unit fresh weight. Fresh weight and chlorophyll content in F 2 plants generated by reciprocally crossing cv. Sasanishiki, a cultivar more resistant to UV radiation, and Norin 1, a cultivar less resistant to such radiation exhibited a normal frequency distribution. The heritabilities of these two properties in F 2 plants were low under conditions of non-supplemental UV radiation. Under elevated UV radiation, the F 2 population shifted to the lower range of fresh weight and chlorophyll content, and the means were close to those of Norin 1. The heritabilities of these two properties were the same in the reciprocal crosses, indicating that maternal inheritance was not involved. Inheritance of chlorophyll content per unit fresh weight was further determined in F 3 lines generated by self-fertilizing F 2 plants of Sasanishiki and Norin 1. The results showed that the F 3 population was segregated into three genotypes, namely, resistant homozygotes, segregated heterozygotes and sensitive homozygotes, with a ratio of 1:65:16. It was thus evident that the resistance to the inhibitory effect of elevated UV radiation in these rice plants was controlled by recessive polygenes. (author)

  16. Radiation mutagenesis from molecular and genetic points of view

    International Nuclear Information System (INIS)

    Chen, D.J.C.; Park, M.S.; Okinaka, R.T.; Jaberaboansari, A.

    1993-01-01

    An important biological effect of ionizing radiation on living organisms is mutation induction. Mutation is also a primary event in the etiology of cancer. The chain events, from induction of DNA damage by ionizing radiation to processing of these damages by the cellular repair/replication machinery, that lead to mutation are not well understood. The development of quantitative methods for measuring mutation-induction, such as the HPRT system, in cultured mammalian cells has provided an estimate of the mutagenic effects of x- and γ-rays as wen as of high LET radiation in both rodent and human cells. A major conclusion from these mutagenesis data is that high LET radiation induces mutations more efficiently than g-rays. Molecular analysis of mutations induced by sparsely ionizing radiation have detected major structural alterations at the gene level. Our molecular results based on analysis of human HPRT deficient mutants induced by γ-rays, α-particles and high energy charged particles indicate that higher LET radiation induce more total and large deletion mutations than γ-rays. Utilizing molecular techniques including polymerase chain reaction (PCR), Single-strand conformation polymorphism (SSCP), denaturing gradient gel electrophoresis (DGGE) and Direct DNA sequencing, mutational spectra induced by ionizing radiation have been compared in different cell systems. Attempts have also been made to determine the mutagenic potential and the nature of mutation induced by low dose rate γ-rays. Defective repair, in the form of either a diminished capability for repair or inaccurate repair, can lead to increased risk of heritable mutations from radiation exposure. Therefore, the effects of DNA repair deficiency on the mutation induction in mammalian cells is reviewed

  17. Oncogenes and radiation resistance - a review

    International Nuclear Information System (INIS)

    Dritschilo, A.

    1992-01-01

    Oncogenes exert their effects on the genetic programs of cells by regulating signal transduction pathways, resulting in multi-factorial genetic responses. By such actions, the genetic elements responsible for the cellular responses to ionizing radiation may be affected. Reports implicating the association of oncogene expression with modulation of the radiation response include the ras, raf, and myc genes. Experiments overexpressing H-ras and c-raf-1 using genetically engineered constructs result in enhanced post-radiation cellular survival. Conversely, inhibition of raf gene expression has resulted in relative radiation sensitization and delay of human squamous cell carcinoma tumor growth in nude mice. There appears to be a potential strategy for therapeutic intervention. The identification of genes that confer survival advantage following radiation exposure, and understanding their mechanisms of action, may permit a genetically based intervention for radiation sensitization. One such approach employs oligo-deoxynucleotides complementary to oncogene-encoded in RNA's (antisense DNA). (author)

  18. Radiolethal and genetic vulnerabilities of germ cells in the female mammal: Effects of tritium and other radiations compared

    International Nuclear Information System (INIS)

    Straume, T.; Kwan, T.C.; Goldstein, L.S.; Dobson, R.L.

    1989-01-01

    Our focus is on the nature of the lethality target in very sensitive cells. In the mouse, several types of radiations have now been used, including 3 H-Tdr incorporated into oocyte DNA, gamma rays delivered at various dose rates, 250 kVp x rays, neutrons of various energies, and three kinds of accelerated heavy ions (Si 14+ , Ar 18+ , Fe 26+ ). We have shown that the lethality target in mouse immature oocytes is non-nuclear; it is equal in cross-sectional area to the entire oocyte and is separated from the nucleus by about 4 μm. A substantial body of data now points to the plasma membrane as the lethality target in these particular cells. We have quantified both chromosome aberrations and dominant lethal mutations in oocytes from females exposed 8 to 12 weeks earlier. Results from these and other studies show that: (1) for immature oocyte killing in mice, chronically administered 3 HOH is of near maximum biological effectiveness, similar to the most effective neutrons and heavy ions (likely true also for female germ-cell killing in some prenatal primates), (2) tritium incorporated into DNA as 3 H-Tdr is about 100 times less effective in mouse immature oocyte killing than is tritium administered as 3 HOH, and (3) for mutagenicity in the mouse, immature oocytes appear to have approximately the same sensitivity as mature oocytes and show dose and LET responses similar to those obtained from genetic studies of other cells. The possible implications of these findings for women exposed to tritium are considered

  19. Facilitated pronociceptive pain mechanisms in radiating back pain compared with localized back pain

    DEFF Research Database (Denmark)

    Vaegter, Henrik Bjarke; Palsson, Thorvaldur Skuli; Graven-Nielsen, Thomas

    2017-01-01

    Facilitated pain mechanisms and impaired pain inhibition are often found in chronic pain patients. This study compared clinical pain profiles, pain sensitivity, as well as pro-nociceptive and anti-nociceptive mechanisms in patients with localized low back pain (n=18), localized neck pain (n=17......), low back and radiating leg pain (n=18), or neck and radiating arm pain (n=17). It was hypothesized that patients with radiating pain had facilitated pain mechanisms and impaired pain inhibition compared with localized pain patients. Cuff algometry was performed on the non-painful lower leg to assess...... threshold (HPT) at the non-painful hand were also assessed. Clinical pain intensity, psychological distress, and disability were assessed with questionnaires. TSP was increased in patients with radiating back pain compared with localized back pain (Ppain or localized low...

  20. Influence of genetic immune disorders and anemia in radiation leukemogenesis

    International Nuclear Information System (INIS)

    Wilson, F.D.; Cain, G.; Graham, R.; Fox, L.; Klein, A.K.; Stitzel, K.; Dyck, J.; Shimizu, J.

    1980-01-01

    Genetic and disease related conditions (anemia and immunoblastic lymphadenopathy) were studied in mice to determine if these variables influenced cellular damage from continuous low-level irradiation. Strain differences were observed in pre-irradiation profiles for cardiac blood and lymphohematopoietic progenitor cell parameters. Major differences with respect to genetic and disease variables were seen in response to continuous irradiation. Presence of a stem cell defect in the W/W/sup ν/ strain with resulting pre-irradiation anemia had profound effects on the ability of these mice to maintain erythrogenesis during continuous irradiation. Likewise, granulocyte-monocyte precursors were markedly depressed in the WW/sup ν/ strain during the irradiation period. The immunologically abnormal stran, BXSB, which suffers from a lymphoproliferative processes, showed marked sensitivity in WBC to the effects of continuous irradiation. WBC values precipitously dropped during the first week of exposure then rapidly compensated to values 264% of unirradiated controls. The hyperplastic B cells in this strain also show marked radiation sensitivity and ability to repair to above normal levels. Lymphohematopoietic malignancy has been recognized in two individuals to date - both cases were in diseased irradiated mice: (1) disseminated lymphosarcoma in one W/W/sup ν/ mouse; and (2) acute lymphocytic leukemia in one BXSB mouse

  1. The genetic architecture of novel trophic specialists: larger effect sizes are associated with exceptional oral jaw diversification in a pupfish adaptive radiation.

    Science.gov (United States)

    Martin, Christopher H; Erickson, Priscilla A; Miller, Craig T

    2017-01-01

    The genetic architecture of adaptation is fundamental to understanding the mechanisms and constraints governing diversification. However, most case studies focus on loss of complex traits or parallel speciation in similar environments. It is still unclear how the genetic architecture of these local adaptive processes compares to the architecture of evolutionary transitions contributing to morphological and ecological novelty. Here, we identify quantitative trait loci (QTL) between two trophic specialists in an excellent case study for examining the origins of ecological novelty: a sympatric radiation of pupfishes endemic to San Salvador Island, Bahamas, containing a large-jawed scale-eater and a short-jawed molluscivore with a skeletal nasal protrusion. These specialized niches and trophic traits are unique among over 2000 related species. Measurements of the fitness landscape on San Salvador demonstrate multiple fitness peaks and a larger fitness valley isolating the scale-eater from the putative ancestral intermediate phenotype of the generalist, suggesting that more large-effect QTL should contribute to its unique phenotype. We evaluated this prediction using an F2 intercross between these specialists. We present the first linkage map for pupfishes and detect significant QTL for sex and eight skeletal traits. Large-effect QTL contributed more to enlarged scale-eater jaws than the molluscivore nasal protrusion, consistent with predictions from the adaptive landscape. The microevolutionary genetic architecture of large-effect QTL for oral jaws parallels the exceptional diversification rates of oral jaws within the San Salvador radiation observed over macroevolutionary timescales and may have facilitated exceptional trophic novelty in this system. © 2016 John Wiley & Sons Ltd.

  2. Comparative proteomic analysis of rice after seed ground simulated radiation and spaceflight explains the radiation effects of space environment

    Science.gov (United States)

    Wang, Wei; Shi, Jinming; Liang, Shujian; Lei, Huang; Shenyi, Zhang; Sun, Yeqing

    In previous work, we compared the proteomic profiles of rice plants growing after seed space-flights with ground controls by two-dimensional difference gel electrophoresis (2-D DIGE) and found that the protein expression profiles were changed after seed space environment exposures. Spaceflight represents a complex environmental condition in which several interacting factors such as cosmic radiation, microgravity and space magnetic fields are involved. Rice seed is in the process of dormant of plant development, showing high resistance against stresses, so the highly ionizing radiation (HZE) in space is considered as main factor causing biological effects to seeds. To further investigate the radiation effects of space environment, we performed on-ground simulated HZE particle radiation and compared between the proteomes of seed irra-diated plants and seed spaceflight (20th recoverable satellite) plants from the same rice variety. Space ionization shows low-dose but high energy particle effects, for searching the particle effects, ground radiations with the same low-dose (2mGy) but different liner energy transfer (LET) values (13.3KeV/µm-C, 30KeV/µm-C, 31KeV/µm-Ne, 62.2KeV/µm-C, 500Kev/µm-Fe) were performed; using 2-D DIGE coupled with clustering and principle component analysis (PCA) for data process and comparison, we found that the holistic protein expression patterns of plants irradiated by LET-62.2KeV/µm carbon particles were most similar to spaceflight. In addition, although space environment presents a low-dose radiation (0.177 mGy/day on the satellite), the equivalent simulated radiation dose effects should still be evaluated: radiations of LET-62.2KeV/µm carbon particles with different cumulative doses (2mGy, 20mGy, 200mGy, 2000mGy) were further carried out and resulted that the 2mGy radiation still shared most similar proteomic profiles with spaceflight, confirming the low-dose effects of space radiation. Therefore, in the protein expression level

  3. Induction of Genetic Variation with Recurrent Gamma Radiation in Centipedegrass (Eremochloa ophiuroides)

    International Nuclear Information System (INIS)

    Lim Keun- Bal; Rim Yong-Woo

    1998-01-01

    Centipedegrass (Eremochloa ophiuroides) is a popular lawn grass in the southeastern USA. It has a naturally light green color and grows well on a wide range of soil types. Studies show limited morphological variation present in centipedegrass germplasm. To obtain the high morphological variation, plants were established from the irradiated seed at 10 Kr, allowed to interpollinate and harvested bulk seed, and then irradiated again for the next cycles. Morphological characteristics were measured in the 5 genetic varition lines (TC201:cv. Common and non irradiated, TC202:4th cycles, TC241:6th cycles, TC306:8th cycles, and TC318:5th cycles) induced by recurrent gamma radiation. The ranges of variation of recurrently radiated centipedegrass lines TC202, TC241, and TC306 except TC318(TifBlair) for the stolons per plant, total stolon length per plant, longest stolon length, leaf length and width at top-most exposed internode were wider than those of non-irradiated line (TC201). Recurrent gamma radiation was very effective to enlarge the ranges of variation of morphological characteristics in reproductive organ like stolons of centipedegrass. The effect of quantity of gamma ray irradiation cycles on the means and ranges of variation in the morphological characteristics of centipedegrass was not regularly tended

  4. The use of recombinant DNA techniques to study radiation-induced damage, repair and genetic change in mammalian cells

    International Nuclear Information System (INIS)

    Thacker, J.

    1986-01-01

    A brief introduction is given to appropriate elements of recombinant DNA techniques and applications to problems in radiobiology are reviewed with illustrative detail. Examples are included of studies with both 254 nm ultraviolet light and ionizing radiation and the review progresses from the molecular analysis of DNA damage in vitro through to the nature of consequent cellular responses. The review is dealt with under the following headings: Molecular distribution of DNA damage, The use of DNA-mediated gene transfer to assess damage and repair, The DNA double strand break: use of restriction endonucleases to model radiation damage, Identification and cloning of DNA repair genes, Analysis of radiation-induced genetic change. (UK)

  5. Toward genetics-based virus taxonomy: comparative analysis of a genetics-based classification and the taxonomy of picornaviruses.

    Science.gov (United States)

    Lauber, Chris; Gorbalenya, Alexander E

    2012-04-01

    Virus taxonomy has received little attention from the research community despite its broad relevance. In an accompanying paper (C. Lauber and A. E. Gorbalenya, J. Virol. 86:3890-3904, 2012), we have introduced a quantitative approach to hierarchically classify viruses of a family using pairwise evolutionary distances (PEDs) as a measure of genetic divergence. When applied to the six most conserved proteins of the Picornaviridae, it clustered 1,234 genome sequences in groups at three hierarchical levels (to which we refer as the "GENETIC classification"). In this study, we compare the GENETIC classification with the expert-based picornavirus taxonomy and outline differences in the underlying frameworks regarding the relation of virus groups and genetic diversity that represent, respectively, the structure and content of a classification. To facilitate the analysis, we introduce two novel diagrams. The first connects the genetic diversity of taxa to both the PED distribution and the phylogeny of picornaviruses. The second depicts a classification and the accommodated genetic diversity in a standardized manner. Generally, we found striking agreement between the two classifications on species and genus taxa. A few disagreements concern the species Human rhinovirus A and Human rhinovirus C and the genus Aphthovirus, which were split in the GENETIC classification. Furthermore, we propose a new supergenus level and universal, level-specific PED thresholds, not reached yet by many taxa. Since the species threshold is approached mostly by taxa with large sampling sizes and those infecting multiple hosts, it may represent an upper limit on divergence, beyond which homologous recombination in the six most conserved genes between two picornaviruses might not give viable progeny.

  6. Genetic Algorithm with Maximum-Minimum Crossover (GA-MMC) Applied in Optimization of Radiation Pattern Control of Phased-Array Radars for Rocket Tracking Systems

    Science.gov (United States)

    Silva, Leonardo W. T.; Barros, Vitor F.; Silva, Sandro G.

    2014-01-01

    In launching operations, Rocket Tracking Systems (RTS) process the trajectory data obtained by radar sensors. In order to improve functionality and maintenance, radars can be upgraded by replacing antennas with parabolic reflectors (PRs) with phased arrays (PAs). These arrays enable the electronic control of the radiation pattern by adjusting the signal supplied to each radiating element. However, in projects of phased array radars (PARs), the modeling of the problem is subject to various combinations of excitation signals producing a complex optimization problem. In this case, it is possible to calculate the problem solutions with optimization methods such as genetic algorithms (GAs). For this, the Genetic Algorithm with Maximum-Minimum Crossover (GA-MMC) method was developed to control the radiation pattern of PAs. The GA-MMC uses a reconfigurable algorithm with multiple objectives, differentiated coding and a new crossover genetic operator. This operator has a different approach from the conventional one, because it performs the crossover of the fittest individuals with the least fit individuals in order to enhance the genetic diversity. Thus, GA-MMC was successful in more than 90% of the tests for each application, increased the fitness of the final population by more than 20% and reduced the premature convergence. PMID:25196013

  7. Comparative study of genetic influence on the susceptibility of exotic ...

    African Journals Online (AJOL)

    This study investigated comparatively the genetic influence on the susceptibility of exotic cockerels, pullets and broilers to natural infection with infectious bursal disease (IBD) virus in a flock of 150 seven-week-old exotic breed of chickens comprising of 50 Black Harco cockerels, 50 Black Harco pullets and 50 White ...

  8. Introduction to radiation biology

    International Nuclear Information System (INIS)

    Uma Devi, P.; Satish Rao, B.S.; Nagarathnam, A.

    2000-01-01

    This book is arranged in a logical sequence, starting from radiation physics and radiation chemistry, followed by molecular, subcellular and cellular effects and going on to the level of organism. Topics covered include applied radiobiology like modifiers of radiosensitivity, predictive assay, health physics, human genetics and radiopharmaceuticals. The topics covered are : 1. Radiation Physics, 2. Detection and Measurement of Radiation, 3. Radiation Chemistry, 4. DNA Damage and Repair, 5. Chromosomal Aberrations and Gene Mutations, 6. Cellular Radiobiology 7. Acute Radiation Effects, 8. Delayed Effects of Radiation, 9. Biological Basis of Radiotherapy, 10. Chemical Modifiers of Radiosensitivity, 11. Hyperthermia, 12. High LET Radiations in Cancer, Therapy, 13. Predictive Assays, 14. Radiation Effects on Embryos, 15. Human Radiation Genetics, 16. Radiolabelled Compounds in Biology and Medicine and 17. Radiological Health

  9. Studies of the repair of radiation-induced genetic damage in drosophila. Annual progress report

    International Nuclear Information System (INIS)

    Genetic characteristics of mutagen-sensitive mutants linked to the X chromosome were studied. These mutants increase loss and nondisjunction of chromosomes in female meiosis and are sensitive to radiation and mutagens. A study of chemical characteristics of the mutant suggested the existence of two separate forms of postreplication repair. One pathway is not caffeine sensitive and does not require recombination related functions; the second pathway appears to be caffeine sensitive and probably shares functions involved in meiotic recombination

  10. A comparative analysis of genetic differentiation across six shared willow host species in leaf- and bud-galling sawflies.

    Directory of Open Access Journals (Sweden)

    Sanna A Leppänen

    Full Text Available Genetic divergence and speciation in plant-feeding insects could be driven by contrasting selection pressures imposed by different plant species and taxa. While numerous examples of host-associated differentiation (HAD have been found, the overall importance of HAD in insect diversification remains unclear, as few studies have investigated its frequency in relation to all speciation events. One promising way to infer the prevalence and repeatability of HAD is to estimate genetic differentiation in multiple insect taxa that use the same set of hosts. To this end, we measured and compared variation in mitochondrial COI and nuclear ITS2 sequences in population samples of leaf-galling Pontania and bud-galling Euura sawflies (Hymenoptera: Tenthredinidae collected from six Salix species in two replicate locations in northern Fennoscandia. We found evidence of frequent HAD in both species complexes, as individuals from the same willow species tended to cluster together on both mitochondrial and nuclear phylogenetic trees. Although few fixed differences among the putative species were found, hierarchical AMOVAs showed that most of the genetic variation in the samples was explained by host species rather than by sampling location. Nevertheless, the levels of HAD measured across specific pairs of host species were not correlated in the two focal galler groups. Hence, our results support the hypothesis of HAD as a central force in herbivore speciation, but also indicate that evolutionary trajectories are only weakly repeatable even in temporally overlapping radiations of related insect taxa.

  11. Hazards of radiation exposure

    International Nuclear Information System (INIS)

    Solomon, S.B.

    1982-01-01

    Radiation induced carcinogenesis and mutagenesis form the main risks to health from exposure to low levels of radiation. There is scant data on somatic and genetic risks at environmental and occupational levels of radiation exposure. The available data on radiation induced carcinogenesis and mutagenesis are for high doses and high dose rates of radiation. Risk assessments for low level radiation are obtained using these data, assuming a linear dose-response relationship. During uranium mining the chief source of radiation hazard is inhalation of radon daughters. The correlation between radon daughter exposure and the increased incidence of lung cancer has been well documented. For radiation exposures at and below occupational limits, the associated risk of radiation induced cancers and genetic abnormalities is small and should not lead to a detectable increase over naturally occurring rates

  12. The effect of ultrasound and its combination with radiation on the genetic material of Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Silhankova, L.; Malkova-Kadlecova, Z.; Studlarova, Z.

    1978-01-01

    Ultrasonic radiation at 20 kHz with intensity 35 W/cm 2 and amplitude 15 to 25 μm applied to a diploid strain of Saccharomyces cerevisiae was found to act as a weak mutagen with maximum efficiency at the 20% survival of the cells. Under these conditions, the frequency of reversion of the suppressible allele ilv1-92 increased ten times, the frequency of mitotic gene conversion four times. Doses leading to survivals lower than 20% led to a slight increase in the frequency of cytoplasmic respiration-deficient mutants. Submutagenic doses applied immediately after γ or UV irradiation did not substantially increase the effect of these physical agents on the genetic material of the yeast strain investigated. Application of ultrasound prior to UV radiation did not considerably influence the effect of the UV radiation either. (author)

  13. 51. Brazilian congress on genetics. From biostatistics to bioinformatics. Genomic era. Abstracts

    International Nuclear Information System (INIS)

    2005-01-01

    Use of radioisotopes and ionizing radiations in genetics is presented. Several aspects related to men, animals, plants and microorganisms are reported highlighting biological radiation effects, evolution, mutagenesis and genetic engineering. Genetic mapping, polymerase chain reaction, gene mutations, genetic diversity, DNA hybridization, DNA sequencing, plant cultivation and plant grow are studied as well. Goiania radiation accident is mentioned and biological radiation effects of Cesium 137 are evaluated by biological indicators and radiation environmental monitoring

  14. Methods to estimate the genetic risk

    International Nuclear Information System (INIS)

    Ehling, U.H.

    1989-01-01

    The estimation of the radiation-induced genetic risk to human populations is based on the extrapolation of results from animal experiments. Radiation-induced mutations are stochastic events. The probability of the event depends on the dose; the degree of the damage dose not. There are two main approaches in making genetic risk estimates. One of these, termed the direct method, expresses risk in terms of expected frequencies of genetic changes induced per unit dose. The other, referred to as the doubling dose method or the indirect method, expresses risk in relation to the observed incidence of genetic disorders now present in man. The advantage of the indirect method is that not only can Mendelian mutations be quantified, but also other types of genetic disorders. The disadvantages of the method are the uncertainties in determining the current incidence of genetic disorders in human and, in addition, the estimasion of the genetic component of congenital anomalies, anomalies expressed later and constitutional and degenerative diseases. Using the direct method we estimated that 20-50 dominant radiation-induced mutations would be expected in 19 000 offspring born to parents exposed in Hiroshima and Nagasaki, but only a small proportion of these mutants would have been detected with the techniques used for the population study. These methods were used to predict the genetic damage from the fallout of the reactor accident at Chernobyl in the vicinity of Southern Germany. The lack of knowledge for the interaction of chemicals with ionizing radiation and the discrepancy between the high safety standards for radiation protection and the low level of knowledge for the toxicological evaluation of chemical mutagens will be emphasized. (author)

  15. Genetic effects from internally deposited radionuclides

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    It was learned in the late 1920's that ionizing radiation could produce genetic effects such as gene mutations and chromosome aberrations. However, at least until 1945, the focus on interest in radiation protection was primarily on somatic effects manifested in the individual exposed. Studies of the genetic effects of radiation using drosophila, however, refocused attention on effects transmitted to the exposed individuals offspring and concern over fallout in the 1950's resulted in efforts to estimate the genetic effects from exposure of human populations to internally deposited radionuclides. No human populations have been identified with burdens of internally deposited radioactive materials which have been shown to produce evidence of transmissible genetic damage. As a result, the research approach has been one in which macromolecular, cellular, and whole animal genetic studies have been combined to estimate genetic effects on humans following the deposition of radioactive materials in the body. The purpose of this report is to update the information available from animal and cellular experiments that relates genetic effects to deposited activity and dose from internally deposited radioactive materials

  16. 49. Brazilian congress on genetics. DNA double helix. Abstracts

    International Nuclear Information System (INIS)

    2003-01-01

    Use of radioisotopes and ionizing radiations in genetics is presented. Several aspects related to men, animals, plants and microorganisms are reported highlighting biological radiation effects, evolution, mutagenesis and genetic engineering. Genetic mapping, gene mutations, genetic diversity, DNA hybridization, DNA sequencing, plant cultivation and plant grow are studied as well

  17. Photosensitized inactivation of DNA by monochromatic 334-nm radiation in the presence of 2-thiouracil: genetic activity and backbone breaks

    International Nuclear Information System (INIS)

    Peak, M.J.; Ito, A.; Peak, J.G.; Foote, C.S.

    1988-01-01

    Monochromatic 334-nm radiation delivered under aerobic conditions inactivates the genetic activity (ability to transform auxotrophic recipient cells to nutritional prototrophy) of isolated transforming Bacillus subtilis DNA. The presence of superoxide dismutase (SOD), catalase, and mannitol reduces the 334-nm inactivation. The rate of inactivation of the genetic activity by 334-nm radiation is enhanced fivefold by the sensitizer 2-thiouracil (s 2 Ura). This enhancement is substantially reversed when the irradiations are performed in the presence of mannitol, and, to a lesser extent, SOD. Catalase slightly reduces the s 2 Ura enhancement of 334-nm inactivation of transforming activity. Backbone breaks induced in the same DNA by aerobic 334-nm radiation were also enhanced markedly by the presence of s 2 Ura; this enhancement was reversed by the presence of mannitol and, to a lesser extent, SOD during irradiation. Catalase had no effect upon s 2 Ura-enhanced, 334-nm-induced SSBs. Whereas DNA breakage may be responsible for a portion of the inactivation of the DNA by the photosensitized reaction between s 2 Ura and 334-nm radiation, it is not the only inactivating lesion, because the yield of SSBs per lethal hit per unit length of DNA is not constant for all the irradiation conditions studied. (author)

  18. Genetic susceptibility to mammary carcinogenesis in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, Kenji; Nitta, Yumiko [Hiroshima Univ. (Japan). Research Inst. for Radiation Biology and Medicine

    1999-06-01

    The Copenhagen (COP) rat strain has previously been shown to be genetically resistant to chemical induction of breast cancer, while Wistar/Furth (WF) and Fischer 344 (F344) animals are relatively susceptible. We have compared the carcinogenic response of these three strains of rats to N-methyl-N-nitrosourea (MNU) with that to {sup 60}Co gamma rays. High incidences of mammary carcinomas were induced by MNU in the F344 and WF rats (100%), whereas the COP strain proved resistant (11.8%). In contrast, radiation-induced mammary carcinomas in COP rats developed in a similar incidence (37.0%) to those in the F344 (22.6%) and WF (26.9%) strains. The low incidence of papillary carcinomas in MNU-treated COP rats appeared to be directly related to the COP genetic resistance controlled by the Mcs genes. Ionizing radiation did, however, induce papillary carcinomas in all the three strains of rats. These carcinomas were more differentiated than MNU-induced cancers with regard to the two mammary differentiation markers, rat milk fat globule membrane (R-MFGM) and {alpha}-smooth muscle actin ({alpha}-SMA). Furthermore, ionizing radiation but not MNU induced mammary adenomas in all three strains, especially in COP rats. Such adenomas had differentiation marker profiles similar to these of carcinomas induced by {sup 60}Co gamma rays. When transplanted into syngenic hosts, growth of adenomas was 17 {beta}-estradiol (E{sub 2})-dependent and they progressed to carcinomas. Furthermore, one microcarcinoma was observed to develop from adenoma tissue in a radiation-exposed COP rat. The findings suggest that radiation and chemical carcinogens are likely to induce mammary cancers through different pathways or from different cell populations. The induction of relatively high incidences of mammary carcinomas and adenomas by radiation in COP rats may correlate with the genetically modulated and highly differentiated physiological status of their mammary glands. (author)

  19. Radiation risks for patients having X rays

    International Nuclear Information System (INIS)

    Hale, J.; Thomas, J.W.

    1985-01-01

    In addition to radiation from naturally occurring radioactive materials and cosmic rays, individuals in developed countries receive radiation doses to bone marrow and gonads from the medical diagnostic use of X rays. A brief discussion of radiation epidemiology shows that deleterious effects are low even when doses are high. The concept of acceptable risk is introduced to help evaluate the small, but still existent, risks of radiation dose. Examples of bone marrow and gonadal doses for representative X-ray examinations are presented along with the current best estimates, per unit of X-ray dose, of the induction of leukemia or of genetic harm. The risk to the patient from an examination can then be compared with the normal risk of mortality from leukemia or of the occurrence of genetic defects. The risk increase is found to be very low. The risks to unborn children from radiographic examinations are also discussed. The benefit to the patient from information obtained from the examination must be balanced against the small risks

  20. Unique proteomic signature for radiation sensitive patients; a comparative study between normo-sensitive and radiation sensitive breast cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Skiöld, Sara [Center for Radiation Protection Research, Department of Molecular Biosciences, The Wernner-Gren Institute, Stockholm University, Stockholm (Sweden); Azimzadeh, Omid [Institute of Radiation Biology, German Research Center for Environmental Health, Helmholtz Zentrum München (Germany); Merl-Pham, Juliane [Research Unit Protein Science, German Research Center for Environmental Health, Helmholtz Zentrum München, Neuherberg (Germany); Naslund, Ingemar; Wersall, Peter; Lidbrink, Elisabet [Division of Radiotherapy, Radiumhemmet, Karolinska University Hospital, Stockholm (Sweden); Tapio, Soile [Institute of Radiation Biology, German Research Center for Environmental Health, Helmholtz Zentrum München (Germany); Harms-Ringdahl, Mats [Center for Radiation Protection Research, Department of Molecular Biosciences, The Wernner-Gren Institute, Stockholm University, Stockholm (Sweden); Haghdoost, Siamak, E-mail: Siamak.Haghdoost@su.se [Center for Radiation Protection Research, Department of Molecular Biosciences, The Wernner-Gren Institute, Stockholm University, Stockholm (Sweden)

    2015-06-15

    Highlights: • The unique protein expression profiles were found that separate radiosensitive from normal sensitive breast cancer patients. • The oxidative stress response, coagulation properties and acute phase response suggested to be the hallmarks of radiation sensitivity. - Abstract: Radiation therapy is a cornerstone of modern cancer treatment. Understanding the mechanisms behind normal tissue sensitivity is essential in order to minimize adverse side effects and yet to prevent local cancer reoccurrence. The aim of this study was to identify biomarkers of radiation sensitivity to enable personalized cancer treatment. To investigate the mechanisms behind radiation sensitivity a pilot study was made where eight radiation-sensitive and nine normo-sensitive patients were selected from a cohort of 2914 breast cancer patients, based on acute tissue reactions after radiation therapy. Whole blood was sampled and irradiated in vitro with 0, 1, or 150 mGy followed by 3 h incubation at 37 °C. The leukocytes of the two groups were isolated, pooled and protein expression profiles were investigated using isotope-coded protein labeling method (ICPL). First, leukocytes from the in vitro irradiated whole blood from normo-sensitive and extremely sensitive patients were compared to the non-irradiated controls. To validate this first study a second ICPL analysis comparing only the non-irradiated samples was conducted. Both approaches showed unique proteomic signatures separating the two groups at the basal level and after doses of 1 and 150 mGy. Pathway analyses of both proteomic approaches suggest that oxidative stress response, coagulation properties and acute phase response are hallmarks of radiation sensitivity supporting our previous study on oxidative stress response. This investigation provides unique characteristics of radiation sensitivity essential for individualized radiation therapy.

  1. Unique proteomic signature for radiation sensitive patients; a comparative study between normo-sensitive and radiation sensitive breast cancer patients

    International Nuclear Information System (INIS)

    Skiöld, Sara; Azimzadeh, Omid; Merl-Pham, Juliane; Naslund, Ingemar; Wersall, Peter; Lidbrink, Elisabet; Tapio, Soile; Harms-Ringdahl, Mats; Haghdoost, Siamak

    2015-01-01

    Highlights: • The unique protein expression profiles were found that separate radiosensitive from normal sensitive breast cancer patients. • The oxidative stress response, coagulation properties and acute phase response suggested to be the hallmarks of radiation sensitivity. - Abstract: Radiation therapy is a cornerstone of modern cancer treatment. Understanding the mechanisms behind normal tissue sensitivity is essential in order to minimize adverse side effects and yet to prevent local cancer reoccurrence. The aim of this study was to identify biomarkers of radiation sensitivity to enable personalized cancer treatment. To investigate the mechanisms behind radiation sensitivity a pilot study was made where eight radiation-sensitive and nine normo-sensitive patients were selected from a cohort of 2914 breast cancer patients, based on acute tissue reactions after radiation therapy. Whole blood was sampled and irradiated in vitro with 0, 1, or 150 mGy followed by 3 h incubation at 37 °C. The leukocytes of the two groups were isolated, pooled and protein expression profiles were investigated using isotope-coded protein labeling method (ICPL). First, leukocytes from the in vitro irradiated whole blood from normo-sensitive and extremely sensitive patients were compared to the non-irradiated controls. To validate this first study a second ICPL analysis comparing only the non-irradiated samples was conducted. Both approaches showed unique proteomic signatures separating the two groups at the basal level and after doses of 1 and 150 mGy. Pathway analyses of both proteomic approaches suggest that oxidative stress response, coagulation properties and acute phase response are hallmarks of radiation sensitivity supporting our previous study on oxidative stress response. This investigation provides unique characteristics of radiation sensitivity essential for individualized radiation therapy

  2. Radiation induced late delayed alterations in mice brain after whole body and cranial radiation: a comparative DTI analysis

    International Nuclear Information System (INIS)

    Watve, Apurva; Gupta, Mamta; Trivedi, Richa; Khushu, Subash; Rana, Poonam

    2016-01-01

    Moderate dose of radiation exposure occurs during radiation accidents or radiation therapy induces pathophysiological alterations in CNS that may persist for longer duration. Studies suggest that late delayed injury is irreversible leading to metabolic and cognitive impairment. Our earlier studies have illustrated the varied response of brain at acute and early delayed phase on exposure to cranial and whole body radiation. Hence in continuation with our previous studies, present study focuses on comparative microstructural changes in brain at late delayed phase of radiation injury using Diffusion Tensor Imaging (DTI) technique. Region of interest (ROIs) were drawn on corpus callosum (CC), hippocampus (HIP), sensory-motor cortex (SMC), thalamus (TH), hypothalamus (HTH), cingulum (CG), caudeto-putamen (CUP) and cerebral peduncle (CP). The differences in FA (Fractional Anisotropy) and MD (Mean Diffusivity) values generated from these regions of all the groups were evaluated by ANOVA with multiple comparisons using Bonferroni, Post Hoc test. Maximum changes have been observed in MD values mainly in cranial group showing significantly increased MD in CC and SMC region while both the groups showed changes in TH and CUP region as compared to control. FA showed more prominent changes in whole body radiation group than cranial group by decreasing significantly in CP region while in HTH and CUP region in both the groups. Reduced FA indicates compromised structural integrity due to the loss of glial progenitor cells causing transient demyelination while increased MD has been equated with cellular membrane disruption, cell death and vasogenic edema. Thus, present study reveals late delayed CNS response after cranial and whole body radiation exposure. These findings can help us differentiate and monitor the pathophysiological changes at later stages either due to accidental or intentional exposure to ionizing radiation

  3. The influence of small dose radiation on some molecular and genetic parameters of peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Mel'nov, S.B.; Morozik, P.M.

    2001-01-01

    About 70% of Chernobyl radionuclide fallout was spread on the territory of Belarus. As a result, 2,5 million people now are living in contaminated areas under the pressure of the additional influence of low dose radiation. The aim of the current research is to definite the effects of this factor on some molecular and genetic characteristics of the children - prominent residents of the contaminated areas

  4. Genetic effects of mammal exposure to ionizing radiation: topical aspects of the problem (review of the literature)

    International Nuclear Information System (INIS)

    Nefedov, I.Yu.; Nefedova, I.Yu.; Palyga, G.F.

    2000-01-01

    The genetic effects of participating the irradiated males and nonirradiated females, irradiated females and nonirradiated males as well as both irradiated parents in gametes impregnation are analyzed and summarized in the literature review. The interconnection between the conditions of external radiation effect on gametogenesis of parents and the progeny effects in the embryogenesis and after the birth is traced. The sequence of change in genetic radiovulnerability of gametes at various stages of spermatogenesis and oogenesis and their combinations by participation of two irradiated parents in the gametes impregnation is shown. Some general regularities in the hereditary effects of the mammals irradiation are formulated [ru

  5. Some chemical influence on genetic effects of ionizing radiation and biodosimetry problems

    International Nuclear Information System (INIS)

    Mosse, I.B.

    2007-01-01

    Complete text of publication follows. Radiation sensitivity is a quantitative character from genetic point of view and the distribution of this character values in populations is characterized by a binomial curve. So, 50% of the population have the mean values of radiosensitivity (x ± 0.67σ), 95% of individuals have radiosensitivity values equal to x ± 1.96σ and 5% of the population have this characters ranged from x ± 1.96σ to x ± 3σ, with division into the supersensitive fraction (2.5%) and the superresistant one (2.5%). Radiosensitivity as well as other quantitative characters is caused by the interaction of some pairs of polymeric genes determining a lot of physiological and biochemical organism features. Thus, irradiation in the same dose can induce different level of mutations or other biological effects in different humans. Besides, radiosensitivity depends to a great degree upon environmental factors. For instance, a level of radiosensitivity depends on physical activity, nervous and psychological state, hormonal balance etc. A diet can change an individual radioresistance - food rich in vitamins, microelements, adaptogens and so on favors the increase in individual radioresistance. Many food stuffs contain radioprotectors or antimutagens. So, tea, coffee, cocoa, chocolate, mushrooms and other products have melanin, which is a very effective radioprotector not only against acute irradiation, but even against chronic one according to out data. On the contrary some substances in our food such as residual amounts of fertilizers or herbicides can be mutagenic or increase mutagenic action of radiation. In the last case we observed synergetic or antagonistic effects. Radioadaptive response is one of the most significant factors which can be responsible for uncorrected radiation dose evaluation by biodosimetry methods. This phenomenon decreases effects of ionizing radiation approximately twice. Adaptive reaction can be induced by low radiation dose as well

  6. Genetic risks from radiation: recent assessments by the BEIR and UNSCEAR Committees and suggestions as to how future research can improve such estimates

    International Nuclear Information System (INIS)

    Selby, P.B.

    1979-01-01

    Recently two widely-recognized committees, namely the UNSCEAR and BEIR Committees, have reevaluated their estimates of genetic risks from radiation. Their estimates for gene mutations are based on two different approaches, one being the doubling-dose approach and the other being a new direct approach based on an empirical determination of the amount of dominant induced damage in the skeletons of mice in the first generation following irradiation. The estimates made by these committees are in reasonably good agreement and suggest that the genetic risks from present exposures resulting from nuclear power production are small. There is room for much improvement in the reliability of the risk estimates. The relatively new approach of measuring the amount of induced damage to the mouse skeleton shows great promise of improving knowledge about how changes in the mutation frequency affect the incidence of genetic disorders. Such findings may have considerable influence on genetic risk estimates for radiation and on the development of risk estimates for other less-well-understood environmental mutagens

  7. Somatic and genetic effects of gamma radiation on Japanese quail (Coturnix coturnix japonica) and hen (Gallus gallus domestica)

    International Nuclear Information System (INIS)

    Baumgartner, J.

    1982-01-01

    Genetic changes were studied in economically significant species of birds and the impact of gamma radiation on their organisms in general. The impact is dealt with of small, medium and high doses of radiation on gonadal cells in vivo and in vitro and on fertilized eggs, and the total impact on the organism. During the irradiation of embryos toxic effects were unambiguously found for exposures to more than 100 R. The embryo was most sensitive between the 2nd and 4th day of development. No cytotoxic effect of radiation was observed in sperms exposed in vitro to less than 10,000 R. Irradiation of gonads affected the reproduction capacity of male birds substantially more than that of female birds. (M.D.)

  8. Genetic approaches in comparative and evolutionary physiology

    Science.gov (United States)

    Bridgham, Jamie T.; Kelly, Scott A.; Garland, Theodore

    2015-01-01

    Whole animal physiological performance is highly polygenic and highly plastic, and the same is generally true for the many subordinate traits that underlie performance capacities. Quantitative genetics, therefore, provides an appropriate framework for the analysis of physiological phenotypes and can be used to infer the microevolutionary processes that have shaped patterns of trait variation within and among species. In cases where specific genes are known to contribute to variation in physiological traits, analyses of intraspecific polymorphism and interspecific divergence can reveal molecular mechanisms of functional evolution and can provide insights into the possible adaptive significance of observed sequence changes. In this review, we explain how the tools and theory of quantitative genetics, population genetics, and molecular evolution can inform our understanding of mechanism and process in physiological evolution. For example, lab-based studies of polygenic inheritance can be integrated with field-based studies of trait variation and survivorship to measure selection in the wild, thereby providing direct insights into the adaptive significance of physiological variation. Analyses of quantitative genetic variation in selection experiments can be used to probe interrelationships among traits and the genetic basis of physiological trade-offs and constraints. We review approaches for characterizing the genetic architecture of physiological traits, including linkage mapping and association mapping, and systems approaches for dissecting intermediary steps in the chain of causation between genotype and phenotype. We also discuss the promise and limitations of population genomic approaches for inferring adaptation at specific loci. We end by highlighting the role of organismal physiology in the functional synthesis of evolutionary biology. PMID:26041111

  9. Genetics researchers’ and iRB professionals’ attitudes toward genetic research review: a comparative analysis

    Science.gov (United States)

    Edwards, Karen L.; Lemke, Amy A.; Trinidad, Susan B.; Lewis, Susan M.; Starks, Helene; Snapinn, Katherine W.; Griffin, Mary Quinn; Wiesner, Georgia L.; Burke, Wylie

    2012-01-01

    Purpose Genetic research involving human participants can pose challenging questions related to ethical and regulatory standards for research oversight. However, few empirical studies describe how genetic researchers and institutional review board (IRB) professionals conceptualize ethical issues in genetic research or where common ground might exist. Methods Parallel online surveys collected information from human genetic researchers (n = 351) and IRB professionals (n = 208) regarding their views about human participant oversight for genetic protocols. Results A range of opinions were observed within groups on most issues. In both groups, a minority thought it likely that people would be harmed by participation in genetic research or identified from coded genetic data. A majority of both groups agreed that reconsent should be required for four of the six scenarios presented. Statistically significant differences were observed between groups on some issues, with more genetic researcher respondents trusting the confidentiality of coded data, fewer expecting harms from reidentification, and fewer considering reconsent necessary in certain scenarios. Conclusions The range of views observed within and between IRB and genetic researcher groups highlights the complexity and unsettled nature of many ethical issues in genome research. Our findings also identify areas where researcher and IRB views diverge and areas of common ground. PMID:22241102

  10. Somatic and genetic effects

    International Nuclear Information System (INIS)

    Broerse, J.J.; Barendsen, G.W.; Kal, H.B.; Kogel, A.J. van der

    1983-01-01

    This book contains the extended abstracts of the contributions of the poster workshop sessions on somatic and genetic effects of the 7th international congress of radiation research. They cover the following main topics: haematopoietic and immune systems, mechanisms of late effects in various tissues, endogenous and exogenous factors in radiation carcinogenesis, teratogenic effects, genetic effects, in vitro transformation, tumour induction in different tissues, carcinogenesis in incorporated tissues, cancer epidemology and risk assessment. refs.; figs.; tabs

  11. Genetic effects in children exposed in prenatal period to ionizing radiation after the Chornobyl nuclear power plant accident.

    Science.gov (United States)

    Stepanova, Ye I; Vdovenko, V Yu; Misharina, Zh A; Kolos, V I; Mischenko, L P

    2016-12-01

    To study the genetic effects in children exposed to radiation in utero as a result of the Chornobyl nuclear power plant accident accounting the total radiation doses and equivalent radiation doses to the red bone marrow. Incidence of minor developmental anomalies was studied in children exposed to radiation in utero (study group) and in the control group (1144 subjects surveyed in total). Cytogenetic tests using the method of differential G-banding of chromosomes were conducted in 60 children of both study and control groups (10-12-year-olds) and repeatedly in 39 adolescents (15-17-year-olds). A direct correlation was found between the number of minor developmental anomalies and fetal dose of radiation, and a reverse one with fetal gestational age at the time of radiation exposure. Incidence of chromosomal damage in somatic cells of 10-12-year-old children exposed prenatally was associated with radiation dose to the red bone marrow. The repeated testing has revealed that an increased level of chromosomal aberrations was preserved in a third of adolescents. The persons exposed to ionizing radiation at prenatal period should be attributed to the group of carcinogenic risk due to persisting increased levels of chromosome damage. This article is a part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

  12. Comparison between fluorescent in-situ hybridisation and array comparative genomic hybridisation in preimplantation genetic diagnosis in translocation carriers.

    Science.gov (United States)

    Lee, Vivian C Y; Chow, Judy F C; Lau, Estella Y L; Yeung, William S B; Ho, P C; Ng, Ernest H Y

    2015-02-01

    To compare the pregnancy outcome of the fluorescent in-situ hybridisation and array comparative genomic hybridisation in preimplantation genetic diagnosis of translocation carriers. Historical cohort. A teaching hospital in Hong Kong. All preimplantation genetic diagnosis treatment cycles performed for translocation carriers from 2001 to 2013. Overall, 101 treatment cycles for preimplantation genetic diagnosis in translocation were included: 77 cycles for reciprocal translocation and 24 cycles for Robertsonian translocation. Fluorescent in-situ hybridisation and array comparative genomic hybridisation were used in 78 and 11 cycles, respectively. The ongoing pregnancy rate per initiated cycle after array comparative genomic hybridisation was significantly higher than that after fluorescent in-situ hybridisation in all translocation carriers (36.4% vs 9.0%; P=0.010). The miscarriage rate was comparable with both techniques. The testing method (array comparative genomic hybridisation or fluorescent in-situ hybridisation) was the only significant factor affecting the ongoing pregnancy rate after controlling for the women's age, type of translocation, and clinical information of the preimplantation genetic diagnosis cycles by logistic regression (odds ratio=1.875; P=0.023; 95% confidence interval, 1.090-3.226). This local retrospective study confirmed that comparative genomic hybridisation is associated with significantly higher pregnancy rates versus fluorescent in-situ hybridisation in translocation carriers. Array comparative genomic hybridisation should be the technique of choice in preimplantation genetic diagnosis cycles in translocation carriers.

  13. Comparative study of Si diodes for gamma radiation dosimetry

    International Nuclear Information System (INIS)

    Pascoalino, Kelly Cristina da Silva

    2010-01-01

    In this work it is presented the comparative study of Si diodes response for gamma radiation dosimetry. The diodes investigated, grown by float zone (Fz) and magnetic Czochralski (MCz) techniques, were processed at the Physics Institute of Helsinki University in the framework of the research and development of rad-hard silicon devices. To study the dosimetric response of these diodes they were connected in the photovoltaic mode to the input of a digital electrometer to measure the photocurrent signal due to the incidence of gamma-rays from a 60 Co source (Gammacell 220). The dosimetric parameter utilized to study the response of these devices was the charge, obtained trough the integration of the current signals, as a function of the absorbed dose. Studies of the influence of the pre-irradiation procedures on both sensitivity and stability of these diodes showed that the sensitivity decreased with the total absorbed dose but after a preirradiation of about 873 kGy they became more stable. Radiation damage effects eventually produced in the devices were monitored trough dynamic current and capacitance measurements after each irradiation step. Both samples also exhibited good response reproducibility, 2,21% (Fz) and 2,94% (MCz), obtained with 13 consecutive measurements of 15 kGy compared with the equivalent 195 kGy absorbed dose in one step of irradiation. It is important to note that these results are better than those obtained with routine polymethylmethacrylate (PMMA) dosimeters used in radiation processing dosimetry. (author)

  14. Stereotactic Body Radiation Therapy Delivery in a Genetically Engineered Mouse Model of Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Du, Shisuo; Lockamy, Virginia [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Zhou, Lin [Department of Thoracic Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan (China); Xue, Christine; LeBlanc, Justin [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Glenn, Shonna [Xstrahl, Inc, Suwanee, Georgia (United States); Shukla, Gaurav; Yu, Yan; Dicker, Adam P.; Leeper, Dennis B. [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Lu, You [Department of Thoracic Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan (China); Lu, Bo, E-mail: bo.lu@jefferson.edu [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania (United States)

    2016-11-01

    Purpose: To implement clinical stereotactic body radiation therapy (SBRT) using a small animal radiation research platform (SARRP) in a genetically engineered mouse model of lung cancer. Methods and Materials: A murine model of multinodular Kras-driven spontaneous lung tumors was used for this study. High-resolution cone beam computed tomography (CBCT) imaging was used to identify and target peripheral tumor nodules, whereas off-target lung nodules in the contralateral lung were used as a nonirradiated control. CBCT imaging helps localize tumors, facilitate high-precision irradiation, and monitor tumor growth. SBRT planning, prescription dose, and dose limits to normal tissue followed the guidelines set by RTOG protocols. Pathologic changes in the irradiated tumors were investigated using immunohistochemistry. Results: The image guided radiation delivery using the SARRP system effectively localized and treated lung cancer with precision in a genetically engineered mouse model of lung cancer. Immunohistochemical data confirmed the precise delivery of SBRT to the targeted lung nodules. The 60 Gy delivered in 3 weekly fractions markedly reduced the proliferation index, Ki-67, and increased apoptosis per staining for cleaved caspase-3 in irradiated lung nodules. Conclusions: It is feasible to use the SARRP platform to perform dosimetric planning and delivery of SBRT in mice with lung cancer. This allows for preclinical studies that provide a rationale for clinical trials involving SBRT, especially when combined with immunotherapeutics.

  15. Genetic radiation effects of Hiroshima and Nagasaki atomic bombs

    International Nuclear Information System (INIS)

    Srsen, S.

    1984-01-01

    A group of researchers examined persons who had survived the Hiroshima and Nagasaki bombs and were irradiated and their progeny with the aim of getting an idea of the genetic effects of these explosions. Teratogenic effects are not discussed. In the lymphocytes of the peripheral blood of persons who had been exposed to high dose irradiation the researchers found a significant increase in chromosomal aberrations by conventional and more recent methods of chromosomal analysis. In parents who had survived the atomic holocaust there were no significant deviations as against the rest of the population in still births, neonatal defects, infant mortality, and mortality of first generation progeny, in neonate weight, the sex ratio, increased occurence of leukosis and chromosomal aberrations in their children. These negative findings in the first generation do not signify that there is no danger from atomic bomb blasts for human kind. They only indicate that the effects of radiation were to small to be found by routine methods or that the methods used were not suitable

  16. Genetic radiation effects of Hiroshima and Nagasaki atomic bombs

    Energy Technology Data Exchange (ETDEWEB)

    Srsen, S. (Komenskeho Univ., Bratislava (Czechoslovakia). Lekarska Fakulta)

    1984-05-01

    A group of researchers examined persons who had survived the Hiroshima and Nagasaki bombs and were irradiated and their progeny with the aim of getting an idea of the genetic effects of these explosions. Teratogenic effects are not discussed. In the lymphocytes of the peripheral blood of persons who had been exposed to high dose irradiation the researchers found a significant increase in chromosomal aberrations by conventional and more recent methods of chromosomal analysis. In parents who had survived the atomic holocaust there were no significant deviations as against the rest of the population in still births, neonatal defects, infant mortality, and mortality of first generation progeny, in neonate weight, the sex ratio, increased occurence of leukosis and chromosomal aberrations in their children. These negative findings in the first generation do not signify that there is no danger from atomic bomb blasts for human kind. They only indicate that the effects of radiation were too small to be found by routine methods or that the methods used were not suitable.

  17. Environmental and genetic interactions in human cancer

    International Nuclear Information System (INIS)

    Paterson, M.C.

    Humans, depending upon their genetic make-up, differ in their susceptibility to the cancer-causing effects of extrinsic agents. Clinical and laboratory studies on the hereditary disorder, ataxia telangiectasia (AT) show that persons afflicted with this are cancer-prone and unusually sensitive to conventional radiotherapy. Their skin cells, when cultured, are hypersensitive to killing by ionizing radiation, being defective in the enzymatic repair of radiation-induced damange to the genetic material, deoxyribonucleic acid (DNA). This molecular finding implicates DNA damage and its imperfect repair as an early step in the induction of human cancer by radiation and other carcinogens. The parents of AT patients are clincally normal but their cultured cells are often moderately radiosensitive. The increased radiosensitivity of cultured cells offers a means of identifying a presumed cancer-prone subpopulation that should avoid undue exposure to certain carcinogens. The radioresponse of cells from patients with other cancer-associated genetic disorders and persons suspected of being genetically predisposed to radiation-induced cancer has also been measured. Increased cell killing by γ-rays appears in the complex genetic disease, tuberous sclerosis. Cells from cancer-stricken members of a leukemia-prone family are also radiosensitive, as are cells from one patient with radiation-associated breast cancer. These radiobiological data, taken together, strongly suggest that genetic factors can interact with extrinsic agents and thereby play a greater causative role in the development of common cancers in man than previously thought. (L.L.)

  18. The genetic basis of strain-dependent differences in the early phase of radiation injury in mouse lung

    International Nuclear Information System (INIS)

    Franko, A.J.; Sharplin, J.; Ward, W.F.; Hinz, J.M.

    1991-01-01

    Substantial differences between mouse strains have been reported in the lesions present in the lung during the early phase of radiation injury. Some strains show only classical pneumonitis, while other strains develop substantial fibrosis and hyaline membranes which contribute appreciably to respiratory insufficiency, in addition to pneumonitis. Other strains are intermediate between these extremes. These differences correlate with intrinsic differences in activities of lung plasminogen activator and angiotensin converting enzyme. The genetic basis of these differences was assessed by examining histologically the early reaction in lungs of seven murine hybrids available commercially after whole-thorax irradiation. Crosses between fibrosing and nonfibrosing parents were uniformly nonfibrosing, and crosses between fibrosing and intermediate parents were uniformly intermediate. No evidence of sex linkage was seen. Thus the phenotype in which fibrosis is found is controlled by autosomal recessive determinants. Strains prone to radiation-induced pulmonary fibrosis and hyaline membranes exhibited intrinsically lower activities of lung plasminogen activator and angiotensin converting enzyme than either the nonfibrosing strains or the nonfibrosing hybrid crosses. The median time of death of the hybrids was genetically determined primarily by the longest-lived parent regardless of the types of lesions expressed

  19. Genetic radiation risks: a neglected topic in the low dose debate

    Directory of Open Access Journals (Sweden)

    Inge Schmitz-Feuerhake

    2016-01-01

    Full Text Available Objectives To investigate the accuracy and scientific validity of the current very low risk factor for hereditary diseases in humans following exposures to ionizing radiation adopted by the United Nations Scientific Committee on the Effects of Atomic Radiation and the International Commission on Radiological Protection. The value is based on experiments on mice due to reportedly absent effects in the Japanese atomic bomb (Abomb survivors. Methods To review the published evidence for heritable effects after ionising radiation exposures particularly, but not restricted to, populations exposed to contamination from the Chernobyl accident and from atmospheric nuclear test fallout. To make a compilation of findings about early deaths, congenital malformations, Down’s syndrome, cancer and other genetic effects observed in humans after the exposure of the parents. To also examine more closely the evidence from the Japanese A-bomb epidemiology and discuss its scientific validity. Results Nearly all types of hereditary defects were found at doses as low as one to 10 mSv. We discuss the clash between the current risk model and these observations on the basis of biological mechanism and assumptions about linear relationships between dose and effect in neonatal and foetal epidemiology. The evidence supports a dose response relationship which is non-linear and is either biphasic or supralinear (hogs-back and largely either saturates or falls above 10 mSv. Conclusions We conclude that the current risk model for heritable effects of radiation is unsafe. The dose response relationship is non-linear with the greatest effects at the lowest doses. Using Chernobyl data we derive an excess relative risk for all malformations of 1.0 per 10 mSv cumulative dose. The safety of the Japanese A-bomb epidemiology is argued to be both scientifically and philosophically questionable owing to errors in the choice of control groups, omission of internal exposure effects and

  20. Perinatal radiation exposure due to nuclear medical use of radioactive compounds

    International Nuclear Information System (INIS)

    Gloebel, B.

    1982-01-01

    When the pregnancy is yet undetected, radiation doses were only relevant when given within therapeutic application. Only Hg 203-chloromerodrine and J 131-iodide are relevant for newborns as they cause radiation doses of 40-70 rad. in the organ concerned. As a result of nuclear medicine and the application of radio nuclides not only patients but also ''occupationally exposed'' persons and parts of the population are exposed to radiation. Pregnant women are not admitted in control areas but can only be forbidden to enter when the pregnancy has been established. This is the case after six weeks. The occupational perinatal exposure is therefore about 11% of the annual dose. Evaluation of the figures for exposure to radiation can be done by either comparing them with natural exposure or by estimating the risks. The somatic radiation risk per rad is of the 5th order, the genetic risk of the 4th to 6th order as compared with a spontaneous genetic risk of the 2nd order. According to surveys of STIEVE (1976) the risk involved in various diagnostic and therapeutic measures of complications not due to radiation exposure is of 2nd to fifth order. On an average, the risks of diagnostic measures in nuclear medicine are small in comparison to the radiation risk. A comparison with the range of natural radiation exposure also indicated that only exposures which exceed natural exposure of 0.4 rad have to be considered. (orig.) [de

  1. Involved-nodal radiation therapy leads to lower doses to critical organs-at-risk compared to involved-field radiation therapy

    International Nuclear Information System (INIS)

    Mulvihill, David J.; McMichael, Kevin; Goyal, Sharad; Drachtman, Richard; Weiss, Aaron; Khan, Atif J.

    2014-01-01

    Background: Involved field radiotherapy (IFRT) after cytotoxic chemotherapy has become the standard of care in treating pediatric patients with Hodgkin lymphoma. However, recent interest in shrinking the treatment volume to involved node radiotherapy (INRT) may allow lower doses to critical organ structures. We dosimetrically compared IFRT and INRT treatment approaches. Methods: INRT treatment plans were retrospectively constructed from 17 consecutively treated pediatric patients identified with Hodgkin lymphoma who had been previously treated with conventional IFRT. The radiation doses delivered to organs-at-risk (OARs) with virtual INRT treatment plans based on INRT field design were then compared to the original IFRT treatment plans. Metrics for comparison included mean doses to organs and volumes of organ receiving at least 50% of the original prescription dose (V50%). A one-tailed, paired t-test was then performed to verify statistical significance at an alpha level of 0.05. Results: All organs at risk compared in this investigation (kidneys, heart, thyroid, parotids, and lungs) had significantly lower doses of radiation with INRT when compared to IFRT (p < 0.05). Furthermore, the volume of the breast receiving at least 50% of the initial prescription dose was statistically lower in the INRT plans. Conclusions: Utilizing the concept of INRT results in a reduction of radiation dose to critical organ structures in pediatric patients with Hodgkin lymphoma when compared to the more traditional method of IFRT

  2. A note on the relevance of human population genetic variation and molecular epidemiology to assessing radiation health risk for space travellers

    International Nuclear Information System (INIS)

    Brackley, M.E.; Curry, J.; Glickman, B.W.

    1999-01-01

    We discuss the relevance to space medicine of studies concerning human genetic variation and consequent variable disease susceptibility or sensitivity between individuals. The size of astronaut and cosmonaut populations is both presently and cumulatively small, and despite the launch of the International Space Station, unlikely to increase by orders of magnitude within the foreseeable future. In addition, astronauts-cosmonauts constitute unrepresentative samples of their national populations. While the context of exposure for the astronaut-cosmonaut group is one unlikely to be replicated elsewhere than in space, aspects of specific exposures may be simulated by events such as occupational radiation exposure or radiation therapy. Hence, population-based studies of genetic susceptibility or sensitivity to disease, especially where it is precipitated by events that may simulate consequences of the space environment, likely will prove of value in assessing long-term health risks

  3. Preimplantation genetic diagnosis and screening by array comparative genomic hybridisation: experience of more than 100 cases in a single centre.

    Science.gov (United States)

    Chow, J Fc; Yeung, W Sb; Lee, V Cy; Lau, E Yl; Ho, P C; Ng, E Hy

    2017-04-01

    Preimplantation genetic screening has been proposed to improve the in-vitro fertilisation outcome by screening for aneuploid embryos or blastocysts. This study aimed to report the outcome of 133 cycles of preimplantation genetic diagnosis and screening by array comparative genomic hybridisation. This study of case series was conducted in a tertiary assisted reproductive centre in Hong Kong. Patients who underwent preimplantation genetic diagnosis for chromosomal abnormalities or preimplantation genetic screening between 1 April 2012 and 30 June 2015 were included. They underwent in-vitro fertilisation and intracytoplasmic sperm injection. An embryo biopsy was performed on day-3 embryos and the blastomere was subject to array comparative genomic hybridisation. Embryos with normal copy numbers were replaced. The ongoing pregnancy rate, implantation rate, and miscarriage rate were studied. During the study period, 133 cycles of preimplantation genetic diagnosis for chromosomal abnormalities or preimplantation genetic screening were initiated in 94 patients. Overall, 112 cycles proceeded to embryo biopsy and 65 cycles had embryo transfer. The ongoing pregnancy rate per transfer cycle after preimplantation genetic screening was 50.0% and that after preimplantation genetic diagnosis was 34.9%. The implantation rates after preimplantation genetic screening and diagnosis were 45.7% and 41.1%, respectively and the miscarriage rates were 8.3% and 28.6%, respectively. There were 26 frozen-thawed embryo transfer cycles, in which vitrified and biopsied genetically transferrable embryos were replaced, resulting in an ongoing pregnancy rate of 36.4% in the screening group and 60.0% in the diagnosis group. The clinical outcomes of preimplantation genetic diagnosis and screening using comparative genomic hybridisation in our unit were comparable to those reported internationally. Genetically transferrable embryos replaced in a natural cycle may improve the ongoing pregnancy rate

  4. Genetic predisposition for radiation-induced bone tumors

    International Nuclear Information System (INIS)

    Rosemann, M.; Luz, A.; Kuosaite, V.; Favor, J.; Atkinson, M.J.; Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg

    1999-01-01

    The interaction between environmental factors and genetic determinants is crucial for the development of malignant tumours. However, the hereditary factors involved in the development of cancer that have been recognised so far are only responsible for at the most ten percent of tumours. It is still a matter of dispute whether the remaining 90 percent - so-called sporadic tumours - really have a cause that is free of genetic influence. There are good reasons for believing that there are a large number of genes in the human genome that confer resistance or susceptibility for tumorigenesis, and thus lead to natural genetic variability. (orig.) [de

  5. Comparative data in the radiation-induced yields of cytogenetic alterations

    International Nuclear Information System (INIS)

    Koeteles, G.J.

    1993-01-01

    The need of biological indicators of radiation injuries is growing for various conditions of exposures like external or internal, acute or chronic. The search for such indicators did not result in techniques fulfilling yet all these requirements. So far, the dielectric chromosome aberration analysis can be used as the most reliable assay in radiation accidents. In the recent years several laboratories including ours have initiated research to apply a more simple cytogenetic technique, i.e. the detection of micronuclei in lymphocytes. The fairly consequent dose-effect relationships obtained by several laboratories made the technique rather promising, especially after the modification recommended to recognize interphase cells after their first mitotic divisions. In this presentation dose-effect relationships of formations of various cytogenetic abnormalities are compared with special emphasis on their applicabilities in dose assessments in radiation accidents. Basically, the materials and methods were as published earlier

  6. Genetic effects of low-level irradiation

    International Nuclear Information System (INIS)

    Selby, P.B.

    1980-01-01

    Recent estimates of the genetic effects of radiation by two widely recognized committees (BEIR III and UNSCEAR 1977) are based to a large extent on data collected in mice using either the specific-locus method or the approach of empirically determining the nature and extent of radiation-induced genetic damage to the skeleton. Both committees made use of doubling-dose and direct methods of estimating genetic hazard. Their estimates can be applied to assessments of risk resulting from medical irradiation in terms both of risk to the population at large and to the individual

  7. Comparative analysis of intraluminal radiation stent in treatment of advanced esophageal carcinoma

    International Nuclear Information System (INIS)

    Guo Jinhe; Teng Gaojun; Zhu Guangyu; He Shicheng; Fang Wen; Deng Gang; Li Guozhao

    2007-01-01

    Objective: To compare the clinical effectiveness of intraluminal radiation stent with that of common covered stent to palliate dysphagia in advanced esophageal cancer. Methods: Fifty three cases were randomly assigned to the experimental group (Group A, n=27) and the control group (Group B, n26). Radiation stents were placed in Group A and common covered stents were placed in Group B. A randomized trial was performed to compare the two groups with respect to complications, relief of dysphagia, and overall survival period. Results: The placement of stents were successful in all the 53 patients. In Group A, no leakage of radiation source was observed through ECT examination, and no displacement of radiation seeds was found through radiography. The follow-up CT showed reduced lesion size compared to presurgical lesion. Three of the 5 patients who underwent uncovered radiation stent placement showed complete necrosis and inflammatory hyperblastosis in tumor tissue adjacent to radiation particles at 2 months follow-up. The lumen of the stents were smooth and had no overgrowth of tumor tissue. Granulation hyperplasia was found at both ends of the stents, prominent at the proximal ends, The incidence of stent- related complications had no significant difference between group A and group B (test, P>0.05). Dysphasia resolved significantly after stent placement in both groups. The improvement of dysphasia was more significant in Group A than in Group B after 2 months of stent placement (1.37±0.56 in group A, 1.82±0.50 in group B,P=0.004). The median survival period was longer in Group A than in Group B (7 months vs 4 months ). The mean survival period was also longer in Group A than in Group B (8.3 months vs 3.5 months). There was a statistically significant difference in the survival period between the two groups (P<0.01). Conclusion: Intraluminal radiation esophageal stent can not only palliate dysphagia but also restrain tumor growth. Palliation period of dysphagia and

  8. Development of radiation-induced mutation techniques and functional genomics studies

    International Nuclear Information System (INIS)

    Kim, Dong Sub; Kang, Si Yong; Kim, Jin Baek

    2012-01-01

    This project has been performed to develop plant genetic resources using radiation (gamma-rays, ion-beam, space environments), to conduct functional genomics studies with mutant resources, and to develop new radiation plant breeding techniques using various radiation sources during 3 years. In the first section, we developed flower genetic resources, functional crop resources, and bio-industrial plant resources. In the second section, we cloned several mutated genes and studied mechanisms of gene expression and genetic diversity of mutations induced by gamma-rays. In the third section, we developed new plant breeding techniques using gamma-phytotron, heavy ion-beam, and space environments. Based on these results, a total of 8 cultivars containing Chrysanthemum, Hibiscus, kenaf, rice, and soybean were applied for plant variety protection (PVP) and a total of 4 cultivars were registered for PVP. Also, license agreement for the dwarf type Hibiscus mutant 'Ggoma' was conducted with Supro co. and the manufacturing technology for natural antioxidant pear-grape vinegar was transferred into Enzenic co. Also, 8 gene sequences, such as F3'H and LDOX genes associated with flower color in Chrysanthemum and EPSPS gene from Korean lawn grass, were registered in the database of National Center for Biotechnology Information (NCBI). In the future study, we will develop new radiation mutation breeding techniques through the mutation spectrum induced by various radiation sources, the studies for mechanism of the cellular response to radiation, and the comparative·structural·functional genomics studies for useful traits

  9. Studies on assessment of health effects of radiation processed foods: Part 1. genetic toxicological evaluation in somatic and germ cells of laboratory animals

    Energy Technology Data Exchange (ETDEWEB)

    Chaubey, R C; Aravindakshan, M; Chauhan, P S [Genetic Toxicology and Chromosome Studies Section, Cell Biology Div., Bhabha Atomic Research Centre, Mumbai (India)

    1999-09-01

    The studies summarized in this report form a part of the program on the safety evaluation of radiation-processed foods, an important component of the development of radiation technology for food preservation from the public health point of view. These studies contributed significantly and critically to the acceptance of safety of radiation processed foods by regulatory agencies both at the national and international levels. This report contains only genetic studies, one aspect of this program, while the remaining studies will be summarized in a separate report.

  10. Studies on assessment of health effects of radiation processed foods: Part 1. genetic toxicological evaluation in somatic and germ cells of laboratory animals

    International Nuclear Information System (INIS)

    Chaubey, R.C.; Aravindakshan, M.; Chauhan, P.S.

    1999-09-01

    The studies summarized in this report form a part of the program on the safety evaluation of radiation-processed foods, an important component of the development of radiation technology for food preservation from the public health point of view. These studies contributed significantly and critically to the acceptance of safety of radiation processed foods by regulatory agencies both at the national and international levels. This report contains only genetic studies, one aspect of this program, while the remaining studies will be summarized in a separate report

  11. Effects of plasma radiation on wound healing compared with X-ray

    Energy Technology Data Exchange (ETDEWEB)

    Azorin V, E.; Pena E, R. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Azorin V, J. C., E-mail: erica.azorin@inin.gob.mx [Universidad de Guanajuato, Campus Leon, Departamento de Ingenieria Fisica, Blvd. Prol. Calz. de los Heroes No. 908, Col. La Martinica, Leon, Guanajuato (Mexico)

    2015-10-15

    Full text: The radiation emitted by the plasma needle has shown high efficiency in the inactivation of microorganisms and the acceleration of the healing process; apparently such effects are related to the antioxidant activity, induction of cell damage and the generation of free radicals. To take advantage of plasma clinical applications it is essential to understand the cellular mechanisms activated by the exposure of human cells to radiation emitted by cold plasma. In this work we present the results of the characterization of the responses of human skin fibroblasts exposed to the radiation emitted by a plasma by varying the magnitude of flow, electrical power, time and composition of the cell culture medium comparing it with the response of these fibroblasts to low energy X-rays. (Author)

  12. Effects of plasma radiation on wound healing compared with X-ray

    International Nuclear Information System (INIS)

    Azorin V, E.; Pena E, R.; Azorin V, J. C.

    2015-10-01

    Full text: The radiation emitted by the plasma needle has shown high efficiency in the inactivation of microorganisms and the acceleration of the healing process; apparently such effects are related to the antioxidant activity, induction of cell damage and the generation of free radicals. To take advantage of plasma clinical applications it is essential to understand the cellular mechanisms activated by the exposure of human cells to radiation emitted by cold plasma. In this work we present the results of the characterization of the responses of human skin fibroblasts exposed to the radiation emitted by a plasma by varying the magnitude of flow, electrical power, time and composition of the cell culture medium comparing it with the response of these fibroblasts to low energy X-rays. (Author)

  13. Multiobjective optimization of the synchrotron radiation source 'Siberia-2' lattice using a genetic algorithm

    International Nuclear Information System (INIS)

    Korchuganov, V.N.; Smygacheva, A.S.; Fomin, E.A.

    2018-01-01

    One of the best ways to design, research and optimize accelerators and synchrotron radiation sources is to use numerical simulation. Nevertheless, very often during complex physical process simulation considering many nonlinear effects the use of classical optimization methods is difficult. The article deals with the application of multiobjective optimization using genetic algorithms for accelerators and light sources design. These algorithms allow both simple linear and complex nonlinear lattices to be efficiently optimized when obtaining the required facility parameters.

  14. Background radiation

    International Nuclear Information System (INIS)

    Arnott, D.

    1985-01-01

    The effects of background radiation, whether natural or caused by man's activities, are discussed. The known biological effects of radiation in causing cancers or genetic mutations are explained. The statement that there is a threshold below which there is no risk is examined critically. (U.K.)

  15. Sterilization by ionizing radiation comparative evaluation

    International Nuclear Information System (INIS)

    Tata, A.; Giuliani, S.

    1996-01-01

    Sterilization of surgical and medical devices by ionizing radiation (gamma or accelerated electron beams) is currently regarded as one of the main industrial-scale applications of radiation technology processes. Considering the most widely utilized chemical-physical methods (i.e. ethylene oxide (EtO) fumigation and radiation treatment), about 10-12 millions m(3) of surgical and medical devices are estimated to be processed yearly all around the world, of which 7 on beams. Due to the increasing demand for reusable and single-use devices, and the need of assuring their sterility in order to prevent, as much as possible, the diffusion of serious infective diseases (among which for instance Aids), the market of sterilization of these items is considerably expanding. In the general depicted scenario, radiation technologies are expected to gain a leading role, even a part from their economic attractiveness, as an alternative to EtO treatment, which is more and more considered as responsible for increasing environmental, social and public health problems

  16. Some aspects of the genetic consequences of the Chernobyl disaster

    International Nuclear Information System (INIS)

    Shevchenko, V.A.

    1989-01-01

    This paper reports on a study of the genetic effects of ionizing radiations resulting from the Chernobyl disaster. It involves application of the laboratory radiosensitive test-objects for the biological dosimetry of the environment; evaluation of primary radiation-genetic effects resulting from the ionizing irradiation of plant and animal populations within the 30-km vicinity and outside this zone; and a study of distant genetic consequences of ionizing radiation exposure (in a number of generations) on the environmental objects

  17. Environmental Contamination Genetic Consequences Monitoring on the Former Semipalatinsk Test Site: General Approach

    International Nuclear Information System (INIS)

    Seisebaev, A.T.; Bakhtin, M.M.; Zhapbasov, R.Zh.

    1998-01-01

    For an objective assessment of nuclear test consequences for the environment it is necessary, together with the investigation of radiation situation, to study live biological systems, particularly the genetic effects of chronic ionizing radiation. The long staying of plants and animals on the territories with the elevated radiation background level can lead to the change of organism genetic system. In this connection the monitoring of chronically exposed natural populations is of particular interest and can serve as the objective indicator of the scale of natural biota genetic damage. Basing on the results obtained during plant and animal studies one can indirectly assess the hazard of people genetic damage. Besides, studying the mutational process on natural populations exposed to the chronic ionizing radiation one can reveal new regularities, which are impossible to be detected in the laboratory conditions, and new aspects of radiation genetics. The issue of radiation adaptation of organisms affected by the various doses of ionizing radiation is very acute. The prerequisite of organism adaptation to the certain radiation background is genetic heterogeneity of individuals comprising the population and selection of radiation-induced individuals, which are the carriers of the mutation of high radioresistance. The uniqueness of the Semipalatinsk Test site and the necessity of long-term investigations of the nuclear test consequences for the environment demand the elaboration of principles for organization and utilization of natural population genetic monitoring. Radiation-genetic monitoring is the long-term observation of palpitation gene pool conditions, assessment and forecast of their spatial and time alteration, determination of limits of changes admitted under the condition of environmental radioactive contamination. It includes a series of the main research directions and has quite certain methodological peculiarities. In this paper we discuss the tasks of

  18. CHROMOSPHERIC HEATING BY ACOUSTIC WAVES COMPARED TO RADIATIVE COOLING

    Energy Technology Data Exchange (ETDEWEB)

    Sobotka, M.; Heinzel, P.; Švanda, M.; Jurčák, J. [Astronomical Institute, Academy of Sciences of the Czech Republic (v.v.i.), Fričova 298, 25165 Ondřejov (Czech Republic); Del Moro, D.; Berrilli, F. [Department of Physics, University of Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Rome (Italy)

    2016-07-20

    Acoustic and magnetoacoustic waves are among the possible candidate mechanisms that heat the upper layers of the solar atmosphere. A weak chromospheric plage near the large solar pore NOAA 11005 was observed on 2008 October 15, in the Fe i 617.3 nm and Ca ii 853.2 nm lines of the Interferometric Bidimemsional Spectrometer attached to the Dunn Solar Telescope. In analyzing the Ca ii observations (with spatial and temporal resolutions of 0.″4 and 52 s) the energy deposited by acoustic waves is compared to that released by radiative losses. The deposited acoustic flux is estimated from the power spectra of Doppler oscillations measured in the Ca ii line core. The radiative losses are calculated using a grid of seven one-dimensional hydrostatic semi-empirical model atmospheres. The comparison shows that the spatial correlation of the maps of radiative losses and acoustic flux is 72%. In a quiet chromosphere, the contribution of acoustic energy flux to radiative losses is small, only about 15%. In active areas with a photospheric magnetic-field strength between 300 and 1300 G and an inclination of 20°–60°, the contribution increases from 23% (chromospheric network) to 54% (a plage). However, these values have to be considered as lower limits and it might be possible that the acoustic energy flux is the main contributor to the heating of bright chromospheric network and plages.

  19. Comparing radiation exposure during percutaneous vertebroplasty using one- vs. two-fluoroscopic technique

    Directory of Open Access Journals (Sweden)

    Li Yen-Yao

    2013-01-01

    Full Text Available Abstract Background Percutaneous vertebroplasty (PV requires relatively lengthy fluoroscopic guidance, which might lead to substantial radiation exposure to patients or operators. The two-fluoroscopic technique (two-plane radiographs obtained using two fluoroscopes during PV can provide simultaneous two-planar projections with reducing operative time. However, the two-fluoroscopic technique may expose the operator or patient to increased radiation dose. The aim of this study was to quantify the amount of radiation exposure to the patient or operator that occurs during PV using one- vs. two-fluoroscopic technique. Methods Two radiation dosimeters were placed on the right flank of each patient and on the upper sternum of each operator during 26 single-level PV procedures by one senior surgeon. The use of two-fluoroscopic technique (13 patients and one-fluoroscopic technique (13 patients were allocated in a consecutive and alternative manner. The operative time and mean radiation dose to each patient and operator were monitored and compared between groups. Results Mean radiation dose to the patient was 1.97 ± 1.20 mSv (95% CI, 0.71 to 3.23 for the one-fluoroscopic technique group vs. 0.95 ± 0.34 mSv (95% CI, 0.85 to 1.23 for the two-fluoroscopic technique group (P =0.031. Mean radiation dose to the operator was 0.27 ± 0.12 mSv (95% CI, 0.17–0.56 for the one-fluoroscopic technique group vs. 0.25 ± 0.14 mSv (95% CI, 0.06–0.44 for the two-fluoroscopic technique group (P = 0.653. The operative time was significantly different between groups: 47.15 ± 13.48 min (range, 20–75 for the one-fluoroscopic technique group vs. 36.62 ± 8.42 min (range, 21–50 for the two-fluoroscopic technique group (P =0.019. Conclusion Compared to the one-fluoroscopic technique, the two-fluoroscopic technique used during PV provides not only shorter operative times but also reduces the radiation exposure to the patient. There was no

  20. Long-term effects of radiation

    International Nuclear Information System (INIS)

    Smith, J.; Smith, T.

    1981-01-01

    It is pointed out that sources of long-term damage from radiation are two-fold. People who have been exposed to doses of radiation from initial early fallout but have recovered from the acute effects may still suffer long-term damage from their exposure. Those who have not been exposed to early fallout may be exposed to delayed fallout, the hazards from which are almost exclusively from ingesting strontium, caesium and carbon isotopes present in food; the damage caused is relatively unimportant compared with that caused by the brief doses from initial radiation and early fallout. A brief discussion is presented of the distribution of delayed long-lived isotope fallout, and an outline is sketched of late biological effects, such as malignant disease, cataracts, retarded development, infertility and genetic effects. (U.K.)

  1. Involvement of reactive oxygen species (ROS) in the induction of genetic instability by radiation

    International Nuclear Information System (INIS)

    Tominaga, Hideyuki; Kodama, Seiji; Suzuki, Keiji; Watanabe, Masami; Matsuda, Naoki

    2004-01-01

    Radiation generates reactive oxygen species (ROS) that interact with cellular molecules, including DNA, lipids, and proteins. To know how ROS contribute to the induction of genetic instability, we examined the effect of the anti-ROS condition, using both ascorbic acid phosphate (APM) treatment or a low oxygen condition, on the induction of delayed reproductive cell death and delayed chromosome aberrations. The primary surviving colonies of mouse m5S-derived cl. 2011-14 cells irradiated with 6 Gy of X-rays were replated and allowed to form secondary colonies. The anti-ROS treatments were applied to either preirradiation culture or postirradiation cultures for primary or secondary colony formation. Both anti-ROS conditions relieved X-ray-induced acute cell killing to a similar extent. These anti-ROS conditions also relieved genetic instability when those conditions were applied during primary colony formation. However, no effect was observed when the conditions were applied during preirradiation culture and secondary colony formation. We also demonstrated that the amounts of ROS in X-ray-irradiated cells rapidly increase and then decrease at 6 hr postirradiation, and the levels of ROS then gradually decrease to a baseline within 2 weeks. The APM treatment kept the ROS production at a lower level than an untreated control. These results suggest that the cause of genetic instability might be fixed by ROS during a 2-week postirradiation period. (author)

  2. Inferring genetic interactions from comparative fitness data.

    Science.gov (United States)

    Crona, Kristina; Gavryushkin, Alex; Greene, Devin; Beerenwinkel, Niko

    2017-12-20

    Darwinian fitness is a central concept in evolutionary biology. In practice, however, it is hardly possible to measure fitness for all genotypes in a natural population. Here, we present quantitative tools to make inferences about epistatic gene interactions when the fitness landscape is only incompletely determined due to imprecise measurements or missing observations. We demonstrate that genetic interactions can often be inferred from fitness rank orders, where all genotypes are ordered according to fitness, and even from partial fitness orders. We provide a complete characterization of rank orders that imply higher order epistasis. Our theory applies to all common types of gene interactions and facilitates comprehensive investigations of diverse genetic interactions. We analyzed various genetic systems comprising HIV-1, the malaria-causing parasite Plasmodium vivax , the fungus Aspergillus niger , and the TEM-family of β-lactamase associated with antibiotic resistance. For all systems, our approach revealed higher order interactions among mutations.

  3. Dose-effect relationships for malignancy in cells with different genetic characteristics

    International Nuclear Information System (INIS)

    Chadwick, K.H.; Leenhouts, H.P.

    1978-01-01

    By combining the proposals that malignancy behaves as a recessive genetic character, that a somatic mutation is an important step in the development of cancer, and that radiation-induced DNA double-strand breaks are the critical lesions which may lead to cell death, mutation and chromosomal aberrations, considerations can be made and equations derived for the incidence of malignancy in cells having different genotypes. Equations are derived for diploid carrier cells and tetraploid carrier cells, and are compared with data in literature on cell transformation. It is shown that some differences in experimental results could be due to the different genetic character of the cells used. The theoretical considerations are extended to the population which is considered to be constituted of 'carriers' and 'non-carriers' of the recessive malignant genotype. The possible influence of radiation on 'non-carriers' is discussed as are the implications of the presence of two groups within the population for the estimation of risk to low doses of radiation. (author)

  4. Multiparametric assessment of radiation effects for the individual radiation sensitivity estimation

    International Nuclear Information System (INIS)

    2006-01-01

    The effects of low dose irradiation are highly relevant for radiation protection in the public. The sensitivity to clastogenic and tumorigenic effects of ionizing radiation (IR) varies considerably amongst individuals. Examples for genetically determined enhanced sensitivity are well known in some hereditary diseases: patients with chromosomal instability syndromes, Ataxia telangiectasia (A-T), Nijmegen Breakage Syndrome (NBS) and Bloom Syndrome (BS) show strongly enhanced sensitivity towards IR, severe immunodeficiencies, and a high incidence for developing leukemias and lymphomas. This obvious coincidence of enhanced radiosensitivity and tumor risk, and the frequently observed enhanced radiosensitivity of genetically non-defined tumor patients indicate that tumor patients may constitute a subpopulation with enriched genetical predisposition for enhanced radiosensitivity. Furthermore, a subpopulation of radiosensitive individuals may be part of the probably inconspicuous total population. For example, individuals heterozygous for the above mentioned genes (and possibly some other genes) show enhanced radiosensitivity if compared with the normal population. In general, heterozygous carriers of those hereditary deficiencies are clinically inconspicuous, but due an haploinsufficiency their tumour risk may be enhanced. This has been shown for mice carrying an heterozygous Nbs1 mutation (J.-Q. Wang, Lyon, pers. Communication). Our findings concerning enhanced radiation-induced chromosomal aberrations in heterozygous Nbs1 cell lines support this notion. The identification of high risk groups with enhanced radiosensitivity is therefore an important task for radioprotection. This project aimed at establishing a procedure which allows to test various cellular parameters as indicators for effects of radiation. A standard protocol for the isolation and cryoconservation of primary blood cells was developed. DNA repair analysis (Comet Assay) and radiation-induced apoptosis

  5. Genetic effects

    International Nuclear Information System (INIS)

    Kato, Hiroo

    1975-01-01

    In 1948-1953 a large scale field survey was conducted to investigate the possible genetic effects of A-bomb radiation on over 70,000 pregnancy terminations in the cities of Hiroshima and Nagasaki. The indices of possible genetic effect including sex ratio, birth weight, frequency of malformation, stillbirth, neonatal death, deaths within 9 months and anthropometric measurements at 9 months of age for these children were investigated in relation to their parent's exposure status to the A-bomb. There were no detectable genetic effects in this sample, except for a slight change in sex ratio which was in the direction to be expected if exposure had induced sex-linked lethal mutations. However, continued study of the sex ratio, based upon birth certificates in Hiroshima and Nagasaki for 1954-1962, did not confirm the earlier trend. Mortality in these children of A-bomb survivors is being followed using a cohort of 54,000 subjects. No clearly significant effect of parental exposure on survival of the children has been demonstrated up to 1972 (age 17 on the average). On the basis of the regression data, the minimal genetic doubling dose of this type of radiation for mutations resulting in death is estimated at 46 rem for the father and 125 rem for the mother. (auth.)

  6. Perspectives of genetic engineering in radiobiology

    International Nuclear Information System (INIS)

    Khanson, K.P.; Zvonareva, N.B.; Evtushenko, V.I.

    1988-01-01

    Present evidence on the use of genetic engineering methods in studying the molecular mechanism of radiation damage and repair of DNA, as well as radiation mutagenesis and carcinogenesis has been summarized. The new approach to radiobiological research has proved to be extremely fruitful. Some previously unknown types of structural disorders in DNA molecule have been discovered, some repair genes isolated and their primary structure established, some aspects of radiation mutagenesis elucidated, and research into disiphering the molecular bases of neoplastic transformations of exposed cells are being successfully investigated. The perspectives of using genetic engineering methods in radiobiology are discussed

  7. Genetic basis of the sterile insect technique

    International Nuclear Information System (INIS)

    Robinson, A.S.

    2005-01-01

    The use of the sterile insect technique (SIT) for insect control relies on the introduction of sterility in the females of the wild population. This sterility is produced following the mating of these females with released males carrying, in their sperm, dominant lethal mutations that have been induced by ionizing radiation. The reasons why the SIT can only be effective when the induced sterility in the released males is in the form of dominant lethal mutations, and not some form of sperm inactivation, are discussed, together with the relationship of dominant lethal mutations to dose, sex, developmental stage and the particular species. The combination of genetic sterility with that induced by radiation is also discussed in relation to the use of genetic sexing strains of the Mediterranean fruit fly Ceratitis capitata (Wiedemann) in area-wide integrated pest management (AW-IPM) programmes that integrate the SIT. A case is made to lower the radiation dose used in such programmes so as to produce a more competitive sterile insect. Increased competitiveness can also be achieved by using different radiation environments. As well as radiation-induced sterility, natural mechanisms can be recruited, especially the use of hybrid sterility exemplified by a successful field trial with tsetse flies Glossina spp. in the 1940s. Genetic transformation will make some impact on the SIT, especially regarding the introduction of markers for released flies, and the construction of genetic sexing strains. It is concluded that using a physical process, such as radiation, will always have significant advantages over genetic and other methods of sterilization for the large-scale application of the SIT. (author)

  8. Long-term effects of ionizing radiation

    International Nuclear Information System (INIS)

    Kaul, Alexander; Burkart, Werner; Grosche, Bernd; Jung, Thomas; Martignoni, Klaus; Stephan, Guenther

    1997-01-01

    This paper approaches the long-term effects of ionizing radiation considering the common thought that killing of cells is the basis for deterministic effects and that the subtle changes in genetic information are important in the development of radiation-induced cancer, or genetic effects if these changes are induced in germ cells

  9. Detection of the effects of the radiation doses on the genetic material in lymphocytes of samples of workers in Al-Tuwaitha site

    International Nuclear Information System (INIS)

    Muttar, A.G.; Ali, A.K.; Khayon, Sh.K.; Gadban, A.A.; Haider, Y.L.

    2015-01-01

    The present study aims to use the cytogenetic analysis as a bio marker for detection of the effects of the radiation doses on the genetic material in lymphocytes of samples of workers in nuclear facilities destroyed at Al-Tuwaitha site due to decommissioning of radioactive contamination during January to December 2011. Blood samples were collected from workers ,including ( males and females) , aged (25 - 63 years).First test included 35 samples containing 27 males and 8 females, aged ( 34- 63 years) , second test included 27 samples containing 25 males and females, aged (29 - 63 years) and third test included 23 males only .Control group includes 35 samples containing 25 males and 10 females' , aged (30-57 years) who were non smokers and non alcoholics .Four cytogenetic parameters were studied such as chromosomal aberrations, frequency of micronuclei, Mitotic and nuclear division index. The chromosomal aberrations, includes fragment, ring and dicentric chromosome as cytogenetic parameters for biological effects of ionizing radiation. This study showed no significant difference in the rate of chromosomal and chromatid aberrations. Micronuclei and nuclear division index of the workers in the first and second test compared with the groups of workers in the third test, while slightly significant increase at the level (p ≺0.05) when compared with the control group was observed , as well as no significant differences in the rate of mitotic index for workers as compared with the control group was recorded

  10. Physiological and genetics studies of highly radiation-resistant bacteria

    International Nuclear Information System (INIS)

    Keller, L.C.

    1981-01-01

    The phenomenon of radiation resistance was studied using micrococci and Moraxella-Acinetobacter capable of surviving very high doses of gamma radiation which were isolated from foods. Physiological age, or growth phase, was found to be an important factor in making comparisons of radiation-resistance among different bacteria and their mutants. Radiation-resistant bacteria were highly resistant to the lethal effect of nitrosoguanidine used for mutagenesis. Studies of relative resistance of radiation-resistant bacteria, radiation-sensitive mutants, and nonradiation-resistant bacteria to killing by different chemical mutagens did not reveal a correlation between the traits of radiation resistance and mutagen resistance among different strains. Comparisons of plasmid profiles of radiation-resistant bacteria and selected radiation-sensitive mutants suggested the possibility that plasmids may carry genes involved in radiation resistance

  11. Development of radiation-induced mutation techniques and functional genomics studies

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Sub; Kang, Si Yong; Kim, Jin Baek [KAERI, Daejeon (Korea, Republic of); and others

    2012-01-15

    This project has been performed to develop plant genetic resources using radiation (gamma-rays, ion-beam, space environments), to conduct functional genomics studies with mutant resources, and to develop new radiation plant breeding techniques using various radiation sources during 3 years. In the first section, we developed flower genetic resources, functional crop resources, and bio-industrial plant resources. In the second section, we cloned several mutated genes and studied mechanisms of gene expression and genetic diversity of mutations induced by gamma-rays. In the third section, we developed new plant breeding techniques using gamma-phytotron, heavy ion-beam, and space environments. Based on these results, a total of 8 cultivars containing Chrysanthemum, Hibiscus, kenaf, rice, and soybean were applied for plant variety protection (PVP) and a total of 4 cultivars were registered for PVP. Also, license agreement for the dwarf type Hibiscus mutant 'Ggoma' was conducted with Supro co. and the manufacturing technology for natural antioxidant pear-grape vinegar was transferred into Enzenic co. Also, 8 gene sequences, such as F3'H and LDOX genes associated with flower color in Chrysanthemum and EPSPS gene from Korean lawn grass, were registered in the database of National Center for Biotechnology Information (NCBI). In the future study, we will develop new radiation mutation breeding techniques through the mutation spectrum induced by various radiation sources, the studies for mechanism of the cellular response to radiation, and the comparative{center_dot}structural{center_dot}functional genomics studies for useful traits.

  12. DNA repair and radiation sensitivity in mammalian cells

    International Nuclear Information System (INIS)

    Chen, D.J.C.; Stackhouse, M.; Chen, D.S.

    1993-01-01

    Ionizing radiation induces various types of damage in mammalian cells including DNA single-strand breaks, DNA double-strand breaks (DSB), DNA-protein cross links, and altered DNA bases. Although human cells can repair many of these lesions there is little detailed knowledge of the nature of the genes and the encoded enzymes that control these repair processes. We report here on the cellular and genetic analyses of DNA double-strand break repair deficient mammalian cells. It has been well established that the DNA double-strand break is one of the major lesions induced by ionizing radiation. Utilizing rodent repair-deficient mutant, we have shown that the genes responsible for DNA double-strand break repair are also responsible for the cellular expression of radiation sensitivity. The molecular genetic analysis of DSB repair in rodent/human hybrid cells indicate that at least 6 different genes in mammalian cells are responsible for the repair of radiation-induced DNA double-strand breaks. Mapping and the prospect of cloning of human radiation repair genes are reviewed. Understanding the molecular and genetic basis of radiation sensitivity and DNA repair in man will provide a rational foundation to predict the individual risk associated with radiation exposure and to prevent radiation-induced genetic damage in the human population

  13. Radiation dose with digital breast tomosynthesis compared to digital mammography: per-view analysis.

    Science.gov (United States)

    Gennaro, Gisella; Bernardi, D; Houssami, N

    2018-02-01

    To compare radiation dose delivered by digital mammography (FFDM) and breast tomosynthesis (DBT) for a single view. 4,780 FFDM and 4,798 DBT images from 1,208 women enrolled in a screening trial were used to ground dose comparison. Raw images were processed by an automatic software to determine volumetric breast density (VBD) and were used together with exposure data to compute the mean glandular dose (MGD) according to Dance's model. DBT and FFDM were compared in terms of operation of the automatic exposure control (AEC) and MGD level. Statistically significant differences were found between FFDM and DBT MGDs for all views (CC: MGD FFDM =1.366 mGy, MGD DBT =1.858 mGy; ptomosynthesis compared to FFDM. Given the emerging role of DBT, its use in conjunction with synthetic 2D images should not be deterred by concerns regarding radiation burden, and should draw on evidence of potential clinical benefit. • Most studies compared tomosynthesis in combination with mammography vs. mammography alone. • There is some concern about the dose increase with tomosynthesis. • Clinical data show a small increase in radiation dose with tomosynthesis. • Synthetic 2D images from tomosynthesis at zero dose reduce potential harm. • The small dose increase should not be a barrier to use of tomosynthesis.

  14. Los Alamos Science: Number 23, 1995. Radiation protection and the human radiation experiments

    International Nuclear Information System (INIS)

    Cooper, N.G.

    1995-01-01

    There are a variety of myths and misconceptions about the ionizing radiation that surrounds and penetrates us all. Dispel a few of these by taking a leisurely tour of radiation and its properties, of the natural and man-made sources of ionizing radiation, and of the way doses are calculated. By damaging DNA and inducing genetic mutations, ionizing radiation can potentially initiate a cell on the road to cancer. The authors review what is currently known about regulation of cellular reproduction, DNA damage and repair, cellular defense mechanisms, and the specific cancer-causing genes that are susceptible to ionizing radiation. A rapid survey of the data on radiation effects in humans shows that high radiation doses increase the risk of cancer, whereas the effects of low doses are very difficult to detect. The hypothetical risks at low doses, which are estimated from the atomic-bomb survivors, are compared to the low-dose data so that the reader can assess the present level of uncertainty. As part of the openness initiative, ten individuals who have worked with plutonium during various periods in the Laboratory's history were asked to share their experiences including their accidental intakes. The history and prognosis of people who have had plutonium exposures is discussed by the Laboratory's leading epidemiologist

  15. Travel for the 2004 American Statistical Association Biannual Radiation Meeting: "Radiation in Realistic Environments: Interactions Between Radiation and Other Factors

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, David J.

    2009-07-21

    The 16th ASA Conference on Radiation and Health, held June 27-30, 2004 in Beaver Creek, CO, offered a unique forum for discussing research related to the effects of radiation exposures on human health in a multidisciplinary setting. The Conference furnishes investigators in health related disciplines the opportunity to learn about new quantitative approaches to their problems and furnishes statisticians the opportunity to learn about new applications for their discipline. The Conference was attended by about 60 scientists including statisticians, epidemiologists, biologists and physicists interested in radiation research. For the first time, ten recipients of Young Investigator Awards participated in the conference. The Conference began with a debate on the question: “Do radiation doses below 1 cGy increase cancer risks?” The keynote speaker was Dr. Martin Lavin, who gave a banquet presentation on the timely topic “How important is ATM?” The focus of the 2004 Conference on Radiation and Health was Radiation in Realistic Environments: Interactions Between Radiation and Other Risk Modifiers. The sessions of the conference included: Radiation, Smoking, and Lung Cancer Interactions of Radiation with Genetic Factors: ATM Radiation, Genetics, and Epigenetics Radiotherapeutic Interactions The Conference on Radiation and Health is held bi-annually, and participants are looking forward to the 17th conference to be held in 2006.

  16. Exposure to low-dose radiation and the risk of breast cancer among women with a familial or genetic predisposition : a meta-analysis

    NARCIS (Netherlands)

    Jansen-van der Weide, Marijke C.; Greuter, Marcel J. W.; Jansen, Liesbeth; Oosterwijk, Jan C.; Pijnappel, Ruud M.; de Bock, Geertruida H.

    Women with familial or genetic aggregation of breast cancer are offered screening outside the population screening programme. However, the possible benefit of mammography screening could be reduced due to the risk of radiation-induced tumours. A systematic search was conducted addressing the

  17. Exposure to low-dose radiation and the risk of breast cancer among women with a familial or genetic predisposition : a meta-analysis

    NARCIS (Netherlands)

    Jansen-van der Weide, Marijke C.; Greuter, Marcel J. W.; Jansen, Liesbeth; Oosterwijk, Jan C.; Pijnappel, Ruud M.; de Bock, Geertruida H.

    2010-01-01

    Women with familial or genetic aggregation of breast cancer are offered screening outside the population screening programme. However, the possible benefit of mammography screening could be reduced due to the risk of radiation-induced tumours. A systematic search was conducted addressing the

  18. Comparative review of human and canine osteosarcoma: morphology, epidemiology, prognosis, treatment and genetics.

    Science.gov (United States)

    Simpson, Siobhan; Dunning, Mark David; de Brot, Simone; Grau-Roma, Llorenç; Mongan, Nigel Patrick; Rutland, Catrin Sian

    2017-10-24

    Osteosarcoma (OSA) is a rare cancer in people. However OSA incidence rates in dogs are 27 times higher than in people. Prognosis in both species is relatively poor, with 5 year OSA survival rates in people not having improved in decades. For dogs, 1 year survival rates are only around ~ 45%. Improved and novel treatment regimens are urgently required to improve survival in both humans and dogs with OSA. Utilising information from genetic studies could assist in this in both species, with the higher incidence rates in dogs contributing to the dog population being a good model of human disease. This review compares the clinical characteristics, gross morphology and histopathology, aetiology, epidemiology, and genetics of canine and human OSA. Finally, the current position of canine OSA genetic research is discussed and areas for additional work within the canine population are identified.

  19. Estimated values of the genetic and somatic radiation exposure of the Bulgarian population in 1976

    International Nuclear Information System (INIS)

    Poppitz, R.; Dobrev, D.

    1979-01-01

    The genetically and leukemia-significant doses (GSD and LSD) were calculated from the average gonad and bone marrow doses caused by the most frequently applied radiopharmaceuticals in Bulgaria in 1976. Because of the lack of information about the age groups of the patients examined assumptions have been made which led to estimated values of 0.97 mrad for GSD and 2.0 mrad for LSD which must be considered as the upper limit of the real GSD and LSD. The influence of the different radiopharmaceuticals on the average radiation exposure of the population is discussed. (author)

  20. Action of the chlorophyllin before genetic damage induced by gamma radiation in germinal cells of Drosophila

    International Nuclear Information System (INIS)

    Moreno B, R.

    2004-01-01

    The chlorophyllin (CHLN) is a porphyrin of nutritious grade and soluble in water, derived of the chlorophyll. It has been reported that this pigment is a good anti mutagen since it reduces the damage to the DNA caused by physical or chemical agents of direct or indirect action. Their anti carcinogenic action has also been demonstrated when it is administered itself during the induced post-initiation phase by aflatoxins and heterocyclic amines. However in the last decade it has been reported that it also has promoter activity against the genetic damage induced by diverse agents like the alkyl ants of direct and indirect action, the gamma radiation and some heterocyclic amines. This effect has been observed in testing systems like Salmonella, Drosophila, rainbow trout and rodents. In the mouse spermatogonia it has been reported that it reduces the damage to the DNA but with the test of lethal dominant in Drosophila increment the damage induced by gamma radiation. The present study consisted on evaluating the effect of the CHLN in the line germinal masculine of Drosophila by means of the lethal recessive test bound to the sex (LRLS) with the stump Muller 5 and a litters system. Its were pretreated wild males with CHLN and 24 h later were irradiated with 0, 10, 20 and 40 Gy of gamma radiation immediately later were crossed with virgin females of the stump Basc and at 72 h the male was transferred to a cultivation media with three new virgin females, this process repeated three times until completing 3 litters. The F1 it was crossed among itself and in the F2 it was analysed the presence or absence of lethals. The results indicated that the CHLN per se incremented the basal frequency of damage due to the pigment can act as an agent that is inserted to the ADN causing pre mutagenic leisure. Nevertheless with the groups treated with the different doses of gamma radiation the CHLN does not present any protector action, neither promoter except in the litter I of the group

  1. Genetic consequences of radioactive contamination by the Chernobyl fallout to agricultural crops

    International Nuclear Information System (INIS)

    Geraskin, S.A.; Dikarev, V.G.; Zyablitskaya Ye.Ya.; Oudalova, A.A.; Spirin, Ye. V; Alexakhin, R.M.

    2003-01-01

    The genetic consequences of radioactive contamination by the fallout to agricultural crops after the accident at the Chernobyl NPP in 1986 have been studied. In the first, acute, period of this accident, when the absorbed dose was primarily due to external β- and γ-irradiation, the radiation injury of agricultural crops, according to the basic cytogenetic tests resembled the effect produced by acute γ-irradiation at comparable doses. The yield of cytogenetic damage in leaf meristem of plants grown in the 10-km zone of the ChNPP in 1987-1989 (the period of chronic, lower level radiation exposure) was shown to be enhanced and dependent on the level of radioactive contamination. The rate of decline with time in cytogenetic damage induced by chronic exposure lagged considerably behind that of the radiation exposure. Analysis of genetic variability in three sequentia generations of rye and wheat revealed increased cytogenetic damage in plants exposed to chronic irradiation during the 2nd and 3rd years

  2. The genetic effects of radio-activity in man and other organisms

    International Nuclear Information System (INIS)

    Parry, J.M.

    1979-01-01

    The changes that occur in the chromosomal information and which give rise to observable genetic effects stem from the induction by radiation of a number of lesions within the DNA. The relative frequencies of single and double strand breaks induced in DNA is dependent upon the type of radiation exposure given. Radiation sensitivity of a variety of different species of bacteria irradiated with gamma rays in air are given. The effect of dose rate upon radiation induced genetic damage indicates that at low dose rates the cells are capable of handling or repairing a higher proportion of the radiation induced DNA lesions before they undergo the events leading to chromosome and chromatid aberration. The radiation quality, expressed in terms of LET (linear energy transfer) also influence the induction of genetic damage. (U.K.)

  3. Cell immobilization by radiation polymerization-a comparative study

    International Nuclear Information System (INIS)

    Dahlan bin Hj Mohd; Abu Bakar bin Salleh; Che Nyonya binti Abd Razak; Meheran binti Hamenudin; Kamaruzaman bin Ampon; Wan Md Zin bin Wan Yunus; Mahiran binti Basri

    1991-01-01

    An extracellular lipase producing fungus, Rhizopus rhizopodi formis was immobilised using radiation-induced polyHEMA, alginate and k-carrageenan. Immobilizations were done on spores since they showed better resistance against gamma radiation. The simultaneous radiation immobilization technique was found to be unsuitable because of contamination. Post-radiation immobilization using polyHEMA yielded 2-3 times more enzyme than the free cells. The value, however was slightly lower than the ones given by the cells immobilised using alginate or k-carrageenan, but the radiation-induced polymer was stronger and less likely to disintegrate

  4. Inverse Estimation of Surface Radiation Properties Using Repulsive Particle Swarm Optimization Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyun Ho [Sejong University, Sejong (Korea, Republic of); Kim, Ki Wan [Agency for Defense Development, Daejeon (Korea, Republic of)

    2014-09-15

    The heat transfer mechanism for radiation is directly related to the emission of photons and electromagnetic waves. Depending on the participation of the medium, the radiation can be classified into two forms: surface and gas radiation. In the present study, unknown radiation properties were estimated using an inverse boundary analysis of surface radiation in an axisymmetric cylindrical enclosure. For efficiency, a repulsive particle swarm optimization (RPSO) algorithm, which is a relatively recent heuristic search method, was used as inverse solver. By comparing the convergence rates and accuracies with the results of a genetic algorithm (GA), the performances of the proposed RPSO algorithm as an inverse solver was verified when applied to the inverse analysis of the surface radiation problem.

  5. Inverse Estimation of Surface Radiation Properties Using Repulsive Particle Swarm Optimization Algorithm

    International Nuclear Information System (INIS)

    Lee, Kyun Ho; Kim, Ki Wan

    2014-01-01

    The heat transfer mechanism for radiation is directly related to the emission of photons and electromagnetic waves. Depending on the participation of the medium, the radiation can be classified into two forms: surface and gas radiation. In the present study, unknown radiation properties were estimated using an inverse boundary analysis of surface radiation in an axisymmetric cylindrical enclosure. For efficiency, a repulsive particle swarm optimization (RPSO) algorithm, which is a relatively recent heuristic search method, was used as inverse solver. By comparing the convergence rates and accuracies with the results of a genetic algorithm (GA), the performances of the proposed RPSO algorithm as an inverse solver was verified when applied to the inverse analysis of the surface radiation problem

  6. Is there a genetic instability in A-bomb survivors' lymphocytes?

    International Nuclear Information System (INIS)

    Nakamura, Nori; Kodama, Yoshiaki; Awa, Akio

    1997-01-01

    Based on the reports that the genetic instability can be induced even by low LET radiation and that the instability can be essentially the cause of radiation carcinogenicity, data accumulated hitherto on the chromosome aberrations in A-bomb survivors were re-evaluated since it can be conceivable that there is still remaining a genetic instability in them. For a measure of biological radiation dose, translocation frequency was used and for genetic instability, dicentrics frequency. The relationship between those frequencies was analyzed in about 2500 survivors and showed either a saturable or linear one. For clear conclusion, additional studies on dicentrics frequency occurring in cultured lymphocytes from subjects who received various radiation doses would be necessary. (K.H.)

  7. Genetic effects of radiation in man: a critical analysis of methodology with examples from three surveys among Brazilian physicians

    International Nuclear Information System (INIS)

    Freire-Maia, N.

    1978-01-01

    Information obtained through three different surveys (two via mail and one through personal interviews) made among Brazilian physicians in presented. Data have been classified according to survey, medical speciality, protection used and pregnancy order. Events under consideration are abortions, stillbirths, neo-natal mortality, infant-juvenile mortality (under two criteria) and sex ratio. A number of statistically significant diferences have been found in the direction expected according to the radio-genetics theory and a few ones against it. Two of the surveys reveal an effect of the pregnancy order an abortions which was larger in the exposed samples than in the control ones. This fact could be due to radiation-induced genetic damage, especially chromosome aberrations [pt

  8. Comparative Cost-Effectiveness of Stereotactic Body Radiation Therapy Versus Intensity-Modulated and Proton Radiation Therapy for Localized Prostate Cancer

    International Nuclear Information System (INIS)

    Parthan, Anju; Pruttivarasin, Narin; Davies, Diane; Taylor, Douglas C. A.; Pawar, Vivek; Bijlani, Akash; Lich, Kristen Hassmiller; Chen, Ronald C.

    2012-01-01

    Objective: To determine the cost-effectiveness of several external beam radiation treatment modalities for the treatment of patients with localized prostate cancer. Methods: A lifetime Markov model incorporated the probabilities of experiencing treatment-related long-term toxicity or death. Toxicity probabilities were derived from published sources using meta-analytical techniques. Utilities and costs in the model were obtained from publicly available secondary sources. The model calculated quality-adjusted life expectancy and expected lifetime cost per patient, and derived ratios of incremental cost per quality-adjusted life year (QALY) gained between treatments. Analyses were conducted from both payer and societal perspectives. One-way and probabilistic sensitivity analyses were performed. Results: Compared to intensity-modulated radiation therapy (IMRT) and proton beam therapy (PT), stereotactic body radiation therapy (SBRT) was less costly and resulted in more QALYs. Sensitivity analyses showed that the conclusions in the base-case scenario were robust with respect to variations in toxicity and cost parameters consistent with available evidence. At a threshold of $50,000/QALY, SBRT was cost-effective in 75% and 94% of probabilistic simulations compared to IMRT and PT, respectively, from a payer perspective. From a societal perspective, SBRT was cost-effective in 75% and 96% of simulations compared to IMRT and PT, respectively, at a threshold of $50,000/QALY. In threshold analyses, SBRT was less expensive with better outcomes compared to IMRT at toxicity rates 23% greater than the SBRT base-case rates. Conclusion: Based on the assumption that each treatment modality results in equivalent long-term efficacy, SBRT is a cost-effective strategy resulting in improved quality-adjusted survival compared to IMRT and PT for the treatment of localized prostate cancer.

  9. Comparative genomic analysis of Lactobacillus plantarum ZJ316 reveals its genetic adaptation and potential probiotic profiles.

    Science.gov (United States)

    Li, Ping; Li, Xuan; Gu, Qing; Lou, Xiu-Yu; Zhang, Xiao-Mei; Song, Da-Feng; Zhang, Chen

    2016-08-01

    In previous studies, Lactobacillus plantarum ZJ316 showed probiotic properties, such as antimicrobial activity against various pathogens and the capacity to significantly improve pig growth and pork quality. The purpose of this study was to reveal the genes potentially related to its genetic adaptation and probiotic profiles based on comparative genomic analysis. The genome sequence of L. plantarum ZJ316 was compared with those of eight L. plantarum strains deposited in GenBank. BLASTN, Mauve, and MUMmer programs were used for genome alignment and comparison. CRISPRFinder was applied for searching the clustered regularly interspaced short palindromic repeats (CRISPRs). We identified genes that encode proteins related to genetic adaptation and probiotic profiles, including carbohydrate transport and metabolism, proteolytic enzyme systems and amino acid biosynthesis, CRISPR adaptive immunity, stress responses, bile salt resistance, ability to adhere to the host intestinal wall, exopolysaccharide (EPS) biosynthesis, and bacteriocin biosynthesis. Comparative characterization of the L. plantarum ZJ316 genome provided the genetic basis for further elucidating the functional mechanisms of its probiotic properties. ZJ316 could be considered a potential probiotic candidate.

  10. Comparative genomic analysis of Lactobacillus plantarum ZJ316 reveals its genetic adaptation and potential probiotic profiles* #

    Science.gov (United States)

    Li, Ping; Li, Xuan; Gu, Qing; Lou, Xiu-yu; Zhang, Xiao-mei; Song, Da-feng; Zhang, Chen

    2016-01-01

    Objective: In previous studies, Lactobacillus plantarum ZJ316 showed probiotic properties, such as antimicrobial activity against various pathogens and the capacity to significantly improve pig growth and pork quality. The purpose of this study was to reveal the genes potentially related to its genetic adaptation and probiotic profiles based on comparative genomic analysis. Methods: The genome sequence of L. plantarum ZJ316 was compared with those of eight L. plantarum strains deposited in GenBank. BLASTN, Mauve, and MUMmer programs were used for genome alignment and comparison. CRISPRFinder was applied for searching the clustered regularly interspaced short palindromic repeats (CRISPRs). Results: We identified genes that encode proteins related to genetic adaptation and probiotic profiles, including carbohydrate transport and metabolism, proteolytic enzyme systems and amino acid biosynthesis, CRISPR adaptive immunity, stress responses, bile salt resistance, ability to adhere to the host intestinal wall, exopolysaccharide (EPS) biosynthesis, and bacteriocin biosynthesis. Conclusions: Comparative characterization of the L. plantarum ZJ316 genome provided the genetic basis for further elucidating the functional mechanisms of its probiotic properties. ZJ316 could be considered a potential probiotic candidate. PMID:27487802

  11. Ionizing radiations

    International Nuclear Information System (INIS)

    Newton, W.

    1984-01-01

    The purpose of this article is to simplify some of the relevant points of legislation, biological effects and protection for the benefit of the occupational health nurse not familiar with the nuclear industries. The subject is dealt with under the following headings; Understanding atoms. What is meant by ionizing radiation. Types of ionizing radiation. Effects of radiation: long and short term somatic effects, genetic effects. Control of radiation: occupational exposure, women of reproductive age, medical aspects, principles of control. The occupational health nurse's role. Emergency arrangements: national arrangements for incidents involving radiation, action to be taken by the nurse. Decontamination procedures: external and internal contamination. (U.K.)

  12. Genetic Variants in CD44 and MAT1A Confer Susceptibility to Acute Skin Reaction in Breast Cancer Patients Undergoing Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mumbrekar, Kamalesh Dattaram; Bola Sadashiva, Satish Rao [Department of Radiation Biology and Toxicology, School of Life Sciences, Manipal University, Manipal, Karnataka (India); Kabekkodu, Shama Prasada [Department of Biotechnology, School of Life Sciences, Manipal University, Manipal, Karnataka (India); Fernandes, Donald Jerard [Department of Radiotherapy and Oncology, Shirdi Saibaba Cancer Hospital and Research Centre, Kasturba Hospital, Manipal, Karnataka (India); Vadhiraja, Bejadi Manjunath [Department of Radiation Oncology, Manipal Hospital, Bengaluru, Karnataka (India); Suga, Tomo; Shoji, Yoshimi; Nakayama, Fumiaki; Imai, Takashi [Advanced Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Satyamoorthy, Kapaettu, E-mail: ksatyamoorthy@yahoo.com [Department of Biotechnology, School of Life Sciences, Manipal University, Manipal, Karnataka (India)

    2017-01-01

    Purpose: Heterogeneity in radiation therapy (RT)-induced normal tissue toxicity is observed in 10% of cancer patients, limiting the therapeutic outcomes. In addition to treatment-related factors, normal tissue adverse reactions also manifest from genetic alterations in distinct pathways majorly involving DNA damage–repair genes, inflammatory cytokine genes, cell cycle regulation, and antioxidant response. Therefore, the common sequence variants in these radioresponsive genes might modify the severity of normal tissue toxicity, and the identification of the same could have clinical relevance as a predictive biomarker. Methods and Materials: The present study was conducted in a cohort of patients with breast cancer to evaluate the possible associations between genetic variants in radioresponsive genes described previously and the risk of developing RT-induced acute skin adverse reactions. We tested 22 genetic variants reported in 18 genes (ie, NFE2L2, OGG1, NEIL3, RAD17, PTTG1, REV3L, ALAD, CD44, RAD9A, TGFβR3, MAD2L2, MAP3K7, MAT1A, RPS6KB2, ZNF830, SH3GL1, BAX, and XRCC1) using TaqMan assay-based real-time polymerase chain reaction. At the end of RT, the severity of skin damage was scored, and the subjects were dichotomized as nonoverresponders (Radiation Therapy Oncology Group grade <2) and overresponders (Radiation Therapy Oncology Group grade ≥2) for analysis. Results: Of the 22 single nucleotide polymorphisms studied, the rs8193 polymorphism lying in the micro-RNA binding site of 3′-UTR of CD44 was significantly (P=.0270) associated with RT-induced adverse skin reactions. Generalized multifactor dimensionality reduction analysis showed significant (P=.0107) gene–gene interactions between MAT1A and CD44. Furthermore, an increase in the total number of risk alleles was associated with increasing occurrence of overresponses (P=.0302). Conclusions: The genetic polymorphisms in radioresponsive genes act as genetic modifiers of acute normal tissue toxicity

  13. Radiation dose with digital breast tomosynthesis compared to digital mammography. Per-view analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gennaro, Gisella [Veneto Institute of Oncology IOV- IRCCS, Radiology Unit, Padua (Italy); Bernardi, D. [Azienda Provinciale Servizi Sanitari (APSS), U.O. Senologia Clinica e Screening Mammografico, Department of Diagnostics, Trento (Italy); Houssami, N. [University of Sydney, Screening and Test Evaluation Program (STEP), School of Public Health, Sydney Medical School, Sydney (Australia)

    2018-02-15

    To compare radiation dose delivered by digital mammography (FFDM) and breast tomosynthesis (DBT) for a single view. 4,780 FFDM and 4,798 DBT images from 1,208 women enrolled in a screening trial were used to ground dose comparison. Raw images were processed by an automatic software to determine volumetric breast density (VBD) and were used together with exposure data to compute the mean glandular dose (MGD) according to Dance's model. DBT and FFDM were compared in terms of operation of the automatic exposure control (AEC) and MGD level. Statistically significant differences were found between FFDM and DBT MGDs for all views (CC: MGD{sub FFDM}=1.366 mGy, MGD{sub DBT}=1.858 mGy; p<0.0001; MLO: MGD{sub FFDM}=1.374 mGy, MGD{sub DBT}=1.877 mGy; p<0.0001). Considering the 4,768 paired views, Bland-Altman analysis showed that the average increase of DBT dose compared to FFDM is 38 %, and a range between 0 % and 75 %. Our findings show a modest increase of radiation dose to the breast by tomosynthesis compared to FFDM. Given the emerging role of DBT, its use in conjunction with synthetic 2D images should not be deterred by concerns regarding radiation burden, and should draw on evidence of potential clinical benefit. (orig.)

  14. Chemical toxicity of uranium hexafluoride compared to acute effects of radiation

    International Nuclear Information System (INIS)

    McGuire, S.A.

    1991-02-01

    The chemical effects from acute exposures to uranium hexafluoride are compared to the nonstochastic effects from acute radiation doses of 25 rems to the whole body and 300 rems to the thyroid. The analysis concludes that an intake of about 10 mg of uranium in soluble form is roughly comparable, in terms of early effects, to an acute whole body dose of 25 rems because both are just below the threshold for significant nonstochastic effects. Similarly, an exposure to hydrogen fluoride at a concentration of 25 mg/m 3 for 30 minutes is roughly comparable because there would be no significant nonstochastic effects. For times t other than 30 minutes, the concentration C of hydrogen fluoride considered to have the same effect can be calculated using a quadratic equation: C = 25 mg/m 3 (30 min/t). The purpose of these analyses is to provide information for developing design and siting guideline based on chemical toxicity for enrichment plants using uranium hexafluoride. These guidelines are to be similar, in terms of stochastic health effects, to criteria in NRC regulations of nuclear power plants, which are based on radiation doses. 26 refs., 1 fig., 5 tabs

  15. Chemical toxicity of uranium hexafluoride compared to acute effects of radiation

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, S.A.

    1991-02-01

    The chemical effects from acute exposures to uranium hexafluoride are compared to the nonstochastic effects from acute radiation doses of 25 rems to the whole body and 300 rems to the thyroid. The analysis concludes that an intake of about 10 mg of uranium in soluble form is roughly comparable, in terms of early effects, to an acute whole body dose of 25 rems because both are just below the threshold for significant nonstochastic effects. Similarly, an exposure to hydrogen fluoride at a concentration of 25 mg/m{sup 3} for 30 minutes is roughly comparable because there would be no significant nonstochastic effects. For times t other than 30 minutes, the concentration C of hydrogen fluoride considered to have the same effect can be calculated using a quadratic equation: C = 25 mg/m{sup 3} (30 min/t). The purpose of these analyses is to provide information for developing design and siting guideline based on chemical toxicity for enrichment plants using uranium hexafluoride. These guidelines are to be similar, in terms of stochastic health effects, to criteria in NRC regulations of nuclear power plants, which are based on radiation doses. 26 refs., 1 fig., 5 tabs.

  16. Radiation and the evolution of life

    International Nuclear Information System (INIS)

    Gentner, N.E.; Myers, D.K.

    1980-08-01

    A general review is presented of the nature of various forms of radiation; radiant energy which reaches the earth from the sun; the role of this energy in prebiotic chemical evolution; current ideas on the origin of life; the dependence of living organisms upon radiant energy; the mechanisms responsible for the evolution of life, from the viewpoint of modern genetics and molecular biology; the biological consequences of alterations in the genetic material; and the role of ionizing radiation in production of genetic changes and in evolution. In the final analysis, the biosynthetic processes of life are driven by radiant energy from the sun. This overview is necessarily focussed on the infrared, visible and ultraviolet regions of the solar output spectrum since these particular radiations are responsible for most of the radiant energy that reaches the earth's surface. Ionizing radiation appears to have played at best a minor role in biological evolution. Small increments in the amounts of ionizing radiation are therefore unlikely to have a significant effect on life or its evolution. (auth)

  17. Radiation dose reduction: comparative assessment of publication volume between interventional and diagnostic radiology.

    Science.gov (United States)

    Hansmann, Jan; Henzler, Thomas; Gaba, Ron C; Morelli, John N

    2017-01-01

    We aimed to quantify and compare awareness regarding radiation dose reduction within the interventional radiology and diagnostic radiology communities. Abstracts accepted to the annual meetings of the Society of Interventional Radiology (SIR), the Cardiovascular and Interventional Radiological Society of Europe (CIRSE), the Radiological Society of North America (RSNA), and the European Congress of Radiology (ECR) between 2005 and 2015 were analyzed using the search terms "interventional/computed tomography" and "radiation dose/radiation dose reduction." A PubMed query using the above-mentioned search terms for the years of 2005-2015 was performed. Between 2005 and 2015, a total of 14 520 abstracts (mean, 660±297 abstracts) and 80 614 abstracts (mean, 3664±1025 abstracts) were presented at interventional and diagnostic radiology meetings, respectively. Significantly fewer abstracts related to radiation dose were presented at the interventional radiology meetings compared with the diagnostic radiology meetings (162 abstracts [1% of total] vs. 2706 [3% of total]; P radiology abstracts (range, 6-27) and 246±105 diagnostic radiology abstracts (range, 112-389) pertaining to radiation dose were presented at each meeting. The PubMed query revealed an average of 124±39 publications (range, 79-187) and 1205±307 publications (range, 829-1672) related to interventional and diagnostic radiology dose reduction per year, respectively (P radiology community over the past 10 years has not mirrored the increased volume seen within diagnostic radiology, suggesting that increased education and discussion about this topic may be warranted.

  18. Comparing targeted exome and whole exome approaches for genetic diagnosis of neuromuscular disorders

    Directory of Open Access Journals (Sweden)

    Svetlana Gorokhova

    2015-12-01

    Full Text Available Massively parallel sequencing is rapidly becoming a widely used method in genetic diagnostics. However, there is still no clear consensus as to which approach can most efficiently identify the pathogenic mutations carried by a given patient, while avoiding false negative and false positive results. We developed a targeted exome approach (MyoPanel2 in order to optimize genetic diagnosis of neuromuscular disorders. Using this approach, we were able to analyse 306 genes known to be mutated in myopathies as well as in related disorders, obtaining 98.8% target sequence coverage at 20×. Moreover, MyoPanel2 was able to detect 99.7% of 11,467 known mutations responsible for neuromuscular disorders. We have then used several quality control parameters to compare performance of the targeted exome approach with that of whole exome sequencing. The results of this pilot study of 140 DNA samples suggest that targeted exome sequencing approach is an efficient genetic diagnostic test for most neuromuscular diseases.

  19. Genetic effects of combined chemical-X-ray treatments in male mouse germ cells

    International Nuclear Information System (INIS)

    Cattanach, B.M.; Rasberry, C.

    1987-01-01

    Several studies have shown that the yield of genetic damage induced by radiation in male mouse germ cells can be modified by chemical treatments. Pre-treatments with radio-protecting agents have given contradictory results but this appears to be largely attributable to the different germ cell stages tested and dependent upon the level of radiation damage induced. Pre-treatments which enhance the yield of genetic damage have been reported although, as yet, no tests have been conducted with radio-sensitizers. Another form of interaction between chemicals and radiation is specifically found with spermatogonial stem cells. Chemicals that kill cells can, by population depletion, substantially and predictably modify the genetic response to subsequent radiation exposure over a period of several days, or even weeks. Enhancement and reduction in the genetic yield can be attained, dependent upon the interval between treatments, with the modification also varying with the type of genetic damage scored. Post-treatment with one chemical (TEM) has been shown to reduce the genetic response to radiation exposure. (author)

  20. Modification of genetic effect of gamma-irradiation by electric current

    International Nuclear Information System (INIS)

    Grigor'eva, N.N.; Shakhbazov, V.G.

    1983-01-01

    The effect of direct current of different polarity on genetic sequels of #betta#-radiation of Vicia faba seedlings is studied. It is established that weak current might modify genetic sequels of #betta#-radiation. Protective current effect on irradiated meristem cells of seedlings manifests at negative polarization of the meristem before radiation and at positive polarization-after radiation. Modifying effect of electric current is brought about at the expense of redistribution of anions and cations between the meristem and other root zones

  1. Radiation- induced aneuploidy in mammalian germ cells

    International Nuclear Information System (INIS)

    Tease, C.

    1989-01-01

    The ability of ionizing radiation to induce aneuploidy in mammalian germ cells has been investigated experimentally in the laboratory mouse using a variety of cytogenetic and genetic methods. These studies have provided unambiguous evidence of induced nondisjunction in both male and female germ cells when the effect of irradiation is screened in meiotic cells or preimplantation embryos. In contrast, however, cytogenetic analyses of post-implantation embryos and genetic assays for induced chromosome gains have not found a significant radiation effect. These apparently contradictory findings may be reconciled if (a) radiation induces tertiary rather than primary trisomy, or (b) induces embryo-lethal genetic damage, such as deletions, in addition to numerical anomalies. Either or both of these explanations may account for the apparent loss during gestation of radiation-induced trisomic embryos. Extrapolating from the information so far available, it seems unlikely that environmental exposure to low doses if low dose rate radiation will result in a detectable increase in the rate of aneuploidy in the human population. (author)

  2. Potential hazards of diagnostic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Houston, C S; Shokeir, M H

    1977-03-01

    There are no precise data for determining the extent of somatic damage from small doses of radiation used in diagnostic radiology. Diagnostic radiation given to pregnant women, knowingly or unknowingly, should rarely reach teratogenic levels causing brain and eye abnormalities. Evidence suggests that it does increase the risk of childhood malignancy, especially leukemia. Although rapidly growing tissues seem most susceptible, all radiation probably carries a very small risk of carcinogenesis. Genetic damage is equally difficult to estimate. Diagnostic radiation of females, even in childhood, may be related to an increased incidence of Down's syndrome in older mothers. Radiation also causes point mutations, which may explain the increase of some genetic abnormalities in progeny of older fathers. Whenever an abdominal or pelvic radiograph is ordered before the end of the reproductive period, there must be a potential benefit to balance the small risk involved.

  3. Lower radiation burden in state of the art fluoroscopic cystography compared to direct isotope cystography in children.

    Science.gov (United States)

    Haid, Bernhard; Becker, Tanja; Koen, Mark; Berger, Christoph; Langsteger, Werner; Gruy, Bernhard; Putz, Ernst; Haid, Stephanie; Oswald, Josef

    2015-02-01

    Both, fluoroscopic voiding cystourethrography (fVCUG) and direct isotope cystography (DIC) are diagnostic tools commonly used in pediatric urology. Both methods can detect vesicoureteral reflux (VUR) with a high sensitivity. Whilst the possibility to depict anatomical details and important structures as for instance the urethra in boys or the detailed calyceal anatomy are advantages of fVCUG, a lower radiation burden is thought to be the main advantage of DIC. In the last decade, however, a rapid technical evolution has occurred in fluoroscopy by implementing digital grid-controlled, variable rate, pulsed acquisition technique. As documented in literature this led to a substantial decrease in radiation burden conferred during fVCUGs. To question the common belief that direct isotope cystography confers less radiation burden compared to state of the art fluoroscopic voiding cystography. Radiation burden of direct isotope cystography in 92 children and in additional 7 children after an adaption of protocol was compared to radiation burden of fluoroscopic voiding cystourethrography in 51. The examinations were performed according to institutional protocols. For calculation of mean effective radiation dose [mSv] for either method published physical models correcting for age and sex were used. For DIC the model published by Stabin et al., 1998 was applied, for fVCUG two different physical models were used (Schultz et al., 1999, Lee et al., 2009). The radiation burden conferred by direct isotope cystography was significantly higher as for fluoroscopic voiding cystourethrography. The mean effective radiation dose for direct isotope cystography accounted to 0.23 mSv (± 0.34 m, median 0.085 mSv) compared to 0.015 mSv (± 0.013, median 0.008 mSv, model by Schultz et al.) - 0.024 mSv (± 0.018, median 0.018 mSv, model by Lee et al.) for fluoroscopic voiding cystourethrography. After a protocol adaption to correct for a longer examination time in DIC that was caused by

  4. Genetic effects of the atomic bombs: a reappraisal

    International Nuclear Information System (INIS)

    Schull, W.J.; Otake, M.; Neel, J.V.

    1981-01-01

    Data are presented on four indicators of genetic effects from studies of children born to survivors of the atomic bombings of Hiroshima and Nagasaki. The indicators are frequency of untoward pregnancy outcomes (stillbirth, major congenital defect, death during the first postnatal weak); occurrence of death in live-born children, through an average of life expectancy of 17 years; frequency of children with sex chromosome aneuploidy; and frequency of children with mutation resulting in an eletrophoretic variant. In no instance is there a statistically significant effect of parental exposure; but for all indicators the observed effect is in the direction suggested by the hypothesis that genetic damage resulted from the exposure. On the basis of assumptions concerning the contribution that spontaneous mutation in the preceding generation makes to the indicators in question, it is possible to estimate the genetic doubling dose for radiation for the first three indicators (the data base is still too small for the fourth). The average of these estimates is 156 rems. This is some four times higher than the results from experimental studies on the mouse with comparable radiation sources, which have been the principal guide to the presumed human sensitivities. The relevance of these data in setting permissible limits for human exposures is discussed briefly

  5. Genetic effects of the atomic bombs: a reappraisal

    International Nuclear Information System (INIS)

    Schull, W.J.; Otake, M.; Neel, J.V.

    1981-01-01

    Data are presented on four indicators of genetic effects from studies of children born to survivors of the atomic bombings of Hiroshima and Negasaki. The indicators are frequency of un toward pregnancy outcomes (stillbirth, major congenital defect, death during first postnatal week); occurrence of death in live-born children, through an average life expectancy of 17 years; frequency of children with sex chromosome aneuploidy; and frequency of children with mutation resulting in an electrophoretic variant. In no instance is there a statistically significant effect of parental exposure; but for all indicators the observed effect is in the direction suggested by the hypothesis that genetic damage resulted from the exposure. On the basis of assumptions concerning the contribution that spontaneous mutation in the preceding generation makes to the indicators in question, it is possible to estimate the genetic doubling dose for radiation for the first three indicators (the data base is still too small for the fourth). The average of these estimates is 156 rems. This is some four times higher than the results from experimental studies on the mouse with comparable radiation sources, which have been the principal guide to the presumed human sensitivities. The relevance of these data in setting permissible limits for human exposures is discussed briefly

  6. Conventional radiology and genetic dose

    International Nuclear Information System (INIS)

    Gonzalez-Vila, V.; Fernandez, A.; Rivera, F.; Martinez, M.; Gomez, A.; Luis, J.

    1992-01-01

    A research project was established in 1984 to evaluate the expected genetic abnormalities due to radiation received by the population attending the Outpatient Radiological Service due to medical radiological practices. The study was conducted in 1985 (12 weeks chosen by random). The equivalent gonadal dose was the chosen parameter, representing the social cost of the radiology. Samples of 2945 men and 2929 women were considered in the study. The number of genetic abnormalities, in relation to the mean age of reproduction (a generation every 30 years), was 2.13 cases per million in the first generation and 15.97 cases per million at equilibrium. The authors interpretation is that both the method and the expected genetic detriment are suitable procedures for the characterisation of the Radiological Service as a radiation source. (author)

  7. Comparative cost-effectiveness of stereotactic body radiation therapy versus intensity-modulated and proton radiation therapy for localized prostate cancer.

    Directory of Open Access Journals (Sweden)

    Anju eParthan

    2012-08-01

    Full Text Available Objective. To determine the cost-effectiveness of several external beam radiation treatment modalities for the treatment of patients with localized prostate cancer.Methods. A lifetime Markov model incorporated the probabilities of experiencing treatment-related long-term toxicity or death. Toxicity probabilities were derived from published sources using meta-analytical techniques. Utilities and costs in the model were obtained from publically available secondary sources. The model calculated quality-adjusted life expectancy and expected lifetime cost per patient, and derived ratios of incremental cost per quality-adjusted life year (QALY gained between treatments. Analyses were conducted from both a payer and societal perspectives. One-way and probabilistic sensitivity analyses were performed.Results. Compared to intensity modulated radiation therapy (IMRT and proton beam therapy (PT, stereotactic body radiation therapy (SBRT was less costly and resulted in more QALYs. Sensitivity analyses showed that the conclusions in the base-case scenario were robust with respect to variations in toxicity and cost parameters consistent with available evidence. At a threshold of $50,000/QALY, SBRT was cost effective in 75%, and 94% of probabilistic simulations compared to IMRT and PT, respectively, from a payer perspective. From a societal perspective, SBRT was cost-effective in 75%, and 96% of simulations compared to IMRT and PT, respectively, at a threshold of $50,000/QALY. In threshold analyses, SBRT was less expensive with better outcomes compared to IMRT at toxicity rates 23% greater than the SBRT base-case rates. Conclusions. Based on the assumption that each treatment modality results in equivalent long-term efficacy, SBRT is a cost-effective strategy resulting in improved quality-adjusted survival compared to IMRT and PT for the treatment of localized prostate cancer.

  8. Radiation protection for an intraoperative X-ray source compared to C-arm fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Frank; Clausen, Sven; Jahnke, Anika; Steil, Volker; Wenz, Frederik [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Radiation Oncology; Bludau, Frederic; Obertacke, Udo [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Trauma Surgery; Suetterlin, Marc [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Obstetrics and Gynaecology

    2014-10-01

    Background: Intraoperative radiotherapy (IORT) using the INTRABEAM {sup registered} system promises a flexible use regarding radiation protection compared to other approaches such as electron treatment or HDR brachytherapy with {sup 192}Ir or {sup 60}Co. In this study we compared dose rate measurements of breast- and Kypho-IORT with C-arm fluoroscopy which is needed to estimate radiation protection areas. Materials and Methods: C-arm fluoroscopy, breast- and Kypho-IORTs were performed using phantoms (silicon breast or bucket of water). Dose rates were measured at the phantom's surface, at 30 cm, 100 cm and 200 cm distance. Those measurements were confirmed during 10 Kypho-IORT and 10 breast-IORT patient treatments. Results: The measured dose rates were in the same magnitude for all three paradigms and ranges from 20 μSv/h during a simulated breast-IORT at two meter distance up to 64 mSv/h directly at the surface of a simulated Kypho-IORT. Those measurements result in a circle of controlled area (yearly doses > 6 mSv) for each paradigm of about 4 m ± 2 m. Discussion/Conclusions: All three paradigms show comparable dose rates which implies that the radiation protection is straight forward and confirms the flexible use of the INTRABEAM {sup registered} system. (orig.)

  9. Atom bombs and genetic damage

    International Nuclear Information System (INIS)

    Berry, R.J.

    1982-01-01

    Comments are made on a 1981 review on genetic damage in the off-spring of the atom bomb survivors in Hiroshima and Nagasaki. The main criticisms of the review concerned, 1) the 'minimal' doubling dose value for radiation-induced mutation in man, 2) the gametic doubling dose value for sex chromosome aneuploidy and 3) the validity of trebling an observed acute doubling dose to measure the effect of chronic irradiation. The firmest conclusion which may be deduced from the studies on A-bomb survivors is that humans are fairly resistant to genetic damage from radiation. (U.K.)

  10. Imaging Changes in Pediatric Intracranial Ependymoma Patients Treated With Proton Beam Radiation Therapy Compared to Intensity Modulated Radiation Therapy

    International Nuclear Information System (INIS)

    Gunther, Jillian R.; Sato, Mariko; Chintagumpala, Murali; Ketonen, Leena; Jones, Jeremy Y.; Allen, Pamela K.; Paulino, Arnold C.; Okcu, M. Fatih; Su, Jack M.; Weinberg, Jeffrey; Boehling, Nicholas S.; Khatua, Soumen; Adesina, Adekunle; Dauser, Robert; Whitehead, William E.; Mahajan, Anita

    2015-01-01

    Purpose: The clinical significance of magnetic resonance imaging (MRI) changes after radiation therapy (RT) in children with ependymoma is not well defined. We compared imaging changes following proton beam radiation therapy (PBRT) to those after photon-based intensity modulated RT (IMRT). Methods and Materials: Seventy-two patients with nonmetastatic intracranial ependymoma who received postoperative RT (37 PBRT, 35 IMRT) were analyzed retrospectively. MRI images were reviewed by 2 neuroradiologists. Results: Sixteen PBRT patients (43%) developed postradiation MRI changes at 3.8 months (median) with resolution by 6.1 months. Six IMRT patients (17%) developed changes at 5.3 months (median) with 8.3 months to resolution. Mean age at radiation was 4.4 and 6.9 years for PBRT and IMRT, respectively (P=.06). Age at diagnosis (>3 years) and time of radiation (≥3 years) was associated with fewer imaging changes on univariate analysis (odds ratio [OR]: 0.35, P=.048; OR: 0.36, P=.05). PBRT (compared to IMRT) was associated with more frequent imaging changes, both on univariate (OR: 3.68, P=.019) and multivariate (OR: 3.89, P=.024) analyses. Seven (3 IMRT, 4 PBRT) of 22 patients with changes had symptoms requiring intervention. Most patients were treated with steroids; some PBRT patients also received bevacizumab and hyperbaric oxygen therapy. None of the IMRT patients had lasting deficits, but 2 patients died from recurrent disease. Three PBRT patients had persistent neurological deficits, and 1 child died secondarily to complications from radiation necrosis. Conclusions: Postradiation MRI changes are more common with PBRT and in patients less than 3 years of age at diagnosis and treatment. It is difficult to predict causes for development of imaging changes that progress to clinical significance. These changes are usually self-limiting, but some require medical intervention, especially those involving the brainstem

  11. Estimation of the genetic risks of exposure to ionizing radiation in humans. Current status and emerging perspectives

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    2006-01-01

    The 2001 report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) on ''Hereditary effects of radiation'' incorporates two important concepts that have emerged from advances in radiation genetics and molecular biology: most radiation-induced mutations are DNA deletions, often encompassing multiple genes; however, because of structural and functional constraints, only a proportion of induced deletions may be compatible with viability and hence recoverable in the progeny and viability-compatible DNA deletions induced in human germ cells are more likely to cause multi-system developmental abnormalities rather than single-gene diseases. The work reported in this paper pursues these concepts further: it examines how mechanistic insights gained from studies of repair of radiation-induced DNA double-strand breaks (DSBs) in mammalian somatic cells and from those on the origin of deletions in human genomic disorders can be extended to germ cells the aim being the development of a framework to predict regions of the human genome that may be susceptible to radiation-induced deletions. A critical analysis of the available information permits the hypothesis that in stem cell spermatogonia, most induced deletions may arise via the non-homologous end joining (NHEJ) mechanism of DSB repair whereas in irradiated oocytes, the main mechanism is likely to be non-allelic homologous recombination (NAHR) between misaligned region-specific segmental duplications that are present in the genome (NAHR is an error-prone form of homologous recombination repair). Should this hypothesis turn out to be valid, then it is possible to build on the structural and functional aspects of genomic knowledge to devise strategies to predict where in the genome deletions may be induced by radiation, their extent and their potential phenotypes. (author)

  12. The enhancement of the nutritive value of mango seed kernel through radiation processing and other treatments

    International Nuclear Information System (INIS)

    Farag, M.D.E.

    1999-01-01

    The raw seed kernels of local mango (MSK) varieties (Magnifier indica L.)were analyzed for proximate composition, levels of trypsin inhibitor's, tannins, cyano genetic glucosides, in vitro protein digestibility and apparent metabolizable energy (AME n ) as being affected by boiling, autoclaving, autoclaving as well as radiation processing at doses 5, 10, and 20 KGy. The air-dry mango kernels were found to contain 70, 128, and 67 g kg - 1 of crude protein, crude fat and tannins, respectively. Compared with raw samples the contents of trypsin inhibitory activity (30 TIU g - 1) and cyano genetic glucosides, as hydrocyanic acid, (71 mg g kg - 1) were lowered by boiling, autoclaving and radiation treatments. Only boiling and autoclaving lowered tannins (67.2 g kg - 1) but radiation processing did not have any effect. The in vitro protein digestibility and AME n value by 139% and 72%, respectively. These results indicate that tannins, trypsin inhibitors and cyano genetic glucosides, are responsible for poor nutritive value of MSK

  13. Mutation frequencies in female mice and the estimation of genetic hazards of radiation in women

    International Nuclear Information System (INIS)

    Russell, W.L.

    1977-01-01

    The female germ cell stage of primary importance in radiation genetic hazards is the immature, arrested oocyte. In the mouse, this stage has a near zero or zero sensitivity to mutation induction by radiation. However, the application of these mouse results to women has been questioned on the ground that the mouse arrested oocytes are highly sensitive to killing by radiation, while the human cells are not; and, furthermore, that the mature and maturing oocytes in the mouse, which are resistant to killing, are sensitive to mutation induction. The present results have a 2-fold bearing on this problem. First, a more detailed analysis of oocyte-stage sensitivity to killing and mutation induction shows that there is no consistent correlation, either negative or positive, between the two. This indicates that the sensitivity to cell killing of the mouse immature oocyte may not be sufficient reason to prevent its use in predicting the mutational response of the human immature oocyte. Second, if the much more cautious assumption is made that the human arrested oocyte might be as mutationally sensitive as the most sensitive of all oocyte stages in the mouse, namely the maturing and mature ones, then the present data on the duration of these stages permit more accurate estimates than were heretofore possible on the mutational response of these stages to chronic irradiation

  14. Radiation-induced genomic instability, and the cloning and functional analysis of its related gene

    International Nuclear Information System (INIS)

    Muto, Masahiro; Kanari, Yasuyoshi; Kubo, Eiko; Yamada, Yutaka

    2000-01-01

    Exposure to ionizing radiation produces a number of biological consequences including gene mutations, chromosome aberrations, cellular transformation and cell death. The classical view has been that mutations occur at the sites of DNA damage, that is, damage produced by radiation is converted into a mutation during subsequent DNA replication or as a consequence of enzymatic repair processes. However, many investigators have presented evidence for an alternative mechanism to explain these biological effects. This evidence suggests that radiation may induce a process of genomic instability that is transmissible over many generations of cell replication and that serves to enhance the probability of the occurrence of such genetic effects among the progeny of the irradiated cell after many generations of cell replication. If such a process exists in vivo, it could have significant implications for mechanisms of carcinogenesis. Exposure of B10 mice to fractionated X-irradiation induces a high incidence of thymic lymphomas, whereas the incidence in STS/A mice is very low. Such strain differences are presumably determined genetically, and various genetic factors have been reported to be involved in radiation-induced lymphomagenesis. The mechanism of radiation-induced lymphomagenesis appears to develop through a complex and multistep process. Using this experimental system, we characterized the prelymphoma cells induced by radiation, and identified the genetic changes preceding the development of thymic lymphomas by comparing the oncogenic alterations with the pattern of T cell receptor (TCR) γ rearrangements. In these studies, the latent expression of some chromosomal aberrations and p53 mutations in irradiated progeny has been interpreted to be a manifestation of genomic instability. In the present report we review the results of in vivo studies conducted in our laboratory that support the hypothesis of genomic instability induced by radiation, and we describe the

  15. Assessment of risk from radiation sources

    International Nuclear Information System (INIS)

    Subbaratnam, T.; Madhvanath, U.; Somasundaram, S.

    1976-01-01

    Assessment of risk from exposure to ionizing radiations from man-made radiation sources and nuclear installations has to be viewed from three aspects, namely, dose-effect relationship (genetic and somatic) for humans, calculation of doses or dose-commitments to population groups, assessment of risk to radiation workers and the population at large from the current levels of exposure from nuclear industry and comparison of risk estimates with other industries in a modern society. These aspects are discussed in brief. On the basis of available data, it is shown that estimated incidence of genetic diseases and cancers due to exposure of population to radiation from nuclear industry is negligible in comparison with their natural incidence, and radiation risks to the workers in nuclear industry are much lower than the risks in other occupations. (M.G.B.)

  16. SNP in TXNRD2 Associated With Radiation-Induced Fibrosis: A Study of Genetic Variation in Reactive Oxygen Species Metabolism and Signaling

    International Nuclear Information System (INIS)

    Edvardsen, Hege; Landmark-Høyvik, Hege; Reinertsen, Kristin V.; Zhao, Xi; Grenaker-Alnæs, Grethe Irene; Nebdal, Daniel; Syvänen, Ann-Christine; Rødningen, Olaug; Alsner, Jan; Overgaard, Jens; Borresen-Dale, Anne-Lise; Fosså, Sophie D.; Kristensen, Vessela N.

    2013-01-01

    Purpose: The aim of the study was to identify noninvasive markers of treatment-induced side effects. Reactive oxygen species (ROS) are generated after irradiation, and genetic variation in genes related to ROS metabolism might influence the level of radiation-induced adverse effects (AEs). Methods and Materials: 92 breast cancer (BC) survivors previously treated with hypofractionated radiation therapy were assessed for the AEs subcutaneous atrophy and fibrosis, costal fractures, lung fibrosis, pleural thickening, and telangiectasias (median follow-up time 17.1 years). Single-nucleotide polymorphisms (SNPs) in 203 genes were analyzed for association to AE grade. SNPs associated with subcutaneous fibrosis were validated in an independent BC survivor material (n=283). The influence of the studied genetic variation on messenger ribonucleic acid (mRNA) expression level of 18 genes previously associated with fibrosis was assessed in fibroblast cell lines from BC patients. Results: Subcutaneous fibrosis and atrophy had the highest correlation (r=0.76) of all assessed AEs. The nonsynonymous SNP rs1139793 in TXNRD2 was associated with grade of subcutaneous fibrosis, the reference T-allele being more prevalent in the group experiencing severe levels of fibrosis. This was confirmed in another sample cohort of 283 BC survivors, and rs1139793 was found significantly associated with mRNA expression level of TXNRD2 in blood. Genetic variation in 24 ROS-related genes, including EGFR, CENPE, APEX1, and GSTP1, was associated with mRNA expression of 14 genes previously linked to fibrosis (P≤.005). Conclusion: Development of subcutaneous fibrosis can be associated with genetic variation in the mitochondrial enzyme TXNRD2, critically involved in removal of ROS, and maintenance of the intracellular redox balance

  17. Electrical Versus Optical: Comparing Methods for Detecting Terahertz Radiation Using Neon Lamps

    Science.gov (United States)

    Slocombe, L. L.; Lewis, R. A.

    2018-05-01

    Terahertz radiation impinging on a lit neon tube causes additional ionization of the encapsulated gas. As a result, the electrical current flowing between the electrodes increases and the glow discharge in the tube brightens. These dual phenomena suggest two distinct modes of terahertz sensing. The electrical mode simply involves measuring the electrical current. The optical mode involves monitoring the brightness of the weakly ionized plasma glow discharge. Here, we directly compare the two detection modes under identical experimental conditions. We measure 0.1-THz radiation modulated at frequencies in the range 0.1-10 kHz, for lamp currents in the range 1-10 mA. We find that electrical detection provides a superior signal-to-noise ratio while optical detection has a faster response. Either method serves as the basis of a compact, robust, and inexpensive room-temperature detector of terahertz radiation.

  18. Comparative transmission genetics of introgressed chromatin in Gossypium (cotton) polyploids.

    Science.gov (United States)

    Waghmare, Vijay N; Rong, Junkang; Rogers, Carl J; Bowers, John E; Chee, Peng W; Gannaway, John R; Katageri, Ishwarappa; Paterson, Andrew H

    2016-04-01

    Introgression is widely acknowledged as a potential source of valuable genetic variation, and growing effort is being invested in analysis of interspecific crosses conferring transgressive variation. Experimental backcross populations provide an opportunity to study transmission genetics following interspecific hybridization, identifying opportunities and constraints to introgressive crop improvement. The evolutionary consequences of introgression have been addressed at the theoretical level, however, issues related to levels and patterns of introgression among (plant) species remain inadequately explored, including such factors as polyploidization, subgenome interaction inhabiting a common nucleus, and the genomic distribution and linkage relationships of introgressant alleles. We analyze introgression into the polyploid Gossypium hirsutum (upland cotton) from its sister G. tomentosum and compare the level and pattern with that of G. barbadense representing a different clade tracing to the same polyploidization. Across the genome, recurrent backcrossing to Gossypium hirsutum yielded only one-third of the expected average frequency of the G. tomentosum allele, although one unusual region showed preferential introgression. Although a similar rate of introgression is found in the two subgenomes of polyploid (AtDt) G. hirsutum, a preponderance of multilocus interactions were largely within the Dt subgenome. Skewed G. tomentosum chromatin transmission is polymorphic among two elite G. hirsutum genotypes, which suggests that genetic background may profoundly affect introgression of particular chromosomal regions. Only limited correspondence is found between G. hirsutum chromosomal regions that are intolerant to introgression from the two species, G. barbadense and G. tomentosum, concentrated near possible inversion polymorphisms. Complex transmission of introgressed chromatin highlights the challenges to utilization of exotic germplasm in crop improvement. © 2016

  19. Comparative studies on sulfur, peroxide, and radiation vulcanization of EFDM rubber

    International Nuclear Information System (INIS)

    Abdel-Aziz, M.M.; Basfar, A.A.; Mofti, S.

    2000-01-01

    The temperature and concentration dependence of the vulcanization characteristics and mechanical properties of epdm rubber containing various concentrations of peroxide compounds was studied. The peroxides used are Luperox Di, Luperox 500-40 Ke, peroximon Dc Sc and peroximon Dc 40 Ke. The optimum cure parameters for the different types of peroxides indicated that Luperox Di, relatively, Give the best properties among the studied peroxides. The mechanical properties of EPDM containing different concentrations of Luperox Di and vulcanized at different temperatures were compared with those of either radiation or sulfur-cured EPDM. The modulus stress and tensile strength of the Luperox Di-cured EPDM were found to increase with either increasing the temperature of vulcanization and/ or concentration of the peroxide. Moreover, the tensile strength values are much higher than those of the sulfur-cured samples, except for those with low concentration of peroxide and vulcanized at relatively low temperature. A comparable result to those of the chemically vulcanized samples was attained by the radiation- vulcanized samples containing 1 phr of crosslinking agent and irradiated to 150 KGy

  20. Comparing of γ-ray, proton and neutron radiation effects on optoelectronics for space

    International Nuclear Information System (INIS)

    Yu Qingkui; Tang Min; Meng Meng; Li Pengwei; Wen Ping; Li Haian; Tang Jiesen; Wang Sixin; Song Yamei

    2014-01-01

    We performed irradiation test on optoelectronics with γ-rays, proton and neutron. The electrical measurements were performed pre and after irradiation. The degradations induced by each radiation source was compared. (authors)

  1. Regularities of radiation heredity

    International Nuclear Information System (INIS)

    Skakov, M.K.; Melikhov, V.D.

    2001-01-01

    One analyzed regularities of radiation heredity in metals and alloys. One made conclusion about thermodynamically irreversible changes in structure of materials under irradiation. One offers possible ways of heredity transmittance of radiation effects at high-temperature transformations in the materials. Phenomenon of radiation heredity may be turned to practical use to control structure of liquid metal and, respectively, structure of ingot via preliminary radiation treatment of charge. Concentration microheterogeneities in material defect structure induced by preliminary irradiation represent the genetic factor of radiation heredity [ru

  2. Germ cell toxicity: significance in genetic and fertility effects of radiation and chemicals

    International Nuclear Information System (INIS)

    Oakberg, E.F.

    1983-01-01

    The response of the male and female to radiation and chemicals is different. Any loss of oocytes in the female cannot be replaced, and if severe enough, will result in a shortening of the reproductive span. In the male, a temporary sterile period may be induced owing to destruction of the differentiating spermatogonia, but the stem cells are the most resistant spermatogonial type, are capable of repopulating the seminiferous epithelium, and fertility usually returns. The response of both the male and female changes with development of the embryonic to the adult gonad, and with differentiation and maturation in the adult. The primordial germ cells, early oocytes, and differentiating spermatogonia of the adult male are unusually sensitive to the cytotoxic action of noxious agents, but each agent elicits a specific response owing to the intricate biochemical and physiological changes associated with development and maturation of the gametes. The relationship of germ cell killing to fertility is direct, and long-term fertility effects can be predicted from histological analysis of the gonads. The relationship to genetic effects, on the other hand, is indirect, and acts primarily by limiting the cell stages available for testing, by affecting the distribution of mitotically active stem cells among the different stages of the mitotic cycle, and thereby, changing both the type and frequency of genetic effects observed. 100 references, 38 figures, 7 tables

  3. Biological indicators of radiation quality

    International Nuclear Information System (INIS)

    Bender, M.A.; Wong, R.M.A.

    1982-01-01

    The induction of many biological effects by high linear energy transfer (LET) radiation is strikingly different in one or two respects from the induction by acute low-LET radiation. If the acute low-LET dose-effect curve is of the usual quadratic form, it becomes linear as LET increases. In any case the linear slope increases as LET increases; that is, the relative biological effectiveness (RBE) increases. Both changes might be exploited as biological indicators of whether or not the recent recalculations of dose and of neutron contribution to dose at Hiroshima and Nagasaki seem consistent with the epidemiological observations. The biological end points that have been extensively studied in survivors include acute effects, growth and development after in utero or childhood exposure, genetic and cytogenetic effects in offspring, somatic chromosomal aberrations in survivors, and, of course, cancers, including leukemia. No significant indication among offspring of genetic or cytogenetic effects attributable to parental exposure has been found. Among the remaining end points, only the data on somatic chromosomal aberrations and on cancers appear robust enough to allow one to draw definite inferences by comparing experiences at the two cities

  4. 13th AINSE radiation biology conference: conference handbook

    International Nuclear Information System (INIS)

    1991-01-01

    The forty one papers presented at this conference covered the areas of radiation induced lesions, apoptosis, genetics and radiobiological consequences of low level radiation exposure, clinical applications of radiation, mammalian cells radiosensitivity and radiation-activated proteins

  5. Quantum-genetic theory of the hafure of malignant tumors

    International Nuclear Information System (INIS)

    Ovsyannikov, V.A.

    1984-01-01

    It is shown, that all interactions, which can cause a transformation in genetic code of a cell, from energy viewpoint should possess quantum energy from 4 to 10 eV, i.e. they should be referred to radiations of UV range. All the reasons known presently, which cause initial carcinomas, are accompanied by UV radiation in the range. The mechanism of UV radiation interaction with living cells, mechanism of genetic code transformation and mechanism of appearance and development of initial and secondary carcinomas are considered

  6. Genetic basis of resistance to trauma in inbred strains of mice

    International Nuclear Information System (INIS)

    Radojicic, C.; Andric, B.; Simovic, M.; Dujic, A.; Marinkovic, D.

    1990-01-01

    In this study the resistance to mechanical, thermal, and radiation trauma in four inbred strains of mice (AKR, BALB/c, CBA, and C57Bl/6) was compared with the degree of genetic resemblance, by analyzing the allozyme variabilities of these strains. It was shown that the highest degree of genetic resemblance was among CBA and AKR strains, which correlated with a similar degree of resistance to trauma. On the other hand, BALB/c and C57Bl/6 strains expressed significant differences, both genetically and with respect to the responses to trauma. The hypothesis is introduced that the genetic determination of the resistance to trauma is based on: (a) a polygenic control of general physiological homeostasis, with the possibility that (b) some specific genes or single loci may contribute more than others to such adaptations of the strains tested

  7. Radiation hazards and biological effects of ionising radiation on man

    International Nuclear Information System (INIS)

    Siti Najila Mohd Janib

    2004-01-01

    The contents of this chapter are follows - Mechanism of damage: direct action of radiation, indirect action of radiation. Classification of effects: somatic effect, induction of cancer, factors, affecting somatic effects, genetic effect, inherited abnormalities, induced effects, early effects, late effects, deterministic effect, stochastic effect. Effect of specific group: development abnormality, childhood Cancer, fertile women, risk and uncertainty, comparison of risk

  8. Impact of three genetic musculoskeletal diseases: a comparative synthesis of achondroplasia, Duchenne muscular dystrophy and osteogenesis imperfecta.

    Science.gov (United States)

    Dogba, Maman Joyce; Rauch, Frank; Douglas, Erin; Bedos, Christophe

    2014-10-25

    Achondroplasia, Duchenne muscular dystrophy, and osteogenesis imperfecta are among the most frequent rare genetic disorders affecting the musculoskeletal system in children. Rare genetic disorders are severely disabling and can have substantial impacts on families, children, and on healthcare systems. This literature review aims to classify, summarize and compare these non-medical impacts of achondroplasia, Duchenne muscular dystrophy and osteogenesis imperfecta.

  9. Genetic Characterization and Comparative Genome Analysis of Brucella melitensis Isolates from India

    Directory of Open Access Journals (Sweden)

    Sarwar Azam

    2016-01-01

    Full Text Available Brucellosis is the most frequent zoonotic disease worldwide, with over 500,000 new human infections every year. Brucella melitensis, the most virulent species in humans, primarily affects goats and the zoonotic transmission occurs by ingestion of unpasteurized milk products or through direct contact with fetal tissues. Brucellosis is endemic in India but no information is available on population structure and genetic diversity of Brucella spp. in India. We performed multilocus sequence typing of four B. melitensis strains isolated from naturally infected goats from India. For more detailed genetic characterization, we carried out whole genome sequencing and comparative genome analysis of one of the B. melitensis isolates, Bm IND1. Genome analysis identified 141 unique SNPs, 78 VNTRs, 51 Indels, and 2 putative prophage integrations in the Bm IND1 genome. Our data may help to develop improved epidemiological typing tools and efficient preventive strategies to control brucellosis.

  10. Construction of the first compendium of chemical-genetic profiles in the fission yeast Schizosaccharomyces pombe and comparative compendium approach

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sangjo [Bioinformatics Lab, Healthcare Group, SK Telecom, 9-1, Sunae-dong, Pundang-gu, Sungnam-si, Kyunggi-do 463-784 (Korea, Republic of); Lee, Minho [Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Chang, Hyeshik [Department of Biological Science, Seoul National University, 599 Gwanakro, Gwanak-gu, Seoul 151-747 (Korea, Republic of); Nam, Miyoung [Department of New Drug Discovery and Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764 (Korea, Republic of); Park, Han-Oh [Bioneer Corp., 8-11 Munpyeongseo-ro, Daedeok-gu, Daejeon 306-220 (Korea, Republic of); Kwak, Youn-Sig [Department of Applied Biology, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 660-701 (Korea, Republic of); Ha, Hye-jeong [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of); Kim, Dongsup [Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Hwang, Sung-Ook [Department of Obstetrics and Gynecology, Inha University Hospital, 7-206 Sinheung-dong, Jung-gu, Incheon 400-711 (Korea, Republic of); Hoe, Kwang-Lae [Department of New Drug Discovery and Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764 (Korea, Republic of); Kim, Dong-Uk [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of)

    2013-07-12

    Highlights: •The first compendium of chemical-genetic profiles form fission yeast was generated. •The first HTS of drug mode-of-action in fission yeast was performed. •The first comparative chemical genetic analysis between two yeasts was conducted. -- Abstract: Genome-wide chemical genetic profiles in Saccharomyces cerevisiae since the budding yeast deletion library construction have been successfully used to reveal unknown mode-of-actions of drugs. Here, we introduce comparative approach to infer drug target proteins more accurately using two compendiums of chemical-genetic profiles from the budding yeast S. cerevisiae and the fission yeast Schizosaccharomyces pombe. For the first time, we established DNA-chip based growth defect measurement of genome-wide deletion strains of S. pombe, and then applied 47 drugs to the pooled heterozygous deletion strains to generate chemical-genetic profiles in S. pombe. In our approach, putative drug targets were inferred from strains hypersensitive to given drugs by analyzing S. pombe and S. cerevisiae compendiums. Notably, many evidences in the literature revealed that the inferred target genes of fungicide and bactericide identified by such comparative approach are in fact the direct targets. Furthermore, by filtering out the genes with no essentiality, the multi-drug sensitivity genes, and the genes with less eukaryotic conservation, we created a set of drug target gene candidates that are expected to be directly affected by a given drug in human cells. Our study demonstrated that it is highly beneficial to construct the multiple compendiums of chemical genetic profiles using many different species. The fission yeast chemical-genetic compendium is available at (http://pombe.kaist.ac.kr/compendium)

  11. Solar radiation for buildings application: comparing reduced data set for mediterranean sites

    International Nuclear Information System (INIS)

    La Gennusa, M.; Rizzo, G.; Scaccianoce, G.; Sorrentino, G.

    2006-01-01

    A growing diffusion of computer programs for the thermal simulation of buildings is occurring in the last year; they allow the description of the thermal behaviour of buildings during the year, in order to verify their energy efficiencies and to suggest eventual improvements, even at the design stage. These thermal simulation programs generally need a complete input data set and among these, information particularly referring to the climatic conditions of the site where the building will be built-up. As it is well known, a climatic issue, particularly important for the thermal energy balance, is the solar radiation. In this work we have updated a short reference year of the solar radiation, more precisely the Monthly Average Day (MAD) for a town of the Southern Italy (Palermo), which shows climatic features similar to other places in the Mediterranean basin. In addition, we have compared the climatic data of the MAD (for the global and diffuse solar radiations) obtained from hourly measures for seven years, with those obtained both from geo-astronomical parameters and from the monthly average of the daily global solar radiation, which is commonly adopted on purposes. The comparison does suggest a particular caution in the choice of the method used for generating reduced data sets of the solar radiation for these mediterranean.(Author)

  12. Genetic influence of radiation measured by the effect on the mutation rate of human minisatellite genes

    International Nuclear Information System (INIS)

    Kodaira, Mieko

    2002-01-01

    Human minisatellite genes are composed from 0.1-30 kb with a high frequency of polymorphism. The genes exist in mammalian genomes and mice's ones are well studied after irradiation of their gonad cells by X-ray and γ-ray. Following five reports concerning the significant and/or insignificant increases of the mutation rate of the genes post A-bomb exposure, Chernobyl accident and nuclear weapons test in Semipalatinsk are reviewed and discussed on the subject number, exposed dose, problems of the control group, regions examined of loci and exposure conditions. Genetic influences of radiation examined by the author's facility are not recognized in the mutation rate (3.21% vs 4.94% in the control) of minisatellite genes in children of A-bomb survivors and their parents. The mutation rates are 4.27 vs 2.52% (positive influence) and 4.2-6.01% vs 3.5-6.34% in Chernobyl, and 4.3 (parents) and 3.8% (F 1 ) vs 2.5% (positive). Mutation of human minisatellite genes can be an important measure of genetic influences at the medical level. (K.H.)

  13. Perspectives in the paradigm of radiation-induced carcinogenesis

    International Nuclear Information System (INIS)

    Sugakhara, T.; Vatanabe, M.; Niva, O.; Nikajdo, O.

    1995-01-01

    Carcinogenesis is analysed as a multistage process consisting of initiation, promotion and progression. This model includes the mutation of oncogenes and the loss of hetrezygosity by tumor-suppressor genes. The threshold concept of radiation cancerogenesis is proposed, under which ionizing radiation can induce in somatic cell genetic effects a s result of DNA damage and epigenetic changes as well. The epigenetic changes (through DNA or cytoplasma) can be stabilized as mutations observed in many cancer cells and play a dominant role in radiation cancerogenesis induction. The ration of epigenetic and genetic effects largely depends on radiation doses

  14. Role-playing is an effective instructional strategy for genetic counseling training: an investigation and comparative study.

    Science.gov (United States)

    Xu, Xiao-Feng; Wang, Yan; Wang, Yan-Yan; Song, Ming; Xiao, Wen-Gang; Bai, Yun

    2016-09-02

    Genetic diseases represent a significant public health challenge in China that will need to be addressed by a correspondingly large number of professional genetic counselors. However, neither an official training program for genetic counseling, nor formal board certification, was available in China before 2015. In 2009, a genetic counseling training program based on role-playing was implemented as a pilot study at the Third Military Medical University to train third-year medical students. Questionnaires on participant attitudes to the program and role-playing were randomly administered to 324 students after they had finished their training. Pre- and post-training instructional tests, focusing on 42 key components of genetic counseling, were administered randomly to 200 participants to assess mastery of each component. Finally, scores in final examinations of 578 participants from 2009 to 2011 were compared to scores obtained by 614 non-participating students from 2006 to 2008 to further assess program efficacy. Both the training program and the instructional strategy of role-playing were accepted by most participants. Students believed that role-playing improved their practice of genetic counseling and medical genetics, enhanced their communication skills, and would likely contribute to future professional performance. The average understanding of 40 of the key points in genetic counseling was significantly improved, and most students approached excellent levels of mastery. Scores in final examinations and the percentages of students scoring above 90 were also significantly elevated. Role-playing is a feasible and effective instructional strategy for training genetic counselors in China as well as in other developing countries.

  15. Comparative transcriptome analysis of rice seedlings induced by different doses of heavy ion radiation

    Science.gov (United States)

    Zhao, Qian; Sun, Yeqing; Wang, Wei

    2016-07-01

    Highly ionizing radiation (HZE) in space is considered as a main factor causing biological effects on plant seeds. To investigate the different effects on genome-wide gene expression of low-dose and high-dose ion radiation, we carried out ground-base carbon particle HZE experiments with different cumulative doses (0Gy, 0.2Gy, 2Gy) to rice seeds and then performed comparative transcriptome analysis of the rice seedlings. We identified a total of 2551 and 1464 differentially expressed genes (DEGs) in low-dose and high-dose radiation groups, respectively. Gene ontology analyses indicated that low-dose and high-dose ion radiation both led to multiple physiological and biochemical activities changes in rice. By Gene Ontology analyses, the results showed that only one process-oxidation reduction process was enriched in the biological process category after high-dose ion radiation, while more processes such as response to biotic stimulus, heme binding, tetrapyrrole binding, oxidoreductase activity, catalytic activity and oxidoreductase activity were significantly enriched after low-dose ion radiation. The results indicated that the rice plants only focused on the process of oxidation reduction to response to high-dose ion radiation, whereas it was a coordination of multiple biological processes to response to low-dose ion radiation. To elucidate the transcriptional regulation of radiation stress-responsive genes, we identified several DEGs-encoding TFs. AP2/EREBP, bHLH, C2H2, MYB and WRKY TF families were altered significantly in response to ion radiation. Mapman analysis speculated that the biological effects on rice seedlings caused by the radiation stress might share similar mechanisms with the biotic stress. Our findings highlight important alterations in the expression of radiation response genes, metabolic pathways, and TF-encoding genes in rice seedlings exposed to low-dose and high-dose ion radiation.

  16. Radiation protection in veterinary medicine

    International Nuclear Information System (INIS)

    1991-01-01

    Diagnostic radiology is an essential part of present-day veterinary practice. The need for radiation protection exists because occupational exposure to ionizing radiation can result in deleterious effects that may manifest themselves not only in exposed individuals but in their descendants as well. These are respectively called somatic and genetic effects. Somatic effects are characterized by observable changes occurring in the body organs of the exposed individual. These changes may appear from within a few hours to many years later, depending on the amount and duration of exposure of the individual. In veterinary medicine, the possibility that anyone may be exposed to enough radiation to create somatic effect is extremely remote. Genetic effects are more a cause for concern at the lower doses used in veterinary radiology. Although the radiation doses may be small and appear to cause no observable damage, the probability of chromosomal damage in the germ cells, with the consequence of mutations, does exist. These mutations may give rise to genetic defects and therefore make these doses significant when applied to a large number of individuals. There are two main aspects of the problem to be considered. First, personnel working with X-ray equipment must be protected from excessive exposure to radiation during their work. Secondly, personnel in the vicinity of veterinary X-ray facilities and the general public require adequate protection

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

    International Nuclear Information System (INIS)

    Todorov, S.L.

    1979-01-01

    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)

  18. Nuclear radiation in warfare

    International Nuclear Information System (INIS)

    Rotblat, J.

    1986-01-01

    The subject is covered in chapters, entitled: introduction; digest of nuclear weaponry (characteristics of nuclear weapons; effects of nuclear weapons other than ionizing radiation (fire-ball, fall-out, thermal radiation, blast wave, electromagnetic pulse); the nuclear arms race; war scenarios; biological effects of radiations on man (radiation doses; natural sources of radiation; acute effects of radiation; long-term somatic effects; genetic effects; factors affecting the biological response to radiation; internal exposure; synergistic effects; protection against radiation effects); radiations from nuclear explosions (initial radiation; fall-out; effects of fall-out on animal and plant life; contamination of water and food supplies by fall-out); radiation casualties in a nuclear war; effectiveness of civil defence; other warlike uses of radiation (attacks on civilian nuclear power installations; radiological warfare; terrorist activities); conclusion. (orig./HP) [de

  19. Nuclear radiation in warfare

    International Nuclear Information System (INIS)

    Rotblat, J.

    1981-01-01

    The subject is covered in chapters, entitled: introduction; digest of nuclear weaponry (characteristics of nuclear weapons; effects of nuclear weapons other than ionizing radiation (fire-ball, fall-out, thermal radiation, blast wave, electromagnetic pulse); the nuclear arms race; war scenarios); biological effects of radiations on man (radiation doses; natural sources of radiation; acute effects of radiation; long-term somatic effects; genetic effects; factors affecting the biological response to radiation; internal exposure; synergistic effects; protection against radiation effects); radiations from nuclear explosions (initial radiation; fall-out; effects of fall-out on animal and plant life; contamination of water and food supplies by fall-out); radiation casualties in a nuclear war; effectiveness of civil defence; other warlike uses of radiation (attacks on civilian nuclear power installations; radiological warfare; terrorist activities); conclusion. (U.K.)

  20. 21 century perspective in radiation protection of humans and human population

    International Nuclear Information System (INIS)

    Vassilev, G.

    2003-01-01

    In 21 century ionizing radiation is applied in all field of human activities. In parallel, the radiobiology and radiation medicine are developing as separate branches for the purposes of the radiation protection: for risk estimation and regulation of the human irradiation. Main features of radiation protection at the beginning of the century are: 1.Well developed conservative theoretical background, based on the linear non-threshold concept 'dose-effect' towards the carcinogenesis and genetic effects; 2. Developed international and national structures, including organizations as ICRP, UNSCEAR, ICRU, IAEA, WHO, FAO, BEIR, OECD/NEA, ILO, NCRP, NRPB etc. 3. Detailed regulative legislation for all cases of human irradiation, combines with effective control structures. Ionizing radiation is the most strictly regulated factor affecting humans among the all adverse impacts of the living environment. The expectations for the radiation protection in 21 century are: 1. A radical reassessment of the concept for low doses and the linear non-threshold concept since data for existing of a threshold on the human population level. 2. Taking into consideration of the the adaptation to the irradiation, comparable with the natural radiation background. 3. Taking into consideration of the radiation hormesis, which are now ignored by the risk theory. 4. Clarification of the questions of the genetic effects, which are not yet determined for the human population. 5. Radical solutions of the radioactive waste problem, which will be crucial for the future of the nuclear energy production. 6. Gradual overcoming of the fear from ionizing radiation, which is an important social factor

  1. Ionizing radiation in environment

    International Nuclear Information System (INIS)

    Jandl, J.; Petr, I.

    1988-01-01

    The basic terms are explained such as the atom, radioactivity, nuclear reaction, interaction of ionizing radiation with matter, etc. The basic dosimetric variables and units and properties of radionuclides and ionizing radiation are given. Natural and artificial sources of ionizing radiation are discussed with regard to the environment and the propagation and migration of radionuclides is described in the environment to man. The impact is explained of ionizing radiation on the cell and the somatic and genetic effects of radiation on man are outlined. Attention is devoted to protection against ionizing radiation and to radiation limits, also to the detection, dosimetry and monitoring of ionizing radiation in the environment. (M.D.). 92 figs., 40 tabs. 74 refs

  2. Human genetics studies in areas of high natural radiation. V. regional and populational characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Freire-Maia, A [Faculdade de Ciencias Medicas e Biologicas de Botucatu (Brazil). Departamento de Genetica

    1974-12-01

    The region with high level of background radiation studied in our project is described. In the total, 8.572 couples and 43.930 pregnancy terminations were analyzed. The populational distribution of the 'relaive time of exposure to radiation' (coefficient R) is presented. The distributions of ethnic groups, alien ancestrals, mortality, morbidity, sex ratio, conditions of the household, instruction of the mother, and mean coefficients of inbreeding are also given, all the distributions are given comparatively for control and irradiated groups.

  3. Human genetics studies in areas of high natural radiation.V. regional and populational characteristics

    International Nuclear Information System (INIS)

    Freire-Maia, A.

    1974-01-01

    The region with high level of background radiation studied in our project is described. In the total, 8.572 couples and 43.930 pregnancy terminations were analyzed. The populational distribution of the 'relaive time of exposure to radiation' (coefficient R) is presented. The distributions of ethnic groups, alien ancestrals, mortality, morbidity, sex ratio, conditions of the household, instruction of the mother, and mean coefficients of inbreeding are also given, all the distributions are given comparatively for control and irradiated groups [pt

  4. Genetical analysis of the induced variation by gamma radiation in quantitative characters of Caupi [Vigna unguiculata (L.) Walp.

    International Nuclear Information System (INIS)

    Araujo, J.P.P. de.

    1987-10-01

    Genetical analysis procedures of the cobalt 60 gamma radiation effects in the induced mutations in quantitative characters of Caupi BR-1 Poty. The following characters were evaluated: day to first flower (FI), number of pods per plant (NVP), pod lenght (CMV), number of suds per pod (NSV), 100 seed wright (PCS), seed yield per plant (PSP) and seed yield per plant estimated by yield components (PSPE). The resistance of irradiated populations to cowpea aphid-borne mosaic virus (CpAMV)was also evaluated. (L.M.J.) [pt

  5. Genetics and developmental biology

    International Nuclear Information System (INIS)

    Barnett, W.E.

    1975-01-01

    Progress is reported on research activities in the fields of mutagenesis in Haemophilus influenzae and Escherichia coli; radioinduced chromosomal aberrations in mammalian germ cells; effects of uv radiation on xeroderma pigmentosum skin cells; mutations in Chinese hamster ovary cells; radioinduced hemoglobin variants in the mouse; analysis of mutants in yeast; Drosophila genetics; biochemical genetics of Neurospora; DNA polymerase activity in Xenopus laevis oocytes; uv-induced damage in Bacillus subtilis; and others

  6. Radiation-induced mutations and plant breeding

    International Nuclear Information System (INIS)

    Naqvi, S.H.M.

    1985-01-01

    Ionizing radiation could cause genetic changes in an organism and could modify gene linkages. The induction of mutation through radiation is random and the probability of getting the desired genetic change is low but can be increased by manipulating different parameters such as dose rate, physical conditions under which the material has been irradiated, etc. Induced mutations have been used as a supplement to conventional plant breeding, particularly for creating genetic variability for specific characters such as improved plant structure, pest and disease resistance, and desired changes in maturity period; more than 200 varieties of crop plants have been developed by this technique. The Pakistan Atomic Energy Commission has used this technique fruitfully to evolve better germplasm in cotton, rice, chickpea, wheat and mungbean; some of the mutants have become popular commercial varieties. This paper describes some uses of radiation induced mutations and the results achieved in Pakistan so far

  7. Genetic effects

    International Nuclear Information System (INIS)

    Bender, M.A.; Abrahamson, S.; Denniston, C.; Schull, W.J.

    1989-01-01

    In this chapter, we present a comprehensive analysis of the major classes of genetic diseases that would be increased as a result of an increased gonadal radiation exposure to a human population. The risk analysis takes on two major forms: the increase in genetic disease that would be observed in the immediate offspring of the exposed population, and the subsequent transmission of the newly induced mutations through future generations. The major classes of genetic disease will be induced at different frequencies, and will also impact differentially in terms of survivability and fertility on the affected individuals and their descendants. Some classes of disease will be expected to persist for only a few generations at most. Other types of genetic disease will persist through a longer period. The classes of genetic diseases studied are: dominant gene mutation, X-linked gene mutation, chromosome disorders and multifactorial disorders which involve the interaction of many mutant genes and environmental factors. For each of these classes we have derived the general equations of mutation induction for the male and female germ cells of critical importance in the mutation process. The frequency of induced mutations will be determined initially by the dose received, the type of radiation and, to some extent at high dose, by the manner in which the dose is received. We have used the modeling analyses to predict the outcomes for two nuclear power plant accident scenarios, the first in which the population receives a chronic dose of 0.1 Gy (10 rad) over a 50-year period, the second in which an equivalent population receives an acute dose of 2 Gy. In both cases the analyses are projected over a period of five generations

  8. Occupational exposure to radiation in the United Kingdom and its contribution to the genetically effective dose

    Energy Technology Data Exchange (ETDEWEB)

    Binks, W; Marley, W G

    1960-12-01

    It is now the common practice in the United Kingdom for persons who are exposed occupationally to ionizing radiations to be subjected to continuous individual monitoring in order to ensure that the doses that they receive from sources external to the body do not exceed the levels which are regarded as acceptable. In the operation of large-scale monitoring services such as are provided by the Radiological Protection Service (R.P.S.) and by the establishments of the United Kingdom Atomic Energy Authority (U.K.A.E.A.) there is no satisfactory alternative to the use of photographic film, bearing in mind such aspects as simplicity, reliability, accuracy, cheapness, ease of postal transmission of the films in the special holders, and availability of a durable record of the dose received. The Radiological Protection Service provides a film badge service which is widely used by industry. This organization also provides film badges for about one-third of the occupationally exposed persons in National Health Service hospitals; for the remaining hospital workers the majority of establishments undertake their own monitoring arrangements. The United Kingdom Atomic Energy Authority provides its own film badge services for all exposed workers. It is the purpose of this report to summarize the information obtained by the R.P.S. and the U.K.A.E.A. regarding the doses received by occupationally exposed persons. The total genetically effective dose received by the population from occupational exposure is also compared with that received from natural background radiation. This report also summarizes the measurements made by the R.P.S. and the U.K.A.E.A. to check the internal contamination of the body in cases where radioactivity has been ingested or inhaled.

  9. Occupational exposure to radiation in the United Kingdom and its contribution to the genetically effective dose

    International Nuclear Information System (INIS)

    Binks, W.; Marley, W.G.

    1960-01-01

    It is now the common practice in the United Kingdom for persons who are exposed occupationally to ionizing radiations to be subjected to continuous individual monitoring in order to ensure that the doses that they receive from sources external to the body do not exceed the levels which are regarded as acceptable. In the operation of large-scale monitoring services such as are provided by the Radiological Protection Service (R.P.S.) and by the establishments of the United Kingdom Atomic Energy Authority (U.K.A.E.A.) there is no satisfactory alternative to the use of photographic film, bearing in mind such aspects as simplicity, reliability, accuracy, cheapness, ease of postal transmission of the films in the special holders, and availability of a durable record of the dose received. The Radiological Protection Service provides a film badge service which is widely used by industry. This organization also provides film badges for about one-third of the occupationally exposed persons in National Health Service hospitals; for the remaining hospital workers the majority of establishments undertake their own monitoring arrangements. The United Kingdom Atomic Energy Authority provides its own film badge services for all exposed workers. It is the purpose of this report to summarize the information obtained by the R.P.S. and the U.K.A.E.A. regarding the doses received by occupationally exposed persons. The total genetically effective dose received by the population from occupational exposure is also compared with that received from natural background radiation. This report also summarizes the measurements made by the R.P.S. and the U.K.A.E.A. to check the internal contamination of the body in cases where radioactivity has been ingested or inhaled

  10. Importance of plants in radiation protection

    International Nuclear Information System (INIS)

    Rawat, Shalini

    2015-01-01

    Radioactive substances from nuclear programme structures are one of the major toxicant causing serious health hazards. These manmade radiations include X-ray machines radioactive fall-outs, nuclear reactor waste, TV, computers etc. Effect of radiation may be somatic and genetic. Most genetic effects are brought by manmade radiations. Plants on one hand using the electromagnetic radiation from sun for one of the most important vital activity of earth called Photosynthesis and on the other hand protecting us from harmful radiations. There are however, many natural compounds with radio-protective activity. Such compounds include sulfhydryl-containing compounds and anti-oxidant nutrients such as vitamins C and E, beta-carotene, N-acetylcysteine and selenium, along with a range of phytochemicals found in plants such as Ginkgo biloba, Vitis vinifera (Grape), Ocimum sanctum (Tulsi or holy basil). Some plants have capacity to absorb harmful radiation of computers like Aloe, Cactus, etc. Such study can be helpful in minimizing radiation pollution. Present review paper emphasizing Botanical, Ecological and Economic aspects of some plants. (author)

  11. Comparative linkage meta-analysis reveals regionally-distinct, disparate genetic architectures: application to bipolar disorder and schizophrenia.

    Directory of Open Access Journals (Sweden)

    Brady Tang

    2011-04-01

    Full Text Available New high-throughput, population-based methods and next-generation sequencing capabilities hold great promise in the quest for common and rare variant discovery and in the search for "missing heritability." However, the optimal analytic strategies for approaching such data are still actively debated, representing the latest rate-limiting step in genetic progress. Since it is likely a majority of common variants of modest effect have been identified through the application of tagSNP-based microarray platforms (i.e., GWAS, alternative approaches robust to detection of low-frequency (1-5% MAF and rare (<1% variants are of great importance. Of direct relevance, we have available an accumulated wealth of linkage data collected through traditional genetic methods over several decades, the full value of which has not been exhausted. To that end, we compare results from two different linkage meta-analysis methods--GSMA and MSP--applied to the same set of 13 bipolar disorder and 16 schizophrenia GWLS datasets. Interestingly, we find that the two methods implicate distinct, largely non-overlapping, genomic regions. Furthermore, based on the statistical methods themselves and our contextualization of these results within the larger genetic literatures, our findings suggest, for each disorder, distinct genetic architectures may reside within disparate genomic regions. Thus, comparative linkage meta-analysis (CLMA may be used to optimize low-frequency and rare variant discovery in the modern genomic era.

  12. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Heribanova, A.

    1995-01-01

    The basic principles and pathways of effects of ionizing radiation on living organisms and cells are outlined. The following topics are covered: effects of radiation on living matter (direct effects, radical or indirect effects, dual radiation action, and molecular biological theories); effects of radiation on cells and tissues (cell depletion, changes in the cytogenetic information, reparation mechanisms), dose-response relationship (deterministic effects, stochastic effects), and the effects of radiation on man (acute radiation sickness, acute local changes, fetus injuries, non-tumorous late injuries, malignant tumors, genetic changes). (P.A.). 3 tabs., 2 figs., 5 refs

  13. Exposure to low-dose radiation and the risk of breast cancer among women with a familial or genetic predisposition: a meta-analysis

    International Nuclear Information System (INIS)

    Jansen-van der Weide, Marijke C.; Greuter, Marcel J.W.; Pijnappel, Ruud M.; Jansen, Liesbeth; Oosterwijk, Jan C.; Bock, Geertruida H. de

    2010-01-01

    Women with familial or genetic aggregation of breast cancer are offered screening outside the population screening programme. However, the possible benefit of mammography screening could be reduced due to the risk of radiation-induced tumours. A systematic search was conducted addressing the question of how low-dose radiation exposure affects breast cancer risk among high-risk women. A systematic search was conducted for articles addressing breast cancer, mammography screening, radiation and high-risk women. Effects of low-dose radiation on breast cancer risk were presented in terms of pooled odds ratios (OR). Of 127 articles found, 7 were selected for the meta-analysis. Pooled OR revealed an increased risk of breast cancer among high-risk women due to low-dose radiation exposure (OR = 1.3, 95% CI: 0.9- 1.8). Exposure before age 20 (OR = 2.0, 95% CI: 1.3-3.1) or a mean of ≥5 exposures (OR = 1.8, 95% CI: 1.1-3.0) was significantly associated with a higher radiation-induced breast cancer risk. Low-dose radiation increases breast cancer risk among high-risk women. When using low-dose radiation among high-risk women, a careful approach is needed, by means of reducing repeated exposure, avoidance of exposure at a younger age and using non-ionising screening techniques. (orig.)

  14. Genetic sex determination in Astatotilapia calliptera, a prototype species for the Lake Malawi cichlid radiation

    Science.gov (United States)

    Peterson, Erin N.; Cline, Maggie E.; Moore, Emily C.; Roberts, Natalie B.; Roberts, Reade B.

    2017-06-01

    East African cichlids display extensive variation in sex determination systems. The species Astatotilapia calliptera is one of the few cichlids that reside both in Lake Malawi and in surrounding waterways. A. calliptera is of interest in evolutionary studies as a putative immediate outgroup species for the Lake Malawi species flock and possibly as a prototype ancestor-like species for the radiation. Here, we use linkage mapping to test association of sex in A. calliptera with loci that have been previously associated with genetic sex determination in East African cichlid species. We identify a male heterogametic XY system segregating at linkage group (LG) 7 in an A. calliptera line that originated from Lake Malawi, at a locus previously shown to act as an XY sex determination system in multiple species of Lake Malawi cichlids. Significant association of genetic markers and sex produce a broad genetic interval of approximately 26 megabases (Mb) using the Nile tilapia genome to orient markers; however, we note that the marker with the strongest association with sex is near a gene that acts as a master sex determiner in other fish species. We demonstrate that alleles of the marker are perfectly associated with sex in Metriaclima mbenjii, a species from the rock-dwelling clade of Lake Malawi. While we do not rule out the possibility of other sex determination loci in A. calliptera, this study provides a foundation for fine mapping of the cichlid sex determination gene on LG7 and evolutionary context regarding the origin and persistence of the LG7 XY across diverse, rapidly evolving lineages.

  15. Genetic algorithms - A new technique for solving the neutron spectrum unfolding problem

    International Nuclear Information System (INIS)

    Freeman, David W.; Edwards, D. Ray; Bolon, Albert E.

    1999-01-01

    A new technique utilizing genetic algorithms has been applied to the Bonner sphere neutron spectrum unfolding problem. Genetic algorithms are part of a relatively new field of 'evolutionary' solution techniques that mimic living systems with computer-simulated 'chromosome' solutions. Solutions mate and mutate to create better solutions. Several benchmark problems, considered representative of radiation protection environments, have been evaluated using the newly developed UMRGA code which implements the genetic algorithm unfolding technique. The results are compared with results from other well-established unfolding codes. The genetic algorithm technique works remarkably well and produces solutions with relatively high spectral qualities. UMRGA appears to be a superior technique in the absence of a priori data - it does not rely on 'lucky' guesses of input spectra. Calculated personnel doses associated with the unfolded spectra match benchmark values within a few percent

  16. Non controlled effect of ionizing radiations : involvement for radiation protection

    International Nuclear Information System (INIS)

    Little, J. B.

    2005-01-01

    It is widely accepted that damage to DNA is the critical event on irradiated cells, and that double strand breaks are the primary DNA lesions responsible for the biological effects of ionizing radiation. This has lead to the long standing paradigm that these effects, be they cytotoxicity, mutagenesis or malignant transformation, occur in irradiated cells as a consequences of the DNA damage they incur. Evidence has been accumulating over the past decade, however, to indicate that radiation may induce effects that ar not targeted to the irradiated cells itself. Two non-targeted effects will be described in this review. The first, radiation-induced genomic instability, is a phenomenon whereby signals are transmitted to the progeny of the irradiated cell over many generations, leading to the occurrence of genetic effects such as mutations and chromosomal aberrations arising in the distant descendants of the irradiated cell. Second, the bystander effect, is a phenomenon whereby irradiated cells transmit damage signals to non-irradiated cells in a mixed population, leading to genetic effects arising in these bystander cells that received no radiation exposure. the model system described in this review involves dense monolayer cultures exposed to very low fluences of alpha particles. The potential implications of these two phenomena for the analysis of the risk to the human population of exposure to low levels of ionising radiation is discussed. (Author) 111 refs

  17. Multiplex Polymerase Chain Reaction for Identification of Shigellae and Four Shigella Species Using Novel Genetic Markers Screened by Comparative Genomics.

    Science.gov (United States)

    Kim, Hyun-Joong; Ryu, Ji-Oh; Song, Ji-Yeon; Kim, Hae-Yeong

    2017-07-01

    In the detection of Shigella species using molecular biological methods, previously known genetic markers for Shigella species were not sufficient to discriminate between Shigella species and diarrheagenic Escherichia coli. The purposes of this study were to screen for genetic markers of the Shigella genus and four Shigella species through comparative genomics and develop a multiplex polymerase chain reaction (PCR) for the detection of shigellae and Shigella species. A total of seven genomic DNA sequences from Shigella species were subjected to comparative genomics for the screening of genetic markers of shigellae and each Shigella species. The primer sets were designed from the screened genetic markers and evaluated using PCR with genomic DNAs from Shigella and other bacterial strains in Enterobacteriaceae. A novel Shigella quintuplex PCR, designed for the detection of Shigella genus, S. dysenteriae, S. boydii, S. flexneri, and S. sonnei, was developed from the evaluated primer sets, and its performance was demonstrated with specifically amplified results from each Shigella species. This Shigella multiplex PCR is the first to be reported with novel genetic markers developed through comparative genomics and may be a useful tool for the accurate detection of the Shigella genus and species from closely related bacteria in clinical microbiology and food safety.

  18. Epigenetic mechanism of radiation carcinogenesis

    International Nuclear Information System (INIS)

    Niwa, Ohtsura

    1995-01-01

    Carcinogenic action of radiations has long been thought to be due to its mutagenic activity. Since DNA damage is induced and distributes in a stochastic fashion, radiation induction of cancers was also assumed to follow a stochastic kinetics. However, recent progress in radiation research has revealed that some features of radiation carcinogenesis are not explainable by the simple action of radiation as a DNA damaging and mutagenic agent. Firstly, frequencies of radiation-induced transformation in vitro and radiation-induced mammary cancers in rats are too high to be accounted for by the frequency of radiation-induced mutation. Secondly, trans-generation carcinogenesis among F1 mice born to irradiated parents occurs also much more frequently than to be predicted by the frequency of radiation induced germline mutation. Thirdly, multistage carcinogenesis theory predicts that carcinogens give hits to the target cells so as to shorten the latency of cancers. However, latencies of radiation induced solid cancers among atomic bomb survivors are similar to those of the control population. Fourthly, although radiation elevates the frequency of cancers, the induced cancers seem to share the same spectrum of cancer types as in the unirradiated control populations. This suggests that radiation induces cancer by enhancement of the spontaneous carcinogenesis process. These data suggest that the first step of radiation carcinogenesis may not be the direct induction of mutation. Radiation may induce genetic instability which increases the spontaneous mutation rate in the cells to produce carcinogenic mutations. Growth stimulatory effect of radiation may also contribute to the process. Thus, epigenetic, but not genetic effect of radiation might better contribute in the process of carcinogenesis. (author)

  19. Down's syndrome and related abnormalities in an area of high background radiation in coastal Kerala

    International Nuclear Information System (INIS)

    Kochupillai, N.; Verma, I.C.; Grewal, M.S.; Ramalingaswami, V.

    1976-01-01

    It is stated that in a coastal area of Kerala, Southern India, the background radiation is between 1500 and 3000 mR/yr, this being due to the presence of Th-containing monazite mineral in the soil. During an epidemiological study of modular lesions of the thyroid in this area an apparently high prevalence of Down's syndrome and other forms of severe mental retardation was observed. A house-to-house survey of relevant abnormalities in this area was made, and also in a comparable control area without high background radiation. The frequency of chromosome aberrations in a sample of the population in the study and control areas was also investigated. The observations support the view that radiation induces genetic anomalies occur with above average frequency in the population living in the area with high background radiation. Only gross abnormalities evident in clinical examination were recorded. The study and control populations were similar in age and sex structure and general sociologic conditions. Severe mental retardation was the commonest abnormality encountered, and 85% of the abnormalities detected in the study population were genetic in origin, compared with 56% in the control population. Prevalence of Down's syndrome was 0.93 per 1000 in the study population. (U.K.)

  20. Carcinogenesis. Genetics and circumstances

    International Nuclear Information System (INIS)

    Hino, Okio

    2005-01-01

    Described are the author's study and aspect concerning carcinogenesis and radiation carcinogenesis, where he thinks cancer is not automatic, has a process and takes time. For radiation carcinogenic studies, he has used a model of the rat with genetically determined kidney cancer which is highly radiosensitive. That is, mutation by the so-called 2nd-hit of the causal gene (tumor suppressing gene Tsc2) is studied in the animal where the 1st-hit has been done by retrotransposon insertion, with and without exposure to radiations (X-ray, heavy particle beam and cosmic ray) for elucidating the mutation spectrum of the causal gene, the carcinogenic target, for the ultimate aim to prevent human cancer. He discusses the drama-type molecular mechanisms leading to cancer, gene abnormality and disease crisis, discontinuity in continuity in cancer formation, and importance of the timely diagnosis and appropriate therapy, and concludes the present age is becoming such one as that the nature of cancer even if genetic can be controlled by circumstances like timely and appropriate intervention. (S.I.)

  1. A comparative analysis of exposure doses between the radiation workers in dental and general hospital

    International Nuclear Information System (INIS)

    Yang, Nam Hee; Chung, Woon Kwan; Dong, Kyung Rae; Ju, Yong Jin; Song, Ha Jin; Choi, Eun Jin

    2015-01-01

    Research and investigation is required for the exposure dose of radiation workers to work in the dental hospital as increasing interest in exposure dose of the dental hospital recently accordingly, study aim to minimize radiation exposure by making a follow-up study of individual exposure doses of radiation workers, analyzing the status on individual radiation exposure management, prediction the radiation disability risk levels by radiation, and alerting the workers to the danger of radiation exposure. Especially given the changes in the dental hospital radiation safety awareness conducted the study in order to minimize radiation exposure. This study performed analyses by a comparison between general and dental hospital, comparing each occupation, with the 116,220 exposure dose data by quarter and year of 5,811 subjects at general and dental hospital across South Korea from January 1, 2008 through December 31, 2012. The following are the results obtained by analyzing average values year and quarter. In term of hospital, average doses were significantly higher in general hospitals than detal ones. In terms of job, average doses were higher in radiological technologists the other workers. Especially, they showed statistically significant differences between radiological technologists than dentists. The above-mentioned results indicate that radiation workers were exposed to radiation for the past 5 years to the extent not exceeding the dose limit (maximum 50 mSv y -1 ). The limitation of this study is that radiation workers before 2008 were excluded from the study. Objective evaluation standards did not apply to the work circumstance or condition of each hospital. Therefore, it is deemed necessary to work out analysis criteria that will be used as objective evaluation standard. It will be necessary to study radiation exposure in more precise ways on the basis of objective analysis standard in the future. Should try to minimize the radiation individual dose of

  2. A comparative analysis of exposure doses between the radiation workers in dental and general hospital

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Nam Hee; Chung, Woon Kwan; Dong, Kyung Rae; Ju, Yong Jin; Song, Ha Jin [Dept. of Nuclear Engineering, Chosun University, Gwangju (Korea, Republic of); Choi, Eun Jin [Dept. of Public Health and Medicine, Dongshin University, Naju (Korea, Republic of)

    2015-02-15

    Research and investigation is required for the exposure dose of radiation workers to work in the dental hospital as increasing interest in exposure dose of the dental hospital recently accordingly, study aim to minimize radiation exposure by making a follow-up study of individual exposure doses of radiation workers, analyzing the status on individual radiation exposure management, prediction the radiation disability risk levels by radiation, and alerting the workers to the danger of radiation exposure. Especially given the changes in the dental hospital radiation safety awareness conducted the study in order to minimize radiation exposure. This study performed analyses by a comparison between general and dental hospital, comparing each occupation, with the 116,220 exposure dose data by quarter and year of 5,811 subjects at general and dental hospital across South Korea from January 1, 2008 through December 31, 2012. The following are the results obtained by analyzing average values year and quarter. In term of hospital, average doses were significantly higher in general hospitals than detal ones. In terms of job, average doses were higher in radiological technologists the other workers. Especially, they showed statistically significant differences between radiological technologists than dentists. The above-mentioned results indicate that radiation workers were exposed to radiation for the past 5 years to the extent not exceeding the dose limit (maximum 50 mSv y{sup -1}). The limitation of this study is that radiation workers before 2008 were excluded from the study. Objective evaluation standards did not apply to the work circumstance or condition of each hospital. Therefore, it is deemed necessary to work out analysis criteria that will be used as objective evaluation standard. It will be necessary to study radiation exposure in more precise ways on the basis of objective analysis standard in the future. Should try to minimize the radiation individual dose of

  3. Radiation mutagenesis in development of genetic fundamentals of cotton selection

    International Nuclear Information System (INIS)

    Musaev, D.A.; Almatov, A.S.

    1987-01-01

    Some results of investigations on preparation and genetic analysis of mutants in inbreeding lines of genetic collections of cotton plants, as well as problems on mutant application in practical selection are covered. The results show that the scientific authenticity and efficiency of fundamental and applied investigations in the field of experimental mutagenesis of cotton plants,being a facultative self-polinator, depend on keeping necessary methodical requirements. Application of inbreeding lines of genetic collection with marker features as the initial material, isolation of plants usinng self-polination of flowers on all stages of investigation are related to these requirements. Several methodical recommendations on genetic-selective investigations are developed

  4. Research of radiation-resistant microbial organisms

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongho; Lim, Sangyong; Joe, Minho; Park, Haejoon; Song, Hyunpa; Im, Seunghun; Kim, Haram; Kim, Whajung; Choi, Jinsu; Park, Jongchun

    2012-01-15

    Many extremophiles including radiation-resistant bacteria Deinococcus radiodurans have special characteristics such as novel enzymes and physiological active substances different from known biological materials and are being in the spotlight of biotechnology science. In this research, basic technologies for the production of new genetic resources and microbial strains by a series of studies in radiation-resistant microbial organisms were investigated and developed. Mechanisms required for radiation-resistant in Deinococcus radiodurans were partly defined by analyzing the function of dinB, pprI, recG, DRA{sub 0}279, pprM, and two-component signal transduction systems. To apply genetic resource and functional materials from Deinococcus species, omics analysis in response to cadmium, construction of macroscopic biosensor, and characterization of carotenoids and chaperon protein were performed. Additionally, potential use of D. geothermalis in monosaccharide production from non-biodegradable plant materials was evaluated. Novel radiation resistant yeasts and bacteria were isolated and identified from environmental samples to obtain microbial and genomic resources. An optimal radiation mutant breeding method was set up for efficient and rapid isolation of target microbial mutants. Furthermore, an efficient ethanol producing mutant strain with high production yield and productivity was constructed using the breeding method in collaboration with Korea Research Institute of Bioscience and Biotechnology. Three Deinococcal bioindicators for radiation dosage confirmation after radiation sterilization process were developed. These results provide a comprehensive information for novel functional genetic elements, enzymes, and physiological active substances production or application. Eventually, industrial microbial cell factories based on radiation resistant microbial genomes can be developed and the technologies can be diffused to bioindustry continuously by this project.

  5. Research of radiation-resistant microbial organisms

    International Nuclear Information System (INIS)

    Kim, Dongho; Lim, Sangyong; Joe, Minho; Park, Haejoon; Song, Hyunpa; Im, Seunghun; Kim, Haram; Kim, Whajung; Choi, Jinsu; Park, Jongchun

    2012-01-01

    Many extremophiles including radiation-resistant bacteria Deinococcus radiodurans have special characteristics such as novel enzymes and physiological active substances different from known biological materials and are being in the spotlight of biotechnology science. In this research, basic technologies for the production of new genetic resources and microbial strains by a series of studies in radiation-resistant microbial organisms were investigated and developed. Mechanisms required for radiation-resistant in Deinococcus radiodurans were partly defined by analyzing the function of dinB, pprI, recG, DRA 0 279, pprM, and two-component signal transduction systems. To apply genetic resource and functional materials from Deinococcus species, omics analysis in response to cadmium, construction of macroscopic biosensor, and characterization of carotenoids and chaperon protein were performed. Additionally, potential use of D. geothermalis in monosaccharide production from non-biodegradable plant materials was evaluated. Novel radiation resistant yeasts and bacteria were isolated and identified from environmental samples to obtain microbial and genomic resources. An optimal radiation mutant breeding method was set up for efficient and rapid isolation of target microbial mutants. Furthermore, an efficient ethanol producing mutant strain with high production yield and productivity was constructed using the breeding method in collaboration with Korea Research Institute of Bioscience and Biotechnology. Three Deinococcal bioindicators for radiation dosage confirmation after radiation sterilization process were developed. These results provide a comprehensive information for novel functional genetic elements, enzymes, and physiological active substances production or application. Eventually, industrial microbial cell factories based on radiation resistant microbial genomes can be developed and the technologies can be diffused to bioindustry continuously by this project

  6. Acute Toxicity After Image-Guided Intensity Modulated Radiation Therapy Compared to 3D Conformal Radiation Therapy in Prostate Cancer Patients

    NARCIS (Netherlands)

    Wortel, Ruud C.; Incrocci, Luca; Pos, Floris J.; Lebesque, Joos V.; Witte, Marnix G.; van der Heide, Uulke A.; van Herk, Marcel; Heemsbergen, Wilma D.

    2015-01-01

    Purpose: Image-guided intensity modulated radiation therapy (IG-IMRT) allows significant dose reductions to organs at risk in prostate cancer patients. However, clinical data identifying the benefits of IG-IMRT in daily practice are scarce. The purpose of this study was to compare dose distributions

  7. Epidemiological survey of the effects of low level radiation dose: a comparative assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.S.B.

    1993-10-01

    This volume presents the collations tables of a six volume comparative epidemiological survey of the effects of low level radiation dose. Data are collated for the effects observed in the following irradiated groups:- Preconception irradiation, intra-uterine irradiation, childhood irradiation, adult irradiation. (UK).

  8. The Use of Carcasses for the Analysis of Cetacean Population Genetic Structure: A Comparative Study in Two Dolphin Species

    Science.gov (United States)

    Bilgmann, Kerstin; Möller, Luciana M.; Harcourt, Robert G.; Kemper, Catherine M.; Beheregaray, Luciano B.

    2011-01-01

    Advances in molecular techniques have enabled the study of genetic diversity and population structure in many different contexts. Studies that assess the genetic structure of cetacean populations often use biopsy samples from free-ranging individuals and tissue samples from stranded animals or individuals that became entangled in fishery or aquaculture equipment. This leads to the question of how representative the location of a stranded or entangled animal is with respect to its natural range, and whether similar results would be obtained when comparing carcass samples with samples from free-ranging individuals in studies of population structure. Here we use tissue samples from carcasses of dolphins that stranded or died as a result of bycatch in South Australia to investigate spatial population structure in two species: coastal bottlenose (Tursiops sp.) and short-beaked common dolphins (Delphinus delphis). We compare these results with those previously obtained from biopsy sampled free-ranging dolphins in the same area to test whether carcass samples yield similar patterns of genetic variability and population structure. Data from dolphin carcasses were gathered using seven microsatellite markers and a fragment of the mitochondrial DNA control region. Analyses based on carcass samples alone failed to detect genetic structure in Tursiops sp., a species previously shown to exhibit restricted dispersal and moderate genetic differentiation across a small spatial scale in this region. However, genetic structure was correctly inferred in D. delphis, a species previously shown to have reduced genetic structure over a similar geographic area. We propose that in the absence of corroborating data, and when population structure is assessed over relatively small spatial scales, the sole use of carcasses may lead to an underestimate of genetic differentiation. This can lead to a failure in identifying management units for conservation. Therefore, this risk should be carefully

  9. On the genetic effects of low-level tritium

    International Nuclear Information System (INIS)

    Hori, Tada-aka; Nakai, Sayaka

    1976-01-01

    Genetic risk assessment for potential hazard from environmental tritium to man becomes important with increasing nuclear-power industry. The purpose of this short review is to discuss the possible genetic effects of tritium from a view of genetic risk estimation. The discussion is based mainly on our experimental results on the chromosome aberrations induced in human lymphocytes by tritium at the very low-level. The types of chromosome aberrations induced by radiation from tritium incorporated into the cells are mostly chromatid types. The most interesting finding is that the dose-response relationship observed in both tritiated-water and tritiated-thymidine is composed of two phases. The examination on the nature of two-phase dose-response relationship is very important not only for the mechanisms of chromosome aberrations, but also for the evaluation of genetic risk from low-level radiation. (auth.)

  10. Radiation-induced Genomic Instability and Radiation Sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Varnum, Susan M.; Sowa, Marianne B.; Kim, Grace J.; Morgan, William F.

    2013-01-19

    The obvious relationships between reactive oxygen and nitrogen species, mitochondrial dysfunction, inflammatory type responses and reactive chemokines and cytokines suggests a general stress response induced by ionizing radiation most likely leads to the non-targeted effects described after radiation exposure. We argue that true bystander effects do not occur in the radiation therapy clinic. But there is no question that effects outside the target volume do occur. These “out of field effects” are considered very low dose effects in the context of therapy. So what are the implications of non-targeted effects on radiation sensitivity? The primary goal of therapy is to eradicate the tumor. Given the genetic diversity of the human population, lifestyle and environment factors it is likely some combination of these will influence patient outcome. Non-targeted effects may contribute to a greater or lesser extent. But consider the potential situation involving a partial body exposure due to a radiation accident or radiological terrorism. Non-targeted effects suggest that the tissue at risk for demonstrating possible detrimental effects of radiation exposure might be greater than the volume actually irradiated.

  11. Estimation of radiation hazard of global 85Kr

    International Nuclear Information System (INIS)

    Vasilenko, I.Ya.; Moskalev, Yu.I.; Istomina, A.G.

    1979-01-01

    The data on sources and levels of the 85 Kr biosphere contamination are presented on the basis of generalization and analysis of literature. The potential irradiation doses for people are calculated and the biological estimation of the hazard of 85 Kr accumulation in the atmosphere up to 2050 is given taking into account the prospects for development of nuclear power engineering. The basis of the estimation is the radionuclide blastomogeneous and genetic effect. The conclusion is made that the prospects for development of nuclear power engineering do not lead to any sufficient increase in the number of malignant tumors and genetic abnormalities caused by 85 Kr radiation comparing with their natural frequency

  12. Federal interagency radiation policy coordination

    International Nuclear Information System (INIS)

    Young, A.L.

    1984-01-01

    The author discusses Federal interagency radiation policy coordination. The Committee on Interagency Radiation Research and Policy Coordination (CIRRPC) is explained as being dedicated to the success and forward motion of enhanced radiation research and policy coordination. Both CIRRPC and the Science Panel are staffed with Federal employees. Their expertise includes many and various radiation disciplines including cytogenetics, dosimetry, epidemiology, genetics, health physics, nuclear medicine, radiology, radiation carcinogenesis, and risk assessment. Ten scientific and technical issues in their preliminary order are presented: radioepidemiological tables; de minimis radiation levels; radon progeny health effects; occupational exposure registry; measurement, recording, and control of radiation; food irradiation; use of radiation in science, industry, and medicine; nonionizing radiation; and remedial actions

  13. Cost-benefit as weighed on genetic scales

    International Nuclear Information System (INIS)

    Grahn, D.

    1976-01-01

    The genetic cost that may be incurred by exposure to mutagenic agents in the coal and nuclear fuel cycles is assessed, using as a point of departure the presently estimated burden of spontaneously occurring genetic defects in human populations. Risk estimates are necessarily derived from radiation studies, but chemical mutagenic hazards can probably be evaluated relative to the known dose-response relationships of radiation exposure. Cost-benefit analyses for the coal and nuclear fuel cycles are discussed and translated into monetary terms. Coal-associated risks are almost entirely somatic while nuclear risks are somatic and genetic in equal proportions. Dollar costs per man-rem are concluded to be in the $100 range. Pollution abatement costs for the nuclear cycle lie in the range of several hundreds to many thousands of dollars per man-rem reduction. It is considered appropriate to incur such costs, because genetic risks to future generations involve primarily societal and ethical issues rather than economic considerations

  14. DNA extraction methods for detecting genetically modified foods: A comparative study.

    Science.gov (United States)

    Elsanhoty, Rafaat M; Ramadan, Mohamed Fawzy; Jany, Klaus Dieter

    2011-06-15

    The work presented in this manuscript was achieved to compare six different methods for extracting DNA from raw maize and its derived products. The methods that gave higher yield and quality of DNA were chosen to detect the genetic modification in the samples collected from the Egyptian market. The different methods used were evaluated for extracting DNA from maize kernels (without treatment), maize flour (mechanical treatment), canned maize (sweet corn), frozen maize (sweet corn), maize starch, extruded maize, popcorn, corn flacks, maize snacks, and bread made from corn flour (mechanical and thermal treatments). The quality and quantity of the DNA extracted from the standards, containing known percentages of GMO material and from the different food products were evaluated. For qualitative detection of the GMO varieties in foods, the GMOScreen 35S/NOS test kit was used, to screen the genetic modification in the samples. The positive samples for the 35S promoter and/or the NOS terminator were identified by the standard methods adopted by EU. All of the used methods extracted yielded good DNA quality. However, we noted that the purest DNA extract were obtained using the DNA extraction kit (Roche) and this generally was the best method for extracting DNA from most of the maize-derived foods. We have noted that the yield of DNA extracted from maize-derived foods was generally lower in the processed products. The results indicated that 17 samples were positive for the presence of 35S promoter, while 34% from the samples were positive for the genetically modified maize line Bt-176. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Oxygen effect in radiation biology: caffeine and serendipity

    International Nuclear Information System (INIS)

    Kesavan, P.C.

    2005-01-01

    The 'hit theory' developed in 1920s to explain the actions of ionizing radiation on cells and organisms was purely physical, and its limitation was its inadequacy to address the contemporary findings such as the oxygen enhancement of radiobiological damage, and the increased radio- sensitivity of dividing compared to non-dividing cells. The textbooks written prior to 1970s did not either refer at all to oxygen as a radiosensitizer, or had mentioned it only in a passing manner; yet 'oxygen effect' was emerging as the central dogma in radiation biology. The oxygen effect in radiation biology is highly interdisciplinary encompassing atomic physics (i.e. interaction of photon with matter), radiation chemistry (formation of reactive oxygen species), molecular signalling, gene expression and genetic alterations in cells (mutation, cancer) or the cell death (apoptosis, necrosis, mitotic catastrophe, etc.). Cell death in higher organisms is now recognized as the precursor of possible error-free cell replacement repair. (author)

  16. Mutation studies upon spermatogonial stem cells of mammals and genetic tests for non-disjunction in the mouse

    International Nuclear Information System (INIS)

    Cattanach, B.M.

    1993-01-01

    Studies upon strain differences in genetic response to radiation may facilitate extrapolation of mouse data to man. The objective of the project is to investigate the basis of the genetic responses obtained with different treatment regimes. Two systems of genetic (complementation) tests were developed using Robertsonian translocations in tester animals to detect non-disjunction and chromosome loss events in normal mice. The aim is to evaluate the two methods for detecting chromosome 11 loss, and compare the frequency of chromosomes 11 and 13 loss following X-irradiation of males and females. (R.P.) 6 refs., 3 tabs

  17. Medical And Genetic Monitoring of Population Around Semipalatinsk Test-site

    International Nuclear Information System (INIS)

    Kayupova, N.A.; Svyatova, G.S.; Abildinova, G.Zh.

    1998-01-01

    Up to present, there is no one positive opinion about the effect of a small amount of ionizing radiation doses on the genetic system of a human being. In connection with it, the all-round medical and genetic researches conducted by a united methodical basis and intended to study general mutagen and teratogen radiation effects are of a certain significance. With that end in view, the medical and genetic testing of a number of rural population around Semipalatinsk test-site (STS) was conducted. The all-round methods of medical and genetic consequences evaluation were developed, and 'active revealing of the congenital fetation disease (CFD)' method was submitted for consideration. Aside from analysis of the general genetic and demographic data, outcomes of more than 160.000 confinements were studied, and a high frequency rate of the CFD of 'the strict recording' (6.11 per 1000 new-born children in areas of extreme radiation hazard) was discovered, that surely exceeded the similar index for the monitored areas (2.92 per 1000 new-born children). A higher frequency rate of the Down's syndrome and numerous CFD (1.66 and 1.07 per 1000 new-born children accordingly) were revealed as well. As a result of the cytogenetic monitoring of the tested population, it was ascertained that a total frequency rate of the aberrant cell emergence was equal to 4.9 per 100 cells, that is 3.9 times as much than the similar index for the monitored area. A high frequency rate of the markers induced by radiation was discovered, which proved the increased mutagen effect of the environment. Biological presentation of the radiation effect on population was conducted in two methods of the biological monitoring, and according to the frequency rate of the chromosomal aberrations in lymphocytes of peripheral blood, that are induced by radiation, and electro paramagnetic resonance of teeth enamel (Kazakhstan national Nuclear Center). The results of the medical and genetic research conducted were an

  18. Topical Day on Biological Effects of Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Baatout, S.; Jacquet, P.

    1997-05-15

    The topical day has been focussed on the potential effects of ionizing radiation on human health. A general overview on molecular and biophysical aspects of radiation, its effects on cells and organisms, and the contribution of radiobiology to radiation protection and risk assessment is given. The genetic effects of radiation and its effects on the developing organism, the effects of radiation on the cell cycle and the mechanisms of radiation induced apoptosis were also discussed.

  19. Topical Day on Biological Effects of Radiation

    International Nuclear Information System (INIS)

    Baatout, S.; Jacquet, P.

    1997-01-01

    The topical day has been focussed on the potential effects of ionizing radiation on human health. A general overview on molecular and biophysical aspects of radiation, its effects on cells and organisms, and the contribution of radiobiology to radiation protection and risk assessment is given. The genetic effects of radiation and its effects on the developing organism, the effects of radiation on the cell cycle and the mechanisms of radiation induced apoptosis were also discussed

  20. Tritium and other radionuclide labeled organic compounds incorporated in genetic material. NCRP report No. 63: National Council on Radiation Protection and Measurements

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This book has as its subject the radiation dose to cells from incorporated radioactive material. According to the authors, NCRP Scientific Committee 24, the most sensitive cellular material is the genetic material of DNA and RNA in the nucleus. The biological effects of exposure are examined, since each cell line has its own sensitivities and hazards, which must be taken into account when a particular radioactive material is considered. The various kinds of radiation injury may lead to cell death, failure to mature, tumor genesis, transmutation of nuclides leading to DNA breaks, and gene mutation. Some of these injuries are no more potent when the source is external, whereas others, such as transmutation, occur only inside cells. The method for dose calculation is based upon the concern for doses coming from heterogeneously distributed beta emitters. The critical volume is the nucleus of stem cells, since injury to stem cells leads to late somatic and genetic effects. The dose at issue is that to labeled stem cells, not the whole population of stem cells. On this basis a maximum permissible intake of the material in question is calculated

  1. Risks of increased UV-B radiation: higher plants

    International Nuclear Information System (INIS)

    Rau, W.; Hofmann, H.

    1994-01-01

    The question pursued within the Bavarian climate research programme (BayFORKLIM) in the present context was as follows: Does the fact that UV-B radiation increases with growing site elevation mean that the low sensitivity of predominantly alpine plants compared with that of lowland plants is attributable to their different genetic constitution, possibly as a result of selective pressure and/or de alpine species have a greater capacity to develop protective mechanisms? Pairs and triplets of species belonging to the same genus but occuring at different site elevations were grown from seeds in a greenhouse that is, without UV-B. In order to determine their capacity to adapt to UV-B radiation, some of the plants were additionally exposed to UV-B for 5-6 weeks prior to sensitivity testing. Sensitivity was tested by exposing the plants to additional UV-B of different intensities in test chambers. Visible damage, ranging from light bronzing or yellowing to withering, served as an assessment criterion. Levels of UV-B absorbing substances (phenylpropane species, usually flavonoids) were also measured in these plants. The results obtained permit the following conclusions: The greater UV-B resistance of alpine species compared with that of lowland species of the same genus is not attributable to their genetic constitution but rather to their superior adaptability. Superior resistance is in part due to a greater accumulation of UV-B absorbing substances. Distinct differences in sensitivity between different genera could lead to population shifts within ecosystems as a result of increased UV-B radiation. (orig./KW) [de

  2. Is energy imparted a good measure of the radiation risk associated with CT examinations

    International Nuclear Information System (INIS)

    Huda, W.

    1984-01-01

    The dose distribution in a Rando phantom has been measured for typical EMI 5005 CT scans of the head, chest, abdomen and pelvis. These dose distributions have been used to generate quantitative estimates of the somatic and genetic radiation risks associated with these CT examinations and also to measure the total energy imparted during each scan. A comparison has been made between the radiation risk estimates and the energy imparted measurements. The energy imparted measurements are not a good indicator of the somatic and/or genetic risks when one type of CT scan is compared with another. However, for a given type of scan, the energy imparted may be a reasonable indicator of the relative somatic risks associated with different CT examinations. Considerable care should be taken when interpreting and using any measured value of energy imparted in a radiological examination since published values of the risk per unit energy imparted can significantly underestimate the radiation risk. (author)

  3. Health protection of radiation workers

    International Nuclear Information System (INIS)

    Norwood, W.D.

    1975-01-01

    Essential information on the health protection of radiation workers which has accumulated since the advent of nuclear fission thirty years ago is presented in simple terms. Basic facts on ionizing radiation, its measurement, and dosimetry are presented. Acute and chronic somatic and genetic effects are discussed with emphasis on prevention. Radiation protection standards and regulations are outlined, and methods for maintaining these standards are described. Diagnosis and treatment of radiation injury from external radiation and/or internally deposited radionuclides is considered generally as well as specifically for each radioisotope. The medical supervision of radiation workers, radiation accidents, atomic power plants, and medicolegal problems is also covered. (853 references) (U.S.)

  4. Ionising radiation - physical and biological effects

    International Nuclear Information System (INIS)

    Holter, Oe.; Ingebretsen, F.; Parr, H.

    1979-01-01

    The physics of ionising radiation is briefly presented. The effects of ionising radiation on biological cells, cell repair and radiosensitivity are briefly treated, where after the effects on man and mammals are discussed and related to radiation doses. Dose limits are briefly discussed. The genetic effects are discussed separately. Radioecology is also briefly treated and a table of radionuclides deriving from reactors, and their radiation is given. (JIW)

  5. Dual responsive promoters to target therapeutic gene expression to radiation-resistant hypoxic tumor cells

    International Nuclear Information System (INIS)

    Chadderton, Naomi; Cowen, Rachel L.; Sheppard, Freda C.D.; Robinson, Suzanne; Greco, Olga; Scott, Simon D.; Stratford, Ian J.; Patterson, Adam V.; Williams, Kaye J.

    2005-01-01

    Purpose: Tumor hypoxia is unequivocally linked to poor radiotherapy outcome. This study aimed to identify enhancer sequences that respond maximally to a combination of radiation and hypoxia for use in genetic radiotherapy approaches. Methods and materials: The influence of radiation (5 Gy) and hypoxia (1% O 2 ) on reporter-gene expression driven by hypoxia (HRE) and radiation (Egr-1) responsive elements was evaluated in tumor cells grown as monolayers or multicellular spheroids. Hypoxia-inducible factor-1α (HIF-1α) and HIF-2α protein expression was monitored in parallel. Results: Of the sequences tested, an HRE from the phosphoglycerate kinase-1 gene (PGK-18[5+]) was maximally induced in response to hypoxia plus radiation in all 5 cell lines tested. The additional radiation treatment afforded a significant increase in the induction of PGK-18[5+] compared with hypoxia alone in 3 cell lines. HIF-1α/2α were induced by radiation but combined hypoxia/radiation treatment did not yield a further increase. The dual responsive nature of HREs was maintained when spheroids were irradiated after delivery of HRE constructs in a replication-deficient adenovirus. Conclusions: Hypoxia-responsive enhancer element sequences are dually responsive to combined radiation and hypoxic treatment. Their use in genetic radiotherapy in vivo could maximize expression in the most radio-resistant population at the time of radiation and also exploit microenvironmental changes after radiotherapy to yield additional switch-on

  6. Clinical impact of predictive assays for acute and late radiation morbidity

    International Nuclear Information System (INIS)

    Budach, W.; Classen, J.; Belka, C.; Bamberg, M.

    1998-01-01

    Background: Clinically reliable predictive assays for normal tissue radiation sensitivity would help to avoid severe radiation induced morbidity and result in individualized dose prescriptions. Profound differences of individual fibroblast and lymphocyte radiation sensitivity in vitro have been documented in patients with certain genetic syndromes but also in patients without known genetic disorders. The following review evaluates whether fibroblast or lymphocyte radiation sensitivity measured in vitro correlates with the degree of acute and late radiation induced morbidity. Results: Acute radiation side effects and lymphocyte sensitivity has been investigated in 2 studies. One of them reported an insecure correlation, the other no correlation at all. Fibroblast radiation sensitivity and the extent of acute radiation induced side effects on skin and mucosal sites has been compared in a total of 5 studies. None of these studies found a consistent significant correlation. Lymphocyte radiation sensitivity and late effects have been studied by 2 institutions. Late radiation induced skin and mucosal changes did not correlate with lymphocyte sensitivity in head and neck cancer patients, whereas in breast cancer patients a weak (R 2 =0.06) correlation between the degree of late skin reactions and lymphocyte sensitivity was observed. Late skin or mucosal radiation reactions and fibroblast sensitivity were examined by 5 research groups. Data analysis revealed significant correlations or at least a trend towards a significant correlation in all studies. The quality of the reported correlations expressed as R 2 ranged from 0.13 to 0.60, indicating a low predictive value. Conclusions: Lymphocyte radiation sensitivity as measured by currently available assays does not or only poorly correlate with acute and late effects of radiation in patients, precluding predictive tests based on lymphocyte sensitivity. Fibroblast radiation sensitivity does not correlate with acute but

  7. XRCC3 polymorphisms are associated with the risk of developing radiation-induced late xerostomia in nasopharyngeal carcinoma patients treated with intensity modulation radiated therapy.

    Science.gov (United States)

    Zou, Yan; Song, Tao; Yu, Wei; Zhao, Ruping; Wang, Yong; Xie, Ruifei; Chen, Tian; Wu, Bo; Wu, Shixiu

    2014-03-01

    The incidence of radiation-induced late xerostomia varies greatly in nasopharyngeal carcinoma patients treated with radiotherapy. The single-nucleotide polymorphisms in genes involved in DNA repair and fibroblast proliferation may be correlated with such variability. The purpose of this paper was to evaluate the association between the risk of developing radiation-induced late xerostomia and four genetic polymorphisms: TGFβ1 C-509T, TGFβ1 T869C, XRCC3 722C>T and ATM 5557G>A in nasopharyngeal carcinoma patients treated with Intensity Modulation Radiated Therapy. The severity of late xerostomia was assessed using a patient self-reported validated xerostomia questionnaire. Polymerase chain reaction-ligation detection reaction methods were performed to determine individual genetic polymorphism. The development of radiation-induced xerostomia associated with genetic polymorphisms was modeled using Cox proportional hazards, accounting for equivalent uniform dose. A total of 43 (41.7%) patients experienced radiation-induced late xerostomia. Univariate Cox proportional hazard analyses showed a higher risk of late xerostomia for patients with XRCC3 722 TT/CT alleles. In multivariate analysis adjusted for clinical and dosimetric factors, XRCC3 722C>T polymorphisms remained a significant factor for higher risk of late xerostomia. To our knowledge, this is the first study that demonstrated an association between genetic polymorphisms and the risk of radiation-induced late xerostomia in nasopharyngeal carcinoma patients treated with Intensity Modulation Radiated Therapy. Our findings suggest that the polymorphisms in XRCC3 are significantly associated with the risk of developing radiation-induced late xerostomia.

  8. Radiation safety

    International Nuclear Information System (INIS)

    Goetz, B.B.; Murphy, C.H.

    1987-01-01

    In medicine, as in other fields of scientific endeavor, the development of advanced and specialized techniques has resulted in increased hazards for employees. However, by possessing both an appreciation of the proper use of factors that regulate radiation exposure around radiology equipment and a knowledge of the biologic effects of radiation, which can include possible genetic and somatic consequences, it is possible to maximize the usefulness of these valuable procedures while minimizing the risk to medical personnel involved with patient care

  9. Comparative study of different surrogate markers for individual radiation sensitivity

    International Nuclear Information System (INIS)

    Hoffmann, Nele Julia

    2013-01-01

    Radiotherapy is an important part of therapeutic tumor treatment concept. The applied total dose is limited by the unavoidable radiation effect on the surrounding normal tissue and the risk of radiation induced acute or chronic side effects. The clinical radiation sensitivity, i.e. the risk of radiogenic side effects is strongly coupled to the cellular radiation sensitivity. The contribution is focused on the development of a predictive tool for the individual radiation sensitivity for individual radiotherapeutic planning using lymphocytes. Residual foci, i.e. accumulated repair associated proteins at the residual double strand break are supposed to be surrogate markers of the cellular radiation sensitivity. No relation between the foci detection and the G(0)/G(1) was found assay with respect to the individual radiation sensitivity.

  10. Effect of recB21, uvrD3, lexA101 and recF143 mutations on ultraviolet radiation sensitivity and genetic recombination in ΔuvrB strains of Escherichia coli K-12

    International Nuclear Information System (INIS)

    Wang, T.V.; Smith, K.C.

    1981-01-01

    The interaction of the recB21, uvrD3, lexA101, and recF143 mutations on UV radiation sensitization and genetic recombination was studied in isogenic strains containing all possible combinations of these mutations in a ΔuvrB genetic background. The relative UV radiation sensitivities of the multiply mutant strains in the ΔuvrB background were: recF recB lexA > recF recB uvrD lexA, recF recB uvrD > recA > recF uvrD lexA > recF recB, recF uvrD > recF lexA > recB uvrD lexA > recB uvrD > recB lexA, lexA uvrD > recB > lexA, uvrD > recF; three of these strains were more UV radiation sensitive than the uvrB recA strain. There was no correlation between the degree of radiation sensitivity and the degree of deficiency in genetic recombination. An analysis of the survival curves revealed that the recF mutation interacts synergistically with the recB, uvrD, and lexA mutations in UV radiation sensitization, while the recB, uvrD, and lexA mutations appear to interact additively with each other. We interpret these data to suggest that there are two major independent pathways for postreplication repair; one is dependent on the recF gene, and the other is dependent on the recB, uvrD, and lexA genes. (orig.)

  11. Toward the elucidation of factors concerning the individual difference of radiation sensitivity, and the reduction of radiation risks

    International Nuclear Information System (INIS)

    Nenoi, Mitsuru; Nakajima, Tetsuo; Wang, Bing

    2013-01-01

    This article describes studies aiming at the title subject and contains 2 topics of genetic and non-genetic factors modifying the radiation sensitivity. The ultimate purposes of those studies are the introduction of individual weighting factor to correct the individual differences of the sensitivity (IDS) and the practical control of the sensitivity-concerned factors, in the field of medical exposure. For genetic factors, described are studies on factors modifying the sensitivity at DNA repair and on the control of the sensitivity through the DNA repairing factors. The former, using cultured cells, aims at identifying protein (gene) of possible biomarker for IDS in non-homologous end-joining (NHEJ), an important mechanism in repairing the double strand break of DNA. Ku protein is found as the candidate. The latter has revealed that cells lacking Artemis, XRCC4 or MDC1 gene are highly sensitive, and are planning to suppress Artemis activity artificially, which may lead to the reduction of radiation cancer formation due to the death of highly sensitive cells. For non-genetic factors, described are studies on the life habits modifying the sensitivity, on the control of the sensitivity through the radiation-induced adaptive response and with steroid hormone. In the first, in mice treated with high-calorie diet and X-irradiation, a possible radiation response is suggested in the hepatic DNA-methylation and micro-RNA. Second, the combination of radiation adaptive response in the genome damage and restriction of diet ingestion is shown to lower the sensitivity of mice with use of C, Ne ion or X-ray irradiation. Third, in studies on the radiation-induced formation and condensation of breast cancer stem cells in the presence of progesterone, the hormone is found to produce micro-RNA molecules relating with the suppression of cellular senescence and repressed carcinogenesis with over-expression of apoptosis inhibitory molecules. (T.T.)

  12. Identifying novel genes for atherosclerosis through mouse-human comparative genetics

    NARCIS (Netherlands)

    Wang, XS; Ishimori, N; Korstanje, R; Rollins, J; Paigen, B

    Susceptibility to atherosclerosis is determined by both environmental and genetic factors. Its genetic determinants have been studied by use of quantitative- trait - locus ( QTL) analysis. So far, 21 atherosclerosis QTLs have been identified in the mouse: 7 in a high- fat - diet model only, 9 in a

  13. Radiation resistance and comparative performance of ITO/InP and n/p InP homojunction solar cells

    International Nuclear Information System (INIS)

    Weinberg, I.; Swartz, C.K.; Hart, R.E. Jr.; Coutts, T.J.

    1988-09-01

    The radiation resistance of ITO/InP cells processed by DC magnetron sputtering is compared to that of standard n/p InP and GaAs homojunction cells. After 20 MeV proton irradiations, it is found that the radiation resistance of the present ITO/InP cell is comparable to that of the n/p homojunction InP cell and that both InP cell types have radiation resistance significantly greater than GaAs. The relatively lower radiation resistance, observed at higher fluence, for the InP cell with the deepest junction depth, is attributed to losses in the cells emitter region. Diode parameters obtained from I sub sc - V sub oc plots, data from surface Raman spectroscopy, and determinations of surface conductivity types are used to investigate the configuration of the ITO/InP cells. It is concluded that thesee latter cells are n/p homojunctions, the n-region consisting of a disordered layer at the oxide semiconductor

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

    International Nuclear Information System (INIS)

    AlSuhaibani, E.S

    2008-01-01

    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)

  15. Individual radiation sensitivity: implications in medical practice

    Energy Technology Data Exchange (ETDEWEB)

    Gisone, P.; Dubner, D.; Perez, M.D.R.; Michelin, S.; Di Giogio, M. [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina); Bourguignon, M. [Direction Generale de la Surete Nucleaire et de la Radioprotection, Paris (France)

    2006-07-01

    Important advances in radiotherapy and nuclear medicine towards better treatment modalities and safer applications have taken place in recent years. Progress in medical imaging, better tumour targeting and optimization of radiation delivery have allowed for dose escalation and improved patient outcome. However, the tolerance of normal tissues constitutes the limiting factor for dose escalation in therapeutical uses of ionizing radiation (IR). Patients vary considerably in their normal tissue response to IR even after similar treatments. As many as 5% of cancer patients develop severe effects to external radiation therapy in normal tissues within the treatment field: they may include acute effects such as erythema and desquamation of the exposed skin and mucosa that appear during or directly after radiotherapy, late effects developed months or years later, such as fibrosis and telangiectasia and cancer induction. Several patient and treatment related factors are known to influence the variability of side effects, however up to a 70% of the total variance of normal tissue radiation response remained unexplained. Thus, individual sensitivity to IR, i.e. hypersensitivity to carcinogenic risks (stochastic effects) and hypersensitivity to deterministic effects, is becoming an important issue in oncology and raises questions regarding the underlying mechanisms. The mechanisms of DNA repair, the signalling pathways involved in radiation sensitivity and non-targeted effects are key aspects, essential to understanding radiation effects at genetic level. Moreover, human genetic diseases that combine higher incidence of cancer and hypersensitivity to IR are associated with defects in cell response to DNA damage. Therefore, much interest has raised during the last years in the developing of predictive tests capable to detect in advance such hypersensitive conditions. The goal of this presentation is to review the possible mechanisms involved in genetic and epigenetic

  16. Individual radiation sensitivity: implications in medical practice

    International Nuclear Information System (INIS)

    Gisone, P.; Dubner, D.; Perez, M.D.R.; Michelin, S.; Di Giogio, M.; Bourguignon, M.

    2006-01-01

    Important advances in radiotherapy and nuclear medicine towards better treatment modalities and safer applications have taken place in recent years. Progress in medical imaging, better tumour targeting and optimization of radiation delivery have allowed for dose escalation and improved patient outcome. However, the tolerance of normal tissues constitutes the limiting factor for dose escalation in therapeutical uses of ionizing radiation (IR). Patients vary considerably in their normal tissue response to IR even after similar treatments. As many as 5% of cancer patients develop severe effects to external radiation therapy in normal tissues within the treatment field: they may include acute effects such as erythema and desquamation of the exposed skin and mucosa that appear during or directly after radiotherapy, late effects developed months or years later, such as fibrosis and telangiectasia and cancer induction. Several patient and treatment related factors are known to influence the variability of side effects, however up to a 70% of the total variance of normal tissue radiation response remained unexplained. Thus, individual sensitivity to IR, i.e. hypersensitivity to carcinogenic risks (stochastic effects) and hypersensitivity to deterministic effects, is becoming an important issue in oncology and raises questions regarding the underlying mechanisms. The mechanisms of DNA repair, the signalling pathways involved in radiation sensitivity and non-targeted effects are key aspects, essential to understanding radiation effects at genetic level. Moreover, human genetic diseases that combine higher incidence of cancer and hypersensitivity to IR are associated with defects in cell response to DNA damage. Therefore, much interest has raised during the last years in the developing of predictive tests capable to detect in advance such hypersensitive conditions. The goal of this presentation is to review the possible mechanisms involved in genetic and epigenetic

  17. Medical effects of low doses of ionising radiation

    International Nuclear Information System (INIS)

    Coggle, J.E.

    1990-01-01

    Ionising radiation is genotoxic and causes biological effects via a chain of events involving DNA strand breaks and 'multiply damaged sites' as critical lesions that lead to cell death. The acute health effects of radiation after doses of a few gray, are due to such cell death and consequent disturbance of cell population kinetics. Because of cellular repair and repopulation there is generally a threshold dose of about 1-2 Gy below which such severe effects are not inducible. However, more subtle, sub-lethal mutational DNA damage in somatic cells of the body and the germ cells of the ovary and testis cause the two major low dose health risks -cancer induction and genetic (heritable) effects. This paper discusses some of the epidemiological and experimental evidence regarding radiation genetic effects, carcinogenesis and CNS teratogenesis. It concludes that current risk estimates imply that about 3% of all cancers; 1% of genetic disorders and between 0% and 0.3% of severe mental subnormality in the UK is attributable to the ubiquitous background radiation. The health risks associated with the medical uses of radiation are smaller, whilst the nuclear industry causes perhaps 1% of the health detriment attributable to background doses. (author)

  18. Radiation dose of cone-beam computed tomography compared to conventional radiographs in orthodontics.

    Science.gov (United States)

    Signorelli, Luca; Patcas, Raphael; Peltomäki, Timo; Schätzle, Marc

    2016-01-01

    The aim of this study was to determine radiation doses of different cone-beam computed tomography (CBCT) scan modes in comparison to a conventional set of orthodontic radiographs (COR) by means of phantom dosimetry. Thermoluminescent dosimeter (TLD) chips (3 × 1 × 1 mm) were used on an adult male tissue-equivalent phantom to record the distribution of the absorbed radiation dose. Three different scanning modes (i.e., portrait, normal landscape, and fast scan landscape) were compared to CORs [i.e., conventional lateral (LC) and posteroanterior (PA) cephalograms and digital panoramic radiograph (OPG)]. The following radiation levels were measured: 131.7, 91, and 77 μSv in the portrait, normal landscape, and fast landscape modes, respectively. The overall effective dose for a COR was 35.81 μSv (PA: 8.90 μSv; OPG: 21.87 μSv; LC: 5.03 μSv). Although one CBCT scan may replace all CORs, one set of CORs still entails 2-4 times less radiation than one CBCT. Depending on the scan mode, the radiation dose of a CBCT is about 3-6 times an OPG, 8-14 times a PA, and 15-26 times a lateral LC. Finally, in order to fully reconstruct cephalograms including the cranial base and other important structures, the CBCT portrait mode must be chosen, rendering the difference in radiation exposure even clearer (131.7 vs. 35.81 μSv). Shielding radiation-sensitive organs can reduce the effective dose considerably. CBCT should not be recommended for use in all orthodontic patients as a substitute for a conventional set of radiographs. In CBCT, reducing the height of the field of view and shielding the thyroid are advisable methods and must be implemented to lower the exposure dose.

  19. Retrospective genetic study of germinative mutations in Str loci of individuals potentially exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Costa, Emilia Oliveira Alves

    2010-01-01

    The Brazilian radiological accident that occurred in 1987, in Goiania, it was a terrible radiation episode. As a consequence, hundreds of people were contaminated due to the Cesium-137 radiation. Recently, many studies had shown that genome instabilities, such as, mutations, chromosomal aberrations, micronuclei formation and micro satellite instability and a delay on cellular death are usually reported on mammal cells exposed to ionizing radiation, being considered as a manly risk to humans. Mutations can be spontaneous, and the occurrence is dependent on the organism, or, induced, being associated to mutagenic exposition. Ionizing radiations are an example of physical and mutagenic agents that could harm the cell repair and could cause the development of many types of cancer. The evaluation of the biological effects of the ionizing radiation, in somatic and germ line cells, with a consequent determination of the radio-induced mutations, it is extremely important to estimate the genetic risks, manly in population exposed to radiation. The analyses of repetitive DNA sequences have been demonstrated that such sequences are prone to high rates of spontaneous mutations. The minisatellites and microsatellites have been used to demonstrate the induction of germ line mutation rates on mouse, humans, among others organisms. The aim of the present study was to analyze the frequency of microsatellite alterations to determine the mutation rates occurred in germ cells of the parents exposed to the ionizing radiation of the Cesium-137. The studied group was constitute of 10 families of individuals accidentally exposed to Cesium-137 and by the control group constituted by 645 healthy individuals who carried out paternity tests on 2009. We found only one mutation of paternal origin in the D8S1179 locus on the exposed group, being the mutation rate of 0.002. In the control group, we found 01 mutation on D16S539 loei and on D3S1358; 02 mutations on Penta E loeus; 04 mutations on D

  20. We can do better than effective dose for estimating or comparing low-dose radiation risks

    International Nuclear Information System (INIS)

    Brenner, D.J.

    2012-01-01

    The effective dose concept was designed to compare the generic risks of exposure to different radiation fields. More commonly these days, it is used to estimate or compare radiation-induced cancer risks. For various reasons, effective dose represents flawed science: for instance, the tissue-specific weighting factors used to calculate effective dose are a subjective mix of different endpoints; and the marked and differing age and gender dependencies for different health detriment endpoints are not taken into account. This paper suggests that effective dose could be replaced with a new quantity, ‘effective risk’, which, like effective dose, is a weighted sum of equivalent doses to different tissues. Unlike effective dose, where the tissue-dependent weighting factors are a set of generic, subjective committee-defined numbers, the weighting factors for effective risk are simply evaluated tissue-specific lifetime cancer risks per unit equivalent dose. Effective risk, which has the potential to be age and gender specific if desired, would perform the same comparative role as effective dose, be just as easy to estimate, be less prone to misuse, be more directly understandable, and would be based on solid science. An added major advantage is that it gives the users some feel for the actual numerical values of the radiation risks they are trying to control.

  1. Evaluation of the role of genetic factors in human radioresistance

    International Nuclear Information System (INIS)

    Telnov, Vitaliy I.; Sotnik, Natalie V.

    2002-01-01

    This study was focused on evaluation of the role of genetic factors in development of chronic radiation sickness (CRS) due to occupational exposure to external γ -rays. This study was based on results of molecular-genetic studies for 985 nuclear workers of the Mayak Production Association. CRS occurrence was related to the genetic haptoglobin (Hp) system among a number of studied genetic markers. Excess risk of CRS was revealed at similar exposure doses for individuals-carriers of Hp 2-2 (1.96) versus lower risks for carriers of Hp 1-1 and 2-1 (0.64). The contribution of genetic factors to CRS development was implemented in a rather narrow dose range, i.e. it was of a relative nature. A scheme of the relationship of affecting factor and differences in genetic radioresistance was presented in terms of deterministic effects. The obtained data did not confirm the idea that A-bomb survivors were more radioresistant, thus being not representative for radiation risk estimation

  2. Radiation induced genomic instability

    International Nuclear Information System (INIS)

    Morgan, W.

    2003-01-01

    This presentation will focus on delayed genetic effects occurring in the progeny of cells after exposure to ionizing radiation. We have developed a model system for investigating those genetic effects occurring multiple generations after radiation exposure. The presentation will describe some of the delayed effects observed after radiation exposures including delayed chromosomal rearrangements, and recombination events as determined by a plasmid based assay system. We will present new data on how changes in gene expression as measured by differential display and DNA microarray analysis provides a mechanism by which cells display a memory of irradiation, and introduce candidate genes that may play a role in initiating and perpetuation the unstable phenotype. These results will be discussed in terms of the recently described non-targeted Death Inducing Effect (DIE) where by secreted factors from clones of unstable cells can elicit effects in non irradiated cells and may serve to perpetuate the unstable phenotype in cells that themselves were not irradiated

  3. A-bomb radiation effects digest

    International Nuclear Information System (INIS)

    Shigematsu, Itsuzo; Akiyama, Mitoshi; Sasaki, Hideo; Ito, Chikako; Kamada, Nanao.

    1993-01-01

    This publication is the digest of the book 'Genbaku Hoshasen no Jintai Eikyo (Effects of A-bomb Radiation on the Human Body)' (365p.), published in Japanese by Hiroshima International Council for Medical Care of the Radiation-Exposed. Following a brief description on the damage of the atomic bomb, the subjects of malignant tumors, endocrine and metabolic deseases, ocular lesions, dermatologic effects, prenatal exposure, chromosoal aberrations, mutations, sensitivity to radiation, immune function, genetic effects and other effects of radiation are summarized. (J.P.N.)

  4. Comparative Genetic Analyses of Human Rhinovirus C (HRV-C) Complete Genome from Malaysia

    Science.gov (United States)

    Khaw, Yam Sim; Chan, Yoke Fun; Jafar, Faizatul Lela; Othman, Norlijah; Chee, Hui Yee

    2016-01-01

    Human rhinovirus-C (HRV-C) has been implicated in more severe illnesses than HRV-A and HRV-B, however, the limited number of HRV-C complete genomes (complete 5′ and 3′ non-coding region and open reading frame sequences) has hindered the in-depth genetic study of this virus. This study aimed to sequence seven complete HRV-C genomes from Malaysia and compare their genetic characteristics with the 18 published HRV-Cs. Seven Malaysian HRV-C complete genomes were obtained with newly redesigned primers. The seven genomes were classified as HRV-C6, C12, C22, C23, C26, C42, and pat16 based on the VP4/VP2 and VP1 pairwise distance threshold classification. Five of the seven Malaysian isolates, namely, 3430-MY-10/C22, 8713-MY-10/C23, 8097-MY-11/C26, 1570-MY-10/C42, and 7383-MY-10/pat16 are the first newly sequenced complete HRV-C genomes. All seven Malaysian isolates genomes displayed nucleotide similarity of 63–81% among themselves and 63–96% with other HRV-Cs. Malaysian HRV-Cs had similar putative immunogenic sites, putative receptor utilization and potential antiviral sites as other HRV-Cs. The genomic features of Malaysian isolates were similar to those of other HRV-Cs. Negative selections were frequently detected in HRV-Cs complete coding sequences indicating that these sequences were under functional constraint. The present study showed that HRV-Cs from Malaysia have diverse genetic sequences but share conserved genomic features with other HRV-Cs. This genetic information could provide further aid in the understanding of HRV-C infection. PMID:27199901

  5. Comparative population genetics of the German shepherd dog in South Africa

    Directory of Open Access Journals (Sweden)

    N. J. Coutts

    2010-01-01

    Full Text Available Modern breeding practices strive to achieve distinctive phenotypic uniformity in breeds of dogs, but these strategies are associated with the inevitable loss of genetic diversity. Thus, in parallel with the morphological variation displayed by breeds, purebred dogs commonly express genetic defects as a result of the inbreeding associated with artificial selection and the reduction of selection against disease phenotypes. Microsatellite marker analyses of 15 polymorphic canine loci were used to investigate measures of genetic diversity and population differentiation within and between German-bred and South African-bred German shepherd dogs. These data were quantified by comparison with typically outbred mongrel or crossbred dogs. Both the imported and locally-bred German shepherd dogs exhibited similar levels of genetic diversity. The breed is characterised by only a moderate loss of genetic diversity relative to outbred dogs, despite originating from a single founding sire and experiencing extensive levels of inbreeding throughout the history of the breed. Non-significant population differentiation between the ancestral German and derived South African populations indicates sufficient contemporary gene flow between these populations, suggesting that migration resulting from the importation of breeding stock has mitigated the effects of random genetic drift and a population bottleneck caused by the original founder event in South Africa. Significant differentiation between the combined German shepherd dog population and the outbred dogs illustrates the effects of selection and genetic drift on the breed since its establishment just over 100 years ago.

  6. Influence of some exo nucleases in response to the induced genetic damage in Escherichia coli by alpha radiation

    International Nuclear Information System (INIS)

    Aguilar M, M.

    2005-01-01

    Within the strategies with those that E. coli counts to overcome to the genetic damage there is the SOS response, a group of genes that participate in repair and/or tolerance that it confers to the bacteria major opportunities of surviving. These genes are repressed and its only are expressed when it happens genetic damage. So that this system is activated it is necessary that DNA of a band exists and in this sense the double ruptures (RDB) its are not able to induce this response unless there is a previous processing. In stumps with defects in certain genes that have to do with repair of RDB (as recO, recJ and xonA) the activity of SOS is smaller than in a wild stump what suggests that these participate in the previous processes to the activation of the response. The ionizing radiation produce among other many lesions, RDB in greater or smaller proportion, depending on the ionization capacity. A parameter to evaluate this capacity is the lineal energy transfer (LET), defined as the average energy given by unit of distance travelled. In general the LET of the corpuscular radiations is a lot but high that of the electromagnetic one, for what produces bigger quantity of ionizations inside a restricted zone and it increases by this way the probability that RDB has been generated. This work has for object to infer the participation of xonA and recJ in this response and to evaluate the damage produced by ionizing radiation of different LET (alpha particles of different energies) in a stump with all the functional repair mechanisms. Its were considered two parameters: the survival and the activity of SOS evaluated by means of the chromo test. The results indicate that the activity of these exo nucleases is necessary for the repair of RDB as well as for the processing of lesions foresaw to the activation of SOS. As for the treatment with alphas of different energies is observed that so much the survival like the activity of SOS vary as the LET of the radiation changes

  7. Comparative studies on the effect of radiation-sensitizing agents used in radiating VX2 Carcinoma

    International Nuclear Information System (INIS)

    Migita, Hidenobu

    1975-01-01

    The effects of 5-Fu and BUdR as radiation-sensitizing agents macroscopically were investigated in 122 VX2 Carcinomas transplanted into the calves of the hind legs of rabbits. Experimental groups and contrast groups are divided into six as follows: A: No treatment, B: 5-Fu infusion, C: BUdR+Antimetabolite infusion, D: Radiation, E: 5-Fu infusion and radiation, and F: BUdR+Antimetabolite infusion and radiation. The amount of agent given to each was 5 mg/kg/day of 5-Fu and 50 mg/kg/day of BUdR, and the amount of radiation was 300 rad/day. 5-Fu was used as the Antimetabolite, and its amount was one-tenth of that in the 5-Fu Infusion Group. The agent and the radiation were given for five days. 1. In the 300 rad/day Group, the radiation was not enough to result in a complete cure. 2. In the two Agent Infusion Group, 5-Fu and BUdR+Antimetabolite proved to be anti-cancer, but neither of them resulted in effective treatment. 3. The 5-Fu Infusion and Radiation Group, showed a strong degenerative change in the tumor cell and a radiosensitive effect from 5-Fu, but the tumor was not lessened. 4. In the BUdR-Antimetabolite Infusion and Radiation Group, the tumor began to reduce on the third day. On the seventh and fourteenth days, necrosis of the greater part of tumor was seen, and the rest of the tumor cells were found to be in degenerative change. On the twenty first day, no live tumor cell was found, only dead remains of tumor cells. The results were confirmed both macroscopically and histopathologically. 5. BUdR can be expected to be effective in clinical application to oral malignant tumors. (Evans, J.)

  8. Influence of XRCC1 Genetic Polymorphisms on Ionizing Radiation-Induced DNA Damage and Repair

    Directory of Open Access Journals (Sweden)

    Silvia Sterpone

    2010-01-01

    Full Text Available It is well known that ionizing radiation (IR can damage DNA through a direct action, producing single- and double-strand breaks on DNA double helix, as well as an indirect effect by generating oxygen reactive species in the cells. Mammals have evolved several and distinct DNA repair pathways in order to maintain genomic stability and avoid tumour cell transformation. This review reports important data showing a huge interindividual variability on sensitivity to IR and in susceptibility to developing cancer; this variability is principally represented by genetic polymorphisms, that is, DNA repair gene polymorphisms. In particular we have focussed on single nucleotide polymorphisms (SNPs of XRCC1, a gene that encodes for a scaffold protein involved basically in Base Excision Repair (BER. In this paper we have reported and presented recent studies that show an influence of XRCC1 variants on DNA repair capacity and susceptibility to breast cancer.

  9. Influence of XRCC1 Genetic Polymorphisms on Ionizing Radiation-Induced DNA Damage and Repair.

    Science.gov (United States)

    Sterpone, Silvia; Cozzi, Renata

    2010-07-25

    It is well known that ionizing radiation (IR) can damage DNA through a direct action, producing single- and double-strand breaks on DNA double helix, as well as an indirect effect by generating oxygen reactive species in the cells. Mammals have evolved several and distinct DNA repair pathways in order to maintain genomic stability and avoid tumour cell transformation. This review reports important data showing a huge interindividual variability on sensitivity to IR and in susceptibility to developing cancer; this variability is principally represented by genetic polymorphisms, that is, DNA repair gene polymorphisms. In particular we have focussed on single nucleotide polymorphisms (SNPs) of XRCC1, a gene that encodes for a scaffold protein involved basically in Base Excision Repair (BER). In this paper we have reported and presented recent studies that show an influence of XRCC1 variants on DNA repair capacity and susceptibility to breast cancer.

  10. Radiation-induced mammary carcinogenesis in rodent models. What's different from chemical carcinogenesis?

    International Nuclear Information System (INIS)

    Imaoka, Tatsuhiko; Nishimura, Mayumi; Iizuka, Daisuke; Daino, Kazuhiro; Takabatake, Takashi; Okamoto, Mieko; Kakinuma, Shizuko; Shimada, Yoshiya

    2009-01-01

    Ionizing radiation is one of a few well-characterized etiologic factors of human breast cancer. Laboratory rodents serve as useful experimental models for investigating dose responses and mechanisms of cancer development. Using these models, a lot of information has been accumulated about mammary gland cancer, which can be induced by both chemical carcinogens and radiation. In this review, we first list some experimental rodent models of breast cancer induction. We then focus on several topics that are important in understanding the mechanisms and risk modification of breast cancer development, and compare radiation and chemical carcinogenesis models. We will focus on the pathology and natural history of cancer development in these models, genetic changes observed in induced cancers, indirect effects of carcinogens, and finally risk modification by reproductive factors and age at exposure to the carcinogens. In addition, we summarize the knowledge available on mammary stem/progenitor cells as a potential target of carcinogens. Comparison of chemical and radiation carcinogenesis models on these topics indicates certain similarities, but it also indicates clear differences in several important aspects, such as genetic alterations of induced cancers and modification of susceptibility by age and reproductive factors. Identification of the target cell type and relevant translational research for human risk management may be among the important issues that are addressed by radiation carcinogenesis models. (author)

  11. Genomic instability and radiation

    Energy Technology Data Exchange (ETDEWEB)

    Little, John B [Harvard School of Public Health, Boston, MA 02115 (United States)

    2003-06-01

    Genomic instability is a hallmark of cancer cells, and is thought to be involved in the process of carcinogenesis. Indeed, a number of rare genetic disorders associated with a predisposition to cancer are characterised by genomic instability occurring in somatic cells. Of particular interest is the observation that transmissible instability can be induced in somatic cells from normal individuals by exposure to ionising radiation, leading to a persistent enhancement in the rate at which mutations and chromosomal aberrations arise in the progeny of the irradiated cells after many generations of replication. If such induced instability is involved in radiation carcinogenesis, it would imply that the initial carcinogenic event may not be a rare mutation occurring in a specific gene or set of genes. Rather, radiation may induce a process of instability in many cells in a population, enhancing the rate at which the multiple gene mutations necessary for the development of cancer may arise in a given cell lineage. Furthermore, radiation could act at any stage in the development of cancer by facilitating the accumulation of the remaining genetic events required to produce a fully malignant tumour. The experimental evidence for such induced instability is reviewed. (review)

  12. Genomic instability and radiation

    International Nuclear Information System (INIS)

    Little, John B

    2003-01-01

    Genomic instability is a hallmark of cancer cells, and is thought to be involved in the process of carcinogenesis. Indeed, a number of rare genetic disorders associated with a predisposition to cancer are characterised by genomic instability occurring in somatic cells. Of particular interest is the observation that transmissible instability can be induced in somatic cells from normal individuals by exposure to ionising radiation, leading to a persistent enhancement in the rate at which mutations and chromosomal aberrations arise in the progeny of the irradiated cells after many generations of replication. If such induced instability is involved in radiation carcinogenesis, it would imply that the initial carcinogenic event may not be a rare mutation occurring in a specific gene or set of genes. Rather, radiation may induce a process of instability in many cells in a population, enhancing the rate at which the multiple gene mutations necessary for the development of cancer may arise in a given cell lineage. Furthermore, radiation could act at any stage in the development of cancer by facilitating the accumulation of the remaining genetic events required to produce a fully malignant tumour. The experimental evidence for such induced instability is reviewed. (review)

  13. Risks and hazards from conventional and radiation sources

    International Nuclear Information System (INIS)

    Iyer, P.S.; Ganguly, A.K.

    1978-01-01

    Beneficial uses of radioisotopes in medicine, industry, agriculture and research are discussed. In absence of adequate safety precautions, uses of radiation may also result in harmful biological effects or genetic effects. Radiation risks and hazards are evaluated by comparing with other risks and hazards which are routinely encountered. The risk of fatality per year by various causes in U.S.A. is given. It is stated with examples and observations that some of the routine habits and necessities and minor luxuries are more risky than radiation risks. Countrywide radiation safety program in India by the Department of Atomic Energy is described in brief. Data are given to show that the risks from radiation are much lower in comparison with many conventional sources. More efficient equipment such as image intensifier is recommended to help to reduce the patient dose. It is stated that caution has to be exercised while handling the X-ray machines which may be harmful not only to patients but to doctors also. As regards, nuclear medicine, it is mentioned that though it is a fast expanding speciality in India, the number of procedures carried out in various centres is small as compared to U.S.A. and France. Some instances are given to show the consequences of the ignorance of the radiation hazards in operating machines in X-ray and gamma ray beam therapy facilities. A survey made by DRP, BARC revealed that some research laboratories lacked basic radiation protection requirements in using X-ray crystallography or analytical equipment. (B.G.W.)

  14. Estimation of radiation risks at low dose

    International Nuclear Information System (INIS)

    1990-04-01

    The report presents a review of the effects caused by radiation in low doses, or at low dose rates. For the inheritable (or ''genetic''), as well as for the cancer producing effects of radiation, present evidence is consistent with: (a) a non-linear relationship between the frequency of at least some forms of these effects, with comparing frequencies caused by doses many times those received annually from natural sources, with those caused by lower doses; (b) a probably linear relationship, however, between dose and frequency of effects for dose rates in the region of that received from natural sources, or at several times this rate; (c) no evidence to indicate the existence of a threshold dose below which such effects are not produced, and a strong inference from the mode of action of radiation on cells at low dose rates that no such thresholds are likely to apply to the detrimental, cancer-producing or inheritable, effects resulting from unrepaired damage to single cells. 19 refs

  15. Radiation. Doses, effect, risk

    International Nuclear Information System (INIS)

    Vapirev, E.; Todorov, P.

    1994-12-01

    This book outlines in a popular form the topic of ionizing radiation impacts on living organisms. It contains data gathered by ICRP for a period of 35 years. The essential dosimetry terms and units are presented. Natural and artificial sources of ionizing radiation are described. Possible biological radiation effects and diseases as a consequence of external and internal irradiation at normal and accidental conditions are considered. An assessment of genetic risk for human populations is presented and the concept of 'acceptable risk' is discussed

  16. Immunological aspects of light radiation sensitivity

    International Nuclear Information System (INIS)

    Hellman, K.B.; Schuller, G.B.

    1981-01-01

    The immune system comprises one aspect of the host's defense mechanism against potentially harmful agents. It has become recognized as an important factor in light radiation sensitivity and light-mediated disease. The interaction of light radiation with the immune system has formed the basis for the evolving discipline of photoimmunology. A description of the multicomponent immune system, its modification by light radiation, and a discussion of how photoimmunological studies may provide data important for understanding the mechanisms involved in photosensitivity are presented in this review. Photosensitivity may be either acquired or may be genetic in nature. Acquired photosensitivity involves an individual's reaction to either light alone or light in conjunction with topically or systemically administered photosenitizing agents. The outcome of such a reaction can be benign or severe, depending on a number of factors. Genetic photosensitivity includes the reactions to light radiation of individuals carrying the genetic information for inherited diseases such as Ataxia telangiectasia (AT) and Xeroderma pigmentosum (XP). Factors associated with these conditions can lead to enhanced sensitivity to radiation-related diseases, such as cancer. In addition, there are conditions which cannot be readily placed in either of the categories just described but, nevertheless, have been correlated with immune system dysfunction. These include photoallergy, photosensitivity associated with autoimmunity, and light-induced skin cancer. Immunological studies have provided information which may aid in elucidating the problem of photosensitivity and in the development of suitable radioprotective measures

  17. Isotopes and Radiation in Entomology. Proceedings of a Symposium on the Use of Isotopes and Radiation in Entomology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1968-06-15

    Proceedings of a Symposium jointly organized by the IAEA and the Food and Agriculture Organization of the United Nations and held in Vienna, 4-8 December 1967. The meeting was attended by 82 participants from 29 countries and six international organizations. Contents: Isotope applications - ecology (7 papers); Radiation effect studies - non-genetic (8 papers); Isotope applications - physiology and biochemistry (2 papers); Isotope applications - chemosterilants (2 papers); Sterile-male technique (9 papers); Radiation effect studies - genetic (5 papers); Isotope applications - genetic (1 paper). Each paper is in its original language (21 English, 11 French, 1 Russian and 1 Spanish) and is preceded by an abstract in English with a second one in the original language if this is not English. Discussions are in English. (author)

  18. Ionizing radiations: effects and sources

    International Nuclear Information System (INIS)

    Vignes, S.; Nenot, J.C.

    1978-01-01

    Having first mentioned the effects of ionizing radiations in cancerogenisis, pre-natal, and genetic fields, the authors present the different sources of radiations and estimate their respective contributions to the total irradiation dose. Their paper makes reference to the main elements of a report issued by the United Nations Scientific Committee in 1977 [fr

  19. Combined genetic effects of chemicals and radiation

    International Nuclear Information System (INIS)

    Kada, T.; Inoue, T.; Yokoiyama, A.; Russell, L.B.

    1979-01-01

    The interactions of chemicals and radiation are complex, and there may exist other unexpected patterns. The photodynamic induction of mutation by fluorescein dyes, and the radiosensitization with iodine compounds are classified as the interactions of chemicals and radiation outside cells. On the other hand, the antimutagenic effects of cobaltous chloride is concerned with the events taking place in the cells that had already been exposed to mutagenic agents. It is likely that the action of mutagenic agents is not direct, and that cellular functions, such as mutators or repair systems, are involved in the mutagenesis initiated by the agents. Such cellular functions can be affected by a second agent. In sexually reproducing organisms, two agents can also act on separate cells (male and female germ cells) which subsequently fuse. In mice, the experiments combining the radiation applied to one sex with the chemicals given to the other sex are only in early stages. Males were irradiated with X-ray (spermatozoa and spermatids sampled) and females (mature oocytes) were treated with caffeine. When the endpoint was dominant lethal, the level of X-ray effect induced in the male genome was independent of the caffeine treatment of the female. However, when the endpoint was sex-chromosome-loss, and a different strain of female was used, the caffeine potentiation was statistically significant at 5% level. (Yamashita, S.)

  20. Genetic risk from diagnostic X-ray procedures

    International Nuclear Information System (INIS)

    Stephan, G.

    1980-01-01

    This essay introduces epidemiologic studies concerned with the question whether diagnostic X-ray procedures might be the cause of an increased genetic risk. All studies have selected Down's syndrome (mongolism) as genetic indicator. They indiscriminately present the opinion of the respective author. Approximately one half of the studies conclude that radiation exposure will not influence the spontaneous incidence of Down's syndrome in diagnostics, the other half finds a positive relationship between frequent radiation exposure and the incidence of the syndrome. For various reasons, explained in detail, the results of the studies under discussion are suitable for forming hypotheses, but should not be viewed as providing evidence. (orig.) [de

  1. Comparative Analysis of the Pattern of Population Genetic Diversity in Three Indo-West Pacific Rhizophora Mangrove Species.

    Science.gov (United States)

    Yan, Yu-Bin; Duke, Norm C; Sun, Mei

    2016-01-01

    Rhizophora species are the most widely distributed mangrove trees in the Indo-West Pacific (IWP) region. Comparative studies of these species with shared life history traits can help identify evolutionary factors that have played most important roles in determining genetic diversity within and between populations in ocean-current dispersed mangrove tree species. We sampled 935 individuals from 54 natural populations for genotyping with 13 microsatellite markers to investigate the level of genetic variation, population structure, and gene flow on a broad geographic scale in Rhizophora apiculata, Rhizophora mucronata , and Rhizophora stylosa across the IWP region. In contrast to the pattern expected of long-lived woody plants with predominant wind-pollination, water-dispersed seeds and wide geographic range, genetic variation within populations was generally low in all the three species, especially in those peripheral populations from geographic range limits. Although the large water-buoyant propagules of Rhizophora have capacity for long distance dispersal, such events might be rare in reality, as reflected by the low level of gene flow and high genetic differentiation between most of population pairs within each species. Phylogeographic separation of Australian and Pacific island populations from SE Asian lineages previously revealed with DNA sequence data was still detectable in R. apiculata based on genetic distances, but this pattern of disjunction was not always evident in R. mucronata and R. stylosa , suggesting that fast-evolving molecular markers could be more suitable for detecting contemporary genetic structure but not deep evolutionary divergence caused by historical vicariance. Given that mangrove species generally have small effective population sizes, we conclude that genetic drift coupled with limited gene flow have played a dominant role in producing the current pattern of population genetic diversity in the IWP Rhizophora species, overshadowing the

  2. Cytogenetic techniques as biological indicator and dosimeter of radiation damage

    International Nuclear Information System (INIS)

    Hadjidekova, V.; Hristova, R.

    2006-01-01

    Full text: The cytogenetic methods are established techniques for bio monitoring and bio dosimetry of professionally and accidentally exposed to ionizing radiation subjects. They are applied to continue the evaluation of the physical dosimetry and to consider the individual radiosensitivity. The results of cytogenetic monitoring and dosimetry of radiation exposed subjects carried out during the last 5 years in laboratory of Radiation Genetics, NCRRP is reported. Laboratory of Radiation genetics performs cytogenetic monitoring of low dose radiation professionally or medically exposed subjects: workers in Kozloduy NPP, radioactive waste repository workers, X-rays diagnostically exposed patients, and radiotherapy exposed as well. Three cytogenetic indicators are applied as the most sensitive indicators for human radiation exposure: analysis of micronuclei (MN), chromosomal aberrations (CA) and stable translocations (FISH). The optimized methodology for application of different cytogenetic techniques for radiation estimation is discussed

  3. Effects of ionizing radiation on life

    International Nuclear Information System (INIS)

    Rausch, L.

    1982-01-01

    Radiobiology in the last years was able to find detailed explanations for the effects of ionizing radiation on living organisms. But it is still impossible to make exact statements concerning the damages by radiation. Even now, science has to content itself with probability data. Moreover no typical damages of ionizing radiation can be identified. Therefore, the risks of ionizing radiation can only be determined by comparison with the spontaneous rate of cancerous or genetic defects. The article describes the interaction of high-energy radiation with the molecules of the organism and their consequences for radiation protection. (orig.)

  4. Comparative evaluation of two different coloured-pupal strains of the Mediterranean Fruit Fly, Ceratitis Capitata (Wied.) and some biological effects of gamma radiation on both of them

    International Nuclear Information System (INIS)

    Shoman, A.A.; Abulyazid, I.

    2002-01-01

    Dark spontaneous mutant pupae were isolated from brown laboratory reared pupae of the Mediterranean Fruit Fly, Ceratitis Capitata (Wied). This mutant was used construct a genetic sexing strain (G.S.S.) based on pupal sorting. Obtained data showed that there were no clear biological differences between the brown pupa wild-type) and dark pupae (mutant). Fecundity, %pupation, pupal size, pupal weight, % adults emergence, sex ratio, male mating competitiveness and male insemination females mated with studied. However, the present hatch ability of eggs laid by normal females mated with normal males emerging from the dark pupae was significantly reduced, compared to that of the brown pupae. No significant differences regarding the effects of gamma radiation (90 Gy) on all biological aspects were observed in both strains

  5. Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay

    International Nuclear Information System (INIS)

    Praveen Kumar, M.K.; Shyama, S.K.; Sonaye, B.S.; Naik, U Roshini; Kadam, S.B.; Bipin, P.D.; D’costa, A.; Chaubey, R.C.

    2014-01-01

    Highlights: • Possible genotoxic effect of accidental exposure of aquatic fauna to γ radiation. • Relative sensitivity of bivalves to γ radiation is also analyzed using comet assay. • γ radiation induced significant genetic damage in both the species of bivalves. • P. malabarica and M. casta exhibited a similar level of sensitivity to γ radiation. • Comet assay may be used as a biomarker for the environmental biomonitoring. - Abstract: Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of ‘Comet assay’ for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in

  6. Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay

    Energy Technology Data Exchange (ETDEWEB)

    Praveen Kumar, M.K., E-mail: here.praveen@gmail.com [Department of Zoology, Goa University, Goa 403206 (India); Shyama, S.K., E-mail: skshyama@gmail.com [Department of Zoology, Goa University, Goa 403206 (India); Sonaye, B.S. [Department of Radiation Oncology, Goa Medical College, Goa (India); Naik, U Roshini; Kadam, S.B.; Bipin, P.D.; D’costa, A. [Department of Zoology, Goa University, Goa 403206 (India); Chaubey, R.C. [Radiation Biology and Health Science Division, Bhabha Atomic Research Centre, Mumbai (India)

    2014-05-01

    Highlights: • Possible genotoxic effect of accidental exposure of aquatic fauna to γ radiation. • Relative sensitivity of bivalves to γ radiation is also analyzed using comet assay. • γ radiation induced significant genetic damage in both the species of bivalves. • P. malabarica and M. casta exhibited a similar level of sensitivity to γ radiation. • Comet assay may be used as a biomarker for the environmental biomonitoring. - Abstract: Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of ‘Comet assay’ for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in

  7. Genetic consequences of the influence of ionizing radiation on humans

    International Nuclear Information System (INIS)

    Mosse, I.B.

    2011-01-01

    There is no direct evidence that exposure of parents to ionizing radiation leads to excess heritable disease in offspring. What is the difference between human and other species in which radiation induced mutations are easily registered? During evolution germ cell selection ex vivo has been changed to a selection in vivo and we cannot observe such selection of radiation damaged cells in human.

  8. Comparative researches concerning cleaning chosen construction materials surface layer using UV and IR laser radiation

    International Nuclear Information System (INIS)

    Napadlek, W.; Marczak, J.; Kubicki, J.; Szudrowicz, M.

    2002-01-01

    The paper presents comparative research studies of cleaning out of deposits and pollution disposals on different constructional materials like; steel, cast iron, aluminium, copper by using UV and IR laser radiation of wavelength λ =1.064 μm; λ = 0.532 μm; λ = 0.355 μm and λ = 0.266 μm and also impulse laser TEA CO 2 at radiation λ = 10.6 μm were used for the experiments. Achieved experimental results gave us basic information on parameters and conditions and application of each used radiation wavelength. Each kind of pollution and base material should be individually treated, selecting the length of wave and radiation energy density. Laser microtreatment allows for broad cleaning application of the surface of constructional materials as well as may be used in future during manufacturing processes as: preparation of surface for PVD technology, galvanotechnics, cleaning of the surface of machine parts etc. (author)

  9. The incidence of genetic disorders in children and young adults

    International Nuclear Information System (INIS)

    Anderson, T.W.; Baird, P.A.; Lowry, R.B.; Newcombe, H.B.

    1987-11-01

    Current estimates of the genetic risks from exposure to ionizing radiation are based on two kinds of data: a) incidence rates in humans for the genetic diseases that are believed to be present in the population due to mutations of natural origin, and b) radiation induced mutation rates. One necessary prerequisite before any possible increase in genetic load from mutagens can be estimated is baseline information on the magnitude of genetically-caused ill health already present in the population. The present study utilizes the data base of an ongoing population-based Registry with multiple sources of ascertainment to estimate the present population load from genetic disease. It was found that 4.9% of liveborn individuals below 25 can be expected to have genetic or partly genetic diseases. This was composed of single-gene disorders (autosomal dominant, autosomal recessive and X-linked recessive), chromosomal anomalies and multifactorial disorders (including those present at birth and those later in onset). Since previous studies have usually considered all congenital anomalies (ICD 740-759) as part of the genetic load, data are also presented separately for this category to facilitate comparison with earlier studies. These new data should represent a better estimate of the genetic load in the population than previous studies

  10. Some notes on radiation immunology

    International Nuclear Information System (INIS)

    Sado, Toshihiko

    1977-01-01

    Immunological movement related to radiation immunology were reviewed. Basic items about cell mechanism of immunological reaction were explained, and then, relationship between immunity and radiation was given an outline. As to radiation effects on immunological lymphatic system, radiosensitivity of lymphocytes and immunological reaction, radiation effects on T and B cells, and radiosensitivity of lymphatic system, especially thymus were mentioned, and furthermore, delayed effects of radiation on immunological system were described. Radiation effects on relationship between bone marrow transplantation and genesis of reticulum cell tumor and delayed effects of radiation on them were mentioned, and genetic resistance against hematopoietic cell transplantation and its radiosensitivity were also described. Relationship between carcinogenesis due to radiation and immunity, and a state of specific immunological in an individual non-responsiveness having cancer, were also referred to. (Kanao, N.)

  11. Genetic predisposition and implications for radioprotection

    Energy Technology Data Exchange (ETDEWEB)

    Streffer, Christian [University Clinics, Essen, Essen (Germany)

    2000-05-01

    Treatments of cancer patients with ionizing radiation have shown in some cases severe acute radiation effects after radiation doses which are very well tolerated by most patients. Skin fibroblasts of these patients studied after in vitro irradiation also showed a high radiosensitivity frequently. It was found that these effects are based on genetic predisposition which was usually inherited from their parents. During recent years quite a number of these syndromes have been described in humans and often the responsible genes have been characterized: Ataxia telangiectasia, Bloom's syndrome, Fanconi anemia, Li Fraumeni syndrome, Nevoid basal cell carcinoma syndrome, Neurofibromatosis, Nijmegen breakage syndrome, Retinoblastoma. In most cases it was found that the regulation processes of DNA repair processes and of the cell cycle for cell proliferation are disturbed. Frequently these processes cannot be separated from each other. Quite a number of these syndromes also show genomic instability which can also be induced by radiation exposures. These Phenomena have mainly been studied by determining the rate of chromosomal aberrations many cell generations after the exposure took place. Genomic instability apparently plays an important role for the development of stochastic late effects for which multistep events are necessary. This is especially for carcinogenesis the case. In mice it has been shown that radiation-induced genomic instability can be transmitted to the next mouse generation. In mouse models and also with radiotherapy patients it has been shown that genetic predisposition not only increases radiosensitivity with respect to cell survival and chromosomal damage but also to carcinogenesis. This has been observed cf. with p53-knock out mice and with children after radiotherapy cf. treatment of retinoblastoma. In the children with a genetic predisposition for retinoblastoma secondary tumours occurred to a much higher rate than in those children with

  12. Genetic predisposition and implications for radioprotection

    International Nuclear Information System (INIS)

    Streffer, Christian

    2000-01-01

    Treatments of cancer patients with ionizing radiation have shown in some cases severe acute radiation effects after radiation doses which are very well tolerated by most patients. Skin fibroblasts of these patients studied after in vitro irradiation also showed a high radiosensitivity frequently. It was found that these effects are based on genetic predisposition which was usually inherited from their parents. During recent years quite a number of these syndromes have been described in humans and often the responsible genes have been characterized: Ataxia telangiectasia, Bloom's syndrome, Fanconi anemia, Li Fraumeni syndrome, Nevoid basal cell carcinoma syndrome, Neurofibromatosis, Nijmegen breakage syndrome, Retinoblastoma. In most cases it was found that the regulation processes of DNA repair processes and of the cell cycle for cell proliferation are disturbed. Frequently these processes cannot be separated from each other. Quite a number of these syndromes also show genomic instability which can also be induced by radiation exposures. These Phenomena have mainly been studied by determining the rate of chromosomal aberrations many cell generations after the exposure took place. Genomic instability apparently plays an important role for the development of stochastic late effects for which multistep events are necessary. This is especially for carcinogenesis the case. In mice it has been shown that radiation-induced genomic instability can be transmitted to the next mouse generation. In mouse models and also with radiotherapy patients it has been shown that genetic predisposition not only increases radiosensitivity with respect to cell survival and chromosomal damage but also to carcinogenesis. This has been observed cf. with p53-knock out mice and with children after radiotherapy cf. treatment of retinoblastoma. In the children with a genetic predisposition for retinoblastoma secondary tumours occurred to a much higher rate than in those children with

  13. Comparative analysis of different approaches to the computation of long-wave radiation balance of water air systems

    International Nuclear Information System (INIS)

    Zhukovskii, K.; Nourani, Y.; Monte, L.

    1999-01-01

    In the present paper, the net long-wave radiation balance of the water-air environmental systems is analysed on the base of several semi-empirical approaches. Various theoretical models of infrared atmospheric radiation are reviewed. Factors, affecting their behavior are considered. Special attention is paid to physical conditions under which those models are applicable. Atmospheric and net infrared radiation fluxes are computed and compared under clear and cloudy sky. Results are presented in graphical form. Conclusions are made on the applicability of models considered for evaluating infrared radiation fluxes in environmental conditions of Central Italy. On the base of present analysis Anderson's model is chosen for future calculations of heat budget of lakes in Central Italy [it

  14. Radiation hormesis and its potential to manage radiation injuries

    International Nuclear Information System (INIS)

    Bala, Madhu; Mathew, Lazar

    2000-01-01

    The term radiation hormesis explains stimulatory or beneficial effects of low dose radiation exposure, which cannot be predicted by extrapolation of detrimental or lethal effects of high dose radiation exposure. Although beneficial effects of low doses of radiation were observed soon after discovery of x-rays and radioactivity, studies remained inconclusive until recently, due to (i) inadequate statistical planning of experiments conducted in early part of the 20th century; and (ii) poor dose monitoring. Recently (1980s onwards), large scale, systematic epidemiological and experimental studies with a number of diverse systems have demonstrated existence of radiation hormesis beyond doubt. It is pointed out that the hormetic effects of radiation have not been successfully exploited so far for human benefits, primarily because underlying molecular mechanisms are poorly understood. It is argued that with more and more studies, it is becoming evident that radiation hormesis is not merely physiological adaptation, but a genetically regulated phenomenon and involves de novo synthesis of proteins. Role of these proteins in induction of radiation hormesis is the current area of research in a number of world-renowned laboratories. The first part of this review elucidates the shifts in paradigms on radiation effects in the 20th century and the later portion presents a brief on underlying molecular mechanisms of radiation hormesis and their implications towards management of radiation injuries. (author)

  15. Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics

    Science.gov (United States)

    Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

    2015-12-01

    Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains.

  16. Genetic damage following nuclear war

    International Nuclear Information System (INIS)

    Oftedal, P.

    1984-01-01

    Genetic damage may be caused by ionizing radiation from the exploding bomb itself, or from radioactive nuclides released or formed in the explosion. Long-wave radiation in the heat flash and physical force do not contribute. Thus only a small fraction of the energy of the explosion - fission or fusion- can cause genetic damage. Neutron irradiation is generally found to be 5-20 times more efficient than gamma irradiation for the same absorbed dose. Fetuses and children are generally more radiosensitive than adults. Exposure of gonads during the proliferative stage of gonad growth may conceivably lead to a ''fluctuation test'' effect, so that a gonad may contain a sector of cells carrying identical mutations. A corresponding development may take place if the gonad stem cell population has been severely depleted by an acute exposure and recovers

  17. Radiobiological studies with the nematode Caenorhabditis elegans. Genetic and developmental effects of high LET radiation

    International Nuclear Information System (INIS)

    Nelson, G.A.; Schubert, W.W.; Marshall, T.M.

    1992-01-01

    The biological effects of heavy charged particle (HZE) radiation are of particular interest to travellers and planners for long-duration space flights where exposure levels represents a potential health hazard. The unique feature of HZE radiation is the structured pattern of its energy deposition in targets. There are many consequences of this feature to biological endpoints when compared with effects of ionizing photons. Dose vs response and dose-rate kinetics may be modified, DNA and cellular repair systems may be altered in their abilities to cope with damage, and the qualitative features of damage may be unique for different ions. The nematode Caenorhabditis elegans is being used to address these and related questions associated with exposure to radiation. HZE-induced mutation, chromosome aberration, cell inactivation and altered organogenesis are discussed along with plans for radiobiological experiments in space. (author)

  18. Radiation protection and radiation fear

    International Nuclear Information System (INIS)

    Czeizel, E.

    1982-01-01

    Some data are cited from Japanese statistics analyzing the genetic injuries stemming from the nuclear explosion in Hiroshima. It is shown that neither the number of the unsuccesful pregnancies nor the mortality of the born offsprings increased in those cases there the mother or the father had been exposed to 1-100 rad radiation. There was no significant difference in the chromosomal aberrations amoung the children of irradiated and control parents. (L.E.)

  19. Genetic and molecular analyses of UV radiation-induced mutations in the fem-3 gene of Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, P S; De Wilde, D; Dwarakanath, V N [Texas Christian Univ., Fort Worth, TX (United States). Dept. of Biology

    1995-06-01

    The utility of a new target gene (fem-3) is described for investigating the molecular nature of mutagenesis in the nematode Caenorhabditis elegans. As a principal attribute, this system allows for the selection, maintenance and molecular analysis of any type of mutation that disrupts the gene, including deletions. In this study, 86 mutant strains were isolated, of which 79 proved to have mutations in fem-3. Twenty of these originally tested as homozygous inviable. Homozygous inviability was expected, as Stewart and coworkers had previously observed that, unlike in other organisms, most UV radiation-induced mutations in C. elegans are chromosomal rearrangements of deficiencies (Mutat. Res 249, 37-54, 1991). However, additional data, including Southern blot analyses on 49 of the strains, indicated that most of the UV radiation-induced fem-3 mutations were not deficiencies, as originally inferred from their homozygous inviability. Instead, the lethals were most likely ``coincident mutations`` in linked, essential genes that were concomitantly induced. As such, they were lost owing to genetic recombination during stock maintenance. As in mammalian cells, yeast and bacteria, the frequency of coincident mutations was much higher than would be predicted by chance. (Author).

  20. Development of new techniques of using irradiation in the genetic improvement of warm season grasses and an assessment of the genetic and cytogenetic effects. Annual report, August 1, 1976--October 31, 1977

    International Nuclear Information System (INIS)

    Burton, G.W.; Hanna, W.W.

    1977-08-01

    New techniques of using irradiation in the genetic improvement of several warm season grasses are described. The economic value of radiation induced plant mutants and the genetic and cytogenetic effects of these treatments are discussed. Alterations in protein quality in pearl millet grain and improved varieties of Bermuda grass following radiation treatment are reported

  1. A treatment planning study comparing whole breast radiation therapy against conformal, IMRT and tomotherapy for accelerated partial breast irradiation

    International Nuclear Information System (INIS)

    Oliver, Mike; Chen, Jeff; Wong, Eugene; Van Dyk, Jake; Perera, Francisco

    2007-01-01

    Purpose and background: Conventional early breast cancer treatment consists of a lumpectomy followed by whole breast radiation therapy. Accelerated partial breast irradiation (APBI) is an investigational approach to post-lumpectomy radiation for early breast cancer. The purpose of this study is to compare four external beam APBI techniques, including tomotherapy, with conventional whole breast irradiation for their radiation conformity index, dose homogeneity index, and dose to organs at risk. Methods and materials: Small-field tangents, three-dimensional conformal radiation therapy, intensity-modulated radiation therapy and helical tomotherapy were compared for each of 15 patients (7 right, 8 left). One radiation conformity and two dose homogeneity indices were used to evaluate the dose to the target. The mean dose to organs at risk was also evaluated. Results: All proposed APBI techniques improved the conformity index significantly over whole breast tangents while maintaining dose homogeneity and without a significant increase in dose to organs at risk. Conclusion: The four-field IMRT plan produced the best dosimetric results; however this technique would require appropriate respiratory motion management. An alternative would be to use a four-field conformal technique that is less sensitive to the effects of respiratory motion

  2. Genetic effects of radiation in man

    International Nuclear Information System (INIS)

    Freire-Maia, N.

    1978-01-01

    Information obtained through three different surveys among Brazilian physicians is presented. Data have been classified according to survey, medical specialty, protection used and pregnancy order. Events under consideration are abortions, stillbirths, neo-natal mortality, infant-juvenile mortality, marbidity and sex ratio. A number of statistically sugnificant diferences have been found in the direction expected according to the radio-genetics theory and a few ones against it. Two of the surveys revealed an effect of the pregnancy order on abortions which was larger inthe exposed samples than in the control ones [pt

  3. Biological radiation effects

    International Nuclear Information System (INIS)

    Gomes, R.A.

    1976-01-01

    The stages of processes leading to radiation damage are studied, as well as, the direct and indirect mechanics of its production. The radiation effects on nucleic acid and protein macro moleculas are treated. The physical and chemical factors that modify radiosensibility are analysed, in particular the oxygen effects, the sensibilization by analogues of nitrogen bases, post-effects, chemical protection and inherent cell factors. Consideration is given to restoration processes by excision of injured fragments, the bloching of the excision restoration processes, the restoration of lesions caused by ionizing radiations and to the restoration by genetic recombination. Referring to somatic effects of radiation, the early ones and the acute syndrome of radiation are discussed. The difference of radiosensibility observed in mammalian cells and main observable alterations in tissues and organs are commented. Referring to delayed radiation effects, carcinogeneses, alterations of life span, effects on growth and development, as well as localized effects, are also discussed [pt

  4. The Genetic Relationship between Leishmania aethiopica and Leishmania tropica Revealed by Comparing Microsatellite Profiles.

    Science.gov (United States)

    Krayter, Lena; Schnur, Lionel F; Schönian, Gabriele

    2015-01-01

    Leishmania (Leishmania) aethiopica and L. (L.) tropica cause cutaneous leishmaniases and appear to be related. L. aethiopica is geographically restricted to Ethiopia and Kenya; L. tropica is widely dispersed from the Eastern Mediterranean, through the Middle East into eastern India and in north, east and south Africa. Their phylogenetic inter-relationship is only partially revealed. Some studies indicate a close relationship. Here, eight strains of L. aethiopica were characterized genetically and compared with 156 strains of L. tropica from most of the latter species' geographical range to discern the closeness. Twelve unlinked microsatellite markers previously used to genotype strains of L. tropica were successfully applied to the eight strains of L. aethiopica and their microsatellite profiles were compared to those of 156 strains of L. tropica from various geographical locations that were isolated from human cases of cutaneous and visceral leishmaniasis, hyraxes and sand fly vectors. All the microsatellite profiles were subjected to various analytical algorithms: Bayesian statistics, distance-based and factorial correspondence analysis, revealing: (i) the species L. aethiopica, though geographically restricted, is genetically very heterogeneous; (ii) the strains of L. aethiopica formed a distinct genetic cluster; and (iii) strains of L. aethiopica are closely related to strains of L. tropica and more so to the African ones, although, by factorial correspondence analysis, clearly separate from them. The successful application of the 12 microsatellite markers, originally considered species-specific for the species L. tropica, to strains of L. aethiopica confirmed the close relationship between these two species. The Bayesian and distance-based methods clustered the strains of L. aethiopica among African strains of L. tropica, while the factorial correspondence analysis indicated a clear separation between the two species. There was no correlation between

  5. The development of radiation protection

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1981-01-01

    The harm that might be caused by radiation exposure was recognised within months of Rontgen's discovery of X-rays, and recommendations for protection of patients and workers with radiation were formulated first in 1928. In the light of increasing radiobiological, genetic and human epidemiological evidence, it became clear that there might be no threshold, below which harmful effects did not occur. Recommendation and practice in radiation protection reflected this opinion from the early 1950's, and emphasised the consequent need for minimising exposures, quantifying risks and revising the dose limits appropriate for internal radiation of body organs. (author)

  6. Legislations for regulating the work with ionizing radiations in the arab counties a comparative analytical study

    International Nuclear Information System (INIS)

    El-Baroudy, M.M.

    2005-01-01

    In the framework of the developments taking place in nuclear sciences and technologies during the twentieth century and the resulting increase of useful applications of these technologies, the international efforts aiming at helping different countries to establish nuclear safety systems. This was also increased through the promulgation of legislations that render the practices, which could be accompanied with exposure to ionizing radiations, more safe within a firm legal system that is also backed by promulgating suitable executive regulations. Most Arab countries are keen to promulgate their legislations for regulating the work with ionizing radiations and protection against their dangers. Those legislations usually get their genesis and provisions from the international recommendations as well as from the general legal system of the country. The present work consists of four chapters. The first chapter deals with the definition of legislations for regulating the work with ionizing radiations. Chapter two discusses the international trend to promulgate legislations for protection against ionizing radiations. Chapter three includes an analytical comparative study on the legislations that regulates the work with ionizing radiations in the Arab countries. Finally, chapter four deals with the legislations for protection against ionizing radiations in the Arab Republic of Egypt

  7. Possible individual variation in susceptibility to radiation-induced genetic changes

    International Nuclear Information System (INIS)

    Gentner, N.E.; Walker, J.A.

    1990-01-01

    Several studies have shown variation between individuals in radiosensitivity. A person could have a high level of cytogenetic indicator because of high exposure or high susceptibility. To relate spontaneous cytogenetic end-points to dose it is advisable to have a measure of both the spontaneous level and of induced susceptibility. These end points need to be compared in irradiated persons who have developed cancer versus those who have not, as a guide to what end points are appropriate for susceptibility to radiogenic cancer. The use of inbred rodent strains may not be appropriate to derive specific locus mutation data relevant to the human situation, in which large differences in susceptibility appear to exist. Variability in response because of differential DNA repair capacity should be kept in mind when evaluating existing human data. For accident situations, using acute exposures for testing susceptibility may be appropriate, but to be relevant to low dose, low dose rate exposures, more use of protracted dose delivery in testing is recommended. There is a need for international collaborative study where these different tests are done on the same donors at the same time. It might now be prudent for radiation protection to take into account the occurrence of critical groups in the population on the basis of their increased radiation sensitivity. (12 refs., 3 figs.)

  8. Genetically significant dose assessments of occupationally exposed individuals involved in industrial and medical radiographic procedures in certain establishments in Nigeria

    International Nuclear Information System (INIS)

    Jibiri, N.N.; Oguntade, G. T.

    2007-01-01

    The main source of radiation doses received by humans from man-made sources of ionizing radiation in medicine and industry comes from X-rays. The genetic risks of ionizing radiation effects on an individual who is occupationally exposed largely depend on the magnitude of the radiation dose received, period of practice, work load and radio logical procedures involved. In this work, using the linear non-thresh old model, we have attempted to assess the level of genetic risk of occupationally exposed individuals in two medical and industrial establishments in Nigeria by estimating their genetically significant dose values. The estimation was based on continuous personnel radiation dose monitoring data for the individuals in each of the establishments over a three year period (1998-2001). The estimated genetically significant dose values in the years considered were 12 mSv for the medical, and 29 mSv for the industrial personnel. Appropriate radiation protection precautions should be taken by the personnel to adhere to standard operational practices in order to minimize the genetically significant dose resulting from radio logical practices

  9. Comparative radiation impact on biota and man in the area affected by the accident at the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    Fesenko, S.V.; Alexakhin, R.M.; Geras'kin, S.A.; Sanzharova, N.I.; Spirin, Ye.V.; Spiridonov, S.I.; Gontarenko, I.A.; Strand, P.

    2005-01-01

    A methodological approach for a comparative assessment of ionising radiation effects on man and non-human species, based on the use of Radiation Impact Factor (RIF) - ratios of actual exposure doses to biota species and man to critical dose is described. As such doses, radiation safety standards limiting radiation exposure of man and doses at which radiobiological effects in non-human species were not observed after the Chernobyl accident, were employed. For the study area within the 30 km ChNPP zone dose burdens to 10 reference biota groups and the population (with and without evacuation) and the corresponding RIFs were calculated. It has been found that in 1986 (early period after the accident) the emergency radiation standards for man do not guarantee adequate protection of the environment, some species of which could be affected more than man. In 1991 RIFs for man were considerably (by factor of 20.0-1.1 x 10 5 ) higher compared with those for selected non-human species. Thus, for the long term after the accident radiation safety standards for man are shown to ensure radiation safety for biota as well

  10. Comparative radiation impact on biota and man in the area affected by the accident at the Chernobyl nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Fesenko, S.V. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation) and International Atomic Energy Agency, Agency' s Laboratories, Seibersdorf A-2444 (Austria)]. E-mail: s.fesenko@iaea.org; Alexakhin, R.M. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Geras' kin, S.A. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Sanzharova, N.I. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Spirin, Ye.V. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Spiridonov, S.I. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Gontarenko, I.A. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Strand, P. [Norwegian Radiation Protection Authority, Oesteras (Norway)

    2005-07-01

    A methodological approach for a comparative assessment of ionising radiation effects on man and non-human species, based on the use of Radiation Impact Factor (RIF) - ratios of actual exposure doses to biota species and man to critical dose is described. As such doses, radiation safety standards limiting radiation exposure of man and doses at which radiobiological effects in non-human species were not observed after the Chernobyl accident, were employed. For the study area within the 30 km ChNPP zone dose burdens to 10 reference biota groups and the population (with and without evacuation) and the corresponding RIFs were calculated. It has been found that in 1986 (early period after the accident) the emergency radiation standards for man do not guarantee adequate protection of the environment, some species of which could be affected more than man. In 1991 RIFs for man were considerably (by factor of 20.0-1.1 x 10{sup 5}) higher compared with those for selected non-human species. Thus, for the long term after the accident radiation safety standards for man are shown to ensure radiation safety for biota as well.

  11. Mutation frequencies in male mice and the estimation of genetic hazards of radiation in men: (specific-locus mutations/dose-rate effect/doubling dose/risk estimation)

    International Nuclear Information System (INIS)

    Russell, W.L.; Kelly, E.M.

    1982-01-01

    Estimation of the genetic hazards of ionizing radiation in men is based largely on the frequency of transmitted specific-locus mutations induced in mouse spermatogonial stem cells at low radiation dose rates. The publication of new data on this subject has permitted a fresh review of all the information available. The data continue to show no discrepancy from the interpretation that, although mutation frequency decreases markedly as dose rate is decreased from 90 to 0.8 R/min (1 R = 2.6 X 10 -4 coulombs/kg) there seems to be no further change below 0.8 R/min over the range from that dose rate to 0.0007 R/min. Simple mathematical models are used to compute: (a) a maximum likelihood estimate of the induced mutation frequency at the low dose rates, and (b) a maximum likelihood estimate of the ratio of this to the mutation frequency at high dose rates in the range of 72 to 90 R/min. In the application of these results to the estimation of genetic hazards of radiation in man, the former value can be used to calculate a doubling dose - i.e., the dose of radiation that induces a mutation frequency equal to the spontaneous frequency. The doubling dose based on the low-dose-rate data compiled here is 110 R. The ratio of the mutation frequency at low dose rate to that at high dose rate is useful when it becomes necessary to extrapolate from experimental determinations, or from human data, at high dose rates to the expected risk at low dose rates. The ratio derived from the present analysis is 0.33

  12. Comparative Analysis of the Pattern of Population Genetic Diversity in Three Indo-West Pacific Rhizophora Mangrove Species

    Directory of Open Access Journals (Sweden)

    Yu-Bin Yan

    2016-09-01

    Full Text Available Rhizophora species are the most widely distributed mangrove trees in the Indo-West Pacific (IWP region. Comparative studies of these species with shared life history traits can help identify evolutionary factors that have played most important roles in determining genetic diversity within and between populations in ocean-current dispersed mangrove tree species. We sampled 935 individuals from 54 natural populations for genotyping with 13 microsatellite markers to investigate the level of genetic variation, population structure, and gene flow on a broad geographic scale in Rhizophora apiculata, R. mucronata, and R. stylosa across the IWP region. In contrast to the pattern expected of long-lived woody plants with predominant wind-pollination, water-dispersed seeds and wide geographic range, genetic variation within populations was generally low in all the three species, especially in those peripheral populations from geographic range limits. Although the large water-buoyant propagules of Rhizophora have capacity for long distance dispersal, such events might be rare in reality, as reflected by the low level of gene flow and high genetic differentiation between most of population pairs within each species. Phylogeographic separation of Australian and Pacific island populations from SE Asian lineages previously revealed with DNA sequence data was still detectable in R. apiculata based on genetic distances, but this pattern of disjunction was not always evident in R. mucronata and R. stylosa, suggesting that fast-evolving molecular markers could be more suitable for detecting contemporary genetic structure but not deep evolutionary divergence caused by historical vicariance. Given that mangrove species generally have small effective population sizes, we conclude that genetic drift coupled with limited gene flow have played a dominant role in producing the current pattern of population genetic diversity in the IWP Rhizophora species, overshadowing the

  13. Comparative risk assessment of radiation and other mutagenic agents

    International Nuclear Information System (INIS)

    Leenhouts, H.P.; Pruppers, M.J.M.; Wijngaard, E.; Sijsma, M.J.; Bouwens, B.T.; Chadwick, K.H.

    1990-04-01

    This is the final report of a contract of RIVM in the framework of the Radiation Protection Programme of the Commission of the European Communities. The aim of the project was to investigate the nature of the dose-effect relationship for radiobiological effects after different types of ionizing radiation and UV. The results support the idea that the linear-quadratic dose relationship for radiobiological effects does reflect a 2-hit or 2-event type of radiation effect. The track structure calculations of the linear term indicate that the DNA double-strand break could be the crucial lesion and that the 2 simultaneous events should occur close to each strand of the DNA molecule in a single track. The experimental data indicate that the quadratic term arises from the combination of 2 time independently induced events the role of which can be modified by repair but these data do not provide any information on the nature of the radiation induced lesions. (author). 8 refs.; 7 figs

  14. Genetic effects of nonionizing electromagnetic fields

    International Nuclear Information System (INIS)

    Lai, Henry

    2001-01-01

    Due to the increased use of electricity and wireless communication devices, there is a concern on whether exposure to nonionizing electromagnetic fields (50/60 Hz fields and radiofrequency radiation) can lead to harmful health effects, particularly, genetic effects and cancer development. This presentation will review recent research on genetic effects of power line frequency and radiofrequency electromagnetic fields. Even though the mechanism of interaction is still unknown, there is increasing evidence that these electromagnetic fields at low intensities can cause genetic damage in cells. There is also evidence suggesting that the effects are caused by oxidative stress. (author)

  15. A search for genetic effects of atomic bomb radiation on the growth and development of the F1 generation, 5

    International Nuclear Information System (INIS)

    Furusho, Toshiyuki; Otake, Masanori.

    1985-09-01

    In a search for possible genetic effects of atomic bomb radiation on the stature of the offspring of A-bomb survivors, a comparative study was made on elementary school pupils 6 to 11 years of age born to exposed and nonexposed parents in Hiroshima. The mean stature and variance for the offspring were determined, and the covariance and correlation were calculated in a comparison between either the values for one parent or the sum for both parents, and those for the offspring. Only a few of the differences in mean stature between exposed and nonexposed groups were statistically significant, but in all instances the difference tends to be larger in the exposed group than in the nonexposed group. Also, only a few of the differences in variance between the two groups were statistically significant, but the variance value of the exposed group was higher. Concerning the difference in correlation (Z transformation) between the two groups, only a very few were statistically significant, but the values of the exposed group were higher. A few of the regression coefficient of variance values were statistically significant and the signs of these regression coefficients were not always in agreement. (author)

  16. Ionising radiation. Part 2

    International Nuclear Information System (INIS)

    2000-01-01

    A brief tutorial on the health effects of ionising radiation is presented. The distinction between somatic and genetic health effects is explained. The two types of somatic health effects, i.e., acute and chronic effects, are discussed, as well as the concepts of ''deterministic'' and ''stochastic'' (also called ''probabilistic'') health effects. The possibility of cancer caused by DNA damage is discussed. The document ends with the definition of some key radiation terms

  17. Genetic and environmental interactions

    International Nuclear Information System (INIS)

    Strong, L.C.

    1977-01-01

    Cancer may result from a multistage process occurring over a long period of time. Presumably, initial and progressive stages of carcinogenesis may be modified by both genetic and environmental factors. Theoretically, genetic factors may alter susceptibility to the carcinogenic effects of an environmental agent at the initial exposure due to variation in metabolism of the carcinogen or variation in specific target cell response to the active carcinogen, or during the latent phase due to numerous factors that might increase the probability of tumor expression, including growth-promoting factors or immunodeficiency states. Observed genetic and environmental interactions in carcinogenesis include an association between genetically determined inducibility of aryl hydrocarbon hydroxylase and smoking-related cancers, familial susceptibility to certain environmental carcinogens, an association between hereditary disorders of mutagenesis and carcinogenesis, and enhancement of tissue-specific, dominantly inherited tumor predisposition by radiation. Multiple primary tumors occur frequently in genetically predisposed individuals. Specific markers for susceptibility must be sought in order that high-risk individuals be identified and appropriate measures taken for early cancer detection or prevention. Study of the nature of the genetically determined susceptibility and interactions with environmental agents may be revealing in the understanding of carcinogenesis in general

  18. Radiation-Related New Primary Solid Cancers in the Childhood Cancer Survivor Study: Comparative Radiation Dose Response and Modification of Treatment Effects

    International Nuclear Information System (INIS)

    Inskip, Peter D.; Sigurdson, Alice J.; Veiga, Lene; Bhatti, Parveen; Ronckers, Cécile; Rajaraman, Preetha; Boukheris, Houda; Stovall, Marilyn; Smith, Susan; Hammond, Sue; Henderson, Tara O.

    2016-01-01

    Objectives: The majority of childhood cancer patients now achieve long-term survival, but the treatments that cured their malignancy often put them at risk of adverse health outcomes years later. New cancers are among the most serious of these late effects. The aims of this review are to compare and contrast radiation dose–response relationships for new solid cancers in a large cohort of childhood cancer survivors and to discuss interactions among treatment and host factors. Methods: This review is based on previously published site-specific analyses for subsequent primary cancers of the brain, breast, thyroid gland, bone and soft tissue, salivary glands, and skin among 12,268 5-year childhood cancer survivors in the Childhood Cancer Survivor Study. Analyses included tumor site–specific, individual radiation dose reconstruction based on radiation therapy records. Radiation-related second cancer risks were estimated using conditional logistic or Poisson regression models for excess relative risk (ERR). Results: Linear dose–response relationships over a wide range of radiation dose (0-50 Gy) were seen for all cancer sites except the thyroid gland. The steepest slopes occurred for sarcoma, meningioma, and nonmelanoma skin cancer (ERR/Gy > 1.00), with glioma and cancers of the breast and salivary glands forming a second group (ERR/Gy = 0.27-0.36). The relative risk for thyroid cancer increased up to 15-20 Gy and then decreased with increasing dose. The risk of thyroid cancer also was positively associated with chemotherapy, but the chemotherapy effect was not seen among those who also received very high doses of radiation to the thyroid. The excess risk of radiation-related breast cancer was sharply reduced among women who received 5 Gy or more to the ovaries. Conclusions: The results suggest that the effect of high-dose irradiation is consistent with a linear dose–response for most organs, but they also reveal important organ-specific and host

  19. Radiation-Related New Primary Solid Cancers in the Childhood Cancer Survivor Study: Comparative Radiation Dose Response and Modification of Treatment Effects

    Energy Technology Data Exchange (ETDEWEB)

    Inskip, Peter D., E-mail: inskippeter@gmail.com [Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States); Sigurdson, Alice J.; Veiga, Lene [Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States); Bhatti, Parveen [Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States); Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington (United States); Ronckers, Cécile [Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States); Department of Pediatric Oncology, Emma Children' s Hospital/Academic Medical Center, Amsterdam (Netherlands); Rajaraman, Preetha [Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States); Boukheris, Houda [Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States); The University of Oran School of Medicine (Algeria); Stovall, Marilyn; Smith, Susan [Department of Radiation Physics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas (United States); Hammond, Sue [Department of Laboratory Medicine and Pathology, Children' s Hospital and Ohio State University College of Medicine, Columbus, Ohio (United States); Henderson, Tara O. [University of Chicago Department of Pediatrics, Section of Hematology, Oncology and Stem Cell Transplantation, Chicago, Illinois (United States); and others

    2016-03-15

    Objectives: The majority of childhood cancer patients now achieve long-term survival, but the treatments that cured their malignancy often put them at risk of adverse health outcomes years later. New cancers are among the most serious of these late effects. The aims of this review are to compare and contrast radiation dose–response relationships for new solid cancers in a large cohort of childhood cancer survivors and to discuss interactions among treatment and host factors. Methods: This review is based on previously published site-specific analyses for subsequent primary cancers of the brain, breast, thyroid gland, bone and soft tissue, salivary glands, and skin among 12,268 5-year childhood cancer survivors in the Childhood Cancer Survivor Study. Analyses included tumor site–specific, individual radiation dose reconstruction based on radiation therapy records. Radiation-related second cancer risks were estimated using conditional logistic or Poisson regression models for excess relative risk (ERR). Results: Linear dose–response relationships over a wide range of radiation dose (0-50 Gy) were seen for all cancer sites except the thyroid gland. The steepest slopes occurred for sarcoma, meningioma, and nonmelanoma skin cancer (ERR/Gy > 1.00), with glioma and cancers of the breast and salivary glands forming a second group (ERR/Gy = 0.27-0.36). The relative risk for thyroid cancer increased up to 15-20 Gy and then decreased with increasing dose. The risk of thyroid cancer also was positively associated with chemotherapy, but the chemotherapy effect was not seen among those who also received very high doses of radiation to the thyroid. The excess risk of radiation-related breast cancer was sharply reduced among women who received 5 Gy or more to the ovaries. Conclusions: The results suggest that the effect of high-dose irradiation is consistent with a linear dose–response for most organs, but they also reveal important organ-specific and host

  20. Big Data and Comparative Effectiveness Research in Radiation Oncology: Synergy and Accelerated Discovery

    Science.gov (United States)

    Trifiletti, Daniel M.; Showalter, Timothy N.

    2015-01-01

    Several advances in large data set collection and processing have the potential to provide a wave of new insights and improvements in the use of radiation therapy for cancer treatment. The era of electronic health records, genomics, and improving information technology resources creates the opportunity to leverage these developments to create a learning healthcare system that can rapidly deliver informative clinical evidence. By merging concepts from comparative effectiveness research with the tools and analytic approaches of “big data,” it is hoped that this union will accelerate discovery, improve evidence for decision making, and increase the availability of highly relevant, personalized information. This combination offers the potential to provide data and analysis that can be leveraged for ultra-personalized medicine and high-quality, cutting-edge radiation therapy. PMID:26697409

  1. Radiation effects on the human organs, app. A

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The appendix is subdivided into eleven chapters dealing with radiation effcts on organisms and comprising the following subjects: biological effects of ionizing radiations (dose, LET, RBE, formation of radicals, age and sex, cell types, biological repair), recommendations and protective measures for somatic risks, genetic risks, experimental models and dose-effect relationships, and internal radiation. The groups conclusions are given

  2. Combined genetic effects of chemicals and radiation

    International Nuclear Information System (INIS)

    Kada, T.; Inoue, T.; Yokoiyama, A.; Russel, L.B.

    1979-01-01

    Interactions of chemicals and radiation are complex and there may exist other unexpected patterns that are not mentioned. We show some examples. Photodynamic mutation induction by fluorescein dyes and Radiosensitization with iodine compounds are classified as Interactions of chemicals and radiation outside of the cell. On the other hand, the Antimutagenic effects of cobaltous chloride is concerned with events taking place in cells that had already been exposed to a mutagenic agent. It is likely that the action of a mutagenic agent is not direct and that cellular functions, such as mutators or repair systems, are involved in the mutagenesis initiated by the agent. Such cellular functions can be affected by a second agent. In sexually reproducing organisms, the two agents can also act on separate cells (male and female germcells) which subsequently fuse. Interaction effects of all types will be useful in future research in shedding light on the main pathways of mutagenesis

  3. A Population-Based Comparative Effectiveness Study of Radiation Therapy Techniques in Stage III Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Jeremy P. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Murphy, James D. [Department of Radiation Medicine and Applied Science, University of California– San Diego, Moores Cancer Center, La Jolla, California (United States); Hanlon, Alexandra L. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); University of Pennsylvania School of Nursing, Philadelphia, Pennsylvania (United States); Le, Quynh-Thu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Loo, Billy W., E-mail: BWLoo@Stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Diehn, Maximilian, E-mail: diehn@Stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California (United States)

    2014-03-15

    Purpose: Concerns have been raised about the potential for worse treatment outcomes because of dosimetric inaccuracies related to tumor motion and increased toxicity caused by the spread of low-dose radiation to normal tissues in patients with locally advanced non-small cell lung cancer (NSCLC) treated with intensity modulated radiation therapy (IMRT). We therefore performed a population-based comparative effectiveness analysis of IMRT, conventional 3-dimensional conformal radiation therapy (3D-CRT), and 2-dimensional radiation therapy (2D-RT) in stage III NSCLC. Methods and Materials: We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare database to identify a cohort of patients diagnosed with stage III NSCLC from 2002 to 2009 treated with IMRT, 3D-CRT, or 2D-RT. Using Cox regression and propensity score matching, we compared survival and toxicities of these treatments. Results: The proportion of patients treated with IMRT increased from 2% in 2002 to 25% in 2009, and the use of 2D-RT decreased from 32% to 3%. In univariate analysis, IMRT was associated with improved overall survival (OS) (hazard ratio [HR] 0.90, P=.02) and cancer-specific survival (CSS) (HR 0.89, P=.02). After controlling for confounders, IMRT was associated with similar OS (HR 0.94, P=.23) and CSS (HR 0.94, P=.28) compared with 3D-CRT. Both techniques had superior OS compared with 2D-RT. IMRT was associated with similar toxicity risks on multivariate analysis compared with 3D-CRT. Propensity score matched model results were similar to those from adjusted models. Conclusions: In this population-based analysis, IMRT for stage III NSCLC was associated with similar OS and CSS and maintained similar toxicity risks compared with 3D-CRT.

  4. Comparative analysis of genetic diversity among Chinese watermelon germplasmsusing SSR and SRAP markers, and implications for future genetic improvement

    OpenAIRE

    WANG, PANGQIAO; LI, QIONG; Hu, Jianbin; SU, YAN

    2015-01-01

    The genetic diversity of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] in China, the world's largest producer of watermelon fruits, has not been examined. Two molecular markers, sequence-related amplified polymorphism (SRAP) and simple sequence repeat (SSR), were used to investigate the genetic variation and genetic relationship among 54 Chinese watermelon accessions, as well as 7 accessions from Africa, the United States, and Japan. SRAP assay generated 312 bands, ...

  5. Advances in genetics and immunology: the importance of basic research to prevention of occupational diseases

    International Nuclear Information System (INIS)

    Omenn, G.S.

    1984-01-01

    Differences among workers in susceptibility to workplace exposures to environmental agents such as metals, ultraviolet radiation, and x-radiation are discussed. The distinction is made between the need for (1) monitoring for effects on the genetic material (genetic toxicology) and (2) screening for predisposing inherited traits (eco-genetics). Genetically-determined differences in susceptibility are discussed in relation to mechanisms of metabolism and of target sites. While there is not enough evidence to support routine genetic screening at this time there is common agreement that several promising areas for research on potential genetic predispositions warrant careful study. There is also reassuring evidence that productive relationships for research can be established among unions, management, and universities. 56 references, 3 figures, 7 tables

  6. [Comparative rheoencephalographic and convective radiation encephalic thermometric studies].

    Science.gov (United States)

    Vaĭsfel'd, D N; Korobov, S A; Petrov, A P

    1996-01-01

    It is for the first time that thermoassimetry of heart flows of brain right and left hemispheres presenting as predominance of radiative-convective heat radiation from the left has been revealed, the thermoassimetry gradient being rostral-caudal. Disclosed in cerebral hemispheres was complimentarity of energetic processes: the right hemisphere secures the background energy state, the left one functions in ensuring the discrete adaptive thermoenergy reactions. The thermoassimetry revealed may be the basis of other functional asymmetries of the brain. There was no parallelism between the studied parameters of circulation and heat flow.

  7. [Effects of electromagnetic radiation on health and immune function of operators].

    Science.gov (United States)

    Li, Yan-zhong; Chen, Shao-hua; Zhao, Ke-fu; Gui, Yun; Fang, Si-xin; Xu, Ying; Ma, Zi-jian

    2013-08-01

    To investigate the effects of electromagnetic radiation on the physiological indices and immune function of operators. The general conditions and electromagnetic radiation awareness rate of 205 operators under electromagnetic radiation were evaluated using a self-designed questionnaire. Physical examination, electrocardiography, and routine urine test were performed in these operators. Peripheral blood was collected from the operators under electromagnetic radiation for blood cell counting and biochemical testing, and their peripheral blood lymphocytes were cultured for determination of chromosomal aberrant frequency and micronucleus frequency. The data from these operators (exposure group) were compared with those of 95 ordinary individuals (control group). The chief complaint of giddiness, tiredness, dizziness, and amnesia showed significant differences between the exposure group and control group (P electromagnetic radiation damage was significantly higher in the exposure group than in the control group. The difference in bradycardia was significant between the two groups (P Electromagnetic radiation may lead to the changes in physiological indices, genetic effects, and immune function and affect the health and immune function in operators. The adverse effects are increased as the working years increase. So it is important to strengthen occupational protection of operators under electromagnetic radiation.

  8. Proceedings of the symposium on molecular biology and radiation protection

    International Nuclear Information System (INIS)

    Marko, A.M.

    1996-02-01

    The symposium on molecular biology and radiation protection was organized in sessions with the following titles: Radiation protection and the human genome; Molecular changes in DNA induced by radiation; Incidence of genetic changes - pre-existing, spontaneous and radiation-induced; Research directions and ethical implications. The ten papers in the symposium have been abstracted individually

  9. Proceedings of the symposium on molecular biology and radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Marko, A M [Atomic Energy Control Board, Ottawa, ON (Canada). Advisory Committee on Radiological Protection; Myers, D K; Atchison, R J [Atomic Energy Control Board, Ottawa, ON (Canada). Advisory Committee on Radiological Protection. Secretariat; Gentner, N E [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

    1996-02-01

    The symposium on molecular biology and radiation protection was organized in sessions with the following titles: Radiation protection and the human genome; Molecular changes in DNA induced by radiation; Incidence of genetic changes - pre-existing, spontaneous and radiation-induced; Research directions and ethical implications. The ten papers in the symposium have been abstracted individually.

  10. Sound quality prediction for engine-radiated noise

    Science.gov (United States)

    Liu, Hai; Zhang, Junhong; Guo, Peng; Bi, Fengrong; Yu, Hanzhengnan; Ni, Guangjian

    2015-05-01

    Diesel engine-radiated noise quality prediction is an important topic because engine noise has a significant impact on the overall vehicle noise. Sound quality prediction is based on subjective and objective evaluation of engine noise. The integrated satisfaction index (ISI) is proposed as a criterion for differentiate noise quality in the subjective evaluation, and five psychoacoustic parameters are selected for characterizing and analyzing the noise quality of the diesel engine objectively. The combination of support vector machines (SVM) and genetic algorithm (GA) is proposed in order to establish a model for predicting the diesel engine-radiated noise quality for all operation conditions. The performance of the GA-SVM model is compared with the BP neural network model, and the results show that the mean relative error of the GA-SVM model is smaller than the BP neural network model. The importance rank of the sound quality metrics to the ISI is indicated by the non-parametric correlation analysis. This study suggests that the GA-SVM model is very useful for accurately predicting the diesel engine-radiated noise quality.

  11. BRCA mutations in women from Belarus exposed to radiation from Chernobyl compared to controls

    International Nuclear Information System (INIS)

    Melnov, S.B.; Nadyrov, E.; Modugno, F.; Foley, T.; Murphy, P.; Putyrski, L.

    2009-01-01

    Full text: There are several reports of studies that suggest a causal association between exposure to ionizing radiation and the subsequent development of breast cancer. Since the Chernobyl accident in 1986, there has been a dramatic increase in thyroid cancer after radiation exposure, especially among those who were exposed as young children and living in the areas with the greatest contamination. One early report found that women exposed to radiation from Chernobyl had a slight, but significant increase in the incidence of breast cancer. No other data are reported about additional risks for the development of breast cancer in this population. With funding from a NIH R03 grant application and the Child Health International Foundation, we are investigating the molecular epidemiology of breast cancer in Belarusian women exposed at ages < 40 years to high radiation doses from the Chernobyl accident compared to controls for the common Eastern European BRCA 1/2 mutations. As occurred 20+ years after exposure of Japanese women exposed to radiation fallout from atomic bombs in 1945, we expect to find a sustained increase in breast cancer for the coming decade and longer. We accomplished nearly all of the following objectives in the evaluation of Belarusian women with breast cancer and controls who were exposed to sustained high doses of ionizing radiation in 1986. When our US collaborators visited the Republic of Belarus, they (a) met with Belarusian consultants, co-investigators, other health care professionals and administrators and developed a formal collaboration to study breast cancer, BRCA mutations and radiation exposure; (b) recruited Belarusian cancer epidemiologists, Chernobyl radiation dosimetrists, and cancer registry/database management personnel; (c) began a collaboration with the Director of Breast Cancer Surgery for the Republic of Belarus and met several breast cancer specialists in surgery and oncology under his direction; and (d) met medical directors

  12. Evaluation of Resveratrol as Radioprotector Against Radiation-Induced Genetic Damage in Mice

    International Nuclear Information System (INIS)

    Hasan, N.H.A.; El-Dawy, H.A.; Salah, A.E.

    2014-01-01

    The objective of this study is to give more information about the role of resveratrol as radioprotector. The radioprotective effect of resveratrol against radiation-induced chromosomal aberrations was evaluated in mice by intraperitoneal administration of resveratrol (50 mg/kg body weight) 30 minute priror to whole body gamma irradiation (4 Gy).The data obtained from the present study indicated that resveratrol induced significant decline in the total chromosomal aberrations when injected before gamma irradiation as compared with the gamma irradiated group, but still significantly higher than that of control group.

  13. Radiation induced DNA damage and repair in mutagenesis

    International Nuclear Information System (INIS)

    Strniste, G.F.; Chen, D.J.; Okinaka, R.T.

    1987-01-01

    The central theme in cellular radiobiological research has been the mechanisms of radiation action and the physiological response of cells to this action. Considerable effort has been directed toward the characterization of radiation-induced DNA damage and the correlation of this damage to cellular genetic change that is expressed as mutation or initiating events leading to cellular transformation and ultimately carcinogenesis. In addition, there has been a significant advancement in their understanding of the role of DNA repair in the process of mutation leading to genetic change in cells. There is extensive literature concerning studies that address radiation action in both procaryotic and eucaryotic systems. This brief report will make no attempt to summarize this voluminous data but will focus on recent results from their laboratory of experiments in which they have examined, at both the cellular and molecular levels, the process of ionizing radiation-induced mutagenesis in cultured human cells

  14. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    There are evidences to show that response to ionizing radiations have genetic influence. To investigate this further, reciprocal F1 hybrids were genereted by crossbreeding the radiation-susceptible BALB/c mouse strain with resistant C57BL/6 in a sex-specific manner (BALB/c♂×C57BL/6♀ = B6BcF1; C57BL/6♂× BALB/c♀ ...

  15. Low-level radiation effects: a fact book

    International Nuclear Information System (INIS)

    Brill, A.B.; Adelstein, S.J.; Saenger, E.L.; Webster, E.W.

    1982-01-01

    Low Level Raidation Effects: A Fact Book, prepared by the Society of Nuclear Medicine Subcommittee on the Risks of Low-Level Ionizing Radiation, attempts to examine the health effects of small doses of radiation. For immediate questions, this work provides a well-organized brief summary of recent radiologic data from refereed scientific literature and from the publications of advisory groups such as the National Council of Radiation Protection and Measurement (NCRP), the International Commission on Radiological Protection (ICRP), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), and the National Academy of Sciences (NAS). Since it consists almost entirely of tables and graphs from the above-mentioned sources along with summary paragraphs, the Fact Book is very useful in the preparation of lectures. The book is divided into seven sections. Chapter One, Glossary, Units and Conversion Factors, is useful because nearly all data given in the rest of the book is in conventional units and should be converted to SI units for future technical audiences. Chapter 2, Radiobiology, covers the fundamental principles of the field. Chapter 3, Radiation Doses, can be used to help an audience appreciate the relative magnitudes of radiation exposures they may read about or encounter. Chapter 4, Late Somatic Effects of Low Doses of Ionizing Radiation, gives data concerning cancer induction and embryonic effects, and Chapter 5 provides data on genetic effects Chapter 6, Risks, Statistical Facts and Public Perception can be used to compare the risks of radiation exposure with more commonly encountered risks

  16. Dynamic CT for Parathyroid Adenoma Detection: How Does Radiation Dose Compare With Nuclear Medicine?

    Science.gov (United States)

    Czarnecki, Caroline A; Einsiedel, Paul F; Phal, Pramit M; Miller, Julie A; Lichtenstein, Meir; Stella, Damien L

    2018-05-01

    Dynamic CT is increasingly used for preoperative localization of parathyroid adenomas, but concerns remain about the radiation effective dose of CT compared with that of 99m Tc-sestamibi scintigraphy. The purpose of this study was to compare the radiation dose delivered by three-phase dynamic CT with that delivered by 99m Tc-sestamibi SPECT/CT performed in accordance with our current protocols and to assess the possible reduction in effective dose achieved by decreasing the scan length (i.e., z-axis) of two phases of the dynamic CT protocol. The effective dose of a 99m Tc-sestamibi nuclear medicine parathyroid study performed with and without coregistration CT was calculated and compared with the effective dose of our current three-phase dynamic CT protocol as well as a proposed protocol involving CT with reduced scan length. The median effective dose for a 99m Tc-sestamibi nuclear medicine study was 5.6 mSv. This increased to 12.4 mSv with the addition of coregistration CT, which is higher than the median effective dose of 9.3 mSv associated with the dynamic CT protocol. Reducing the scan length of two phases in the dynamic CT protocol could reduce the median effective dose to 6.1 mSv, which would be similar to that of the dose from the 99m Tc-sestamibi study alone. Dynamic CT used for the detection of parathyroid adenoma can deliver a lower radiation dose than 99m Tc-sestamibi SPECT/CT. It may be possible to reduce the dose further by decreasing the scan length of two of the phases, although whether this has an impact on accuracy of the localization needs further investigation.

  17. Radiation induced mutant crop varieties: accomplishment and societal deployment

    International Nuclear Information System (INIS)

    D'Souza, S.F.

    2009-01-01

    One of the peaceful applications of atomic energy is in the field of agriculture. It finds application in crop improvement, crop nutrition, crop protection and food preservation. Genetic improvement of crop plants is a continuous endeavor. Success of a crop improvement programme depends on the availability of large genetic variability, which a plant breeder can combine to generate new varieties. In nature, occurrence of natural variability in the form of spontaneous mutations is extremely low (roughly 10 -6 ), which can be enhanced to several fold (approximately 10 -3 ) by using ionizing radiations or chemical mutagens. Radiation induced genetic variability in crop plants is a valuable resource from which plant breeder can select and combine different desired characteristics to produce better crop varieties. Crop improvement programmes at Bhabha Atomic Research Centre (BARC) envisage radiation based induced mutagenesis along with recombination breeding in country's important cereals (rice and wheat), oilseeds (groundnut, mustard, soybean and sunflower), grain legumes (blackgram, mungbean, pigeonpea and cowpea), banana and sugarcane

  18. The large-scale blast score ratio (LS-BSR pipeline: a method to rapidly compare genetic content between bacterial genomes

    Directory of Open Access Journals (Sweden)

    Jason W. Sahl

    2014-04-01

    Full Text Available Background. As whole genome sequence data from bacterial isolates becomes cheaper to generate, computational methods are needed to correlate sequence data with biological observations. Here we present the large-scale BLAST score ratio (LS-BSR pipeline, which rapidly compares the genetic content of hundreds to thousands of bacterial genomes, and returns a matrix that describes the relatedness of all coding sequences (CDSs in all genomes surveyed. This matrix can be easily parsed in order to identify genetic relationships between bacterial genomes. Although pipelines have been published that group peptides by sequence similarity, no other software performs the rapid, large-scale, full-genome comparative analyses carried out by LS-BSR.Results. To demonstrate the utility of the method, the LS-BSR pipeline was tested on 96 Escherichia coli and Shigella genomes; the pipeline ran in 163 min using 16 processors, which is a greater than 7-fold speedup compared to using a single processor. The BSR values for each CDS, which indicate a relative level of relatedness, were then mapped to each genome on an independent core genome single nucleotide polymorphism (SNP based phylogeny. Comparisons were then used to identify clade specific CDS markers and validate the LS-BSR pipeline based on molecular markers that delineate between classical E. coli pathogenic variant (pathovar designations. Scalability tests demonstrated that the LS-BSR pipeline can process 1,000 E. coli genomes in 27–57 h, depending upon the alignment method, using 16 processors.Conclusions. LS-BSR is an open-source, parallel implementation of the BSR algorithm, enabling rapid comparison of the genetic content of large numbers of genomes. The results of the pipeline can be used to identify specific markers between user-defined phylogenetic groups, and to identify the loss and/or acquisition of genetic information between bacterial isolates. Taxa-specific genetic markers can then be translated

  19. Genetics of human sensitivity to ultraviolet radiation

    Science.gov (United States)

    Cleaver, James E.

    1994-07-01

    the major human health effects of solar and artificial UV light occur from the UVB and UVC wavelength ranges and involve a variety of short-term and long-term deleterious changes to the skin and eyes. the more important initial damage to cellular macromolecules involves dimerization of adjacent pyrimidines in DNA to produce cyclobutane pyrimidine dimes, (6-4) pyrimidine- pyrimidone, and (6-4) dewar photoproducts. these photoproducts can be repaired by a genetically regulated enzyme system (nucleotide excision repair) which removes oligonucleotides 29-30 nucleotides long that contain the photoproducts, and synthesizes replacement patches. At least a dozen gene products are involved in the process of recognizing photoproducts in DNA, altering local DNA helicity and cleaving the polynucleotide chain at defined positions either side of a photoproduct. Hereditary mutations in many of these genes are recognized in the human genetic disorders xeroderma pigmentosum (XP), Cockayne syndrome (CS), and trichothiodystrophy (TTD). Several of the gene products have other functions involving the regulation of gene transcription which accounts for the complex clinical presentation of repair deficient diseases that involve sensitivity of the skin and eyes to UV light, increased solar carcinogenesis (in XP), demyelination, and ganglial calcification (in CS), hair abnormalities (in TTD), and developmental and neurological abnormalities

  20. Nevoid basal cell carcinoma syndrome. Profile of genetic and environmental factors in oncogenesis

    International Nuclear Information System (INIS)

    Howell, J.B.

    1984-01-01

    Nevoid basal cell carcinomas (NBCCs) are a prototype of a genetic form of basal cell carcinoma. These basal cell cancers, rather than being caused by genetic factors alone, are most likely the product of genetic and environmental factors. The NBCC syndrome provides a model for studying tumors induced by ionizing radiation and for viewing carcinogenesis as a multistage process explainable by a minimum of two steps. The interaction of genetic and environmental factors in producing tumors to which an individual is predisposed can be studied in patients with the NBCC syndrome and childhood medulloblastoma that was treated by radiation therapy. Individuals with the NBCC syndrome represent a special subgroup with a hereditary predisposition to basal cell carcinoma in whom ionizing radiation may supply the subsequent mutation necessary for tumor development. The genetically altered epidermis underlying the palm and sole pits found in patients with the syndrome represents basal cell carcinoma in situ from which basal cell carcinomas develop, albeit infrequently. The restrained biologic behavior of most of these tumors contrasts with the usual destructive behavior of the NBCCs of the head and neck in the same patient

  1. Pregnancy and Radiation

    Directory of Open Access Journals (Sweden)

    Hatice Bilge

    2010-10-01

    Full Text Available Many women per year expose ionizing radiation during pregnancy for medical reason (diagnostic or treatment. Ionizing radiation is known to cause harm on the human embryo and fetus. Potential adverse outcomes related to radiation exposure during pregnancy include teratogenicity, genetic damage, intrauterine death and increased risk of malignancy. Most diagnostic radiation procedures will lead to a fetal absorbed dose of less than 1 mGy (0.1 rad for imaging not involving abdomen / pelvis, less than 50 mGy (5 rad for involving abdomen / pelvis and less than 10 mGy (1 rad for direct or nuclear medicine imaging. When a pregnant patient requires radiation therapy, the physician should consider fetal sensitivity to radiation in early gestational age and the expected dose of radiation and should then calculate the risk to the fetus versus the benefits to the mother. It is safest to administer radiotherapy during or after the 25th week of gestation. The use of radiation for diagnostic imaging or treatment in the pregnant woman is associated with a high level of anxiety for woman, her family and her doctors. This article reviews the biological effects of radiation on the fetus. Recommendations to take in to account when considering the safety of the fetus during a procedure are presented.

  2. Biological effects of alpha radiation on a human population

    International Nuclear Information System (INIS)

    Thorleifson, E.M.; Marro, L.; Tracy, B.L.; Wilkinson, D.; Segura, T.M.; Prud'homme-Lalonde, L.; Leach, K.; Ford, B.N.

    2003-01-01

    Full text: In the environment, natural and man-made sources of radioactive material can become integrated into the food chain. Polonium-210 is a significant source of radiation exposure to caribou and to northern human populations who are dependent on caribou for a major portion of their meat supply. Previous work has shown that humans consuming caribou meat containing measurable quantities of polonium-210 can incorporate a substantial fraction of the radionuclide (Thomas et. al.). Conventional chromosome aberration analysis of blood samples collected from 40 individuals who routinely consumed caribou meat was performed to measure genetic damage from the ingested radioactive material. At least 500 metaphase spreads were analysed for each of 39 individuals. Radiation-specific chromosomal aberrations such as dicentrics and rings were scored and their frequencies were compared to the range of aberrations observed in non-caribou consuming populations. This study was designed to address the possible impact of environmental polonium-210 on background radiation health effects in humans

  3. Evaluation of gamma radiation induced genetic damage in the fish Cyprinus carpio using comet assay

    International Nuclear Information System (INIS)

    Praveen Kumar, M.K.; Shyama, S.K.; Bhagat, S.S.; Chaubey, R.C.

    2013-01-01

    Radionuclides released from various sources including the industries, as well as, accidental release during a nuclear disaster can contaminate inland water bodies. Suitable bio-monitoring methods/biomarkers are the need of the day to assess the impact of high/low levels of radiation exposure in aquatic environment. Fishes are very important as a group of ecologically and commercially important non-human biota and are often used as a bioindicators of aquatic pollution. Present work was carried out to assess the genotoxic effect of gamma radiation on fresh water fish Cyprinus carpio (common carp) in vivo using comet assay. Fishes were irradiated with 2, 4, 6, 8 and 10 Gy of gamma rays using a teletherapy machine and comet assay was performed on nucleated erythrocytes after 24, 48 and 72 h of irradiation . A significant increase in % tail DNA was observed at all the doses of gamma radiation as compared to controls indicating radiation induced DNA damage in a dose-dependent manner. Maximum % tail DNA was observed at 24 h which gradually declined till 72 h, in a time-dependent manner. This decrease in damage may indicate repair of the damaged DNA and or loss of heavily damaged cells, over a period of time. The study reveals that the comet assay may be used as a sensitive and rapid method to detect genotoxicity of gamma radiation and other environmental pollutants in sentinel species. (author)

  4. Comparative evaluation of genetic diversity using RAPD, SSR and ...

    Indian Academy of Sciences (India)

    1Department of Molecular Biology and Genetic Engineering, 2Ranichauri Hill Campus, G. B. Pant University of Agriculture ... Comparison of RAPD, SSR and cytochrome P450 gene based markers, in terms of the ...... project programme.

  5. Research for genetic instability of human genome

    International Nuclear Information System (INIS)

    Hori, T.; Takahashi, E.; Tsuji, H.; Yamauchi, M.; Murata, M.

    1992-01-01

    In the present review paper, the potential relevance of chromosomal fragile sites to carcinogenesis and mutagenesis is discussed based on our own and other's studies. Recent evidence indicate that fragile sites may act as predisposition factors involved in chromosomal instability of the human genome and that the sites may be preferential targets for various DNA damaging agents including ionizing radiation. It is also demonstrated that some critical genomic rearrangements at the fragile sites may contribute towards oncogenesis and that individuals carrying heritable form of fragile site may be at the risk. Although clinical significance of autosomal fragile sites has been a matter of discussion, a fragile site of the X chromosome is known to be associated with an X-linked genetic diseases, called fragile X syndrome. Molecular events leading to the fragile X syndrome have recently been elucidated. The fragile X genotype can be characterized by an increased amount of p(CCG)n repeat DNA sequence in the FMR-1 gene and the repeated sequences are shown to be unstable in both meiosis and mitosis. These repeats might exhibit higher mutation rate than is generally seen in the human genome. Further studies on the fragile sites in molecular biology and radiation biology will yield relevant data to the molecular mechanisms of genetic instability of the human genome as well as to better assessment of genetic effect of ionizing radiation. (author)

  6. Ionizing radiation in 21st century

    International Nuclear Information System (INIS)

    Jaworowski, Zbigniew

    2005-01-01

    The paper begins with the author's personal experience in Poland on the occasion of Chernobyl nuclear accident followed by main lessons that the author could deduce from the accident. After the discovery of ionizing radiation at the end of 19th century, social perception has altered between acceptance and rejection stemming from recognition of the basic aspects: usefulness for medical applications and for technical and scientific aims, beneficial effects of their low levels, and harmful effects of high levels. The author explains how linear no-threshold (LNT) assumption according to which even the lowest, near zero doses of radiation may cause cancer genetic harm has become established. Comparing the natural radioactivity of the earth's crust with the activity of much shorter-lived radioactive wastes from the nuclear power cycle, it is concluded that none of the man-made component of the radioactive wastes has higher-toxicity than the natural Th 232. The paper concludes by stating that one century has not been long enough to adapt mentally to ionizing radiation and radioactivity and perhaps 21st century will suffice for this adaptation. (S. Ohno)

  7. An inverse analysis of a transient 2-D conduction-radiation problem using the lattice Boltzmann method and the finite volume method coupled with the genetic algorithm

    International Nuclear Information System (INIS)

    Das, Ranjan; Mishra, Subhash C.; Ajith, M.; Uppaluri, R.

    2008-01-01

    This article deals with the simultaneous estimation of parameters in a 2-D transient conduction-radiation heat transfer problem. The homogeneous medium is assumed to be absorbing, emitting and scattering. The boundaries of the enclosure are diffuse gray. Three parameters, viz. the scattering albedo, the conduction-radiation parameter and the boundary emissivity, are simultaneously estimated by the inverse method involving the lattice Boltzmann method (LBM) and the finite volume method (FVM) in conjunction with the genetic algorithm (GA). In the direct method, the FVM is used for computing the radiative information while the LBM is used to solve the energy equation. The temperature field obtained in the direct method is used in the inverse method for simultaneous estimation of unknown parameters using the LBM-FVM and the GA. The LBM-FVM-GA combination has been found to accurately predict the unknown parameters

  8. Radiation risks in the 20. Century: reality, illusions and ethics

    International Nuclear Information System (INIS)

    Jaworowski, Z.

    1998-01-01

    Average global natural ionizing radiation dose for man is 2.4 mSv/year ranging in various geographical regions from about 1 to 220 mSv/year. At the dawn of life this dose was by a factor of three to five higher than now. The entire man-made contribution to radiation dose is only about 0.2% of natural radiation. From medical radiodiagnostics the average global dose is about 0.5 mSv/year, from nuclear explosions was in 1963 <0.2 mSv/year, from Chernobyl accident was in 1986-1987 0.05 mSv/year, and from nuclear power in 1995 about 0.007 mSv/year. Radiation is rather a weak noxious agent as compared with other natural and man-made hazards. Radiophobia has its source not in real peace-time radiation hazard to population, but in politics and group interests. Current excessive radiation protection standards, e.g. 1mSv/year, are based on an arbitrary assumption on linearity and a lack of threshold in dose/effect relationship, and on ignoring the beneficial effects of low doses of radiation. A whole body dose rate of 1mSv/year causes about 2 DNA damages in each cell. This can be compared with 70 million natural DNA damaging events occurring in each cell per year. Regulations based on this assumption lead to the wasting of resources desperately needed to deal with real health problems, and to strangulation of development of environmentally and human friendly nuclear technologies. Radiation standards should be based on 'practical threshold', one below which induction of detectable radiogenic cancers or genetic effects is not expected. (author)

  9. Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay.

    Science.gov (United States)

    Praveen Kumar, M K; Shyama, S K; Sonaye, B S; Naik, U Roshini; Kadam, S B; Bipin, P D; D'costa, A; Chaubey, R C

    2014-05-01

    Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of 'Comet assay' for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in both bivalve species. This showed a dose-dependent increase of genetic damage induced in bivalves by EMS as well as gamma radiation. Further, the highest DNA damage was observed at 24h. The damage gradually decreased with time, i.e. was smaller at 48 and 72 h than at 24h post irradiation in both species of bivalves. This may indicate repair of the damaged DNA and/or loss of heavily damaged cells as the post irradiation time advanced. The present study

  10. Health effects of ionizing radiation

    International Nuclear Information System (INIS)

    Radford, E.P.

    1980-01-01

    This presentation is restricted to the health effects of low doses of ionizing radiation. In general, these cumulative exposures are well below 100 rem, or about 50 times background or less. The two effects of interest in this dose range are genetic mutations and cancer production. The genetic effects will not be discussed in detail. The chief reason for the rise in risk estimates for cancer is the longer follow-up of exposed populations

  11. Radiation protection philosophy alters

    International Nuclear Information System (INIS)

    Firmin, G.

    1977-01-01

    Two significant events that have taken place this year in the field of radiation protection are reported. New SI units have been proposed (and effectively adopted), and the ICRP has revised its recommendations. Changes of emphasis in the latest recommendations (ICRP Publication 26) imply an altered radiation protection philosophy, in particular the relation of dose limits to estimates of average risk, an altered view of the critical organ approach and a new attitude to genetic dose to the population. (author)

  12. Radiation exposure of contrast-enhanced spectral mammography compared with full-field digital mammography.

    Science.gov (United States)

    Jeukens, Cécile R L P N; Lalji, Ulrich C; Meijer, Eduard; Bakija, Betina; Theunissen, Robin; Wildberger, Joachim E; Lobbes, Marc B I

    2014-10-01

    Contrast-enhanced spectral mammography (CESM) shows promising initial results but comes at the cost of increased dose as compared with full-field digital mammography (FFDM). We aimed to quantitatively assess the dose increase of CESM in comparison with FFDM. Radiation exposure-related data (such as kilovoltage, compressed breast thickness, glandularity, entrance skin air kerma (ESAK), and average glandular dose (AGD) were retrieved for 47 CESM and 715 FFDM patients. All examinations were performed on 1 mammography unit. Radiation dose values reported by the unit were validated by phantom measurements. Descriptive statistics of the patient data were generated using a statistical software package. Dose values reported by the mammography unit were in good qualitative agreement with those of phantom measurements. Mean ESAK was 10.5 mGy for a CESM exposure and 7.46 mGy for an FFDM exposure. Mean AGD for a CESM exposure was 2.80 mGy and 1.55 mGy for an FFDM exposure. Compared with our institutional FFDM, the AGD of a single CESM exposure is increased by 1.25 mGy (+81%), whereas ESAK is increased by 3.07 mGy (+41%). Dose values of both techniques meet the recommendations for maximum dose in mammography.

  13. A Comparative Study of Fuzzy Logic, Genetic Algorithm, and Gradient-Genetic Algorithm Optimization Methods for Solving the Unit Commitment Problem

    Directory of Open Access Journals (Sweden)

    Sahbi Marrouchi

    2014-01-01

    Full Text Available Due to the continuous increase of the population and the perpetual progress of industry, the energy management presents nowadays a relevant topic that concerns researchers in electrical engineering. Indeed, in order to establish a good exploitation of the electrical grid, it is necessary to solve technical and economic problems. This can only be done through the resolution of the Unit Commitment Problem. Unit Commitment Problem allows optimizing the combination of the production units’ states and determining their production planning, in order to satisfy the expected consumption with minimal cost during a specified period which varies usually from 24 hours to one week. However, each production unit has some constraints that make this problem complex, combinatorial, and nonlinear. This paper presents a comparative study between a strategy based on hybrid gradient-genetic algorithm method and two strategies based on metaheuristic methods, fuzzy logic, and genetic algorithm, in order to predict the combinations and the unit commitment scheduling of each production unit in one side and to minimize the total production cost in the other side. To test the performance of the optimization proposed strategies, strategies have been applied to the IEEE electrical network 14 busses and the obtained results are very promising.

  14. State-of-the-art cytogenetic techniques to detect radiation damage induced by low doses bin human lymphocytes

    International Nuclear Information System (INIS)

    Hadjidekova, V.

    2004-01-01

    Cytogenetic techniques are the most sensitive and reliable tools for bio-monitoring and bio-dosimetry of people professionally or accidentally exposed to ionizing radiation. They are applied in addition to the evaluations of the physical dosimetry and they consider the individual radiosensitivity. The main potential risk for humans from exposure to low doses of ionizing radiations is the enhanced incidence of stochastic effects, i.e. carcinogenesis and heritable genetic effects. This report presents a comparative evaluation of the cytogenetic markers for radiation damage of humans and general conclusions of cytogenetic studies of chromosomal aberrations and micronuclei formation in individuals occupationally exposed to action of ionizing radiation. The sensitivity of the methods is compared and their great development and mastering during the last years, as well as the basis of their application - the relation between the frequency of cytogenetic markers observed in lymphocytes in peripheral blood and the risk of malignant disease. The advantages and disadvantages of different cytogenetic techniques are discussed. (author)

  15. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment

    International Nuclear Information System (INIS)

    Rose, K.S.B.

    1988-01-01

    In this report, the health effects of low-level doses of radiation are considered by reference to published epidemiological surveys. The work was carried out with three objectives in mind: 1. to provide a comprehensive and critical review of the subject; 2. to seek consistent indications of particular health effects by collating results and comparing with those from surveys at moderate-level doses; 3. to provide an authoritative view on the epidemiology of low-level radiation-induced health effects. Vol E (DRAFT A) is appended and contains group collation tables. Epidemiological surveys can be conveniently divided into four classes (A, B, C, D) according to the phase of life when irradiation occurs or the effect is diagnosed. The first of the classes (A) is addressed here; this class is concerned with possible effects arising from radiation received by a parent before conception. Possible effects of preconception irradiation were identified under four broad groupings. These are Down's syndrome, ''Indicators of Reproductive Damage'' (mainly Primary Sterility, Congenital Abnormalities, Sex Ratio, Fetal Mortality, Infant Mortality), Childhood Malignancies, and Chromosomal Changes in Abortuses. Information about each survey, and comparisons with results from moderate-level dose surveys, are contained in synopses that are set out in the Appendix. (author)

  16. Domesticated, Genetically Engineered, and Wild Plant Relatives Exhibit Unintended Phenotypic Differences: A Comparative Meta-Analysis Profiling Rice, Canola, Maize, Sunflower, and Pumpkin

    Directory of Open Access Journals (Sweden)

    Alejandra Hernández-Terán

    2017-12-01

    Full Text Available Agronomic management of plants is a powerful evolutionary force acting on their populations. The management of cultivated plants is carried out by the traditional process of human selection or plant breeding and, more recently, by the technologies used in genetic engineering (GE. Even though crop modification through GE is aimed at specific traits, it is possible that other non-target traits can be affected by genetic modification due to the complex regulatory processes of plant metabolism and development. In this study, we conducted a meta-analysis profiling the phenotypic consequences of plant breeding and GE, and compared modified cultivars with wild relatives in five crops of global economic and cultural importance: rice, maize, canola, sunflower, and pumpkin. For these five species, we analyzed the literature with documentation of phenotypic traits that are potentially related to fitness for the same species in comparable conditions. The information was analyzed to evaluate whether the different processes of modification had influenced the phenotype in such a way as to cause statistical differences in the state of specific phenotypic traits or grouping of the organisms depending on their genetic origin [wild, domesticated with genetic engineering (domGE, and domesticated without genetic engineering (domNGE]. In addition, we tested the hypothesis that, given that transgenic plants are a construct designed to impact, in many cases, a single trait of the plant (e.g., lepidopteran resistance, the phenotypic differences between domGE and domNGE would be either less (or inexistent than between the wild and domesticated relatives (either domGE or domNGE. We conclude that (1 genetic modification (either by selective breeding or GE can be traced phenotypically when comparing wild relatives with their domesticated relatives (domGE and domNGE and (2 the existence and the magnitude of the phenotypic differences between domGE and domNGE of the same crop

  17. Ionizing radiation induced genomic instability and its relation to radiation carcinogenesis

    International Nuclear Information System (INIS)

    Wang Zhongwen

    2000-01-01

    There are widespread testimonies that the genomic instability induced by ionizing irradiation exits in mammal and its vitro cells. Genomic instability can enhance the frequency of genetic changes among the progeny of the original irradiated cells. In the radiation-leukemogenesis, there is no significant difference between controls and CBA/H mouses of PPI (preconception patent irradiation), but the offsprings of the PPI recipients show a different character (shorter latent period and higher incidence) after an extra γ-radiation. The radiation-induced genomic instability may get the genome on the verge of mutation and lead to carcinogens following mutation of some critical genes. The genomic instability, as the early event of initiation of carcinomas, may be play a specific or unique role

  18. Genetic consequences of the Chernobyl accident for Belarus republic

    International Nuclear Information System (INIS)

    Lazjuk, G.; Nikolaev, D.; Novikova, I.; Satow, Yukio

    1998-01-01

    Numerous studies have shown that a great number of residents in Belarus, Russia and the Ukraine were exposed to radiation due to radioactive nuclides ejected from the Chernobyl reactor, which increased genetic load, manifested in particular, as chromosome aberrations. The increase was registered for unstable and stable, chromatid and chromosome types of aberrations. Proceeding from the findings that the number of dicentric and ring chromosomes (which are the main indicator of radiation mutagenesis at chromosome level) was increasing simultaneously with the increase of other aberrations which are common for chemical mutagenesis and from the fact that actual mutation incidences exceeded the calculated figures for the doses obtained, one can not exclude the possibility that chromosome aberrations found in the population affected by the Chernobyl disaster are caused not only by ionizing radiation but also by various mutagens, and the doses based on physical dosimetry could be underestimated. It is quite obvious that the level of chromosome aberrations can be used as a biological indicator of harmful mutagenic effects on the organism. However, the method is not yet capable of (or only partially suited for) detecting the actual genetic risk even in the cases when aberrations are found in gametes, not in peripheral blood lymphocytes as usually done. The study of the dynamics of genetic losses, as spontaneous abortions and perinatal death due to inherited anomalies, and the study of the dynamics of malformed children births are probably the most reliable methods to determine genetic risk due to any mutagenic factor affecting the population, including ionizing radiation. This is related to the fact that there are a great sequence of events (gamete selection, preimplantation and embryonal death) occurring between gamete mutations (to say nothing about a somatic one) and births of children with congenital diseases. It is nearly impossible to count them and this leads to

  19. Genetic consequences of the Chernobyl accident for Belarus republic

    Energy Technology Data Exchange (ETDEWEB)

    Lazjuk, G.; Nikolaev, D.; Novikova, I. [Belarus Institute for Hereditary Diseases, Minsk (Belarus); Satow, Yukio

    1998-03-01

    Numerous studies have shown that a great number of residents in Belarus, Russia and the Ukraine were exposed to radiation due to radioactive nuclides ejected from the Chernobyl reactor, which increased genetic load, manifested in particular, as chromosome aberrations. The increase was registered for unstable and stable, chromatid and chromosome types of aberrations. Proceeding from the findings that the number of dicentric and ring chromosomes (which are the main indicator of radiation mutagenesis at chromosome level) was increasing simultaneously with the increase of other aberrations which are common for chemical mutagenesis and from the fact that actual mutation incidences exceeded the calculated figures for the doses obtained, one can not exclude the possibility that chromosome aberrations found in the population affected by the Chernobyl disaster are caused not only by ionizing radiation but also by various mutagens, and the doses based on physical dosimetry could be underestimated. It is quite obvious that the level of chromosome aberrations can be used as a biological indicator of harmful mutagenic effects on the organism. However, the method is not yet capable of (or only partially suited for) detecting the actual genetic risk even in the cases when aberrations are found in gametes, not in peripheral blood lymphocytes as usually done. The study of the dynamics of genetic losses, as spontaneous abortions and perinatal death due to inherited anomalies, and the study of the dynamics of malformed children births are probably the most reliable methods to determine genetic risk due to any mutagenic factor affecting the population, including ionizing radiation. This is related to the fact that there are a great sequence of events (gamete selection, preimplantation and embryonal death) occurring between gamete mutations (to say nothing about a somatic one) and births of children with congenital diseases. It is nearly impossible to count them and this leads to

  20. Radiation-induced genetic effects in germ cells of mammals

    International Nuclear Information System (INIS)

    Van der Schans, G.P.

    1993-01-01

    The objectives of the project are a better understanding of the fundamental principles that determine the radiation sensitivity in humans, with specific attention for the role of DNA repair in germ cells. The induction and repair of damage in DNA of germ cells of the Syrian golden hamster exposed to ionizing radiation is studied at biologically relevant doses. It has also been investigated which aspects of DNA sequence or chromosomal organisation are important with respect to their influence on the repairability of DNA damage. (R.P.) 10 refs

  1. Specific spheres of application of ionising radiation effects, some realized results and comparative advantages

    International Nuclear Information System (INIS)

    Benderac, R.

    2007-01-01

    The papers discusses some results of ionizing radiation effects in realization of non-destructive methods, achieved progress from the aspect of innovation, comparative results with previously used methods, etc. A review is given of methods based on alpha-radiography, auto-alpha radiography, beta-radiography, X-ray-fluorescent analysis, X- and gamma radiography, and photos of specific samples of neutron radiography [sr

  2. Comparing Artificial Intelligence and Genetic Engineering: Commercialization Lessons

    OpenAIRE

    Dickson, Edward M.

    1984-01-01

    Artificial Intelligence is rapidly leaving its academic home and moving into the marketplace. There are few precedents for an arcane academic subject becoming commercialized so rapidly. But, genetic engineering, which recently burst forth from academia to become the foundation for the hot new biotechnology industry, provides useful insights into the rites of passage awaiting the commercialization of artificial intelligence. This article examines the structural similarities and dissimilarities...

  3. A comparative study on genetic effects of artificial and natural habitat fragmentation on Loropetalum chinense (Hamamelidaceae) in Southeast China.

    Science.gov (United States)

    Yuan, N; Comes, H P; Cao, Y N; Guo, R; Zhang, Y H; Qiu, Y X

    2015-06-01

    Elucidating the demographic and landscape features that determine the genetic effects of habitat fragmentation has become fundamental to research in conservation and evolutionary biology. Land-bridge islands provide ideal study areas for investigating the genetic effects of habitat fragmentation at different temporal and spatial scales. In this context, we compared patterns of nuclear microsatellite variation between insular populations of a shrub of evergreen broad-leaved forest, Loropetalum chinense, from the artificially created Thousand-Island Lake (TIL) and the Holocene-dated Zhoushan Archipelago of Southeast China. Populations from the TIL region harboured higher levels of genetic diversity than those from the Zhoushan Archipelago, but these differences were not significant. There was no correlation between genetic diversity and most island features, excepting a negative effect of mainland-island distance on allelic richness and expected heterozygosity in the Zhoushan Archipelago. In general, levels of gene flow among island populations were moderate to high, and tests of alternative models of population history strongly favoured a gene flow-drift model over a pure drift model in each region. In sum, our results showed no obvious genetic effects of habitat fragmentation due to recent (artificial) or past (natural) island formation. Rather, they highlight the importance of gene flow (most likely via seed) in maintaining genetic variation and preventing inter-population differentiation in the face of habitat 'insularization' at different temporal and spatial scales.

  4. French invasive Asian tiger mosquito populations harbor reduced bacterial microbiota and genetic diversity compared to Vietnamese autochthonous relatives

    Directory of Open Access Journals (Sweden)

    Guillaume eMinard

    2015-09-01

    Full Text Available The Asian tiger mosquito Aedes a